Science.gov

Sample records for jaw diseases

  1. Diseases having an influence on inhibition of angiogenesis as risk factors of osteonecrosis of the jaw

    PubMed Central

    2016-01-01

    Objectives The objective of this study was to retrospectively investigate the association of diseases having an influence on inhibition of angiogenesis such as hypertension, diabetes mellitus type II, hypercholesterolemia, and rheumatoid arthritis (RA) with the development of osteonecrosis of the jaws. Materials and Methods The 135 patients were allocated into 4 groups of bisphosphonate-related osteonecrosis of the jaw (BRONJ) group (1A); non-BRONJ group (1B); osteonecrosis of the jaw (ONJ) group (2A); and control group (2B), according to histologic results and use of bisphosphonate. This retrospective study was conducted with patients who were treated in one institute from 2012 to 2013. Fisher's exact test and logistic regression analysis were used to analyze the odds ratios of diseases having an influence on inhibition of angiogenesis for development of ONJ. Results The effects of diabetes and hypertension were not statistically significant on development of ONJ. When not considering bisphosphonate use, RA exhibited a high odds ratio of 3.23 (P=0.094), while hyperlipidemia showed an odds ratio of 2.10 (P=0.144) for development of ONJ. More than one disease that had an influence on inhibition of angiogenesis showed a statistically significant odds ratio of 2.54 (P=0.012) for development of ONJ. Conclusion Patients without diseases having an influence on inhibition of angiogenesis were at less risk for developing ONJ. PMID:27847735

  2. Changes in activity and structure of jaw muscles in Parkinson's disease model rats.

    PubMed

    Nakamura, S; Kawai, N; Ohnuki, Y; Saeki, Y; Korfage, J A M; Langenbach, G E J; Kitayama, T; Watanabe, M; Sano, R; Tanne, K; Tanaka, E

    2013-03-01

    Parkinson's disease (PD), a major neurological disease, is characterised by a marked loss of dopaminergic neurons in the substantia nigra. Patients with PD frequently show chewing and swallowing dysfunctions, but little is known about the characteristics of their stomatognathic functions. The purpose of this study was to evaluate the influence of PD on jaw muscle fibre and functions. PD model rats were made by means of the injection of 6-hydroxydopamine (6-OHDA) into the striatum of 8-week-old Sprague-Dawley male rats. Five weeks after the injection, a radio-telemetric device was implanted to record muscle activity continuously from the superficial masseter and anterior belly of digastric muscles. Muscle activity was recorded for 3 days and was evaluated by the total duration of muscle activity per day (duty time). After recording the muscle activities, jaw muscles were isolated for immunohistochemical and PCR analyses. In PD model rats, the following findings of the digastrics muscles verify that compared to the control group: (i) the higher duty time exceeding 5% of the peak activity level, (ii) the higher expression of the mRNA of myosin heavy chain type I, and (iii) the tendency for fast to slow fibre-type transition. With respect to the masseter muscle, there were no significant differences in all analyses. In conclusion, PD leads to the changes in the jaw behaviours, resulting in a PD-specific chewing and swallowing dysfunctions.

  3. Bisphosphonates Cause Osteonecrosis of the Jaw-Like Disease in Mice

    PubMed Central

    Bi, Yanming; Gao, Yamei; Ehirchiou, Driss; Cao, Chunzhang; Kikuiri, Takashi; Le, Anh; Shi, Songtao; Zhang, Li

    2010-01-01

    Bisphosphonate-associated osteonecrosis of the jaw (BONJ) is a morbid bone disease linked to long-term bisphosphonate use. Despite its broad health impact, mechanistic study is lacking. In this study, we have established a mouse model of BONJ-like disease based on the equivalent clinical regimen in myeloma patients, a group associated with high risk of BONJ. We demonstrate that the murine BONJ-like disease recapitulates major clinical and radiographical manifestations of the human disease, including characteristic features of osseous sclerosis, sequestra, avascular, and radiopaque alveolar bone in the jaw that persists beyond a normal course of wound healing following tooth extraction. We find that long-term administration of bisphosphonates results in an increase in the size and number of osteoclasts and the formation of giant osteoclast-like cells within the alveolar bone. We show that the development of necrotic bone and impaired soft tissue healing in our mouse model is dependent on long-term use of high-dose bisphosphonates, immunosuppressive and chemotherapy drugs, as well as mechanical trauma. Most importantly, we demonstrate that bisphosphonate is the major cause of BONJ-like disease in mice, mediated in part by its ability to suppress osseous angiogenesis and bone remodeling. The availability of this novel mouse model of BONJ-like disease will help elucidate the pathophysiology of BONJ and ultimately develop novel approaches for prevention and treatment of human BONJ. PMID:20472893

  4. Bisphosphonates cause osteonecrosis of the jaw-like disease in mice.

    PubMed

    Bi, Yanming; Gao, Yamei; Ehirchiou, Driss; Cao, Chunzhang; Kikuiri, Takashi; Le, Anh; Shi, Songtao; Zhang, Li

    2010-07-01

    Bisphosphonate-associated osteonecrosis of the jaw (BONJ) is a morbid bone disease linked to long-term bisphosphonate use. Despite its broad health impact, mechanistic study is lacking. In this study, we have established a mouse model of BONJ-like disease based on the equivalent clinical regimen in myeloma patients, a group associated with high risk of BONJ. We demonstrate that the murine BONJ-like disease recapitulates major clinical and radiographical manifestations of the human disease, including characteristic features of osseous sclerosis, sequestra, avascular, and radiopaque alveolar bone in the jaw that persists beyond a normal course of wound healing following tooth extraction. We find that long-term administration of bisphosphonates results in an increase in the size and number of osteoclasts and the formation of giant osteoclast-like cells within the alveolar bone. We show that the development of necrotic bone and impaired soft tissue healing in our mouse model is dependent on long-term use of high-dose bisphosphonates, immunosuppressive and chemotherapy drugs, as well as mechanical trauma. Most importantly, we demonstrate that bisphosphonate is the major cause of BONJ-like disease in mice, mediated in part by its ability to suppress osseous angiogenesis and bone remodeling. The availability of this novel mouse model of BONJ-like disease will help elucidate the pathophysiology of BONJ and ultimately develop novel approaches for prevention and treatment of human BONJ.

  5. Periodontal Disease, Dental Implants, Extractions and Medications Related to Osteonecrosis of the Jaws.

    PubMed

    Shah, Neha P; Katsarelis, Helen; Pazianas, Michael; Dhariwal, Daljit K

    2015-11-01

    Patients taking bisphosphonates and other anti-resorptive drugs are likely to attend general dental practice. The term 'bisphosphonate'is often immediately associated with osteonecrosis of the jaws (ONJ). Risk assessment and subsequent management of these patients should be carried out taking into account all the risk factors associated with ONJ. The introduction of newer drugs, also shown to be associated with ONJ, demands increased awareness of general dental practitioners about these medications. CPD/CLINICAL RELEVANCE: This paper provides an update on medication-related ONJ and considers the effects of anti-resorptive drugs on the management of patients needing exodontia, treatment for periodontal disease and dental implant placement.

  6. Relation of bone turnover markers to periodontal disease and jaw bone morphology in elderly Japanese subjects.

    PubMed

    Yoshihara, A; Deguchi, T; Hanada, N; Miyazaki, H

    2009-03-01

    The purpose of this study was to evaluate the relation of bone turnover markers such as bone formation and resorption to periodontal disease and jaw bone morphology in elderly Japanese subjects. We selected 148 subjects for participation in this study. All subjects were aged 77 years. The periodontal examination included the assessment of clinical attachment level (CAL). Biochemical parameters of bone turnover measured included urinary deoxypyridinoline, serum osteocalcin (S-OC), and serum bone-specific alkaline phosphatase. In addition, to evaluate the jawbone, we used the mandibular inferior cortex classification (MIC). Serum osteocalcin had significantly higher (males: P = 0.038, females: P = 0.041) tendency for MIC Class (ANOVA). Multiple linear regression results showed that the number of remaining teeth and S-OC were negatively associated with the percentage of sites with > or =6 mm CAL (R(2) = 0.322, P < 0.001). Coefficients and betas were -0.71, -0.46 (P < 0.001) and -1.11, -0.28 (P = 0.002), respectively. In conclusion, this study suggests that there is a significant relation of bone turnover markers to periodontal disease and jaw bone morphology in elderly Japanese subjects.

  7. Periodontal Disease and Bisphosphonates Induce Osteonecrosis of the Jaws in the Rat

    PubMed Central

    Aghaloo, Tara L; Kang, Ben; Sung, Eric C; Shoff, Michael; Ronconi, Matthew; Gotcher, Jack E; Bezouglaia, Olga; Dry, Sarah M; Tetradis, Sotirios

    2012-01-01

    Bisphosphonates (BPs) are medications used commonly to treat primary and metastatic bone cancer, as well as osteoporosis. Although BPs improve bone mineral density, reduce fracture risk, and reduce hypercalcemia of malignancy, some patients develop BP-related osteonecrosis of the jaws (BRONJ). This devastating complication is defined as clinically exposed bone in the maxillofacial region for more than 8 weeks. Despite an increasing number of BRONJ cases since first reported, the disease pathophysiology remains largely unknown. Since published studies suggest a significant role for dental disease in the pathophysiology of BRONJ, we developed a BRONJ animal model where aggressive periodontal disease is induced by ligature placement around the crown of the right maxillary first molar in the presence of vehicle (veh) or zoledronic acid (ZA), a potent BP. Ligature placement induced significant alveolar bone loss, which was attenuated by ZA treatment. Osteonecrosis was observed associated with ligature-induced periodontitis in the ZA-treated group. This was seen as sequestration and extensive periosteal alveolar bone formation on micro–computed tomography (μCT) in the ligated site of BP-treated animals. Histologic examination confirmed these findings, seen as necrotic bone with diffuse loss of osteocytes and empty lacunae, rimming of the necrotic bone by squamous epithelium and inflammation, and exposure to the oral cavity. Importantly, the rat lesions were strikingly similar to those of BRONJ patients. Our data suggest that dental disease and potent BP therapy are sufficient for BRONJ development in the rat. PMID:21351151

  8. Periapical disease and bisphosphonates induce osteonecrosis of the jaws in mice.

    PubMed

    Kang, Ben; Cheong, Simon; Chaichanasakul, Thawinee; Bezouglaia, Olga; Atti, Elisa; Dry, Sarah M; Pirih, Flavia Q; Aghaloo, Tara L; Tetradis, Sotirios

    2013-07-01

    Osteonecrosis of the jaw (ONJ) is a well-recognized complication of antiresorptive medications, such as bisphosphonates (BPs). Although ONJ is most common after tooth extractions in patients receiving high-dose BPs, many patients do not experience oral trauma. Animal models using tooth extractions and high BP doses recapitulate several clinical, radiographic, and histologic findings of ONJ. We and others have reported on rat models of ONJ using experimental dental disease in the absence of tooth extraction. These models emphasize the importance of dental infection/inflammation for ONJ development. Here, we extend our original report in the rat, and present a mouse model of ONJ in the presence of dental disease. Mice were injected with high dose zoledronic acid and pulpal exposure of mandibular molars was performed to induce periapical disease. After 8 weeks, quantitative and qualitative radiographic and histologic analyses of mouse mandibles were done. Periapical lesions were larger in vehicle-treated versus BP-treated mice. Importantly, radiographic features resembling clinical ONJ, including thickening of the lamina dura, periosteal bone deposition, and increased trabecular density, were seen in the drilled site of BP-treated animals. Histologically, osteonecrosis, periosteal thickening, periosteal bone apposition, epithelial migration, and bone exposure were present in the BP-treated animals in the presence of periapical disease. No difference in tartrate-resistant acid phosphatase (TRAP)+ cell numbers was observed, but round, detached, and removed from the bone surface cells were present in BP-treated animals. Although 88% of the BP-treated animals showed areas of osteonecrosis in the dental disease site, only 33% developed bone exposure, suggesting that osteonecrosis precedes bone exposure. Our data further emphasize the importance of dental disease in ONJ development, provide qualitative and quantitative measures of ONJ, and present a novel mouse ONJ model in

  9. Periapical Disease and Bisphosphonates Induce Osteonecrosis of the Jaws in Mice

    PubMed Central

    Kang, Ben; Cheong, Simon; Chaichanasakul, Thawinee; Bezouglaia, Olga; Atti, Elisa; Dry, Sarah M; Pirih, Flavia Q; Aghaloo, Tara L.; Tetradis, Sotirios

    2013-01-01

    Osteonecrosis of the jaw (ONJ) is a well-recognized complication of antiresorptive medications, such as bisphosphonates (BPs). Although ONJ is most common after tooth extractions in patients receiving high dose BPs, many patients do not experience oral trauma. Animal models utilizing tooth extractions and high BP doses recapitulate several clinical, radiographic and histologic findings of ONJ. We and others have reported on rat models of ONJ utilizing experimental dental disease in the absence of tooth extraction. These models emphasize the importance of dental infection/inflammation for ONJ development. Here, we extend our original report in the rat, and present a mouse model of ONJ in the presence of dental disease. Mice were injected with high dose zoledronic acid and pulpal exposure of mandibular molars was performed to induce periapical disease. After 8 weeks, quantitative and qualitative radiographic and histologic analyses of mouse mandibles were executed. Periapical lesions were larger in vehicle- vs. BP treated mice. Importantly, radiographic features resembling clinical ONJ, including thickening of the lamina dura, periosteal bone deposition and increased trabecular density, were seen in the drilled site of BP treated animals. Histologically, osteonecrosis, periosteal thickening, periosteal bone apposition, epithelial migration and bone exposure were present in the BP treated animals in the presence of periapical disease. No difference in TRAP+ cell numbers was observed, but round, detached, and removed from the bone surface cells were present in BP animals. Although 88% of the BP animals showed areas of osteonecrosis in the dental disease site, only 33% developed bone exposure, suggesting that osteonecrosis precedes bone exposure. Our data further emphasize the importance of dental disease in ONJ development, provide qualitative and quantitative measures of ONJ, and present a novel mouse ONJ model in the absence of tooth extraction that should be useful

  10. Periodontal disease and bisphosphonates induce osteonecrosis of the jaws in the rat.

    PubMed

    Aghaloo, Tara L; Kang, Ben; Sung, Eric C; Shoff, Michael; Ronconi, Matthew; Gotcher, Jack E; Bezouglaia, Olga; Dry, Sarah M; Tetradis, Sotirios

    2011-08-01

    Bisphosphonates (BPs) are medications used commonly to treat primary and metastatic bone cancer, as well as osteoporosis. Although BPs improve bone mineral density, reduce fracture risk, and reduce hypercalcemia of malignancy, some patients develop BP-related osteonecrosis of the jaws (BRONJ). This devastating complication is defined as clinically exposed bone in the maxillofacial region for more than 8 weeks. Despite an increasing number of BRONJ cases since first reported, the disease pathophysiology remains largely unknown. Since published studies suggest a significant role for dental disease in the pathophysiology of BRONJ, we developed a BRONJ animal model where aggressive periodontal disease is induced by ligature placement around the crown of the right maxillary first molar in the presence of vehicle (veh) or zoledronic acid (ZA), a potent BP. Ligature placement induced significant alveolar bone loss, which was attenuated by ZA treatment. Osteonecrosis was observed associated with ligature-induced periodontitis in the ZA-treated group. This was seen as sequestration and extensive periosteal alveolar bone formation on micro-computed tomography (µCT) in the ligated site of BP-treated animals. Histologic examination confirmed these findings, seen as necrotic bone with diffuse loss of osteocytes and empty lacunae, rimming of the necrotic bone by squamous epithelium and inflammation, and exposure to the oral cavity. Importantly, the rat lesions were strikingly similar to those of BRONJ patients. Our data suggest that dental disease and potent BP therapy are sufficient for BRONJ development in the rat. Copyright © 2011 American Society for Bone and Mineral Research.

  11. Relationship between disease stage and renal function in bisphosphonate-related osteonecrosis of the jaw

    PubMed Central

    2017-01-01

    Objectives Bisphosphonate is the primary cause of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Bisphosphonates are eliminated from the human body by the kidneys. It is anticipated that bisphosphonate levels in the body will increase if the kidney is in a weak state or if there is systemic disease that affects kidney function. The aim of this study was to analyze the relevance of renal function in the severity of BRONJ. Materials and Methods Ninety-three patients diagnosed with BRONJ in Pusan National University Dental Hospital from January 2012 to December 2014 were included in this study. All patients underwent a clinical exam, radiographs, and serologic lab test, including urine analysis. The patient's medical history was also taken, including the type of bisphosphonate drug, the duration of administration and drug holiday, route of administration, and other systemic diseases. In accordance with the guidelines of the 2009 position paper of American Association of Oral and Maxillofacial Surgeons, the BRONJ stage was divided into 4 groups, from stage 0 to 3, according to the severity of disease. IBM SPSS Statistics version 21.0 (IBM Co., USA) was used to perform regression analysis with a 0.05% significance level. Results BRONJ stage and renal factor (estimated glomerular filtration rate) showed a moderate statistically significant correlation. In the group with higher BRONJ stage, the creatinine level was higher, but the increase was not statistically significant. Other factors showed no significant correlation with BRONJ stage. There was a high statistically significant correlation between BRONJ stage and ‘responder group’ and ‘non-responder group,’ but there was no significant difference with the ‘worsened group.’ In addition, the age of the patients was a relative factor with BRONJ stage. Conclusion With older age and lower renal function, BRONJ is more severe, and there may be a decrease in patient response to treatment. PMID:28280705

  12. Role of periodontal disease in bisphosphonate-related osteonecrosis of the jaws in ovariectomized rats.

    PubMed

    Li, Chun Lei; Lu, Weijia William; Seneviratne, Chaminda Jayampath; Leung, Wai Keung; Zwahlen, Roger A; Zheng, Li Wu

    2016-01-01

    This study aimed to investigate the role of progressive periodontal disease in inducing bisphosphonate-related osteonecrosis of the jaws (BRONJ) using an ovariectomized (OVX) rat model mimicking human intracortical remodeling process. Thirty 12-week-old Spraque-Dawly (SD) female rats were randomly assigned into two groups. All rats underwent bilateral ovariectomy. Six weeks after surgery, zoledronic acid (ZA) or vehicle control was administered intraperitoneally for 12 weeks. On the same day of injection, a cotton ligature was placed subgingivally around the first left lower molar to induce periodontitis. All animals were sacrificed 12 weeks after injection. The entire mandibles were harvested for micro-computed tomography (micro-CT) and histological examinations. Micro-CT examination showed that ligature placement caused significant alveolar bone loss both in ZA (0.63 ± 0.13 vs. 0.38 ± 0.06 mm, P < 0.001) and in control (0.88 ± 0.19 vs. 0.40 ± 0.06 mm, P < 0.001) groups. Whereas in the ZA group, bone loss was attenuated compared with the control group (P < 0.01); the bone mineral density in the ZA group (1.00 ± 0.02 g/cm(3)) was significantly higher than that in vehicle control group (0.96 ± 0.03 g/cm(3), P < 0.001). Histological examination found necrotic bone tissue with extensive, empty lacunae in two of 15 rats in ZA group, but in none of the control group. Bisphosphonates inhibit alveolar bone resorption in progressive periodontal disease, which might benefit the management of periodontitis, but increase the risk of developing BRONJ. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Staging of osteonecrosis of the jaw requires computed tomography for accurate definition of the extent of bony disease.

    PubMed

    Bedogni, Alberto; Fedele, Stefano; Bedogni, Giorgio; Scoletta, Matteo; Favia, Gianfranco; Colella, Giuseppe; Agrillo, Alessandro; Bettini, Giordana; Di Fede, Olga; Oteri, Giacomo; Fusco, Vittorio; Gabriele, Mario; Ottolenghi, Livia; Valsecchi, Stefano; Porter, Stephen; Petruzzi, Massimo; Arduino, Paolo; D'Amato, Salvatore; Ungari, Claudio; Fung Polly, Pok-Lam; Saia, Giorgia; Campisi, Giuseppina

    2014-09-01

    Management of osteonecrosis of the jaw associated with antiresorptive agents is challenging, and outcomes are unpredictable. The severity of disease is the main guide to management, and can help to predict prognosis. Most available staging systems for osteonecrosis, including the widely-used American Association of Oral and Maxillofacial Surgeons (AAOMS) system, classify severity on the basis of clinical and radiographic findings. However, clinical inspection and radiography are limited in their ability to identify the extent of necrotic bone disease compared with computed tomography (CT). We have organised a large multicentre retrospective study (known as MISSION) to investigate the agreement between the AAOMS staging system and the extent of osteonecrosis of the jaw (focal compared with diffuse involvement of bone) as detected on CT. We studied 799 patients with detailed clinical phenotyping who had CT images taken. Features of diffuse bone disease were identified on CT within all AAOMS stages (20%, 8%, 48%, and 24% of patients in stages 0, 1, 2, and 3, respectively). Of the patients classified as stage 0, 110/192 (57%) had diffuse disease on CT, and about 1 in 3 with CT evidence of diffuse bone disease was misclassified by the AAOMS system as having stages 0 and 1 osteonecrosis. In addition, more than a third of patients with AAOMS stage 2 (142/405, 35%) had focal bone disease on CT. We conclude that the AAOMS staging system does not correctly identify the extent of bony disease in patients with osteonecrosis of the jaw. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Periodontal disease as a risk factor for bisphosphonate-related osteonecrosis of the jaw.

    PubMed

    Thumbigere-Math, Vivek; Michalowicz, Bryan S; Hodges, James S; Tsai, Michaela L; Swenson, Karen K; Rockwell, Laura; Gopalakrishnan, Rajaram

    2014-02-01

    Previous case reports and animal studies suggest that periodontitis is associated with bisphosphonate-related osteonecrosis of the jaw (BRONJ). This case-control study is conducted to evaluate the association between clinical and radiographic measures of periodontal disease and BRONJ. Twenty-five patients with BRONJ were matched with 48 controls. Trained examiners measured probing depth, clinical attachment level (CAL), and bleeding on probing on all teeth except third molars and gingival and plaque indices on six index teeth. Alveolar bone height was measured from orthopantomograms. Most patients with BRONJ were using antibiotics (48%) or a chlorhexidine mouthrinse (84%) at enrollment. Adjusted comparisons of patients with BRONJ versus controls used multiple linear regression. The average number of bisphosphonate (BP) infusions was significantly higher in patients with BRONJ compared with controls (38.4 versus 18.8, P = 0.0001). In unadjusted analyses, patients with BRONJ had more missing teeth (7.8 versus 3.1, P = 0.002) and higher average CAL (2.18 versus 1.56 mm, P = 0.047) and percentage of sites with CAL ≥3 mm (39.0 versus 23.3, P = 0.039) than controls. Also, patients with BRONJ had lower average bone height (as a fraction of tooth length, 0.59 versus 0.62, P = 0.004) and more teeth with bone height less than half of tooth length (20% versus 6%, P = 0.001). These differences remained significant after adjusting for age, sex, smoking, and number of BP infusions. BRONJ patients have fewer teeth, greater CAL, and less alveolar bone support compared with controls after adjusting for number of BP infusions. Group differences in antibiotics and chlorhexidine rinse usage may have masked differences in the other clinical measures.

  15. Periodontal Disease as a Risk Factor for Bisphosphonate-Related Osteonecrosis of the Jaw

    PubMed Central

    Thumbigere-Math, Vivek; Michalowicz, Bryan S.; Hodges, James S.; Tsai, Michaela L.; Swenson, Karen K.; Rockwell, Laura; Gopalakrishnan, Rajaram

    2014-01-01

    Background Previous case reports and animal studies suggest periodontitis is associated with bisphosphonate-related osteonecrosis of the jaw (BRONJ). We conducted a case-control study to evaluate the association between clinical and radiographic measures of periodontal disease and BRONJ. Methods 25 BRONJ patients were matched with 48 controls. Trained examiners measured probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) on all teeth except third molars, and gingival and plaque indices on six index teeth. Alveolar bone height was measured from orthopantomograms. Most BRONJ cases were using antibiotics (48%) or a chlorhexidine mouthrinse (84%) at enrollment. Adjusted comparisons of cases vs. controls used multiple linear regression. Results The average number of BP infusions was significantly higher in BRONJ cases compared to controls (38.4 vs 18.8, p=0.0001). In unadjusted analyses, BRONJ cases had more missing teeth (7.8 vs 3.1, p=0.002) and high average CAL (2.18 vs 1.56 mm, p=0.047) and percent of sites with CAL ≥3 mm (39.0 vs 23.3, p=0.039) than controls. Also, BRONJ cases had lower average bone height (as a fraction of tooth length, 0.59 vs 0.62, p=0.004) and more teeth with bone height under half of tooth length (20% vs 6%, p=0.001). These differences remained significant after adjusting for age, sex, smoking, and number of bisphosphonate infusions. Conclusions BRONJ patients have fewer teeth, greater CAL, and less alveolar bone support compared to controls after adjusting for number of bisphosphonate infusions. Group differences in antibiotics and chlorhexidine rinse usage may have masked differences in the other clinical measures. PMID:23786404

  16. Osteonecrosis of the jaw.

    PubMed

    Sambrook, Philip N; Ebeling, Peter

    2008-04-01

    Bisphosphonates are effective therapy for osteoporosis, Paget's disease, and metastatic bone disease. Generally, the side effects of bisphosphonates are minimal. Recently, an uncommon adverse reaction affecting the maxilla or mandible, called osteonecrosis of the jaw, has been reported, especially in those patients receiving high doses of bisphosphonates in the oncology setting. Regarding doses used to treat osteoporosis, clinicians must keep the very small potential absolute risk of jaw osteonecrosis in perspective and consider it in relation to the demonstrated benefit of bisphosphonates. Still, in a very small number of patients taking bisphosphonates, intractable, painful, nonhealing exposed bone may occur following dental extractions or denture irritation.

  17. Jaw Injuries and Disorders

    MedlinePlus

    ... Jaw problems include Fractures Dislocations Temporomandibular joint dysfunction Osteonecrosis, which happens when your bones lose their blood supply Cancers Treatment of jaw problems depends on the cause.

  18. Plasma endotoxin activity in kangaroos with oral necrobacillosis (lumpy jaw disease) using an automated handheld testing system.

    PubMed

    Sotohira, Yukari; Suzuki, Kazuyuki; Sasaki, Haruka; Sano, Tadashi; Tsuchiya, Masakazu; Suzuki, Yohko; Shimamori, Toshio; Tsukano, Kenji; Sato, Ayano; Yokota, Hiroshi; Asakawa, Mitsuhiko

    2016-07-01

    The aim of the present study was to evaluate the reliability and effectiveness of directly determining endotoxin activity in plasma samples from kangaroos with lumpy jaw disease (LJD, n=15) and healthy controls (n=12). Prior to the present study, the ability of the commercially available automated handheld portable test system (PTS(TM)) to detect endotoxin activity in kangaroo plasma was compared with that of the traditional LAL-kinetic turbidimetric (KT) assay. Plasma samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTS(TM) was not significantly different from that of the traditional LAL-based assay. The data obtained using PTS(TM) correlated with those using KT (r(2)=0.963, P<0.001). These findings indicated that the PTS(TM) is applicable as a simplified system to assess endotoxin activity in macropods. In the present study, we demonstrated the diagnostic value of plasma endotoxin activity in kangaroos with systemic inflammation caused by oral necrobacillosis and identified plasma endotoxin activity as a sensitive marker of systemic inflammation in kangaroos with LJD. Based on ROC curves, we proposed a diagnostic cut-off point for endotoxin activity of >0.22 EU/ml for the identification of LJD. Our results indicate that the assessment of plasma endotoxin activity is a promising diagnostic tool for determining the outcome of LJD in captive macropods.

  19. [Jaws of primitive mammals].

    PubMed

    Tsubamoto, Takehisa

    2005-06-01

    Some of main osteological differences between mammals and reptiles are seen in the number of bones that constitute lower jaw and in jaw articulation. A lower jaw of mammals consists of only one bone, while in reptiles it consists of several bones (e.g., four to six in lizards and five in crocodiles). The jaw articulation in mammals is performed by squamosal of the skull and the mandible ( = dentary), while in reptiles it is done by quadrate of the skull and articular of the lower jaw. When mammals first appeared about 200 million years ago in the Mesozoic Era, the jaws of primitive mammals were morphologically intermediate between those of reptiles and typical mammals. Here, I briefly introduce the evolution of lower jaw morphology from the reptilian one to the mammalian one, showing lower jaw features of some mammal-like reptiles and primitive mammals.

  20. Jaw and Order

    ERIC Educational Resources Information Center

    Mooshammer, Christine; Hoole, Philip; Geumann, Anja

    2007-01-01

    It is well-accepted that the jaw plays an active role in influencing vowel height. The general aim of the current study is to further investigate the extent to which the jaw is active in producing consonantal distinctions, with specific focus on coronal consonants. Therefore, tongue tip and jaw positions are compared for the German coronal…

  1. Osteonecrosis of the jaw in a Crohn’s disease patient following a course of Bisphosphonate and Adalimumab therapy: a case report

    PubMed Central

    2014-01-01

    Background Bisphosphonates have a widespread indication for osteoporosis and are also applied in cancer patients with skeletal-related conditions. Bisphosphonate-associated osteonecrosis of the jaw (BRONJ) is a feared side effect which is hard to treat and often affects patient´s quality of life in an extensive manner. Adalimumab (Humira®), a fully human recombinant antibody specific for tumor necrosis factor- α, is approved for treatment in patients with Inflammatory Bowel Disease like ulcerative colitis or Crohn’s disease. Case presentation In March 2013, a 36-year-old female presented with right-sided perimandibular swelling, recurrent facial pain and exposed necrotic bone after previous extraction of tooth 47. She had the medical history of Crohn’s disease for more than one decade with chronic active enterocolitis, fistula disease as well as previous oral manifestation and was currently treated with Adalimumab since September 2008. Due to steroid-induced osteoporosis, diagnosed in 2004, she received oral Bisphosphonates (Risedronate) from 2004 until 2007 followed by two infusions of Zoledronic acid in 2008 and 2009. Conclusion This patient with a medical history of Crohn’s disease and gastrointestinal remission under Adalimumab therapy presented with osteonecrosis of the jaw after suspended oral and intravenous Bisphosphonate therapy implicating that the biologic therapy with an anti-TNF-α antibody might promote the manifestation of osteonecrosis and compromise oral healing capacity. PMID:24400722

  2. Osteonecrosis of the jaw due to bisphosphonates.

    PubMed

    2008-10-01

    Bisphosphonates are widely used to treat osteoporosis, bone complications of cancer, malignant hypercalcaemia and Paget's disease. Osteonecrosis of the jaw is a major adverse effect of these drugs. It can affect eating, interpersonal relations, and physical appearance. Ulceration of the tongue and nerve involvement can also occur. Osteonecrosis of the jaw due to bisphosphonates is mainly seen in cancer patients, and more rarely in patients treated for osteoporosis. Between 5% and 11% of cancer patients treated with bisphosphonates develop osteonecrosis of the jaw. The frequency of jaw osteonecrosis increases with the duration of bisphosphonate treatment and is higher in case of recent dental work. The main bisphosphonate withdrawal and surgery are rarely effective. In practice, when bisphosphonate therapy is needed, the patient must be informed of the risks, should seek dental care (if possible) before starting treatment, see a dentist regularly, and consult a doctor in case of delayed healing after dental extraction, jaw pain, or numbness.

  3. A Geometric Classification of Jaw Deformities

    PubMed Central

    Gateno, Jaime; Alfi, David; Xia, James J.; Teichgraeber, John F.

    2015-01-01

    In the United States, the most widely used classification system for jaw deformities is the one provided by the International Classification of Diseases, Clinical Modification (ICD-CM), a taxonomy scheme that is based on the World Health Organization's International Classification of Diseases (ICD). The last iteration of ICD-CM, version 10, sorts jaw deformities according to geometry, into 3 groups: anomalies of jaw size, anomalies of jaw-cranial base relationship, or unspecified. Yet these deformities can affect 6 different geometric attributes: size, position, orientation, shape, symmetry, and completeness. In clinical practice and in teaching we have found the ICD-CM classification to be incomplete and disjointed. With this in mind, we have developed a better classification system. The purpose of this paper is to present it. PMID:26608152

  4. Patients Receiving Parenteral Bisphosphonates for Malignant Disease and Having Developed an Atypical Femoral Fracture Are at Risk of Concomitant Osteonecrosis of the Jaw: An Evidence-Based Review.

    PubMed

    Graves, Lindsay L; Bukata, Susan V; Aghazadehsanai, Nona; Chang, Tina I; Garrett, Neal R; Friedlander, Arthur H

    2016-12-01

    The risk of developing concomitant medication-related osteonecrosis of the jaw (MRONJ) in patients who have sustained an atypical femoral fracture (AFF) in association with parental administration of a bisphosphonate osteoclastic inhibitor medication for malignant disease is unclear. Published data were searched to determine the prevalence of these concomitant adverse medication events, if any. A systematic review of published case series in the PubMed database was undertaken to ascertain the prevalence of patients having a concomitant history of AFF and MRONJ. The data were analyzed to provide prevalence rates of these events from the literature. Two case series were identified that delineated the risk (25 and 33%, respectively) of concomitant development of MRONJ and AFF in recipients of parenteral bisphosphonate medication administered for malignant disease. The published data suggest that approximately 30% of patients receiving parenteral bisphosphonates and having sustained an AFF could develop comorbid MRONJ. Published by Elsevier Inc.

  5. Denosumab and anti-angiogenetic drug-related osteonecrosis of the jaw: an uncommon but potentially severe disease.

    PubMed

    Sivolella, Stefano; Lumachi, Franco; Stellini, Edoardo; Favero, Lorenzo

    2013-05-01

    Osteonecrosis of the jaw (ONJ) is a rare but serious lesion of the jaw characterized by exposed necrotic bone and is related to several drugs usually used for treating patients with advanced malignancies. Common therapies inducing ONJ are nitrogen-containing bisphosphonates (BPs), the human monoclonal antibody to the receptor activator of nuclear factor-kappa B ligand denosumab and some anti-angiogenic drugs, alone or in combination with BPs. The real incidence of ONJ is unknown. Several cases of ONJ in patients with cancer who underwent denosumab therapy have been reported and it seems that the overall incidence of denosumab-related ONJ is similar to that for BP-related in this population, ranging between 1-2%. The cell-surface vascular endothelial growth factor (VEGF) receptor plays a major role in cancer progression and can be targeted by drugs inhibiting the tyrosine kinase activator or other second messengers. Most angiogenesis inhibitors, such as the monoclonal antibody bevacizumab and the kinase inhibitor sunitinib, target the VEGF signaling pathway. Unfortunately, cases of bevacizumab-induced ONJ have been reported, especially in patients treated with bevacizumab and BPs in combination. There are only few studies reporting sunitinib-related ONJs. In patients with advanced cancer and malignancy-associated hypercalcemia undergoing BP, denosumab or bevacizumab therapy, enquiry into current dental health and dental examination is mandatory. Good oral hygiene, limiting of alcohol intake and stopping smoking should be suggested for all patients requiring such treatments.

  6. Jaw - broken or dislocated

    MedlinePlus

    ... This may be due to: Assault Industrial accident Motor vehicle accident Recreational or sports injury Trips and falls ... Hold the jaw gently in place with your hands on the way to the emergency room. You ...

  7. [Jaws of herbivorous mammals].

    PubMed

    Konishi, Shogo

    2005-08-01

    The jaws of herbivorous mammals are characterized by their large occlusal surface of the molar; high crown of the molar; long snout; etc. However, elephants, the biggest herbivorous mammal, have other characteristics. In the evolutionary trends of proboscidean skulls, concomitant with the increase in tusk size comes on the enlargement, antero-posterior shortening, dorso-ventral elongation of the cranium with increasing cheek teeth size. Naturally, the jaw follows the same evolutionary trends as the cranium.

  8. [Jaws of amphibians and reptiles].

    PubMed

    Tanimoto, Masahiro

    2005-04-01

    Big jaws of amphibians and reptiles are mainly treated in this article. In amphibians enlarged skulls are for the big jaw in contrast with human's skulls for the brain. For example, famous fossils of Homo diluvii testis are ones of salamanders in fact. In reptiles, mosasaur jaws and teeth and their ecology are introduced for instance.

  9. [Paget´s disease of the mandible: a differential diagnosis of the osteomyelitis of the jaw].

    PubMed

    Pausch, Niels Christian; Hemprich, Alexander; Halama, Dirk

    2014-01-01

    Paget´s disease of bone is a common, progressive disorder with uncertain etiology. It results in the replacement of normal skeletal areas with highly vascularized, low density bone. The most frequent symptom is bone pain, which is a result of periostal irritation due to increased metabolic activity. However, the disease may run without any symptoms. In these cases, an abnormal radiograph or an elevated serum alkaline phosphatase can indicate the disorder. Most cases are discovered accidentally. The average age of patients at the time of diagnosis is about 50 years. Male individuals are preferentially diseased. Paget´s disease affects either single bone (monostotic) or many bones (polyostotic). It typically involves the pelvis, femur and lumbar spine rather than skull and tibia. In the head and neck area, the skull is the most frequently affected localization. Lesions of the mandible and maxilla are less common. For the therapy of active Paget´s disease, antiresorptive agents like bisphosphonates are effective drugs. Additional treatment with analgesic drugs, antiinflammatory and antineuropathic agents is recommended. We present a case of polyostotic Paget´s disease of the mandible and of the thoracic skeleton.

  10. Drug induced osteonecrosis of the jaw.

    PubMed

    Hamadeh, Issam S; Ngwa, Bridget A; Gong, Yan

    2015-05-01

    Despite the widespread use of bisphosphonates and their unequivocal efficacy for the treatment of various disease states, osteonecrosis of the jaw remains one of the most feared complications associated with their use. Current evidence, however, suggests that there is also a relationship between occurrence of osteonecrosis of the jaw and use of other classes of pharmacotherapies namely RANKL inhibitors as well as angiogenesis inhibitors. Although these drugs have different mechanisms of action than bisphosphonates, they all seem to interfere with the bone remodeling process i.e. alter the balance between bone resorption and bone formation which may be the most plausible explanation for pathogenesis of osteonecrosis of the jaw. The main objective of this review is to introduce the readership to a number of relatively new medications that may cause osteonecrosis of the jaw. Accordingly, we will summarize latest findings from clinical studies, meta analyses and case reports published in medical literature on this topic. For some of these medications, the evidence may not appear as robust as that for bisphosphonates; yet, the possibility of this adverse event occurring with these non bisphosphonate drugs should never be precluded unless proven otherwise. Thus, it is imperative that health care providers implement preventive measures so as to circumvent the incidence of osteonecrosis of the jaw. In this day of age where medical care is becoming personalized, we will highlight some of significant findings from studies seeking to identify genetic markers that may potentially play a role in development of osteonecrosis of the jaw. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Ewing's tumor of the jaw.

    PubMed

    Wood, R E; Nortje, C J; Hesseling, P; Grotepass, F

    1990-01-01

    Previous reports have focused on the fact that laminar periosteal new bone is a common radiologic sign of Ewing's sarcoma of the jaws. Critical analysis of the literature does not lead to this conclusion. A case is reported and radiologic appearances described. A review of the literature shows striking clinical and radiologic similarities to osteogenic sarcoma of the jaws. A differential radiologic interpretation of Ewing's sarcoma of the jaws is offered.

  12. Development of teeth and jaws in the earliest jawed vertebrates.

    PubMed

    Rücklin, Martin; Donoghue, Philip C J; Johanson, Zerina; Trinajstic, Kate; Marone, Federica; Stampanoni, Marco

    2012-11-29

    Teeth and jaws constitute a model of the evolutionary developmental biology concept of modularity and they have been considered the key innovations underpinning a classic example of adaptive radiation. However, their evolutionary origins are much debated. Placoderms comprise an extinct sister clade or grade to the clade containing chondrichthyans and osteichthyans, and although they clearly possess jaws, previous studies have suggested that they lack teeth, that they possess convergently evolved tooth-like structures or that they possess true teeth. Here we use synchrotron radiation X-ray tomographic microscopy (SRXTM) of a developmental series of Compagopiscis croucheri (Arthrodira) to show that placoderm jaws are composed of distinct cartilages and gnathal ossifications in both jaws, and a dermal element in the lower jaw. The gnathal ossification is a composite of distinct teeth that developed in succession, polarized along three distinct vectors, comparable to tooth families. The teeth are composed of dentine and bone, and show a distinct pulp cavity that is infilled centripetally as development proceeds. This pattern is repeated in other placoderms, but differs from the structure and development of tooth-like structures in the postbranchial lamina and dermal skeleton of Compagopiscis and other placoderms. We interpret this evidence to indicate that Compagopiscis and other arthrodires possessed teeth, but that tooth and jaw development was not developmentally or structurally integrated in placoderms. Teeth did not evolve convergently among the extant and extinct classes of early jawed vertebrates but, rather, successional teeth evolved within the gnathostome stem-lineage soon after the origin of jaws. The chimaeric developmental origin of this model of modularity reflects the distinct evolutionary origins of teeth and of component elements of the jaws.

  13. Bisphosphonates and osteonecrosis of the jaws: science and rationale.

    PubMed

    Gutta, Rajesh; Louis, Patrick J

    2007-08-01

    Bisphosphonates as a group of drugs were introduced for the management of various conditions such as osteoporosis, Paget's disease, multiple myeloma, hypercalcemia of malignancy, breast cancer, prostate cancer, and other tumors. This group of drugs has improved the quality of life in many patients with proven efficacy in limiting pain and skeletal-related events. The controversy of osteonecrosis of the jaws and bisphosphonates is a recent and growing problem. Osteonecrosis of the jaws is recognized as a serious complication of bisphosphonate therapy, more commonly with the intravenous form of the drugs. However, there is limited scientific understanding about the association between osteonecrosis of the jaws and bisphosphonates. In the present article we discuss various mechanisms of action of bisphosphonates, the rationale for occurrence of osteonecrosis in the jaws, and treatment guidelines for the condition.

  14. Human jaw and muscle modelling.

    PubMed

    Peck, Christopher C; Hannam, Alan G

    2007-04-01

    Dynamic mathematical modelling is an invaluable method to help understand the biomechanics of the anatomically and functionally complex masticatory system. It provides insight into variables which are impossible to measure directly such as joint loads and individual muscle tensions, and into physical relationships between jaw structure and function. Individual parameters can be modified easily to understand their influence on function. Our models are constructed with best available structural and functional data, and evaluated against human jaw behaviour. Image data provide hard and soft tissue morphology and the jaw's inertial properties. The drive to the system is provided by actuators which simulate active and passive jaw muscle properties. In whole-jaw modelling, muscle models which behave plausibly rather than mimic the ultra-structural cross-bridge interactions are common since they are computationally feasible. Whole-jaw models have recently incorporated flexible finite-elements to explore tissue distortion in the temporomandibular joint and tongue movements. Furthermore, the jaw has been integrated with laryngeal models to explore complex tasks such as swallowing. These dynamic models have helped better understand joint loading, movement constraints and muscle activation strategies. Future directions will include further incorporation of rigid and flexible model dynamics and the creation of subject-specific models to better understand the functional implications of pathology.

  15. A method for studying jaw muscle activity during standardized jaw movements under experimental jaw muscle pain.

    PubMed

    Sae-Lee, Daraporn; Wanigaratne, Kamal; Whittle, Terry; Peck, Christopher C; Murray, Greg M

    2006-10-30

    This paper describes a method for studying superficial and deep jaw muscle activity during standardized jaw movements under experimental jaw muscle pain. In 22 healthy adults, pain was elicited in the right masseter muscle via tonic infusion of 4.5% hypertonic saline and which resulted in scores of 30-60 mm on a 100-mm visual analogue scale. Subjects performed tasks in five sessions in a repeated measures design, i.e., control 1, test 1 (during hypertonic or isotonic saline infusion), control 2 (without infusion), test 2 (during isotonic or hypertonic saline infusion), control 3 (without infusion). During each session, subjects performed maximal clenching and standardized jaw tasks, i.e., protrusion, lateral excursion, open/close, chewing. Mandibular movement was recorded with a 6-degree-of-freedom tracking system simultaneously with electromyographic (EMG) activity from the inferior head of the lateral pterygoid muscle with fine-wire electrodes (verified by computer tomography), and from posterior temporalis, the submandibular muscle group and bilateral masseter muscles with surface electrodes. EMG root mean square values were calculated at each 0.5 mm increment of mandibular incisor movement for all tasks under each experimental session. This establishes an experimental model for testing the effects of pain on jaw muscle activity where the jaw motor system is required to perform goal-directed tasks, and therefore should extend our understanding of the effects of pain on the jaw motor system.

  16. [Bisphosphonate-related osteonecrosis of the jaw].

    PubMed

    Atanes-Bonome, P; Atanes-Bonome, A; Ríos-Lage, P; Atanes-Sandoval, A D

    2014-04-01

    The bisphosphonates are stable inorganic pyrophosphate analogs that have demonstrated their efficacy in treatment of osteolytic lesions associated with bony metastases, and multiple myeloma, malignant hypercalcemia, Paget's disease, and osteoporosis. Several publications within the last few years have suggested that osteonecrosis of the jaw is associated with bisphosphonate therapy. The diagnosis and management strategies of the patients with bisphosphonate-related osteonecrosis of the jaw is very difficult. It is important for patients to be informed of the risk of this complication, so that they have the opportunity to assess the need for dental treatment before starting therapy. Preventive measures must be taken before, during, and after treatment with bisphosphonates. If osteonecrosis of the jaw is present, management should be conservative: oral chlorhexidine and antibiotics. Surgical treatment should be reserved for those patients who are symptomatic. Copyright © 2013 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

  17. [Bisphosphonate-associated osteonecrosis of the jaw].

    PubMed

    Koy, S; Schubert, M; Koy, J; Ney, M; Lauer, G; Sabatowski, R

    2015-04-01

    Bisphosphonates (BP) are used in the treatment of severe osteoporosis and metastasis of malignant diseases. A possible relationship between the occurrence of osteonecrosis of the jaw and BP therapy was first described in 2003. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is difficult to treat. In some cases the condition of the patients is so compromised that only minimally invasive surgery is possible. Histopathologically, osteonecrosis shows the features of chronic sequestered osteomyelitis, which can be found in different areas of the upper and lower jaw. Sometimes extensive resections of the jaw are necessary. Thus, BRONJ can cause mutilation, impairment of function and esthetics in the orofacial system and, thereby, compromise the life quality of the patients. Triggering factors are often tooth extraction without surgical plastic wound closure of the alveoli, but can also be associated with bruises from denture or other minor wounds. The purpose of this article is to present results from our own patient collective, including therapy regime, success rate, and therapy recommendations. The patient populations at three German hospitals were analyzed using a standard questionnaire. The patients in the study group, entered into a follow-up system for early detection of possible BRONJ, were evaluated for treatement outcome. The success rate for prophylactic surgery in asymptomatic patients was very high at 96 %. In the group with symptomatic BRONJ, the outcome was significantly lower (76.4 %). Because of the complex symptoms, close cooperation between oncologists, dentists, and maxillofacial surgeons is required in the treatment of BRONJ. Before starting therapy with bisphosphonates and during the therapy, dental treatment and monitoring of the patient' oral health is necessary.

  18. Pediatric jaw tumors: Our experience.

    PubMed

    Saxena, Susmita; Kumar, Sanjeev; Pundir, Siddharth

    2012-01-01

    Reports of series of central jaw tumours in children are rare hence predicting their biological behaviour as well as treatment, prognosis have not been documented from this part of the world. To study retrospectively, the paediatric central jaw tumours, reported to our institute with relation to site of occurrence, presentation and biological behaviour. All consecutive patients (<18 years), between 2004-2010, histologically diagnosed as having an intraosseous tumour or tumour-like lesions formed the study population. Patients fulfilling the inclusion criteria were only considered for further study. The entire study material was analyzed and grouped into various categories for logical conclusions. The data accumulated were grouped, entered and analyzed. Sixty-one cases fulfilled the criteria. Gender distribution was equal, with mandible predominance (2.2:1) and a predominance of non-odontogenic lesions (2:1). There were 4 malignant and 57 benign conditions. Anterior jaw lesions were 23 while 38 were present in the posterior region of jaws (1:1:6). The pattern of central jaw tumours presentation in children from this part of India has been documented. In this study, paediatric jaw tumours are less common compared to those in adults with non-odontogenic tumours being common. The finding of the present study indicates that an impacted tooth, beyond the eruption time deserves more attention for the reason of associated pathologies in children.

  19. Solitary plasmacytoma of the jaw

    PubMed Central

    Marotta, Serena; Di Micco, Pierpaolo

    2010-01-01

    Solitary plasmacytoma may be considered as a rare neoplasm of head and neck and is a different disease compared to multiple myeloma. The main difference is related to the better clinical prognosis of solitary plasmacytoma, which may be clinically silent for several years but several local recurrences may be possible once diagnosed and treated. Clinical signs and symptoms of solitary plasmacytoma are related to bone pain and possible bone fractures. Partial local impairment of local bone function may be present. Bone swelling and local involvement of mucosa and local soft tissue may be revealed. Systemic findings related to the production of monoclonal protein are usually not present and a monoclonal spike in serum electrophoresis may be absent as the monoclonal Bence–Jones protein in the urine. Other systemic dysfunctions as systemic bone marrow involvement with related anemia and absent thrombocytopenia. However, although very rare, solitary plasmacytoma of the jaw may have several clinical presentations and here we review clinical differences reported in the literature. PMID:22282681

  20. Surgical treatment of jaw osteonecrosis in "Krokodil" drug addicted patients.

    PubMed

    Poghosyan, Yuri M; Hakobyan, Koryun A; Poghosyan, Anna Yu; Avetisyan, Eduard K

    2014-12-01

    Retrospective study of jaw osteonecrosis treatment in patients using the "Krokodil" drug from 2009 to 2013. On the territory of the former USSR countries there is widespread use of a self-produced drug called "Krokodil". Codeine containing analgesics ("Sedalgin", "Pentalgin" etc), red phosphorus (from match boxes) and other easily acquired chemical components are used for synthesis of this drug, which used intravenously. Jaw osteonecrosis develops as a complication in patients who use "Krokodil". The main feature of this disease is jawbone exposure in the oral cavity. Surgery is the main method for the treatment of jaw osteonecrosis in patients using "Krokodil". 40 "Krokodil" drug addict patients with jaw osteonecrosis were treated. Involvement of maxilla was found in 11 patients (27.5%), mandible in 21 (52.5%), both jaws in 8 (20%) patients. 35 Lesions were found in 29 mandibles and 21 lesions in 19 maxillas. Main factors of treatment success are: cessation of "Krokodil" use in the pre- (minimum 1 month) and postoperative period and osteonecrosis area resection of a minimum of 0.5 cm beyond the visible borders of osteonecrosis towards the healthy tissues. Surgery was not delayed until sequestrum formation. In the mandible marginal or segmental resection (with or without TMJ exarticulation) was performed. After surgery recurrence of disease was seen in 8 (23%) cases in the mandible, with no cases of recurrence in the maxilla. According to our experience in this case series, surgery is the main method for the treatment of jaw osteonecrosis in patients using "Krokodil". Cessation of drug use and jaw resection minimize the rate of recurrences in such patients.

  1. Bisphosphonates and osteonecrosis of the jaw.

    PubMed

    Sambrook, Philip; Olver, Ian; Goss, Alastair

    2006-10-01

    Recently an association between bisphosphonate use and a rare dental condition termed 'osteonecrosis of the jaw' (ONJ) has been reported. Patients with osteoporosis and Paget disease who take bisphosphonates have a significantly reduced risk of fracture and other skeletal complications. This represents significant health benefits, against which the small risk of ONJ needs to be considered. In patients with bone malignancy, the risk of ONJ needs to be balanced against the benefit of therapy on the underlying malignancy. There are still many uncertainties about this condition. This position paper seeks to summarise what is currently known about ONJ to provide information to medical practitioners and dental practitioners.

  2. Factors associated with osteonecrosis of the jaw among bisphosponate users

    PubMed Central

    Hess, Lisa M; Jeter, Joanne M; Benham-Hutchins, Marge; Alberts, David S.

    2008-01-01

    Background Bisphosphonates are medications that impact bone reformation by inhibiting osteoclast function. Osteonecrosis of the jaw has been reported among patients receiving these medications. It is unclear if the risk factors associated with osteonecrosis of the jaw among cancer patients taking bisphosphonates are also possible risk factors among patients receiving these medications for other indications. Methods A systematic review search strategy was used to identify cases of osteonecrosis of the jaw among patients taking bisphosphonates for an indication other than cancer to identify potential contributing factors. Data were analyzed according to previous models to develop a more expanded model that may explain possible mechanisms for the development of osteonecrosis of the jaw among patients without cancer. Results Ninety-nine cases of osteonecrosis of the jaw were identified among patients who were prescribed a bisphosphonate for an indication other than cancer. These cases included 85 osteoporosis patients, 10 patients with Paget’s disease, two patients with rheumatoid arthritis, one patient with diabetes and one patient with maxillary fibrous dysplasia. The mean age was 69.4 years, 87.3% were female, and 87.6% were receiving oral, but not intravenous, bisphosphonates. Of the 63 patients reporting dental care information, 88.9% had a dental procedure prior to the onset of osteonecrosis of the jaw. Of all cases providing medical information, 71% were taking at least one medication that affects bone turnover in addition to the bisphosphonate, and 81.6% reported additional underlying health conditions. Conclusions The case details suggest a multiplicity of factors associated with this condition and provide the foundation for a model outlining the potential mechanism for the development of osteonecrosis of the jaw among patients taking bisphosphonates for an indication other than cancer. PMID:18501224

  3. Jaw stretch reflexes in children.

    PubMed

    Finan, Donald S; Smith, Anne

    2005-07-01

    The substantial morphological transformations that occur during human development present the nervous system with a considerable challenge in terms of motor control. Variability of skilled motor performance is a hallmark of a developing system. In adults, the jaw stretch reflex contributes to the functional stability of the jaw. We have investigated the response properties of the jaw stretch reflex in two groups of young children and a group of young adults. Response latencies increased with development, and all age groups produced stimulus-magnitude-dependent increases in reflex gain and resulting biting force. Reflex gain was largest for the older children (9-10 years), yet net increases in resulting biting force were comparable across age groups. These data and earlier experiments suggest that oral sensorimotor pathways mature throughout childhood in concert with the continued acquisition of complex motor skills.

  4. Bisphosphonates and osteonecrosis of the jaw.

    PubMed

    Shannon, Jodi; Shannon, John; Modelevsky, Steven; Grippo, Anne A

    2011-12-01

    Bisphosphonates are used worldwide as a successful treatment for people with osteoporosis, which is the major underlying cause of fractures in postmenopausal women and older adults. These agents are successful at increasing bone mass and bone trabecular thickness, decreasing the risk of fracture, and decreasing bone pain, enabling individuals to have better quality of life. Bisphosphonates are also used to treat multiple myeloma, bone metastasis, and Paget's disease; however, bisphosphonate treatment may result in negative side effects, including osteonecrosis of the jaw (ONJ). ONJ involves necrotic, exposed bone in the jaw, pain, possible secondary infection, swelling, painful lesions, and various dysesthesias, although less-severe cases may be asymptomatic. First-generation bisphosphonates, which do not contain nitrogen, are metabolized into a nonfunctional, cytotoxic analogue of adenosine triphosphate and cause osteoclast death by starvation. Second-generation bisphosphonates are nitrogen-containing agents; these inhibit osteoclast vesicular trafficking, membrane ruffling, morphology, and cytoskeletal arrangement by inhibiting farnesyl diphosphate synthase in the mevalonate pathway. Physicians treating older adults with osteoporosis and cancer should work together with dental practitioners, pharmacists, and other clinicians to inform individuals receiving bisphosphonates of their possible side effects and to suggest precautionary steps that may minimize the risk of osteonecrosis, particularly of the jaw. These include practicing good oral hygiene; scheduling regular dental examinations and cleanings; and cautioning people who are scheduling treatment for periodontal disease, oral and maxillofacial therapy, endodontics, implant placement, restorative dentistry, and prosthodontics. Recommendations for management of people with ONJ include an oral rinse, such as chlorhexidine, and antibiotics. © 2011, Copyright the Authors Journal compilation © 2011, The American

  5. Introduction to the JAWS Program

    NASA Technical Reports Server (NTRS)

    Mccarthy, John

    1987-01-01

    The JAWS Project is the Joint Airport Weather Studies project conceived in 1980 jointly between the National Center for Atmospheric Research and the Univ. of Chicago. The objectives of the program are threefold: (1) Basic scientific characterization of the microbursts and the statistics of microbursts occurrence; (2) Detection and warning, using the Low Level Wind Shear Alert System (LLWSAS) operation and performance; and (3) Doppler radar and airborne systems. These goals and the operation of the JAWS system in general are discussed in detail.

  6. Neuromuscular interaction of jaw and neck muscles during jaw clenching.

    PubMed

    Giannakopoulos, Nikolaos Nikitas; Hellmann, Daniel; Schmitter, Marc; Krüger, Bastian; Hauser, Thomas; Schindler, Hans J

    2013-01-01

    To test the hypothesis that jaw muscles and specific neck muscles, ie, levator scapulae, trapezius, sternocleidomastoideus, and splenius capitis, co-contract at the different submaximum bite forces usually generated during jaw clenching and tooth grinding, and for different bite force directions. Bite-force transducers that measured all three spatial force components were incorporated in 11 healthy subjects. The test persons developed feedback-controlled submaximum bite forces in a variety of bite-force directions. The electromyographic (EMG) activity of the levator scapulae, splenius capitis, and trapezius muscles was recorded, at the level of the fifth cervical vertebra, by use of intramuscular wire electrodes. The activity of the sternocleidomastoideus and masseter muscles was recorded by surface electrodes. For normalization of the EMG data, maximum-effort tasks of the neck muscles were conducted in eight different loading directions by means of a special force-transducer system. Differences between neck-muscle activity during chewing, maximum biting in intercuspation, and the force-controlled motor tasks were compared with the baseline activity of the various muscles by one-way repeated-measures analysis of variance. The results confirmed the hypothesis. Co-contractions of the neck muscles in the range of 3% to 10% of maximum voluntary contraction were observed. Significant (P < .05) activity differences were recorded as a result of the different force levels and force directions exerted by the jaw muscles. Long-lasting action potential trains of single motor units triggered by jaw clenching tasks were also detected. The findings support the assumption of a relationship between jaw clenching and the neck muscle activity investigated. The low level of co-contraction activity, however, requires further study to elucidate possible pathophysiological interactions at the level of single motor units.

  7. Functional Morphology of Eunicidan (Polychaeta) Jaws

    NASA Astrophysics Data System (ADS)

    Clemo, W. C.; Dorgan, K. M.

    2016-02-01

    Polychaetes exhibit diverse feeding strategies and diets, with some species possessing hardened teeth or jaws of varying complexity. Species in the order Eunicida have complex, rigidly articulated jaws consisting of multiple pairs of maxillae and a pair of mandibles. While all Eunicida possess this general jaw structure, a number of characteristics of the jaw parts vary considerably among families. These differences, described for fossilized and extant species' jaws, were used to infer evolutionary relationships, but current phylogeny shows that jaw structures that are similar among several families are convergent. Little has been done, however, to relate jaw functional morphology and feeding behavior to diet. To explore these relationships, we compared the jaw kinematics of two taxa with similar but evolutionarily convergent jaw structures: Diopatra (Onuphidae) and Lumbrineris (Lumbrineridae). Diopatra species are tube-dwelling and predominantly herbivorous, whereas Lumbrineris species are burrowing carnivores. Jaw kinematics were observed and analyzed by filming individuals biting or feeding and tracking tooth movements in videos. Differences in jaw structure and kinematics between Diopatra and Lumbrineris can be interpreted to be consistent with their differences in diet. Relating jaw morphology to diet would provide insight into early annelid communities by linking fossil teeth (scolecodonts) to the ecological roles of extant species with similar morphologies.

  8. Periodontal disease preceding osteonecrosis of the jaw (ONJ) in cancer patients receiving antiresorptives alone or combined with targeted therapies: report of 5 cases and literature review.

    PubMed

    Nicolatou-Galitis, Ourania; Razis, Evangelia; Galiti, Dimitra; Galitis, Evangelos; Labropoulos, Stefanos; Tsimpidakis, Antonis; Sgouros, Joseph; Karampeazis, Athanasios; Migliorati, Cesar

    2015-12-01

    We present clinical and radiologic data of periodontal tissue involvement preceding the appearance of osteonecrosis of the jaw (ONJ) in 5 patients with solid tumors, who received antiresorptives alone or in combination with targeted therapies. Five patients with osteonecrosis before dental extraction were studied. Periodontal involvement was evidenced by pain, bleeding, fistula, purulence, swelling, periodontal pocket, and tooth mobility. Combined endoperiodontal lesions were considered in 1 patient. Duration of symptoms before ONJ diagnosis lasted 8 to 24 weeks. Routine therapy was performed in 2 of 5 patients. Widening of the periodontal ligament was observed in 4 patients, and dense alveolar bone was seen in 1 patient. Local complications of ONJ required dental extractions in 4 of 5 patients. Spontaneous tooth exfoliation was observed in 1 patient. Alveolar bone biopsies, after the extraction in 2 patients, confirmed osteonecrosis. Osteonecrosis healed in 2 patients--1 after the dental extraction and 1 after 3 dental extractions and surgical debridement. Postextraction socket healed in 1 patient, and the area with exposed bone remained asymptomatic. Osteonecrosis progressed in 2 patients. Clinical and radiologic signs of periodontal tissue involvement, before dental extraction in patients treated with antiresorptives alone or in combination with targeted therapy, may represent developing osteonecrosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Jaw osteonecrosis in patients treated with bisphosphonates: an ultrastructural study.

    PubMed

    Perrotta, I; Cristofaro, M G; Amantea, M; Russo, E; De Fazio, S; Zuccalà, V; Conforti, F; Amorosi, A; Donato, G; Tripepi, S; Giudice, M

    2010-08-01

    Osteonecrosis of the jaw is a severe bone disorder traditionally associated with periodontal disease, local malignancy, chemotherapy, glucocorticoid therapy, or trauma. Recently a growing number of publications reported the occurrence of osteonecrosis of the jaw in patients undergoing treatment with bisphosphonates. The mechanism by which bisphosphonates might contribute to the development of osteonecrosis of the jaw is far from being fully elucidated. Suppression of bone turnover, infection, tissue hypoxia and cellular toxicity were proposed as possible mechanisms by which bisphosphonates may exert adverse effects on bone metabolism. Here, we studied 25 consecutive patients treated with bisphosphonates for osteoporosis or tumoral pathologies. We provide good evidence of hyperactive osteoclastic bone resorption and suggest a direct cytotoxic effect of bisphosphonates on bone tissue through induction of osteocyte cell death. We also demonstrate that bisphosphonates only have limited adverse effects on bone vascular network.

  10. Adalimumab: Another Medication Related to Osteonecrosis of the Jaws?

    PubMed Central

    Cassoni, Andrea; Romeo, Umberto; Terenzi, Valentina; Della Monaca, Marco; Rajabtork Zadeh, Oriana; Raponi, Ingrid; Fadda, Maria Teresa; Polimeni, Antonella; Valentini, Valentino

    2016-01-01

    Objective. The acronym MRONJ has been created in order to identify “Medication-Related Osteonecrosis of the Jaw,” observed after the use of Bisphosphonates, RANK ligand inhibitor, and antiangiogenic medications. Only a case of osteonecrosis of the jaw in a Chron's disease patient following a course of Bisphosphonate and Adalimumab therapy has been recently described, so that it has been supposed that also this medication could promote manifestation of osteonecrosis. Clinical Case. On August, 2014, a 63-year-old female with a history of idiopathic arthritis treated with medical treatment with Adalimumab from 2010 to 2013 presented referring pain in the right mandible. Results. This patient presented with nonexposed osteonecrosis of the jaw after placement, on September, 2010, of four titanium fixtures in the mandible. Conclusions. The authors suggest that the biologic therapy with an anti-TNF-α antibody might promote the manifestation of osteonecrosis and compromise oral healing capacity of the bone. PMID:27088019

  11. Adalimumab: Another Medication Related to Osteonecrosis of the Jaws?

    PubMed

    Cassoni, Andrea; Romeo, Umberto; Terenzi, Valentina; Della Monaca, Marco; Rajabtork Zadeh, Oriana; Raponi, Ingrid; Fadda, Maria Teresa; Polimeni, Antonella; Valentini, Valentino

    2016-01-01

    Objective. The acronym MRONJ has been created in order to identify "Medication-Related Osteonecrosis of the Jaw," observed after the use of Bisphosphonates, RANK ligand inhibitor, and antiangiogenic medications. Only a case of osteonecrosis of the jaw in a Chron's disease patient following a course of Bisphosphonate and Adalimumab therapy has been recently described, so that it has been supposed that also this medication could promote manifestation of osteonecrosis. Clinical Case. On August, 2014, a 63-year-old female with a history of idiopathic arthritis treated with medical treatment with Adalimumab from 2010 to 2013 presented referring pain in the right mandible. Results. This patient presented with nonexposed osteonecrosis of the jaw after placement, on September, 2010, of four titanium fixtures in the mandible. Conclusions. The authors suggest that the biologic therapy with an anti-TNF-α antibody might promote the manifestation of osteonecrosis and compromise oral healing capacity of the bone.

  12. Bisphophonates related osteonecrosis of the jaw

    PubMed Central

    Gupta, Swati; Gupta, Hemant; Mandhyan, Devendra; Srivastava, Sanjeev

    2013-01-01

    Objective: With sporadic reporting of BPs related osteonecrosis of jaw and in absence of definitive guidelines regarding the management of such patients, the dentists and the oral and maxillofacial surgeons need to be updated about this issue. The objective of this article was to produce an updated bibliographic review of BPs related ONJ. This paper reviews the literature regarding the same for better understanding of the problem and its management. Background: Bisphosphonates (BPs) are potent inhibitors of bone resorption and are widely used in the treatment of osteoporosis and other diseases that cause bone mass loss, such as Paget's disease, bone metastases, and multiple myeloma, to prevent pathological fractures. With increasing use, evidence is emerging that patients taking BP drugs are at risk of developing osteonecrosis of the jaws (ONJs), sometimes occurring spontaneously, but more commonly following dental extractions or oral bone surgery. Materials and Methods: A bibliographic search was carried out using PubMed, Medline, and search engines ending in April, 2013. The search terms used were: Oral BPs, dental implants, and osteonecrosis. Conclusion: On the basis of available literature, the management of patients on bisphosphonates requiring dental treatment is classified according to the duration of BPs treatment, method of administration of BPs etc. Dental treatments when planned carefully in such patients have a fair to good prognosis. PMID:24665168

  13. [Bisphosphonate and osteonecrosis of the jaw.

    PubMed

    Taguchi, Akira

    Marx first reported avascular osteonecrosis of the jaw(ONJ)in oncology patients who had used high dose intravenous bisphosphonate(BP)at 2003. Ruggiero et al. also reported BP-related ONJ in osteoporosis patients who had used low dose oral BP at 2004. Since tooth extraction was considered one of risk factors for ONJ, discontinuation of BP before and after tooth extraction was recommended as one of preventive strategy for ONJ, especially in osteoporosis patients. However, recent studies showed that discontinuation of BP did not prevent ONJ, but increased the occurrence of adverse events such as fracture. Best strategies for preventing ONJ include elimination of oral disease such as periodontal and/or periapical diseases prior to initiation of BP, as well as maintenance of good oral hygiene. Development of a strategy for sharing information about ONJ among physicians, dentists, and patients is required to reduce the incidence of ONJ.

  14. 21 CFR 872.2060 - Jaw tracking device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Jaw tracking device. 872.2060 Section 872.2060...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.2060 Jaw tracking device. (a) Jaw tracking device for monitoring mandibular jaw positions relative to the maxilla—(1) Identification. A jaw tracking...

  15. 21 CFR 872.2060 - Jaw tracking device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Jaw tracking device. 872.2060 Section 872.2060...) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.2060 Jaw tracking device. (a) Jaw tracking device for monitoring mandibular jaw positions relative to the maxilla—(1) Identification. A jaw tracking...

  16. "Phossy Jaw" and "Bis-phossy Jaw" of the 19th and the 21st Centuries: The Diuturnity of John Walker and the Friction Match.

    PubMed

    Pollock, Richard A; Brown, Ted W; Rubin, David M

    2015-09-01

    Some 200 years ago, workers developed gingivitis, periodontal disease, alveolar crest bone sequestra, and draining fistulae after exposure to phosphorous fumes and phosphorous paste in the manufacture of the friction match. Many also suffered loss of teeth and pathologic fracture of the mandible. Known as "phossy jaw," the constellation rather abruptly vanished following the International Berne Convention of 1906. Today, "bis-phossy jaw" (bisphosphonate-induced osteonecrosis of the jaw) has surfaced with pathologic fractures and other features common to its predecessor, "phossy jaw." This modern equivalent is reported with ever-increasing frequency and is presented here in the format of a brief historical review and a case report that includes segmental en bloc extirpation of necrotic mandible and pain-free salvage. Computerized imagery and three-dimensional printing technology were successfully chosen to create and apply a custom titanium bone plate, without free-tissue transfer.

  17. Focal dystonia of the jaw and the differential diagnosis of unilateral jaw and masticatory spasm.

    PubMed Central

    Thompson, P D; Obeso, J A; Delgado, G; Gallego, J; Marsden, C D

    1986-01-01

    The clinical features, differential diagnosis and treatment of unilateral spasms of the jaw and masticatory muscles are discussed and illustrated by eight cases of unilateral jaw spasms of various aetiologies. These include focal dystonia of the jaw, hemimasticatory spasm with and without facial hemiatrophy, paroxysmal events in multiple sclerosis and tetany. Attention is particularly drawn to four cases of unilateral dystonia of the jaw which has not been described before. Images PMID:3734821

  18. Self-aligning lathe chuck jaws

    DOEpatents

    Not Available

    1980-08-26

    A lathe chuck jaw for a lathe chuck having a radially moving actuator which radially moves the jaw into and out from the workpiece is described. A jaw base part is rigidly connected to the actuator. A jaw shoe part is rotatably attached to the base part. The shoe part has a workpiece-conforming surface which can hold the workpiece. The rotatable attachment of the shoe part allows it to match the general orientation of the workpiece, including a nonlongitudinal orientation due to a workpiece's imperfect shape.

  19. Self-aligning lathe chuck jaws

    SciTech Connect

    Peterson, William R.

    1982-01-01

    A lathe chuck jaw for a lathe chuck having a radially moving actuator which radially moves the jaw in to and out from the workpiece. A jaw base part is rigidly connected to the actuator. A jaw shoe part is rotatably attached to the base part. The shoe part has a workpiece-comforming surface which can hold the workpiece. The rotatable attachment of the shoe part allows it to match the general orientation of the workpiece, including a nonlongitudinal orientation due to a workpiece's imperfect shape.

  20. Self-aligning lathe chuck jaws

    SciTech Connect

    Peterson, W.R.

    1982-10-12

    A lathe chuck jaw for a lathe chuck having a radially moving actuator which radially moves the jaw in to and out from the workpiece. A jaw base part is rigidly connected to the actuator. A jaw shoe part is rotatably attached to the base part. The shoe part has a workpiece-comforming surface which can hold the workpiece. The rotatable attachment of the shoe part allows it to match the general orientation of the workpiece, including a nonlongitudinal orientation due to a workpiece's imperfect shape.

  1. Osteonecrosis of the jaw in older osteoporosis patients treated with intravenous bisphosphonates.

    PubMed

    Baillargeon, Jacques; Kuo, Yong Fang; Lin, Yu-Li; Wilkinson, Gregg S; Goodwin, James S

    2011-10-01

    Intravenous bisphosphonate therapy has been linked to osteo-necrosis of the jaw among patients with cancer. Some patients with osteoporosis also receive intravenous bisphosphonates, although at lower total doses than those with cancer. To examine the risk for jaw osteonecrosis among a population-based cohort of older adults receiving intravenous bisphosphonates for the treatment of osteoporosis. Using a 5% national sample of Medicare beneficiaries, we identified 2296 patients treated with intravenous infusions of bisphosphonates for osteoporosis and other metabolic bone diseases between January 1, 2000, and December 31, 2007. We matched this cohort to 6865 bisphosphonate nonusers, at a 1:3 ratio, on age, race, sex, type of bone disease, and risk factors for osteonecrosis of the jaw. Patients were followed until December 31, 2007. The jaw toxicity outcomes included operations on the facial bones or jaw and diagnosis of inflammatory conditions of the jaw. The absolute risk at 3 years for any jaw toxicity was 0.70 events per 100 patients using bisphosphonates and 0.30 events per 100 patients not using such drugs (2-sided log rank test, p = 0.08). In multivariable survival analyses (Cox proportional hazards regression) adjusting for potential confounders, intravenous bisphosphonate use was not significantly associated with diagnoses or procedures suggestive of osteonecrosis of the jaw (p = 0.24). Patients with osteoporosis who are treated with intravenous bisphosphonates do not appear to have a statistically significant increase in the incidence of osteonecrosis of the jaw over 3 years compared with those who do not receive such treatment. Future studies will further contribute to our understanding of the bisphosphonate risk profile, thereby allowing patients and physicians to more rigorously assess the risk-benefit ratio of this treatment across different clinical scenarios.

  2. Osteonecrosis of the Jaw in Older Osteoporosis Patients Treated with Intravenous Bisphosphonates

    PubMed Central

    Baillargeon, Jacques; Kuo, Yong Fang; Lin, Yu-Li; Wilkinson, Gregg S; Goodwin, James S

    2014-01-01

    BACKGROUND Intravenous bisphosphonate therapy has been linked to osteonecrosis of the jaw among patients with cancer. Some patients with osteoporosis also receive intravenous bisphosphonates, although at lower total doses than those with cancer. OBJECTIVE To examine the risk for jaw osteonecrosis among a population-based cohort of older adults receiving intravenous bisphosphonates for the treatment of osteoporosis. METHODS Using a 5% national sample of Medicare beneficiaries, we identified 2296 patients treated with intravenous infusions of bisphosphonates for osteoporosis and other metabolic bone diseases between January 1, 2000, and December 31, 2007. We matched this cohort to 6865 bisphosphonate nonusers, at a 1:3 ratio, on age, race, sex, type of bone disease, and risk factors for osteonecrosis of the jaw. Patients were followed until December 31, 2007. The jaw toxicity outcomes included operations on the facial bones or jaw and diagnosis of inflammatory conditions of the jaw. RESULTS The absolute risk at 3 years for any jaw toxicity was 0.70 events per 100 patients using bisphosphonates and 0.30 events per 100 patients not using such drugs (2-sided log rank test, p = 0.08). In multivariable survival analyses (Cox proportional hazards regression) adjusting for potential confounders, intravenous bisphosphonate use was not significantly associated with diagnoses or procedures suggestive of osteonecrosis of the jaw (p = 0.24). CONCLUSIONS Patients with osteoporosis who are treated with intravenous bisphosphonates do not appear to have a statistically significant increase in the incidence of osteonecrosis of the jaw over 3 years compared with those who do not receive such treatment. Future studies will further contribute to our understanding of the bisphosphonate risk profile, thereby allowing patients and physicians to more rigorously assess the risk-benefit ratio of this treatment across different clinical scenarios. PMID:21954448

  3. Reduction of jaw opening (trismus) in giant cell arteritis

    PubMed Central

    Nir-Paz, R; Gross, A; Chajek-Shaul, T

    2002-01-01

    Methods: the prevalence of such symptoms in patients with GCA was evaluated by performing a retrospective analysis of all patients with GCA and polymyalgia rheumatica who were diagnosed during admission to Hadassah University Hospital. Ten patients reported previously in the literature were also evaluated. Results: Six patients out of 88 (6.8%) had complaints of reduction in jaw opening. These six patients seemed to have a much more abrupt onset of disease with shorter duration until diagnosis, higher prevalence of eye involvement (50% v 27%), and a higher rate of positive pathology (100%). Conclusions: Reduction in jaw opening in the appropriate setting may indicate the presence of GCA. This sign should not be overlooked in the presence of the claudication sign as it seems to reflect more severe GCA disease. PMID:12176811

  4. Osteonecrosis of the jaws in patients assuming bisphosphonates and sunitinib: two case reports.

    PubMed

    Agrillo, A; Nastro Siniscalchi, E; Facchini, A; Filiaci, F; Ungari, C

    2012-07-01

    Osteonecrosis of the jaw (ONJ) is an unremitting adverse outcome associated with bisphosphonate therapy, primarily intravenously administered, in patients with bone metastases from solid tumors, multiple myeloma and osteometabolic diseases. From 2003 many cases of bisphosphonates related osteonecrosis of the jaw (BRONJ) have been reported in literature. Sunititnib is a novel anticancer agent used in gastrointestinal cancers and renal cancers resistant to imatinib. Recent reports describe the onset of ONJ in patients treated with both sunitinib and bisphosponates. A case of osteonecrosis of the jaw related to sunitinib, without association of bisphosphonate (BP) medications has been recently reported. A recent hypothesis suggests that antiangiogenic drugs such as sunitinib could cause ONJ even without the association with BPs. We describe a case of two patients affected by renal carcinoma under BP and sunitinib medication who developed stage III bisphosphonates-related osteonecrosis of the jaw (BRONJ).

  5. Anti-resorptive osteonecrosis of the jaws: facts forgotten, questions answered, lessons learned.

    PubMed

    Carlson, Eric R; Schlott, Benjamin J

    2014-05-01

    Osteonecrosis of the jaws associated with bisphosphonate and other anti-resorptive medications (ARONJ) has historically been a poorly understood disease process in terms of its pathophysiology, prevention and treatment since it was originally described in 2003. In association with its original discovery 11 years ago, non-evidence based speculation of these issues have been published in the international literature and are currently being challenged. A critical analysis of cancer patients with ARONJ, for example, reveals that their osteonecrosis is nearly identical to that of cancer patients who are naive to anti-resorptive medications. In addition, osteonecrosis of the jaws is not unique to patients exposed to anti-resorptive medications, but is also seen in patients with osteomyelitis and other pathologic processes of the jaws. This article represents a review of facts forgotten, questions answered, and lessons learned in general regarding osteonecrosis of the jaws. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. The oral microbial community of gingivitis and lumpy jaw in captive macropods.

    PubMed

    Antiabong, John F; Boardman, Wayne; Moore, Robert B; Brown, Melissa H; Ball, Andrew S

    2013-12-01

    Gingivitis and lumpy jaw are diseases of polymicrobial aetiology. Although Fusobacterium necrophorum has been associated with these diseases in macropods, little is known about other organisms associated with these diseases in this animal species. PCR-DGGE analysis revealed the potential pathogens associated with gingivitis and lumpy jaw in macropods. PCR-DGGE profile comparison between the healthy and disease groups indicated a shift in the oral bacterial community structures with similarity coefficients of 48% and 35% for gingivitis and lumpy jaw respectively. Moreover, gingivitis was associated with increase in bacterial diversity (Shannon index = 2.87; PL curve = 45%) while lumpy jaw resulted in a decline in bacterial diversity (Shannon index = 2.47; PL curve = 74%). This study suggest that the establishment of gingivitis and lumpy jaw diseases follows the ecological plaque hypothesis. This forms the basis for an expanded investigation in an epidemiological scale and suggests the need for the appropriate choice of antimicrobial agent(s) and for the effective management and control of polymicrobial diseases.

  7. Disruption of programmed masticatory movements in unilateral MPTP-treated monkeys as a model of jaw movement abnormality in Parkinson's disease.

    PubMed

    Adachi, Kazunori; Kobayashi, Masayuki; Kawasaki, Toshiyuki; Yokoyama, Chihiro; Waddington, John L; Sakagami, Hiroshi; Onoe, Hirotaka; Koshikawa, Noriaki

    2012-08-01

    While motor disturbance in Parkinson's disease can affect innate, programmed processes, such as masticatory mandibular movements, the pathophysiology of such abnormalities remains unclear. This study applies digital analysis by high-speed video signal processing that tracks three dots placed around the mouth for recording masticatory movements in unilateral 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys. The system analyzes displacement, velocity and cycle duration of the topography of mandibular movement during mastication of sweet potato slices. In monkeys receiving MPTP into the right carotid artery (n = 3), positron emission tomography indicated significant reduction in the binding of (E)-N-(3-iodoprop-2-enyl)-2β-carbo[(11)C]methoxy-3β-(4-methylphenyl)nortropane ([(11)C]PE2I) to the dopamine transporter in the right caudate, putamen, nucleus accumbens and substantia nigra relative to the contralateral hemisphere. These monkeys showed hypokinesia of the left forelimbs and hindlimbs. During mastication, MPTP-treated monkeys chewed preferentially on the left side, while untreated monkeys (n = 3) showed no preference for chewing side. The amplitude of vertical opening and closing movements was reduced in MPTP-treated monkeys, with a slight but significant increase in the lateral component of mandibular movements. The velocity of all phases of horizontal mandibular movements was reduced. In consequence, duration of the occlusal phase was increased, while duration of the closing phase was decreased in MPTP-treated monkeys. These findings indicate that during masticatory movements MPTP-treated monkeys chew preferentially on the side contralateral to loss of dopamine neurons, with reduced amplitude and velocity of mandibular movements. High-speed digital movement analysis is able to define and quantify abnormalities of orofacial movement topography as a sign of parkinsonism.

  8. Updates on osteonecrosis of the jaw.

    PubMed

    Yamashita, Junro; McCauley, Laurie K; Van Poznak, Catherine

    2010-09-01

    Osteonecrosis of the jaw (ONJ) is an uncommon condition noted to occur in patients with cancer who are receiving intravenous bisphosphonates. The cause of ONJ remains unknown. The leading hypotheses addressing the mechanism of ONJ are reviewed here. The present clinical data suggest that ONJ may occur in approximately 5% of patients with metastatic bone disease. The ability to predict an individual's risk of developing ONJ remains elusive. It is likely that an altered bone microenvironment and/or host defense mechanisms effected by medications used to treat patients with metastatic bone disease contributes to the development of ONJ. Medications that significantly reduce osteoclastic activity are associated with ONJ. Preclinical models of ONJ are being developed but to establish such an intricate systemic condition in animals is challenging. The ONJ field has progressed via knowledge gained by case reports, population-based studies, and emerging animal models. Still, there are myths that need to be resolved and important clues that need to be investigated. Understanding the pathophysiology of this condition will be critical to improve patient care. Communications between oncologists, dentists, basic scientists, and patients are central to effective treatment and research for this condition.

  9. Updates on Osteonecrosis of the Jaw

    PubMed Central

    Yamashita, Junro; McCauley, Laurie; Van Poznak, Catherine

    2010-01-01

    Purpose of review Osteonecrosis of the Jaw (ONJ) in an uncommon condition noted to occur in patients with cancer receiving intravenous bisphosphonates. The etiology of ONJ remains unknown. The leading hypotheses addressing the mechanism of ONJ are reviewed here. Recent findings The present clinical data suggests that ONJ may occur in approximately 5% of patients with metastatic bone disease. The ability to predict an individual’s risk of developing ONJ remains elusive. It is likely that an altered bone microenvironment and/or host defense mechanisms effected by medications used to treat patients with metastatic bone disease contributes to the development of ONJ. Medications that significantly reduce osteoclastic activity are associated with ONJ. Preclinical models of ONJ are being developed, but to establish such an intricate systemic condition in animals is challenging. Summary The ONJ field has progressed via knowledge gained by case reports, population-based studies and emerging animal models. Still, there are myths that need to be resolved and important clues that need to be investigated. Understanding the pathophysiology of this condition will be critical to improve patient care. Communications between oncologists, dentists, basic scientists and patients are central to effective treatment and research for this condition. PMID:20657284

  10. Swiveling Lathe Jaw Concept for Holding Irregular Pieces

    NASA Technical Reports Server (NTRS)

    David, J.

    1966-01-01

    Clamp holds irregularly shaped pieces in lathe chuck without damage and eliminates excessive time in selecting optimum mounting. Interchangeable jaws ride in standard jaw slots but swivel so that the jaw face bears evenly against the workpiece regardless of contour. The jaws can be used on both engine and turret lathes.

  11. Jaw movement alters the reaction of human jaw muscles to incisor stimulation.

    PubMed

    Brinkworth, Russell S A; Türker, Kemal S

    2005-07-01

    The changes in the minimum time to consciously react (reaction time) and the order of jaw muscle recruitment to precisely controlled axial stimulation of the incisors during controlled jaw movements are not known. To this end, ten subjects were recruited to investigate the reaction time of bilateral temporalis and masseter muscles and bite force. Stimuli were delivered axially to the upper central incisors during active jaw closing and opening, and under static conditions. The results showed that the reaction time was increased an average of 35% during both jaw opening and closing movements when compared with static jaw conditions. The left temporalis was recruited approximately 10 ms before the right temporalis, whereas no significant side differences were found between the masseter muscles. The masseter muscles were recruited an average of 20 ms before the temporalis muscles during jaw closing, but no difference existed during opening. Under static conditions the reaction time in the bite force was approximately 16 ms longer than the left temporalis, but was not significantly different from the reaction time of any of the other muscles, indicating that, under the static conditions tested, the left temporalis was more often responsible for initiation of the mechanical reactions in the jaw. Because of active compensation, no force measurements were made during jaw movement. This study is a prerequisite for investigations into the modulation of reflexes during jaw movement, because a response to a stimulus commencing after the minimum reaction time may not be entirely reflex in origin.

  12. Wire-free fixation of jaw fractures.

    PubMed

    Cousin, G C S

    2009-10-01

    Stainless steel wire is often used in the management of jaw fractures to provide intraoperative or postoperative intermaxillary fixation (IMF). Wiring of the jaws is time-consuming, a second procedure is needed to remove it, and needlestick injuries occur during placement. We report on 151 consecutive patients who had wire-free fixation of jaw fractures, and outline the value of a system of plastic anchorage points applied to individual teeth in both jaws that allows for wire-free IMF when they are linked by elastics (Rapid IMF, Synthes, PA, USA). A total of 150 successive patients had wire-free fixation of 146 mandibular and 5 maxillary fractures. Ninety-eight were hand-held in occlusion, and 52 were treated using Rapid IMF. There were few complications.

  13. Zoledronate Effects on Systemic and Jaw Osteopenias in Ovariectomized Periostin-Deficient Mice

    PubMed Central

    Bonnet, Nicolas; Lesclous, Philippe; Saffar, Jean Louis; Ferrari, Serge

    2013-01-01

    Osteoporosis and periodontal disease (PD) are frequently associated in the elderly, both concurring to the loss of jaw alveolar bone and finally of teeth. Bisphosphonates improve alveolar bone loss but have also been associated with osteonecrosis of the jaw (ONJ), particularly using oncological doses of zoledronate. The effects and therapeutic margin of zoledronate on jaw bone therefore remain uncertain. We reappraised the efficacy and safety of Zoledronate (Zol) in ovariectomized (OVX) periostin (Postn)-deficient mice, a unique genetic model of systemic and jaw osteopenia. Compared to vehicle, Zol 1M (100 µg/kg/month) and Zol 1W (100 µg/kg/week) for 3 months both significantly improved femur BMD, trabecular bone volume on tissue volume (BV/TV) and cortical bone volume in both OVX Postn+/+ and Postn−/− (all p<0.01). Zol 1M and Zol 1W also improved jaw alveolar and basal BV/TV, although the highest dose (Zol 1W) was less efficient, particularly in Postn−/−. Zol decreased osteoclast number and bone formation indices, i.e. MAR, MPm/BPm and BFR, independently in Postn−/− and Postn+/+, both in the long bones and in deep jaw alveolar bone, without differences between Zol doses. Zol 1M and Zol 1W did not reactivate inflammation nor increase fibrous tissue in the bone marrow of the jaw, whereas the distance between the root and the enamel of the incisor (DRI) remained high in Postn−/− vs Postn+/+ confirming latent inflammation and lack of crestal alveolar bone. Zol 1W and Zol 1M decreased osteocyte numbers in Postn−/− and Postn+/+ mandible, and Zol 1W increased the number of empty lacunae in Postn−/−, however no areas of necrotic bone were observed. These results demonstrate that zoledronate improves jaw osteopenia and suggest that in Postn−/− mice, zoledronate is not sufficient to induce bone necrosis. PMID:23505553

  14. Zoledronate effects on systemic and jaw osteopenias in ovariectomized periostin-deficient mice.

    PubMed

    Bonnet, Nicolas; Lesclous, Philippe; Saffar, Jean Louis; Ferrari, Serge

    2013-01-01

    Osteoporosis and periodontal disease (PD) are frequently associated in the elderly, both concurring to the loss of jaw alveolar bone and finally of teeth. Bisphosphonates improve alveolar bone loss but have also been associated with osteonecrosis of the jaw (ONJ), particularly using oncological doses of zoledronate. The effects and therapeutic margin of zoledronate on jaw bone therefore remain uncertain. We reappraised the efficacy and safety of Zoledronate (Zol) in ovariectomized (OVX) periostin (Postn)-deficient mice, a unique genetic model of systemic and jaw osteopenia. Compared to vehicle, Zol 1M (100 µg/kg/month) and Zol 1W (100 µg/kg/week) for 3 months both significantly improved femur BMD, trabecular bone volume on tissue volume (BV/TV) and cortical bone volume in both OVX Postn(+/+) and Postn(-/-) (all p<0.01). Zol 1M and Zol 1W also improved jaw alveolar and basal BV/TV, although the highest dose (Zol 1W) was less efficient, particularly in Postn(-/-). Zol decreased osteoclast number and bone formation indices, i.e. MAR, MPm/BPm and BFR, independently in Postn(-/-) and Postn(+/+), both in the long bones and in deep jaw alveolar bone, without differences between Zol doses. Zol 1M and Zol 1W did not reactivate inflammation nor increase fibrous tissue in the bone marrow of the jaw, whereas the distance between the root and the enamel of the incisor (DRI) remained high in Postn(-/-) vs Postn(+/+) confirming latent inflammation and lack of crestal alveolar bone. Zol 1W and Zol 1M decreased osteocyte numbers in Postn(-/-) and Postn(+/+) mandible, and Zol 1W increased the number of empty lacunae in Postn(-/-), however no areas of necrotic bone were observed. These results demonstrate that zoledronate improves jaw osteopenia and suggest that in Postn(-/-) mice, zoledronate is not sufficient to induce bone necrosis.

  15. Potential pathophysiological mechanisms in osteonecrosis of the jaw

    PubMed Central

    Landesberg, Regina; Woo, Victoria; Cremers, Serge; Cozin, Matthew; Marolt, Darja; Vunjak-Novakovic, Gordana; Kousteni, Stavroula; Raghavan, Srikala

    2015-01-01

    Bisphosphonates are used in the treatment of hypercalcemia of malignancy, skeletal complications associated with metastastic bone disease, Paget’s disease, and osteoporosis. Osteonecrosis of the jaw (ONJ) is a recently described clinical condition that has been associated with the use of nitrogen-containing bisphosphonates. Reports describing this entity first appeared in the literature in 2003. While there have been significant numbers of case reports and a limited number of retrospective and prospective studies examining risk factors associated with ONJ, the pathophysiology of this condition remains elusive. In this review, we explore proposed mechanisms underlying ONJ development and identify potential areas for future investigation. PMID:21291478

  16. Jaw lesions associated with impacted tooth: A radiographic diagnostic guide

    PubMed Central

    Mortazavi, Hamed

    2016-01-01

    This review article aimed to introduce a category of jaw lesions associated with impacted tooth. General search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks were used to find relevant studies using keywords such as "jaw lesion", "jaw disease", "impacted tooth", and "unerupted tooth". More than 250 articles were found, of which approximately 80 were broadly relevant to the topic. We ultimately included 47 articles that were closely related to the topic of interest. When the relevant data were compiled, the following 10 lesions were identified as having a relationship with impacted tooth: dentigerous cysts, calcifying odontogenic cysts, unicystic (mural) ameloblastomas, ameloblastomas, ameloblastic fibromas, adenomatoid odontogenic tumors, keratocystic odontogenic tumors, calcifying epithelial odontogenic tumors, ameloblastic fibro-odontomas, and odontomas. When clinicians encounter a lesion associated with an impacted tooth, they should first consider these entities in the differential diagnosis. This will help dental practitioners make more accurate diagnoses and develop better treatment plans based on patients' radiographs. PMID:27672610

  17. Localized jaw enlargement in renal osteodystrophy: report of a case and review of the literature.

    PubMed

    Kalyvas, Demos; Tosios, Konstantinos I; Leventis, Minas D; Tsiklakis, Kostas; Angelopoulos, Angelos P

    2004-01-01

    Renal osteodystrophy is a common long-term complication of end-stage renal disease. Involvement of the jaws is common and radiographic alterations are often one of the earliest signs of chronic renal disease. However, marked enlargement of the jaws is a rare complication of renal osteodystrophy. A case of localized asymptomatic enlargement of the mandible in a 38-year-old woman with chronic renal failure is presented. The clinical, radiographic, and histological findings were consistent with renal osteodystrophy. To our knowledge, this is the third case of localized mandibular enlargement of renal osteodystrophy reported in the English-language literature.

  18. Diagnosis and Staging of Medication-Related Osteonecrosis of the Jaw.

    PubMed

    Ruggiero, Salvatore L

    2015-11-01

    The relationship between osteonecrosis of the jaw and bisphosphonate therapy was initially established more than 10 years ago. Since that time our understanding of this disease process has evolved as the direct result of clinical, basic science, and animal research initiatives. Medication-related osteonecrosis of the jaw (MRONJ) is a well-known entity now known to be associated with various antiresorptive therapies and recently with antiangiogenic medications. This article reviews the recently modified diagnostic criteria for MRONJ with a focus on the clinical, histopathologic, and imaging characteristics of this disease process.

  19. Osteonecrosis of the Jaw Developed in Mice

    PubMed Central

    Park, Sil; Kanayama, Keiichi; Kaur, Kawaljit; Tseng, Han-Ching Helen; Banankhah, Sina; Quje, Davood Talebi; Sayre, James W.; Jewett, Anahid; Nishimura, Ichiro

    2015-01-01

    Osteonecrosis of the jaw (ONJ), an uncommon co-morbidity in patients treated with bisphosphonates (BP), occurs in the segment of jawbone interfacing oral mucosa. This study aimed to investigate a role of oral mucosal barrier γδ T cells in the pathogenesis of ONJ. Female C57Bl/6J (B6) mice received a bolus zoledronate intravenous injection (ZOL, 540 μg/kg), and their maxillary left first molars were extracted 1 week later. ZOL-treated mice (WT ZOL) delayed oral wound healing with patent open wounds 4 weeks after tooth extraction with characteristic oral epithelial hyperplasia. γδ T cells appeared within the tooth extraction site and hyperplastic epithelium in WT ZOL mice. In ZOL-treated γδ T cell null (Tcrd−/− ZOL) mice, the tooth extraction open wound progressively closed; however, histological ONJ-like lesions were identified in 75 and 60% of WT ZOL and Tcrd−/− ZOL mice, respectively. Although the bone exposure phenotype of ONJ was predominantly observed in WT ZOL mice, Tcrd−/− ZOL mice developed the pustule/fistula disease phenotype. We further addressed the role of γδ T cells from human peripheral blood (h-γδ T cells). When co-cultured with ZOL-pretreated human osteoclasts in vitro, h-γδ T cells exhibited rapid expansion and robust IFN-γ secretion. When h-γδ T cells were injected into ZOL-treated immunodeficient (Rag2−/− ZOL) mice, the oral epithelial hyperplasia developed. However, Rag2−/− ZOL mice did not develop osteonecrosis. The results indicate that γδ T cells are unlikely to influence the core osteonecrosis mechanism; however, they may serve as a critical modifier contributing to the different oral mucosal disease variations of ONJ. PMID:26013832

  20. Jaw adductor muscles across lepidosaurs: a reappraisal.

    PubMed

    Daza, Juan Diego; Diogo, Rui; Johnston, Peter; Abdala, Virginia

    2011-10-01

    The exact homologies of tetrapod jaw muscles remain unresolved, and this provides a barrier for phylogenetic analysis and tracing character evolution. Here, lepidosaur jaw muscles are surveyed using direct examination of species from 23 families and published descriptions of species from 10 families. A revised nomenclature is applied according to proposed homologies with Latimeria. Among lepidosaurs, variation was found in many aspects of jaw muscle anatomy. The superficial layers mm. levator and retractor anguli oris (LAO and RAO) are present in Sphenodon but not all squamates. The external jaw adductor muscles universally present in lepidosaurs are homologous with the main adductor muscle, A2, of Latimeria and include four layers: superficialis (A2-SUP), medialis (A2-M), profundus (A2-PRO), and posterior (A2-PVM). The A2-SUP appears divided in Agamidae, Gekkota, Xantusiidae, and Varanidae. The A2-M is layered lateromedial in lizards but anteroposterior in snakes. The names pseudotemporalis (PS) and pterygomandibularis (PTM) are recommended for subdivisions of the internal adductors of reptiles and amphibians, because the homology of this muscle with the A3' and A3 ″ of Latimeria remains inconclusive. The intramandibularis of lepidosaurs and Latimeria (A-ω) are homologous. The distribution of six jaw muscle characters was found to plot more parsimoniously on phylogenies based on morphological rather than and molecular data. Character mapping indicates that Squamata presents reduction in the divisions of the A2-M, Scincoidea presents reduction or loss of LAO, and two apomorphic features are found for the Gekkota.

  1. Bisphosphonate-associated osteonecrosis of the jaw: the rheumatologist's role

    PubMed Central

    Capsoni, Franco; Longhi, Matteo; Weinstein, Roberto

    2006-01-01

    Several recent reports have described osteonecrosis of the jaws (ONJ) associated with the use of bisphosphonates. Rheumatologists treating bone diseases with bisphosphonate need, therefore, to be aware of this potential risk and plan the prophylaxis, early diagnosis and prevention of potential consequences. We review the literature on this newly described complication, with particular focus on systemic and local predisposing pathologies, preventive measures suggested before and during therapy with bisphosphonates, and the most frequent clinical presentation of the oral lesions. The expert panel recommendations for the management of care of patients who develop ONJ are summarized. PMID:17049069

  2. Soft Bodies, Hard Jaws: An Introduction to the Symposium, with Rotifers as Models of Jaw Diversity.

    PubMed

    Hochberg, Rick; Wallace, Robert L; Walsh, Elizabeth J

    2015-08-01

    Jaws have evolved numerous times in the animal kingdom and they display a wide variety of structural, compositional, and functional characteristics that reflect their polyphyletic origins. Among soft-bodied invertebrates, jaws are known from annelids, chaetognaths, flatworms, gnathostomulids, micrognathozoans, mollusks, rotifers, and several ecdysozoans. Depending on the taxon, jaws may function in the capture of prey (e.g., chaetognaths and flatworms), processing of prey (e.g., gnathostomulids and onychophorans), or both (e.g., rotifers). Although structural diversity among invertebrates’ jaws is becoming better characterized with the use of electron microscopy, many details remain poorly described, including neuromuscular control, elemental composition, and physical characteristics, such as hardness and resistance to wear. Unfortunately, absence of relevant data has impeded understanding of their functional diversity and evolutionary origins. With this symposium, we bring together researchers of disparately jawed taxa to draw structural and mechanistic comparisons among species to determine their commonalities. Additionally, we show that rotifers’ jaws, which are perhaps the best-characterized jaws among invertebrates, are still enigmatic with regard to their origins and mechanics. Nevertheless, technologies such as energy dispersive X-ray spectroscopy (EDX) and 3D modeling are being used to characterize their chemical composition and to develop physical models that allow exploration of their mechanical properties, respectively. We predict that these methods can also be used to develop biomimetic and bioinspired constructs based on the full range of the complexity of jaws, and that such constructs also can be developed from other invertebrate taxa. These approaches may also shed light on common developmental and physiological processes that facilitate the evolution of invertebrates’ jaws.

  3. Breastfeeding is early functional jaw orthopedics (an introduction).

    PubMed

    Page, D C

    2001-01-01

    Breastfeeding places beneficial orthopedic forces on the jaws, similar to the forces of Functional Jaw Orthopedics--the newest form of orthodontics. To date most breastfeeding benefits have been attributed to the content of mother's milk. The true orthopedic benefits of breastfeeding, suckling, deserve more definitive attention and research. Breastfeeding is early preventive Functional Jaw Orthopedics because breastfeeding forces impact the jaws during a very rapid period of infant jaw growth. Breast suckling aids proper development of the jaws which form the gateway to the human airway. Bottle, pacifier and digit sucking deform jaws and airways. Forward forces of suckling clearly oppose the backward forces of sucking. Dentists who understand the positive impact of forward orthopedic forces on the jaws should support and advocate exclusive breastfeeding for about 6 months.

  4. Alendronate-associated osteonecrosis of the jaws: A review of the main topics

    PubMed Central

    Paiva-Fonseca, Felipe; Santos-Silva, Alan R.; Della-Coletta, Ricardo; Vargas, Pablo A.

    2014-01-01

    Bisphosphonates is a group of inorganic pyrophosphates analogues that suppress bone resorption by inducing osteoclast inactivation, being frequently used for management of diseases affecting bone metabolism, bone metastases and bone tumors. However, since 2003 many cases describing the presence of necrotic bone exposures in the jaws have been described in patients receiving these drugs, what represent a significant complication of bisphosphonates treatment. The overall incidence of bisphosphonate-related osteonecrosis of the jaws is low, ranging from 0.7% to 12%, mainly observed in those patients receiving intravenously treatment. Osteonecrosis of the jaws associated to oral bisphosphonate, particularly alendronate, has also been reported by a number of authors. Considering that alendronate is one of the most used drugs worldwide, specially for treatment of osteoporosis, a better understanding of osteonecrosis of the jaws related to its use and how to manage these patients is extremely important. Therefore, in the current manuscript the authors aim to review the most important topics related to this pathological presentation. Key words:Bisphosphonates, alendronate, bisphosphonate-related osteonecrosis of the jaws, osteonecrosis. PMID:23986020

  5. Self-aligning fixture used in lathe chuck jaw refacing

    NASA Technical Reports Server (NTRS)

    Linn, C. C.

    1965-01-01

    Self-aligning tool positions and rigidly holds lathe chuck jaws for refacing and truing of the clamping surface. The jaws clamp the fixture in the manner of clamping a workpiece. The fixture can be modified to accommodate four-jawed checks.

  6. "Lumpy jaw" in exotic hoof stock: a histopathologic interpretation with a treatment proposal.

    PubMed

    Fagan, David A; Oosterhuis, James E; Benirschke, Kurt

    2005-03-01

    "Lumpy jaw" of artiodactyls and macropods, although often considered a manifestation of actinomycosis, is actually an osteomyelitis, perhaps commencing with a dental root abscess or trauma to the jaw. Anaerobes may be cultured from the lesions, and vegetable matter may be impacted in them. It is a chronic disease and difficult to treat. Successful treatment may include draining the abscess, cleaning the cavity with saline and antibiotics, flushing with a combination of hydrogen peroxide-sodium hypochlorite and Betadine, and apicoectomy and endodontic filling when active inflammation has subsided.

  7. An Unusual Case of Osteonecrosis of Jaw associated with Dengue fever and Periodontitis.

    PubMed

    Indurkar, Maya S; Sethi, Rohan

    2015-02-01

    Osteonecrosis is a disorder occurring rarely in the jaw. Dengue fever is a common mosquito-borne disease prevalent in many countries including India. The following report presents an interesting case of maxillary osteonecrosis in a middle aged male with history of dengue infection. We also diagnosed symptoms of chronic periodontitis in the patient, which may have potentiated the necrosis. This case report will describe a novel clinical presentation and management of osteonecrosis of jaw (ONJ) of unknown origin and a possible pathogenesis explaining the association of ONJ with dengue fever and periodontitis. This article is protected by copyright. All rights reserved.

  8. A novel gene mutation in PANK2 in a patient with severe jaw-opening dystonia.

    PubMed

    Yapici, Zuhal; Akcakaya, Nihan Hande; Tekturk, Pinar; Iseri, Sibel Aylin Ugur; Ozbek, Ugur

    2016-09-01

    Pantothenate kinase-associated neurodegeneration (PKAN) is a rare neurodegenerative condition. Major clinical features include progressive dystonia, pigmentary retinopathy, spasticity, and cognitive decline. The typical MRI sign of the disease, known as "eye-of-the-tiger", is what makes differential diagnosis possible. We here describe a 16-year-old male patient with PKAN presenting with severe and sustained jaw-opening dystonia which may be due to heterogeneous etiologies showing poor response to treatment. Herein, long-term follow-up and genetic results of a PKAN case who experienced severe jaw-opening dystonia are presented and discussed.

  9. The clinical value of X-ray images of the teeth and jaws

    NASA Astrophysics Data System (ADS)

    Brocklebank, Laetitia

    2003-08-01

    X-ray images of the teeth and jaws are required for a variety of diagnostic purposes to supplement a clinical examination, and are invaluable for providing pictorial information about the structures that cannot be examined with direct vision. They can be acquired using traditional film systems which produce analogue images, or using a variety of alternative image receptors which result in a digital image. Irrespective of the method of image acquisition they are utilised by the dental surgeon in order to benefit their patients' management. Numerous disease processes can affect the teeth and jaws, in addition to a range of developmental abnormalities. These can be classified according to a radiological sieve, which also includes artefactual and iatrogenic features. The key components of the classification are: developmental, inflammatory, traumatic, cystic, neoplastic, osteodystrophies and systemic disorders. This paper will utilise examples of radiographic images of patients to illustrate components of this classification which are unique to the teeth and jaws.

  10. Biomechanical analysis of jaw-closing movements.

    PubMed

    Koolstra, J H; van Eijden, T M

    1995-09-01

    This study concerns the complex interaction between active muscle forces and passive guiding structures during jaw-closing movements. It is generally accepted that the ligaments of the joint play a major role in condylar guidance during these movements. While these ligaments permit a wide range of motions, it was assumed that they are not primarily involved in force transmission in the joints. Therefore, it was hypothesized that muscle forces and movement constraints caused by the articular surfaces imply a necessary and sufficient condition to generate ordinary jaw-closing movements. This hypothesis was tested by biomechanical analysis. A dynamic six-degrees-of-freedom mathematical model of the human masticatory system has been developed for qualitative analysis of the contributions of the different masticatory muscles to jaw-closing movements, it was found that the normally observed movement, which includes a swing-slide condylar movement along the articular eminence, can be generated by various separate pairs of masticatory muscles, among which the different parts of the masseter as well as the medial pterygoid muscle appeared to be the most suitable to complete this action. The results seem to be in contrast to the general opinion that a muscle with a forward-directed force component may not be suitable for generating jaw movements in which the condyle moves backward. The results can be explained, however, by biomechanical analysis which includes not only muscle and joint forces as used in standard textbooks of anatomy, but also the torques generated by these forces.

  11. Additively manufactured sub-periosteal jaw implants.

    PubMed

    Mommaerts, M Y

    2017-02-28

    Severe bone atrophy jeopardizes the success of endosseous implants. This technical note aims to present the innovative concept of additively manufactured sub-periosteal jaw implants (AMSJIs). Digital datasets of the patient's jaws and wax trial in occlusion are used to segment the bone and dental arches, for the design of a sub-periosteal frame and abutments in the optimal location related to the dental arch and for the design of the suprastructure. The implants and suprastructure are three-dimensionally (3D) printed in titanium alloy. The provisional denture is 3D-printed in polymer. AMSJIs offer an alternative approach for patients with extreme jaw bone atrophy. This report refers to the use of this technique for full maxillary rehabilitation, but partial defects in either jaw and extended post-resection defects may also be approached using the same technique. This customized, prosthesis-driven reverse-engineering approach avoids bone grafting and provides immediate functional restoration with one surgical session.

  12. Successful surgical management of osteonecrosis of the jaw due to RANK-ligand inhibitor treatment using fluorescence guided bone resection.

    PubMed

    Otto, Sven; Baumann, Sebastian; Ehrenfeld, Michael; Pautke, Christoph

    2013-10-01

    Osteonecrosis of the jaw has recently been described in patients receiving subcutaneous administration of RANKL-inhibitors (denosumab). However, due to promising study results, more patients will receive denosumab in order to avoid skeletal complications due to metastatic bone disease and osteoporosis. Therefore, this has the potential to become a comparable challenge to the bisphosphonate induced jaw necrosis in the area of Oral and Maxillofacial Surgery. Indeed, so far no convincing surgical technique has been described to overcome the non-healing mucosal lesions with exposed bone due to RANKL-inhibitor therapy. In this technical note, we report two successful cases of surgical treatment of jaw-bone necrosis under RANKL-inhibitor treatment using fluorescence guided bone resection. In conclusion, the technique is suggested as treatment option for this entity of osteonecrosis of the jaw.

  13. Effects of eccentric jaw exercise on temporal summation in jaw-closing muscles of healthy subjects.

    PubMed

    Torisu, Tetsurou; Wang, Kelun; Svensson, Peter; De Laat, Antoon; Tanaka, Mihoko; Shimada, Akiko; Ikoma, Akiko; Murata, Hiroshi; Arendt-Nielsen, Lars

    2010-08-01

    Eccentric jaw exercises has been known to cause muscle soreness but no studies have so far examined to what extent temporal summation mechanisms within the exercised muscles are changed. The purpose of the present study was to investigate the effects of an eccentric biting exercise on the temporal summation, mechanical pressure sensitivity and jaw muscle activity. A total of 15 healthy men participated in a two-session-experiment: In one session, they performed 30 min controlled eccentric jaw exercise and the other session served as a no-exercise control. Soreness sensations at rest and during maximal biting, pressure pain thresholds (PPTs) and electromyographic (EMG) activity during maximal jaw biting were recorded before (baseline), immediately after (Post-task), and 1 day after the exercise (1-day-after). The temporal summation ratio using intra-muscular electrical stimulation of the masseter was investigated at baseline and at 1-day-after. The eccentric jaw exercise was associated with significant increases in soreness sensation and decreased PPTs at Post-task and at 1-day-after. The EMG activity and biting force did not change. The summation ratio was significantly decreased at 1-day-after in both sessions. The present findings demonstrate that eccentric jaw exercise does not induce detectable changes in temporal summation. However, the summation ratio may have clinical utility to differentiate the location of sensitization. Copyright (c) 2009 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.

  14. Architecture of the human jaw-closing and jaw-opening muscles.

    PubMed

    Van Eijden, T M; Korfage, J A; Brugman, P

    1997-07-01

    The human jaw-closing and jaw-opening muscles produce forces leading to the development of three-dimensional bite and chewing forces and to three-dimensional movements of the jaw. The length of the sarcomeres is a major determinant for both force and velocity, and the maximal work, force, and shortening range each muscle is capable of producing are proportional to the architectural parameter volume, physiological cross-sectional area, and fiber length, respectively. In addition, the mechanical role the muscles play is strongly related to their three-dimensional position and orientation in the muscle-bone-joint system. The objective of this study was to compare relevant architectural characteristics for the jaw-closing and jaw-opening muscles and to provide a set of data that can be used in biomechanical modeling of the masticatory system. In eight cadavers, sarcomere lengths, muscle masses, fiber lengths, pennation angles, and physiological cross-sectional areas were determined for the following muscles: superficial and deep masseter, anterior and posterior temporalis, anterior and posterior medial pterygoid, inferior and superior lateral pterygoid, posterior and anterior digastric, geniohyoid, posterior and anterior mylohyoid, and stylohyoid. To determine the spatial position of their action lines, the three-dimensional coordinates of the attachment sites were registered. Compared with the jaw openers, the jaw closers were characterized by shorter sarcomere lengths at the closed jaw, larger masses of contractile and tendinous tissue, larger physiological cross-sectional areas, larger pennation angles, shorter fiber lengths, shorter moment arms, and lower fiber-length-to-muscle-length ratios. In addition, architectural features differed across the muscles of the same functional group. Sarcomere length did not differ significantly among the regions of the same muscle. In contrast, in some muscles, significant intramuscular differences were found with respect to, e

  15. Bisphosphonates and osteomyelitis of the jaw: a pathogenic puzzle.

    PubMed

    Bertoldo, Francesco; Santini, Daniele; Lo Cascio, Vincenzo

    2007-12-01

    The maxillary and mandibular bones undergo high-turnover remodeling to maintain mechanical competence. Common dental or periodontal diseases can increase local bone turnover. Bisphosphonates (BPs) accumulate almost exclusively in skeletal sites that have active bone remodeling. The maxillary and mandibular bones are preferential sites for accumulation of BPs, which become buried under new layers of bone and remain biologically inactive for a long time. Surgical odontostomatological procedures create open bony wounds that heal quickly and without infection, as a result of activation of osteoclasts and subsequently osteoblasts. Once BPs are removed from the bone via activation of osteoclasts after a tooth extraction or a periodontal procedure, they induce osteoclast apoptosis. This inhibition of osteoclast bone resorption impairs bone wound healing because of decreased production of cytokines derived from the bone matrix, and the bone is exposed to the risk of osteomyelitis and necrosis. The pathogenic relationship between BPs and osteonecrosis of the jaw is unclear, but there is evidence to indicate an association between high-dose BP treatment and exposure to dental infections or oral surgical procedures. A better knowledge of the interactions between BPs and jaw and maxillary bone biology will improve clinical and therapeutic approaches.

  16. Coordination of jaw and extrinsic tongue muscle activity during rhythmic jaw movements in anesthetized rabbits.

    PubMed

    Ariyasinghe, Sajjiv; Inoue, Makoto; Yamamura, Kensuke; Harasawa, Yohji; Kurose, Masayuki; Yamada, Yoshiaki

    2004-08-06

    To clarify the jaw-closer and tongue-retractor muscle activity patterns during mastication, electromyographic activity of the styloglossus (SG) as a tongue-retractor and masseter (Mass) as a jaw-closer muscles as well as jaw-movement trajectories were recorded during cortically evoked rhythmic jaw movements (CRJMs) in anesthetized rabbits. The SG and Mass muscles were mainly active during the jaw-closing (Cl) phase. The SG activity was composed of two bursts in one masticatory cycle; one had its peak during the jaw-opening (Op) phase (SG1 burst) and the other during the Cl phase (SG2 burst). The Mass activity during the Cl phase was dominant on the working side (opposite to the stimulating side) while the SG1 and SG2 bursts were not different between the sides. When the wooden stick was inserted between the molar teeth on the working side during CRJMs, the facilitatory effects on the SG1 and SG2 bursts on both sides were noted as well as those on the Mass bursts, but the effects on the SG1 burst seemed to be weak as compared with those on the Mass and SG2 bursts. The difference in the burst timing between the sides was noted only in the SG1 burst. When the trigeminal nerves were blocked, the peak and area of the SG and Mass burst decreased during CRJMs, and the facilitatory effects of the wooden stick application on the muscles were not noted. The results suggest that the jaw and tongue muscle activities may be adjusted to chew the food and make the food bolus.

  17. Speech in ALS: Longitudinal Changes in Lips and Jaw Movements and Vowel Acoustics

    PubMed Central

    Yunusova, Yana; Green, Jordan R.; Lindstrom, Mary J.; Pattee, Gary L.; Zinman, Lorne

    2015-01-01

    Purpose The goal of this exploratory study was to investigate longitudinally the changes in facial kinematics, vowel formant frequencies, and speech intelligibility in individuals diagnosed with bulbar amyotrophic lateral sclerosis (ALS). This study was motivated by the need to understand articulatory and acoustic changes with disease progression and their subsequent effect on deterioration of speech in ALS. Method Lip and jaw movements and vowel acoustics were obtained for four individuals with bulbar ALS during four consecutive recording sessions with an average interval of three months between recordings. Participants read target words embedded into sentences at a comfortable speaking rate. Maximum vertical and horizontal mouth opening and maximum jaw displacements were obtained during corner vowels. First and second formant frequencies were measured for each vowel. Speech intelligibility and speaking rate score were obtained for each session as well. Results Transient, non-vowel-specific changes in kinematics of the jaw and lips were observed. Kinematic changes often preceded changes in vowel acoustics and speech intelligibility. Conclusions Nonlinear changes in speech kinematics should be considered in evaluation of the disease effects on jaw and lip musculature. Kinematic measures might be most suitable for early detection of changes associated with bulbar ALS. PMID:27453680

  18. Osteonecrosis of the jaws in periodontal patients with a history of bisphosphonates treatment.

    PubMed

    Ficarra, G; Beninati, F; Rubino, I; Vannucchi, A; Longo, G; Tonelli, P; Pini Prato, G

    2005-11-01

    Osteonecrosis of the jaws is being increasingly reported in patients with bone metastasis from a variety of solid tumours and disseminated multiple myeloma receiving intra-venous bisphosphonates. The signs and symptoms that may occur before the appearance of clinical evident osteonecrosis include changes in the health of periodontal tissues, non-healing mucosal ulcers, loose teeth and unexplained soft-tissue infection. A series of nine periodontally involving patients showing osteonecrosis of the jaws that appeared following the intra-venous use of bisphosphonates is reported. Nine consecutive patients with osteonecrosis of the jaws were prospectically studied. Patients' past medical histories and the drugs that they had received for their malignant disease were systematically documented. Clinical, histopathological and radiographic features and proposal for treatment modalities of osteonecrosis are also reported. Of the nine patients (six women and three men) observed, all had osteonecrosis in the mandible; two had maxillary involvement as well. All nine patients had a history of extraction of periodontally hopeless teeth preceding the onset of osteonecrosis. In two patients, the lesions also appeared in edentulous areas spontaneously. All the patients had received intra-venous bisphosphonates as treatment for their disseminated haematological neoplasms or metastatic bone disease. The duration of bisphosphonate therapy at presentation ranged from 10 to 70 months (median: 33 months). Jaw osteonecrosis appears to be associated with the intra-venous use of bisphosphonates. Dental professionals should be aware of this potentially serious complication in periodontal patients receiving long-term treatment with bisphosphonates. Copyright (c) Blackwell Munksgaard, 2005.

  19. Chemical and Radiation Associated Jaw Lesions

    PubMed Central

    Omolehinwa, Temitope T.; Akintoye, Sunday O.

    2015-01-01

    Synopsis Osteonecrosis of the jaw, at one time considered to be infrequent has now become a major public health concern not only in the United States, but throughout the world. The wide-spread use of radiotherapy for head and neck cancer as well as bone antiresorptives and antiangiogenic agents have increased the incidence of osteonecrosis. While the exact pathophysiological process of osteonecrosis is yet to be clearly defined, there has been a much higher incidence of medication-related osteonecrosis of the jaw relative to the other types of osteonecrosis. The traditional osteoradionecrosis still occurs despite better treatment planning and shielding to minimize collateral damage to bone. There are other related necrotic lesions secondary to usage of recreation drugs and the use of steroids. This chapter will give comprehensive information about these different types of bone necrosis; provide the readers with radiographic diagnostic criteria and updates on current theories on pathophysiology of osteonecrosis. PMID:26614957

  20. Radiographic apparatus for photographing entire jaws

    SciTech Connect

    Nakano, K.

    1985-01-22

    This disclosure relates to a dental radiographic apparatus for photographing the entire jaw designed to control the rotation of a rotary arm such that the film surface of a film holder mounted at one end of the rotary arm may rotate and move substantially at equal speed substantially equidistantly along the dental arch and that the X-ray beams irradiated upon the film surface from an X-ray generator mounted at the other end of the arm may fall on the dental arch at any point thereof at right angles with the arch. The apparatus makes it possible to obtain a very clear tomographic picture of a curved plane of the entire jaws, the picture being free of a double image of the teeth, partial change in enlargement ratio of the image obtained, and partial difference in the shade of the image obtained.

  1. Jaw opening in novice and experienced classically trained singers.

    PubMed

    Austin, Stephen F

    2007-01-01

    This study examined the amount of jaw opening used by two groups of singers, those with less than 4 years of training (novice) and those with more than 8 years of training (experienced) in the Western tradition of opera and art song. Movement of the jaw in the superior-inferior plane was measured with the use of a lightweight head-mounted cephalostat with a strain gauge. The subjects spoke and then sung a carrier phrase "I say b(v)p," where (v) was each of three vowels, [a], [i], and [u]. The phrase was first spoken with a natural inflection and then sung on a repeated pitch at three notes from the low, medium, and high singing voice range. There was no statistically significant difference in jaw opening between the two groups of singers. Vowel was significant for jaw opening in both groups, with [a] being produced with more jaw opening than [i] or [u]. The voicing condition was also significant for jaw opening with greater jaw opening being used as pitch increased. In general the amount of jaw opening was smallest for the low singing voice condition and greatest for the high singing voice condition. The jaw opening most typically was less in the low voice condition than in the speech condition and then increased for both the medium and high voice tasks. All but two singers used more jaw opening on the [a] vowel than the other two vowels at all voicing conditions.

  2. Osteonecrosis of jaw associated with bisphosphonate use

    PubMed Central

    Rastogi, Ashu; Rattan, Vidya; Bhadada, Sanjay Kumar

    2012-01-01

    Bisphosphonates are associated with osteonecrosis of the jaw (ONJ) that is defined as an area of exposed, nonvital bone in the maxilla or mandible persisting over 6–8 weeks. We describe a case of 55-year-old female who developed ONJ after tooth extraction and had been receiving oral ibandronate for osteoporosis. Diagnosis of ONJ was confirmed on CT scan. The patient was managed conservatively as she denied teriparatide therapy because of cost constraints. PMID:22629519

  3. Toolmarks made by lathe chuck jaws.

    PubMed

    Finkelstein, Nir; Aronson, Ayal; Tsach, Tsadok

    2017-06-01

    This paper presents a forensic method to evidentially tie a workpiece with a specific lathe. Examining using this method can prove or exclude a connection between the two. The importance of this method is mostly due to the growing trend among lawbreakers of manufacturing improvised firearm parts using machining processes. This method is based on comparing jaw impressions made by the chuck on a workpiece. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. The characters of Palaeozoic jawed vertebrates

    PubMed Central

    Brazeau, Martin D; Friedman, Matt

    2014-01-01

    Newly discovered fossils from the Silurian and Devonian periods are beginning to challenge embedded perceptions about the origin and early diversification of jawed vertebrates (gnathostomes). Nevertheless, an explicit cladistic framework for the relationships of these fossils relative to the principal crown lineages of the jawed vertebrates (osteichthyans: bony fishes and tetrapods; chondrichthyans: sharks, batoids, and chimaeras) remains elusive. We critically review the systematics and character distributions of early gnathostomes and provide a clearly stated hierarchy of synapomorphies covering the jaw-bearing stem gnathostomes and osteichthyan and chondrichthyan stem groups. We show that character lists, designed to support the monophyly of putative groups, tend to overstate their strength and lack cladistic corroboration. By contrast, synapomorphic hierarchies are more open to refutation and must explicitly confront conflicting evidence. Our proposed synapomorphy scheme is used to evaluate the status of the problematic fossil groups Acanthodii and Placodermi, and suggest profitable avenues for future research. We interpret placoderms as a paraphyletic array of stem-group gnathostomes, and suggest what we regard as two equally plausible placements of acanthodians: exclusively on the chondrichthyan stem, or distributed on both the chondrichthyan and osteichthyan stems. PMID:25750460

  5. [Osteonecrosis of the jaws by long term therapy with bisphosphonates].

    PubMed

    Piesold, Jörn-Uwe; Al-Nawas, Bilal; Grötz, Knut A

    2006-09-01

    For several decades bisphosphonates have been used to reduce skeletal related events in patients with both osteoporosis or bone metastases. Under long term application, besides the known therapy side effects, a new clinical picture has been described within the last few years. This is osteonecrosis of the jaws, which is characterized by its difficulty in treatment. Besides exposed jaw bone, the start of the disease usually lacks any symptoms. The typical clinical symptoms then are foetor ex ore, swelling, exsudation, loosening of teeth, pain or paresthesia. Later oro-antral/nasal or oro-cutaneous fistula can develop. The X-ray shows persisting tooth sockets after extractions and later cloudy radio-lucency, sequestra or fractures. The patient exposed to bisphosphonate can be grouped according to the risk for osteonecrosis: high risk patients with intravenous bisphosphonate therapy and additional chemo-, radiation or corticoid therapy--predominantly patients with a malignant underlying disease and bone metastases low risk patients with an oral bisphosphonate therapy without additional chemo-, radiation or corticoid therapy--preferably patients with non-corticoid-induced osteoporosis. Before starting a bisphosphonate therapy possible causes of infection should be treated and risk of injuries to the mucosa should be reduced according to the individual risk profile. This is supplemented by information of the patient about the risk of necrosis and the possibilities for prevention. Regular dental recall under bisphophonate therapy is emphasised for early recognition of possible problems. Prophylaxis is recommended for the prevention of periodontal infection combined with a follow up of removable denture for possible ulcera. Generally, conservative treatment measures are preferred to surgical ones. Inevitable operations are carried out non-traumatically using broad spectrum antibiotic prophylaxis until the day of suture removal (not before day 10). Long term follow up

  6. Jaw tumor in primary hyperparathyroidism is not always a brown tumor

    PubMed Central

    Ennazk, Laila; El Mghari, Ghizlane; El Ansari, Nawal

    2016-01-01

    Summary Primary hyperparthyrodism (PHPT) is a common endocrine disease. It results from an inappropriate parathyroid hormone (PTH) secretion relative to serum ionized calcium level. Clinical manifestation of severe PHPT include bone disease called osteitis fibrosa cystica which reflects an increase osteoclastic resorption and osteoblastic activity. This high bone turnover is responsible of the occurrence of osteoclastomas, also named “brown tumors” (1). Rarely, PHPT may occur in inherited forms with association to fibrous jaw tumor that are unrelated to hyperparathyroidism. In this uncommon disease: hyperparathyroidism-jaw tumor (HPT-JT) syndrome, parathyroid tumor is frequently malignant and usually associated with nonendocrine malignancies (2). We report a case of a HPT-JT syndrome to focus on the differential diagnosis with brown tumors. PMID:27252751

  7. Osteonecrosis of the jaws and bisphosphonates. Report of three cases.

    PubMed

    Pastor-Zuazaga, Daniel; Garatea-Crelgo, Joaquín; Martino-Gorbea, Raúl; Etayo-Pérez, Amaya; Sebastián-López, Cristina

    2006-01-01

    Bisphosphonates are recently acquiring increasing relevance in the treatment of several diseases. In line with the increased use of these compounds, cases of mandibular osteonecrosis, and to a lesser extent, maxillary osteonecrosis, are being reported. This necrosis is difficult to treat in patients who usually have a previously limited quality of life. A surgical performance carried out by oral and maxillofacial surgeons, stomatologists and odontologists might lead to bone exposure. A treatment based on conservation and as harmless as possible seems to be the most advisable way of acting with these patients in order to minimize the incidence and treat the complications, once the lesions have been ascertained. We report three cases treated in our service of osteonecrosis of the jaws after exodontics. This side effect should be remembered before starting any surgical treatment in these patients.

  8. Multiple jaw cysts-unveiling the Gorlin-Goltz syndrome.

    PubMed

    Manjima, S; Naik, Zameera; Keluskar, Vaishali; Bagewadi, Anjana

    2015-03-01

    Gorlin-Goltz syndrome or basal cell nevus syndrome is a comparatively rare syndrome characterized by basal cell nevi, odontogenic keratocysts, and skeletal anomalies. Diagnosis is based on the major and minor clinical and radiographic criteria. Dentist plays a major role in the diagnosis of this disease due to the oral and maxillofacial manifestations of the syndrome. In some cases, jaw cysts are diagnosed by routine radiographs advised by the dentists. Odontogenic keratocysts in such syndromic patients will be multiple and extensive and in some cases results in cortical expansion and facial disfigurement. Thorough clinical examination and investigations prompt an early confirmation of the syndrome, which is very essential to avoid morbidity associated with the syndrome. Here, we report a case of multiple odontogenic cysts in a 16-year-old patient which later was diagnosed as a case of Gorlin Goltz syndrome.

  9. Clinical and histopathological profile of primary or secondary osteosarcoma of the jaws.

    PubMed

    Angiero, Francesca; Moltrasio, Francesca; Cattoretti, Giorgio; Valente, Maria Gabriella

    2011-12-01

    Osteosarcoma of the jaw is a rare disease; we report two cases, one in which the primary osteosarcoma had occurred in the sacrum and ileum, the second at the mandible. Dissemination of osteosarcoma to other organs, especially early dissemination to the lung, is common, but metastasis to the jaw has only rarely been reported. About 10% of osteosarcomas occur in the head and neck, most in the mandible or maxilla. Clinically, both patients presented swelling, and pain at the jaw in the premolar-molar region. At radiography, extensive bone erosion and soft-tissue swelling were apparent. A biopsy was taken and a diagnosis of osteosarcoma rendered in both cases. Histological examination revealed a proliferation of atypical osteoblast-like cells with hyperchromatic nuclei and formation of scattered neoplastic osteoid tissue. Immunohistochemistry for a panel of antibodies showed strong positivity for CD99, weak positivity for S-100, but was negative for desmin, vimentin, and cytokeratins. The diagnosis for both cases was of osteogenic osteosarcoma, chondroblastic subtype. Unfortunately, both patients died, one before the planned chemotherapy regime could begin, the second during the chemotherapy course. Our report aims to highlight the importance of the diagnostic profile in formulating a diagnosis of osteosarcoma, and that this tumor, although very rare, may be primary or may metastasize to the jaws.

  10. Alendronate-associated osteonecrosis of the jaws: a review of the main topics.

    PubMed

    Paiva-Fonseca, F; Santos-Silva, A-R; Della-Coletta, R; Vargas, P-A; Lopes, M-A

    2014-03-01

    Bisphosphonates is a group of inorganic pyrophosphates analogues that suppress bone resorption by inducing osteoclast inactivation, being frequently used for management of diseases affecting bone metabolism, bone metastases and bone tumors. However, since 2003 many cases describing the presence of necrotic bone exposures in the jaws have been described in patients receiving these drugs, what represent a significant complication of bisphosphonates treatment. The overall incidence of bisphosphonate-related osteonecrosis of the jaws is low, ranging from 0.7% to 12%, mainly observed in those patients receiving intravenously treatment. Osteonecrosis of the jaws associated to oral bisphosphonate, particularly alendronate, has also been reported by a number of authors. Considering that alendronate is one of the most used drug worldwide, specially for treatment of osteoporosis, a better understanding of osteonecrosis of the jaws related to its use and how to manage these patients is extremely important. Therefore, in the current manuscript the authors aim to review the most important topics related to this pathological presentation.

  11. Dosimetric effect on pediatric conformal treatment plans using dynamic jaw with Tomotherapy HDA

    SciTech Connect

    Han, Eun Young; Kim, Dong-Wook; Zhang, Xin; Penagaricano, Jose; Liang, Xiaoying; Hardee, Matthew; Morrill, Steve; Ratanatharathorn, Vaneerat

    2015-10-01

    It is important to minimize the radiation dose delivered to healthy tissues in pediatric cancer treatment because of the risk of secondary malignancies. Tomotherapy HDA provides a dynamic jaw (DJ) delivery mode that creates a sharper penumbra at the craniocaudal ends of a target in addition to a fixed jaw (FJ) delivery mode. The purpose of this study was to evaluate its dosimetric effect on the pediatric cancer cases. We included 6 pediatric cases in this study. The dose profiles and plan statistics—target dose conformity, uniformity, organ-at-risk (OAR) mean dose, beam-on time, and integral dose—were compared for each case. Consequently, the target dose coverage and uniformity were similar for different jaw settings. The OAR dose sparing depended on its relative location to the target and disease sites. For example, in the head and neck cancer cases, the brain stem dose using DJ 2.5 was reduced by more than two-fold (2.4 Gy vs. 6.3 Gy) than that obtained with FJ 2.5. The integral dose with DJ 2.5 decreased by more than 9% compared with that with FJ 2.5. Thus, using dynamic jaw in pediatric cases could be critical to reduce a probability of a secondary malignancy.

  12. Locked jaw syndrome in dogs and cats: 37 cases (1998-2005).

    PubMed

    Gatineau, Matthieu; El-Warrak, Alexander O; Marretta, Sandra Manfra; Kamiya, D; Moreau, Maxime

    2008-03-01

    A consecutive series of cases of dogs and cats with locked jaw syndrome (inability to open or close the mouth) are reported in this study. Dogs were significantly overrepresented (84.0%) and adult dogs were more frequently affected (81.0%). Temporomandibular joint ankylosis due to fracture was the most common cause (54.0%) of locked jaw syndrome. Additional potential causes of locked jaw syndrome are masticatory muscle myositis, neoplasia, trigeminal nerve paralysis and central neurological lesions, temporomandibular joint luxation and dysplasia, osteoarthritis, retrobulbar abscess, tetanus, and severe ear disease. Treatment of locked jaw is directed towards the primary cause. It is important to treat the tonic spasm in order to minimize periarticular fibrosis. Surgical intervention is recommended for temporomandibular joint ankylosis. Masticatory muscle myositis treatment is initiated by gradually opening the mouth, with medical treatment based on immunosuppressive therapy. Fracture and masticatory muscle myositis are associated with a relatively good prognosis in regard to short-term outcome as compared to animals with central neurologic lesions or osteosarcoma which have a poor prognosis.

  13. Morphology and evolution of the jaw suspension in lamniform sharks.

    PubMed

    Wilga, C D

    2005-07-01

    The morphology of the jaw suspension and jaw protrusion mechanism in lamniform sharks is described and mapped onto a cladogram to investigate how changes in jaw suspension and protrusion have evolved. This has revealed that several evolutionary modifications in the musculoskeletal apparatus of the jaws have taken place among lamniform sharks. Galeomorph sharks (Carcharhiniformes, Lamniformes, Orectolobiformes, and Heterodontiformes) have paired ethmopalatine ligaments connecting the ethmoid process of the upper jaw to the ethmoid region of the cranium. Basal lamniform sharks also acquired a novel single palatonasal ligament connecting the symphysis of the upper jaw to the cranium mid-ventral to the nasal capsule. Sharks in the family Lamnidae subsequently lost the original paired ethmopalatine ligament while retaining the novel palatonasal ligament. Thus, basal lamniform taxa (Mitsukurina owstoni, Carcharius taurus, Alopias vulpinnis) have increased ligamentous support of the lateral region of the upper jaw while derived species (Lamnidae) have lost this lateral support but gained anterior support. In previous studies the morphology of the jaw suspension has been shown to play a major role in the mechanism of upper jaw protrusion in elasmobranchs. The preorbitalis is the primary muscle effecting upper jaw protrusion in squalean (sister group to galeomorphs) and carcharhiniform (sister group to lamniforms) sharks. The preorbitalis originates from the quadratomandibularis muscle and inserts onto the nasal capsule in squalean and carcharhiniform sharks. Carcharhiniform sharks have evolved a subdivided preorbitalis muscle with the new division inserting near the ethmoid process of the palatoquadrate (upper jaw). Alopid sharks have also independently evolved a partially subdivided preorbitalis with the new division inserting at the base of the ethmoid process and surrounding connective tissue. Lamnid sharks have retained the two preorbitalis divisions but have modified

  14. Eating with a saw for a jaw: functional morphology of the jaws and tooth-whorl in Helicoprion davisii.

    PubMed

    Ramsay, Jason B; Wilga, Cheryl D; Tapanila, Leif; Pruitt, Jesse; Pradel, Alan; Schlader, Robert; Didier, Dominique A

    2015-01-01

    The recent reexamination of a tooth-whorl fossil of Helicoprion containing intact jaws shows that the symphyseal tooth-whorl occupies the entire length of Meckel's cartilage. Here, we use the morphology of the jaws and tooth-whorl to reconstruct the jaw musculature and develop a biomechanical model of the feeding mechanism in these early Permian predators. The jaw muscles may have generated large bite-forces; however, the mechanics of the jaws and whorl suggest that Helicoprion was better equipped for feeding on soft-bodied prey. Hard shelled prey would tend to slip anteriorly from the closing jaws due to the curvature of the tooth-whorl, lack of cuspate teeth on the palatoquadrate (PQ), and resistance of the prey. When feeding on soft-bodied prey, deformation of the prey traps prey tissue between the two halves of the PQ and the whorl. The curvature of the tooth-whorl and position of the exposed teeth relative to the jaw joint results in multiple tooth functions from anterior to posterior tooth that aid in feeding on soft-bodied prey. Posterior teeth cut and push prey deeper into the oral cavity, while middle teeth pierce and cut, and anterior teeth hook and drag more of the prey into the mouth. Furthermore, the anterior-posterior edges of the teeth facilitate prey cutting with jaw closure and jaw depression. The paths traveled by each tooth during jaw depression are reminiscent of curved pathways used with slashing weaponry such as swords and knifes. Thus, the jaws and tooth-whorl may have formed a multifunctional tool for capturing, processing, and transporting prey by cyclic opening and closing of the lower jaw in a sawing fashion.

  15. New insights into dinosaur jaw muscle anatomy.

    PubMed

    Holliday, Casey M

    2009-09-01

    Jaw muscles are key components of the head and critical to testing hypotheses of soft-tissue homology, skull function, and evolution. Dinosaurs evolved an extraordinary diversity of cranial forms adapted to a variety of feeding behaviors. However, disparate evolutionary transformations in head shape and function among dinosaurs and their living relatives, birds and crocodylians, impair straightforward reconstructions of muscles, and other important cephalic soft tissues. This study presents the osteological correlates and inferred soft tissue anatomy of the jaw muscles and relevant neurovasculature in the temporal region of the dinosaur head. Hypotheses of jaw muscle homology were tested across a broad range archosaur and sauropsid taxa to more accurately infer muscle attachments in the adductor chambers of non-avian dinosaurs. Many dinosaurs likely possessed m. levator pterygoideus, a trait shared with lepidosaurs but not extant archosaurs. Several major clades of dinosaurs (e.g., Ornithopoda, Ceratopsidae, Sauropoda) eliminated the epipterygoid, thus impacting interpretations of m. pseudotemporalis profundus. M. pseudotemporalis superficialis most likely attached to the caudoventral surface of the laterosphenoid, a trait shared with extant archosaurs. Although mm. adductor mandibulae externus profundus and medialis likely attached to the caudal half of the dorsotemporal fossa and coronoid process, clear osteological correlates separating the individual bellies are rare. Most dinosaur clades possess osteological correlates indicative of a pterygoideus ventralis muscle that attaches to the lateral surface of the mandible, although the muscle may have extended as far as the jugal in some taxa (e.g., hadrosaurs, tyrannosaurs). The cranial and mandibular attachments of mm adductor mandibulae externus superficialis and adductor mandibulae posterior were consistent across all taxa studied. These new data greatly increase the interpretive resolution of head anatomy in

  16. Dosimetric comparison between jaw tracking and static jaw techniques in intensity-modulated radiotherapy.

    PubMed

    Feng, Zhongsu; Wu, Hao; Zhang, Yibao; Zhang, Yunjun; Cheng, Jinsheng; Su, Xu

    2015-01-27

    To compare the dosimetric differences between jaw tracking technique (JTT) and static jaw technique (SJT) in dynamic intensity-modulated radiotherapy (d-IMRT) and assess the potential advantages of jaw tracking technique. Two techniques, jaw tracking and static jaw, were used respectively to develop the d-IMRT plans for 28 cancer patients with various lesion sites: head and neck, lungs, esophageal, abdominal, prostate, rectal and cervical. The dose volume histograms (DVH) and selected dosimetric indexes for the whole body and for organs at risk (OARs) were compared. A two dimensional ionization chamber Array Seven29 (PTW, Freiburg, Germany) and OCTAVIUS Octagonal phantom (PTW, Freiburg, Germany) were used to verify all the plans. For all patients, the treatment plans using both techniques met the clinical requirements. The V5, V10, V20, V30, V40 (volumes receiving 5, 10, 20, 30 and 40 Gy at least, respectively), mean dose (Dmean) for the whole body and V5, V10, V20, Dmean for lungs in the JTT d-IMRT plans were significantly less than the corresponding values of the SJT d-IMRT plans (p < 0.001). The JTT d-IMRT plans deposited lower maximum dose (Dmax) to the lens, eyes, brainstem, spinal cord, and right optic nerve, the doses reductions for these OARs ranged from 2.2% to 28.6%. The JTT d-IMRT plans deposited significantly lower Dmean to various OARs (all p values < 0.05), the mean doses reductions for these OARs ranged from 1.1% to 31.0%, and the value reductions depend on the volume and the location of the OARs. The γ evaluation method showed an excellent agreement between calculation and measurement for all techniques with criteria of 3%/3 mm. Both jaw tracking and static jaw d-IMRT plans can achieve comparable target dose coverage. JTT displays superior OARs sparing than SJT plans. These results are of clinical importance, especially for the patients with large and complex targets but close to some highly radio-sensitive organs to spare, and for patients

  17. Thermal resilient multiple jaw braze fixture

    DOEpatents

    Ney, Robert; Perrone, Alex J.

    1995-07-11

    A braze fixture has side walls forming a cavity with an opening to receive a stack of parts to be brazed. Sidewalls of the housing have a plurality of bearing receiving openings into which bearing rods or jaws are inserted to align the stacked elements of the workpiece. The housing can also have view ports to allow a visual check of the alignment. Straps or wires around the fixture are selected to have thermal characteristics similar to the thermal characteristics of the workpiece undergoing brazing. The straps or wires make physical contact with the bearing rods thereby causing bearing rods to maintain the workpiece in proper alignment throughout the entire brazing cycle.

  18. ANN-Models for Jaw-Research

    DTIC Science & Technology

    2007-11-02

    Recently [5], the Peck-Langenbach-Hannam ( PLH ) dynamic model has been developed at U.B.C for the human jaw. It is based on published musculoskele- tal...of Abstract UU Number of Pages 4 Table 1: 3 sets from a 59–set of steady–state measurements of T(m;i) from the PLH simulator. m Set i=1 Set i=2 Set...Training sets can be obtained from the PLH model. The training sets will have special interest be- cause we want the network to generalize by predicting near

  19. 21 CFR 872.2060 - Jaw tracking device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., while at rest and during jaw movement. (2) Classification. Class I (general controls). The device is... the diagnosis of temporomandibular joint disorders and associated orofacial pain is a nonpowered or... maxilla, while at rest and during jaw movement. The device records, displays, and stores information...

  20. 21 CFR 872.2060 - Jaw tracking device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., while at rest and during jaw movement. (2) Classification. Class I (general controls). The device is... the diagnosis of temporomandibular joint disorders and associated orofacial pain is a nonpowered or... maxilla, while at rest and during jaw movement. The device records, displays, and stores information...

  1. Jaw morphology and fighting forces in stag beetles.

    PubMed

    Goyens, Jana; Dirckx, Joris; Aerts, Peter

    2016-09-15

    The jaws of different species of stag beetles show a large variety of shapes and sizes. The male jaws are used as weapons in fights, and they may exert a very forceful bite in some species. We investigated in 16 species whether and how the forcefulness of their bite is reflected in their jaw morphology. We found a large range of maximal muscle forces (1.8-33 N; factor of 18). Species investing in large bite muscles also have disproportionately large jaw volumes. They use this additional jaw volume to elongate their jaws, increasing their chances of winning in battles. The fact that this also decreases the mechanical advantage is largely compensated for by elongated in-levers. As a result, high muscle forces are correlated with elevated bite forces (0.27-7.6 N; factor of 28). Despite the large difference in the forcefulness of their bite, all investigated species experience similar Von Mises stresses in their jaws while biting (29-114 MPa; factor of 4.0; calculated with finite element simulations). Hence, stag beetles have successfully adapted their jaw anatomy according to their bite force in fights.

  2. Jaw muscles of New World squirrels.

    PubMed

    Ball, S S; Roth, V L

    1995-06-01

    The jaw, suprahyoid, and extrinsic tongue muscles are described for eight species of New World squirrels, spanning more than an order of magnitude in body mass. Anatomical differences are discussed in the light of body size, natural history, and phylogeny. The relative sizes of different muscles, their orientations, and the shapes and positions of their areas of attachment vary but show few trends in relation to body size. The anatomical differences are likewise not readily explained by the mechanical requirements of the animals' diets, which are similar. The most marked anatomical differences occur in Sciurillus (the pygmy tree squirrel), as well as those genera--Glaucomys (the flying squirrel) and Tamias (the chipmunk)--that are taxonomically most distinct from the tree squirrels. Sciurillus is noteworthy for its unusually small temporalis and an anterior deep masseter that is oriented to assist in retraction of the jaw. Tamias has a more vertically oriented temporalis and greater inclination in the anterior masseter muscles than the other squirrels, features that may be associated with its large diastema and relatively posteriorly situated cheek teeth, which in turn may relate to its having cheek pouches. Our results form a valuable database of information to be used in further studies of functional morphology and phylogeny.

  3. Osteonecrosis of the jaws in patients treated with intravenous bisphosphonates (BRONJ): A concise update.

    PubMed

    Bagan, Jose; Scully, Crispian; Sabater, Vicente; Jimenez, Yolanda

    2009-07-01

    Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is a severe complication seen most frequently in patients on intravenous bisphosphonates treatment for malignant diseases. High potency bisphosphonates are generally implicated and risk factors also include dental extractions. Prevention is of paramount importance. Management is controversial but there is little evidence basis and the consensus is to be conservative. Recent advances in this area are summarised in this concise review.

  4. Biochemical and mechanical characterization of Nereis worm jaws

    NASA Astrophysics Data System (ADS)

    Broomell, Christopher C.

    The ultimate goal of biomimetics is to elucidate the design principles governing performance in biological materials and apply them to engineering systems. Successful transfer of these principles will require a thorough understanding of the complex interplay between molecular composition, organization and mechanical properties of the material. This dissertation describes the mechanical and biochemical characterization of jaws from the marine polychaete Nereis virens. Nereid jaws possess remarkable mechanical properties considering their predominantly organic composition. Hardness and stiffness are comparable to human dentin. However, in stark contrast to dentin, in Nereis these properties are achieved without mineralization. The role of metal ions in jaw sclerotization is addressed. In the pristine state, Zn ions are concentrated at the tip and toothed-edge of the jaw and are critical for hardness and modulus; both properties are reduced by ˜70% following Zn removal by treatment with EDTA. Furthermore, metal content in the jaw can be manipulated by soaking Zn-depleted samples in metal solutions; the comparative effects of treatment with alternative transition metals under both dry and hydrated conditions are described. The molecular composition of the jaw is also addressed. Protein comprises ˜90% of the jaw mass; amino acid analysis indicates that histidine is increased in the hardened, Zn-rich tip. The major protein component in Nereid jaw extracts is purified and characterized by partial peptide mapping and isolation of a partial clone from a jaw pulp cDNA library. Nvjp-1 is a 38 kDa glycine- histidine-rich protein and is believed to be the principle structural protein in the hardened jaw tip. The effects of selected environmental factors on Nvjp-1 structure and assembly are described. Transition from low to high pH is accompanied by changes in secondary structure and a significant molecular elongation. Furthermore, exposure to transition metals, notably Zn and

  5. Changes in jaw-jerk on different levels of jaw closure and teeth-clenching in humans.

    PubMed

    Fukuyama, E; Fujita, Y; Soma, K

    2000-11-01

    We investigated how the jaw-jerk in the human masseter muscle is modulated in relation to the level of jaw closure (JC) and teeth clenching. Electromyographic (EMG) activity was recorded with surface electrodes. Background EMG activity of the masseter muscle was kept at three low teeth clenching levels with visual feedback. The level of JC was changed in six steps along the habitual path of closure relative to the mean maximal jaw opening during gum chewing by inserting a bite block between the upper and lower molars. The jaw-jerk was evoked by applying mechanical stimulation of about 20 N with a hammer to the bite-fork placed on the lower molars on one side in each condition of combination of a level of JC with a level of teeth-clenching. At the resting condition the excitability of the jaw-jerk increased with JC, while at weak voluntary teeth clenching it then decreased and increased again as the jaw was progressively closed. It is suggested that the excitability of the jaw-jerk would increase toward the occlusal position, which in turn would contribute to smooth masticatory movements. In addition, the mode of modulation of the jaw-jerk was studied in a subject with skeletal malocclusion.

  6. Analysis of jaw movements and muscle activity during mastication with JawReports Software.

    PubMed

    John, D; Ruge, S; Kordass, B

    2011-01-01

    We are currently developing new software for simultaneous visualisation and analysis of computerized recorded masticatory function and masticatory muscle activity. With the software, motion data recorded using the Jaw Motion Analyser and EMG data on masseter muscle activity can be uploaded in order to evaluate chewing activity immediately proximal to the occlusal surfaces. The software successfully differentiated between jaw opening and closing movements and filtered out muscle activity peaks, which were graphically depicted in the respective movement trajectories. This tracking strategy made it possible to visualize the movement sectors where chewing forces were effective and to estimate the strength of these forces. In the future, this software should improve our ability to analyze and assess the development of chewing forces. Therefore, it could provide a tool for optimal planning of implant-supported or CAD/CAM restorations.

  7. Thermal resilient multiple jaw braze fixture

    DOEpatents

    Ney, R.; Perrone, A.J.

    1995-07-11

    A braze fixture has side walls forming a cavity with an opening to receive a stack of parts to be brazed. Sidewalls of the housing have a plurality of bearing receiving openings into which bearing rods or jaws are inserted to align the stacked elements of the workpiece. The housing can also have view ports to allow a visual check of the alignment. Straps or wires around the fixture are selected to have thermal characteristics similar to the thermal characteristics of the workpiece undergoing brazing. The straps or wires make physical contact with the bearing rods thereby causing bearing rods to maintain the workpiece in proper alignment throughout the entire brazing cycle. 9 figs.

  8. Biphosphonates-related osteonecrosis of the jaw: Clinical and physiopathological considerations

    PubMed Central

    Borgioli, Alberto; Viviani, Christian; Duvina, Marco; Brancato, Leila; Spinelli, Giuseppe; Brandi, Maria Luisa; Tonelli, Paolo

    2009-01-01

    Since osteonecrosis of the jaw was related to biphosphonate administration by Marx, studies showing clinical symptoms, drug and surgical therapies overwhelmed the literature. Furthermore, the literature demonstrated the correlation between chronic biphosphonate adsumption and osteonecrosis of the jaw onset. Nitrogen-containing biphosphonates are widely used for the management of metastatic cancer, for prevention and treatment of osteoporosis, for the treatment of Paget's disease, and for the management of acute hypercalcemia. According to our experience, the treatment of BRON-J's lesions is difficult and prolonged. For this reason, in order to avoid these complications it is mandatory to perform a risk staging in patients who must undergo biphosphonate administration. When pharmacologic treatments with antibiotics and local antiseptics are not able to control the development of BRON-J's complications, the clinicians should perform radical surgical treatments such as the resection of the bone involved. PMID:19436626

  9. Expression of Msx-1 is suppressed in bisphosphonate associated osteonecrosis related jaw tissue-etiopathology considerations respecting jaw developmental biology-related unique features

    PubMed Central

    2010-01-01

    Background Bone-destructive disease treatments include bisphosphonates and antibodies against the osteoclast differentiator, RANKL (aRANKL); however, osteonecrosis of the jaw (ONJ) is a frequent side-effect. Current models fail to explain the restriction of bisphosphonate (BP)-related and denosumab (anti-RANKL antibody)-related ONJ to jaws. Msx-1 is exclusively expressed in craniofacial structures and pivotal to cranial neural crest (CNC)-derived periodontal tissue remodeling. We hypothesised that Msx-1 expression might be impaired in bisphosphonate-related ONJ. The study aim was to elucidate Msx-1 and RANKL-associated signal transduction (BMP-2/4, RANKL) in ONJ-altered and healthy periodontal tissue. Methods Twenty ONJ and twenty non-BP exposed periodontal samples were processed for RT-PCR and immunohistochemistry. An automated staining-based alkaline phosphatase-anti-alkaline phosphatase method was used to measure the stained cells:total cell-number ratio (labelling index, Bonferroni adjustment). Real-time RT-PCR was performed on ONJ-affected and healthy jaw periodontal samples (n = 20 each) to quantitatively compare Msx-1, BMP-2, RANKL, and GAPDH mRNA levels. Results Semi-quantitative assessment of the ratio of stained cells showed decreased Msx-1 and RANKL and increased BMP-2/4 (all p < 0.05) expression in ONJ-adjacent periodontal tissue. ONJ tissue also exhibited decreased relative gene expression for Msx-1 (p < 0.03) and RANKL (p < 0.03) and increased BMP-2/4 expression (p < 0.02) compared to control. Conclusions These results explain the sclerotic and osteopetrotic changes of periodontal tissue following BP application and substantiate clinical findings of BP-related impaired remodeling specific to periodontal tissue. RANKL suppression substantiated the clinical finding of impaired bone remodelling in BP- and aRANKL-induced ONJ-affected bone structures. Msx-1 suppression in ONJ-adjacent periodontal tissue suggested a bisphosphonate-related impairment in

  10. Expression of Msx-1 is suppressed in bisphosphonate associated osteonecrosis related jaw tissue-etiopathology considerations respecting jaw developmental biology-related unique features.

    PubMed

    Wehrhan, Falk; Hyckel, Peter; Ries, Jutta; Stockmann, Phillip; Nkenke, Emeka; Schlegel, Karl A; Neukam, Friedrich W; Amann, Kerstin

    2010-10-13

    Bone-destructive disease treatments include bisphosphonates and antibodies against the osteoclast differentiator, RANKL (aRANKL); however, osteonecrosis of the jaw (ONJ) is a frequent side-effect. Current models fail to explain the restriction of bisphosphonate (BP)-related and denosumab (anti-RANKL antibody)-related ONJ to jaws. Msx-1 is exclusively expressed in craniofacial structures and pivotal to cranial neural crest (CNC)-derived periodontal tissue remodeling. We hypothesised that Msx-1 expression might be impaired in bisphosphonate-related ONJ. The study aim was to elucidate Msx-1 and RANKL-associated signal transduction (BMP-2/4, RANKL) in ONJ-altered and healthy periodontal tissue. Twenty ONJ and twenty non-BP exposed periodontal samples were processed for RT-PCR and immunohistochemistry. An automated staining-based alkaline phosphatase-anti-alkaline phosphatase method was used to measure the stained cells:total cell-number ratio (labelling index, Bonferroni adjustment). Real-time RT-PCR was performed on ONJ-affected and healthy jaw periodontal samples (n = 20 each) to quantitatively compare Msx-1, BMP-2, RANKL, and GAPDH mRNA levels. Semi-quantitative assessment of the ratio of stained cells showed decreased Msx-1 and RANKL and increased BMP-2/4 (all p < 0.05) expression in ONJ-adjacent periodontal tissue. ONJ tissue also exhibited decreased relative gene expression for Msx-1 (p < 0.03) and RANKL (p < 0.03) and increased BMP-2/4 expression (p < 0.02) compared to control. These results explain the sclerotic and osteopetrotic changes of periodontal tissue following BP application and substantiate clinical findings of BP-related impaired remodeling specific to periodontal tissue. RANKL suppression substantiated the clinical finding of impaired bone remodelling in BP- and aRANKL-induced ONJ-affected bone structures. Msx-1 suppression in ONJ-adjacent periodontal tissue suggested a bisphosphonate-related impairment in cellular differentiation that occurred

  11. Jaw-muscle architecture and mandibular morphology influence relative maximum jaw gapes in the sexually dimorphic Macaca fascicularis.

    PubMed

    Terhune, Claire E; Hylander, William L; Vinyard, Christopher J; Taylor, Andrea B

    2015-05-01

    Maximum jaw gape is a performance variable related to feeding and non-feeding oral behaviors, such as canine gape displays, and is influenced by several factors including jaw-muscle fiber architecture, muscle position on the skull, and jaw morphology. Maximum gape, jaw length, and canine height are strongly correlated across catarrhine primates, but relationships between gape and other aspects of masticatory apparatus morphology are less clear. We examine the effects of jaw-adductor fiber architecture, jaw-muscle leverage, and jaw form on gape in an intraspecific sample of sexually dimorphic crab-eating macaques (Macaca fascicularis). As M. fascicularis males have relatively larger maximum gapes than females, we predict that males will have muscle and jaw morphologies that facilitate large gape, but these morphologies may come at some expense to bite force. Male crab-eating macaques have relatively longer jaw-muscle fibers, masseters with decreased leverage, and temporomandibular joint morphologies that facilitate the production of wide gapes. Because relative canine height is correlated with maximum gape in catarrhines, and males have relatively longer canines than females, these results support the hypothesis that male M. fascicularis have experienced selection to increase maximum gape. The sexes do not differ in relative masseter physiologic cross-sectional area (PCSA), but males compensate for a potential trade-off between muscle excursion versus muscle force with increased temporalis weight and PCSA. This musculoskeletal configuration is likely functionally significant for behaviors involving aggressive canine biting and displays in male M. fascicularis and provides additional evidence supporting the multifactorial nature of the catarrhine masticatory apparatus. Our results have implications for the evolution of craniofacial morphology in catarrhine primates and reinforce the importance of evaluating additional factors other than feeding behavior and diet

  12. Motor control of jaw muscles in chewing and in isometric biting with graded narrowing of jaw gape.

    PubMed

    Pröschel, P A; Jamal, T; Morneburg, T R

    2008-10-01

    When a certain bite force is applied during unilateral chewing, the combination of jaw elevator muscle activities is different than when a comparable force is applied in unilateral isometric biting, e.g. on a force transducer. Masticatory peak force is generated in a nearly isometric phase of the chewing cycle, with a jaw gape of about 1 mm. In contrast, peak force in isometric biting on force measuring equipment usually induces jaw gapes of 6 mm or even more. Therefore, we tested the hypothesis that the jaw gape influences relative activation of elevator muscles in unilateral isometric biting. We further examined whether such influence could explain the different activity combinations of chewing and isometric biting. In thirty asymptomatic males, masseter and temporalis activities were recorded during intermittent isometric biting with jaw gapes of 6, 5, 3, 2 and 1 mm and during unilateral chewing. Activity combinations were described by working/balancing ratios and by temporalis/masseter ratios. With decreasing jaw gape the working/balancing ratio of the posterior temporalis decreased (P < 0.002) while that of the masseter increased (P < 0.001). Likewise, the temporalis/masseter ratio on the balancing side increased (P < 0.001). With decreasing jaw gape, activity ratios of isometric biting approached ratios of chewing. We conclude that: (i) relative jaw muscle activation in isometric biting depends on the jaw gape, (ii) relative muscle activation in chewing resembles relative activation of isometric biting with a small 'chewing-like' gape. This suggests that characteristic activity combinations in chewing are mainly a result of the approximately isometric contraction during the slow closing phase of the chewing cycle.

  13. 33. DETAIL VIEW LOOKING DOWN AT THE BLAKE JAW CRUSHER. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. DETAIL VIEW LOOKING DOWN AT THE BLAKE JAW CRUSHER. NOT THE IDLER PULLEYS AND THE PULLEYS AD SHAFT OF THE POWER SYSTEM OVERHEAD. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  14. Dependence of jaw opening on pitch and vowel in singers.

    PubMed

    Sundberg, J; Skoog, J

    1997-09-01

    In singing, F0 sometimes is much higher than the typical frequency value of F1. According to previous investigations, sopranos raise F1 to a frequency near F0 by widening the jaw opening in such cases. In the present study, the jaw opening was measured in 10 professional singers of different categorizations whose task was to sing an ascending two-octave scale on different vowels. Their normal F1 values for these vowels were determined at a low F0. Only for the vowels /a/ and /a/ did the singers widen the jaw opening when F0 approached the F1 value measured at a low pitch. For the other vowels, jaw opening was widened, beginning at a higher F0. It is assumed that for these vowels the singers used other articulatory means to increase F1.

  15. [Relationship between osteonecrosis of the jaw and bisphosphonate treatment].

    PubMed

    Badel, Tomislav; Keros, Jadranka; Krapac, Ladislav; Pavicin, Ivana Savić

    2010-09-01

    Bisphosphonate treatment and its aetiopathogenic association with aseptic osteonecrosis of the jaw is one of the more prominent public health issues today. The aim of this review is to see into the mechanisms of bisphosphonate effects on bones described in literature (anti-osteoclastic activity, cytotoxicity, antiangiogenesis, genetic factors, and imbalance between osteoclasts and osteoblasts). Bisphosphonate treatment is the dominant cause of jaw necrosis. Epidemiological data show an exclusive incidence of osteonecrosis of the jaw in patients who took one or a combination of nitrogen-containing bisphosphonates. Risk factors vary by the bisphosphonate potency (particularly risky are the highly potent pamidronate and zoledronate, which are given intravenously), dosage, duration of treatment, and the illness. Jaw necrosis is most common in oncology patients, and only 5 % in patients with osteoporosis. From a dental-medical point of view, a good oral health is important because osteonecrosis often appears after a periodontal or oral surgical procedure.

  16. Monte Carlo-based simulation of dynamic jaws tomotherapy

    SciTech Connect

    Sterpin, E.; Chen, Y.; Chen, Q.; Lu, W.; Mackie, T. R.; Vynckier, S.

    2011-09-15

    Purpose: Original TomoTherapy systems may involve a trade-off between conformity and treatment speed, the user being limited to three slice widths (1.0, 2.5, and 5.0 cm). This could be overcome by allowing the jaws to define arbitrary fields, including very small slice widths (<1 cm), which are challenging for a beam model. The aim of this work was to incorporate the dynamic jaws feature into a Monte Carlo (MC) model called TomoPen, based on the MC code PENELOPE, previously validated for the original TomoTherapy system. Methods: To keep the general structure of TomoPen and its efficiency, the simulation strategy introduces several techniques: (1) weight modifiers to account for any jaw settings using only the 5 cm phase-space file; (2) a simplified MC based model called FastStatic to compute the modifiers faster than pure MC; (3) actual simulation of dynamic jaws. Weight modifiers computed with both FastStatic and pure MC were compared. Dynamic jaws simulations were compared with the convolution/superposition (C/S) of TomoTherapy in the ''cheese'' phantom for a plan with two targets longitudinally separated by a gap of 3 cm. Optimization was performed in two modes: asymmetric jaws-constant couch speed (''running start stop,'' RSS) and symmetric jaws-variable couch speed (''symmetric running start stop,'' SRSS). Measurements with EDR2 films were also performed for RSS for the formal validation of TomoPen with dynamic jaws. Results: Weight modifiers computed with FastStatic were equivalent to pure MC within statistical uncertainties (0.5% for three standard deviations). Excellent agreement was achieved between TomoPen and C/S for both asymmetric jaw opening/constant couch speed and symmetric jaw opening/variable couch speed, with deviations well within 2%/2 mm. For RSS procedure, agreement between C/S and measurements was within 2%/2 mm for 95% of the points and 3%/3 mm for 98% of the points, where dose is greater than 30% of the prescription dose (gamma analysis

  17. Evolutionary Trends in the Jaw Adductor Mechanics of Ornithischian Dinosaurs.

    PubMed

    Nabavizadeh, Ali

    2016-03-01

    Jaw mechanics in ornithischian dinosaurs have been widely studied for well over a century. Most of these studies, however, use only one or few taxa within a given ornithischian clade as a model for feeding mechanics across the entire clade. In this study, mandibular mechanical advantages among 52 ornithischian genera spanning all subclades are calculated using 2D lever arm methods. These lever arm calculations estimate the effect of jaw shape and difference in adductor muscle line of action on relative bite forces along the jaw. Results show major instances of overlap between taxa in tooth positions at which there was highest mechanical advantage. A relatively low bite force is seen across the tooth row among thyreophorans (e.g., stegosaurs and ankylosaurs), with variation among taxa. A convergent transition occurs from a more evenly distributed bite force along the jaw in basal ornithopods and basal marginocephalians to a strong distal bite force in hadrosaurids and ceratopsids, respectively. Accordingly, adductor muscle vector angles show repeated trends from a mid-range caudodorsal orientation in basal ornithischians to a decrease in vector angles indicating more caudally oriented jaw movements in derived taxa (e.g., derived thyreophorans, basal ornithopods, lambeosaurines, pachycephalosaurs, and derived ceratopsids). Analyses of hypothetical jaw morphologies were also performed, indicating that both the coronoid process and lowered jaw joint increase moment arm length therefore increasing mechanical advantage of the jaw apparatus. Adaptive trends in craniomandibular anatomy show that ornithischians evolved more complex feeding apparatuses within different clades as well as morphological convergences between clades. © 2016 Wiley Periodicals, Inc.

  18. Estimates of loss rates of jaw tags on walleyes

    USGS Publications Warehouse

    Newman, Steven P.; Hoff, Michael H.

    1998-01-01

    The rate of jaw tag loss was evaluated for walleye Stizostedion vitreum in Escanaba Lake, Wisconsin. We estimated tag loss using two recapture methods, a creel census and fykenetting. Average annual tag loss estimates were 17.5% for fish recaptured by anglers and 27.8% for fish recaptured in fyke nets. However, fyke-net data were biased by tag loss during netting. The loss rate of jaw tags increased with time and walleye length.

  19. Jaw Dislocation as an Unusual Complication of Upper Endoscopy

    PubMed Central

    Dellon, Evan S.; Steele, David

    2016-01-01

    This case report presents an unusual complication of upper endoscopy, resulting in jaw dislocation. Temporomandibular joint dislocation is commonly reported in association with anesthesia and intubation, but it is not widely recognized as a complication of gastrointestinal endoscopy. This report also reviews the current literature regarding this complication and discusses the potential causes of dislocation, differential diagnoses for jaw pain following endoscopy, and recommendations for prevention. PMID:27403117

  20. Caecilian jaw-closing mechanics: integrating two muscle systems.

    PubMed

    Kleinteich, Thomas; Haas, Alexander; Summers, Adam P

    2008-12-06

    Caecilians (Lissamphibia: Gymnophiona) are unique among vertebrates in having two sets of jaw-closing muscles, one on either side of the jaw joint. Using data from high-resolution X-ray radiation computed tomography scans, we modelled the effect of these two muscle groups (mm. levatores mandibulae and m. interhyoideus posterior) on bite force over a range of gape angles, employing a simplified lever arm mechanism that takes into account muscle cross-sectional area and fibre angle. Measurements of lever arm lengths, muscle fibre orientations and physiological cross-sectional area of cranial muscles were available from three caecilian species: Ichthyophis cf. kohtaoensis; Siphonops annulatus; and Typhlonectes natans. The maximal gape of caecilians is restricted by a critical gape angle above which the mm. levatores mandibulae will open the jaw and destabilize the mandibular joint. The presence of destabilizing forces in the caecilian jaw mechanism may be compensated for by a mandibular joint in that the fossa is wrapped around the condyle to resist dislocation. The caecilian skull is streptostylic; the quadrate-squamosal complex moves with respect to the rest of the skull. This increases the leverage of the jaw-closing muscles. We also demonstrate that the unusual jaw joint requires streptostyly because there is a dorsolateral movement of the quadrate-squamosal complex when the jaw closes. The combination of the two jaw-closing systems results in high bite forces over a wide range of gape angles, an important advantage for generalist feeders such as caecilians. The relative sizes and leverage mechanics of the two closing systems allow one to exert more force when the other has a poor mechanical advantage. This effect is seen in all three species we examined. In the aquatic T. natans, with its less well-roofed skull, there is a larger contribution of the mm. levatores mandibulae to total bite force than in the terrestrial I. cf. kohtaoensis and S. annulatus.

  1. Primary Ewing Family of Tumors of the Jaw has a better Prognosis compared to Tumors of Extragnathic sites

    PubMed Central

    Owosho, Adepitan A.; Ko, Eugene; Rosenberg, Haley I.; Yom, SaeHee K.; Antonescu, Cristina R.; Huryn, Joseph M.; Estilo, Cherry L.

    2016-01-01

    Purpose Primary Ewing sarcoma of the jaw is rare. The aim of this study was to describe new cases of primary Ewing sarcoma of the jaw and investigate reported prognostic factors of Ewing sarcoma in this series and treatment outcome. Materials and Methods Six patients with primary Ewing sarcoma of the jaw were treated at the Memorial Sloan Kettering Cancer Center (MSKCC) from 1992 through 2013. Clinical data, pathology reports, treatment prescribed, treatment regimens, outcome, and follow-up information were reviewed. Results Five of 6 patients were female and 5 cases were in the mandible. No patient presented with metastatic disease at diagnosis. All cases were positive for CD99, and 3 patients with genetic confirmation were positive for EWS-FLI1 fusion or EWSR1 gene rearrangement. All patients received induction multiagent chemotherapy and surgical resection and 2 patients received adjuvant radiotherapy. Total (grade IV) or nearly total (grade III) tumor necrosis in 3 of 5 patients (60%) assessed for histologic response to chemotherapy indicated intense sensitivity. All patients were alive and free of disease, with no history of local recurrence, at a median follow-up period of 6.5 years. Conclusion Patients with primary Ewing sarcoma of the jaw have a good prognosis and metastasis is an uncommon occurrence at initial presentation. PMID:26679553

  2. Jaw osteonecrosis management around a dental implant inserted 2 years before starting treatment with zoledronic acid

    PubMed Central

    Marín-Fernández, Ana-Belén; García Medina, Blas; Aguilar-Salvatierra, Antonio; Jiménez-Burkhardt, Alberto

    2015-01-01

    Bisphosphonates (BP) are a type of drug known to inhibit bone resorption through complex interventions. Their primary mechanism of action is aimed at the cellular level, inhibiting osteoclast activity and so bone resorption. BPs are widely used, with many patients receiving continuous treatment for years. But it is well known that these drugs can produce osteonecrosis of the jaw (ONJ). Zoledronic acid (ZA) is an intravenous BP used in the treatment and prophylaxis of bone disease in patients with malignant tumors with bone implication. ZA is the most potent BP in clinical development. This report describes the case of a 62-year-old woman with breast cancer antecedents which relapsed, who had received a maxillary dental implant two years before the start of therapy with zoledronic acid. She later developed osteonecrosis of the jaw (ONJ), which began in the peri-implant area, and was treated for stage 3 ONJ by sub-total maxillectomy. Key words:Bisphosphonates, zoledronic acid, osteonecrosis of the jaw, peri-implantitis, maxillectomy. PMID:26330946

  3. Radiolucent rim as a possible diagnostic aid for differentiating jaw lesions

    PubMed Central

    Mortazavi, Hamed; Rahmani, Somayeh; Jafari, Soudeh; Parvaei, Parvin

    2015-01-01

    In this study, we formulate a new proposal that complements previous classifications in order to assist dental practitioners in performing a differential diagnosis based on patients' radiographs. We used general search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks to find relevant studies by using keywords such as "jaw disease," "jaw lesions," "radiolucent rim," "radiolucent border," and "radiolucent halo." More than 200 articles were found, of which 70 were broadly relevant to the topic. We ultimately included 50 articles that were closely related to the topic of interest. When the relevant data were compiled, the following eight lesions were identified as having a radiolucent rim: periapical cemento-osseous dysplasia, focal cemento-osseous dysplasia, florid cemento-osseous dysplasia, cemento-ossifying fibroma, osteoid osteoma, osteoblastoma, odontoma, and cementoblastoma. We propose a novel subcategory, jaw lesions with a radiolucent rim, which includes eight entities. The implementation of this new category can help improve the diagnoses that dental practitioners make based on patients' radiographs. PMID:26730374

  4. Management of osteonecrosis of the jaws in patients with history of bisphosphonates therapy.

    PubMed

    Antonini, Fernando; Pereira, Cassiano Costa Silva; Parente, Eduardo Varela; Azambuja, Fabiano Goulart

    2010-11-01

    Bisphosphonates are compounds used in the treatment of various metabolic and malignant bone diseases. The relation between the use of bisphosphonates and ostenonecrosis of the jaws as an adverse effect of the drug has been intensely discussed during the last few years, and up to this moment, there is no consensus concerning an ideal treatment modality for this condition. Nevertheless, there is an agreement among researchers that the standard goal for controlling jaw osteonecrosis is to prevent it. Otherwise, the rationale for a randomized controlled trial is that current treatment has proven to be suboptimal, and no consensus has been reached yet on the best strategies to repair the exposed bone once bone necrosis is developed. This article is focused on reporting a case of moderate osteonecrosis of the upper jaw induced by bisphosphonates and discusses a possible role for surgical debridement associated to platelet-rich plasma, hyperbaric oxygen therapy, and the cessation of the bisphosphonate use in managing this type of lesion. Moreover, the dentist, the oral surgeon, and the oncologist need to work together to reach better outcomes.

  5. Bisphosphonate-related osteonecrosis of the jaws: how to manage cancer patients.

    PubMed

    Madrid, C; Bouferrache, K; Abarca, M; Jaques, B; Broome, M

    2010-06-01

    Bisphosphonate related osteonecrosis of the jaw (BRONJ) is defined as exposed necrotic bone appearing in the jaws of patients treated by systemic IV or oral BPs never irradiated in the head and neck area and that has persisted for more than 8 weeks. More than 90% of cases of osteonecrosis of the jaw have been in patients with cancer who received IV-BPs. The estimate of cumulative incidence of BRONJ in cancer patients with IV-BPs ranges from 0.8% to 18.6%. The pathogenesis of BRONJ appeared related to the potent osteoblast-inhibiting properties of BPs which act by blocking osteoclast recruitment, decreasing osteoclast activity and promoting osteoclast apoptosis. Dental extractions are the most potent local risk factor. Cancer patients wearing a denture could also be at increased risk of BRONJ. Non-healing mucosal breaches caused by dentures could be a portal for the oral flora to access bone, while the oral mucosa of patients on IV-BPs could also be defective. Whether periodontal disease is a risk factor for BRONJ remains controversial. Preventive measures are fundamental. Nevertheless, some teams have questioned its cost-effectiveness. The perceived limitations of surgical therapy of BRONJ led to the restriction of aggressive surgery to symptomatic patients with stage 3 BRONJ. The evidence-based literature on BRONJ is growing but there are still many controversial aspects. Copyright 2010 Elsevier Ltd. All rights reserved.

  6. Mitoxantrone as a contributing factor in medication-related osteonecrosis of the jaws.

    PubMed

    Bagan, J V; Bagan, L; Poveda, R; Scully, C

    2016-03-01

    Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is usually initiated by dental surgery, but is occasionally exacerbated by other antiresorptive (denosumab) and anti-angiogenic therapies, and in such cases is currently termed medication-related osteonecrosis of the jaws (MRONJ). The case of a 58-year-old female with breast cancer who developed multiple and ultimately fatal metastases despite 3 years of treatment with chemotherapeutic drugs and intravenous bisphosphonates, is presented herein. Her malignant disease worsened and she was started on mitoxantrone. She developed a severe adverse reaction to this drug soon after starting treatment. As well as diarrhoea and vomiting, she had a very aggressive gingival inflammation with multiple ulcerations in both jaws and wide areas of necrotic bone, affecting the attached gingiva, and seemingly unrelated to dental plaque. These ulcerations and the exposed necrotic bone persisted for more that 6 months, until her death. This report describes a case in which severe gingival ulcerations that occurred after mitoxantrone treatment for metastatic breast cancer were a local factor that initiated MRONJ.

  7. A Novel Mutation in a Patient with Hyperparathyroidism-Jaw Tumour Syndrome.

    PubMed

    Bellido, Virginia; Larrañaga, Ihintza; Guimón, Maite; Martinez-Conde, Rafael; Eguia, Asier; Perez de Nanclares, Gustavo; Castaño, Luis; Gaztambide, Sonia

    2016-06-01

    Hyperparathyroidism-jaw tumour syndrome (HPT-JT) is a rare variant of familial hyperparathyroidism, characterized by primary hyperparathyroidism (PHPT) due to one or multiple parathyroid adenomas, and benign tumours of the mandible and maxilla. It has an autosomal dominant pattern of inheritance, and is associated with mutations that deactivate the cell division cycle protein 73 homolog (CDC73) gene, also known as hyperparathyroidism 2 (HRPT2), located on the long arm of chromosome 1, that encodes for the tumour suppressor protein parafibromin. In the majority of cases, PHPT is the presenting symptom, but up to 30 % of HPT-JT cases initially present with an ossifying fibroma of the maxillofacial bones. HPT-JT may result in severe hypercalcemia-related complications and an elevated risk of parathyroid carcinoma. For this reason, early identification of the disease is important. We present the case of a 23-year-old woman who was found to have jaw tumours and was later diagnosed with PHPT. Genetic analysis revealed a novel mutation in exon 1 of CDC73. This report contributes to the understanding of the genetics of this rare syndrome. It also highlights the fact that HPT-JT should be considered and CDC73 mutation analysis should be performed in cases of early-onset PHPT associated with ossifying fibromas of the jaw.

  8. Brown tumor of the jaw after pregnancy and lactation in a MEN1 patient.

    PubMed

    Casteràs, Anna; Darder, Lídia; Zafon, Carles; Hueto, Juan Antonio; Alberola, Margarita; Caubet, Enric; Mesa, Jordi

    2016-01-01

    Skeletal manifestations of primary hyperparathyroidism (pHPT) include brown tumors (BT), which are osteoclastic focal lesions often localized in the jaws. Brown tumors are a rare manifestation of pHTP in Europe and USA; however, they are frequent in developing countries, probably related to vitamin D deficiency and longer duration and severity of disease. In the majority of cases, the removal of the parathyroid adenoma is enough for the bone to remineralize, but other cases require surgery. Hyperparathyroidism in MEN1 develops early, and is multiglandular and the timing of surgery remains questionable. To our knowledge, there are no reports of BT in MEN 1 patients. We present a 29-year-old woman with MEN 1 who developed a brown tumor of the jaw 24 months after getting pregnant, while breastfeeding. Serum corrected calcium remained under 2.7 during gestation, and at that point reached a maximum of 2.82 mmol/L. Concomitant PTH was 196 pg/mL, vitamin D 13.7 ng/mL and alkaline phosphatase 150 IU/L. Bone mineral density showed osteopenia on spine and femoral neck (both T-scores = -1.6). Total parathyroidectomy was performed within two weeks, with a failed glandular graft autotransplantation, leading to permanent hypoparathyroidism. Two months after removal of parathyroid glands, the jaw tumor did not shrink; thus, finally it was successfully excised. We hypothesize that higher vitamin D and mineral requirements during maternity may have triggered an accelerated bone resorption followed by appearance of the jaw BT. We suggest to treat pHPT before planning a pregnancy in MEN1 women or otherwise supplement with vitamin D, although this approach may precipitate severe hypercalcemia.

  9. Prototyping artificial jaws for the robotic dental testing simulator.

    PubMed

    Alemzadeh, K; Raabe, D

    2008-11-01

    This paper presents a robot periphery prototyped for the six-degrees-of-freedom robotic dental testing simulator, simulating the wear of materials on dental components, such as individual teeth, crowns, bridges, or a full set of teeth. The robot periphery consists of the artificial jaws and compliance module. The jaws have been reverse engineered and represent a human-like mandible and maxilla with artificial teeth. Each clinically fabricated tooth consists of a crown and glass ceramic roots which are connected using resin cement. Normal clinical occlusion of the artificial jaws assembly was emulated by a dental articulator based on 'Andrew's six keys to occlusion'. The radii of the von Spee curve, the Monson curve, and the Wilson curve were also measured as important jaw characteristic indicators to aid normal occlusion. A compliance module had to be built between the lower jaw and the robot platform to sustain the fluctuating forces that occur during normal chewing in the occlusal contact areas, where these high bite forces are major causes of dental component failure. A strain gauge force transducer has been integrated into the machined lower jaw, underneath the second molars, to measure axial biting forces applied to the posterior teeth. The experiments conducted have shown that the sensor is able to sense small changes in the compression force satisfactorily, when applied perpendicular to the occlusal surfaces of the teeth.

  10. Jaw movement during the speech in children with allergic rhinitis.

    PubMed

    Lima, Sandro Júnior Henrique; Pernambuco, Leandro de Araújo; Lins, Aline de Lima; Albuquerque, Lucas Carvalho Aragão; Silva, Hilton Justino da

    2015-01-01

    Allergic rhinitis can cause changes in stomatognathic functions, which may alter the mandibular dynamics. Electrognathography is used in the recording of jaw movements, making it valid for analysis of movements in speech. To characterize the amplitude and velocity of jaw movements during speech in children with and without allergic rhinitis. The sample consisted of 32 children aged 7-12 years, treated at a university hospital, divided into two groups: one with rhinitis and the other without rhinitis. To capture the jaw movements during speech, we used an electrognathography with the aid of a list of phonetically balanced figures. For the analysis of data, we used, in addition to descriptive statistics, nonparametric tests, Spearman correlation coefficient and the Mann-Whitney test, with a significant value of p=0.05. No significant difference was observed in jaw movements between groups, with values of p equals to 0.175, 0.650, and 0.462 for amplitude and jaw opening and closing velocity, respectively. However, a strong correlation was observed between the variables velocity and amplitude of mouth opening, being slightly higher in the group of children with allergic rhinitis. The amplitude and velocity of jaw movements are found to be similar in children with and without allergic rhinitis, and a correlation exits between these variables. In addition, they were more heterogeneous in the group without allergic rhinitis.

  11. Specification of jaw identity by the Hand2 transcription factor

    PubMed Central

    Funato, Noriko; Kokubo, Hiroki; Nakamura, Masataka; Yanagisawa, Hiromi; Saga, Yumiko

    2016-01-01

    Acquisition of the lower jaw (mandible) was evolutionarily important for jawed vertebrates. In humans, syndromic craniofacial malformations often accompany jaw anomalies. The basic helix-loop-helix transcription factor Hand2, which is conserved among jawed vertebrates, is expressed in the neural crest in the mandibular process but not in the maxillary process of the first branchial arch. Here, we provide evidence that Hand2 is sufficient for upper jaw (maxilla)-to-mandible transformation by regulating the expression of homeobox transcription factors in mice. Altered Hand2 expression in the neural crest transformed the maxillae into mandibles with duplicated Meckel’s cartilage, which resulted in an absence of the secondary palate. In Hand2-overexpressing mutants, non-Hox homeobox transcription factors were dysregulated. These results suggest that Hand2 regulates mandibular development through downstream genes of Hand2 and is therefore a major determinant of jaw identity. Hand2 may have influenced the evolutionary acquisition of the mandible and secondary palate. PMID:27329940

  12. Dental extraction following zoledronate, induces osteonecrosis in rat's jaw.

    PubMed

    Vidal-Gutiérrez, X; Gómez-Clavel, J-F; Gaitán-Cepeda, L-A

    2017-03-01

    Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) is clinically characterized by the presence of exposed bone in the oral cavity that persists for more than eight weeks. Previous attempts to establish an animal model have not sufficiently considered disease features. Our aim was to establish an inexpensive and replicable animal model that develops BRONJ in a short time. Thirty-two male Wistar rats were randomly divided into two groups: control and experimental. In the experimental group, we administered 0.06mg/kg intraperitoneal dose of zoledronic acid (ZA) 7 and 14 days prior to maxillary second molar extraction. At two, four and six weeks after tooth extraction, the animals were euthanized, and we dissected the maxilla following histological procedures. We stained serial slides with hematoxylin and eosin and Masson's trichrome. The samples were harvested for macroscopic, radiologic and histological evaluation of bone changes. At two weeks postextraction, we observed exposed necrotic bone in dental socket areas in experimental groups. Radiological analysis revealed osteolytic lesions accompanied by extensive destruction and sequestrum formation in the same group. Histological examination confirmed the absence of necrotic bone in control groups in contrast with the experimental groups. The percentage of empty lacunae and the number of osteoclasts and the necrotic bone area were significantly increased (p<0.05) in the experimental groups. The animal model using ZA administration to prior dental extraction successfully mimicked human BRONJ lesions. Also, the model was easily replicated, inexpensive and showed different features than other previous BRONJ models.

  13. Flexible piezoelectric energy harvesting from jaw movements

    NASA Astrophysics Data System (ADS)

    Delnavaz, Aidin; Voix, Jérémie

    2014-10-01

    Piezoelectric fiber composites (PFC) represent an interesting subset of smart materials that can function as sensor, actuator and energy converter. Despite their excellent potential for energy harvesting, very few PFC mechanisms have been developed to capture the human body power and convert it into an electric current to power wearable electronic devices. This paper provides a proof of concept for a head-mounted device with a PFC chin strap capable of harvesting energy from jaw movements. An electromechanical model based on the bond graph method is developed to predict the power output of the energy harvesting system. The optimum resistance value of the load and the best stretch ratio in the strap are also determined. A prototype was developed and tested and its performances were compared to the analytical model predictions. The proposed piezoelectric strap mechanism can be added to all types of head-mounted devices to power small-scale electronic devices such as hearing aids, electronic hearing protectors and communication earpieces.

  14. Jaw muscles of Old World squirrels.

    PubMed

    Thorington, R W; Darrow, K

    1996-11-01

    The jaw, suprahyoid, and extrinsic tongue muscles were studied in 11 genera, belonging to five tribes, of Old World squirrels. Significant variation in most of the adductor muscles is evident. The most primitive state of sciuromorphy is seen in the African tree squirrels Paraxerus and Funisciurus, especially as reflected in the anterior deep masseter. A derived state of sciuromorphy is found in five genera of Old World squirrels and perhaps evolved independently in each. Reduction of the temporalis muscle was observed in three genera, distantly related to one another. A unique arrangement of the superficial masseter is reported in the Asian giant tree squirrels, Ratufa. The arrangement of the masseter in the African pygmy squirrel, Myosciurus, is very similar to that of the South American pygmy squirrel, Sciurillus. We present hypotheses about the functional significance of these differences. In the derived state of sciuromorphy, which is found in three cases in squirrels that feed extensively on hard fruits, the anterior deep masseter is well positioned to increase the strength of the power stroke of the incisor bite. Among the pygmy squirrels, the position of the anterior deep masseter suggests that it plays a more significant role in molar chewing.

  15. [Bisphosphonates and osteonecrosis of the jaws].

    PubMed

    Urade, Masahiro

    2007-02-01

    The osteonecrosis of the jaws (ONJ) has been reported occasionally in cancer patients treated with radiotherapy and chemotherapy. However, bisphosphonate (BP)-associated ONJ in patients with cancer such as multiple myeloma, breast cancer and prostate cancer mainly administered with intravenous BPs has been first reported in 2003. Since then, many cases over 2,500 are accumulating worldwide. Since BPs are often used for osteoporosis, cancer-associated hypercalcemia and osteolytic bone metastasis, it is speculated that ONJ cases will increase in Japan where a small number of them were reported until now. Most of ONJ in cancer patients receiving BP administration occur after dental treatments such as tooth extraction, periodontal surgery and dental implants, and do not respond to conventional treatment modalities such as debridement, antibiotic therapy and hyperbaric oxygen therapy. No effective therapy for ONJ is established yet and empirical conservative therapy is recommended in the guidelines for prevention, diagnosis, and treatment of ONJ. Therefore, dentists and oral and maxillofacial surgeons need to recognize ONJ as a serious side effect of BPs and to make informed consent to the patients and a close consultation with medical oncologists for administration of BPs.

  16. Phosphorus Necrosis of the Jaw: A Present-day Study

    PubMed Central

    Hughes, J. P. W.; Baron, R.; Buckland, D. H.; Cooke, M. A.; Craig, J. D.; Duffield, D. P.; Grosart, A. W.; Parkes, P. W. J.; Porter, A.

    1962-01-01

    A historical note on the aetiology of phossy jaw shows that present-day knowledge is little greater than it was a century ago. The varied clinical course of the disease is described together with a report of 10 classical cases not previously reported. Six cases, not amounting to true necrosis but in which healing after dental extraction was delayed, and described, and mention is made of the noticeable differences in the oral state and appearances of tartar of healthy workmen exposed to phosphorus compared with healthy workmen not exposed. But no systematic differences of any kind were found in the incidence of general infections, fractures of bones, haematological findings, and biochemical studies of blood and urine in two groups of healthy men most exposed and least exposed to phosphorous in the same factory. An intensive study in hospital of a case of classical necrosis showed no departure from normal, except delayed healing following bone biopsy from the iliac crest, and a reversed polymorphonuclear/lymphocyte ratio. In the discussion the time of onset of necrosis after first exposure to phosphorus, clinical and radiological diagnosis, the organisms present, personal susceptibility, the appearance of the sequestra, and regeneration of bone are considered. An up-to-date note on prevention of the disease is given, although this has met with only partial success. Some persons are highly susceptible and, whilst complete protection is impossible in the light of our present knowledge, early diagnosis and modern treatment have robbed the disease of its terrible manifestations of Victorian times and turned it into a minor, although often uncomfortable complaint, with little or no resulting disability. Images PMID:14449812

  17. Lack of association between oral bisphosphonates and osteonecrosis using jaw surgery as a surrogate marker.

    PubMed

    Pazianas, M; Blumentals, W A; Miller, P D

    2008-06-01

    Using jaw surgery as a surrogate marker for osteonecrosis of the jaw, this exploratory study did not find that the risk of jaw surgery was significantly increased with the use of oral bisphosphonates in postmenopausal women. The objective of this analysis was to explore the potential association between jaw surgery (as a surrogate marker for osteonecrosis of the jaw) and the use of oral bisphosphonates in postmenopausal women. A claims database was used to identify female patients > or = 45 years of age with jaw surgery claims from January 1, 2002 to December 31, 2005. Four controls (patients with no claims for jaw surgery) were matched to each jaw surgery case. Additional patient data collected included oral bisphosphonate prescriptions (including alendronate, risedronate, or ibandronate) and comorbid conditions. A total of 697 jaw surgery cases and 2,808 controls were identified. Of those jaw surgery cases, 96 (13.8%) received at least one prescription for an oral bisphosphonate. After adjustment for confounding variables, receiving at least one oral bisphosphonate prescription was not shown to significantly increase the risk of jaw surgery (odds ratio(adjusted) = 0.91; 95% confidence interval = 0.70-1.19). When bisphosphonate use was stratified by duration on therapy, no significant increases in the risk of jaw surgery were observed in any group. This exploratory analysis did not find a significant association between oral bisphosphonate use and increased risk of jaw surgery, a surrogate marker for osteonecrosis of the jaw.

  18. Antiresorptive agent-related osteonecrosis of the jaw: Position Paper 2017 of the Japanese Allied Committee on Osteonecrosis of the Jaw.

    PubMed

    Yoneda, Toshiyuki; Hagino, Hiroshi; Sugimoto, Toshitsugu; Ohta, Hiroaki; Takahashi, Shunji; Soen, Satoshi; Taguchi, Akira; Nagata, Toshihiko; Urade, Masahiro; Shibahara, Takahiko; Toyosawa, Satoru

    2017-01-01

    Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is an intractable, though rare, complication in cancer patients with bone metastases and patients with osteoporosis who are treated with antiresorptive agents, including bisphosphonates and denosumab. Despite the more than 10 years that have passed since the first cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) were reported, our understanding of the epidemiology and pathophysiology of ARONJ remains limited, and data supported by evidence-based medicine are still sparse. However, the diagnosis and staging of ARONJ, identification of risk factors, and development of preventive and therapeutic approaches have advanced significantly over the past decade. The Position Paper 2017 is an updated version of the Position Paper 2010 of the Japanese Allied Committee on Osteonecrosis of the Jaw, which now comprises six Japanese academic societies. The Position Paper 2017 describes a new diagnostic definition for ARONJ, as proposed by the American Association of Oral and Maxillofacial Surgeons (AAOMS), summarizes our current understanding of the pathophysiology of ARONJ based on a literature search, and suggests methods for physicians and dentists/oral surgeons to manage the disease. In addition, the appropriateness of discontinuing antiresorptive medications (drug holiday) before, during, and after invasive dental treatments is discussed extensively. More importantly, the manuscript also proposes, for the first time, the importance of interactive communication and cooperation between physicians and dentists/oral surgeons for the successful treatment of ARONJ. The Position Paper 2017 is intended to serve as a guide for improving the management of ARONJ patients in Japan.

  19. Efficacy of laser therapy in the management of bisphosphonate-related osteonecrosis of the jaw (BRONJ): a systematic review.

    PubMed

    Weber, João Batista Blessmann; Camilotti, Renata Stifelman; Ponte, Monique Estér

    2016-08-01

    Bisphosphonate-related osteonecrosis of the jaw is a well-known potential side effect of long-term bisphosphonate therapy; the primary objective of the treatment should be to improve patient quality of life through pain and infection management, to prevent the development of new lesions, and to slow disease progression. In recent years, the use of laser for bisphosphonate-related osteonecrosis of the jaw has become more widespread, due to its use of administration and widely reported beneficial effects on tissue healing. The present systematic review of the literature sought to elucidate whether low-level laser therapy has positive effects on the treatment of bisphosphonate-related osteonecrosis of the jaw. We conducted a systematic search of the PubMed, EMBASE, and Cochrane Library electronic databases, with no restrictions on language or year of publication. Search strategies were formulated using keywords and Boolean operators. The electronic search strategy retrieved 55 records. From 55 articles, 16 were selected for full-text review, and of these, 10 were ultimately included for data analysis in this review. Our findings show that treatment modalities including laser were associated with superior outcomes in terms of cure or improvement of bisphosphonate-related osteonecrosis of the jaw lesions as compared with conventional surgical and/or conservative drug therapy. It can be concluded that combined treatment with antibiotics, minimally invasive surgery (including Er:YAG laser surgery), and low-level laser therapy in the early stages of the disease should be the gold standard for bisphosphonate-related osteonecrosis of the jaw management.

  20. Root canal therapy for the prevention of osteonecrosis of the jaws: an evidence-based clinical update.

    PubMed

    Kyrgidis, Athanassios; Arora, Amit; Lyroudia, Kleoniki; Antoniades, Konstantinos

    2010-12-01

    Osteonecrosis of the jaws is an adverse effect of bone preservation treatment. There is a sufficient body of evidence to associate osteonecrosis of the jaws development with dental extractions and trauma caused from ill-fitting dentures. In this review, we critically appraise available evidence about the clinical efficacy of root canal therapy in patients receiving bisphosphonates.We review a series of theories to explain why endodontic treatment is a safe clinical intervention to prevent osteonecrosis of the jaws in patients receiving bisphosphonates. Root canal therapy could postpone or even eradicate the need for dental extractions of carious teeth in patients on bisphosphonates who may develop osteonecrosis of the jaws. Patients receiving bisphosphonates should be offered the full range of preventive care to reduce their risk to both dental caries and periodontal disease, so that the need for both endodontic therapy and dental extractions will be reduced. Implementing such a strategy would require both practitioner and patient education through the combined efforts of medical and dental societies. Such an approach is justified, as the risk of compromising the oral health of patients on bisphosphonates undertaking endodontic treatment is negligible compared with the benefit from avoiding dental extractions.

  1. Risk Factors for Osteonecrosis of the Jaws

    PubMed Central

    Barasch, A.; Cunha-Cruz, J.; Curro, F.A.; Hujoel, P.; Sung, A.H.; Vena, D.; Voinea-Griffin, A.E.; Beadnell, Steven; Craig, Ronald G.; DeRouen, Timothy; Desaranayake, Ananda; Gilbert, Ann; Gilbert, Gregg H.; Goldberg, Ken; Hauley, Richard; Hashimoto, Mariko; Holmes, Jon; Latzke, Brooke; Leroux, Brian; Lindblad, Anne; Richman, Joshua; Safford, Monika; Ship [deceased], Jonathan; Thompson, Van P.; Williams, O. Dale; Yin, Wanrong

    2011-01-01

    Case reports and cohort studies have linked bisphosphonate therapy and osteonecrosis of the jaws (ONJ), but neither causality nor specific risks for lesion development have been clearly established. We conducted a 1:3 case-control study with three dental Practice-based Research Networks, using dentist questionnaires and patient interviews for collection of data on bisphosphonate therapy, demographics, co-morbidities, and dental and medical treatments. Multivariable logistic regression analyses tested associations between bisphosphonate use and other risk factors with ONJ. We enrolled 191 ONJ cases and 573 controls in 119 dental practices. Bisphosphonate use was strongly associated with ONJ (odds ratios [OR] 299.5 {95%CI 70.0-1282.7} for intravenous [IV] use and OR = 12.2 {4.3-35.0} for oral use). Risk markers included local suppuration (OR = 7.8 {1.8-34.1}), dental extraction (OR = 7.6 {2.4-24.7}), and radiation therapy (OR = 24.1 {4.9-118.4}). When cancer patients (n = 143) were excluded, bisphosphonate use (OR = 7.2 {2.1-24.7}), suppuration (OR = 11.9 {2.0-69.5}), and extractions (OR = 6.6 {1.6-26.6}) remained associated with ONJ. Higher risk of ONJ began within 2 years of bisphosphonate initiation and increased four-fold after 2 years. Both IV and oral bisphosphonate use were strongly associated with ONJ. Duration of treatment > 2 years; suppuration and dental extractions were independent risk factors for ONJ. PMID:21317246

  2. Brown tumor of the jaw after pregnancy and lactation in a MEN1 patient

    PubMed Central

    Darder, Lídia; Zafon, Carles; Hueto, Juan Antonio; Alberola, Margarita; Caubet, Enric; Mesa, Jordi

    2016-01-01

    Summary Skeletal manifestations of primary hyperparathyroidism (pHPT) include brown tumors (BT), which are osteoclastic focal lesions often localized in the jaws. Brown tumors are a rare manifestation of pHTP in Europe and USA; however, they are frequent in developing countries, probably related to vitamin D deficiency and longer duration and severity of disease. In the majority of cases, the removal of the parathyroid adenoma is enough for the bone to remineralize, but other cases require surgery. Hyperparathyroidism in MEN1 develops early, and is multiglandular and the timing of surgery remains questionable. To our knowledge, there are no reports of BT in MEN 1 patients. We present a 29-year-old woman with MEN 1 who developed a brown tumor of the jaw 24 months after getting pregnant, while breastfeeding. Serum corrected calcium remained under 2.7 during gestation, and at that point reached a maximum of 2.82 mmol/L. Concomitant PTH was 196 pg/mL, vitamin D 13.7 ng/mL and alkaline phosphatase 150 IU/L. Bone mineral density showed osteopenia on spine and femoral neck (both T-scores = −1.6). Total parathyroidectomy was performed within two weeks, with a failed glandular graft autotransplantation, leading to permanent hypoparathyroidism. Two months after removal of parathyroid glands, the jaw tumor did not shrink; thus, finally it was successfully excised. We hypothesize that higher vitamin D and mineral requirements during maternity may have triggered an accelerated bone resorption followed by appearance of the jaw BT. We suggest to treat pHPT before planning a pregnancy in MEN1 women or otherwise supplement with vitamin D, although this approach may precipitate severe hypercalcemia. Learning points: Brown tumors of the jaw can develop in MEN 1 patients with primary hyperparathyroidism at a young age (less than 30 years). Pregnancy and lactation might trigger brown tumors by increasing mineral and vitamin D requirements. Early parathyroidectomy is

  3. Neural crest cell-derived VEGF promotes embryonic jaw extension

    PubMed Central

    Wiszniak, Sophie; Mackenzie, Francesca E.; Anderson, Peter; Kabbara, Samuela; Ruhrberg, Christiana; Schwarz, Quenten

    2015-01-01

    Jaw morphogenesis depends on the growth of Meckel’s cartilage during embryogenesis. However, the cell types and signals that promote chondrocyte proliferation for Meckel’s cartilage growth are poorly defined. Here we show that neural crest cells (NCCs) and their derivatives provide an essential source of the vascular endothelial growth factor (VEGF) to enhance jaw vascularization and stabilize the major mandibular artery. We further show in two independent mouse models that blood vessels promote Meckel’s cartilage extension. Coculture experiments of arterial tissue with NCCs or chondrocytes demonstrated that NCC-derived VEGF promotes blood vessel growth and that blood vessels secrete factors to instruct chondrocyte proliferation. Computed tomography and X-ray scans of patients with hemifacial microsomia also showed that jaw hypoplasia correlates with mandibular artery dysgenesis. We conclude that cranial NCCs and their derivatives provide an essential source of VEGF to support blood vessel growth in the developing jaw, which in turn is essential for normal chondrocyte proliferation, and therefore jaw extension. PMID:25922531

  4. The evolutionary origin of jaw yaw in mammals

    PubMed Central

    Grossnickle, David M.

    2017-01-01

    Theria comprises all but three living mammalian genera and is one of the most ecologically pervasive clades on Earth. Yet, the origin and early history of therians and their close relatives (i.e., cladotherians) remains surprisingly enigmatic. A critical biological function that can be compared among early mammal groups is mastication. Morphometrics and modeling analyses of the jaws of Mesozoic mammals indicate that cladotherians evolved musculoskeletal anatomies that increase mechanical advantage during jaw rotation around a dorsoventrally-oriented axis (i.e., yaw) while decreasing the mechanical advantage of jaw rotation around a mediolaterally-oriented axis (i.e., pitch). These changes parallel molar transformations in early cladotherians that indicate their chewing cycles included significant transverse movement, likely produced via yaw rotation. Thus, I hypothesize that cladotherian molar morphologies and musculoskeletal jaw anatomies evolved concurrently with increased yaw rotation of the jaw during chewing cycles. The increased transverse movement resulting from yaw rotation may have been a crucial evolutionary prerequisite for the functionally versatile tribosphenic molar morphology, which underlies the molars of all therians and is retained by many extant clades. PMID:28322334

  5. Fossil jawless fish from China foreshadows early jawed vertebrate anatomy.

    PubMed

    Gai, Zhikun; Donoghue, Philip C J; Zhu, Min; Janvier, Philippe; Stampanoni, Marco

    2011-08-17

    Most living vertebrates are jawed vertebrates (gnathostomes), and the living jawless vertebrates (cyclostomes), hagfishes and lampreys, provide scarce information about the profound reorganization of the vertebrate skull during the evolutionary origin of jaws. The extinct bony jawless vertebrates, or 'ostracoderms', are regarded as precursors of jawed vertebrates and provide insight into this formative episode in vertebrate evolution. Here, using synchrotron radiation X-ray tomography, we describe the cranial anatomy of galeaspids, a 435-370-million-year-old 'ostracoderm' group from China and Vietnam. The paired nasal sacs of galeaspids are located anterolaterally in the braincase, and the hypophyseal duct opens anteriorly towards the oral cavity. These three structures (the paired nasal sacs and the hypophyseal duct) were thus already independent of each other, like in gnathostomes and unlike in cyclostomes and osteostracans (another 'ostracoderm' group), and therefore have the condition that current developmental models regard as prerequisites for the development of jaws. This indicates that the reorganization of vertebrate cranial anatomy was not driven deterministically by the evolutionary origin of jaws but occurred stepwise, ultimately allowing the rostral growth of ectomesenchyme that now characterizes gnathostome head development.

  6. The evolutionary origin of jaw yaw in mammals.

    PubMed

    Grossnickle, David M

    2017-03-21

    Theria comprises all but three living mammalian genera and is one of the most ecologically pervasive clades on Earth. Yet, the origin and early history of therians and their close relatives (i.e., cladotherians) remains surprisingly enigmatic. A critical biological function that can be compared among early mammal groups is mastication. Morphometrics and modeling analyses of the jaws of Mesozoic mammals indicate that cladotherians evolved musculoskeletal anatomies that increase mechanical advantage during jaw rotation around a dorsoventrally-oriented axis (i.e., yaw) while decreasing the mechanical advantage of jaw rotation around a mediolaterally-oriented axis (i.e., pitch). These changes parallel molar transformations in early cladotherians that indicate their chewing cycles included significant transverse movement, likely produced via yaw rotation. Thus, I hypothesize that cladotherian molar morphologies and musculoskeletal jaw anatomies evolved concurrently with increased yaw rotation of the jaw during chewing cycles. The increased transverse movement resulting from yaw rotation may have been a crucial evolutionary prerequisite for the functionally versatile tribosphenic molar morphology, which underlies the molars of all therians and is retained by many extant clades.

  7. Jaw muscle afferent firing during an isotonic jaw-positioning task in the monkey.

    PubMed

    Larson, C R; Finocchio, D V; Smith, A; Luschei, E S

    1983-07-01

    The activity of jaw muscle receptors was studied by recording neurons in the mesencephalic nucleus of the trigeminal nerve in monkeys trained to control the position and movement of their mandible. Jaw position was measured by a weighted lever resting on the mandibular incisors. The force required to maintain the position of the lever was varied; in most cases it was either 25 or 360 g. Firing rates of neurons were related to stationary mandibular positions and to the velocity of movements during intervals when the movement velocity was constant. Of 49 neurons studied in detail, 21 fired at rates that were consistently and linearly related to static incisal openings. This static position sensitivity was typically about 5 spikes/mm of incisal opening. Most position-sensitive neurons fired at higher rates during opening movements and at lower rates during closing movements than would be accounted for by their position sensitivity. This sensitivity to the velocity of movement was not linear, however; slow closing movements sometimes did not produce a decrease in firing rate, and an actual increase during muscle shortening was seen in a few instances. The position sensitivity of eight neurons was evaluated during different loading conditions; in no case did it change substantially. Of the remaining 28 neurons, 26 fired at high rates during all opening movements and either stopped firing or fired at low, sporadic rates during closing movements. The static position sensitivity of these neurons was weak and variable both within and between neurons. The velocity sensitivity of these stretch-sensitive neurons was very nonlinear. Except for a range of slow movements (+/- 5 mm/s), the firing rate was maximal (200 spikes/s or higher) for most opening movements and zero for most closing movements. Maximal firing rates were higher when the loads being moved were increased from 25 to 360 g. The majority of position-sensitive neurons exhibited a large interspike

  8. A monolateral TMJ replacement under intraoral endoscopic assistance for jaw osteomielitis: a modified approach.

    PubMed

    Belli, E; Mici, E; Mazzone, N; Catalfamo, L; Fini, G; Liberatore, G M

    2015-01-01

    Alloplastic replacement has become a valid treatment for TMJ endstage disease. The Alkayat and Bramley pre-auricular approach combined with the submandibular incision are the current surgical approaches for TMJ surgery. The present study shows a modified approach using intraoral endoscopic assistance. A female patient affected by jaw osteomielitis with condylar detachment was treated with total left TMJ alloplastic replacement combined with a right TMJ arthroplasty. No subamandibular incision was performed and, subsequently, the risks for permanent or temporary damage to the marginalis mandibulae nerve and surgical submandibular scar were avoided. Postoperative CT-Scan evidenced a good prosthesis position. No complications occurred after two years of follow-up.

  9. Important aspects regarding the role of microorganisms in bisphosphonate-related osteonecrosis of the jaws.

    PubMed

    Boff, Renata Chiapinotto; Salum, Fernanda Gonçalves; Figueiredo, Maria Antonia; Cherubini, Karen

    2014-08-01

    Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is an important side effect of bisphosphonates, whose etiopathogenesis has not been completely elucidated. Theories pointing to bone turnover and angiogenesis inhibition, as well as effects on epithelial cells of oral mucosa and the role of microorganisms have been reported. Nevertheless, the true contribution of each one of these factors to BRONJ is unknown. We present here a literature review focusing on important aspects regarding the role of microorganisms in BRONJ development. Knowledge about specific microbiota and its role in the etiopathogenesis of this disease can help the optimisation of preventive and therapeutic interventions in patients with or at-risk for BRONJ.

  10. Medication-Related Osteonecrosis of the Jaw: Basic and Translational Science Updates.

    PubMed

    Allen, Matthew R

    2015-11-01

    In the late 1990s and the early 2000s, bisphosphonates had become the clinical pillar of excellence for treating metabolic bone disease, and thus their connection with osteonecrosis of the jaw (ONJ) caused significant concern. Over the past decade, progress has been made in understanding what is now referred to as medication-related ONJ (MRONJ), because of its connections to agents other than bisphosphonates, although in many respects the progress has been slow. This review highlights the key basic science and translational (animal) studies in the area of MRONJ and suggests areas of focus as the field moves into the next decade. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Micro- and macroevolutionary decoupling of cichlid jaws: a test of Liem's key innovation hypothesis.

    PubMed

    Hulsey, C D; García de León, F J; Rodiles-Hernández, R

    2006-10-01

    The extent to which elements of functional systems can change independently (modularity) likely influences the diversification of lineages. Major innovations in organismal design, like the pharyngeal jaw in cichlid fishes, may be key to a group's success when they relax constraints on diversification by increasing phenotypic modularity. In cichlid fishes, pharyngeal jaw modifications that enhanced the ability to breakdown prey may have freed their oral jaws from serving their ancestral dual role as a site of both prey capture and prey processing. This functional decoupling that allowed the oral jaws to become devoted solely to prey capture has been hypothesized to have permitted the two sets of cichlid jaws to evolve independently. We tested the hypothesis that oral and pharyngeal jaw mechanics are evolutionarily decoupled both within and among Neotropical Heroine cichlids. In the trophically polymorphic species Herichthys minckleyi, molariforms that exhibit enlarged molarlike pharyngeal jaw teeth were found to have approximately 400% greater lower jaw mass compared to H. minckleyi with the alternative papilliform pharyngeal morphology. However, oral jaw gape, lower jaw velocity ratios, anterior jaw linkage mechanics, and jaw protrusion did not differ between the morphotypes. In 40 other Heroine species, there was a weak correlation between oral jaw mechanics and pharyngeal jaw mass when phylogenetic history was ignored. Yet, after expansion of the cytochrome b phylogeny for Heroines, change in oral jaw mechanics was found to be independent of evolutionary change in pharyngeal jaw mass based on independent contrasts. Evolutionary decoupling of oral and pharyngeal jaw mechanics has likely played a critical role in the unparalleled trophic diversification of cichlid fishes.

  12. Jaw-opening accuracy is not affected by masseter muscle vibration in healthy men.

    PubMed

    Wiesinger, B; Häggman-Henrikson, B; Wänman, A; Lindkvist, M; Hellström, F

    2014-11-01

    There is a functional integration between the jaw and neck regions with head extension-flexion movements during jaw-opening/closing tasks. We recently reported that trigeminal nociceptive input by injection of hypertonic saline into the masseter muscle altered this integrated jaw-neck function during jaw-opening/closing tasks. Thus, in jaw-opening to a predefined position, the head-neck component increased during pain. Previous studies have indicated that muscle spindle stimulation by vibration of the masseter muscle may influence jaw movement amplitudes, but the possible effect on the integrated jaw-neck function is unknown. The aim of this study was to investigate the effect of masseter muscle vibration on jaw-head movements during a continuous jaw-opening/closing task to a target position. Sixteen healthy men performed two trials without vibration (Control) and two trials with bilateral masseter muscle vibration (Vibration). Movements of the mandible and the head were registered with a wireless three-dimensional optoelectronic recording system. Differences in jaw-opening and head movement amplitudes between Control and Vibration, as well as achievement of the predefined jaw-opening target position, were analysed with Wilcoxon's matched pairs test. No significant group effects from vibration were found for jaw or head movement amplitudes, or in the achievement of the target jaw-opening position. A covariation between the jaw and head movement amplitudes was observed. The results imply a high stability for the jaw motor system in a target jaw-opening task and that this task was achieved with the head-neck and jaw working as an integrated system.

  13. Bioengineered Dental Tissues Grown in the Rat Jaw

    PubMed Central

    Duailibi, S.E.; Duailibi, M.T.; Zhang, W.; Asrican, R.; Vacanti, J.P.; Yelick, P.C.

    2009-01-01

    Our long-term objective is to develop methods to form, in the jaw, bioengineered replacement teeth that exhibit physical properties and functions similar to those of natural teeth. Our results show that cultured rat tooth bud cells, seeded onto biodegradable scaffolds, implanted into the jaws of adult rat hosts and grown for 12 weeks, formed small, organized, bioengineered tooth crowns, containing dentin, enamel, pulp, and periodontal ligament tissues, similar to identical cell-seeded scaffolds implanted and grown in the omentum. Radiographic, histological, and immunohistochemical analyses showed that bioengineered teeth consisted of organized dentin, enamel, and pulp tissues. This study advances practical applications for dental tissue engineering by demonstrating that bioengineered tooth tissues can be regenerated at the site of previously lost teeth, and supports the use of tissue engineering strategies in humans, to regenerate previously lost and/or missing teeth. The results presented in this report support the feasibility of bioengineered replacement tooth formation in the jaw. PMID:18650546

  14. Evaluation of an algorithm ascertaining cases of osteonecrosis of the jaw in the Swedish National Patient Register

    PubMed Central

    Bergdahl, Johan; Jarnbring, Fredrik; Ehrenstein, Vera; Gammelager, Henrik; Granath, Fredrik; Kieler, Helle; Svensson, Madeleine; Tell, Grethe S; Lagerros, Ylva Trolle

    2013-01-01

    Background Osteonecrosis of the jaw (ONJ) is a medical condition associated with antiresorptive drugs, among others, used to treat osteoporosis and bone metastasis. Currently, there is no consensus regarding the definition of ONJ, and no ONJ-specific International Classification of Diseases-10 code exists. Therefore, register-based studies of this condition may be troublesome. Purpose To evaluate an algorithm ascertaining ONJ cases in an attempt to facilitate future assessments of ONJ in clinical and epidemiological studies. Methods By means of the Patient Register and the Prescribed Drug Register, we identified all postmenopausal female residents in Sweden from 2005 through 2009. To identify potential cases of ONJ, we employed an algorithm including the following conditions: periapical abscess with sinus, inflammatory conditions of jaws, alveolitis of jaws, idiopathic aseptic necrosis of bone, osteonecrosis due to drugs, osteonecrosis due to previous trauma, other secondary osteonecrosis, other osteonecrosis, and unspecified osteonecrosis. Women seen at departments of oral and maxillofacial surgery, with at least one of the conditions, were classified as potential cases of ONJ. Conditions in anatomic sites other than the jaw were excluded. Validation was performed through medical record review. Case confirmation was based on the ONJ definition by the American Association of Oral and Maxillofacial Surgeons. The algorithm was evaluated by positive predictive values (PPVs) stratified by diagnosis. Results For the 87 potential cases identified through our algorithm, the medical records were obtained for 83. The overall PPV was 18% (95% confidence interval (CI) 10%–28%). The highest PPV was observed in osteonecrosis due to drugs (83%, 95% CI 36%–100%). Several diagnoses had a PPV of 0 or were not used at all (periapical abscess with sinus, alveolitis of jaws, idiopathic aseptic necrosis of bone, osteonecrosis due to previous trauma, other secondary osteonecrosis

  15. Reflex control of human jaw muscles.

    PubMed

    Türker, Kemal S

    2002-01-01

    The aim of this review is to discuss what is known about the reflex control of the human masticatory system and to propose a method for standardized investigation. Literature regarding the current knowledge of activation of jaw muscles, receptors involved in the feedback control, and reflex pathways is discussed. The reflexes are discussed under the headings of the stimulation conditions. This was deliberately done to remind the reader that under each stimulation condition, several receptor systems are activated, and that it is not yet possible to stimulate only one afferent system in isolation in human mastication experiments. To achieve a method for uniform investigation, we need to set a method for stimulation of the afferent pathway under study with minimal simultaneous activation of other receptor systems. This stimulation should also be done in an efficient and reproducible way. To substantiate our conviction to standardize the stimulus type and parameters, we discuss the advantages and disadvantages of mechanical and electrical stimuli. For mechanical stimulus to be delivered in a reproducible way, the following precautions are suggested: The stimulus delivery system (often a probe attached to a vibrator) should be brought into secure contact with the area of stimulation. To minimize the slack between the probe, the area to be stimulated should be taken up by the application of pre-load, and the delivered force should be recorded in series. Electrical stimulus has advantages in that it can be delivered in a reproducible way, though its physiological relevance can be questioned. It is also necessary to standardize the method for recording and analyzing the responses of the motoneurons to the stimulation. For that, a new technique is introduced, and its advantages over the currently used methods are discussed. The new method can illustrate the synaptic potential that is induced in the motoneurons without the errors that are unavoidable in the current

  16. Prevalence of bisphosphonate associated osteonecrosis of the jaw within the field of osteonecrosis.

    PubMed

    Walter, Christian; Grötz, Knut A; Kunkel, Martin; Al-Nawas, Bilal

    2007-02-01

    Prevalence of bisphosphonate-associated osteonecrosis of the jaws within the catchment area of a university hospital maxillofacial unit and to review the outcome of treatment. In a retrospective study, all patients with osteonecrosis, osteomyelitis and osteoradionecrosis treated in the period from January 2000 to March 2005 in the department for Maxillo Facial Surgery at the University of Mainz, Germany were analysed. Forty percent of the patients are grouped to odontogenic or surgically induced osteomyelitis. The second largest group (28%) were patients with osteoradionecrosis (ORN). Ten percent of all patients developed an osteonecrosis after treatment with bisphosphonates (BOJ). Eight percent showed osteomyelitis or sequester due to a trauma while 14% of all patients had osteomyelitis of unknown origin. All BOJ patients took bisphosphonates because of metastatic diseases of the bone (plasmocytoma, mamma carcinoma and prostate cancer) for up to 5 years. All had been administered a nitrogen-containing bisphosphonate (either pamidronat or zoledronat). Thirteen out of the 17 patients with BOJ and 14 of the 45 with ORN reported a possible trigger like previous tooth extraction, pressure denture sore or periodontal diseases. These findings support the association of bisphosphonate therapy and osteonecrosis of the jaw. The importance of this new disease is characterised by the growing number of patients. The role of dental trigger factors and the poor surgical outcome both seem to justify a prophylactic dental care concept in high-risk patients.

  17. Osteomalacia: The Missing Link in the Pathogenesis of Bisphosphonate-Related Osteonecrosis of the Jaws?

    PubMed Central

    Saia, Giorgia; Bettini, Giordana; Tronchet, Anita; Totola, Andrea; Bedogni, Giorgio; Tregnago, Paolo; Valenti, Maria Teresa; Bertoldo, Francesco; Ferronato, Giuseppe; Nocini, Pier Francesco; Blandamura, Stella; Dalle Carbonare, Luca

    2012-01-01

    Background. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a well-documented adverse event from treatment with nitrogen-containing bisphosphonates (NBPs). During a preliminary histomorphometric study aimed at assessing the rate of bone remodeling in the jaws of patients with surgically resected BRONJ, we found a defect of bone mineralization (unpublished data). We hypothesized that osteomalacia could be a risk factor for BRONJ in patients taking NBPs. Therefore, we looked for static and dynamic histomorphometric evidence of osteomalacia in biopsies from subjects with and without BRONJ. Methods. This case-control study used histomorphometric analysis of bone specimens of patients using NBPs (22 patients with BRONJ and 21 patients without BRONJ) who required oral surgical interventions for the treatment/prevention of osteonecrosis. Patients were given tetracycline hydrochloride according to a standardized protocol before taking bone biopsies from their jaws. Biopsies with evidence of osteomyelitis or necrosis at histology were excluded from the study. Osteomalacia was defined as a mineralization lag time >100 days, a corrected mean osteoid thickness >12.5 mm, and an osteoid volume >10%. Results. In all, 77% of patients with BRONJ were osteomalacic compared with 5% of patients without BRONJ, according to histomorphometry. Because osteomalacia was found almost exclusively in NBP users with BRONJ, this is likely to be a generalized process in which the use of NBPs further deteriorates mechanisms of bone repair. Conclusions. Osteomalacia represents a new and previously unreported risk factor for disease development. This finding may contribute to a better understanding of the pathogenesis of this disease and help with the development of strategies to increase the safety of NBP administration. PMID:22723507

  18. The origin and early phylogenetic history of jawed vertebrates.

    PubMed

    Brazeau, Martin D; Friedman, Matt

    2015-04-23

    Fossils of early gnathostomes (or jawed vertebrates) have been the focus of study for nearly two centuries. They yield key clues about the evolutionary assembly of the group's common body plan, as well the divergence of the two living gnathostome lineages: the cartilaginous and bony vertebrates. A series of remarkable new palaeontological discoveries, analytical advances and innovative reinterpretations of existing fossil archives have fundamentally altered a decades-old consensus on the relationships of extinct gnathostomes, delivering a new evolutionary framework for exploring major questions that remain unanswered, including the origin of jaws.

  19. A dynamic model of mouth closing movements in clariid catfishes: the role of enlarged jaw adductors.

    PubMed

    Van Wassenbergh, Sam; Aerts, Peter; Adriaens, Dominique; Herrel, Anthony

    2005-05-07

    Some species of Clariidae (air breathing catfishes) have extremely large (hypertrophied) jaw closure muscles. Besides producing higher bite forces, the enlarged muscles may also cause higher accelerations of the lower jaw during rapid mouth closure. Thus, jaw adductor hypertrophy could potentially also enable faster mouth closure. In this study, a forward dynamic model of jaw closing is developed to evaluate the importance of jaw adductor hypertrophy on the speed of mouth closure. The model includes inertia, pressure, tissue resistance and hydrodynamic drag forces on the lower jaw, which is modelled as a rotating half-ellipse. Simulations are run for four clariid species showing a gradual increase in jaw adductor hypertrophy (Clarias gariepinus, Clariallabes longicauda, Gymnallabes typus and Channallabes apus). The model was validated using data from high-speed videos of prey captures in these species. In general, the kinematic profiles of the fastest mouth closure from each species are reasonably well predicted by the model. The model was also used to compare the four species during standardized mouth closures (same initial gape angle, travel distance and cranial size). These simulations suggest that the species with enlarged jaw adductors have an increased speed of jaw closure (in comparison with the non-hypertrophied C. gariepinus) for short lower jaw rotations and when feeding at high gape angles. Consequently, the jaw system in these species seems well equipped to capture relatively large, evasive prey. For prey captures during which the lower jaw rotates freely over a larger distance before impacting the prey, the higher kinematic efficiency of the C. gariepinus jaw system results in the fastest jaw closures. In all cases, the model predicts that an increase in the physiological cross-sectional area of the jaw muscles does indeed contribute to the speed of jaw closure in clariid fish.

  20. The relationships among jaw-muscle fiber architecture, jaw morphology, and feeding behavior in extant apes and modern humans.

    PubMed

    Taylor, Andrea B; Vinyard, Christopher J

    2013-05-01

    The jaw-closing muscles are responsible for generating many of the forces and movements associated with feeding. Muscle physiologic cross-sectional area (PCSA) and fiber length are two architectural parameters that heavily influence muscle function. While there have been numerous comparative studies of hominoid and hominin craniodental and mandibular morphology, little is known about hominoid jaw-muscle fiber architecture. We present novel data on masseter and temporalis internal muscle architecture for small- and large-bodied hominoids. Hominoid scaling patterns are evaluated and compared with representative New- (Cebus) and Old-World (Macaca) monkeys. Variation in hominoid jaw-muscle fiber architecture is related to both absolute size and allometry. PCSAs scale close to isometry relative to jaw length in anthropoids, but likely with positive allometry in hominoids. Thus, large-bodied apes may be capable of generating both absolutely and relatively greater muscle forces compared with smaller-bodied apes and monkeys. Compared with extant apes, modern humans exhibit a reduction in masseter PCSA relative to condyle-M1 length but retain relatively long fibers, suggesting humans may have sacrificed relative masseter muscle force during chewing without appreciably altering muscle excursion/contraction velocity. Lastly, craniometric estimates of PCSAs underestimate hominoid masseter and temporalis PCSAs by more than 50% in gorillas, and overestimate masseter PCSA by as much as 30% in humans. These findings underscore the difficulty of accurately estimating jaw-muscle fiber architecture from craniometric measures and suggest models of fossil hominin and hominoid bite forces will be improved by incorporating architectural data in estimating jaw-muscle forces. Copyright © 2013 Wiley Periodicals, Inc.

  1. Role of FNAC in the diagnosis of intraosseous jaw lesions

    PubMed Central

    Goyal, Surbhi; Kotru, Mrinalini; Gupta, Neelima

    2015-01-01

    Background FNAC of intraosseous jaw lesions has not been widely utilized for diagnosis due to rarity and diversity of these lesions, limited experience and lack of well established cytological features. Aim of the study was to determine the role of FNAC in the diagnosis of intraosseous jaw swellings. Material and Methods 42 patients underwent FNAC over a period of 7 years (2007-2013), of which 37 (88.1%) aspirates were diagnostic. Histopathology correlation was available in 33 cases and diagnostic accuracy of FNAC was calculated. Results Lesions were categorized into inflammatory 3, cysts/hamartomas 15 and neoplasms 19. Mandibular and maxillary involvement was seen in 21 and 16 patients respectively. Of these, benign cysts and malignant lesions were commonest, accounting for 27% lesions (10 cases) each. One case of cystic ameloblastoma was misdiagnosed as odontogenic cyst on cytology. Overall, sensitivity and specificity of FNAC were 94.7% and 100% respectively with a diagnostic accuracy of 97.3%. Definitive categorization of giant cell lesions, fibro-osseous lesions, odontogenic tumors and cystic lesions was not feasible on FNAC. Conclusions FNAC is a simple, safe and minimally invasive first line investigation which can render an accurate preoperative diagnosis of intraosseous jaw lesions, especially the malignant ones in the light of clinic-radiological correlation. Key words: Jaw swellings, intraosseous, FNAC. PMID:25662547

  2. 21 CFR 872.2060 - Jaw tracking device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... powered device that measures and records anatomical distances and angles in three dimensional space, to..., while at rest and during jaw movement. (2) Classification. Class I (general controls). The device is... position of the mandible in three dimensional space, with respect to the location and position of the...

  3. Jaw-Phonatory Coordination in Chronic Developmental Stuttering

    ERIC Educational Resources Information Center

    Loucks, Torrey M. J.; De Nil, Luc F.; Sasisekaran, Jayanthi

    2007-01-01

    A deficiency in sensorimotor integration in a person who stutters may be a factor in the pathophysiology of developmental stuttering. To test oral sensorimotor function in adults who stutter, we used a task that requires the coordination of a jaw-opening movement with phonation onset. The task was adapted from previous limb coordination studies,…

  4. The Sequential Development of Jaw and Lip Control for Speech

    PubMed Central

    Green, Jordan R.; Moore, Christopher A.; Reilly, Kevin J.

    2010-01-01

    Vertical displacements of the upper lip, lower lip, and jaw during speech were recorded for groups of 1-, 2-, and 6-year-olds and adults to examine if control over these articulators develops sequentially. All movement traces were amplitude- and time-normalized. The developmental course of upper lip, lower lip, and jaw control was examined by quantifying age-related changes in the similarity of each articulator's movement patterns to those produced by adult subjects and by same-age peers. In addition, differences in token-to-token stability of articulatory movement were assessed among the different age groups. The experimental findings revealed that 1- and 2-year-old children's jaw movements were significantly more adult-like than their upper and lower lip movements, which were more variable. In contrast, upper and lower lip movement patterns became more adult-like with maturation. These findings suggest that the earliest stages of speech motor development are constrained by the nonuniform development of articulatory control, with the jaw preceding the lips. The observed developmental patterns suggest that the properties of the oral motor control system significantly influence the pattern of speech sound acquisition. PMID:14748639

  5. Tongue-jaw kinematic correlates of /s/ spectra

    NASA Astrophysics Data System (ADS)

    Dembowski, James S.; Crumb, Richard K.

    2004-05-01

    Frequencies of spectral peaks for fricatives are determined by the size of the resonating cavity anterior to the place of articulatory constriction in the upper vocal tract. For /s/, this cavity size may be altered through anterior-posterior (a-p) movements of the tongue blade forming the constriction, changes of jaw height, and degree of lip protrusion. With respect to intensity, modeling studies suggest that intensity of fricative spectral peaks may be related to degree of articulatory constriction. These spectral-kinematic relationships have been little studied in natural speech. This study used data from the University of Wisconsin X-Ray Microbeam Database to examine the relationship between spectral peaks and movements of the tongue and jaw in the /s/ productions of one normal speaker. Results showed no relationship between a-p tongue position and frequency of spectral peaks. However, a significant inverse correlation related peak between frequency and jaw opening. Thus, for this speaker jaw height appeared a more important determinant of spectral variability for /s/ than tongue position. Additional results showed a significant relationship between peak intensity and distance of the tongue blade from the palate. These natural speech data will be discussed with respect to models and theories of fricative production.

  6. Embryology and Anatomy of the Jaw and Dentition.

    PubMed

    Zohrabian, Vahe M; Poon, Colin S; Abrahams, James J

    2015-10-01

    Radiologists should possess working knowledge of the embryological development and anatomy of the jaw and dentition in order to aid in the diagnosis of both simple and complex disorders that affect them. Here, we review the elaborate process of odontogenesis, as well as describe in detail the anatomy of a tooth and its surrounding structures.

  7. DETAIL VIEW OF ORE BINS AND JAW CRUSHER, LOOKING NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF ORE BINS AND JAW CRUSHER, LOOKING NORTHWEST FROM NEARBY THE ENGINE. THE CONCRETE MACHINE PAD TO THE RIGHT OF THE CRUSHER PROBABLY HELD THE ENGINE THAT DROVE THE CRUSHER. - Gold Hill Mill, Warm Spring Canyon Road, Death Valley Junction, Inyo County, CA

  8. 12. CLOSEUP OF THE CURRENT TRASH RAKELIFTING MECHANISM (CALLED 'JAWS' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. CLOSE-UP OF THE CURRENT TRASH RAKE-LIFTING MECHANISM (CALLED 'JAWS' BY THE PRESENT OPERATORS), LOOKING WEST. THIS EQUIPMENT WAS REMOVED IN AUTUMN OF 1996. - Washington Water Power Company Post Falls Power Plant, Middle Channel Powerhouse & Dam, West of intersection of Spokane & Fourth Streets, Post Falls, Kootenai County, ID

  9. Jaw muscularization requires Dlx expression by cranial neural crest cells

    PubMed Central

    Heude, Églantine; Bouhali, Kamal; Kurihara, Yukiko; Kurihara, Hiroki; Couly, Gérard; Janvier, Philippe; Levi, Giovanni

    2010-01-01

    The origin of active predation in vertebrates is associated with the rise of three major, uniquely derived developmental characteristics of the head: (i) migratory cranial neural crest cells (CNCCs) giving rise to most skeletal skull elements; (ii) expression of Dlx genes by CNCCs in the Hox-free first pharyngeal arch (PA1); and (iii) muscularization of PA1 derivatives. Here we show that these three innovations are tightly linked. Expression of Dlx genes by CNCCs is not only necessary for head skeletogenesis, but also for the determination, differentiation, and patterning of cephalic myogenic mesoderm leading to masticatory muscle formation. In particular, inactivation of Dlx5 and Dlx6 in the mouse results in loss of jaw muscles. As Dlx5/6 are not expressed by the myogenic mesoderm, our findings imply an instructive role for Dlx5/6-positive CNCCs in muscle formation. The defect in muscularization does not result from the loss of mandibular identity observed in Dlx5/6−/− mice because masticatory muscles are still present in EdnRA−/− mutants, which display a similar jaw transformation. The genesis of jaws and their muscularization should therefore be seen as an integrated Dlx-dependent developmental process at the origin of the vertebrate head. The role of Dlx genes in defining gnathostome jaw identity could, therefore, be secondary to a more primitive function in the genesis of the oral skeletomuscular system. PMID:20534536

  10. Pediatric odontogenic tumor of the jaw - a case report.

    PubMed

    Muddana, Keerthi; Pasupula, Ajay Prakash; Dorankula, Shyam Prasad Reddy; Thokala, Madhusudan Rao; Muppallai, Jaya Nagendra Krishna

    2014-02-01

    Central jaw tumors (intra osseous) in children occur infrequently and few oral pathologists have had the opportunity or experience in diagnosing these lesions and predicting their biological behavior. Some children are not diagnosed correctly at the initial stages as having a neoplasm and are wrongly treated for infections by antibiotic administration. Subsequent to an unresponsive antibiotic therapy radiographs are taken to reveal a radiolucent or radio dense lesion in the jaws. Finally a tissue diagnosis becomes necessary in order to diagnose and initiate proper therapy. One among the central jaw tumors that occur infrequently in children is Ameloblastoma. It is often aggressive and destructive, with the capacity to attain great size, erode bone and invade adjacent structures. Ameloblastoma not only accounts for 1% of all tumors of maxilla and mandible but also 11% of all odontogenic tumors. It has a high percentage of local recurrence rate and possible malignant development when treated inadequately. Here we present a central jaw tumor in an 8-year-old child which was a case of unusually large plexiform ameloblastoma involving entire ramus up to the condyle, and part of body of the mandible.

  11. Osteonecrosis of the jaw associated with ziv-aflibercept

    PubMed Central

    Enzinger, Peter; McCleary, Nadine; Manon, Reshma; Villa, Alessandro; Treister, Nathaniel; Woo, Sook-Bin

    2016-01-01

    Medication-related osteonecrosis of the jaw (MRONJ) has been associated with medications that include bisphosphonates (BPs), denosumab, bevacizumab and sunitinib. Ziv-aflibercept is a recombinant human vascular endothelial growth factor (VEGF) receptor which has been used to treat patients with various advanced solid tumors. We report three patients without a history of the use of medications known to cause MRONJ presenting with jaw osteonecrosis typical for MRONJ following therapy with ziv-aflibercept. All patients had metastatic gastrointestinal cancer treated with ziv-aflibercept and were evaluated for MRONJ because of exposed bone in the oral cavity. None of the patients had received antiresorptive therapies or any other medication known to cause MRONJ, and none had received radiation therapy to the jaws. Patients were aged 43, 51, 63 and all were males. Patients received 7, 16 and 23 cycles of ziv-aflibercept treatment and developed necrotic bone. All three patients presented with mandibular involvement, with two reporting pain. Patients were managed with anti-microbial mouth rinse, antibiotics and non-surgical sequestrectomy and followed up for 1.5, 2, and 2 months; two patients became asymptomatic while one patient continued to have pain. These three reported patients with a history of ziv-aflibercept therapy and no reported use of other medications known to cause MRONJ developed exposed necrotic bone of the jaw. We believe that ziv-aflibercept is another medication that can potentially cause MRONJ probably through its anti-VEGF activity, similar to bevacizumab and sunitinib. PMID:28078129

  12. Spectral characteristics of speech with fixed jaw displacements

    NASA Astrophysics Data System (ADS)

    Solomon, Nancy P.; Makashay, Matthew J.; Munson, Benjamin

    2004-05-01

    During speech, movements of the mandible and the tongue are interdependent. For some research purposes, the mandible may be constrained to ensure independent tongue motion. To examine specific spectral characteristics of speech with different jaw positions, ten normal adults produced sentences with multiple instances of /t/, /s/, /squflg/, /i/, /ai/, and /squflgi/. Talkers produced stimuli with the jaw free to vary, and while gently biting on 2- and 5-mm bite blocks unilaterally. Spectral moments of /s/ and /squflg/ frication and /t/ bursts differed such that mean spectral energy decreased, and diffuseness and skewness increased with bite blocks. The specific size of the bite block had minimal effect on these results, which were most consistent for /s/. Formant analysis for the vocoids revealed lower F2 frequency in /i/ and at the end of the transition in /ai/ when bite blocks were used; F2 slope for diphthongs was not sensitive to differences in jaw position. Two potential explanations for these results involve the physical presence of the bite blocks in the lateral oral cavity, and the oromotor system's ability to compensate for fixed jaw displacements. [Work supported by NIDCD R03-DC06096.

  13. Jaw-Phonatory Coordination in Chronic Developmental Stuttering

    ERIC Educational Resources Information Center

    Loucks, Torrey M. J.; De Nil, Luc F.; Sasisekaran, Jayanthi

    2007-01-01

    A deficiency in sensorimotor integration in a person who stutters may be a factor in the pathophysiology of developmental stuttering. To test oral sensorimotor function in adults who stutter, we used a task that requires the coordination of a jaw-opening movement with phonation onset. The task was adapted from previous limb coordination studies,…

  14. Building Finite Element Models to Investigate Zebrafish Jaw Biomechanics

    PubMed Central

    Brunt, Lucy H.; Roddy, Karen A.; Rayfield, Emily J.; Hammond, Chrissy L.

    2016-01-01

    Skeletal morphogenesis occurs through tightly regulated cell behaviors during development; many cell types alter their behavior in response to mechanical strain. Skeletal joints are subjected to dynamic mechanical loading. Finite element analysis (FEA) is a computational method, frequently used in engineering that can predict how a material or structure will respond to mechanical input. By dividing a whole system (in this case the zebrafish jaw skeleton) into a mesh of smaller 'finite elements', FEA can be used to calculate the mechanical response of the structure to external loads. The results can be visualized in many ways including as a 'heat map' showing the position of maximum and minimum principal strains (a positive principal strain indicates tension while a negative indicates compression. The maximum and minimum refer the largest and smallest strain). These can be used to identify which regions of the jaw and therefore which cells are likely to be under particularly high tensional or compressional loads during jaw movement and can therefore be used to identify relationships between mechanical strain and cell behavior. This protocol describes the steps to generate Finite Element models from confocal image data on the musculoskeletal system, using the zebrafish lower jaw as a practical example. The protocol leads the reader through a series of steps: 1) staining of the musculoskeletal components, 2) imaging the musculoskeletal components, 3) building a 3 dimensional (3D) surface, 4) generating a mesh of Finite Elements, 5) solving the FEA and finally 6) validating the results by comparison to real displacements seen in movements of the fish jaw. PMID:28060270

  15. Dynamic Jaws and Dynamic Couch in Helical Tomotherapy

    SciTech Connect

    Sterzing, Florian; Uhl, Matthias; Hauswald, Henrik; Schubert, Kai; Sroka-Perez, Gabriele; Chen Yu; Lu Weiguo; Mackie, Rock; Debus, Juergen; Herfarth, Klaus; Oliveira, Gustavo

    2010-03-15

    Purpose: To investigate the next generation of helical tomotherapy delivery with dynamic jaw and dynamic couch movements. Methods and Materials: The new technique of dynamic jaw and dynamic couch movements is described, and a comparative planning study is performed. Ten nasopharyngeal cancer patients with skull base infiltration were chosen for this comparison of longitudinal dose profiles using regular tomotherapy delivery, running-start-stop treatment, and dynamic jaw and dynamic couch delivery. A multifocal simultaneous integrated boost concept was used (70.4Gy to the primary tumor and involved lymph nodes; 57.4Gy to the bilateral cervical lymphatic drainage pathways, 32 fractions). Target coverage, conformity, homogeneity, sparing of organs at risk, integral dose, and radiation delivery time were evaluated. Results: Mean parotid dose for all different deliveries was between 24.8 and 26.1Gy, without significant differences. The mean integral dose was lowered by 6.3% by using the dynamic technique, in comparison with a 2.5-cm-field width for regular delivery and 16.7% with 5-cm-field width for regular delivery. Dynamic jaw and couch movements reduced the calculated radiation time by 66% of the time required with regular 2.5-cm-field width delivery (199 sec vs. 595 sec, p < 0.001). Conclusions: The current delivery mode of helical tomotherapy produces dose distributions with conformal avoidance of parotid glands, brain stem, and spinal cord. The new technology with dynamic jaw and couch movements improves the plan quality by reducing the dose penumbra and thereby reducing the integral dose. In addition, radiation time is reduced by 66% of the regular delivery time.

  16. The adaptive response of jaw muscles to varying functional demands.

    PubMed

    Grünheid, Thorsten; Langenbach, Geerling E J; Korfage, Joannes A M; Zentner, Andrej; van Eijden, Theo M G J

    2009-12-01

    Jaw muscles are versatile entities that are able to adapt their anatomical characteristics, such as size, cross-sectional area, and fibre properties, to altered functional demands. The dynamic nature of muscle fibres allows them to change their phenotype to optimize the required contractile function while minimizing energy use. Changes in these anatomical parameters are associated with changes in neuromuscular activity as the pattern of muscle activation by the central nervous system plays an important role in the modulation of muscle properties. This review summarizes the adaptive response of jaw muscles to various stimuli or perturbations in the orofacial system and addresses general changes in muscles as they adapt, specific adaptive changes in jaw muscles under various physiologic and pathologic conditions, and their adaptive response to non-surgical and surgical therapeutic interventions. Although the jaw muscles are used concertedly in the masticatory system, their adaptive changes are not always uniform and vary with the nature, intensity, and duration of the stimulus. In general, stretch, increases neuromuscular activity, and resistance training result in hypertrophy, elicits increases in mitochondrial content and cross-sectional area of the fibres, and may change the fibre-type composition of the muscle towards a larger percentage of slow-type fibres. In contrast, changes in the opposite direction occur when neuromuscular activity is reduced, the muscle is immobilized in a shortened position, or paralysed. The broad range of stimuli that affect the properties of jaw muscles might help explain the large variability in the anatomical and physiological characteristics found among individuals, muscles, and muscle portions.

  17. Jaw avascular osteonecrosis after treatment of multiple myeloma with zoledronate.

    PubMed

    Lobato, J V; Maurício, A C; Rodrigues, J M; Cavaleiro, M V; Cortez, P P; Xavier, L; Botelho, C; Hussain, N Sooraj; Santos, J D

    2008-01-01

    of metastatic disease evaluated by biopsy. In these three described clinical cases, surgical debridment without flap elevation, intensive antibiotherapy and the suspension of the zoledronate treatment allowed a partial recovery of the patients. The purpose of this clinical report is to point out that patients suffering from multiple myeloma can develop bone osteonecrosis induced by treatment with bisphosphonates. Research to determine the mechanism of this dental phenomenon is needed to fully validate and substantiate the possible link between bisphosphonate treatment of multiple myeloma or other cancer diseases and avascular osteonecrosis of the jaws. Until then, clinicians involved in the care of patients at risk should consider this possible complication.

  18. Jaw-muscle fiber architecture in tufted capuchins favors generating relatively large muscle forces without compromising jaw gape.

    PubMed

    Taylor, Andrea B; Vinyard, Christopher J

    2009-12-01

    Tufted capuchins (sensu lato) are renowned for their dietary flexibility and capacity to exploit hard and tough objects. Cebus apella differs from other capuchins in displaying a suite of craniodental features that have been functionally and adaptively linked to their feeding behavior, particularly the generation and dissipation of relatively large jaw forces. We compared fiber architecture of the masseter and temporalis muscles between C. apella (n=12) and two "untufted" capuchins (C. capucinus, n=3; C. albifrons, n=5). These three species share broadly similar diets, but tufted capuchins occasionally exploit mechanically challenging tissues. We tested the hypothesis that tufted capuchins exhibit architectural properties of their jaw muscles that facilitate relatively large forces including relatively greater physiologic cross-sectional areas (PCSA), more pinnate fibers, and lower ratios of mass to tetanic tension (Mass/P(0)). Results show some evidence supporting these predictions, as C. apella has relatively greater superficial masseter and temporalis PCSAs, significantly so only for the temporalis following Bonferroni adjustment. Capuchins did not differ in pinnation angle or Mass/P(0). As an architectural trade-off between maximizing muscle force and muscle excursion/contraction velocity, we also tested the hypothesis that C. apella exhibits relatively shorter muscle fibers. Contrary to our prediction, there are no significant differences in relative fiber lengths between tufted and untufted capuchins. Therefore, we attribute the relatively greater PCSAs in tufted capuchins primarily to their larger muscle masses. These findings suggest that relatively large jaw-muscle PCSAs can be added to the suite of masticatory features that have been functionally linked to the exploitation of a more resistant diet by C. apella. By enlarging jaw-muscle mass to increase PCSA, rather than reducing fiber lengths and increasing pinnation, tufted capuchins appear to have

  19. Jaw-muscle fiber architecture in tufted capuchins favors generating relatively large muscle forces without compromising jaw gape

    PubMed Central

    Taylor, Andrea B.; Vinyard, Christopher J.

    2009-01-01

    Cebus apella is renowned for its dietary flexibility and capacity to exploit hard and tough objects. Cebus apella differs from other capuchins in displaying a suite of craniodental features that have been functionally and adaptively linked to their feeding behavior, particularly the generation and dissipation of relatively large jaw forces. We compared fiber architecture of the masseter and temporalis muscles between the tufted capuchin (C. apella; n = 12 ) and two “untufted” capuchins (C. capuchinus, n = 3; C. albifrons, n = 5). These three species share broadly similar diets, but tufted capuchins occasionally exploit mechanically challenging tissues. We tested the hypothesis that C. apella exhibits architectural properties of their jaw muscles that facilitate relatively large forces, including relatively greater physiologic cross-sectional areas (PCSA), more pinnate fibers, and lower ratios of mass to tetanic tension (Mass/P0). Results show some evidence supporting these predictions, as C. apella has relatively greater superficial masseter, whole masseter, and temporalis PCSAs, significantly so only for the temporalis following Bonferroni adjustment. Capuchins did not differ in pinnation angle or Mass/P0. As an architectural trade-off between maximizing muscle force and muscle excursion/contraction velocity, we also tested the hypothesis that C. apella exhibits relatively shorter muscle fibers. Contrary to our prediction, there are no significant differences in relative fiber lengths between tufted and untufted capuchins. Therefore, we attribute the relatively greater PCSAs in C. apella primarily to their larger muscle masses. These findings suggest that relatively large jaw-muscle PCSAs can be added to the suite of masticatory features that have been functionally linked to the exploitation of a more resistant diet by C. apella. By enlarging jaw-muscle mass to increase PCSA, rather than reducing fiber lengths and increasing pinnation, tufted capuchins appear

  20. Apodemes associated with limbs support serial homology of claws and jaws in Onychophora (velvet worms).

    PubMed

    de Sena Oliveira, Ivo; Mayer, Georg

    2013-10-01

    Although the onychophoran jaw blades are believed to be derivatives of foot claws, serial homology of these structures has not been demonstrated. To shed light on the evolutionary origin of the onychophoran jaws, we searched for morphological landmarks and compared the internal and external anatomy of jaws and distal leg portions in representatives of the two major onychophoran subgroups, the Peripatidae and Peripatopsidae. Our data revealed hitherto unknown structures associated with the onychophoran limbs, such as a soft diastemal membrane separating the anterior and posterior portions of the inner jaw blade (present only in Peripatidae), apodemes associated with feet, an eversible dorsal sac at the basis of each foot claw, and a specific arrangement of musculature associated with the sclerotised claws, jaws and their apodemes. Specific correspondences in structure and position of apodemes support serial homology of claws and jaws, suggesting that the onychophoran jaw evolved from the distal portion rather than the entire limb in the last common ancestor of Onychophora.

  1. Stage 0 osteonecrosis of the jaw in a patient on denosumab.

    PubMed

    Aghaloo, Tara L; Dry, Sarah M; Mallya, Sanjay; Tetradis, Sotirios

    2014-04-01

    Osteonecrosis of the jaws (ONJ) is a complex disease involving multiple tissue and cell-type responses to wound healing or infection. AAOMS defines bisphosphonate related ONJ (BRONJ) as exposed, necrotic bone in the maxillofacial region that has persisted for more than 8 weeks in a patient with current or previous antiresorptive treatment, without a history of radiation therapy to the jaws. Since the first reported ONJ cases in 2003 and 2004, there has been little advancement in understanding the etiology and pathophysiology of ONJ. Many hypotheses have been proposed, including bisphosphonate (BP) toxicity to oral epithelium, altered wound healing after tooth extraction, high turnover of the mandible and maxilla, oral biofilm formation, infection and inflammation, and suppression of angiogenesis and bone turnover. The current classification system of ONJ involves stages 0 to 3 and is based on patient clinical presentation. This report describes a case of stage 0 ONJ in a patient on denosumab and indicates the full-spectrum similarities between BP- and denosumab-associated ONJ clinically, radiographically, and histologically.

  2. Denosumab and osteonecrosis of the jaws - the pharmacology, pathogenesis and a report of two cases.

    PubMed

    O'Halloran, M; Boyd, N M; Smith, A

    2014-12-01

    Denosumab (Amgen, Thousand Oaks, California, USA) is a new bone antiresorptive agent used in patients with osteoporosis or metastatic cancer to the bones. As with the bisphosphonates that are used as antiresorptive medications, denosumab has been associated with osteonecrosis of the jaws (ONJ). Over the past two years there has been an increase in the literature describing ONJ in patients receiving agents such as denosumab. Due to promising study results that demonstrate the effectiveness of denosumab in avoiding skeletal complications related to osteoporosis and metastatic bone disease, more patients will receive denosumab in the future. It is reported that this has the potential to become a comparable challenge to bisphosphonate related osteonecrosis of the jaws (BRONJ) for clinicians. This article describes the management of two patients that developed ONJ while receiving denosumab, reviews the incidence of ONJ associated with denosumab, and contrasts the pharmacokinetics of denosumab and the bisphosphonates. The importance of avoiding interventional dental treatment until denosumab has been withdrawn for six months cannot be overstated. © 2014 Australian Dental Association.

  3. Genetic and environmental factors influencing tooth and jaw malformations in rabbits.

    PubMed

    Korn, A K; Brandt, H R; Erhardt, G

    2016-04-02

    Tooth alterations of 281 rabbits from 10 different breeds were evaluated, starting at the age of three weeks until they were fully grown. All rabbits were kept in an outdoor facility, fed with a pelleted diet and had free access to water and hay. The most common finding in 3182 clinical examinations was a gap between the mandibular incisors (38 per cent). Skull X-rays from 4 adult breeding rabbits, 15 offspring with clinical signs of dental disease and 12 clinically healthy siblings were assessed by two different methods using cephalometric distances and anatomical reference lines. Repeatabilities of cephalometric distances were mostly low and no significant associations to tooth health were found. The anatomical reference lines revealed dental findings even in rabbits that were graded as tooth healthy in previous clinical examinations. On the basis of the demonstrated age-dependent development of tooth and jaw malformations a first examination and selection at the age of 12 weeks can be recommended. Also genetic aspects for tooth and jaw malformations were considered. The estimated heritability for brachygnathia superior was 0.254 ± 0.169 for all examinations and 0.105 ± 0.092 comprising the last examination of each rabbit when fully grown. British Veterinary Association.

  4. Non-Radiation-Related Osteonecrosis of the Jaws in Dogs: 14 Cases (1996–2014)

    PubMed Central

    Peralta, Santiago; Arzi, Boaz; Nemec, Ana; Lommer, Milinda J.; Verstraete, Frank J. M.

    2015-01-01

    Osteonecrosis of the jaws (ONJ) is an entity of major clinical impact characterized by chronically exposed necrotic mandibular or maxillary bone. Its clinicopathological characteristics and possible inciting or risk factors are well described in humans but only anecdotally reported in dogs. Treatment modalities and outcome vary depending on the inciting factors involved and the extent and severity of the lesions. The objectives of this study were to retrospectively describe the clinicopathological features of non-radiation-related ONJ in a series of 14 dogs, identify possible inciting or risk factors, and report on the surgical treatment and outcome. For all patients, the medical records were used to collect information regarding signalment, clinical signs, characteristics of the oral, jaw and dental lesions, diagnostic imaging findings, histopathological and microbiological analysis, treatment performed, and outcome. The data collected showed that non-radiation-related ONJ appears to be an infrequent clinical entity but of significant impact in dogs; that a history of systemic antibiotics and dental disease is common among affected dogs; that previous dental extractions are commonly associated with ONJ sites; that using a systematic diagnostic approach is essential for diagnosis; and that thorough surgical debridement combined with a course of oral antibiotics was effective in the described dogs affected by advanced non-radiation-related ONJ. PMID:26664936

  5. Multiple Compond Odontomas in the Jaws: A Rare Case Report

    PubMed Central

    Sahni, Priya; Pereira, Treville; Zingade, Jyoti

    2015-01-01

    Odontomas are tumours of odontogenic origin. In these tumours both the epithelial and mesenchymal cells undergo differentiation to form enamel and dentin with variable amounts of cementum and pulp tissue. The odontomas represent a hamartoma rather than a neoplasm. When the enamel and dentin are laid down in an organized manner it is termed as a compound odontoma wherein the tumour forms a collection of small structures resembling teeth. On the other hand, an irregular mass with no similarity to teeth is termed as a complex odontoma. There are cases of extensive and multiple compound odontomas which have been identified in either of the jaws. The present case is rare with multiple compound odontomas involving both the jaws of 45-year-old male patient. A review of seven such cases reported so far has been presented. PMID:26816995

  6. The origin and early phylogenetic history of jawed vertebrates

    PubMed Central

    Brazeau, Martin D.; Friedman, Matt

    2015-01-01

    The focus of study for nearly two centuries1, fossils of early gnathostomes—or jawed vertebrates—yield key clues about the evolutionary assembly of the bodyplan common to the group, as well the divergence of the two living gnathostome lineages: the cartilaginous and bony fishes2,3. A series of remarkable new palaeontological discoveries4-10, analytical advances and innovative reinterpretations of old fossils11-14 have fundamentally altered a decades-old consensus on the relationships of extinct gnathostomes15,16, delivering a new evolutionary framework3,6,10-14 for exploring major questions which remain unanswered, including the origin of jaws17-19. PMID:25903631

  7. Jaw, blink and corneal reflex latencies in multiple sclerosis.

    PubMed Central

    Sanders, E A; Ongerboer de Visser, B W; Barendswaard, E C; Arts, R J

    1985-01-01

    Jaw, blink and corneal reflexes, which all involve the trigeminal system, were recorded in 54 patients with multiple sclerosis; thirty-seven of these patients were classified as having definite multiple sclerosis and 17 as indefinite multiple sclerosis, according to Schumacher's criteria. The jaw reflex was abnormal less frequently than either of the other two reflexes, but in four cases it was the only abnormal reflex found. Testing a combination of two or three trigeminal reflexes did not yield a higher incidence of abnormalities than testing the blink or corneal reflex alone. Nine patients showed abnormal reflexes which were unexpected on the basis of clinical symptoms. The combined recordings demonstrate at least one abnormal reflex in 74% of the patients. The various types of reflex abnormalities reflect major damage to different parts of the trigeminal system and may therefore make an important contribution to the diagnosis of multiple sclerosis. PMID:4087004

  8. Double lead spiral platen parallel jaw end effector

    NASA Technical Reports Server (NTRS)

    Beals, David C.

    1989-01-01

    The double lead spiral platen parallel jaw end effector is an extremely powerful, compact, and highly controllable end effector that represents a significant improvement in gripping force and efficiency over the LaRC Puma (LP) end effector. The spiral end effector is very simple in its design and has relatively few parts. The jaw openings are highly predictable and linear, making it an ideal candidate for remote control. The finger speed is within acceptable working limits and can be modified to meet the user needs; for instance, greater finger speed could be obtained by increasing the pitch of the spiral. The force relaxation is comparable to the other tested units. Optimization of the end effector design would involve a compromise of force and speed for a given application.

  9. Sunitinib related osteonecrosis of jaw: a case report.

    PubMed

    Fleissig, Yoram; Regev, Eran; Lehman, Hadas

    2012-03-01

    A 58-year-old woman presented to the Oral and Maxillofacial Surgery Clinic experiencing severe limited mouth opening and exposed bone in the socket of the right mandibular third molar 8 months following the extraction of the tooth. The patient had been treated during the year before her presentation with sunitinib, an antiangiogenic drug, for renal cell carcinoma. The clinical, radiographic, and histologic picture of a chronic nonhealing extraction socket was consistent with osteonecrosis of the jaw (ONJ), although she had never been treated with bisphosphonates or corticosteroids. The treatment with sunitinib was discontinued and the patient was treated with antibiotics and physiotherapy for 12 weeks with complete recovery. Sunitinib may cause osteonecrosis of the jaw after oral surgical interventions with no previous exposure to bisphosphonates. The pathogenesis may be related to its antiangiogenic mechanism and impaired wound healing. Full recovery may require long-term cessation of the insulting drug combined with prolonged antibiotic treatment.

  10. The earliest herbivorous marine reptile and its remarkable jaw apparatus

    PubMed Central

    Chun, Li; Rieppel, Olivier; Long, Cheng; Fraser, Nicholas C.

    2016-01-01

    Newly discovered fossils of the Middle Triassic reptile Atopodentatus unicus call for a radical reassessment of its feeding behavior. The skull displays a pronounced hammerhead shape that was hitherto unknown. The long, straight anterior edges of both upper and lower jaws were lined with batteries of chisel-shaped teeth, whereas the remaining parts of the jaw rami supported densely packed needle-shaped teeth forming a mesh. The evidence indicates a novel feeding mechanism wherein the chisel-shaped teeth were used to scrape algae off the substrate, and the plant matter that was loosened was filtered from the water column through the more posteriorly positioned tooth mesh. This is the oldest record of herbivory within marine reptiles. PMID:27386529

  11. Zoledronate and other risk factors associated with osteonecrosis of the jaw in cancer patients: a case-control study

    PubMed Central

    Wessel, John H.; Dodson, Thomas B.; Zavras, Athanasios I.

    2008-01-01

    Background Bisphosphonates (BPs) effectively treat metastatic bone disease, hypercalcaemia, and osteoporosis. BP exposure, however, may be associated with osteonecrosis of the jaws (ONJ). The aim of the present study was to estimate the magnitude of the association between intravenous BP exposure and ONJ, and to identify potential confounders. Methods Using a case-control study design, the investigators identified a sample of cases with ONJ and randomly matched them with five controls per case. The controls were matched to cases on age, sex, cancer type, and date of cancer diagnosis. The medical records were abstracted and data on BP exposure, cancer therapy and comorbidities were recorded. Statistical analyses were performed using conditional logistic regression in Stata 9.0. Results Thirty cases of osteonecrosis of the jaw (ONJ) were identified at Massachusetts General Hospital from February 2003 through February 2007. Zoledronate was found to confer significant risk towards development of ONJ (adjusted odds ratio = 31.8, p < 0.05). While a trend towards increased risk was noted for pamidronate, this association was not significant after controlling for zoledronate. Obesity, smoking, and metastasis were significantly associated with ONJ development, whereas oral bisphosphonates had no effect. Conclusion In this study, cancer patients who had received zoledronate exhibited a significant 30-fold increase in their risk to develop osteonecrosis of the jaw. More studies are needed to elucidate the exact role of obesity and smoking in the development of ONJ, and the complex interactions of IV bisphosphonates with other chemotherapies during cancer treatment. PMID:18355585

  12. Description of the lower jaws of Baculites from the Upper Cretaceous U.S. Western Interior

    NASA Astrophysics Data System (ADS)

    Larson, Neal L.; Landman, Neil H.

    2017-03-01

    We report the discovery of lower jaws of Baculites (Ammonoidea) from the Upper Cretaceous U.S. Western Interior. In the lower Campanian Smoky Hill Chalk Member of the Niobrara Chalk of Kansas, most of the jaws occur as isolated elements. Based on their age, they probably belong to Baculites sp. (smooth). They conform to the description of rugaptychus, and are ornamented with coarse rugae on their ventral side. One specimen is preserved inside a small fecal pellet that was probably produced by a fish. Another specimen occurs inside in a crushed body chamber near the aperture and is probably in situ. Three small structures are present immediately behind the jaw and may represent the remains of the gills. In the lower Maastrichtian Pierre Shale of Wyoming, two specimens of Baculites grandis contain lower jaws inside their body chambers, and are probably in situ. In both specimens, the jaws are oriented at an acute angle to the long axis of the shell, with their anterior ends pointing toward the dorsum. One of the jaws is folded into a U-shape, which probably approximates the shape of the jaw during life. Based on the measurements of the jaws and the shape of the shell, the jaws could not have touched the sides of the shell even if they were splayed out, implying that they could not have effectively served as opercula. Instead, in combination with the upper jaws and radula, they constituted the buccal apparatus that collected and conveyed food to the esophagus.

  13. Electrophysiological analysis of rhythmic jaw movements in the freely moving mouse.

    PubMed

    Kobayashi, Masayuki; Masuda, Yuji; Fujimoto, Yoshiyuki; Matsuya, Tokuzo; Yamamura, Kensuke; Yamada, Yoshiaki; Maeda, Norihiko; Morimoto, Toshifumi

    2002-03-01

    Although rhythmic jaw movement in feeding has been studied in mammals, such as rats, rabbits and monkeys, the cellular and molecular mechanisms underlying it are not well understood. Transgenic and gene-targeting technologies enable direct control of the genetic makeup of the mouse, and have led to the development of a new category of reagents that have the potential to elucidate the cellular and molecular mechanisms of neural networks. The present study attempts to characterize rhythmic jaw movements in the mouse and to demonstrate its relevance to rhythmic jaw movements found in higher mammals using newly developed jaw-tracking systems and electromyograms of the masticatory muscles. The masticatory sequence of the mouse during feeding was classified into two stages, incision and chewing. Small and rapid (8 Hz) open-close jaw movements were observed during incision, while large and slow (5 Hz) open-close jaw movements were observed during chewing. Integrated electromyograms of the masseteric and digastric muscles were larger during chewing than those observed during incision. Licking behavior was associated with regular (8 Hz), small open-close jaw movements with smaller masseteric activity than those observed during mastication. Grooming showed variable patterns of jaw movement and electromyograms depending on the grooming site. These results suggest that there are neuronal mechanisms producing different frequencies of rhythmic jaw movements in the mouse, and we conclude that the mouse is useful for understanding rhythmic jaw movements in higher mammals.

  14. Gum chewing and jaw muscle fatigue and pains.

    PubMed

    Christensen, L V; Tran, K T; Mohamed, S E

    1996-06-01

    To study possible associations between gum chewing and fatigue and pains in the jaw muscles, eight healthy adults performed prolonged idling, prolonged unilateral chewing of gum, and brief vigorous clenching of the teeth (MVC). Through surface electromyography (EMG), the authors monitored the cumulative (microV.s) as well as the average rates (microV.s-1) of contractile activities in the right and left masseter muscles. During 10 min of idling there was an absence of muscle fatigue and muscle pains when the EMG rates of the right and left masseter muscles were 2% and 3%, respectively, of those required to elicit isometric muscle pains through MVC. During 10 min of right-sided gum chewing at a rate of 1.2 Hz, the majority of subjects (75%) experienced weak jaw muscle fatigue-not jaw muscle pains-when the EMG rates of the right and left masseter muscles were 38% and 19%, respectively, of those required to elicit isometric pains through MVC. In comparison with 10 min of idling, the weak muscle fatigue of 10 min of unilateral gum chewing appeared when the total contractile activities of the right and left masseter muscles were increased by 1664% and 519%, respectively. It seemed as if prolonged unilateral gum chewing and previous pain-releasing MVC caused some sensitization of muscle nociceptors which, in turn, aggravated subsequent isometric jaw muscle pains elicited through MVC. Even though the right masseter muscle was the most frequent site of clinical fatigue and pains, the authors found no evidence supporting the theoretical foundation of the myofascial pain/dysfunction syndrome.

  15. Pharmacologic modalities in the treatment of osteoradionecrosis of the jaw.

    PubMed

    McCaul, James Anthony

    2014-05-01

    Managing osteoradionecrosis (ORN) of the facial bones is a challenge in maxillofacial head and neck surgery. Changes in understanding of ORN of the jaws has led to new studies using novel therapeutic modalities to manage this disorder. These treatment regimens may allow medical management to replace major reconstructive surgery for some patients who have already undergone chemoradiotherapy or combined modality therapy for head and neck cancer.

  16. An Endocrine Jaw Lesion: Dentist Perspective in Diagnosis

    PubMed Central

    Kalapala, Lavanya; Babburi, Suresh; Venigalla, Aparna; Pinisetti, Soujanya; Ganipineni, Kiranmai

    2016-01-01

    Brown tumor is a rare nonneoplastic focal giant cell lesion that occurs in hyperparathyroidism patients with a prevalence rate of 0.1% in jaws. We report an extremely rare case of brown tumor in mandible of a 40-year-old female patient that presented as the first clinical manifestation of hyperparathyroidism. Dentist played a pivotal role in the present case by the early diagnosis of lesion and its intervention. PMID:27974979

  17. Bisphosphonates and jaw osteonecrosis in patients with advanced breast cancer.

    PubMed

    Sanna, G; Preda, L; Bruschini, R; Cossu Rocca, M; Ferretti, S; Adamoli, L; Verri, E; Franceschelli, L; Goldhirsch, A; Nolè, F

    2006-10-01

    In recent years, several cases of mandibular necrosis associated with long-term use of bisphosphonates have been reported. The estimated incidence varies from 1% to 4.6%. We conducted an observational study with the aim of determining the incidence of jaw osteonecrosis in advanced breast cancer patients with bone metastases under bisphosphonate treatment and to identify subjects at higher risk of developing this complication evaluating preclinical signs. We considered two groups of patients. All the patients complaining of odontostomatological symptoms underwent maxillary CT scan and maxillo-surgeon clinical examination. Asymptomatic patients were asked to perform a standard orthopantomography (OPT). From February 2005 to October 2005, we observed five patients with jaw bone necrosis (6%). Diagnosis was radiological and clinical. In two patients a confirmatory biopsy was performed. In the same time interval, OPTs were collected from 76 asymptomatic patients. Three OPTs revealed radiological features of suspicious mandibular necrosis. Maxillary CT scan confirmed the presence of an osteolityc area with signs of periosteal reaction. All the three patients were referred to maxillo-surgeon and two out of three patients underwent mandibular biopsy, but histopathological results were not conclusive. In our experience, the incidence of jaw bone necrosis in breast cancer patients seems to be higher than in other reports (6%). Radiological features of suspicious jaw necrosis were observed in three asymptomatic patients. We do not know how these findings should be considered. Anyway, standard OPT is a simple procedure, and may allow identification of periodontal conditions that in some way can predispose to the development of this uncommon event.

  18. Interactions between the jaw-opening reflex and mastication.

    PubMed

    Lund, J P; Rossignol, S; Murakami, T

    1981-07-01

    Electrical stimulation of the anterior hard palate or upper lip was used to evoke the jaw-opening reflex in rabbits lightly anesthetized with urethane. The amplitude of each excitatory response recorded in the digastric electromyogram during mastication was compared with the mean amplitude of 10 prior control responses. When weak stimuli were used, the mean amplitude of the reflex dropped markedly during mastication and was smallest when the digastric muscle was inactive (closing and occlusal phases of the masticatory cycle). As the stimulus strength was increased, the size of the response during closing rose progressively until it exceeded values obtained during the control period or the jaw-opening phase. In addition, strong stimuli altered the total cycle length and the duration and amplitude of muscle activity in a phase-dependent manner. Stimuli given during closing were particularly effective in causing inhibition of jaw-closing muscle activity and in reducing the velocity and amplitude of closure. It is concluded that the cyclical gain changes of the reflex response to noxious stimuli are controlled to a large extent by premotoneuronal mechanisms and that the overall effect on the masticatory cycle structure is phase dependent.

  19. The feasibility of immediately loading dental implants in edentulous jaws.

    PubMed

    Henningsen, Anders; Smeets, Ralf; Wahidi, Aria; Kluwe, Lan; Kornmann, Frank; Heiland, Max; Gerlach, Till

    2016-08-01

    Immediate loading of dental implants has been proved to be feasible in partially edentulous jaws. The purpose of this retrospective investigation was to assess the feasibility of immediately loading dental implants in fully edentulous jaws. A total of 24 patients aged between 53 and 89 years received a total of 154 implants in their edentulous maxillae or mandibles. Among the implants, 45 were set in fresh extracted sockets and 109 in consolidated alveolar bones. The implants were provisionally managed with chair-side made provisional resin bridges and exposed to immediate loading. Implants were followed up for 1-8 years, including radiographic imaging. Marginal bone levels were evaluated based on radiographic imaging. A total of 148 out of the 154 implants survived over the follow-up period of 1 to 8 years, giving a survival rate of 96%. The time or region of the implantation, the pre-implant augmentation, and the length and diameter of the implants had no statistically significant influence on the survival or the success rate. The marginal bone level remained stable with only minimal loss of 0.3 mm after 60 months of loading. Within the limitations of this study, immediate loading is feasible for dental implants in edentulous jaws.

  20. Midsagittal jaw movements as a sleep/wake marker.

    PubMed

    Senny, Frédéric; Destiné, Jacques; Poirrier, Robert

    2009-02-01

    The seriousness of the Obstructive Sleep Apnea/Hypopnea Syndrome is measured by the apnea-hypopnea index (AHI), the number of sleep apneas and hypopneas over the total sleep time (TST). Cardiorespiratory signals are used to detect respiratory events while the TST is usually assessed by the analysis of electroencephalogram traces in polysomnography (PSG) or wrist actigraphy trace in portable monitoring. This paper presents a sleep/wake automatic detector that relies on a wavelet-based complexity measure of the midsagittal jaw movement signal and multilayer perceptrons. In all, 63 recordings were used to train and test the method, while 38 recordings constituted an independent evaluation set for which the sensitivity, the specificity, and the global agreement of sleep recognition, respectively, reached 85.1%, 76.4%, and 82.9%, compared with the PSG data. The AHI computed automatically and only from the jaw movement analysis was significantly improved (p < 0.0001) when considering this sleep/wake detector. Moreover, a sensitivity of 88.6% and a specificity of 83.6% were found for the diagnosis of the sleep apnea syndrome according to a threshold of 15. Thus, the jaw movement signal is reasonably accurate in separating sleep from wake, and, in addition to its ability to score respiratory events, is a valuable signal for portable monitoring.

  1. Bisphosphonates and osteonecrosis of the jaw--current thoughts.

    PubMed

    Arrain, Yazdana; Masud, Tahir

    2009-09-01

    Bisphosphonates are increasingly being used in a number of bone conditions, including osteoporosis and metastatic cancer. As a consequence, the reported cases of bisphosphonate-related osteonecrosis of the jaw (BONJ) have increased. BONJ remains rare in patients being treated for osteoporosis, but is commoner in cancer patients where the bisphosphonate doses are much higher and mode of delivery is intravenous. Recently, much more is known about classification and mode of action of the bisphosphonates. The potency of the various nitrogen-containing bisphosphonates is dependent on a number of factors including bone binding, zeta potential and inhibition of the enzyme farnesyl pyrophosphate synthase. There is current debate on why BONJ affects the jaw, particularly in relation to whether the jaw has high bone turnover or not. More is being learnt about the micro-organisms involved in the pathogenesis of BONJ and there is increasing evidence on the role of surgical treatment of this disabling condition. Dentists should be aware of the association of bisphosphonates and BONJ. This paper provides recent knowledge on bisphosphonate action, pathogenesis of BONJ and its treatment.

  2. Computer Simulation Methods for Crushing Process in an Jaw Crusher

    NASA Astrophysics Data System (ADS)

    Il'ich Beloglazov, Ilia; Andreevich Ikonnikov, Dmitrii

    2016-08-01

    One of the trends at modern mining enterprises is the application of combined systems for extraction and transportation of the rock mass. Given technology involves the use the conveyor lines as a continuous link of combined technology. The application of a conveyor transport provides significant reduction of costs for energy resources, increase in labor productivity and process automation. However, the use of a conveyor transport provides for certain requirements for the quality of transported material. The maximum size of the rock mass pieces is one of the basic parameters for it. The crushing plants applies as a coarse crushing followed by crushing the material to the maximum size of piece which possible to use for conveyor transport. It is often represented by jaw crushers. Modelling of crushing process in jaw crushers allows to maximally optimize workflow and increase efficiency of the equipment at the further transportation and processing of rocks. We studied the interaction between walls of the jaw crusher and bulk material by using discrete element method (DEM) in this paper. The article examines the process of modeling by stages. It includes design of the crusher construction in solid and surface modeling system. Modelling of the crushing process based on the experimental data received via the crushing unit BOYD. The process of destruction and particle size distribution in the study was done. Analysis of research results shows a comparability of actual experiment and modeling process.

  3. Osteosarcoma of the jaws: demographic and CT imaging features

    PubMed Central

    Wang, S; Shi, H; Yu, Q

    2012-01-01

    Objective The aim of this study was to evaluate the patient demographic and CT imaging findings of primary osteosarcoma of the jaws. Methods 88 primary osteosarcomas of the jaws histopathologically diagnosed during 1997–2007 were reviewed. 21 cases of CT images were reviewed. Results Of 88 patients, 51 (58%) had tumours in the mandible and 37 (42%) in the maxilla. The mean age was 37.8 years (range 9–80 years). The male-to-female ratio was 1.32:1. The mean age of patients with mandibular lesions was 41.04 years and in those with maxillary lesions it was 33.3 years. CT imaging findings were available in 21 patients. In the maxilla (n = 9), all tumours (100%) arose from the alveolar ridge. In the mandible (n = 12), most tumours (9 cases, 75%), arose from the ramus and/or condyle. All except two lesions had the epicentrum within the medullary cavity of the involved bone. The presence of periosteal reaction was demonstrated in 13 cases (62%). Soft-tissue extension was present in 18 lesions (86%), with calcification identified in 13 (72%). Conclusions This study provides age, sex distribution, location and CT imaging features of primary osteosarcoma of the jaws. PMID:22074870

  4. Bisphosphonate-induced osteonecrosis of the jaw: a medical enigma?

    PubMed

    Siddiqi, Allauddin; Payne, Alan G T; Zafar, Sobia

    2009-09-01

    Bisphosphonates are used for the standard of care of patients with skeletal metastases and hypocalcemia of malignancy. Bisphosphonate-induced osteonecrosis (BION) is a serious complication. Clinically, BION presents as an area of exposed alveolar bone that occurs spontaneously or becomes evident following an invasive surgical procedure such as extraction of a tooth, periodontal surgery, apicoectomy, or oral implant placement. The mechanism by which bisphosphonates cause osteonecrosis is uncertain. There are no controlled trials to show a direct cause-effect relationship between bisphosphonates and osteonecrosis of the jaw. Oral bisphosphonate-induced necrosis is a rare clinical entity, less frequent, less aggressive, more predictable, and more responsive to treatment than IV forms of bisphosphonate-related osteonecrosis of the jaw. However, there have been reports of this complication with the less potent oral forms of bisphosphonates (0.007% to 0.01%). The morbidity of osteonecrosis of the jaw induced by IV bisphosphonates is significant, so prevention should receive prime importance. Patients should receive prophylactic dental examinations, and any necessary dental treatment before starting bisphosphonate therapy. Good communication among dentists, oral surgeons, physicians, and oncologists is of vital importance in providing care of these patients.

  5. Scaling and Accommodation of Jaw Adductor Muscles in Canidae

    PubMed Central

    Kemp, Graham J.; Jeffery, Nathan

    2016-01-01

    ABSTRACT The masticatory apparatus amongst closely related carnivoran species raises intriguing questions about the interplay between allometry, function, and phylogeny in defining interspecific variations of cranial morphology. Here we describe the gross structure of the jaw adductor muscles of several species of canid, and then examine how the muscles are scaled across the range of body sizes, phylogenies, and trophic groups. We also consider how the muscles are accommodated on the skull, and how this is influenced by differences of endocranial size. Data were collected for a suite of morphological metrics, including body mass, endocranial volume, and muscle masses and we used geometric morphometric shape analysis to reveal associated form changes. We find that all jaw adductor muscles scale isometrically against body mass, regardless of phylogeny or trophic group, but that endocranial volume scales with negative allometry against body mass. These findings suggest that head shape is partly influenced by the need to house isometrically scaling muscles on a neurocranium scaling with negative allometry. Principal component analysis suggests that skull shape changes, such as the relatively wide zygomatic arches and large sagittal crests seen in species with higher body masses, allow the skull to accommodate a relative enlargement of the jaw adductors compared with the endocranium. Anat Rec, 299:951–966, 2016. © 2016 The Authors The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology Published by Wiley Periodicals, Inc. PMID:27103346

  6. Evolution of the vertebrate jaw from developmental perspectives.

    PubMed

    Kuratani, Shigeru

    2012-01-01

    Attainment of the biting jaw is regarded as one of the major novelties in the early history of vertebrates. Based on a comparison between lamprey and gnathostome embryos, evolutionary developmental studies have tried to explain this novelty as changes in the developmental patterning of the mandibular arch, the rostralmost pharyngeal arch, at the molecular and cellular levels. On the other hand, classical theories in the field of comparative morphology assumed the involvement of hypothetical premandibular arch(es) that ancestral animals would have possessed rostral to the mandibular arch, in the transition from agnathan to gnathostome states. These theories are highly biased toward the segmental scheme of the vertebrate head, and the concept of premandibular "arches" is no longer accepted by the current understanding. Instead, the premandibular domain has now become of interest in the understanding of cranial development, especially in its rostral part. As newer theories that consider involvement of the premandibular domain, the neoclassical and heterotopy theories are here compared from evolutionary developmental perspectives, in conjunction with the development of nasal and hypophyseal placodes, in the context of the evolutionary acquisition of the jaw. Given recent advances in understanding of the lamprey development, evolution of the Dlx code is also discussed together with the evolutionary scenario of jaw acquisition. © 2012 Wiley Periodicals, Inc.

  7. A comparison of cephalometric analyses for assessing sagittal jaw relationship.

    PubMed

    Gul-e-Erum; Fida, Mubassar

    2008-11-01

    To compare the seven methods of cephalometric analysis for assessing sagittal jaw relationship and to determine the level of agreement between them. Cross-sectional, analytical study. Dental Section, the Aga Khan University Hospital, Karachi, from January to December 2004. Seven methods, describing anteroposterior jaw relationships (A-B plane, ANB, Wits, AXB, AF-BF, FABA and Beta angle) were measured on the lateral cephalographs of 85 patients. Correlation analysis, using Cramer's V-test, was performed to determine the possible agreement between the pair of analyses. The mean age of the sample, comprising 35 males and 50 females was 15 years and 3 months. Statistically significant relationships were found among seven sagittal parameters with p-value < 0.001. Very strong correlation was found between AXB and AF-BF distance (r=0.924); and weak correlation between ANB and Beta angle (r=0.377). Wits appraisal showed the greatest coefficient of variability. Despite varying strengths of association, statistically significant correlations were found among seven methods for assessing sagittal jaw relationship. FABA and A-B plane may be used to predict the skeletal class in addition to the established ANB angle.

  8. The feasibility of immediately loading dental implants in edentulous jaws

    PubMed Central

    2016-01-01

    Purpose Immediate loading of dental implants has been proved to be feasible in partially edentulous jaws. The purpose of this retrospective investigation was to assess the feasibility of immediately loading dental implants in fully edentulous jaws. Methods A total of 24 patients aged between 53 and 89 years received a total of 154 implants in their edentulous maxillae or mandibles. Among the implants, 45 were set in fresh extracted sockets and 109 in consolidated alveolar bones. The implants were provisionally managed with chair-side made provisional resin bridges and exposed to immediate loading. Implants were followed up for 1–8 years, including radiographic imaging. Marginal bone levels were evaluated based on radiographic imaging. Results A total of 148 out of the 154 implants survived over the follow-up period of 1 to 8 years, giving a survival rate of 96%. The time or region of the implantation, the pre-implant augmentation, and the length and diameter of the implants had no statistically significant influence on the survival or the success rate. The marginal bone level remained stable with only minimal loss of 0.3 mm after 60 months of loading. Conclusions Within the limitations of this study, immediate loading is feasible for dental implants in edentulous jaws. PMID:27588213

  9. Function of a key morphological innovation: fusion of the cichlid pharyngeal jaw

    PubMed Central

    Darrin Hulsey, C

    2005-01-01

    The pharyngeal jaw of cichlids may represent a key innovation that facilitated their unparalleled trophic divergence. In cichlids, ‘fusion’ of the lower pharyngeal jaw (LPJ) results from suturing between the two lower ceratobranchials. To examine, what novel abilities a more extensively fused pharyngeal jaw may confer, the function of LPJ suturing was examined in Heroine cichlids. Greater LPJ suturing, pharyngeal jaw splitting under compression and the forces used to crush molluscs in the wild suggest increased LPJ fusion in the trophically polymorphic Herichthys minckleyi operates to strengthen the pharyngeal jaw. Among Heroine cichlid species, the presence of an external LPJ suture and feeding specialization on molluscs was evolutionarily quite variable, but greater LPJ fusion estimated from the amount of external suturing was highly correlated with molluscivory. Throughout cichlid diversification, increased pharyngeal jaw fusion via suturing has likely helped to reinforce the LPJ during pharyngeal processing thereby facilitating the ability of cichlids to exploit durable prey. PMID:16608685

  10. Association of dental and periodontal status with bisphosphonate-related osteonecrosis of the jaws. A retrospective case controlled study.

    PubMed

    Kos, Marcin

    2014-02-24

    To assess the association of oral hygiene, dental caries, and periodontal status with bisphosphonate-related osteonecrosis of the jaws. A retrospective case-control study on 81 patients treated for neoplasms with bone metastases. Twenty-nine patients with bone necrosis and 52 controls treated with bisphosphonates were compared using the Oral Hygiene Index, Decay, Missing, Filled Teeth, Community Periodontal Index of Treatment Needs, and Residual Periodontal Bone. The null hypothesis stated that there was no difference in parameters of oral health between patients with and without bone necrosis. Differences of means of above-mentioned variables were compared between the groups with Student's t-test or Mann-Whitney rank sum test and χ(2) test. Value of p ≤ 0.05 was considered significant. Poorer oral hygiene (OHIs 1.94 vs. 1.32; p = 0.065), more advanced dental caries (DMFT 26.85 vs. 22.87; p = 0.05), and more advanced periodontal disease (CPITN: = 0: 21.05% vs. 42.51%; = 1 13.16% vs. 7.29%; = 2: 0% vs. 15.38%; = 3: 65.79% vs. 28.34%; = 4: 0% vs. 6.48%, Residual periodontal bone 73.1% vs. 80.51%; p = 0,001) were characteristic of patients with bisphosphonate related jaw necrosis when compared with control group. An advanced dental caries or periodontal disease required surgical intervention which directly contributed to the development of the bone necrosis. Dental and periodontal disease can lead to bisphosphonate-related osteonecrosis of the jaw. Oncologic patients treated with bisphosphonates should be offered preventive care to reduce dental plaque, calculus, dental caries, and periodontal disease.

  11. Efficacy of the Dynamic Jaw Mode in Helical Tomotherapy With Static Ports for Breast Cancer

    PubMed Central

    Manabe, Yoshihiko; Hayashi, Akihiro; Murai, Taro; Takaoka, Taiki; Hattori, Yukiko; Iwata, Hiromitsu; Takenaka, Ran; Shibamoto, Yuta

    2015-01-01

    The recently developed dynamic jaw technology of tomotherapy can reduce craniocaudal dose spread without much prolonging the treatment time. This study aimed to investigate the efficacy of the dynamic jaw mode for tomotherapy of breast cancer. Static tomotherapy plans of the whole breast and supraclavicular regional lymph nodes, and plans for the whole breast only were generated in 25 patients with left-sided breast cancer. Plans with a field width of 2.5 or 5 cm with the dynamic or fixed jaw modes were made for each patient. The prescribed dose was 50 Gy in 25 fractions. In whole breast and supraclavicular nodal radiotherapy, dose distributions and homogeneity of the planning target volume (PTV) with the dynamic jaw mode were slightly inferior to those with the fixed jaw mode with a 5-cm field width (P < .05). However, lung low-dose volumes and mean doses of the larynx, thyroid, skin, and all the healthy tissues combined were smaller with the dynamic jaw mode than with the fixed jaw mode with a 5-cm field width (P < .001). In whole breast radiotherapy, mean doses of the skin and healthy tissues were lower with the dynamic jaw mode than with the fixed jaw mode with a 5-cm field width (P < .001) without significant differences in PTV dose distributions, homogeneity, and conformity. The dynamic jaw mode provided better sparing of organs at risks with minimal disturbance of dose–volume indices of PTV. Considering the treatment time, the 5-cm-field dynamic jaw mode is more efficient than the 2.5-cm fixed jaw mode. PMID:25398681

  12. A comparative study of identical VMAT plans with and without jaw tracking technique.

    PubMed

    Wu, Hao; Jiang, Fan; Yue, Haizhen; Hu, Qiaoqiao; Zhang, Jian; Liu, Zhuolun; Gong, Jian; Li, Sha; Geng, Jianhao; Zhang, Yibao

    2016-09-08

    The unwanted radiation transmission through the multileaf collimators could be reduced by the jaw tracking technique which is commercially available on Varian TrueBeam accelerators. On the basis of identical plans, this study aims to investigate the dosimetric impact of jaw tracking on the volumetric-modulated arc therapy (VMAT) plans. Using Eclipse treatment planning system (TPS), 40 jaw-tracking VMAT plans with various tumor volumes and shapes were optimized. Fixed jaw plans were created by editing the jaw coordinates of the jaw-tracking plans while other parameters were identical. The deliverability of this artificial modification was verified using COMPASS system via three-dimentional gamma analysis between the measurement-based reconstruction and the TPS-calculated dose distribution. Dosimetric parameters of dose-volume histogram (DVH) were compared to assess the improvement of dose sparing for organs at risk (OARs) in jaw-tracking plans. COMPASS measurements demonstrated that over 96.9% of structure volumes achieved gamma values less than 1.00 at criteria of 3 mm/3%. The reduction magnitudes of maximum and mean dose to various OARs ranged between 0.06% ~ 6.76% (0.04 ~ 7.29 Gy) and 0.09% ~ 7.81% (0.02 ~ 2.78 Gy), respectively, using jaw tracking, agreeing with the disparities of radiological characteristics between MLC and jaws. Jaw tracking does not change the delivery efficiency and total monitor units. The dosimetric comparison of VMAT plans with and without jaw tracking confirms the physics hypotheses that reduced transmission through tracking jaws will reduce doses to OARs without sacrificing the target dose coverage because it is meant to be covered by radiation beams going through the opening. © 2016 The Authors.

  13. Modulation of jaw reflexes induced by noxious stimulation to the muscle in anesthetized rats.

    PubMed

    Kurose, Masayuki; Yamamura, Kensuke; Noguchi, Makiko; Inoue, Makoto; Ootaki, Sachiko; Yamada, Yoshiaki

    2005-04-11

    Previous studies have shown that jaw reflexes and activity patterns of the jaw muscles were modulated in the presence of jaw muscle pain. However, there is no study comparing the modulatory effects on the jaw reflexes induced by noxious stimulation to the jaw muscle. To clarify this, effects of the application of mustard oil (MO), an inflammatory irritant, into the temporalis (jaw-closing) muscle on (1) jaw-opening reflex evoked by tooth pulp stimulation (TP-evoked JOR) as a nociceptive reflex, (2) jaw-opening reflex evoked by inferior alveolar nerve stimulation as a non-nociceptive reflex and (3) jaw-closing reflex evoked by trigeminal mesencephalic nucleus stimulation as a proprioceptive reflex were investigated in anesthetized rats. The MO application induced suppression of all reflexes, and the effect on the TP-evoked JOR was more prominent than on the other reflexes. To elucidate the involvement of endogenous opioid system for the suppressive effect, a systemic administration of naloxone following the MO application was conducted. The MO-induced suppressive effect on the TP-evoked JOR was reversed by the naloxone administration. The results suggest that noxious stimulation to the jaw muscle modulate jaw reflexes particularly for the nociceptive jaw-opening reflex, and the modulatory effect includes both facilitatory and inhibitory aspects. The results also suggest that pain modulatory systems such as the endogenous opioid system play a crucial role in the suppression of the nociceptive transmissions related to nociceptive reflexes, and in some pathological states, defense reflexes may not be evoked properly.

  14. A comparative study of identical VMAT plans with and without jaw tracking technique.

    PubMed

    Wu, Hao; Jiang, Fan; Yue, Haizhen; Hu, Qiaoqiao; Zhang, Jian; Liu, Zhuolun; Gong, Jian; Li, Sha; Geng, Jianhao; Zhang, Yibao

    2016-09-01

    The unwanted radiation transmission through the multileaf collimators could be reduced by the jaw tracking technique which is commercially available on Varian TrueBeam accelerators. On the basis of identical plans, this study aims to investigate the dosimetric impact of jaw tracking on the volumetric-modulated arc therapy (VMAT) plans. Using Eclipse treatment planning system (TPS), 40 jaw-tracking VMAT plans with various tumor volumes and shapes were optimized. Fixed jaw plans were created by editing the jaw coordinates of the jaw-tracking plans while other parameters were identical. The deliverability of this artificial modification was verified using COMPASS system via three-dimentional gamma analysis between the measurement-based reconstruction and the TPS-calculated dose distribution. Dosimetric parameters of dose-volume histogram (DVH) were compared to assess the improvement of dose sparing for organs at risk (OARs) in jaw-tracking plans. COMPASS measurements demonstrated that over 96.9% of structure volumes achieved gamma values less than 1.00 at criteria of 3 mm/3%. The reduction magnitudes of maximum and mean dose to various OARs ranged between 0.06%∼6.76%(0.04∼7.29 Gy) and 0.09%∼7.81%(0.02∼2.78 Gy), respectively, using jaw tracking, agreeing with the disparities of radiological characteristics between MLC and jaws. Jaw tracking does not change the delivery efficiency and total monitor units. The dosimetric comparison of VMAT plans with and without jaw tracking confirms the physics hypotheses that reduced transmission through tracking jaws will reduce doses to OARs without sacrificing the target dose coverage because it is meant to be covered by radiation beams going through the opening. PACS number(s): 87.55.de, 87.55.dk.

  15. Built to fight: variable loading conditions and stress distribution in stag beetle jaws.

    PubMed

    Goyens, Jana; Dirckx, Joris; Aerts, Peter

    2015-07-02

    Designing very robust structures in an efficient way is a reoccurring challenge in engineering. For male stag beetle weaponry, the solution to this problem was evolved by natural and sexual selection. Stag beetle armature is adapted to perform under extreme circumstances: male stag beetles fight pugnacious battles over females, by using their extremely large jaws as ferocious weapons. During violent encounters, these jaws have to withstand forces with a wide range of unpredictable directions at several application points. We constructed 1020 finite element models with different input forces to investigate how the male jaws are structurally adapted to avoid failure. The cross-sectional shape of the jaw is adapted to provide robustness against the reaction forces of biting. Nevertheless, the jaw's shape cannot prevent the fact that bite forces induce relatively high material stresses compared to other force directions. Also, males do not confine themselves in combats to bite with the most robust jaw regions. Both observations emphasize the usefulness of bite force modulation to avoid jaw failure. This is likely effectuated by a sensory network in the jaw exoskeleton, as sensor densities are nicely correlated to the maximal material stress caused by 510 different loading directions. Probably, stag beetles use this sensory information to adjust their fighting strategy as well. Finally, male jaws also need to resist the forceful bites inflicted by opponents. Even though this loading applies at other locations along the jaw, and bends the jaw in the opposite direction, our models show that the jaws are equally robust against these external forces as they are against the forces caused by their own biting.

  16. Efficacy of the Dynamic Jaw Mode in Helical Tomotherapy With Static Ports for Breast Cancer.

    PubMed

    Sugie, Chikao; Manabe, Yoshihiko; Hayashi, Akihiro; Murai, Taro; Takaoka, Taiki; Hattori, Yukiko; Iwata, Hiromitsu; Takenaka, Ran; Shibamoto, Yuta

    2015-08-01

    The recently developed dynamic jaw technology of tomotherapy can reduce craniocaudal dose spread without much prolonging the treatment time. This study aimed to investigate the efficacy of the dynamic jaw mode for tomotherapy of breast cancer. Static tomotherapy plans of the whole breast and supraclavicular regional lymph nodes, and plans for the whole breast only were generated in 25 patients with left-sided breast cancer. Plans with a field width of 2.5 or 5 cm with the dynamic or fixed jaw modes were made for each patient. The prescribed dose was 50 Gy in 25 fractions. In whole breast and supraclavicular nodal radiotherapy, dose distributions and homogeneity of the planning target volume (PTV) with the dynamic jaw mode were slightly inferior to those with the fixed jaw mode with a 5-cm field width (P < .05). However, lung low-dose volumes and mean doses of the larynx, thyroid, skin, and all the healthy tissues combined were smaller with the dynamic jaw mode than with the fixed jaw mode with a 5-cm field width (P < .001). In whole breast radiotherapy, mean doses of the skin and healthy tissues were lower with the dynamic jaw mode than with the fixed jaw mode with a 5-cm field width (P < .001) without significant differences in PTV dose distributions, homogeneity, and conformity. The dynamic jaw mode provided better sparing of organs at risks with minimal disturbance of dose-volume indices of PTV. Considering the treatment time, the 5-cm-field dynamic jaw mode is more efficient than the 2.5-cm fixed jaw mode.

  17. A monolateral TMJ replacement under intraoral endoscopic assistance for jaw osteomielitis: a modified approach

    PubMed Central

    BELLI, E.; MICI, E.; MAZZONE, N.; CATALFAMO, L.; FINI, G.; LIBERATORE, G.M.

    2015-01-01

    Alloplastic replacement has become a valid treatment for TMJ end-stage disease. The Alkayat and Bramley pre-auricular approach combined with the submandibular incision are the current surgical approaches for TMJ surgery. The present study shows a modified approach using intraoral endoscopic assistance. A female patient affected by jaw osteomielitis with condylar detachment was treated with total left TMJ alloplastic replacement combined with a right TMJ arthroplasty. No subamandibular incision was performed and, subsequently, the risks for permanent or temporary damage to the marginalis mandibulae nerve and surgical submandibular scar were avoided. Postoperative CT-Scan evidenced a good prosthesis position. No complications occurred after two years of follow-up. PMID:25827669

  18. Bisphosphonate-related osteonecrosis of the jaws: a single-center study of 101 patients.

    PubMed

    Lazarovici, Towy Sorel; Yahalom, Ran; Taicher, Shlomo; Elad, Sharon; Hardan, Izhar; Yarom, Noam

    2009-04-01

    Osteonecrosis of the jaw (ONJ) is a devastating side effect of long-term bisphosphonate (BP) use. We present the largest case series from a single department. This case series included 101 ONJ patients. Data on demographics, medical background, type and duration of BP use, possible triggering events, mode of therapy, and outcome were recorded. ONJ was associated with intravenous BPs in 85 patients and with oral BPs in 16 patients. It was diagnosed after 48, 27, and 67 months of pamidronate, zoledronic acid, and alendronate use, respectively. Long-term antibiotics and minimal surgical procedures resulted in complete or partial healing in 18% and 52% of the patients, respectively; 30% had no response. There was no association between ONJ and diabetes, steroid and antiangiogenic treatment, or underlying periodontal disease. Diagnostic biopsies aggravated lesions without being informative about pathogenesis. A conservative regimen is our treatment of choice. Solutions for decreasing morbidity and poor outcome of ONJ remain elusive.

  19. Bisphosphonates and oral pathology II. Osteonecrosis of the jaws: review of the literature before 2005.

    PubMed

    Estefanía Fresco, Ruth; Ponte Fernández, Ruth; Aguirre Urizar, José Manuel

    2006-11-01

    Bisphosphonates are bone-turnover modulating drugs which are used in the management of a number of bone diseases ranging from osteoporosis to neoplasic pathology-associated osteolysis. In the last years a number of cases of osteonecrosis of the jaws associated with these drugs have been reported. In this review we analyze the cases published in the literature indexed from 2003 to December 2005. During this period 246 cases were reported, being more frequently associated with women in the sixth decade of life. More frequently associated bisphosphonates were the nitrogenated bisphosphonates (pamidronate, zolendronic acid) and the most common oral antecedent was a dental extraction. Nevertheless more than 25% of the cases were spontaneous. The most frequent site was the mandible and most of the cases presented clinical evidence of bone exposure and pain. Different treatments have been proposed with different antibiotic therapies with or without surgery, showing in general terms an uncertain prognosis with low healing rates.

  20. [Histiocytosis X of the jaw. I. Anatomico-clinical study apropos of 61 cases].

    PubMed

    Chomette, G; Auriol, M; Ragot, J P; Guilbert, F

    1987-01-01

    61 cases of histiocytosis X of jaws were reported here. They occurred more often in man (72% of men) than in woman, with an average age of 27 years. The mandible was affected more frequently than the maxilla. Clinically, dental expulsion, gingival swelling, fractures or pain were the usual symptoms. Roentgenographic examination showed either central or peripheral (alveolar bone) osteolytic areas. The histologic diagnosis was easy when eosinophilic polymorphous leukocytes or histiocytes were preponderant. In the other cases, immunohistochemistry (positivity of S-100 protein) and electron microscopy (presence of Birbeck granules about paraffin embedded specimens) were of a great usefulness. The prognosis of the disease was mainly related to the diffusion of lesions to other skeletal portions or extraskeletal localizations (37% of our cases). It has been improved by combination of chemotherapy to surgery (despite of frequent recurrences), 40 upon 45 patients are well after a follow-up of 2 to 10 years after the last localization.

  1. Diagnosis and treatment of dynamic closed-mouth jaw locking in a dog.

    PubMed

    Frazho, Jean K; Tano, Cheryl A; Ferrell, Eric A

    2008-09-01

    A 5-year-old neutered male English Bulldog was evaluated for intermittent closed-mouth jaw locking of approximately 1 week's duration. Initial physical examination revealed a nonpainful inability to open the jaw with and without manual assistance; however, manipulation of the jaw after the dog was sedated for diagnostic imaging restored jaw function. Anesthesia was subsequently induced, and computed tomography was performed with the jaw open and closed; contrast agent-enhanced images of the closed jaw were also obtained. No abnormalities of the temporomandibular joints or retrobulbar space were detected. Fluoroscopic examination of movement of the temporomandibular joints revealed a dynamic interference of the rostrodorsal aspect of the coronoid process of the left mandibular ramus with the medial surface of the frontal process of the left zygomatic bone or the left orbital ligament. Partial excision of the coronoid process of the left mandibular ramus was performed. The dog recovered without complication and was able to open and close its jaw and eat within 6 hours after surgery. No additional episodes of jaw locking were detected during the 6 months after surgery. To the authors' knowledge, closed-mouth jaw locking in animals attributable to dynamic interference of the rostrodorsal aspect of the coronoid process of a mandibular ramus with the medial surface of the frontal process of a zygomatic bone or an orbital ligament has not been described. Surgical excision of the coronoid process of the mandibular ramus appeared to provide a successful outcome in the dog of this report.

  2. Mechanoreceptor distribution in stag beetle jaws corresponds to the material stress in fights.

    PubMed

    Goyens, J; Dirckx, J; Aerts, P

    2015-05-01

    Male stag beetles (Lucanidae) use their extremely elongated jaws to pinch their rivals forcefully in male-male battles. The morphology of these jaws has to be a compromise between robustness (to withstand the bite forces), length and weight. Cyclommatus metallifer stag beetles circumvent this trade-off by reducing their bite force when biting with their slender jaw tips. Here we describe the functional mechanism behind the force modulation behaviour. Scanning Electron Microscopy and micro CT imaging show large numbers of small sensors in the jaw cuticle. We find a strong correlation between the distribution of these sensors and that of the material stress in the same jaw region during biting. The jaw sensors are mechanoreceptors with a small protrusion that barely protrudes above the undulating jaw surface. The sensors stimulate dendrites that extend from the neuronal cell body through the entire thickness of the jaw exoskeleton towards the sensors at the external surface. They form a sensory field that functions in a feedback mechanism to control the bite muscle force. This negative feedback mechanism enabled the stag beetles to evolve massive bite muscles without risking overloading their valuable jaws.

  3. The retro-articular process, streptostyly and the caecilian jaw closing system.

    PubMed

    Summers, Adam P; Wake, Marvalee H

    2005-01-01

    Caecilians have two functionally separate sets of jaw closing muscles. The jaw adductor muscles are parallel fibered muscles positioned close to the jaw joint and their lever mechanics suggests they are well suited to rapidly closing the jaws. A second set of muscles, the hypaxial interhyoideus posterior (IHP), levers the jaws closed by pulling on the retro-articular process (RA) of the lower jaw. Models of the lower jaw point out that the angle and length of the RA has a profound effect on the closure force exerted by the IHP. The caecilian skull is streptostylic - the quadrate-squamosal apparatus (QSA) moves relative to the rest of the skull, a condition that seems at odds with a well-ossified cranium. Modeling the contribution of this streptostylic suspension of the lower jaw shows that rotational freedom of the QSA amplifies the force of the IHP by redirecting force applied along the low axis of the lower jaw. Measurements from several species and life stages of preserved caecilians reveal a large variation in predicted bite force (as a multiple of IHP force) with age and phylogeny.

  4. Micro-CT analysis of the rodent jaw bone micro-architecture: A systematic review.

    PubMed

    Faot, F; Chatterjee, M; de Camargos, G V; Duyck, Joke; Vandamme, K

    2015-06-01

    Knowledge about macro- and micro-structural characteristics may improve in vivo estimation of the quality and quantity of regenerated bone tissue. For this reason, micro-CT imaging has been applied to evaluate alveolar bone remodelling, alterations of periodontal ligament thickness and cortical and trabecular bone changes in rodent jaw bones. In this paper, we provide a systematic review on the available micro-CT literature on jaw bone micro-architecture. A detailed search through the PubMed database was performed. Articles published up to December 2013 and related to maxilla, mandible and condyle with quantitatively analysed bone micro-architectural parameters were considered eligible for inclusion. Two reviewers assessed the search results according to inclusion criteria designed to identify animal studies quantifying the bone micro-architecture of the jaw rodent bones in physiological or drug-induced disease status, or in response to interventions such as mechanical loading, hormonal treatment and other metabolic alterations. Finally, the reporting quality of the included publications was evaluated using the tailored ARRIVE guidelines outlined by Vignoletti and Abrahamsson (2012). Database search, additional manual searching and assessment of the inclusion and exclusion criteria retrieved 127 potentially relevant articles. Eventually, 14 maxilla, 20 mandible and 12 condyle articles with focus on bone healing were retained, and were analysed together with 3 methodological papers. Each study was described systematically in terms of subject, experimental intervention, follow-up period, selected region of interest used in the micro-CT analysis, parameters quantified, micro-CT scanner device and software. The evidence level evaluated by the ARRIVE guidelines showed high mean scores (between 18 and 25; range: 0-25), indicating that most of the selected studies are well-reported. The major obstacles identified were related to sample size calculation, absence of adverse

  5. The Covidien LigaSure Maryland Jaw Device.

    PubMed

    Zaidi, Nisar; Glover, Anthony R; Sidhu, Stanley B

    2015-03-01

    Since its invention nearly 20 years ago, the Covidien LigaSure device along with its ForceTriad generator has dominated the Electrothermal Bipolar Vessel Sealing market. The LigaSure was used for surgical procedures, both open and laparoscopic. The purpose of this review is to provide evidence of the safety and utility of the LigaSure device compared to more traditional means of hemostasis and its ultrasonic competitor, particularly in laparoscopic applications. We will provide evidence related to electrothermal bipolar vessel sealing in general and look specifically at Covidien's newest product, the LigaSure Maryland Jaw Device.

  6. Benign fibrous histiocytoma: A rare case involving jaw bone.

    PubMed

    Shoor, Hitesh; Pai, Keerthilatha M; Shergill, Ankur Kaur; Kamath, Abhay Taranath

    2015-09-01

    Benign fibrous histiocytoma (BFH) is a soft tissue neoplasm which occurs mostly on the skin of extremities. BFH rarely occurs in bone and may affect femur, tibia, and pelvic bone. Jaw bone involvement is very unusual with only 11 cases reported till date. This report describes a case of BFH occurring in a 30-year-old female patient affecting left mandibular posterior region. Computed tomography revealed a well-defined expansile lytic lesion in the posterior mandible. Gross examination of the tumor revealed an admixture of fibroblasts and histiocytes in a fascicular and storiform pattern. Immunohistochemical staining was positive for CD68.

  7. Benign fibrous histiocytoma: A rare case involving jaw bone

    PubMed Central

    Shoor, Hitesh; Pai, Keerthilatha M.; Shergill, Ankur Kaur; Kamath, Abhay Taranath

    2015-01-01

    Benign fibrous histiocytoma (BFH) is a soft tissue neoplasm which occurs mostly on the skin of extremities. BFH rarely occurs in bone and may affect femur, tibia, and pelvic bone. Jaw bone involvement is very unusual with only 11 cases reported till date. This report describes a case of BFH occurring in a 30-year-old female patient affecting left mandibular posterior region. Computed tomography revealed a well-defined expansile lytic lesion in the posterior mandible. Gross examination of the tumor revealed an admixture of fibroblasts and histiocytes in a fascicular and storiform pattern. Immunohistochemical staining was positive for CD68. PMID:26604585

  8. [Florid cemento-osseous dysplasia of the jaws].

    PubMed

    Benazzou, S; Boulaadas, M; El Ayoubi, A; Nazih, N; Essakalli, L; Kzadri, M

    2011-06-01

    Florid cemento-osseous dysplasia is a benign and rare tumor of the jaws. It is more commonly seen in middle-aged black women. Most cases are asymptomatic and are found during routine radiographic examination. We report two complicated cases of florid cemento-osseous dysplasia, one with facial deformity and the other with chronic osteitis. The diagnosis of florid cemento-osseous dysplasia is based on clinical and radiological features. The lesions are commonly bilateral and symmetrical. Copyright © 2011. Published by Elsevier Masson SAS.

  9. Osteonecrosis of the jaw in patient with denosumab therapy.

    PubMed

    Olate, Sergio; Uribe, Francisca; Martinez, Felipe; Almeida, Andrés; Unibazo, Alejandro

    2014-01-01

    Osteonecrosis (ON) of the jaw has previously been linked to the use of biphosphonates; however, new drugs, also shown similar conditions. This article presents a female patient with mandibular ON related to the use of denosumab. The 55-year-old presented with bone exposure with 8 months of evolution after a dental extraction. The patient began subcutaneous injections of 60 mg denosumab four months prior to the extraction and the lesion remained after the procedure. The patient, with 14 months of follow-up, show mandible ON with no favorable evolution. The clinical condition is presented and the literature of ON associated with denosumab is discussed.

  10. 3D-model building of the jaw impression

    NASA Astrophysics Data System (ADS)

    Ahmed, Moumen T.; Yamany, Sameh M.; Hemayed, Elsayed E.; Farag, Aly A.

    1997-03-01

    A novel approach is proposed to obtain a record of the patient's occlusion using computer vision. Data acquisition is obtained using intra-oral video cameras. The technique utilizes shape from shading to extract 3D information from 2D views of the jaw, and a novel technique for 3D data registration using genetic algorithms. The resulting 3D model can be used for diagnosis, treatment planning, and implant purposes. The overall purpose of this research is to develop a model-based vision system for orthodontics to replace traditional approaches. This system will be flexible, accurate, and will reduce the cost of orthodontic treatments.

  11. Osteonecrosis of the jaw in patient with denosumab therapy

    PubMed Central

    Olate, Sergio; Uribe, Francisca; Martinez, Felipe; Almeida, Andrés; Unibazo, Alejandro

    2014-01-01

    Osteonecrosis (ON) of the jaw has previously been linked to the use of biphosphonates; however, new drugs, also shown similar conditions. This article presents a female patient with mandibular ON related to the use of denosumab. The 55-year-old presented with bone exposure with 8 months of evolution after a dental extraction. The patient began subcutaneous injections of 60 mg denosumab four months prior to the extraction and the lesion remained after the procedure. The patient, with 14 months of follow-up, show mandible ON with no favorable evolution. The clinical condition is presented and the literature of ON associated with denosumab is discussed. PMID:25419421

  12. Age Changes of Jaws and Soft Tissue Profile

    PubMed Central

    Sharma, Padmaja; Arora, Ankit; Valiathan, Ashima

    2014-01-01

    Age-related changes of jaws and soft tissue profile are important both for orthodontists and general dentists. Mouth profile is the area which is manipulated during dental treatment. These changes should be planned in accordance with other components of facial profile to achieve ultimate aim of structural balance, functional efficacy, and esthetic harmony. Through this paper, the authors wish to discuss age changes of the hard and soft tissues of human face which would help not only the orthodontists but also oral surgeons, prosthodontists, pedodontists, and general dentists. PMID:25506064

  13. Postoperative myocardial infarction in an orthognatic jaw surgery.

    PubMed

    Vieira Marques, F; Montenegro Sá, F; Lapa, T; Simões, I

    2017-07-29

    Cardiovascular complications, in particular perioperative myocardial infarctions, are central contributors to morbidity and mortality after non-cardiac surgery. We present a case of a 41-year-old male, smoker and dyslipidemic, who underwent bimaxillary orthognathic jaw surgery with the development of an acute coronary syndrome in the immediate postoperative period. We managed to early diagnose the myocardial infarction and promptly performed a percutaneous transluminal coronary angioplasty, resulting in a positive outcome. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Multiple fibromyxomas of the jaws: A case report

    PubMed Central

    Eiid, Salma Belal

    2014-01-01

    Fibromyxoma of the jaw is a rare benign mesenchymal odontogenic tumor with locally aggressive behavior. In the present report, a 13-year-old female patient presented to our university hospital with delayed eruption of some of her teeth. A panoramic radiograph taken at the initial examination revealed four pericoronal radiolucencies related to the four third molars. Thereafter, a magnetic resonance imaging (MRI) examination was performed. After the surgical removal of these molars, the microscopic examination diagnosed the four lesions as fibromyxomas. Here, we have discussed the clinical, panoramic radiography, MRI, and histopathological findings of the case. PMID:25279345

  15. [Juvenile ossifying fibroma: a misgiving tumor of the jaws].

    PubMed

    Odin, Guillaume; Benchetrit, Maxime; Raybaud, Hélène; Balaguer, Thierry; Soler, Christine; Michiels, Jean-François

    2012-02-01

    Juvenile ossifying fibroma is a rare benign tumour of childhood. It is hardly distinguishable from others fibro-osseous lesions because of their overlapping microscopic features. Juvenile variant of ossifying fibroma may be mistaken for malignancy, particularly osteosarcoma. Radiology is central to their diagnosis because of the very limited nature of the tumour. Microscopically, the lack of cytologic atypia or abnormal mitosis, and the presence of bone maturation or cementum deposits are consistent with an ossifying fibroma. This entity should be kept in mind regarding any bone lesion jaws in children. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  16. Antiresorptive drug-related osteonecrosis of the jaw.

    PubMed

    Uyanne, Jettie; Calhoun, Colonya C; Le, Anh D

    2014-04-01

    Nitrogen-containing and non-nitrogen-containing bisphosphonates have been implicated in the development of osteonecrosis of the jaw (ONJ), a condition termed bisphosphonate-related OHJ. Other antiresorptive drugs have been implicated in the development of OHJ, hence the new term antiresorptive drug-related ONJ. The underlying pathogenesis remains unclear, and no definite diagnosis or cure has been established for this debilitating condition. This article reviews some of the most common antiresorptive drugs with their associated risks of ONJ and the current understanding of the pathogenesis ONJ, and summarizes current clinical guidelines.

  17. Pharmacogenetics of Bisphosphonate-associated Osteonecrosis of the Jaw.

    PubMed

    Fung, P L; Nicoletti, P; Shen, Y; Porter, S; Fedele, S

    2015-11-01

    Osteonecrosis of the jaws (ONJ) is a potentially severe disorder that develops in a subgroup of individuals who have used bisphosphonate (BP) medications. Several clinical risk factors have been associated with the risk of ONJ development, but evidence is limited and in most instances ONJ remains an unpredictable adverse drug reaction. Interindividual genetic variability can contribute to explaining ONJ development in a subset of BP users and the discovery of relevant associated gene variants could lead to the identification of individuals at higher risk. No genetic variant has been found to be robustly associated with susceptibility to ONJ. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Kinematic linkage of the tongue, jaw, and hyoid during eating and speech

    PubMed Central

    Matsuo, Koichiro; Palmer, Jeffrey B.

    2010-01-01

    Objective Tongue movement is temporo-spatially coordinated with jaw and hyoid movements during eating and speech. As such, we evaluated 1) the correlation between the tongue with jaw and hyoid movements during eating and speech and 2) the relative influence of the jaw and hyoid on determining tongue movement. Design Lateral projection videofluorography was recorded while 16 healthy subjects ate solid foods or read a standard passage. The position of anterior and posterior tongue markers (ATM and PTM, respectively), the jaw, and the hyoid relative to the upper occlusal plane was quantified with the upper canine as the origin (0,0) point for Cartesian coordinates. For vertical and horizontal dimensions, separate multiple linear regression analyses were performed with ATM or PTM position as a function of jaw and hyoid positions. Results Vertically, both ATM and PTM positions were highly correlated with the jaw and hyoid during eating (median r = 0.87). The relative influence was higher for the jaw than the hyoid for ATM position (P < 0.001), but lower for PTM position (P = 0.04). Horizontally, tongue marker positions had moderate correlation with the jaw and hyoid during eating (r = 0.47), due more to hyoid position than to jaw position. Overall, correlations were lower during speech than eating. Conclusion This study demonstrated distinct kinematic linkages between the movements of the jaw, the hyoid and the anterior and posterior tongue markers, as well as differing impact of the jaw and the hyoid in determining tongue movement during eating and speech. PMID:20236625

  19. SU-F-E-19: A Novel Method for TrueBeam Jaw Calibration

    SciTech Connect

    Corns, R; Zhao, Y; Huang, V

    2016-06-15

    Purpose: A simple jaw calibration method is proposed for Varian TrueBeam using an EPID-Encoder combination that gives accurate fields sizes and a homogeneous junction dose. This benefits clinical applications such as mono-isocentric half-beam block breast cancer or head and neck cancer treatment with junction/field matching. Methods: We use EPID imager with pixel size 0.392 mm × 0.392 mm to determine the radiation jaw position as measured from radio-opaque markers aligned with the crosshair. We acquire two images with different symmetric field sizes and record each individual jaw encoder values. A linear relationship between each jaw’s position and its encoder value is established, from which we predict the encoder values that produce the jaw positions required by TrueBeam’s calibration procedure. During TrueBeam’s jaw calibration procedure, we move the jaw with the pendant to set the jaw into position using the predicted encoder value. The overall accuracy is under 0.1 mm. Results: Our in-house software analyses images and provides sub-pixel accuracy to determine field centre and radiation edges (50% dose of the profile). We verified the TrueBeam encoder provides a reliable linear relationship for each individual jaw position (R{sup 2}>0.9999) from which the encoder values necessary to set jaw calibration points (1 cm and 19 cm) are predicted. Junction matching dose inhomogeneities were improved from >±20% to <±6% using this new calibration protocol. However, one technical challenge exists for junction matching, if the collimator walkout is large. Conclusion: Our new TrueBeam jaw calibration method can systematically calibrate the jaws to crosshair within sub-pixel accuracy and provides both good junction doses and field sizes. This method does not compensate for a larger collimator walkout, but can be used as the underlying foundation for addressing the walkout issue.

  20. An examination of the degrees of freedom of human jaw motion in speech and mastication.

    PubMed

    Ostry, D J; Vatikiotis-Bateson, E; Gribble, P L

    1997-12-01

    The kinematics of human jaw movements were assessed in terms of the three orientation angles and three positions that characterize the motion of the jaw as a rigid body. The analysis focused on the identification of the jaw's independent movement dimensions, and was based on an examination of jaw motion paths that were plotted in various combinations of linear and angular coordinate frames. Overall, both behaviors were characterized by independent motion in four degrees of freedom. In general, when jaw movements were plotted to show orientation in the sagittal plane as a function of horizontal position, relatively straight paths were observed. In speech, the slopes and intercepts of these paths varied depending on the phonetic material. The vertical position of the jaw was observed to shift up or down so as to displace the overall form of the sagittal plane motion path of the jaw. Yaw movements were small but independent of pitch, and vertical and horizontal position. In mastication, the slope and intercept of the relationship between pitch and horizontal position were affected by the type of food and its size. However, the range of variation was less than that observed in speech. When vertical jaw position was plotted as a function of horizontal position, the basic form of the path of the jaw was maintained but could be shifted vertically. In general, larger bolus diameters were associated with lower jaw positions throughout the movement. The timing of pitch and yaw motion differed. The most common pattern involved changes in pitch angle during jaw opening followed by a phase predominated by lateral motion (yaw). Thus, in both behaviors there was evidence of independent motion in pitch, yaw, horizontal position, and vertical position. This is consistent with the idea that motions in these degrees of freedom are independently controlled.

  1. A biomechanical model for analysis of muscle force, power output and lower jaw motion in fishes.

    PubMed

    Westneat, Mark W

    2003-08-07

    Fish skulls are complex kinetic systems with movable components that are powered by muscles. Cranial muscles for jaw closing pull the mandible around a point of rotation at the jaw joint using a third-order lever mechanism. The present study develops a lever model for the jaw of fishes that uses muscle design and the Hill equation for nonlinear length-tension properties of muscle to calculate dynamic power output. The model uses morphometric data on skeletal dimensions and muscle proportions in order to predict behavior and force transmission mediated by lever action. The computer model calculates a range of dynamic parameters of jaw function including muscle force, torque, effective mechanical advantage, jaw velocity, bite duration, bite force, work and power. A complete list of required morphometrics is presented and a software program (MandibLever 2.0) is available for implementing lever analysis. Results show that simulations yield kinematics and timing profiles similar to actual fish feeding events. Simulation of muscle properties shows that mandibles reach their peak velocity near the start of jaw closing, peak force at the end of jaw closing, and peak power output at about 25% of the closing cycle time. Adductor jaw muscles with different mechanical designs must have different contractile properties and/or different muscle activity patterns to coordinate jaw closing. The effective mechanical advantage calculated by the model is considerably lower than the mechanical advantage estimated from morphological lever ratios, suggesting that previous studies of morphological lever ratios have overestimated force and underestimated velocity transmission to the mandible. A biomechanical model of jaw closing can be used to interpret the mechanics of a wide range of jaw mechanisms and will enable studies of the functional results of developmental and evolutionary changes in skull morphology and physiology.

  2. A preliminary analysis of the relationship between jaw-muscle architecture and jaw-muscle electromyography during chewing across primates.

    PubMed

    Vinyard, Christopher J; Taylor, Andrea B

    2010-04-01

    The architectural arrangement of the fibers within a muscle has a significant impact on how a muscle functions. Recent work on primate jaw-muscle architecture demonstrates significant associations with dietary variation and feeding behaviors. In this study, the relationship between masseter and temporalis muscle architecture and jaw-muscle activity patterns is explored using Belanger's treeshrews and 11 primate species, including two genera of strepsirrhines (Lemur and Otolemur) and five genera of anthropoids (Aotus, Callithrix, Cebus, Macaca, and Papio). Jaw-muscle weights, fiber lengths, and physiologic cross-sectional areas (PCSA) were quantified for this preliminary analysis or collected from the literature and compared to published electromyographic recordings from these muscles. Results indicate that masseter architecture is unrelated to the superficial masseter working-side/balancing-side (W/B) ratio across primate species. Alternatively, relative temporalis architecture is correlated with temporalis W/B ratios across primates. Specifically, relative temporalis PCSA is inversely related to the W/B ratio for the anterior temporalis, indicating that as animals recruit a larger relative percentage of their balancing-side temporalis, they possess the ability to generate relatively larger amounts of force from these muscles. These findings support three broader conclusions. First, masseter muscle architecture may have experienced divergent evolution across different primate clades related to novel functional roles in different groups. Second, the temporalis may be functionally constrained (relative to the masseter) across primates in its functional role of creating vertical occlusal forces during chewing. Finally, the contrasting results for the masseter and temporalis suggest that the fiber architecture of these muscles has evolved as distinct functional units in primates.

  3. A Preliminary Analysis of the Relationship between Jaw-Muscle Architecture and Jaw-Muscle Electromyography during Chewing Across Primates

    PubMed Central

    Vinyard, Christopher J.; Taylor, Andrea B.

    2011-01-01

    The architectural arrangement of the fibers within a muscle has a significant impact on how a muscle functions. Recent work on primate jaw-muscle architecture demonstrates significant associations with dietary variation and feeding behaviors. In this study, the relationship between masseter and temporalis muscle architecture and jaw-muscle activity patterns is explored using Belanger's treeshrews and 11 primate species, including three genera of strepsirrhines (Lemur, Otolemur) and five genera of anthropoids (Aotus, Callithrix, Cebus, Macaca, Papio). Jaw-muscle weights, fiber lengths and physiologic cross-sectional areas (PCSA) were quantified for this preliminary analysis or collected from the literature and compared to published electromyographic (EMG) recordings from these muscles. Results indicate that masseter architecture is unrelated to the superficial masseter working-side/balancing-side (W/B) ratio across primate species. Alternatively, relative temporalis architecture is correlated with temporalis W/B ratios across primates. Specifically, relative temporalis PCSA is inversely related to the W/B ratio for the anterior temporalis indicating that as animals recruit a larger relative percentage of their balancing-side temporalis, they possess the ability to generate relatively larger amounts of force from these muscles. These findings support three broader conclusions. First, masseter muscle architecture may have experienced divergent evolution across different primate clades related to novel functional roles in different groups. Second, the temporalis may be functionally constrained (relative to the masseter) across primates in its functional role of creating vertical occlusal forces during chewing. Finally, the contrasting results for the masseter and temporalis suggest that the fiber architecture of these muscles has evolved as distinct functional units in primates. PMID:20235313

  4. Bisphosphonate-related osteonecrosis of the jaw: awareness and level of knowledge of Lebanese physicians.

    PubMed

    El Osta, Lana; El Osta, Badi; Lakiss, Sara; Hennequin, Martine; El Osta, Nada

    2015-09-01

    Bisphosphonate-induced osteonecrosis of the jaw (ONJ) is a potentially destructive complication, particularly encountered in oncology. It is supposed that awareness and good knowledge of this disease by physicians are important factors of its early detection and management. This study aims to evaluate the level of knowledge among a sample of Lebanese physicians with regard to this complication. An observational cross-sectional study was conducted at Hôtel-Dieu de France hospital between March and June 2013. Data were collected through a self-administered questionnaire distributed to 190 eligible physicians in the departments involved in prescribing bisphosphonates and managing the ONJ. A total of 136 valid responses were obtained (response rate 71.6 %). Eighty-six (63.2 %) physicians were treating patients with bisphosphonates: the most prescribed form being the weekly oral bisphosphonates for osteoporosis followed by zoledronate several times yearly for bone malignancies. Fifty-one (37.5 %) participants were unaware of bisphosphonate-related ONJ. Furthermore, the level of knowledge was relatively poor: the mean score of all participants was 12.42 ± 10.08, while 77 (56.6 %) had a global score more than 16 over 30. There were statistically significant associations between the level of knowledge and physicians' specialty (p value <0.0001), whether or not they prescribe bisphosphonates (p value = 0.039), the most frequently form prescribed (p value = 0.048), whether or not they attend patients already on bisphosphonate (p value = 0.047), whether or not they have observed (p value = 0.004) and treated (p value = 0.002) exposed necrotic bone of the jaw. Our study revealed a deficient knowledge regarding bisphosphonate-related ONJ among Lebanese physicians. Appropriate training strategies to increase their awareness are required.

  5. Prevalence of osteonecrosis of the jaw in patients with oral bisphosphonate exposure.

    PubMed

    Lo, Joan C; O'Ryan, Felice S; Gordon, Nancy P; Yang, Jingrong; Hui, Rita L; Martin, Daniel; Hutchinson, Matthew; Lathon, Phenius V; Sanchez, Gabriela; Silver, Paula; Chandra, Malini; McCloskey, Carolyn A; Staffa, Judy A; Willy, Mary; Selby, Joe V; Go, Alan S

    2010-02-01

    Osteonecrosis of the jaw (ONJ) is a serious complication associated with bisphosphonate therapy, but its epidemiology in the setting of oral bisphosphonate therapy is poorly understood. The present study examined the prevalence of ONJ in patients receiving chronic oral bisphosphonate therapy. We mailed a survey to 13,946 members who had received chronic oral bisphosphonate therapy as of 2006 within a large integrated health care delivery system in Northern California. Respondents who reported ONJ, exposed bone or gingival sores, moderate periodontal disease, persistent symptoms, or complications after dental procedures were invited for examination or to have their dental records reviewed. ONJ was defined as exposed bone (of >8 weeks' duration) in the maxillofacial region in the absence of previous radiotherapy. Of the 8,572 survey respondents (71 +/- 9 years, 93% women), 2,159 (25%) reported pertinent dental symptoms. Of these 2,159 patients, 1,005 were examined and an additional 536 provided dental records. Nine ONJ cases were identified, representing a prevalence of 0.10% (95% confidence interval 0.05% to 0.20%) among the survey respondents. Of the 9 cases, 5 had occurred spontaneously (3 in palatal tori) and 4 occurred in previous extraction sites. An additional 3 patients had mandibular osteomyelitis (2 after extraction and 1 with implant failure) but without exposed bone. Finally, 7 other patients had bone exposure that did not fulfill the criteria for ONJ. ONJ occurred in 1 of 952 survey respondents with oral bisphosphonate exposure (minimum prevalence of 1 in 1,537 of the entire mailed cohort). A similar number had select features concerning for ONJ that did not meet the criteria. The results of the present study provide important data on the spectrum of jaw complications among patients with oral bisphosphonate exposure. Copyright 2010 American Association of Oral and Maxillofacial Surgeons. All rights reserved.

  6. The national-scale cohort study on bisphosphonate-related osteonecrosis of the jaw in Taiwan.

    PubMed

    Yuh, Da-Yo; Chang, Ting-Han; Huang, Ren-Yeong; Chien, Wu-Chien; Lin, Fu-Gong; Fu, Earl

    2014-10-01

    Osteonecrosis of the jaw (ONJ) is a potential side effect of bisphosphonate therapy. This Taiwanese national-scale cohort study aimed to investigate its incidence and risk of development by using a qualified control group with different demographic factors (age/gender), dental (tooth extraction/periodontal therapy) and medical (jaw radiotherapy) treatments, delivery routes (oral/intravenous), and diseases (diabetes/osteoporosis/cancer). Data (n=958,136) from January 1, 2006 through December 31, 2008 were sourced from the Longitudinal Health Insurance Database 2005 of Taiwan. Cases of BRONJ were identified by three criteria modified from the definition proposed by the American Association of Oral and Maxillofacial Surgeons. The Cox proportional-hazards regression model and Kaplan-Meier estimates were used to analyse the results. The incidence densities of ONJ in the unexposed and bisphosphonate-exposed cohorts were estimated as 4.4 and 73.5 per 100,000 person-years, respectively (relative risk=16.8; 95% CI=6.0-37.5; P<0.001). Multivariate analysis revealed strong associations of delivery route, tooth extraction, and oral cancer with ONJ (hazard ratios=51.4 for oral bisphosphonates, 153.3 for intravenous bisphosphonates, 5.3 for tooth extraction, and 278.1 for oral cancer). These results not only demonstrate the incidence and relative risk of bisphosphonate-related ONJ in Taiwan but also indicate that tooth extraction and oral cancer may have a major impact on its development. Physicians should be aware of individual patient risk factors before prescribing bisphosphonates. Bisphosphonate treatment is justified in the amelioration of life-threatening conditions in patients in whom ONJ would only affect quality of life. Copyright © 2014. Published by Elsevier Ltd.

  7. Relationship between jaw opening force and hyoid bone dynamics in healthy elderly subjects

    PubMed Central

    Shinozaki, Hiromichi; Tohara, Haruka; Matsubara, Mariko; Inokuchi, Nobuhiro; Yamazaki, Yasuhiro; Nakane, Ayako; Wakasugi, Yoko; Minakuchi, Shunsuke

    2017-01-01

    Purpose This study aimed to examine the relationship between jaw opening force and hyoid bone dynamics and resting position in elderly individuals based on gender. Subjects and methods Subjects were 36 healthy elderly individuals aged ≥65 years without dysphagia (16 men and 20 women; mean age 75.5 years, range 65–88 years). Videofluorographic images during the swallowing of 10 mL of 40% (w/v) barium sulfate were obtained and the degrees of anterior, superior, and hypotenuse displacements of the hyoid bone and maximum/resting hyoid position were evaluated. Jaw opening force was measured three times using a jaw opening force sthenometer; the mean of these three measurements was used for analysis. Results In men, there was a positive correlation between jaw opening force and resting hyoid position and negative correlations among all the degrees of anterior, superior, and hypotenuse displacements of the hyoid bone. In women, there was no statistically significant correlation between jaw opening force and any of the measurement items. There was no statistically significant correlation between jaw opening force and maximum hyoid position in either men or women. Conclusion Our findings suggest that low jaw opening force leads to low resting hyoid position only in elderly men, and a lower hyoid position in healthy elderly men results in a larger total amount of hyoid displacement during swallowing. Moreover, a maximum hyoid position in healthy individuals of either gender does not differ depending on their jaw opening force. PMID:28408812

  8. Exploring gradients of halogens and zinc in the surface and subsurface of Nereis jaws.

    PubMed

    Khan, Rashda K; Stoimenov, Peter K; Mates, Thomas E; Waite, J Herbert; Stucky, Galen D

    2006-09-26

    The outstanding mechanical properties of impact-bearing tissues, such as Nereis jaws, make their morphology and chemical composition a subject of particular interest. The complex structure of the jaw was recently reported to exhibit molecular gradients that were closely correlated with stiffness and hardness.(18) Accordingly, we have explored the spatial distribution and bonding chemistries of Zn and the halogens in the surface structure of the jaws. Using secondary ion mass spectrometry (SIMS) and scanning electron microscopy (SEM), we found that Cl, Br, and I distributions are enhanced in surface layers of the basal protected portion of the jaw but are shifted to greater depths toward the exposed jaw tip. There are thus two complementary halogen gradients in the jaw: one on the surface that decreases from the base to the tip, coupled to an increasing one in the subsurface layers. The outer surface coating appeared to have granular morphology, in contrast to the anisotropic, fibrous core that dominates the subarchitecture. Using X-ray photoelectron spectroscopy (XPS), we discovered that Zn, I, and Br in the jaws have single chemical environments whereas chlorine is present in two distinct modes (Cl-Zn and Cl-C). Given the inverse relationship between surface exposure and halogen abundance in the jaws, it is unlikely that the halogens contribute directly to mechanical properties such as wear and hardness.

  9. Physiologic Development of Tongue-Jaw Coordination from Childhood to Adulthood

    ERIC Educational Resources Information Center

    Cheng, Hei Yan; Murdoch, Bruce E.; Goozee, Justine V.; Scott, Dion

    2007-01-01

    Purpose: This investigation aimed to examine the development of tongue-jaw coordination during speech from childhood to adolescence. Method: Electromagnetic articulography was used to track tongue and jaw motion in 48 children and adults (aged 6-38 years) during productions of /t/ and /k/ embedded in sentences. Results: The coordinative…

  10. Electronic speckle-pattern interferometry (ESPI) applied to the study of mechanical behavior of human jaws

    NASA Astrophysics Data System (ADS)

    Roman, Juan F.; Moreno de las Cuevas, Vincente; Salgueiro, Jose R.; Suarez, David; Fernandez, Paula; Gallas, Mercedes; Blanchard, Alain

    1996-01-01

    The study of the mechanical behavior of the human jaw during chewing is helpful in several specific medical fields that cover the maxillo-facial area. In this work, electronic speckle pattern interferometry has been applied to study dead jaw bones under external stress which simulates the deformations induced during chewing. Fringes obtained after subtraction of two images of the jaw, the image of the relaxed jaw and that of the jaw under stress, give us information about the most stressed zones. The interferometric analysis proposed here is attractive as it can be done in real time with the jaw under progressive stress. Image processing can be applied for improving the quality of fringes. This research can be of help in orthognathic surgery, for example in diagnosis and treatment of fractured jaws, in oral surgery, and in orthodontics because it would help us to know the stress dispersion when we insert an osseointegrated implant or place an orthodontic appliance, respectively. Studying fragments of human jaw some results about its elasticity and flexibility were obtained.

  11. Epidemiology of the sarcomas of the jaws in a Peruvian population

    PubMed Central

    Sacsaquispe-Contreras, Sonia J.; Morales-Vadillo, Rafael; Sánchez Lihón, Juvenal

    2012-01-01

    Objective: Analysis of the clinical characteristics of patients with Sarcomas of the Jaws treated in the “Instituto Nacional de Enfermedades Neoplasicas. Dr. Eduardo Caceres Graziani” from 1952-2007. Study Design: Review of 155 clinical records of patients with Sarcomas of the Jaws and record of age, gender, size, location, clinical symptoms and signs, histopathological diagnoses and type of treatment. The data obtained were analyzed by means of Student’s statistical t-test, Fisher and Friedman’s test. Results: Analysis of 155 Sarcomas of the Jaws. The average age of patients was 36.8 years old (range: 1-80 years); the female gender was the most frequent (52.9%); the average tumor size was 5.5 cm; in upper jaw 54.84% occurred and 45.16% in the lower jaw; the predominant sign was facial asymmetry (87.74%) and the predominant symptom: pain (63.23%). The most frequent diagnosis was Osteosarcoma 50.3% followed by Chondrosarcoma 18%. Surgery plus radiation therapy was the treatment type of choice with 21.94% of cases. Conclusion: The results of this study demonstrate the delayed diagnosis and facial asymmetry and pain appear as the most important events for the diagnosis of Sarcomas of the Jaws. Key words: Sarcoma, jaw, jaw neoplasms, mouth neoplasms. PMID:22143684

  12. The Speech Focus Position Effect on Jaw-Finger Coordination in a Pointing Task

    ERIC Educational Resources Information Center

    Rochet-Capellan, Amelie; Laboissiere, Rafael; Galvan, Arturo; Schwartz, Jean-Luc

    2008-01-01

    Purpose: This article investigates jaw-finger coordination in a task involving pointing to a target while naming it with a 'CVCV (e.g., /'papa/) versus CV'CV (e.g., /pa'pa/) word. According to the authors' working hypothesis, the pointing apex (gesture extremum) would be synchronized with the apex of the jaw-opening gesture corresponding to the…

  13. [Changes in the jaw-opening reflex during anesthesia resulting from auricular electrostimulation].

    PubMed

    Dolgikh, V G; Reshetniak, V K

    1987-05-01

    The effect of auricular electrostimulation on the jaw opening reflex and affective behaviour of adult cats was studied in chronic experiments during stimulation of the lip. Auricular electrostimulation was shown to facilitate the jaw opening reflex and to inhibit the affective component of the pain.

  14. The Effect of Jaw Position on Measures of Tongue Strength and Endurance

    ERIC Educational Resources Information Center

    Solomon, Nancy Pearl; Munson, Benjamin

    2004-01-01

    Assessment of tongue strength and endurance is common in research and clinical contexts. It is unclear whether the results reveal discrete function by the tongue or combined abilities of the tongue and jaw. One way to isolate the movement of the tongue is to constrain the jaw kinematically by using a bite block. In this study, 10 neurologically…

  15. The Effect of Jaw Position on Measures of Tongue Strength and Endurance

    ERIC Educational Resources Information Center

    Solomon, Nancy Pearl; Munson, Benjamin

    2004-01-01

    Assessment of tongue strength and endurance is common in research and clinical contexts. It is unclear whether the results reveal discrete function by the tongue or combined abilities of the tongue and jaw. One way to isolate the movement of the tongue is to constrain the jaw kinematically by using a bite block. In this study, 10 neurologically…

  16. Physiologic Development of Tongue-Jaw Coordination from Childhood to Adulthood

    ERIC Educational Resources Information Center

    Cheng, Hei Yan; Murdoch, Bruce E.; Goozee, Justine V.; Scott, Dion

    2007-01-01

    Purpose: This investigation aimed to examine the development of tongue-jaw coordination during speech from childhood to adolescence. Method: Electromagnetic articulography was used to track tongue and jaw motion in 48 children and adults (aged 6-38 years) during productions of /t/ and /k/ embedded in sentences. Results: The coordinative…

  17. The Speech Focus Position Effect on Jaw-Finger Coordination in a Pointing Task

    ERIC Educational Resources Information Center

    Rochet-Capellan, Amelie; Laboissiere, Rafael; Galvan, Arturo; Schwartz, Jean-Luc

    2008-01-01

    Purpose: This article investigates jaw-finger coordination in a task involving pointing to a target while naming it with a 'CVCV (e.g., /'papa/) versus CV'CV (e.g., /pa'pa/) word. According to the authors' working hypothesis, the pointing apex (gesture extremum) would be synchronized with the apex of the jaw-opening gesture corresponding to the…

  18. Raman Spectroscopic Analyses of Jaw Periosteal Cell Mineralization

    PubMed Central

    Brauchle, Eva; Carvajal Berrio, Daniel; Rieger, Melanie; Schenke-Layland, Katja; Reinert, Siegmar

    2017-01-01

    To achieve safer patient treatments, serum-free cell culture conditions have to be established for cell therapies. In previous studies, we demonstrated that serum-free culture favored the proliferation of MSCA-1+ osteoprogenitors derived from the jaw periosteum. In this study, the in vitro formation of bone-specific matrix by MSCA-1+ jaw periosteal cells (JPCs, 3 donors) was assessed and compared under serum-free and serum-containing media conditions using the marker-free Raman spectroscopy. Based on a standard fluorescence assay, JPCs from one patient were not able to mineralize under serum-containing culture conditions, whereas the other cells showed similar mineralization levels under both conditions. Raman spectra from mineralizing MSCA-1+ JPCs revealed higher levels of hydroxyapatite formation and higher mineral to matrix ratios under serum-free culture conditions. Higher carbonate to phosphate ratios and higher crystallinity in JPCs cultured under serum-containing conditions indicated immature bone formation. Due to reduced collagen production under serum-free conditions, we obtained significant differences in collagen maturity and proline to hydroxyproline ratios compared to serum-free conditions. We conclude that Raman spectroscopy is a useful tool for the assessment and noninvasive monitoring of in vitro mineralization of osteoprogenitor cells. Further studies should extend this knowledge and improve JPC mineralization by optimizing culture conditions. PMID:28232849

  19. Osteonecrosis of the jaws in patients treated with bisphosphonates

    PubMed Central

    Ata-Ali, Fadi; Flichy-Fernández, Antonio J.; Bagan, José V.

    2012-01-01

    The literature describes an increasing presence of bisphosphonate-induced osteonecrosis of the jaws (ONJ), characterized by the exposure for over 8 weeks of necrotic bone in the maxillofacial region, after bisphosphonate therapy, in the absence of prior maxillary radiotherapy. The present literature review examines the etiopathogenesis, risk factors, clinical forms, diagnosis, treatment and prevention of bisphosphonate-induced ONJ. In addition, a review is made of all the series involving over 15 patients diagnosed with this disorder between 1 January 2011 and 15 May 2011. A PubMed-Medline search was carried out with the following key words: “bisphosphonates” and “osteonecrosis”. The appearance of osteonecrosis is a serious complication, with an increasing incidence, that affects patient quality of life and causes important morbidity. All patients treated with bisphosphonates are at risk of developing osteonecrosis as a result of such medication. This potential complication therefore should be explained to the patient by both the prescribing physician and the dental surgeon in charge of oral treatment, with the obtainment of informed consent in all cases. Key words:Osteonecrosis of the jaws, bisphosphonates, etiopathogenesis, prevention, treatment. PMID:24558527

  20. Convergent evolution of hemoglobin switching in jawed and jawless vertebrates.

    PubMed

    Rohlfing, Kim; Stuhlmann, Friederike; Docker, Margaret F; Burmester, Thorsten

    2016-02-01

    During development, humans and other jawed vertebrates (Gnathostomata) express distinct hemoglobin genes, resulting in different hemoglobin tetramers. Embryonic and fetal hemoglobin have higher oxygen affinities than the adult hemoglobin, sustaining the oxygen demand of the developing organism. Little is known about the expression of hemoglobins during development of jawless vertebrates (Agnatha). We identified three hemoglobin switches in the life cycle of the sea lamprey. Three hemoglobin genes are specifically expressed in the embryo, four genes in the filter feeding larva (ammocoete), and nine genes correspond to the adult hemoglobin chains. During the development from the parasitic to the reproductive adult, the composition of hemoglobin changes again, with a massive increase of chain aHb1. A single hemoglobin chain is expressed constitutively in all stages. We further showed the differential expression of other globin genes: Myoglobin 1 is most highly expressed in the reproductive adult, myoglobin 2 expression peaks in the larva. Globin X1 is restricted to the embryo; globin X2 was only found in the reproductive adult. Cytoglobin is expressed at low levels throughout the life cycle. Because the hemoglobins of jawed and jawless vertebrates evolved independently from a common globin ancestor, hemoglobin switching must also have evolved convergently in these taxa. Notably, the ontogeny of sea lamprey hemoglobins essentially recapitulates their phylogeny, with the embryonic hemoglobins emerging first, followed by the evolution of larval and adult hemoglobins.

  1. ECM remodelling components regulated during jaw periosteal cell osteogenesis.

    PubMed

    Alexander, Dorothea; Ardjomandi, Nina; Munz, Adelheid; Friedrich, Björn; Reinert, Siegmar

    2011-10-01

    Human JPCs (jaw periosteal cells) are a promising source for the engineering of cell-based osteoinductive grafts in oral surgery. For this purpose, cell characteristics of this stem cell source should be elucidated in detail. Analysis of gene expression profiles may help us to evaluate key factors and cellular targets of JPC osteogenesis. Because little is known about the interplay of osteogenic-related components, we analysed the expression of different collagen types reflecting important players for extracellular matrix assembly and of TIMPs (tissue inhibitors of metalloproteinases) responsible for the inhibition of matrix degradation. Gene expression analyses using microarrays and quantitative RT-PCR (reverse transcription-PCR) during JPC osteogenesis revealed the induction of several collagen types' expression (VII, VIII, XI and XII), and some of them (types I, VIII and XI) seemed to be susceptible to BMP-2 (bone morphogenetic protein-2) that is known to be a potent osteogenic inducer of periosteal cells. Among the TIMPs, only TIMP-4 and RECK (reversion-inducing cysteine-rich protein with Kazal motifs) expressions were strongly up-regulated during JPC osteogenesis. Proteome profiler analysis of supernatants from untreated and differentiated JPCs confirmed the gene expression data in terms of TIMP expression. In summary, we identified new collagen types and TIMPs that seem to play important roles during the osteogenesis of jaw periosteal progenitor cells.

  2. Raman Spectroscopic Analyses of Jaw Periosteal Cell Mineralization.

    PubMed

    Brauchle, Eva; Carvajal Berrio, Daniel; Rieger, Melanie; Schenke-Layland, Katja; Reinert, Siegmar; Alexander, Dorothea

    2017-01-01

    To achieve safer patient treatments, serum-free cell culture conditions have to be established for cell therapies. In previous studies, we demonstrated that serum-free culture favored the proliferation of MSCA-1(+) osteoprogenitors derived from the jaw periosteum. In this study, the in vitro formation of bone-specific matrix by MSCA-1(+) jaw periosteal cells (JPCs, 3 donors) was assessed and compared under serum-free and serum-containing media conditions using the marker-free Raman spectroscopy. Based on a standard fluorescence assay, JPCs from one patient were not able to mineralize under serum-containing culture conditions, whereas the other cells showed similar mineralization levels under both conditions. Raman spectra from mineralizing MSCA-1(+) JPCs revealed higher levels of hydroxyapatite formation and higher mineral to matrix ratios under serum-free culture conditions. Higher carbonate to phosphate ratios and higher crystallinity in JPCs cultured under serum-containing conditions indicated immature bone formation. Due to reduced collagen production under serum-free conditions, we obtained significant differences in collagen maturity and proline to hydroxyproline ratios compared to serum-free conditions. We conclude that Raman spectroscopy is a useful tool for the assessment and noninvasive monitoring of in vitro mineralization of osteoprogenitor cells. Further studies should extend this knowledge and improve JPC mineralization by optimizing culture conditions.

  3. Posterior partially edentulous jaws, planning a rehabilitation with dental implants.

    PubMed

    Monteiro, Douglas R; Silva, Emily V F; Pellizzer, Eduardo P; Filho, Osvaldo Magro; Goiato, Marcelo C

    2015-01-16

    To discuss important characteristics of the use of dental implants in posterior quadrants and the rehabilitation planning. An electronic search of English articles was conducted on MEDLINE (PubMed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations (bone quantity and density), radiographic techniques, implant selection (number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning.

  4. Jaws and teeth of the earliest bony fishes.

    PubMed

    Botella, Hector; Blom, Henning; Dorka, Markus; Ahlberg, Per Erik; Janvier, Philippe

    2007-08-02

    Extant jawed vertebrates, or gnathostomes, fall into two major monophyletic groups, namely chondrichthyans (cartilaginous fishes) and osteichthyans (bony fishes and tetrapods). Fossil representatives of the osteichthyan crown group are known from the latest Silurian period, 418 million years (Myr) ago, to the present. By contrast, stem chondrichthyans and stem osteichthyans are still largely unknown. Two extinct Palaeozoic groups, the acanthodians and placoderms, may fall into these stem groups or the common stem group of gnathostomes, but their relationships and monophyletic status are both debated. Here we report unambiguous evidence for osteichthyan characters in jaw bones referred to the late Silurian (423-416-Myr-old) fishes Andreolepis hedei and Lophosteus superbus, long known from isolated bone fragments, scales and teeth, and whose affinities to, or within, osteichthyans have been debated. The bones are a characteristic osteichthyan maxillary and dentary, but the organization of the tooth-like denticles they bear differs from the large, conical teeth of crown-group osteichthyans, indicating that they can be assigned to the stem group. Andreolepis and Lophosteus are thus not only the oldest but also the most phylogenetically basal securely identified osteichthyans known so far.

  5. Bisphosphonate-related osteonecrosis of the jaw: the Florence experience

    PubMed Central

    Borgioli, Alberto; Duvina, Marco; Brancato, Leila; Viviani, Christian; Brandi, Maria Luisa; Tonelli, Paolo

    2007-01-01

    Aims. Bisphosphonates (BPs) are important therapeutic drugs in multiple myeloma and cancers with bone metastases. Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) has been described as a potential side effect of the last generation BPs. The Authors evaluated clinical features, preventing measures and treatment strategies. Patients and methods. The Authors retrospectively analyzed 19 patients affected by malignant cancer in endovenous treatment with BPs. Fourteen patients were treated with zoledronate, 1 with pamidronate and 4 with both drugs for breast cancer (9 patients), multiple myeloma (6 patients), prostatic cancer (3 patients) and colon cancer (1 patient). Results. The lenght of therapy was 5-36 months before osteonecrosis was observed; in 15 patients BRONJ involved the mandible, in 2 the maxilla and in 2 both jaws. The trigger factors were tooth extractions, inadequate removable total denture, basic and advanced surgery, root canal treatment. Ten patients received non-surgical treatment, 7 patients minor surgical procedures and 2 patients a partial maxillectomy. Healing was achieved in all maxillary localization, and in one mandibular localization with partial maxillectomy. Conclusions. Prevention is the best important phase in the management of this pathology. Risk factors are the type of bisphosphonate and the length of exposure, while dental surgical procedures are trigger factors. Conservative treatment seems to be the best way to control BRONJ, but bone resection and soft tissue closure have to be performed when the lesion is refractory to conservative approach. PMID:22460753

  6. Effective doses from cone beam CT investigation of the jaws

    PubMed Central

    Davies, J; Johnson, B; Drage, NA

    2012-01-01

    Objectives The purpose of the study was to calculate the effective dose delivered to the patient undergoing cone beam (CB) CT of the jaws and maxillofacial complex using the i-CAT Next Generation CBCT scanner (Imaging Sciences International, Hatfield, PA). Methods A RANDO® phantom (The Phantom Laboratory, Salem, NY) containing thermoluminence dosemeters were scanned 10 times for each of the 6 imaging protocols. Effective doses for each protocol were calculated using the 1990 and approved 2007 International Commission on Radiological Protection (ICRP) recommended tissue weighting factors (E1990, E2007). Results The effective dose for E1990 and E2007, respectively, were: full field of view (FOV) of the head, 47 μSv and 78 μSv; 13 cm scan of the jaws, 44 μSv and 77 μSv; 6 cm standard mandible, 35 μSv and 58 μSv; 6 cm high resolution mandible, 69 μSv and 113 μSv; 6 cm standard maxilla, 18 μSv and 32 μSv; and 6 cm high resolution maxilla, 35 μSv and 60 μSv. Conclusions Using the new generation of CBCT scanner, the effective dose is lower than the original generation machine for a similar FOV using the ICRP 2007 tissue weighting factors. PMID:22184626

  7. Robust 3D reconstruction system for human jaw modeling

    NASA Astrophysics Data System (ADS)

    Yamany, Sameh M.; Farag, Aly A.; Tazman, David; Farman, Allan G.

    1999-03-01

    This paper presents a model-based vision system for dentistry that will replace traditional approaches used in diagnosis, treatment planning and surgical simulation. Dentistry requires accurate 3D representation of the teeth and jaws for many diagnostic and treatment purposes. For example orthodontic treatment involves the application of force systems to teeth over time to correct malocclusion. In order to evaluate tooth movement progress, the orthodontists monitors this movement by means of visual inspection, intraoral measurements, fabrication of plastic models, photographs and radiographs, a process which is both costly and time consuming. In this paper an integrate system has been developed to record the patient's occlusion using computer vision. Data is acquired with an intraoral video camera. A modified shape from shading (SFS) technique, using perspective projection and camera calibration, is used to extract accurate 3D information from a sequence of 2D images of the jaw. A new technique for 3D data registration, using a Grid Closest Point transform and genetic algorithms, is used to register the SFS output. Triangulization is then performed, and a solid 3D model is obtained via a rapid prototype machine.

  8. Microbiota associated with chronic osteomyelitis of the jaws.

    PubMed

    Gaetti-Jardim Júnior, Elerson; Fardin, Angélica Cristiane; Gaetti-Jardim, Ellen Cristina; de Castro, Alvimar Lima; Schweitzer, Christiane Marie; Avila-Campos, Mario Julio

    2010-10-01

    Chronic osteomyelitis of maxilla and mandible is rare in industrialized countries and its occurrence in developing countries is associated with trauma and surgery, and its microbial etiology has not been studied thoroughly. The aim of this investigation was to evaluate the microbiota associated with osteomyelitis of mandible or maxilla from some Brazilian patients. After clinical and radiographic evaluation, samples of bone sequestra, purulent secretion, and biopsies of granulomatous tissues from twenty-two patients with chronic osteomyelitis of mandible and maxilla were cultivated and submitted for pathogen detection by using a PCR method. Each patient harbored a single lesion. Bacterial isolation was performed on fastidious anaerobe agar supplemented with hemin, menadione and horse blood for anaerobes; and on tryptic soy agar supplemented with yeast extract and horse blood for facultative bacteria and aerobes. Plates were incubated in anaerobiosis and aerobiosis, at 37(o)C for 14 and 3 days, respectively. Bacteria were cultivated from twelve patient samples; and genera Actinomyces, Fusobacterium, Parvimonas, and Staphylococcus were the most frequent. By PCR, bacterial DNA was detected from sixteen patient samples. The results suggest that cases of chronic osteomyelitis of the jaws are usually mixed anaerobic infections, reinforcing the concept that osteomyelitis of the jaws are mainly related to microorganisms from the oral environment, and periapical and periodontal infections may act as predisposing factors.

  9. A new 4-dimensional imaging system for jaw tracking.

    PubMed

    Lauren, Mark

    2014-01-01

    A non-invasive 4D imaging system that produces high resolution time-based 3D surface data has been developed to capture jaw motion. Fluorescent microspheres are brushed onto both tooth and soft-tissue areas of the upper and lower arches to be imaged. An extraoral hand-held imaging device, operated about 12 cm from the mouth, captures a time-based set of perspective image triplets of the patch areas. Each triplet, containing both upper and lower arch data, is converted to a high-resolution 3D point mesh using photogrammetry, providing the instantaneous relative jaw position. Eight 3D positions per second are captured. Using one of the 3D frames as a reference, a 4D model can be constructed to describe the incremental free body motion of the mandible. The surface data produced by this system can be registered to conventional 3D models of the dentition, allowing them to be animated. Applications include integration into prosthetic CAD and CBCT data.

  10. Aneurysmal Bone Cyst of the Jaws: Clinicopathological Study.

    PubMed

    Urs, Aadithya B; Augustine, Jeyaseelan; Chawla, Himanshi

    2014-12-01

    The aim of the present study was to analyze clinical, radiological and histopathological features of aneurysmal bone cysts (ABCs) of jaws. Archival data from 2009 to 2012 present in the Oral Pathology Department was retrieved and clinicopathological features of all the cases which had been previously diagnosed as ABC were analyzed in detail. Seven cases ranging in age from 10 to 50 years were included, in which maximum (5/7) cases were below 20 years. Ratio of presentation of lesion in male to female and in maxilla to mandible was 3:6 and 1:6 respectively. Swelling and pain were the most common presenting features. Variable presentation of the lesion was observed radiographically; although multilocular, well defined, bone expansion and perforation were the most common observations. Histopathological analysis revealed association of one case with ossifying fibroma and two cases with trabecular variety of juvenile ossifying fibroma. Predominance of solid variety was noted and other features like stroma, giant cells, nature of blood vessels, bone destruction and perforation and presence of any osteoid or calcified material was also accounted for. The current study showed association of two cases with trabecular variety of juvenile ossifying fibroma, which is a rare finding. ABCs of jaws, thus have varying patterns of presentation which are diagnostically challenging. A thorough examination of the incisional/excisional tissue is thus required to confirm the association with any other lesion which will affect the treatment plan for the patient.

  11. Microbiota associated with chronic osteomyelitis of the jaws

    PubMed Central

    Gaetti-Jardim Júnior, Elerson; Fardin, Angélica Cristiane; Gaetti-Jardim, Ellen Cristina; de Castro, Alvimar Lima; Schweitzer, Christiane Marie; Avila-Campos, Mario Julio

    2010-01-01

    Chronic osteomyelitis of maxilla and mandible is rare in industrialized countries and its occurrence in developing countries is associated with trauma and surgery, and its microbial etiology has not been studied thoroughly. The aim of this investigation was to evaluate the microbiota associated with osteomyelitis of mandible or maxilla from some Brazilian patients. After clinical and radiographic evaluation, samples of bone sequestra, purulent secretion, and biopsies of granulomatous tissues from twenty-two patients with chronic osteomyelitis of mandible and maxilla were cultivated and submitted for pathogen detection by using a PCR method. Each patient harbored a single lesion. Bacterial isolation was performed on fastidious anaerobe agar supplemented with hemin, menadione and horse blood for anaerobes; and on tryptic soy agar supplemented with yeast extract and horse blood for facultative bacteria and aerobes. Plates were incubated in anaerobiosis and aerobiosis, at 37oC for 14 and 3 days, respectively. Bacteria were cultivated from twelve patient samples; and genera Actinomyces, Fusobacterium, Parvimonas, and Staphylococcus were the most frequent. By PCR, bacterial DNA was detected from sixteen patient samples. The results suggest that cases of chronic osteomyelitis of the jaws are usually mixed anaerobic infections, reinforcing the concept that osteomyelitis of the jaws are mainly related to microorganisms from the oral environment, and periapical and periodontal infections may act as predisposing factors. PMID:24031586

  12. Human masticatory muscle activity and jaw position under experimental stress.

    PubMed

    Tsai, C-M; Chou, S-L; Gale, E N; McCall, W D

    2002-01-01

    The purpose of the present study was to determine whether stress induced a consistent pattern of increased electromyographic (EMG) activity in different masticatory muscles, and whether stress produced changes in jaw position. Thirty-five dental students at Taipei Medical College volunteered for this study. Mental arithmetic was used to create a stress condition and relaxation instruction was used to help relax the subjects. Subjects were asked to evaluate the stress they felt under each experimental condition with a visual analogue scale (VAS). Surface electrodes were used to monitor the EMG activities of the right masseter, right posterior temporalis and suprahyoid muscles. A kinesiograph was used to observe the jaw position. Data collected before mental arithmetic or relaxation monitored the baseline level. The VAS means were significantly increased during the stress condition and significantly decreased following relaxation, compared with the baseline. There was also a significant increase in EMG activity of all three muscles during mental arithmetic compared with baseline; different patterns of increased EMG activity were noticed in the three muscles under a continuous stress condition. Under stress, the incidence of tooth contact at intercuspal position was also increased.

  13. Convergence in morphology and masticatory function between the pharyngeal jaws of grass carp, Ctenopharyngodon idella, and oral jaws of amniote herbivores.

    PubMed

    Gidmark, Nicholas J; Tarrant, James C; Brainerd, Elizabeth L

    2014-06-01

    The cellulose-rich walls that protect plant cells are difficult to digest, and therefore mechanical food processing is a key aspect of herbivory across vertebrates. Cell walls are typically broken down by translation of flattened teeth in the occlusal plane (i.e. grinding) as part of a complex, rhythmic chewing stroke. The grass carp, Ctenopharyngodon idella, is a voracious, invasive herbivorous fish that relies solely on its pharyngeal teeth, located in the back of the throat, for mechanical processing of plant material. Here, we describe the musculoskeletal anatomy of the pharyngeal jaws of grass carp and use XROMM to quantify chewing kinematics and muscle strain. The pharyngeal jaws are suspended in a sling of 11 muscles and maintain no bony articulation with any other skeletal elements in the head. The jaws bear long, serrated teeth that are worn during use into flattened tooth cusps. Our kinematic data show that this wear is the result of the teeth being elevated into occlusion against the basioccipital process and keratinous chewing pad, not tooth-on-tooth occlusion. Pharyngeal jaw elevation results from large strains in the jaw elevator muscle, the levator arcus branchialis V, to drive a pulley-like mechanism that rotates the jaws about a pivot point at the symphysis between the left and right pharyngeal jaws. These complex, rhythmic jaw rotations translate the teeth laterally across the chewing surface throughout the occlusion phase. The grass carp chewing system is strikingly similar in gross morphology and masticatory function to herbivorous chewing strategies in other vertebrates.

  14. Development of 4D jaw movement visualization system for dental diagnosis support

    NASA Astrophysics Data System (ADS)

    Aoki, Yoshimitsu; Terajima, Masahiko; Nakasima, Akihiko

    2004-10-01

    A person with an asymmetric morphology of maxillofacial skeleton reportedly possesses an asymmetric jaw function and the risk to express temporomandibular disorder is high. A comprehensive analysis from the point of view of both the morphology and the function such as maxillofacial or temporomandibular joint morphology, dental occlusion, and features of mandibular movement pathways is essential. In this study, the 4D jaw movement visualization system was developed to visually understand the characteristic jaw movement, 3D maxillofacial skeleton structure, and the alignment of the upper and lower teeth of a patient. For this purpose, the 3D reconstructed images of the cranial and mandibular bones, obtained by computed tomography, were measured using a non-contact 3D measuring device, and the obtained morphological images of teeth model were integrated and activated on the 6 DOF jaw movement data. This system was experimentally applied and visualized in a jaw deformity patient and its usability as a clinical diagnostic support system was verified.

  15. Visualization and analysis of occlusion for human jaws using a "functionally generated path"

    NASA Astrophysics Data System (ADS)

    Myszkowski, Karol; Herder, Jens; Kunii, Tosiyasu L.; Ibusuki, Masumi

    1996-03-01

    Dynamic characteristics of occlusion during lower jaw motion are useful in the diagnosis of jaw articulation problems and in computer-aided design/ manufacture of teeth restorations. The Functionally Generated Path (FGP), produced as a surface which envelops the actual occlusal surface of the moving opponent jaw, can be used for compact representation of dynamic occlusal relations. In traditional dentistry FGP is recorded as a bite impression in a patient's mouth. We propose an efficient computerized technique for FGP reconstruction and validate it through implementation and testing. The distance maps between occlusal surfaces of jaws, calculated for multiple projection directions and accumulated for mandibular motion, provide information for FGP computation. Rasterizing graphics hardware is used for fast calculation of the distance maps. Real-world data are used: the scanned shape of teeth and the measured motion of the lower jaw. We show applications of FGP to analysis of the occlusion relations and occlusal surface design for restorations.

  16. Capture of Prey, Feeding, and Functional Anatomy of the Jaws in Velvet Worms (Onychophora).

    PubMed

    Mayer, Georg; Oliveira, Ivo S; Baer, Alexander; Hammel, Jörg U; Gallant, James; Hochberg, Rick

    2015-08-01

    Onychophorans are carnivorous, terrestrial invertebrates that occur in tropical and temperate forests of the Southern Hemisphere and around the Equator. Together with tardigrades, onychophorans are regarded as one of the closest relatives of arthropods. One of the most peculiar features of onychophorans is their hunting and feeding behavior. These animals secrete a sticky slime, which is ejected via a pair of slime-papillae, to entangle the prey. After the prey has been immobilized, its cuticle is punctured using a pair of jaws located within the mouth. These jaws constitute internalized appendages of the second body segment and are innervated by the deutocerebrum; thus, they are homologous to the chelicerae of chelicerates, and to the (first) antennae of myriapods, crustaceans, and insects. The jaws are also serial homologs of the paired claws associated with each walking limb of the trunk. The structure of the jaws is similar in representatives of the two major onychophoran subgroups, the Peripatidae and Peripatopsidae. Each jaw is characterized by an outer and an inner blade; while the outer blade consists only of a large principal tooth and up to three accessory teeth, the inner blade bears numerous additional denticles. These denticles are separated from the remaining part of the inner jaw by a diastema and a soft membrane only in peripatids. The onychophoran jaws are associated with large apodemes and specialized muscles that enable their movement. In contrast to the mandibles of arthropods, the onychophoran jaws are moved along, rather than perpendicular to, the main axis of the body. Our elemental analysis reveals an increased incorporation of calcium at the tip of each blade, which might provide rigidity, whereas there is no evidence for incorporation of metal or prominent mineralization. Stability of the jaw might be further facilitated by the cone-in-cone organization of its cuticle, as each blade consists of several stacked, cuticular elements. In this

  17. Effects of an Open Jaw Posture on Vowel Perception in the Aging Voice.

    PubMed

    Mautner, Helene D

    2016-11-01

    This study aimed to verify through an auditory-perceptual approach, whether an "open jaw" posture would result in improved speech quality for older adults. Forty normal-hearing listeners (20 males; 20 females) aged between 18 and 47 listened to vowel segments and performed two separate tasks: identifying vowels and comparing vowel clarity. Stimuli included vowels segmented from a sentence ("We saw two cars.") produced using a normal and an open jaw posture by 40 individuals aged between 30s and 80s. Three types of stimuli were presented: variable length and intensity, fixed length and variable intensity, and fixed length and normalized intensity. Mixed model analyses of variance were used to determine whether there was a jaw posture effect on the percentage of correct vowel identification. Chi-square tests were used to determine whether vowels produced with an open jaw posture were more likely to be identified as being "clearer." Open jaw posture resulted in higher rates of correct vowel identification, and vowels from contrast pairs were consistently judged as being "clearer" than vowels produced in normal jaw posture. Investigations on the effect of stimulus type revealed that the jaw-related improvement in speech quality was not solely due to an increase in intensity or length induced by an open jaw posture. Listeners assessing vowel identification and clarity in the aging voice were able to better differentiate among vowels spoken using an open jaw posture, and a greater number of vowels produced in an open jaw posture were perceived as sounding clearer. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  18. Prognosis factors in the treatment of bisphosphonate-related osteonecrosis of the jaw - Prognostic factors in the treatment of BRONJ

    PubMed Central

    Nakamichi, Ikuo; Yamashita, Yoshihiro; Yamamoto, Noriaki; Yamauchi, Kensuke; Nogami, Shinnosuke; Kaneuji, Takeshi; Mitsugi, Sho; Tanaka, Kenkou; Kataoka, Yoshihiro; Sakurai, Takuma; Kiyomiya, Hiroyasu; Miyamoto, Ikuya; Takahashi, Tetsu

    2014-01-01

    Objectives: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a relatively rare but serious side effect of bisphosphonate (BP)-based treatments. This retrospective study aimed to investigate the risk factors and predictive markers in cases where patients were refractory to a recommended conservative treatment offered in our hospital. Patients and Methods: This single-center study collated the medical records of all patients treated for BRONJ between 2004 and 2011. A complete medical history, including detailed questionnaires, was collected for all patients, focusing on identifying underlying risk factors, clinical features, location and bone marker levels of BRONJ. Results: The mean BRONJ remission rate was 57.6%, and the median duration of remission was seven months. Eighteen patients (34.6%) had persistent or progressive disease with a recommended conservative treatment for BRONJ. Notably, urinary cross-linked N-terminal telopeptide of type 1 collagen (NTX) levels in those resistant to conservative treatment tended to be lower than in patients that healed well. Conclusions: We confirm that a significant proportion of BRONJ sufferers are refractory to a recommended conservative treatment and find that anticancer drugs, periodontal disease, the level of bone exposure and the dosage of intravenous BPs (e.g. zoledronate) represent specific risk factors in BRONJ that may determine the success of a recommended conservative treatment. Additionally, the NTX levels might be able to be a prognostic factor for the conservative treatment of BRONJ; additional research is necessary. Key words:Bisphosphonate, osteonecrosis, jaw, prognostic, retrospective. PMID:24596631

  19. Intravenous bisphosphonate-related osteonecrosis of the jaws: Influence of coadjuvant antineoplastic treatment and study of buccodental condition

    PubMed Central

    Bagán, José; Poveda-Roda, Rafael

    2013-01-01

    Objectives: To determine whether coadjuvant antineoplastic treatment can influence the number and size of bone exposures among patients with intravenous bisphosphonate-related osteonecrosis of the jaws (iBRONJ), and to analyze the buccodental condition of these patients. Material and methods: The study sample comprised 67 patients with iBRONJ, 53 patients without iBRONJ receiving treatment with intravenous bisphosphonates, and 36 healthy subjects. In all three groups, measurements were made of the CAO index and of resting whole saliva and stimulated whole saliva. In the patients with iBRONJ, the size (cm) and number of bone exposures were recorded. The data obtained were subjected to analysis of variance (ANOVA), the Mann-Whitney U-test, and multivariate logistic regression analysis. Results: A total of 57.6% of the patients presented single bone exposure, 25.4% presented two, and 17% more than two exposures. The mean exposure size was 2.3±1.9 cm. Neither the bivariate analysis nor the multivariate multiple regression analysis found coadjuvant antineoplastic treatment to exert a statistically significant effect upon the number and size of bone exposures. On the other hand, there were statistically significant differences among the three study groups in relation to the CAO index (p=0.02) and the number of missing teeth (p=0.00). The resting whole saliva and stimulated whole saliva levels were similar in the three groups, though the patients with osteonecrosis of the jaws showed comparatively lower SWS levels. Conclusions: Coadjuvant antineoplastic treatment alone appears to exert no influence upon the size and number of bone exposures in iBRONJ. The patients with this disease show a higher CAO index and a larger number of missing teeth. Key words:Osteonecrosis of the jaws, bisphosphonates, bone exposure, CAO index, resting whole saliva, stimulated whole saliva. PMID:23229272

  20. Experimental and Numerical Investigation of Hypersonic Jaws Inlet

    NASA Astrophysics Data System (ADS)

    Dong, Hao; Wang, Cheng-Peng; Cheng, Ke-Ming

    In order to obtain the flow field characteristics and the influence of boundary layer, numerical simulations and wind tunnel tests are conducted for two streamline traced Jaws inlets at Mach number 7. The inlets are designed based on a flow field with 8-7 planar shock wave (the ramp in pitch plane is inclined at 8° to the free stream and in yaw plane is inclined at 7° to the free stream, yielding planar shocks). In the study, the static pressure distributions were measured and analyzed along the plane-symmetric centerline of the inlet with and without the boundary layer correction, respectively. Results show that boundary layer correction can obviously weaken the viscous influence to the inlet, increasing the mass flow coefficient and improving total pressure recovery.

  1. Osteoporosis and Bisphosphonate-Related Osteonecrosis of the Jaw Bone

    PubMed Central

    Villa, Alessandro; Castiglioni, Stefano; Peretti, Alessandro; Omodei, Marco; Ferrieri, Giovanni B.; Abati, Silvio

    2011-01-01

    The aim of this longitudinal study is to present data from 76 female patients treated with bisphosphonates (BPs) for postmenopausal osteoporosis and referred to the Unit of Oral Diagnosis and Day Surgery of the University of Milano for diagnosis and treatment. All patients received a thorough oral examination. The diagnosis of osteonecrosis of the jaw bone (ONJ) was made from radiographic and clinical findings. 9% of individuals had BRONJ at first visit. Patients with dental or periodontal abscess were significantly more likely to develop BRONJ (OR: 2.9, 95% CI 0.5–15.9). Patients with osteoporosis receiving BPs may develop BRONJ, especially in the presence of an active infectious process in the mouth. Clinicians should carefully follow up on individuals receiving bisphosphonates therapy to avoid the occurrence of osteonecrotic lesions. PMID:22389800

  2. Dense bone island of the jaw: a case report

    PubMed Central

    MARIANI, G. CERULLI; FAVARETTI, F.; LAMAZZA, L.; DE BIASE, A.

    2009-01-01

    SUMMARY The “Dense Bone Island” (DBI) is a radiopaque lesion referred in leterature as idiopathic osteosclerosis, enostosis, focal osteosclerosis, periapical osteopetrosis, and bone scar. The DBI are accidentally found in routinary Xray of bone structures. In the maxillary bones, often localized in the mandible, especially in the molar region, with a reported incidence ranging from 2.3 to 9.7%. DBI does not seem to develop until the first phase of adolescence and it is usually found in adolescents and in young adults. In 40% of cases DBI seems to increase in size after a 10 year follow-up, because the DBI found in jaws and in long bones seem to increase proportionally to the bone growth. A case of a 26 years old patient and the surgical treatment is presented. This is the first reported case where complete X-ray Orthopantomography follow-up showed the evolution of the lesion since its onset. PMID:23285342

  3. Dense bone island of the jaw: a case report.

    PubMed

    Mariani, G Cerulli; Favaretti, F; Lamazza, L; DE Biase, A

    2008-07-01

    The "Dense Bone Island" (DBI) is a radiopaque lesion referred in leterature as idiopathic osteosclerosis, enostosis, focal osteosclerosis, periapical osteopetrosis, and bone scar. The DBI are accidentally found in routinary Xray of bone structures. In the maxillary bones, often localized in the mandible, especially in the molar region, with a reported incidence ranging from 2.3 to 9.7%. DBI does not seem to develop until the first phase of adolescence and it is usually found in adolescents and in young adults. In 40% of cases DBI seems to increase in size after a 10 year follow-up, because the DBI found in jaws and in long bones seem to increase proportionally to the bone growth. A case of a 26 years old patient and the surgical treatment is presented. This is the first reported case where complete X-ray Orthopantomography follow-up showed the evolution of the lesion since its onset.

  4. Osteonecrosis of the jaw in cancer patients receiving IV bisphosphonates.

    PubMed

    Van Poznak, Catherine; Estilo, Cherry

    2006-08-01

    Cases of osteonecrosis of the jaw (ONJ) have been reported with an increasing frequency over the past few years. ONJ is most often identified in patients with cancer who are receiving intravenous bisphosphonate therapy but it has also been diagnosed in patients receiving oral bisphosphonates for nonmalignant conditions. The condition involves exposed bone of the maxilla or mandible. Although it is often associated with a recent dental surgical procedure, spontaneous ONJ can also occur. Patients commonly present with symptoms. Through case reporting and clinical experience, there is a suggestion that the incidence of ONJ in patients with cancer receiving intravenous bisphosphonates ranges between 1% and 10%. Management of ONJ focuses on maximizing oral health, conservative actions with mouth rinses, antibiotics, and avoidance of unnecessary invasive dental procedures. The currently available data on ONJ are reviewed here.

  5. Restoration of jaw bone tissue defect using osteoplastic material.

    PubMed

    Grdzelidze, T; Machavariani, A; Menabde, G; Gvelesiani, N; Amiranashvili, I

    2014-02-01

    The aim of the study was to repair mandibular bone defect using BIO-OSS artificial bone implantation. The experiment was conducted on 30 white laboratory rats. Defect in the bone of lower jaw was created surgically. Animals were divided into 2 groups. 15 animals were allocated in control group. Another 15 animals were allocated in the BIO-OSS treatment group. analysis revealed bone defect in 6-month after modeling of bone defect. There was no pronounced proliferation of connective tissue visible in the defect area. Treatment group: In the samples of treated group, BIO-OSS bone mass formed basophilic fiber-like structures. It was surrounded with the thin proliferative connective and granulation tissues. proposed technique of bone defect reconstruction is an effective and sustainable method and can be recommended for wider use in clinical practice.

  6. The innervation of the zebrafish pharyngeal jaws and teeth

    PubMed Central

    Crucke, Jeroen; Van de Kelft, Annelore; Huysseune, Ann

    2015-01-01

    Zebrafish ( Danio rerio) teeth are increasingly used as a model to study odontogenesis in non-mammalians. Using serial semi-thin section histology and immunohistochemistry, the nerves innervating the pharyngeal jaws and teeth have been identified. The last pair of branchial arches, which are non-gill bearing but which carry the teeth, are innervated by an internal branch of a post-trematic ramus of the vagal nerve. Another, external, branch is probably responsible for the motor innervation of the branchiomeric musculature. Nerve fibres appear in the pulp cavity of the teeth only late during cytodifferentiation, and are therefore likely not involved in early steps of tooth formation. The precise role of the nervous system during continuous tooth replacement remains to be determined. Nonetheless, this study provides the necessary morphological background information to address this question. PMID:26018453

  7. Posterior partially edentulous jaws, planning a rehabilitation with dental implants

    PubMed Central

    Monteiro, Douglas R; Silva, Emily V F; Pellizzer, Eduardo P; Filho, Osvaldo Magro; Goiato, Marcelo C

    2015-01-01

    AIM: To discuss important characteristics of the use of dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE (PubMed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. RESULTS: One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations (bone quantity and density), radiographic techniques, implant selection (number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. CONCLUSION: The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning. PMID:25610852

  8. Understanding bisphosphonates and osteonecrosis of the jaw: uses and risks.

    PubMed

    Rosini, S; Rosini, S; Bertoldi, I; Frediani, B

    2015-09-01

    Bisphosphonates are chemically stable analogs of pyrophosphate compounds, which have been used to treat multiple disorders of calcium metabolism. Although bisphosphonates have been employed for many years and have demonstrated an excellent safety profile, severe osteonecrosis of the jaw (ONJ) has been described in patients with bone metastases who have been treated with bisphosphonates. In this review we describe the reasons for ONJ and discuss the varying effects of different bisphosphonates on the development of ONJ. Bisphosphonates tend to accumulate in bone, subject to remodeling (such as the jaw) and can affect osteoclast-mediated bone resorption and osteoclast formation, leading to the osteonecrosistic phenomenon. Risk factors for previously -treated patients include the type of bisphosphonates (amino or non-amino), length of treatment and route of administration, the presence of co-morbidities and/or treatment with immune-suppressing drugs, and the presence of other risk factors in addition to the type of intervention required. In oncological patients currently in treatment with receiving intravenous bisphosphonates, greater consideration must be taken depending on the length of treatment already undertaken and concomitant therapies. In these patients, a preventive dental surgery visit and examination of the case would be advisable prior to beginning treatment with bisphosphonates. Practical approaches in the prevention of ONJ include thorough pre-treatment evaluation and performing any preventative procedures (treat periodontal conditions, extract loose teeth, provide protective and endodontic therapies); initiating amino-bisphosphonates only after any gum tissue damage has healed; establishing a regimented check-up schedule and hygieneic precautions the patient can take; and during bisphosphonate treatment conduct any dental procedures in the least invasive manner during bisphosphonate treatment.

  9. Craniofacial pain and jaw-muscle activity during sleep.

    PubMed

    Yachida, W; Castrillon, E E; Baad-Hansen, L; Jensen, R; Arima, T; Tomonaga, A; Ohata, N; Svensson, P

    2012-06-01

    This study compared the jaw-muscle electromyographic (EMG) activity during sleep in patients with craniofacial pain (n = 63) or no painful conditions (n = 52) and between patients with tension-type headache (TTH: n = 30) and healthy control individuals (n = 30). All participants used a portable single-channel EMG device (Medotech A/S) for four nights. There was no significant difference in EMG activity between craniofacial pain (24.5 ± 17.9 events/hr) and no painful conditions (19.7 ± 14.5), or between TTH (20.8 ± 15.0) and healthy control individuals (15.2 ± 11.6, p >.050). There were positive correlations between EMG activity and number of painful muscles (r = 0.188; p = 0.044), characteristic pain intensity (r = 0.187; p = 0.046), McGill Pain Questionnaire (r = 0.251; p = 0.008), and depression scores (r = 0.291; p = 0.002). Patients with painful conditions had significantly higher night-to-night variability compared with pain-free individuals (p < 0.050). This short-term observational study suggests that there are no major differences between patients with different craniofacial pain conditions and pain-free individuals in terms of jaw-muscle EMG activity recorded with a single-channel EMG device during sleep. However, some associations may exist between the level of EMG activity and various parameters of craniofacial pain. Longitudinal studies are warranted to further explore the relationship between sleep bruxism and craniofacial pain.

  10. Two cases of multiple ossifying fibromas in the jaws

    PubMed Central

    2014-01-01

    Background The clinicopathologic characteristics of multiple ossifying fibroma (OF) are unclear due to the condition’s rarity, making diagnosis challenging. Sporadic multiple OFs must be distinguished from hyperparathyroidism-jaw tumour syndrome (HPT-JT) related OF and other fibro-osseous lesions. Methods Multiple OF cases were identified from ossifying fibroma cases. Clinical data including age, sex, anatomic site, radiographic features, clinical impression, treatment and available follow-up data as well as serum calcium, phosphorus, and parathyroid hormone (PTH) were recorded. GNAS and HRPT2 genetic mutations were examined in the two present cases. Case reports of sporadic multiple ossifying fibroma and HPT-JT-related OF were also reviewed. Results The two present cases were confirmed as sporadic multiple OF, with no genetic GNAS and HRPT2 mutations found. The incidence of sporadic multiple ossifying fibroma was 2.0% (2/102). The total 18 sporadic multiform OF cases were characterized as followed: 13 (72.2%) female; 5 (27.8%) male; mean age 28.6 years; 2/16 (11.1%) cases only in the mandible; 4/18 (22.2%) cases only in the maxilla; and 12/18 (66.7%) cases in both the maxilla and mandible. Radiographically, the lesions were radiolucent in 5/18 (27.8%) cases and mixed density in 13/18 (72.2%) cases. Along with 24 cases of HPT-JT related OF were reviewed, sixteen (66.7%) patients were diagnosed with a single lesion, and 8 patients (33.3%) were diagnosed with multiple jaw lesions. Conclusions Sporadic multiple OFs are very rare, but must be distinguished from HPT-JT related OF. We strongly recommend that patients diagnosed with multiple ossifying fibromas receive serum PTH testing and mutation screening of HRPT2. Virtual slides http://www.diagnosticpathology.diagnomx.eu/vs/1194507146115753 PMID:24678936

  11. Posterior scissors-bite: masticatory jaw movement and muscle activity.

    PubMed

    Tomonari, H; Kubota, T; Yagi, T; Kuninori, T; Kitashima, F; Uehara, S; Miyawaki, S

    2014-04-01

    Scissors-bite is a malocclusion characterised by buccal inclination or buccoversion of the maxillary posterior tooth and/or linguoclination or linguoversion of the mandibular posterior tooth. This type of malocclusion causes reduced contact of the occlusal surfaces and can cause excessive vertical overlapping of the posterior teeth. This case-control study is the first to evaluate both masticatory jaw movement and masseter and temporalis muscle activity in patients with unilateral posterior scissors-bite. Jaw movement variables and surface electromyography data were recorded in 30 adult patients with unilateral posterior scissors-bite malocclusion and 18 subjects with normal occlusion in a case-control study. The chewing pattern on the scissors-bite side significantly differed from that of the non-scissors-bite side in the patients and of the right side in the normal subjects. These differences included a narrower chewing pattern (closing angle, P < 0.01; cycle width, P < 0.01), a longer closing duration (P < 0.05), a slower closing velocity (P < 0.01) and lower activities of both the temporalis (P < 0.05) and the masseter (P < 0.05) muscles on the working side. In 96% of the patients with unilateral posterior scissors-bite, the preferred chewing side was the non-scissors-bite side (P = 0.005). These findings suggest that scissors-bite malocclusion is associated with the masticatory chewing pattern and muscle activity, involving the choice of the preferred chewing side in patients with unilateral posterior scissors-bite.

  12. The Rise of Jaw Protrusion in Spiny-Rayed Fishes Closes the Gap on Elusive Prey.

    PubMed

    Bellwood, David R; Goatley, Christopher H R; Bellwood, Orpha; Delbarre, Daniel J; Friedman, Matt

    2015-10-19

    Jaw protrusion is one of the most important innovations in vertebrate feeding over the last 400 million years [1, 2]. Protrusion enables a fish to rapidly decrease the distance between itself and its prey [2, 3]. We assessed the evolution and functional implications of jaw protrusion in teleost fish assemblages from shallow coastal seas since the Cretaceous. By examining extant teleost fishes, we identified a robust morphological predictor of jaw protrusion that enabled us to predict the extent of jaw protrusion in fossil fishes. Our analyses revealed increases in both average and maximum jaw protrusion over the last 100 million years, with a progressive increase in the potential impact of fish predation on elusive prey. Over this period, the increase in jaw protrusion was initially driven by a taxonomic restructuring of fish assemblages, with an increase in the proportion of spiny-rayed fishes (Acanthomorpha), followed by an increase in the extent of protrusion within this clade. By increasing the ability of fishes to catch elusive prey [2, 4], jaw protrusion is likely to have fundamentally changed the nature of predator-prey interactions and may have contributed to the success of the spiny-rayed fishes, the dominant fish clade in modern oceans [5].

  13. Osteonecrosis of the jaws: a review and update in etiology and treatment.

    PubMed

    Ribeiro, Guilherme H; Chrun, Emanuely S; Dutra, Kamile L; Daniel, Filipe I; Grando, Liliane J

    2017-06-24

    Osteonecrosis of the jaws can result either from radiation, used in radiotherapy for treatment of malignant tumors, or medications used for bone remodeling and anti-angiogenesis such as bisphosphonates. These conditions can be associated with triggering factors such as infection, trauma and decreased vascularity. The management of patients with osteonecrosis of the jaws requires caution since there is no specific treatment that acts isolated and decidedly. However, different treatment modalities can be employed in an associated manner to control and stabilize lesions. To review the current knowledge on etiology and management of osteonecrosis of the jaws, both radio-induced and medication-related, aiming to improve knowledge of professionals seeking to improve the quality of life of their patients. Literature review in PubMed as well as manual search for relevant publications in reference list of selected articles. Articles in English ranging from 1983 to 2017, which assessed osteonecrosis of the jaws as main objective, were selected and analyzed. Infections, traumas and decreased vascularity have a triggering role for osteonecrosis of the jaws. Prophylactic and/or stabilizing measures can be employed in association with therapeutic modalities to properly manage osteonecrosis of the jaws patients. Selecting an appropriate therapy for osteonecrosis of the jaws management based on current literature is a rational decision that can help lead to a proper treatment plan. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  14. Scaling of jaw muscle size and maximal bite force in finches.

    PubMed

    van der Meij, M A A; Bout, R G

    2004-07-01

    Fringillids and estrildids differ in their husking performance on hard closed-shelled seeds, which are cracked before they are eaten. The time required to husk a seed is directly related to seed hardness, and husking time is therefore expected to be related to bite force as well. We investigated whether there is a significant difference in jaw muscle mass and maximal bite force between fringillids and estrildids. The analysis shows that fringillids have relatively larger jaw muscles than estrildids and are able to produce higher bite forces than estrildids of the same body size. This difference in jaw muscle mass mainly results from a difference in jaw closing muscles. Compared with other birds, the jaw muscles of both fringillids and estrildids scale strongly positively allometric with body size. Muscle fibre length scales negatively allometric with body size, which results in relatively high muscle and bite forces. Comparison with the scarce data available for other trophic groups suggests that the scaling of jaw muscle size depends on diet and that jaw muscle size in finches is an adaptation to their feeding behaviour.

  15. Biting intentions modulate digastric reflex responses to sudden unloading of the jaw.

    PubMed

    Johansson, Anders S; Pruszynski, J Andrew; Edin, Benoni B; Westberg, Karl-Gunnar

    2014-09-01

    Reflex responses in jaw-opening muscles can be evoked when a brittle object cracks between the teeth and suddenly unloads the jaw. We hypothesized that this reflex response is flexible and, as such, is modulated according to the instructed goal of biting through an object. Study participants performed two different biting tasks when holding a peanut half stacked on a chocolate piece between their incisors. In one task, they were asked to split the peanut half only (single-split task), and in the other task, they were asked to split both the peanut and the chocolate in one action (double-split task). In both tasks, the peanut split evoked a jaw-opening muscle response, quantified from electromyogram (EMG) recordings of the digastric muscle in a window 20-60 ms following peanut split. Consistent with our hypothesis, we found that the jaw-opening muscle response in the single-split trials was about twice the size of the jaw-opening muscle response in the double-split trials. A linear model that predicted the jaw-opening muscle response on a single-trial basis indicated that task settings played a significant role in this modulation but also that the presplit digastric muscle activity contributed to the modulation. These findings demonstrate that, like reflex responses to mechanical perturbations in limb muscles, reflex responses in jaw muscles not only show gain-scaling but also are modulated by subject intent.

  16. Molecular and cellular changes associated with the evolution of novel jaw muscles in parrots.

    PubMed

    Tokita, Masayoshi; Nakayama, Tomoki; Schneider, Richard A; Agata, Kiyokazu

    2013-02-07

    Vertebrates have achieved great evolutionary success due in large part to the anatomical diversification of their jaw complex, which allows them to inhabit almost every ecological niche. While many studies have focused on mechanisms that pattern the jaw skeleton, much remains to be understood about the origins of novelty and diversity in the closely associated musculature. To address this issue, we focused on parrots, which have acquired two anatomically unique jaw muscles: the ethmomandibular and the pseudomasseter. In parrot embryos, we observe distinct and highly derived expression patterns for Scx, Bmp4, Tgfβ2 and Six2 in neural crest-derived mesenchyme destined to form jaw muscle connective tissues. Furthermore, immunohistochemical analysis reveals that cell proliferation is more active in the cells within the jaw muscle than in surrounding connective tissue cells. This biased and differentially regulated mode of cell proliferation in cranial musculoskeletal tissues may allow these unusual jaw muscles to extend towards their new attachment sites. We conclude that the alteration of neural crest-derived connective tissue distribution during development may underlie the spatial changes in jaw musculoskeletal architecture found only in parrots. Thus, parrots provide valuable insights into molecular and cellular mechanisms that may generate evolutionary novelties with functionally adaptive significance.

  17. Effect of three different jaw positions on postural stability during standing

    PubMed Central

    Alghadir, Ahmad H.; Zafar, Hamayun; Iqbal, Zaheen A.

    2015-01-01

    Summary Studies in the literature show that jaw and neck regions are linked anatomically, biomechanically and neurologically. Voluntary clenching has been shown to improve muscle strength and performance of various motor tasks. Information from the neck sensory-motor system is reported to be important for posture. Hence it is reasonable to believe that activation of the jaw sensory-motor system has the potential to modulate posture. In a sample of 116 healthy subjects, we compared center of gravity (COG) velocity during quiet standing on a foam surface during three test positions: i) resting jaw, ii) open jaw, and iii) clenching; these were tested in two conditions: with eyes open and with eyes closed. The COG velocity decreased significantly during clenching in comparison to both open and resting jaw positions (p<0.0001). This suggests that the jaw sensory-motor system can modulate postural mechanisms. We conclude that jaw clenching can enhance postural stability during standing on an unstable surface in both the presence and absence of visual input in healthy adults and suggest that this should be taken into consideration in treatment and rehabilitation planning for patients with postural instability. PMID:26329542

  18. Changes in jaw muscle EMG activity and pain after third molar surgery.

    PubMed

    Ernberg, M; Schopka, J H; Fougeront, N; Svensson, P

    2007-01-01

    Limited jaw-opening capacity is frequently encountered following third molar surgery and may impair function. The aim of this study was to investigate the electromyographic (EMG) activity in jaw muscles after third molar surgery to obtain more insight into the mechanisms of restrictions in jaw opening. Twenty subjects were examined before, 24 h and 1 week after surgery. Ten healthy controls were subjected to the same examination at two different occasions for intersession variability. The EMG activity of the masseter and anterior digastricus muscles was recorded at different jaw positions and during maximum voluntary clenching. Pain intensity was assessed at rest and during movements. The EMG activity in the jaw muscles increased with opening level (P < 0.01), but did not change after surgery. In contrast, the EMG activity during clenching was decreased in all muscles after surgery (P < 0.05). The pain intensity after surgery increased with jaw opening level (P < 0.001), but was in general not correlated to EMG level. Pain intensity during clenching was increased after surgery (P < 0.001), but not correlated to EMG level. The EMG activity did not change between visits in the control group. In conclusion, the results indicate that third molar surgery does not influence the EMG activity in the masseter and anterior digastricus muscles during various levels of static jaw opening, but decreases the EMG activity during clenching. However, these changes are not influenced by pain intensity. The results have implications for the understanding of the phenomenon of trismus.

  19. Morphology does not predict performance: jaw curvature and prey crushing in durophagous stingrays.

    PubMed

    Kolmann, Matthew A; Crofts, Stephanie B; Dean, Mason N; Summers, Adam P; Lovejoy, Nathan R

    2015-12-01

    All stingrays in the family Myliobatidae are durophagous, consuming bivalves and gastropods, as well as decapod crustaceans. Durophagous rays have rigid jaws, flat teeth that interlock to form pavement-like tooth plates, and large muscles that generate bite forces capable of fracturing stiff biological composites (e.g. mollusk shell). The relative proportion of different prey types in the diet of durophagous rays varies between genera, with some stingray species specializing on particular mollusk taxa, while others are generalists. The tooth plate module provides a curved occlusal surface on which prey is crushed, and this curvature differs significantly among myliobatids. We measured the effect of jaw curvature on prey-crushing success in durophagous stingrays. We milled aluminum replica jaws rendered from computed tomography scans, and crushed live mollusks, three-dimensionally printed gastropod shells, and ceramic tubes with these fabricated jaws. Our analysis of prey items indicate that gastropods were consistently more difficult to crush than bivalves (i.e. were stiffer), but that mussels require the greatest work-to-fracture. We found that replica shells can provide an important proxy for investigations of failure mechanics. We also found little difference in crushing performance between jaw shapes, suggesting that disparate jaws are equally suited for processing different types of shelled prey. Thus, durophagous stingrays exhibit a many-to-one mapping of jaw morphology to mollusk crushing performance. © 2015. Published by The Company of Biologists Ltd.

  20. Anteroposterior dental arch and jaw-base relationships in a population sample.

    PubMed

    Zhou, Lei; Mok, Chung-Wai; Hägg, Urban; McGrath, Colman; Bendeus, Margareta; Wu, John

    2008-11-01

    To determine the association between the anteroposterior relationship of the dental arch and the anteroposterior relationship of the jaw-base in a Chinese population sample. Orthodontic casts and lateral cephalograms were obtained from a random sample of 405 twelve-year-old Chinese children from a population survey in Hong Kong. Angle's classification was used to assess the dental arch relationship from orthodontic casts. The jaw-base relationship was assessed from the lateral cephalograms using angular (ANB angle) and linear (Wits analysis) measurements. The correlation between the anteroposterior dental arch and jaw-base relationships was assessed. The anteroposterior dental arch did coincide with the jaw-base relationships, as expressed by the ANB angle in 61%, the Wits analysis in 67%, and with both in 53%. The jaw-base relationship assessed with the Wits analysis was more significantly associated with the dental arch relationship (P < .001) than that assessed with the ANB angle (P < .01). The correlation coefficient between the ANB angle and the Wits appraisal was .65 for the combined sample, and .60, .64, and .67 for Class I, II, and III dental arch relationships. In this population, the anteroposterior relationship of the dental arch and jaw-base fail to match in at least one out of every three individuals. Linear measurement of anteroposterior jaw-base relationships is a more valid reflection of the dental arch relationship than angular measurements.

  1. The speech focus position effect on jaw-finger coordination in a pointing task.

    PubMed

    Rochet-Capellan, Amélie; Laboissière, Rafael; Galván, Arturo; Schwartz, Jean-Luc

    2008-12-01

    This article investigates jaw-finger coordination in a task involving pointing to a target while naming it with a CVCV (e.g., /papa/) versus CVCV (e.g., /papa/) word. According to the authors' working hypothesis, the pointing apex (gesture extremum) would be synchronized with the apex of the jaw-opening gesture corresponding to the stressed syllable. Jaw and finger motions were recorded using Optotrak (Northern Digital, Waterloo, Ontario, Canada). The effects of stress position on jaw-finger coordination were tested across different target positions (near vs. far) and different consonants in the target word (/t/ vs. /p/). Twenty native Portuguese Brazilian speakers participated in the experiment (all conditions). Jaw response starts earlier, and finger-target alignment period is longer for CVCV words than for CVCV ones. The apex of the jaw-opening gesture for the stressed syllable appears synchronized with the onset of the finger-target alignment period (corresponding to the pointing apex) for CVCV words and with the offset of that period for CVCV words. For both stress conditions, the stressed syllable occurs within the finger-target alignment period because of tight finger-jaw coordination. This result is interpreted as evidence for an anchoring of the speech deictic site (part of speech that shows) in the pointing gesture.

  2. Marcus Gunn jaw-winking phenomenon: a new supplemental test in the preoperative evaluation.

    PubMed

    Wong, J F; Thériault, J F; Bouzouaya, C; Codère, F

    2001-11-01

    To introduce a new method for the evaluation of Marcus Gunn jaw-winking ptosis that more precisely defines the severity of blepharoptosis. A retrospective review of 16 consecutive patients with Marcus Gunn jaw-winking ptosis presenting to our institution between 1993 to 1999 was performed. The position of the affected eyelid was observed after applying a technique of jaw immobilization and disruption of fusion with temporary occlusion of the ipsilateral side. In patients presenting with mild to moderate Marcus Gunn jaw-winking, the majority (62.5%) demonstrated a positive test, uncovering complete or near complete ptosis. Test results were partially positive in 3 patients (18.8%) with increased but not complete ptosis and negative in 3 patients (18.8%) with no change in eyelid position. Blepharoptosis associated with Marcus Gunn jaw-winking phenomenon is often more severe than found by conventional clinical evaluation. This finding may explain the frequent undercorrection and unpredictable results following levator resection. In patients exhibiting a positive jaw-winking ptosis test, disappointing outcomes with levator resection may be avoided by instead proceeding with a frontalis suspension with levator disinsertion as recommended for ptosis with severe jaw winking.

  3. Jaw movements in patients with a history of pain: an exploratory study.

    PubMed

    Bhaskaracharya, M; Memon, S M; Whittle, T; Murray, G M

    2015-01-01

    The aims were to determine whether individuals with a past history of pain exhibit (i) altered jaw movement (e.g. reduced amplitude, increased jaw movement variability) in comparison with matched asymptomatic controls, and (ii) correlations between psychological measures (e.g. catastrophising) and altered jaw movement variables. Sixteen participants with a history of trigeminal neuropathic pain (TNP) and 15 age- and gender-matched healthy controls had jaw movements recorded during open/close, free gum chewing and chewing at standardised rates. All completed the Pain Catastrophising Scale (PCS), the Pain Self-Efficacy Questionnaire (PSEQ), and the Depression, Anxiety and Stress Scales (DASS). Velocity and amplitude for open/close and chewing, as well as variability, bias and mean square error for open/close jaw movements were compared between groups. Spearman's rank correlation coefficient was used to relate kinematic variables with psychological variables. Statistical significance: P < 0·05. There were no significant differences in mean jaw velocity and amplitude between the TNP and control groups during the open/close jaw movements or free or standardised chewing. In comparison with control, the TNP participants exhibited significantly greater variability, bias and/or mean square error during slow and/or fast opening, and significantly greater variance in velocity and/or amplitude during free and standardised chewing. There were significant negative correlations between PCS scores and velocity and/or amplitude of free and/or standardised chewing. This exploratory study suggests that individuals with a history of pain have altered patterns of jaw movements in comparison with asymptomatic control participants and that catastrophising may play a role in the manifestation of these altered jaw movements.

  4. Asymmetric Requirement of Surface Epithelial β-Catenin During the Upper and Lower Jaw Development

    PubMed Central

    Sun, Ye; Teng, Ian; Huo, Randi; Rosenfeld, Michael G; Olson, Lorin E; Li, Xiaokun; Li, Xue

    2012-01-01

    Background: Intercellular communication between epithelial and mesenchymal cells is central to mammalian craniofacial development. β-catenin is the gateway of canonical Wnt signaling, one of the major evolutionarily conserved cell–cell communication pathways in metazoa. In this study, we report an unexpected stage- and tissue-specific function of β-catenin during mammalian jaw development. Results: Using a unique mouse genetic tool, we have discovered that epithelial β-catenin is essential for lower jaw formation, while attenuation of β-catenin is required for proper upper jaw development. Changes in β-catenin in vivo alter major epithelial Fgf8, Bmp4, Shh, and Edn1 signals, resulting in partial transcriptional reprogramming of the neural crest-derived mesenchyme, the primary source of jawbones. Conclusions: The Wnt/β-catenin signal coordinates expression of multiple epithelial signals and has stage-specific asymmetric functions during mammalian upper and lower jaw development. In addition, these findings suggest that evolutionary changes of the canonical Wnt/β-catenin signaling pathway may lead to innovation of jaws. Developmental Dynamics 241:663–674, 2012. © 2012 Wiley Periodicals, Inc. Key Findings Mammalian epithelial Wnt/β-catenin signaling has asymetric functions in the upper and lower jaw development. The canonical Wnt/β-catenin pathway coordinates expression of multiple epithelial signals including Fgf8, Bmp4, Shh, and Edn1. Activation of epithelial Wnt/β-catenin signaling induces molecular transformation of the upper jaw to the lower jaw mesenchymal phenotype. Evolutionary changes of the canonical Wnt/β-catenin signaling pathway may lead to innovation of jaws. PMID:22354888

  5. Raptorial jaws in the throat help moray eels swallow large prey.

    PubMed

    Mehta, Rita S; Wainwright, Peter C

    2007-09-06

    Most bony fishes rely on suction mechanisms to capture and transport prey. Once captured, prey are carried by water movement inside the oral cavity to a second set of jaws in the throat, the pharyngeal jaws, which manipulate the prey and assist in swallowing. Moray eels display much less effective suction-feeding abilities. Given this reduction in a feeding mechanism that is widespread and highly conserved in aquatic vertebrates, it is not known how moray eels swallow large fish and cephalopods. Here we show that the moray eel (Muraena retifera) overcomes reduced suction capacity by launching raptorial pharyngeal jaws out of its throat and into its oral cavity, where the jaws grasp the struggling prey animal and transport it back to the throat and into the oesophagus. This is the first described case of a vertebrate using a second set of jaws to both restrain and transport prey, and is the only alternative to the hydraulic prey transport reported in teleost fishes. The extreme mobility of the moray pharyngeal jaws is made possible by elongation of the muscles that control the jaws, coupled with reduction of adjacent gill-arch structures. The discovery that pharyngeal jaws can reach up from behind the skull to grasp prey in the oral jaws reveals a major innovation that may have contributed to the success of moray eels as apex predators hunting within the complex matrix of coral reefs. This alternative prey transport mode is mechanically similar to the ratcheting mechanisms used in snakes--a group of terrestrial vertebrates that share striking morphological, behavioural and ecological convergence with moray eels.

  6. Extensive jaw mobility in suckermouth armored catfishes (Loricariidae): a morphological and kinematic analysis of substrate scraping mode of feeding.

    PubMed

    Adriaens, Dominique; Geerinckx, Tom; Vlassenbroeck, Jelle; Van Hoorebeke, Luc; Herrel, Anthony

    2009-01-01

    Loricariidae, or suckermouth armored catfishes, possess upper and lower jaws that are ventrally oriented and that bear teeth that touch the substrate from which algae and other food items are scraped. The ventral orientation and the highly specialized morphology of the jaws, characterized by protrusible upper jaws and left-right decoupled lower jaws, are observed in Pterygoplichthys disjunctivus, the species investigated here. Kinematic data of the scraping feeding movements, obtained by external high-speed and x-ray recordings, are used to quantify jaw movement, especially to test for upper jaw mobility and versatility during substrate scraping. Our results show that the mobility of the jaws is indeed high compared with what is standard for catfishes. The upper jaw's ability to perform a substantial degree of rostrocaudal movement is quite unique for catfishes. The ventromedially oriented lower jaws, with the teeth and the coronoid process at opposite sides, display an extensive mobility: they rotate around the suspensorial articulation and around their longitudinal axis, resulting in an extended scraping movement and thereby covering a large surface area. The lower jaws also show a left-right asymmetry in their movements during scraping. Thus, our results suggest that the extreme morphological specializations of the jaws in loricariid catfishes are linked to an increased mobility and functional versatility, allowing these animals to efficiently scrape algae from substrates with irregular surfaces.

  7. Multiplanar CT reconstruction of the jaw: a new way for implant diagnostics

    NASA Astrophysics Data System (ADS)

    Gursky, S.; Wittek, Werner; Wilke, Walter; Schulz, H.; Lieberenz, S.

    1990-11-01

    For preoperative planning of dental implantations pictorial representations are required that permit to evaluate the size of teeth holes, size and structure of jaw bones, position of the mandibular channel and of the alveolar nerve. Since normal transaxial. CT images do not meet these requirements special secondary reconstructions adapted to jaw anatomy are necessary: -panoramic secondary cuts The cut line follows jaw curvature and represents a similar view as orthopantomographic pictures. (see Fig.1) -oblique secondary cuts That are plane cuts perpendicular to the panoramic cut line. (see Fig.2)

  8. Updates on bisphosphonates and potential pathobiology of bisphosphonate-induced jaw osteonecrosis.

    PubMed

    Sarin, J; DeRossi, S S; Akintoye, S O

    2008-04-01

    Osteonecrosis of the jaws is a major complication associated with long-term use of bisphosphonates. While osteonecrosis can arise from other precipitating conditions, bisphosphonate-induced jaw osteonecrosis (BJON) is highly associated with long-term administration of pamidronate (Aredia) and zoledronic acid (Zometa), which are two intravenous bisphosphonate formulations. The underlying pathogenesis of BJON and its site-specific presentation still remain to be fully elucidated. This review will discuss clinically available bisphosphonates, current opinions, pathogenesis, and management guidelines for bisphosphonate-induced jaw osteonecrosis.

  9. Valuable Radiographic Tool for Odontogenic Jaw Keratocyst Diagnosis and Surgical Planning

    PubMed Central

    Lai, R-F; Li, Z-J

    2014-01-01

    Objective: To investigate the clinical use of cone beam computed tomography in the diagnosis of patients with odontogenic jaw keratocyst and to guide computer-aided surgical treatment planning. Methods: Imaging, image processing, and visualization technologies were used to produce clear diagnosis, provide proper treatment, and formulate favourable prognosis. Cone beam computed tomography was used to collect medical information including site, extent, shape, and other characteristic features of a patient with large odontogenic jaw keratocyst. Results: The imaging technique produced excellent results in imaging, image processing and threedimensional (3D) visualization. Conclusion: The 3D digital reconstruction model of the odontogenic jaw keratocyst was shown intuitively. PMID:25429483

  10. The Role of Antiangiogenic Therapy in the Development of Osteonecrosis of the Jaw.

    PubMed

    Fantasia, John E

    2015-11-01

    There is an increasing use of established and newer medications that have antiangiogenic properties. Inhibition of angiogenesis likely has either a primary or secondary role in the development of osteonecrosis of the jaw (ONJ). These medications are being used in the treatment of various cancers and in the treatment of several non-oncologic conditions. Antiangiogenic medications when used in combination with antiresorptive medications, such as nitrogen-containing bisphosphonates or denosumab, seem to increase the likelihood of osteonecrosis of the jaw. This review highlights the role of inhibitors of angiogenesis and their role in the development of osteonecrosis of the jaws.

  11. Osteonecrosis of the jaw and bisphosphonates in cancer: a narrative review.

    PubMed

    Migliorati, Cesar A; Epstein, Joel B; Abt, Elliot; Berenson, James R

    2011-01-01

    Bisphosphonate-associated osteonecrosis (BON) is a complication that almost exclusively affects the jaw bones. The clinical presentation of BON often mimics that of other conditions, such as routine dental disease, osteoradionecrosis or avascular necrosis; therefore, diagnosis can be difficult. As this complication has only been recognized within the past 10 years, management strategies for patients with BON are poorly defined. Physicians must choose between continuing the bisphosphonate therapy (to reduce the risk of skeletal complications in patients with metastatic bone disease or osteoporosis) and discontinuing the drug (to possibly improve the odds for tissue healing). A conservative or aggressive management strategy must be chosen with limited evidence that the outcome of either strategy will be successful. BON is most prevalent in patients with cancer using intravenous nitrogen-containing bisphosphonates. The pathobiology of this complication is not fully understood and the diagnosis relies on the clinical manifestations of the condition. Future research should focus on the pathobiological mechanisms involved in the development of BON, which could help explain why this complication affects only a small number of those who use bisphosphonates, and also suggest strategies for prevention and management.

  12. Surgical resection and vascularized bone reconstruction in advanced stage medication-related osteonecrosis of the jaw.

    PubMed

    Caldroney, S; Ghazali, N; Dyalram, D; Lubek, J E

    2017-07-01

    A retrospective review of all patients with stage 3 medication-related osteonecrosis of the jaw (MRONJ), treated by surgical resection and immediate vascularized bone reconstruction at a tertiary care medical center, was performed. Eleven patients were included, seven female and four male; their mean age was 65.8 years (range 56-73 years). Mean follow-up was 25 months. Ten patients had received intravenous bisphosphonates. The most common pathology was breast cancer (4/11). Pain (n=8) and pathological fracture (n=7) were the most common presenting symptoms. Microvascular free flaps consisted of seven fibula osteocutaneous flaps and four scapula osteocutaneous free flaps. All patients reported resolution of symptoms, with complete bone union identified radiographically (100%). Complications occurred in three patients (27%). One patient required removal of hardware at 8 months postoperative. Dental implant rehabilitation was completed in two patients. Ten patients are tolerating an oral diet. Ten patients are alive without evidence of MRONJ at any of the surgical sites. One patient died 28 months after surgery from progression of metastatic disease. Advanced MRONJ can be successfully treated in patients using vascularized tissue transfer, including those patients with significant peripheral vascular disease. Dental rehabilitation is a viable option for advanced MRONJ patients treated by vascularized flap reconstruction. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  13. Conservative Surgical Management of Stage I Bisphosphonate-Related Osteonecrosis of the Jaw

    PubMed Central

    Vescovi, Paolo; Merigo, Elisabetta; Meleti, Marco; Manfredi, Maddalena; Nammour, Samir; Mergoni, Giovanni; Bagan, Jose V.

    2014-01-01

    Purpose. To report the efficacy of conservative surgical treatment for stage I bisphosphonate-related osteonecrosis of the jaw (BRONJ). Materials and Methods. This study reports the clinical outcomes of 63 patients treated for BRONJ stage I (according to Ruggiero's staging system) at the Oral Pathology and Laser-Assisted Surgery Unit of the University of Parma between January 2004 and January 2011. Surgical interventions were performed, under local analgesia, in patients unresponsive for a period of six months to noninvasive treatments such as cycles of local or systemic antibacterial therapy combined or not to low level laser therapy, ozone therapy, or Hyperbaric Oxygen Therapy. All interventions were performed after the consultation of oncologist or physician. Results. In our experience, conservative surgical treatment is associated with the highest number of BRONJ healed sites in stage I disease. Complete healing was observed in 92.6% of sites surgically treated. Conclusions. This study confirms that treatment of patients affected by minimal bone exposition, (stage I of BRONJ), through conservative surgical strategies, possibly with laser, may result in a high control of the disease in the long term. PMID:24648841

  14. Treatment of osteonecrosis of the jaw related to bisphosphonates and other antiresorptive agents

    PubMed Central

    Oñate-Sánchez, Ricardo-Elías

    2016-01-01

    Background The clinical management of medication-related osteonecrosis of the jaw (MRONJ) in patients treated with bisphosphonates and other antiresorptive agents is subject to controversy. The American Association of Oral and Maxillofacial Surgeons (AAOMS) has developed guidelines for the correct management of the disorder which are revised and updated by a panel of experts. Material and Methods The present systematic review analyzes the different treatments currently used to treat this clinical condition, based on the PRISMA® (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement published in 2009. An electronic Medline search was made of the PubMed database, covering the period 2006-2014. The last search date was 31 December 2014. Results A total of 29 articles were selected from the initial search according to the different drugs implicated in the appearance of osteonecrosis; the treatment modality used according to the stage of the disease; and the recorded success rate. Conclusions It is currently still recommended that the management of MRONJ should be decided according to the stage of the disease – conservative treatment being preferred in early stages without symptoms, while surgical management is preferred in the case of bone exposure with symptoms. Key words:Osteonecrosis, medication, bisphosphonates, treatments, review PMID:27475683

  15. Intravenous bisphosphonate-related osteonecrosis of the jaw: bone scintigraphy as an early indicator.

    PubMed

    O'Ryan, Felice S; Khoury, Sam; Liao, Wendy; Han, Myo M; Hui, Rita L; Baer, David; Martin, Daniel; Liberty, Donald; Lo, Joan C

    2009-07-01

    Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is recognized as a serious complication among patients receiving bisphosphonate therapy. However, methods for early detection and identification of patients at risk for osteonecrosis of the jaw (ONJ) need further investigation. The purpose of this study was to characterize BRONJ among patients receiving intravenous bisphosphonates and to examine bone scintigraphy findings that preceded manifestation of frank ONJ. We identified all known cases of BRONJ (defined according to 2006 American Association of Oral and Maxillofacial Surgeons criteria) diagnosed between January 2004 and September 2008 among patients who received intravenous bisphosphonate therapy (IVBP). The medical records were abstracted, and the clinical and radiographic features of BRONJ and relevant comorbidities were characterized. Technetium Tc 99 bone scintigrams were systematically reviewed among the subset of patients who received these imaging studies for oncologic care and imaging findings were correlated with the temporal development of ONJ. We identified 59 cases of intravenous BRONJ (median age, 61.4 +/- 10.7 years; 57.6% female), of whom 44.1% had breast cancer, 33.9% had multiple myeloma, and the remainder had metastatic prostate cancer (15.3%) or other cancers (6.8%). One third (32.2%) of the cohort was diabetic. In addition to IVBP, the vast majority (86.4%) had also received prior systemic glucocorticoid therapy. The median cumulative number of IVBP doses was 25 (interquartile range, 16-39) at the time of BRONJ diagnosis. Half of the patients had prior invasive dental procedures; ONJ developed spontaneously in 27.1%, and in the remainder ONJ developed in the setting of periodontal disease (10.1%) or local trauma (8.4%). Most patients presented with painful stage 2 disease involving the mandible (75%), and Actinomyces was present in more than 77% of available histologic specimens. During the median follow-up of 1.5 years, 15 patients

  16. Clinical comparison of patients with osteonecrosis of the jaws, with and without a history of bisphosphonates administration.

    PubMed

    Kos, M; Brusco, D; Kuebler, J; Engelke, W

    2010-11-01

    This retrospective study aimed to evaluate the role of bisphosphonates in jaw osteomyelitis. 29 patients were included: 18 had been treated with bisphosphonates (12 with multiple myelomas, 3 with breast carcinomas, 2 with prostate carcinomas, and 1 with osteoporosis). Of 11 control patients, 2 had breast carcinomas, 2 had bronchial carcinomas, and 7 had no cancer. Descriptive and statistical evaluations were conducted to investigate the influence of chemotherapy, corticosteroids, stem cell transplantation, and bisphosphonates on the development and clinical picture of osteomyelitis. Both groups had similar disease histories, clinical pictures, treatment methods, and outcome. Wound dehiscence frequencies were also similar (Mann-Whitney rank sum test 1.66±1.5 vs. 1.45±2.0 p=0.393). Chemotherapy, steroid therapy, stem cell transplantation, or bisphosphonate administration did not correlate with the clinical picture. Neither the duration of therapy nor the type of bisphosphonate influenced the clinical picture (negative Fisher's tests). The bisphosphonate group showed a characteristic settlement of Actinomyces in the exposed bone (positive Fisher's test, p=0.021). These results suggested that osteomyelitis developed as a consequence of the simultaneous, cumulative action of many factors. Bisphosphonates played a role comparable to other predisposing features. Coating the jaws with bisphosphonates could promote the settlement of Actinomyces. Copyright © 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  17. Jaw bone tissue state of stress and deformation investigation in process implantation

    NASA Astrophysics Data System (ADS)

    Sukharev, Michail P.; Tchurajev, Alexandr L.

    1992-06-01

    The aim of this investigation was studying the regularities of the strain distributions around in- bone implants of various shapes: cone, cylinder, tube, and blade-vent. Secondly, it was to study the force parameters of the cortical and porous bone substance when blade-vent implants of various size which are the distal supports of the bridge-shaped dentures are introduced into the planting bed. By means of the histological radiology method we carried out a study of the upper and lower jaws architectures on the basis of jaw segments investigation. A study was carried out by means of holographic interferometry of compression and tension areas distribution in the skull bones, the upper and lower jaws and temporo mandibular joint area under load. A laser holographic set-up used to obtain interference patterns covering strained and deformed jaws containing introduced implants consisted of a He-Ne laser, mirrors, lenses, a hologram, a VC, a TV monitor, and loading device.

  18. Bisphosphonate-associated osteomyelitis of the jaw: guidelines for practicing clinicians.

    PubMed

    Wimalawansa, Sunil J

    2008-12-01

    To evaluate the literature and discuss the risk factors, mechanisms, pathophysiologic aspects, and recommended management of bisphosphonate-associated osteomyelitis of the jaw (BAOMJ). More than 350 published articles, case reports mentioning BAOMJ, and independent histology slides from BAOMJ lesions were reviewed critically. The most pertinent publications are cited and discussed. The incidence of BAOMJ increases after extraction of teeth, dentoalveolar surgical procedures, or recent oral trauma leading to exposed maxillary or mandibular bone. Contributory factors include poor oral hygiene, oral infections, periodontal disease; recent or ongoing corticosteroid administration or chemotherapy; compromised immune status; diabetes or vascular insufficiency; old age; chronic diseases; and malignancies. On average, 1 of every 100,000 patients treated with bisphosphonates orally for osteoporosis or Paget disease of bone may develop BAOMJ-like lesions. Patients with cancer often receive bisphosphonate doses 10 times or higher, and also more frequently, than those used in patients with osteoporosis or Paget disease of bone. Therefore, greater frequency of administration of bisphosphonates, higher dosages, and prolonged use (that is, for more than 2 years) are likely to be factors triggering BAOMJ. The association of bisphosphonate therapy with BAOMJ is rare in noncancer patients and is likely to be a class effect that may occur with use of any bisphosphonate. Whether patients with cancer require such a high frequency of intravenously administered bisphosphonates needs to be investigated. Following established guidelines can decrease the risks of BAOMJ in vulnerable patients. Rather than necrotic bone, current evidence supports an infectious and perhaps immunologic underlying cause for BAOMJ. The estimated incidence of BAOMJ among noncancer patients receiving bisphosphonates is about 0.001%, whereas among patients with cancer receiving intravenous bisphosphonate therapy the

  19. Computed tomography and partial coronoidectomy for open-mouth jaw locking in two cats.

    PubMed

    Soukup, Jason W; Snyder, Christopher J; Gengler, William R

    2009-01-01

    Open-mouth jaw locking in the cat has traditionally been minimally evaluated with diagnostic imaging. Multiple methods have been described for surgical management of this problem. This report describes the use of computed tomography to diagnose open-mouth jaw locking in 2 cats secondary to ventrolateral displacement of the coronoid process in relation to the zygomatic arch. In these 2 cases, a previously unreported surgical approach whereby the coronoid was not reduced before partial coronoidectomy was used with successful outcomes.

  20. Jaw expansive lesions: population incidence and CT dentalscan role

    PubMed Central

    FIASCHETTI, V.; FANUCCI, E.; RASCIONI, M.; OTTRIA, L.; BARLATTANI, A.; SIMONETTI, G.

    2011-01-01

    SUMMARY Aim The aim of the study is to evaluate the incidence of different expansive lesions and the advantages of the clinical employment of Dentalscan to study bones lesions and to establish a common diagnostic path. Materials and methods Since January 2005 to November 2009, 3200 patients, not selected for sex or age, have undergone a CT “Dentalscan” in the department of Diagnostic Imaging, Tor Vergata University Hospital (PTV), a suspect bone pathology was found in 704 of them through the XR-orthopantomograpy (OPT). CT images were obtained with General Electric CT Light Speed multislice. Images were saved in the Advantage Workstation (GE) supported by the “Dentascan” dedicated software and by the 3D software (3D SSD). The protocol was : Slice thickness 1,25 mm, gap 0, matrix 512 × 512, 140 KV and 70 mA. All the lesions were also studied with the dedicated three-dimensional reconstructor 3D SSD. Biopsy for diagnosis was performed on all the lesions, except one (false positive with digital OPT). The technique sensitivity was assessed for two important classes: benign and malignant lesions. Results Through CT Dentascan a detailed evaluation of the jaws lesions and their extension was obtained. 656 patients (93.1 %) out of 704 examined for a suspicious lesion on the orthopantomography had a benign lesion: (127 follicular cysts (18.2 %), 181 radicular cysts (25.1%), 93 non odontogenic cysts (13.2%), 29 fibroma (4.2%), 198 odontomes (28.2%), 24 ameloblastoma (3.6%), 4 brown tumors (0.7%), 47 (6.9%) had malignant lesions: (12 carcinoma (1.7%), 29 metastasis (4.3%), 6 sarcoma (0.8%), 1 Dentascan CT resulted to be negative (1 false positive of digital OPT). The sensitivity of the technique for both groups was 99% for benign lesions and 98% for malign lesions. Conclusions CT Dentascan characteristics suggest to consider these techniques as the gold standard for the evaluation of jaw expansive lesions and the support of surgical planning. PMID:23285385

  1. [De novo (type 3) primary intraosseous carcinoma of the jaws].

    PubMed

    Ray, A C; Foletti, J M; Graillon, N; Guyot, L; Chossegros, C

    2016-12-01

    Primary intraosseous carcinoma (PIOC) of the jaws is a rare epidermoid carcinoma from epithelial origin and initially strictly localized within the bone. Histologically, type 3 PIOC (PIOC3) is a de novo primary intraosseous carcinoma. Because of the rarity of this illness, we propose an analysis of a personal case and a revue of the literature. Two search engines (Pubmed(®), Sciencedirect(®)) were questioned over the period 1976-February 2016 by using following keywords carcinoma, intraosseous, jaws, squamous cell carcinoma. Articles reporting proven PIOC3 and mentioning a precise treatment were selected. Thirty articles concerning 54 patients (sex ratio: 2.4; mean age: 56.8; extreme: 24-78) met the inclusion criterions. The most common symptoms were swelling (53%), pain (44.9%) and infra-alveolar nerve paresthesia (30.6%). The time to diagnosis was 13 weeks. Classification of Zwetyenga et al. showed more than 80% of T2 and T3 stages. The lesions were predominantly mandibular (85.2%) and posterior. Less than a third of patients had lymph node and 10% had distant metastasis. Treatment consisted mostly in a combination of surgery and radiotherapy. With a mean follow-up of 74.8 months, 70.8% were in remission with no evidence of recurrence. We report the case of a 58-year-old patient, with no medical history, complaining since several months about periodontitis with teeth mobility in the right mandibular area. The panoramic X-ray showed a bone lysis at the place of tooth No. 46. In the absence of alveolar healing after extraction and antibiotherapy, a biopsy was made that diagnosed a differentiated keratinizing squamous cell carcinoma. CT scan and MRI showed a mandibular cortical bone loss with involvement of adjacent structures and lymphadenopathy in the ipsilateral IB area. The patient was treated with a combination of chemotherapy and surgery. Postoperative chemo- and radiotherapy is still going on. The PIOC3 is a rare tumor, mainly arising in males around 50

  2. Role of stag beetle jaw bending and torsion in grip on rivals

    PubMed Central

    Goyens, Jana; Dirckx, Joris; Piessen, Maxim; Aerts, Peter

    2016-01-01

    In aggressive battles, the extremely large male stag beetle jaws have to withstand strongly elevated bite forces. We found several adaptations of the male Cyclommatus metallifer jaw morphology for enhanced robustness that conspecific females lack. As a result, males improve their grip on opponents and they maintain their safety factor (5.2–7.2) at the same level as that of females (6.8), despite their strongly elevated bite muscle force (3.9 times stronger). Males have a higher second moment of area and torsion constant than females, owing to an enhanced cross-sectional area and shape. These parameters also increase faster with increasing bending moment towards the jaw base in males than in females. Male jaws are more bending resistant against the bite reaction force than against perpendicular forces (which remain lower in battles). Because of the triangular cross section of the male jaw base, it twists more easily than it bends. This torsional flexibility creates a safety system against overload that, at the same time, secures a firm grip on rivals. We found no structural mechanical function of the large teeth halfway along the male jaws. Therefore, it appears that the main purpose of these teeth is a further improvement of grip on rivals. PMID:26763329

  3. Modification of cortically evoked rhythmic jaw movements by reflex deglutition in rabbits.

    PubMed

    Sumi, T

    1977-01-01

    In rabbits, lightly anesthetized with ether, tetanic stimulation of the superior laryngeal nerve (SLN) displaced the jaw toward opening and reduced the amplitude of cortically evoked rhythmic jaw movements. With increased intensity of stimulus, the effects became remarkable and the opened jaw movement ultimately ceased. Reflex swallowing in reaction to weak electrical stimuli of SLN or to a small amount of water squirted into the oropharynx yielded a brief and instantaneous cessation of rhythmic jaw movements with the jaw open. Strong electrical stimuli to the nerve or a squirt of relatively large amount of water into the oropharynx prolonged the duration of both swallowing and the cessation of rhythmic jaw movements for about 1.0 sec. Reflex swallowing yielded a burst of activity for about 300 msec in the mylohyoideus and silence for a longer period in the masseter. Spontaneous activity of the masseter was moderately decreased during the nerve stimulation and, when swallowing occurred, this decrease became prominent for a short period.

  4. Postnatal development of fiber type composition in rabbit jaw and leg muscles.

    PubMed

    Korfage, J A M; Helmers, R; Matignon, M de Goüyon; van Wessel, T; Langenbach, G E J; van Eijden, T M G J

    2009-01-01

    We examined the difference in fiber type composition and cross-sectional areas during postnatal development in male rabbit jaw muscles and compared these with changes in leg muscles. The myosin heavy chain (MyHC) content of the fibers was determined by immunohistochemistry. No fiber type difference was found between the jaw muscles in 20-week-old rabbits. However, the way this adult fiber type composition was reached differed between the muscles. The deep temporalis, medial pterygoid, and superficial masseter displayed an increase in alpha fibers during early and a decrease during late postnatal development. Other jaw muscles displayed an increase in alpha fibers during early development only. In contrast, alpha fibers were not found in the soleus, in which fiber type changes were completed at week 4. The gastrocnemius muscle did not change its fiber type composition. Initially, fibers in jaw-opening muscles had larger cross-sectional areas than in other muscles, but they increased less during development. Although there were no large differences in the fiber type composition of muscles in young adult rabbits, large differences were found in the jaw muscles, but not in the leg muscles, during development. In part, these developmental changes in fiber percentages within the jaw muscles can be explained by functional modifications in this muscle group. In the present study, the deep temporalis, medial pterygoid, and superficial masseter showed the most dramatic percent changes in fibers during postnatal development. (c) 2008 S. Karger AG, Basel.

  5. Does eccentric-exercise-induced jaw muscle soreness influence brainstem reflexes?

    PubMed

    Torisu, Tetsurou; Wang, Kelun; Svensson, Peter; Laat, Antoon De; Yamabe, Yoshihisa; Murata, Hiroshi; Arendt-Nielsen, Lars

    2008-12-01

    To investigate the effects of soreness evoked by eccentric jaw exercises on two types of brainstem reflexes: the short-latency stretch reflex and the longer-latency exteroceptive suppression (ES), and to test for possible relationships between magnitude of soreness and reflex responses. The brainstem reflexes of jaw-closing muscles were recorded before (Baseline), immediately after (Post-task), and 1 day after (1-day-after) a 30-min eccentric exercise in 15 healthy men. All subjects participated in a control session without exercise. Soreness sensations at rest and during maximum biting were significantly elevated until 1-day-after the eccentric exercise (P<0.014). The ES responses tended to be increased (more inhibition) at Post-task and 1-day-after. There was a significant correlation between the ES response and the soreness sensation during maximum biting (P<0.04). The jaw-stretch reflex did not show significant change after the eccentric exercise. Muscle soreness associated with eccentric jaw exercises has a differential impact on the jaw-stretch reflex and the ES response. Experimentally induced acute muscle pain has previously been shown to influence both the ES and the jaw-stretch reflex, thus, different types of muscle pain and symptoms can be speculated to have different effects on a variety of brainstem reflexes.

  6. Risk of Jaw Osteonecrosis After Intravenous Bisphosphonates in Cancer Patients and Patients Without Cancer.

    PubMed

    Goodwin, James S; Zhou, Jie; Kuo, Yong-Fang; Baillargeon, Jacques

    2017-01-01

    To compare the risk of jaw osteonecrosis after intravenous (IV) bisphosphonate administered to patients with cancer vs patients without cancer. We conducted a retrospective cohort study of a 5% national sample of Medicare patients administered IV bisphosphonate from January 1, 2008, through December 31, 2013, for cancer vs noncancer indications. Probable jaw osteonecrosis was estimated with an algorithm including diagnoses, surgical procedures, and imaging studies. A non-IV bisphosphonate comparison group included patients prescribed an oral bisphosphonate for 30 days or less. During follow-up, 40 (0.42%) out of 9482 patients with cancer developed probable jaw osteonecrosis compared with 8 (0.05%) out of 16,046 patients without cancer. In a Cox multivariable survival analysis controlling for patient characteristics and number of IV zoledronic infusions, patients without cancer had a hazard ratio of 0.17 (95% CI, 0.06-0.46) for developing jaw osteonecrosis compared with those with cancer. The lower rate of jaw osteonecrosis in patients without cancer was also confirmed in a number of sensitivity analyses. The low rate of jaw osteonecrosis in patients with osteoporosis who receive IV bisphosphonate should be weighed against the benefit of those agents in preventing hip and other fractures. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  7. Vowel effect on glottal parameters and the magnitude of jaw opening.

    PubMed

    Lim, Marilyn; Lin, Emily; Bones, Philip

    2006-03-01

    This study investigated the relationship among the magnitude of jaw opening, intrinsic fundamental frequency (F0), and glottal parameters in natural speech. Acoustic, jaw opening, and electroglottographic (EGG) signals were simultaneously recorded. The subjects were 10 healthy men with New Zealand English as their native language. Subjects were asked to repeat a standard nonemphasized sentence in which one of the target vowels (/a/, /e/, /i/, /o/, and /u/) was embedded in various contexts. The glottal parameters F0, open quotient (OQ), and speed quotient (SQ) were measured from the EGG signal. Results of a series of one-way repeated-measures analyses of variance (ANOVA) showed a significant vowel effect on the magnitude of jaw opening [F(4, 24) = 25.512, P < .001], F0 [F(4, 28) = 45.415, P < .001] and speed quotient [F(4, 28) = 5.233, P = .003], but not on the open quotient [F(4, 28) = 0.501, P = .735]. The magnitude of jaw opening was found to be inversely related with F0 (r = -0.624, n = 25, P = .0009). These findings showed that the magnitude of jaw opening was related to F0 and that jaw opening might be a control signal for simulation of long-term F0 variation to achieve a higher degree of naturalness in artificial voice.

  8. New therapeutic protocol in the treatment of avascular necrosis of the jaws.

    PubMed

    Agrillo, Alessandro; Petrucci, Maria Teresa; Tedaldi, Massimiliano; Mustazza, Maria Cristina; Marino, Simone Maria Faustino; Gallucci, Cristiano; Iannetti, Giorgio

    2006-11-01

    Osteonecrosis of the jaws is being increasingly reported in patients with bone metastasis from a variety of solid tumors and disseminated multiple myeloma receiving intravenous bisphosphonates. Agreement exists that these drugs can initiate vascular endothelial cell damage and accelerate disturbances in the microcirculation of the jaws, possibly resulting in thrombosis of nutrient-end arteries. The role of bisphosphonates in cancer patients with previously treated jaws has yet to be elucidated. The signs and symptoms that may occur before the appearance of evident osteonecrosis include changes in the health of periodontal tissues, nonhealing mucosal ulcers, loose teeth and unexplained soft tissue infection. A series of 30 periodontally involved patients showing osteonecrosis of the jaws that appeared following the intravenous use of bisphosphonates is reported. Clinical management of the avascular necrosis of the jaws in patients treated with bisphosphonates presents several problems. An analysis of the international medical literature shows that surgical treatment of the necrotic jaws in patients treated with bisphosphonates has proven to be ineffective in stopping the pathological process. The use of hyperbaric oxygen and antibiotics are not effective, either. The authors have developed a new protocol for the management of these lesions. Compared with other therapeutic choices, this protocol has introduced the use of ozone therapy as therapeutic support.

  9. Role of stag beetle jaw bending and torsion in grip on rivals.

    PubMed

    Goyens, Jana; Dirckx, Joris; Piessen, Maxim; Aerts, Peter

    2016-01-01

    In aggressive battles, the extremely large male stag beetle jaws have to withstand strongly elevated bite forces. We found several adaptations of the male Cyclommatus metallifer jaw morphology for enhanced robustness that conspecific females lack. As a result, males improve their grip on opponents and they maintain their safety factor (5.2-7.2) at the same level as that of females (6.8), despite their strongly elevated bite muscle force (3.9 times stronger). Males have a higher second moment of area and torsion constant than females, owing to an enhanced cross-sectional area and shape. These parameters also increase faster with increasing bending moment towards the jaw base in males than in females. Male jaws are more bending resistant against the bite reaction force than against perpendicular forces (which remain lower in battles). Because of the triangular cross section of the male jaw base, it twists more easily than it bends. This torsional flexibility creates a safety system against overload that, at the same time, secures a firm grip on rivals. We found no structural mechanical function of the large teeth halfway along the male jaws. Therefore, it appears that the main purpose of these teeth is a further improvement of grip on rivals.

  10. Comparative jaw muscle anatomy in kangaroos, wallabies, and rat-kangaroos (marsupialia: macropodoidea).

    PubMed

    Warburton, Natalie Marina

    2009-06-01

    The jaw muscles were studied in seven genera of macropodoid marsupials with diets ranging from mainly fungi in Potorous to grass in Macropus. Relative size, attachments, and lamination within the jaw adductor muscles varied between macropodoid species. Among macropodine species, the jaw adductor muscle proportions vary with feeding type. The relative mass of the masseter is roughly consistent, but grazers and mixed-feeders (Macropus and Lagostrophus) had relatively larger medial pterygoids and smaller temporalis muscles than the browsers (Dendrolagus, Dorcopsulus, and Setonix). Grazing macropods show similar jaw muscle proportions to "ungulate-grinding" type placental mammals. The internal architecture of the jaw muscles also varies between grazing and browsing macropods, most significantly, the anatomy of the medial pterygoid muscle. Potoroines have distinctly different jaw muscle proportions to macropodines. The masseter muscle group, in particular, the superficial masseter is enlarged, while the temporalis group is relatively reduced. Lagostrophus fasciatus is anatomically distinct from other macropods with respect to its masticatory muscle anatomy, including enlarged superficial medial pterygoid and deep temporalis muscles, an anteriorly inflected masseteric process, and the shape of the mandibular condyle. The enlarged triangular pterygoid process of the sphenoid bone, in particular, is distinctive of Lagsotrophus. (c) 2009 Wiley-Liss, Inc.

  11. Evolution of Muscle Activity Patterns Driving Motions of the Jaw and Hyoid during Chewing in Gnathostomes

    PubMed Central

    Konow, Nicolai; Herrel, Anthony; Ross, Callum F.; Williams, Susan H.; German, Rebecca Z.; Sanford, Christopher P. J.; Gintof, Chris

    2011-01-01

    Although chewing has been suggested to be a basal gnathostome trait retained in most major vertebrate lineages, it has not been studied broadly and comparatively across vertebrates. To redress this imbalance, we recorded EMG from muscles powering anteroposterior movement of the hyoid, and dorsoventral movement of the mandibular jaw during chewing. We compared muscle activity patterns (MAP) during chewing in jawed vertebrate taxa belonging to unrelated groups of basal bony fishes and artiodactyl mammals. Our aim was to outline the evolution of coordination in MAP. Comparisons of activity in muscles of the jaw and hyoid that power chewing in closely related artiodactyls using cross-correlation analyses identified reorganizations of jaw and hyoid MAP between herbivores and omnivores. EMG data from basal bony fishes revealed a tighter coordination of jaw and hyoid MAP during chewing than seen in artiodactyls. Across this broad phylogenetic range, there have been major structural reorganizations, including a reduction of the bony hyoid suspension, which is robust in fishes, to the acquisition in a mammalian ancestor of a muscle sling suspending the hyoid. These changes appear to be reflected in a shift in chewing MAP that occurred in an unidentified anamniote stem-lineage. This shift matches observations that, when compared with fishes, the pattern of hyoid motion in tetrapods is reversed and also time-shifted relative to the pattern of jaw movement. PMID:21705368

  12. Evolution of muscle activity patterns driving motions of the jaw and hyoid during chewing in Gnathostomes.

    PubMed

    Konow, Nicolai; Herrel, Anthony; Ross, Callum F; Williams, Susan H; German, Rebecca Z; Sanford, Christopher P J; Gintof, Chris

    2011-08-01

    Although chewing has been suggested to be a basal gnathostome trait retained in most major vertebrate lineages, it has not been studied broadly and comparatively across vertebrates. To redress this imbalance, we recorded EMG from muscles powering anteroposterior movement of the hyoid, and dorsoventral movement of the mandibular jaw during chewing. We compared muscle activity patterns (MAP) during chewing in jawed vertebrate taxa belonging to unrelated groups of basal bony fishes and artiodactyl mammals. Our aim was to outline the evolution of coordination in MAP. Comparisons of activity in muscles of the jaw and hyoid that power chewing in closely related artiodactyls using cross-correlation analyses identified reorganizations of jaw and hyoid MAP between herbivores and omnivores. EMG data from basal bony fishes revealed a tighter coordination of jaw and hyoid MAP during chewing than seen in artiodactyls. Across this broad phylogenetic range, there have been major structural reorganizations, including a reduction of the bony hyoid suspension, which is robust in fishes, to the acquisition in a mammalian ancestor of a muscle sling suspending the hyoid. These changes appear to be reflected in a shift in chewing MAP that occurred in an unidentified anamniote stem-lineage. This shift matches observations that, when compared with fishes, the pattern of hyoid motion in tetrapods is reversed and also time-shifted relative to the pattern of jaw movement.

  13. Evidence for the prepattern/cooption model of vertebrate jaw evolution.

    PubMed

    Cerny, Robert; Cattell, Maria; Sauka-Spengler, Tatjana; Bronner-Fraser, Marianne; Yu, Feiqiao; Medeiros, Daniel Meulemans

    2010-10-05

    The appearance of jaws was a turning point in vertebrate evolution because it allowed primitive vertebrates to capture and process large, motile prey. The vertebrate jaw consists of separate dorsal and ventral skeletal elements connected by a joint. How this structure evolved from the unjointed gill bar of a jawless ancestor is an unresolved question in vertebrate evolution. To understand the developmental bases of this evolutionary transition, we examined the expression of 12 genes involved in vertebrate pharyngeal patterning in the modern jawless fish lamprey. We find nested expression of Dlx genes, as well as combinatorial expression of Msx, Hand and Gsc genes along the dorso-ventral (DV) axis of the lamprey pharynx, indicating gnathostome-type pharyngeal patterning evolved before the appearance of the jaw. In addition, we find that Bapx and Gdf5/6/7, key regulators of joint formation in gnathostomes, are not expressed in the lamprey first arch, whereas Barx, which is absent from the intermediate first arch in gnathostomes, marks this domain in lamprey. Taken together, these data support a new scenario for jaw evolution in which incorporation of Bapx and Gdf5/6/7 into a preexisting DV patterning program drove the evolution of the jaw by altering the identity of intermediate first-arch chondrocytes. We present this "Pre-pattern/Cooption" model as an alternative to current models linking the evolution of the jaw to the de novo appearance of sophisticated pharyngeal DV patterning.

  14. Clinical experience with spiramycin in bisphosphonate-associated osteonecrosis of the jaw.

    PubMed

    Gasparini, G; Saponaro, G; Di Nardo, F; Moro, A; Boniello, R; Cervelli, D; Marianetti, T M; Palazzoni, G; Pelo, S

    2010-01-01

    Bisphosphonate-related osteonecrosis of the jaw (BRONJ) consists of an exposure of the jaw bone that persists for over 8 weeks in patients with positive history for bisphosphonates. Symptomatology is characterized by dull and ceaseless pain, and in advanced stages, the exposure of necrotic bone is evident, which is frequently associated with purulent secretions and faetor oris. Despite many different studies on BRONJ, there are no general guidelines to treat this disease. In this work, the authors present their experience in BRONJ conservative therapy with spiramycin by comparing the results achieved with amoxicillin and clavulanic acid. From January 1, 2008 to June 30, 2008, our department received 25 patients who were affected by osteonecrosis secondary to bisphosphonates. Thirteen had taken bisphosphonates for osteoporosis and 12 for malignancies. We divided the 25 patients into two groups: those who had not received any treatment and those who had received treatment. The first group of 13 patients had been treated only with spiramycin (S). The results from this group were only evaluated to test the efficacy of spiramycin and were not considered in the study. The second group of 12 patients had not undergone any previous treatment. This group was further divided in two groups of 6 patients each; one group was treated with spiramycin and the other with amoxicillin and clavulanic acid (ACA). The following criteria were used to evaluate the results of the study: pain, sensibility deficits, purulent secretion and bone exposure. All group results were evaluated according to the criteria chosen, and positive results were achieved in both groups S and ACA, such as reduction or disappearance of pain, sensibility deficits and purulent secretion and healing of bone exposition, although spiramycin showed itself to be more effective than the combination of amoxicillin and clavulanic acid. Spiramycin is a macrolide antibiotic with a wide spectrum of activity against

  15. Osteonecrosis of the jaws in 194 patients who have undergone intravenous bisphosphonate therapy in Spain

    PubMed Central

    Pérez-Sayáns, Mario; Suárez-Peñaranda, José-Manuel; Gándara-Rey, José-Manuel; García-García, Abel

    2015-01-01

    Background Osteonecrosis of the jaw (ONJ) is a destructive bone process in patients undergoing bisphosphonate therapy and it is modulated by local and systemic factors. The purpose of this article is to determine the prevalence of ONJ in patients who have undergone intravenous bisphosphonate therapy, and relate the risk factors described to establish a protocol to reduce the risk of developing ONJ. Material and Methods We performed a retrospective study on 194 patients treated with IV bisphosponates, analyzing clinical and pathological variables. Results The prevalence of ONJ was 12.9 %. The most remarkable complication was pain, which was reported by 80% of patients. The average age of the patients undergoing bisphosphonate therapy was 68.91 years. Most of non-diabetic patients did not develop ONJ (92.3%) (p=0.048). During bisphosphonate therapy, 3.1% of patients underwent extractions in the same percentage in the maxilla and in the mandible; all of which, except for one patient, developed ONJ (p<0.001). In regards to the periodontal state, 94.3% of patients without periodontal problems did not develop ONJ (p=0.001). Almost 50% of the necrosis were located unifocally on the mandible (p<0.001). The number of affected patients and the aggressiveness of the disease increased significantly three years after starting treatment (p<0.001). Conclusions Etiology still is a controversial issue and we should focus on known risk factors, such as the development of surgical procedures in patients undergoing bisphosphonate therapy, especially in patients who have already started their treatment, a group in which ONJ prevalence increases. Moreover, a bad periodontal state in these patients is also an important risk factor, and the control of diabetes reduces it. Due to the above, all patients should be diagnosed and educated in oral hygiene prior to treatment, performing periodical maintenance, to detect possible traumatisms and periodontal infection as soon as possible. Key

  16. An Experimental Investigation of the Lymphatic System of the Teeth and Jaws

    PubMed Central

    MacGregor, Alexander

    1936-01-01

    A review of the literature is given, followed by a consideration of the available methods of demonstrating the lymphatic system in the area of the teeth and jaws. A new method of demonstrating this system by the injection or application of lead acetate intra vitam, is described, and the technique is explained. The method can be employed to reveal macroscopic or microscopic lymph channels in any part of the body, and is especially of value where decalcification of the hard tissues has to be carried out in the preparation of the sections. The various types of experiments which have been performed are described, and the macroscopic and microscopic results dealt with separately. Among the macroscopic results, the lymphatic drainage of various parts the jaws is described, and the large amount of anastomosis and cross anastomosis between the vessels is shown. A comparison of the lymphatic system in this region in the guinea-pig, cat, dog, and monkey is given, and it is demonstrated that the guinea-pig and monkey possess submental and supraclavicular lymph nodes which assist in the drainage of this area in addition to the submaxillary and cervical groups of nodes possessed by the cat and the dog. Among the microscopic results, the way in which the mass makes its way from the gingival tissues through the bone, and is found in the pulp, dentine, and cementum of the tooth, even where no pressure is applied, is described. The communication of the lymphatic vessels of the pulp with those of the periodontal membrane and the path of the mass down the periodontal membrane from the gingival trough, and its entry into the alveolar bone from this situation are demonstrated, and the way in which the mass reaches the pulp, dentine, and cementum of the tooth from the gingival tissues is discussed. The significance of various concentrations of the mass in the tissues, particularly the dentine, is also discussed. Control experiments are described, the conclusions which have been reached

  17. Systematic literature review of bisphosphonates and osteonecrosis of the jaw in patients with osteoporosis.

    PubMed

    Chamizo Carmona, Eugenio; Gallego Flores, Adela; Loza Santamaría, Estíbaliz; Herrero Olea, Aurora; Rosario Lozano, María Piedad

    2013-01-01

    To systematically assess the literature related to the occurrence of osteonecrosis of the jaw (ONJ) using bisphosphonates (BP) in the treatment of osteoporosis (OP). We conducted a systematic literature search in PubMed, EMBASE and the Cochrane Central Register of Controlled Trials up to July 2010, including terms relating to OP, ONJ, and BP (MeSH and free text). We selected meta-analysis, systematic reviews and clinical trials (CT), English or Spanish, including patients > 18 years of both sexes with OP treated with BF (intravenous and oral). Furthermore, studies should evaluate the occurrence of ONJ during treatment with BF. We excluded studies that included patients with cancer or diseases other than OP, animal studies and basic science. The selection of articles both by title and 2 independent reviewers conducted a detailed review of the abstracts. We used the modified Oxford Scale (version 2001) to assess the quality of the included studies. We identified 1422 articles of which we included 18 (8 systematic reviews, 8 CT and 2 meta-analysis). Most studies were of good quality and examined the use of BF in middle-aged women with OP. Frequency of ONJ was low. We found insufficient evidence to affirm that intravenous or oral BF used exclusively for the treatment of OP lead to a significant risk of ONJ (evidence level 2a, grade B recommendation). Copyright © 2012 Elsevier España, S.L. All rights reserved.

  18. Osteonecrosis of jaws related to intravenous bisphosphonates: the experience of a Jordanian teaching hospital.

    PubMed

    Baqain, Zaid H; Sawair, Faleh A; Tamimi, Zaid; Bsoul, Nazzal; Al Edwan, Ghazi; Almasad, Jamal K; Abbadi, Abdalla A

    2010-09-01

    We describe our experience with oncology patients on a frequent dosing schedule of intravenous (i.v.) bisphosphonates at the Jordan University Hospital (JUH). Patients treated by i.v. bisphosphonates in the medical oncology unit at the JUH were examined for bisphosphonate-related osteonecrosis of the jaws (BRONJ). Diagnosis was made according to the guidelines of the American Association of Oral and Maxillofacial Surgeons (AAOMS) original position paper. Of the 41 patients, four developed BRONJ, two in maxilla, one in mandible and one bimaxillary. Patients with BRONJ were older; mean age was 69.3 +/- 3.1 years compared to 62.8 +/- 12.5 years (P = 0.022). Dental co-morbidities were more commonly present in patients with the disease (P = 0.038). Patients who developed BRONJ were on treatment for a longer duration of time; the mean duration of treatment was 23.5 +/- 8.4 months compared to 11.9 +/- 13.4 months (P = 0.10). The results of this case series demonstrated that age and poor oral health status are significant risk factors of BRONJ for oncology patients on long-term frequent dosing schedule of i.v. bisphosphonates.

  19. Osteonecrosis of the jaw in patients with bone metastases treated with bisphosphonates: a retrospective study.

    PubMed

    Ibrahim, Toni; Barbanti, Francesca; Giorgio-Marrano, Gianluca; Mercatali, Laura; Ronconi, Sonia; Vicini, Claudio; Amadori, Dino

    2008-03-01

    Bone metastases are a major cause of morbidity in cancer patients. Treatment includes bisphosphonates, which are also associated with avascular osteonecrosis of the jaw (ONJ). Our aim was to evaluate the correlation between bisphosphonates and ONJ. Of the 539 patients with bone metastases treated in our department from June 2002 to December 2006 with i.v. bisphosphonates, eight (1.5%) developed ONJ. The eight patients with ONJ had all been given zoledronic acid, and two had also been treated with pamidronic acid. In four of the patients, ONJ was diagnosed during treatment, while in the remaining four it was diagnosed several months after therapy with bisphosphonates had ended. Six of these patients received local noninvasive treatment, of whom five progressed. Two showed apparent autolimitation of the disease. The remaining two patients underwent surgical resection and currently show no signs of relapse. All eight ONJ patients presented with various concomitant risk factors such as paradontopathy, dental extraction, or spontaneous avulsion. Our results show that ONJ can appear months after interruption of treatment and that a surgical approach can be used in suitable cases. Closer cooperation is needed among specialists to define guidelines for the prevention of ONJ in patients with bone metastases.

  20. Comparison of bone mineral density in the jaws of patients with and without chronic periodontitis

    PubMed Central

    Öztürk Tonguç, M; Ş Büyükkaplan, U; Fentoğlu, Ö; A Gümüş, B; S Çerçi, S; Y Kırzıoğlu, F

    2012-01-01

    Objectives Although several studies have addressed the relationship between systemic bone mineral status and the severity of periodontitis, there is little knowledge of the relationship between periodontal disease and locally detected bone mineral density. The aim of this study was to compare the mandibular bone mineral density of patients with chronic periodontitis with that of periodontally healthy subjects. Methods 48 systemically healthy subjects were included in the study and underwent a periodontal examination to determine their status. 24 subjects were periodontally healthy and the other 24 had moderate or severe chronic periodontitis. The mandibular bone mineral density of the subjects was determined by dual energy X-ray absorptiometry. The region of interest on the body of the mandible was independently determined on the dual energy absorptiometry radiographs, and a computer calculated the bone mineral density of these regions. Results The mandibular bone mineral density of the subjects with periodontitis was significantly lower than that of the periodontally healthy subjects (p < 0.01). There were significant negative correlations between the mandibular bone mineral density values and parameters related to the amount of periodontal destruction. Conclusions Low bone mineral density in the jaw may be associated with chronic periodontitis. PMID:22241867

  1. Osteonecrosis of the jaw in patients with cancer who received zoledronic acid and bevacizumab.

    PubMed

    Francini, Filippo; Pascucci, Alessandra; Francini, Edoardo; Miano, Salvatora Tindara; Bargagli, Gianluca; Ruggiero, Grazia; Petrioli, Roberto

    2011-05-01

    The authors investigated the incidence of and risk factors for osteonecrosis of the jaw (ONJ) in patients with metastases to the bone who received the bisphosphonate agent zoledronic acid (ZOL) and chemotherapy combined with the antiangiogenic agent bevacizumab (BEV). The authors evaluated 59 participants (34 with breast cancer and 25 with nonsmall-cell lung cancer). All of the participants received 4 milligrams of ZOL via intravenous (IV) infusion every four weeks and 15 mg per kilogram of BEV every three weeks. They conducted a dental examination in participants at baseline and every three months until the patients died or were lost to follow-up. If needed, participants received periodontal disease treatment and underwent tooth extraction before they started receiving ZOL and BEV. The median time the participants received ZOL therapy was 18.8 months (range, 3.1-28.9 months); 36 participants (61.0 percent) received ZOL therapy for more than one year. The median time participants received BEV therapy was 16.7 months (range, 2.8-29.6 months). None of the participants required dentoalveolar surgery while undergoing cancer treatment. After a median follow-up period of 19.7 months, none of the participants developed bisphosphonate-related ONJ. ZOL combined with BEV did not predispose to ONJ participants with cancer that had metastasized to the bone who underwent a baseline dental examination and preventive dental measures. The study results must be considered in the context of the study's protocols and the follow-up period.

  2. Osteonecrosis of jaws related to intravenous bisphosphonates: the experience of a Jordanian teaching hospital

    PubMed Central

    Baqain, Zaid H; Sawair, Faleh A; Tamimi, Zaid; Bsoul, Nazzal; Al Edwan, Ghazi; Almasad, Jamal K; Abbadi, Abdalla A

    2010-01-01

    INTRODUCTION We describe our experience with oncology patients on a frequent dosing schedule of intravenous (i.v.) bisphosphonates at the Jordan University Hospital (JUH). PATIENTS AND METHODS Patients treated by i.v. bisphosphonates in the medical oncology unit at the JUH were examined for bisphosphonate-related osteonecrosis of the jaws (BRONJ). Diagnosis was made according to the guidelines of the American Association of Oral and Maxillofacial Surgeons (AAOMS) original position paper. RESULTS Of the 41 patients, four developed BRONJ, two in maxilla, one in mandible and one bimaxillary. Patients with BRONJ were older; mean age was 69.3 ±3.1 years compared to 62.8 ± 12.5 years (P = 0.022). Dental co-morbidities were more commonly present in patients with the disease (P = 0.038). Patients who developed BRONJ were on treatment for a longer duration of time; the mean duration of treatment was 23.5 ± 8.4 months compared to 11.9 ± 13.4 months (P = 0.10). CONCLUSIONS The results of this case series demonstrated that age and poor oral health status are significant risk factors of BRONJ for oncology patients on long-term frequent dosing schedule of i.v. bisphosphonates. PMID:20522306

  3. Incidence and risk predictors for osteonecrosis of the jaw in cancer patients treated with intravenous bisphosphonates.

    PubMed

    Kos, Marcin

    2015-04-25

    The aim of this study was to establish the incidence of bisphosphonate-related osteonecrosis of the jaws (BRONJ) in oncologic patients and to determine risk predictors with respect to this condition. This retrospective review included 197 oncologic patients treated from January 2005 to December 2010 with administration of bisphosphonates (BPs) as part of management. Sex, age, type of cancer diagnosed, period of substantial disease, oral surgery, type of bisphosphonate, number of doses, and cases of BRONJ diagnosis were recorded. The cumulative incidence and incidence rate of BRONJ were calculated. The factors that influenced BRONJ were assessed with multivariate logistic regression and with estimations of 95% confidence intervals and odd ratios. Values of p ≤ 0.05 were considered significant. The BRONJ appeared in 9.64% of patients. The BRONJ incidence rate was 1 in 28 patients per year of BP treatment. Logistic regression showed that the odds of osteonecrosis increased 1.0172-fold with each given dose of BP. The BRONJ risk with zoledronate was 5-fold higher than that with pamidronate or ibandronate. The risk of BRONJ increased by 40-fold after dental surgery. Period of BP administration and type of BP used are important risk predictors for the development of BRONJ in oncologic patients treated with intravenous administration of these drugs. Patient-related factors are dental or periodontal events connected with need for oral surgery.

  4. Ewing’s Sarcoma Family Tumors in the Jaws: Case Report, Immunohistochemical Analysis and Literature Review

    PubMed Central

    CASAROTO, ANA REGINA; SAMPIERI, MARCELO BONIFACIO DA SILVA; SOARES, CLEVERSON TEIXEIRA; SANTOS, PAULO SERGIO DA SILVA; YAEDU, RENATO YASSUTAKA FARIA; DAMANTE, JOSÉ HUMBERTO; LARA, VANESSA SOARES

    2017-01-01

    Due to the low incidence of the Ewing’s Sarcoma (ES) family tumors, the available epidemiology is likely to be unreliable, and at present, there are no standard diagnostic or clinical guidelines outlining their management. This report describes a case of peripheral primitive neuroectodermal tumor (ES/pPNET) which initially mimicked cystic lesions, and describes a comparison between ES and ES/pPNET in the jaws by the World Health Organization classification. This review addressed 63 cases published in the English literature between 1950 and 2016. The majority of cases were ES. Both ES and ES/pPNET mimicked other benign entities such as traumatic, cystic and inflammatory lesions. The patients who died of their disease had a history of metastatic tumors, and primary tumor located in the mandible and maxilla for ES and ES/pPNET, respectively. The differentiation of the ES family tumors from other small blue-cell tumors may be difficult and requires familiarity with histological and immunohistochemical features. PMID:28438883

  5. Medication-Related Osteonecrosis of the Jaw: New Insights into Molecular Mechanisms and Cellular Therapeutic Approaches

    PubMed Central

    Lombard, Thomas; Neirinckx, Virginie; Gilon, Yves

    2016-01-01

    In recent years, medication-related osteonecrosis of the jaw (MRONJ) became an arising disease due to the important antiresorptive drug prescriptions to treat oncologic and osteoporotic patients, as well as the use of new antiangiogenic drugs such as VEGF antagonist. So far, MRONJ physiopathogenesis still remains unclear. Aiming to better understand MRONJ physiopathology, the first objective of this review would be to highlight major molecular mechanisms that are known to be involved in bone formation and remodeling. Recent development in MRONJ pharmacological treatments showed good results; however, those treatments are not curative and could have major side effects. In parallel to pharmacological treatments, MSC grafts appeared to be beneficial in the treatment of MRONJ, in multiple aspects: (1) recruitment and stimulation of local or regional endogenous cells to differentiate into osteoblasts and thus bone formation, (2) beneficial impact on bone remodeling, and (3) immune-modulatory properties that decrease inflammation. In this context, the second objective of this manuscript would be to summarize the molecular regulatory events controlling osteogenic differentiation, bone remodeling, and osteoimmunology and potential beneficial effects of MSC related to those aspects, in order to apprehend MRONJ and to develop new therapeutic approaches. PMID:27721837

  6. Bisphosphonate-associated osteonecrosis of the jaw. A proposal for conservative treatment.

    PubMed

    Pérez, Sacramento Bocanegra; Barrero, Mario Vicente; Hernández, Manuel Sosa; Knezevic, Milan; Navarro, José María Castellano; Millares, José Rodríguez

    2008-12-01

    The use of bisphosphonates (BPs) has proven effective in the treatment of bone-related diseases, despite the potential risk of developing osteonecrosis of the jaw (ONJ). So far, results for the treatment of ONJ have not been satisfactory. In our study, we have treated two patients diagnosed with ONJ. In addition to local treatments a hydrogel was applied, with promising results. The fistulae disappeared 2-3 weeks into the treatment. After a six-month follow-up period there has been no sign of recurrence. The extent of maxillary bone exposure has diminished notably, although not entirely disappeared. In all cases, the patients exhibit no other symptoms (they suffer from no pain or swelling or functional impotence). For this reason we believe this protocol might be useful in the case of patients who suffer from pain and fistulation secondary to BP-associated ONJ to improve the state of their lesions until definitive treatment can be undertaken. Although these findings are not conclusive, given that we are reporting data on two patients only, we believe that this might be an alternative treatment in refractory cases where other therapies are counter-indicated. A controlled randomized and prospective study would be required to confirm our findings.

  7. ANTIBIOTIC EFFECTS ON BACTERIAL PROFILE IN OSTEONECROSIS OF THE JAW

    PubMed Central

    Ji, Xiaojie; Pushalkar, Smruti; Li, Yihong; Glickman, Robert; Fleisher, Kenneth; Saxena, Deepak

    2011-01-01

    OBJECTIVE Oral infection is considered to play a critical role in the pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ) and antibiotic therapy has become a mainstay of BRONJ therapy. This study was aimed to investigate the effect of antibiotics on bacterial diversity in BRONJ tissues. MATERIALS AND METHODS The bacterial profile from soft tissues associated with the BRONJ lesion was determined using 16S rRNA-based denaturing gradient gel electrophoresis (DGGE) and sequencing. Twenty BRONJ subjects classified as stage 0 to 2 were enrolled in this study and patient groups were divided into an antibiotic cohort (n=10) treated with systemic antibiotic and a non-antibiotic cohort (n=10) with no prior antibiotic therapy. RESULTS The DGGE fingerprints indicated no significant differences in bacterial diversity of BRONJ tissue samples. Patients on antibiotics had higher relative abundance of phylum Firmicutes with bacterial species, Streptococcus intermedius, Lactobacillus gasseri, Mogibacterium timidum and Solobacterium moorei whereas patients without antibiotics had greater amounts of Parvimonas micra, and S. anginosus. Thirty percent of bacterial populations were uncultured (yet-to be cultured) phylotypes. CONCLUSION This study using limited sample size indicated that oral antibiotic therapy may have a limited efficacy on the bacterial population associated with BRONJ lesions. PMID:21883710

  8. Osteonecrosis of the jaw associated with everolimus: A case report

    PubMed Central

    Yamamoto, Daigo; Tsubota, Yu; Utsunomiya, Toshiki; Sueoka, Noriko; Ueda, Aiko; Endo, Kayoko; Yoshikawa, Katsuhiro; Kon, Masanori

    2017-01-01

    Everolimus, a mammalian target of rapamycin inhibitor, has recently been approved for the treatment of metastatic estrogen receptor-positive breast cancer, at a daily dose of 10 mg in combination with exemestane. Osteonecrosis of the jaw (ONJ) is a rare but severe condition, characterized by exposed necrotic bone, and is associated with various drugs that are often used to treat advanced malignancies. We herein report the case of a patient with breast cancer who developed ONJ during treatment with everolimus, which improved after discontinuation of the drug. To the best of our knowledge, this is the first reported case of everolimus-associated ONJ in a patient receiving everolimus for metastatic breast cancer. In 2014, an 80-year-old woman was started on treatment with everolimus and exemestane for stage IIB estrogen receptor-positive breast cancer. Within 2 months, the left side of her face became edematous, with localized heat and tenderness of the left mandibular region and a 3-mm round area of exposed bone. There was purulent discharge and the surrounding gingiva was edematous and erythematous. The left mandible exhibited a low signal intensity area on T1-weighted magnetic resonance imaging. Treatment was discontinued and ONJ showed improvement after 2 months. Therefore, when prescribing everolimus for metastatic breast cancer, oncologists should be aware of the possibility of ONJ as a complication. PMID:28357105

  9. Concurrent simulation of a parallel jaw end effector

    NASA Technical Reports Server (NTRS)

    Bynum, Bill

    1985-01-01

    A system of programs developed to aid in the design and development of the command/response protocol between a parallel jaw end effector and the strategic planner program controlling it are presented. The system executes concurrently with the LISP controlling program to generate a graphical image of the end effector that moves in approximately real time in response to commands sent from the controlling program. Concurrent execution of the simulation program is useful for revealing flaws in the communication command structure arising from the asynchronous nature of the message traffic between the end effector and the strategic planner. Software simulation helps to minimize the number of hardware changes necessary to the microprocessor driving the end effector because of changes in the communication protocol. The simulation of other actuator devices can be easily incorporated into the system of programs by using the underlying support that was developed for the concurrent execution of the simulation process and the communication between it and the controlling program.

  10. Use of larder beetles (Coleoptera: Dermestidae) to deflesh human jaws.

    PubMed

    Charabidze, D; Colard, T; Becart, A; Hedouin, V

    2014-01-01

    We describe new experimental data for the defleshing of human bones using larder beetles (Dermestes haemorrhoidalis) (Küster, 1852). Although the ability of larder beetles to feed on vertebrate remains has been, and still is, used by taxidermists to deflesh skulls and bones, this method has never been documented from a quantitative perspective and has over time become ignored in most forensic anthropology or odontology laboratories. To promote the rational and efficient use of this method, we performed experiments to estimate the quantity of food consumed by larvae. From the 2nd instar to nymphosis, each larva consumed a mean of 0.13±0.03 g of dry beef muscle. We then used 100±50 D. haemorrhoidalis adults and 100±50 larvae to deflesh human maxillae and mandibles sampled within a forensic context (victim identification). Each sample was weighed and photographed before, during and after the experiment. According to our experiments, 20-25 days were sufficient to completely deflesh all of the samples. We concluded that a small number of larder beetles can be used to efficiently deflesh human jaws. According to this result, the use of larder beetles appears to be an inexpensive, simple and efficient way to clean mandibles and maxillae. Furthermore, this method is DNA-safe (compared to usual maceration techniques) and thus allows the samples to be used for subsequent DNA and drug analyses.

  11. Mandibular symphysis morphology and dimensions in different anteroposterior jaw relationships.

    PubMed

    Al-Khateeb, Susan N; Al Maaitah, Emad F; Abu Alhaija, Elham S; Badran, Serene A

    2014-03-01

    To assess the morphology and dimensions of mandibular symphysis (MS) in different anteroposterior jaw relationships and to investigate whether craniofacial parameters have any correlation with its shape and/or dimensions. Lateral cephalograms of subjects with Class I, Class II, and Class III skeletal relationships were traced. Several craniofacial and MS parameters were measured. MS parameters were compared between the three groups using analysis of variance and were correlated with the craniofacial parameters using the Pearson correlation coefficient. Larger angle of concavity of the chin, more inclination of the alveolar bone toward the mandibular plane, and larger MS dimensions and area (P < .001) were found with a Class III skeletal relationship compared to Class I and Class II relationships. The Pearson correlation coefficient between Id-Me and AFH was r  =  0.83 and between Id-Me and LAFH it was r  =  0.81. The dimensions and configuration of MS in the Class III relationship were different than those in Class I and Class II relationships; the alveolar part of MS compensated for the skeletal relationship in the Class III pattern. MS dimensions were strongly correlated to anterior facial dimensions.

  12. Analysis of Dental Maturation in Relation to Sagittal Jaw Relationships

    PubMed Central

    Durka-Zając, Magdalena; Derwich, Marcin; Mituś-Kenig, Maria; Łoboda, Magdalena; Pawłowska, Elżbieta

    2017-01-01

    Summary Background The degree of mineralization of permanent tooth germs in dental age assessment has been an area of interest among many authors for years. However, only recently have researchers attempted to determine the potential interdependencies between dental age and jaw relationships. The aim of this work was to compare dental maturation in patients with skeletal Class II to patients with skeletal Classes I and III. Material/Methods The study involved 150 patients who sought orthodontic treatment. Dental age was assessed from panoramic radiographs using the Demirjian’s method. Skeletal class was evaluated according to the value of the ANPg angle from the Björk’s analysis. We used the analysis of variance (ANOVA) and the Student’s t-test. Results The mean dental age in patients with skeletal Class III was significantly higher than the mean dental age in patients with skeletal Class II (p<0.0005). A correlation between the dental age and chronological age was established. The weakest correlation was seen between the dental age and skeletal Class II. Among patients with skeletal Class II, the strongest correlation was found between chronological age and the formation of the germ of the second lower premolar (r=0.67; p<0.001). Conclusions Dental age among patients with skeletal Class II was the lowest. PMID:28203310

  13. Total face, double jaw, and tongue transplantation: an evolutionary concept.

    PubMed

    Dorafshar, Amir H; Bojovic, Branko; Christy, Michael R; Borsuk, Daniel E; Iliff, Nicholas T; Brown, Emile N; Shaffer, Cynthia K; Kelley, T Nicole; Kukuruga, Debra L; Barth, Rolf N; Bartlett, Stephen T; Rodriguez, Eduardo D

    2013-02-01

    The central face high-energy avulsive injury has been frequently encountered and predictably managed at the R Adams Cowley Shock Trauma Center. However, despite significant surgical advances and multiple surgical procedures, the ultimate outcome continues to reveal an inanimate, insensate, and suboptimal aesthetic result. To effectively address this challenging deformity, a comprehensive multidisciplinary approach was devised. The strategy involved the foundation of a basic science laboratory, the cultivation of a supportive institutional clinical environment, the innovative application of technologies, cadaveric simulations, a real-time clinical rehearsal, and an informed and willing recipient who had the characteristic deformity. After institutional review board and organ procurement organization approval, a total face, double jaw, and tongue transplantation was performed on a 37-year-old man with a central face high-energy avulsive ballistic injury. This facial transplant represents the most comprehensive transplant performed to date. Through a systematic approach and clinical adherence to fundamental principles of aesthetic surgery, craniofacial surgery, and microsurgery and the innovative application of technologies, restoration of human appearance and function for individuals with a devastating composite disfigurement is now a reality. Therapeutic, V.

  14. The effect of various jaw motor tasks on body sway.

    PubMed

    Hellmann, Daniel; Giannakopoulos, N N; Blaser, R; Eberhard, L; Schindler, H J

    2011-10-01

    Alterations of body sway caused by isometric contractions of the jaw muscles have been reported previously. The objective of this study was to test if motor tasks of the masticatory system with different control demands affect body posture differently during quiet stance. Position and sway displacements of the center of foot pressure (COP) were measured for 20 healthy subjects who either kept the mandible at rest or performed unilateral and bilateral maximum voluntary teeth clenching, feedback-controlled biting tasks at submaximum bite forces, or unilateral chewing. Two weeks later the measurements were repeated. Compared with quiet stance, the COP results revealed significant changes during the feedback-controlled biting tasks. Robust sway reduction and anterior displacement of the COP were observed under these conditions. Body oscillations were not significantly affected by maximum bites or by unilateral chewing. For most of the variables investigated there were no significant differences between unilateral and bilateral biting. Robust sway reduction during feedback-controlled biting tasks in healthy subjects involved a stiffening phenomenon that was attributed to the common physiological repertoire of posture control, and might optimize the stability of posture under these conditions. © 2011 Blackwell Publishing Ltd.

  15. [The atrophic jaw from the dental surgeon's point of view].

    PubMed

    Obwegeser, H

    1977-09-01

    A report on 3000 cases of jaw atrophy over a period of 20 years. These cases underwent surgery and the results were obtained on the basis of close collaboration between maxillofacial surgery and prosthetics. Certain deductions could be obtained from these numerous patients over a longe period of observation. It is now possible to separate wistful thinking from reality. Subperiosteal implants have, in spite of chronic infections, functioned over a period of 10 years and more. Enossal implants seem to do the same for partial prosthetics. Complete failure of either form of implant is to be expected in edentulous mouths. Loss of a subperiosteal or enossal implant generally leaves a condition requiring new surgical intervention. The methods of vestibuloplasty, tuberoplasty and lowering of the floor of the mouth have been generally successful, if proper indication, surgical technique and prosthetic rehabilitation are observed by competent professionals. In plastic surgery of the alveolar process the use of ribs has been successful in this clinic. Even though postoperative resorption may destroy 50% and more of the obtained height of the alveolar process, the results justify this kind of surgery. The obtained results suggest that the methods described have justified their due place in maxillofacial surgery, because they may be considered to be results at long term.

  16. Neural crest-mediated bone resorption is a determinant of species-specific jaw length

    PubMed Central

    Ealba, Erin L.; Jheon, Andrew H.; Hall, Jane; Curantz, Camille; Butcher, Kristin D.; Schneider, Richard A.

    2015-01-01

    Precise control of jaw length during development is crucial for proper form and function. Previously we have shown that in birds, neural crest mesenchyme (NCM) confers species-specific size and shape to the beak by regulating molecular and histological programs for the induction and deposition of cartilage and bone. Here we reveal that a hitherto unrecognized but similarly essential mechanism for establishing jaw length is the ability of NCM to mediate bone resorption. Osteoclasts are considered the predominant cells that resorb bone, although osteocytes have also been shown to participate in this process. In adults, bone resorption is tightly coupled to bone deposition as a means to maintain skeletal homeostasis. Yet, the role and regulation of bone resorption during growth of the embryonic skeleton have remained relatively unexplored. We compare jaw development in short-beaked quail versus long-billed duck and find that quail have substantially higher levels of enzymes expressed by bone-resorbing cells including tartrate-resistant acid phosphatase (TRAP), Matrix metalloproteinase 13 (Mmp13), and Mmp9. Then, we transplant NCM destined to form the jaw skeleton from quail to duck and generate chimeras in which osteocytes arise from quail donor NCM and osteoclasts come exclusively from the duck host. Chimeras develop quail-like jaw skeletons coincident with dramatically elevated expression of TRAP, Mmp13, and Mmp9. To test for a link between bone resorption and jaw length, we block resorption using a bisphosphonate, osteoprotegerin protein, or an MMP13 inhibitor, and this significantly lengthens the jaw. Conversely, activating resorption with RANKL protein shortens the jaw. Finally, we find that higher resorption in quail presages their relatively lower adult jaw bone mineral density (BMD) and that BMD is also NCM-mediated. Thus, our experiments suggest that NCM not only controls bone resorption by its own derivatives but also modulates the activity of mesoderm

  17. [Biomechanics of the jaw apparatus in the horn-shark (Heterodontus portusjacksoni = Heterodontus philippi)].

    PubMed

    Nobiling, G

    1977-01-01

    The constructional morphology of the jaw apparatus in the horn-shark Heterodontus has been investigated. The origines and insertions of the jaw muscles have been delimited and the lines of action were determined. The individual muscles have been weighed, in order to get on the basis of their masses an estimate of the forces which are exerted by the components of the jaw musculature. The mandibular joints, the occlusion of the jaws, morphological details of the upper and lower jaws as well as the "subodontium" have been subject to macroscopic and microscopic study. The joint between palatoquadrate and mandibular consists of a medial and a lateral compartment. Only hinge movements are possible. If the jaws are closed, the contacts between upper and lower jaws are confined to the large crushing teeth of only one or two tooth families. The teeth are fixed to the jaw cartilage by ligamentous structures. Three layers can be discerned histologically: The uppermost layer, beneath the bases of the teeth, is composed of the fibrae interdentales and of the fibrae subbasales. By these, the individual teeth are firmly connected to form a continuous pavement. - The middle layer is characterised by the great number of cell nuclei. - The fibre system which constitutes the lowermost layer is arranged according to its function. The subdental layer of fibrous tissue grows faster than the one adjacent to the jaws. Thus a particular growth structure is formed. - Two constructive principles are realised: 1. The biting forces or "loads", applied to one or two teeth, are split and distributed on all teeth of the same family which are lingual of the loaded one. 2. As in the thecodont mammals, the compressive biting (= occlusal) force is transformed into a tensile force by the tooth-fixing apparatus and by the shapes of the jaws and this is sustained by fibrous structures. Magnitude and directions of the stresses which appear in the upper and lower jaw during biting are compared with stress

  18. [A case of bisphosphonate-related osteonecrosis of the jaw in a patient who had received intravenous bisphosphonates].

    PubMed

    Ishikawa, Tohru

    2014-02-01

    Bisphosphonates(BPs)have been widely used for the treatment of hypercalcemia associated with cancer, multiple myeloma bone diseases, and bone metastasis of solid cancers. Many cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ)have been reported in Japan. We report a case of a patient who developed BRONJ after tooth extraction even though the administration of BPs had been discontinued for 23 months. The patient was a 74-year-old woman who had received intravenous BPs from 2003 through 2008. She underwent tooth extraction in 2010. The bone in the extraction socket was exposed for more than 8 weeks. A clinical diagnosis of BRONJ was made. Discontinuation of BPs before surgical dental treatment did not appear to prevent BRONJ in this patient who had received intravenous BPs.

  19. Opportunistic actinomycosis in osteoradionecrosis of the jaws in patients affected by head and neck cancer: incidence and clinical significance.

    PubMed

    Curi, M M; Dib, L L; Kowalski, L P; Landman, G; Mangini, C

    2000-05-01

    Actinomycosis is occasionally an opportunistic infection occurrence in patients with osteoradionecrosis (ORN). A retrospective study (1992-97) of 50 patients with ORN of the jaws was done to evaluate the incidence and its clinical significance in the management of ORN. Actinomycosis was diagnosed in 12% of ORN cases. In 36 of the 50 patients including five cases of actinomycosis, the ORN was considered to be resolved after treatment. The median treatment duration of ORN was significantly longer (P<0.007) in patients with actinomycosis (29.7 months) than those without the disease (13.4 months). In conclusion, bone biopsy should be considered in cases of ORN with unsatisfactory response to its specific therapies, aiming to identify possible opportunistic actinomycosis infection.

  20. Suppression of jaw-opening and trigemino-hypoglossal reflexes during swallowing in the cat.

    PubMed

    Ono, T; Ishiwata, Y; Kuroda, T; Nakamura, Y

    1999-11-01

    Jaw-opening and trigemino-hypoglossal reflexes can be evoked by innocuous as well as noxious afferents from intra-oral structures. It has been reported that the amplitude of the jaw-opening reflex evoked by weak electrical stimulation of the upper lip is subject not only to tonic suppression but also to phase-linked modulation during mastication. In this study, we investigated whether the jaw-opening and trigemino-hypoglossal reflexes are modulated during swallowing. Data were obtained from 8 chloralose-anesthetized cats. Reflexes were monitored by electromyographic activities recorded from the anterior digastric, genioglossus, and styloglossus muscles and, after paralysis, by the efferent discharge in the digastric and hypoglossal nerves. Swallowing was elicited either by water dropped on the tongue or by repetitive stimulation of the superior laryngeal nerve. Jaw-opening and trigemino-hypoglossal reflexes were evoked by stimulation of the lingual nerve, and the evoked afferent volley was recorded from the Gasserian ganglion so that the threshold of the lingual nerve could be determined. The following results were obtained: (1) The jaw-opening and trigemino-hypoglossal reflexes evoked by stimulation of the low-threshold, but not high-threshold, lingual afferents were remarkably suppressed during swallowing; and (2) both the jaw-opening and trigemino-hypoglossal reflexes evoked by low-threshold lingual afferents were suppressed during fictive swallowing after the animals were paralyzed. We conclude that the jaw-opening and trigemino-hypoglossal reflexes evoked by low-threshold lingual afferents are suppressed during swallowing by a central motor program.

  1. Morphology and biomechanics of the pinniped jaw: mandibular evolution without mastication.

    PubMed

    Jones, Katrina E; Ruff, Christopher B; Goswami, Anjali

    2013-07-01

    Pinnipeds (seals, sea lions, and walruses) underwent a shift in jaw function away from typical carnivoran mastication to more novel marine behaviors during the terrestrial-aquatic transition. Here we test the effect of aquatic prey capture and male-male combat on the morphological evolution of a mammal jaw that does not masticate. Nine three-dimensional landmarks were taken along the mandible for 25 species (N = 83), and corpus and symphysis external and cortical breadths for a subset of five species (N = 33). Principal components analysis was performed on size-corrected landmark data to assess variation in overall jaw morphology across pinnipeds. Corpus breadths were input to a beam model to calculate strength properties and estimated bite force of specific species with contrasting behaviors (filter feeding, suction feeding, grip-and-tear feeding, and male-male combat). Results indicate that, although phylogenetic signal in jaw shape is strong, function is also important in determining morphology. Filter feeders display an elongate symphysis and a long toothrow that may play a role in filtering krill. Grip-and-tear feeders have a long jaw and large estimated bite force relative to non-biting species. However, the largest estimated bite forces were observed in males of male-male combative species, likely due to the high selection pressure associated with male success in highly polygynous species. The suction feeding jaw is weak in biting but has a different morphology in the two suction feeding taxa. In conclusion, familial patterns of pinniped jaw shape due to phylogenetic relatedness have been modified by adaptations to specialized behavior of individual taxa.

  2. Involvement of the maxillary sinus in bisphosphonate-related osteonecrosis of the jaw: Radiologic aspects.

    PubMed

    Wasserzug, Oshri; Kaffe, Israel; Lazarovici, Towy Sorel; Weissman, Tal; Yahalom, Ran; Fliss, Dan M; Yarom, Noam

    2017-01-01

    The use of bisphosphonates is very common among patients with osteoporosis and multiple myeloma as well as those with bone metastases from various malignancies. The benefits of bisphosphonates are well recognized, but it became evident during the past decade that these medications portend the major adverse effect of osteonecrosis of the jaw, known as bisphosphonate-related osteonecrosis of the jaw. Our aim was to evaluate the specific manifestations of bisphosphonate use on the maxillary sinus in patients with documented bisphosphonate-related osteonecrosis of the jaw. A retrospective review of all the patients diagnosed between October 2003 to August 2014 as having bisphosphonate-related osteonecrosis of the jaw in a large university-affiliated tertiary care medical center. The records of 173 patients diagnosed as having bisphosphonate-related osteonecrosis of the jaw during the study period were retrieved. The available head and neck computed tomographic images were analyzed for cases of involvement of the maxilla. Manifestations of bisphosphonate-related osteonecrosis of the jaw as observed on physical examination and on imaging studies. Seventy-one patients (41%) had involvement of the maxilla, 86 patients (49%) had involvement of the mandible, and 16 patients (9%) had involvement of both the maxilla and the mandible. Computerized tomography studies were available for 50 patients with involvement of the maxilla: 36 (72%) had evidence of maxillary sinus opacification (in comparison, the incidence of maxillary sinus opacification as an incidental finding in the general population is reported to be 19%, p < 0.0001). Sixteen patients (32%) had evidence of oroantral fistula, and five patients (10%) had oronasal fistula. In addition to its well-established effects on the mandible and maxilla, bisphosphonate-related osteonecrosis of the jaw significantly affected the maxillary sinus. Its radiologic manifestations should be recognized by clinicians and especially by

  3. Disparities in Utilization of Jaw Surgery for Treatment of Sleep Apnea: A Nationwide Analysis

    PubMed Central

    Shan, Ying; Havlena, Jeffrey A.; Afifi, Ahmed M.

    2016-01-01

    Background: Maxillomandibular advancement has been shown to be one of the most effective operations for management of severe obstructive sleep apnea, yet pharyngeal surgery is more commonly performed. The goal of this study was to identify socioeconomic factors associated with this phenomenon. Methods: Patients aged 14 or older with a primary hospital diagnosis of sleep apnea were identified using the National Inpatient Sample from 2005 to 2012. ICD9 codes were used to determine whether a pharyngeal or jaw procedure was performed. Patient demographics, comorbidities, and complications were compared. Results: Among 6316 sleep surgeries, 5964 (94.4%) were pharyngeal and 352 (5.6%) were jaw procedures. Women were significantly more likely to receive jaw surgery than men (odds ratio [OR] = 1.68, P = 0.0007). African Americans (OR = 0.19, P < 0.0001), Hispanics (OR = 0.42, P = 0.0009), Asians (OR = 0.41, P = 0.0009), and other non-Caucasians (OR = 0.19, P = 0.0008) had a significantly lower odds of receiving jaw surgery than Caucasians. Patients falling into lower-income brackets (OR = 0.39 and 0.57, P = 0.02 and 0.04) and patients with Medicare compared with private or Health Maintenance Organization insurance (OR = 0.46, P = 0.008) also had significantly decreased odds of undergoing jaw surgery. Comorbidities were similar between surgical groups, and there were no significant differences in bleeding, infection, or cardiopulmonary complications. Conclusions: We identified no significant difference in complication rates between pharyngeal and jaw procedures. Nonetheless, African American, Hispanic, and Asian patients, in addition to lower-income patients and patients with Medicare, had a significantly lower odds of receiving jaw surgery. Awareness of these disparities may help guide efforts to improve patients’ surgical options for sleep apnea. PMID:28293491

  4. Comparison of Performance Characteristics of Oval Cup Forceps Versus Serrated Jaw Forceps in Gastric Biopsy.

    PubMed

    Sussman, Daniel A; Deshpande, Amar R; Shankar, Uday; Barkin, Jodie A; Medina, Ana Maria; Poppiti, Robert J; Cubeddu, Luigi X; Barkin, Jamie S

    2016-08-01

    Obtaining quality endoscopic biopsy specimens is vital in making successful histological diagnoses. The influence of forceps cup shape and size on quality of biopsy specimens is unclear. To identify whether oval cup or two different serrated jaw biopsy forceps could obtain specimens of superior size. Secondary endpoints were tissue adequacy, depth of tissue acquisition, and crush artifact. A single-center, prospective, pathologist-masked, randomized controlled trial was performed. In total 136 patients with a clinical indication for esophagogastroduodenoscopy with biopsy were randomized to receive serial biopsies with a large-capacity serrated forceps with jaw diameter 2.2 mm (SER1) and either a large-capacity oval forceps with jaw diameter 2.4 mm (OVL) or large-capacity serrated biopsy forceps with jaw diameter 2.4 mm (SER2) in two parallel groups. SER2 provided significantly larger specimens than did the other forceps (SER2 3.26 ± 1.09 vs. SER1 2.92 ± 0.88 vs. OVL 2.92 ± 0.76; p = 0.026), with an average size difference of 0.34 mm greater with SER2 compared to SER1 and OVL. OVL provided significantly deeper biopsies compared to SER1 and SER2 (p = 0.02), with 31 % of OVL biopsies reaching the submucosa. SER2 had significantly less crush artifact than SER1 and OVL (p < 0.0001). Serrated forceps provided larger samples compared to oval jaw forceps of the same size, with SER2 providing the largest specimen size. Oval cup forceps had deeper penetration of epithelium, while the larger jaw diameter serrated jaw forceps had less crush artifact. All three forceps provided specimens adequate for diagnostic purposes.

  5. Evaluation of the Quantitative Accuracy of 3D Reconstruction of Edentulous Jaw Models with Jaw Relation Based on Reference Point System Alignment

    PubMed Central

    Li, Weiwei; Yuan, Fusong; Lv, Peijun; Wang, Yong; Sun, Yuchun

    2015-01-01

    Objectives To apply contact measurement and reference point system (RPS) alignment techniques to establish a method for 3D reconstruction of the edentulous jaw models with centric relation and to quantitatively evaluate its accuracy. Methods Upper and lower edentulous jaw models were clinically prepared, 10 pairs of resin cylinders with same size were adhered to axial surfaces of upper and lower models. The occlusal bases and the upper and lower jaw models were installed in the centric relation position. Faro Edge 1.8m was used to directly obtain center points of the base surface of the cylinders (contact method). Activity 880 dental scanner was used to obtain 3D data of the cylinders and the center points were fitted (fitting method). 3 pairs of center points were used to align the virtual model to centric relation. An observation coordinate system was interactively established. The straight-line distances in the X (horizontal left/right), Y (horizontal anterior/posterior), and Z (vertical) between the remaining 7 pairs of center points derived from contact method and fitting method were measured respectively and analyzed using a paired t-test. Results The differences of the straight-line distances of the remaining 7 pairs of center points between the two methods were X: 0.074 ± 0.107 mm, Y: 0.168 ± 0.176 mm, and Z: −0.003± 0.155 mm. The results of paired t-test were X and Z: p >0.05, Y: p <0.05. Conclusion By using contact measurement and the reference point system alignment technique, highly accurate reconstruction of the vertical distance and centric relation of a digital edentulous jaw model can be achieved, which meets the design and manufacturing requirements of the complete dentures. The error of horizontal anterior/posterior jaw relation was relatively large. PMID:25659133

  6. Postsurgical volumetric airway changes in 2-jaw orthognathic surgery patients.

    PubMed

    Hart, P Sheamus; McIntyre, Brian P; Kadioglu, Onur; Currier, G Fräns; Sullivan, Steven M; Li, Ji; Shay, Christina

    2015-05-01

    Findings from early cephalometric studies on airway changes after 2-jaw orthognathic surgery have been challenged because the previous anteroposterior interpretation of airway changes can now be evaluated in 3 dimensions. The aims of this study were to use cone-beam computed tomography to quantify the nasopharynx, oropharynx, and total airway volume changes associated with skeletal movements of the maxilla and mandible in a sample of patients undergoing 2-jaw orthognathic surgery for correction of skeletal malocclusion. Skeletal movements and airway volumes of 71 postpubertal patients (31 male, 40 female; mean age, 18.8 years) were measured. They were divided into 2 groups based on ANB angle, overjet, and occlusion (Class II: ANB, >2°; overjet, >1 mm; total, 35 subjects; and Class III: ANB, <1°; overjet, <1 mm; total, 36 subjects). Presurgical and postsurgical measurements were collected for horizontal, vertical, and transverse movements of the maxilla and the mandible, along with changes in the nasopharynx, oropharynx, and total airways. Associations between the directional movements of skeletal structures and the regional changes in airway volume were quantified. Changes in the most constricted area were also noted. Horizontal movements of D-point were significantly associated with increases in both total airway (403.6 ± 138.6 mm(3); P <0.01) and oropharynx (383.9 ± 127.9 mm(3); P <0.01) volumes. Vertical movements of the posterior nasal spine were significantly associated with decreases in total airway volume (-459.2 ± 219.9 mm(3); P = 0.04) and oropharynx volume (-639.7 ± 195.3 mm(3); P <0.01), increases in nasopharynx (187.2 ± 47.1 mm(3); P <0.01) volume, and decreases in the most constricted area (-10.63 ± 3.69 mm(2); P <0.01). In the Class III patients only, the vertical movement of D-point was significantly associated with decreases in both total airway (-724.0 ± 284.4 mm(3); P = 0.02) and oropharynx (-648.2 ± 270.4 mm(3); P = 0.02) volumes. A

  7. A method for accurate zero calibration of asymmetric jaws in single-isocenter half-beam techniques.

    PubMed

    Hernandez, V; Sempau, J; Abella, R; Lopez, M; Perez, M; Artigues, M; Arenas, M

    2013-02-01

    To present a practical method for calibrating the zero position of asymmetric jaws that provides higher accuracy at the central axis and improves dose homogeneity in the abutting region of half-beams. Junction doses were measured for each asymmetric jaw using the double-exposure technique and electronic portal imaging devices. The junction dose was determined as a function of jaw position. The shift in the zero jaw position (or in its corresponding potentiometer readout) required to correct for the measured junction dose could thus be obtained. The jaw calibration was then modified to introduce the calculated shift and therefore achieve an accurate zero position in order to provide a relative junction dose that was as close to zero as possible. All the asymmetric jaws from four medical linear accelerators were calibrated with the new calibration procedure. Measured relative junction doses at gantry 0° were reduced from a maximum of ±40% to a maximum of ±8% for all the jaws in the four considered accelerators. These results were valid for 6 MV and 18 MV photon beams and for any combination of asymmetric jaws set to zero. The calibration was stable over a long period of time; therefore, the need for recalibrating is seldom necessary. Accurate calibration of the zero position of the jaws is feasible in current medical linear accelerators. The proposed procedure is fast and it improves dose homogeneity at the junction of half-beams, thus, allowing a more accurate and safer use of these techniques.

  8. Chin development as a result of differential jaw growth.

    PubMed

    Marshall, Steven D; Low, Laura E; Holton, Nathan E; Franciscus, Robert G; Frazier, Mike; Qian, Fang; Mann, Kyle; Schneider, Galen; Scott, Jill E; Southard, Thomas E

    2011-04-01

    During facial growth, the maxilla and mandible translate downward and forward. Although the forward displacement of the maxilla is less than that of the mandible, the interarch relationship of the teeth in the sagittal view during growth remains essentially unchanged. Interdigitation is thought to provide a compensatory (tooth movement) mechanism for maintaining the pattern of occlusion during growth: the maxillary teeth move anteriorly relative to the maxilla while the mandibular teeth move posteriorly relative to the basilar mandible. The purpose of this study was to investigate the hypothesis that the human chin develops as a result of this process. Twenty-five untreated subjects from the Iowa Facial Growth Study with Class I normal occlusion were randomly selected based on availability of cephalograms at T1 (mean = 8.32 yr) and T2 (mean = 19.90 yr). Measurements of growth (T2 minus T1) parallel to the Frankfort horizontal (FH) for the maxilla, maxillary dentition, mandible, mandibular dentition, and pogonion (Pg) were made. Relative to Pg (a stable bony landmark), B-point moved posteriorly, on average 2.34 mm during growth, and bony chin development (B-point to Pg) increased concomitantly. Similarly, the mandibular and maxillary incisors moved posteriorly relative to Pg 2.53 mm and 2.76 mm, respectively. A-point, relative to Pg, moved posteriorly 4.47 mm during growth. Bony chin development during facial growth occurs, in part, from differential jaw growth and compensatory dentoalveolar movements. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  9. The Microbursts of 22 June 1982 in JAWS.

    NASA Astrophysics Data System (ADS)

    Hjelmfelt, M. R.

    1987-06-01

    On 22 June 1982 a line of storms developed in the Joint Airport Weather Studies (JAWS) network near Denver, Colorado, in response to interaction of boundary-layer convergence lines and wind-parallel lines of convection. These storms produced six microbursts and one microburst line. Single and multiple Doppler radar data and surface network data were used to describe the structure and lift cycle of the microburst outflows and to examine potential forcing mechanisms.The microburst outflows can be classified into three types: isolated, generally symmetric outflows; outflows embedded in strong low-level environmental flow which reveal their symmetric diverging outflow structure only when the mean flow is eliminated and the microburst line. Some of the microburst decayed by weakening; others grew to larger-scale, less intense outflows.All of the microbursts were associated with descending high-reflectivity cores, many of which showed evidence of convergence and associated reflectivity decreases below cloud base. Most of the microbursts exhibited some rotation aloft. However, the relationship between the location of rotation and the downdraft was variable. Well-developed rotation also tended to be short lived, and timing of the appearance of rotation during the microburst life cycle varied from case to case. Application of the downdraft model of Srivastava indicated that sufficient negative buoyancy could be produced by evaporation and precipitation loading to account for the magnitude of the observed microburst downdrafts. It is concluded that the microbursts on this day were predominantly driven by microphysical and related thermodynamic effects due to processes of precipitation loading and water phase change.

  10. Influence of the Lower Jaw Position on the Running Pattern

    PubMed Central

    Stief, Felix; Jonas, Alexander; Kovac, Andrej; Groneberg, David Alexander; Meurer, Andrea

    2015-01-01

    Introduction The effects of manipulated dental occlusion on body posture has been investigated quite often and discussed controversially in the literature. Far less attention has been paid to the influence of dental occlusion position on human movement. If human movement was analysed, it was mostly while walking and not while running. This study was therefore designed to identify the effect of lower jaw positions on running behaviour according to different dental occlusion positions. Methods Twenty healthy young recreational runners (mean age = 33.9±5.8 years) participated in this study. Kinematic data were collected using an eight-camera Vicon motion capture system (VICON Motion Systems, Oxford, UK). Subjects were consecutively prepared with four different dental occlusion conditions in random order and performed five running trials per test condition on a level walkway with their preferred running shoes. Vector based pattern recognition methods, in particular cluster analysis and support vector machines (SVM) were used for movement pattern identification. Results Subjects exhibited unique movement patterns leading to 18 clusters for the 20 subjects. No overall classification of the splint condition could be observed. Within individual subjects different running patterns could be identified for the four splint conditions. The splint conditions lead to a more symmetrical running pattern than the control condition. Discussion The influence of an occlusal splint on running pattern can be confirmed in this study. Wearing a splint increases the symmetry of the running pattern. A more symmetrical running pattern might help to reduce the risk of injuries or help in performance. The change of the movement pattern between the neutral condition and any of the three splint conditions was significant within subjects but not across subjects. Therefore the dental splint has a measureable influence on the running pattern of subjects, however subjects individuality has to be

  11. Ossifying fibroma vs fibrous dysplasia of the jaw: molecular and immunological characterization.

    PubMed

    Toyosawa, Satoru; Yuki, Michiko; Kishino, Mitsunobu; Ogawa, Yuzo; Ueda, Takafumi; Murakami, Shumei; Konishi, Eiichi; Iida, Seiji; Kogo, Mikihiko; Komori, Toshihisa; Tomita, Yasuhiko

    2007-03-01

    Ossifying fibroma and fibrous dysplasia of the jaw are maxillofacial fibro-osseous lesions that should be distinguished each other by a pathologist because they show distinct patterns of disease progression. However, both lesions often show similar histological and radiological features, making distinction between the two a diagnostic dilemma. In this study, we performed immunological and molecular analyses of five ossifying fibromas, four cases of extragnathic fibrous dysplasia, and five cases of gnathic fibrous dysplasia with typical histological and radiographic features. First, we examined the difference between fibrous dysplasia and ossifying fibroma in the expression of Runx2 (which determined osteogenic differentiation from mesenchymal stem cells) and other osteogenic markers. Fibroblastic cells in fibrous dysplasia and ossifying fibroma showed strong Runx2 expression in the nucleus. The bone matrices of both lesions showed similar expression patterns for all markers tested except for osteocalcin. Immunoreactivity for osteocalcin was strong throughout calcified regions in fibrous dysplasia, but weak in ossifying fibroma lesions. Second, we performed PCR analysis with peptide nucleic acid (PNA) for mutations at the Arg(201) codon of the alpha subunit of the stimulatory G protein gene (GNAS), which has reported to be a marker for extragnathic fibrous dysplasia. All nine cases of extragnathic or gnathic fibrous dysplasia were positive for this mutation. On the other hand, none of the five cases of ossifying fibroma showed the mutation. These findings indicate that although fibrous dysplasia and ossifying fibroma are similar disease entities, especially in the demonstration of the osteogenic lineage in stromal fibroblast-like cells, they show distinct differences that can be revealed by immunohistochemical detection of osteocalcin expression. Furthermore, PCR analysis with PNA for GNAS mutations at the Arg(201) codon is a useful method to differentiate between

  12. Bisphosphonate-related osteonecrosis of the jaw: model and diagnosis with cone beam computerized tomography.

    PubMed

    Barragan-Adjemian, C; Lausten, L; Ang, D B; Johnson, M; Katz, J; Bonewald, L F

    2009-01-01

    Intravenous bisphosphonate (BP) therapy has become the standard of care for the treatment of cancers that metastasize to bone. BPs are associated with osteonecrosis of alveolar bones, a condition known as osteonecrosis of the jaw (ONJ). The incidence or pathogenesis of ONJ is largely unknown. The lesions are characterized by areas of exposed necrotic bone that do not heal after 8 weeks in the absence of radiation to the head and neck. ONJ lesions have been recalcitrant to conventional therapies. Lesions in cancer patients treated with BPs develop in association with periodontal disease, tooth extraction and/or in association with increased mechanical force due to partial/complete dentures. We hypothesized that intravenous BPs in cancer patients impair normal bone remodeling, thereby increasing the incidence of osteonecrotic lesions and that these lesions can be detected using cone beam computerized tomography (CBCT). From CBCTs taken at the University of Missouri at Kansas City School of Dentistry, 26 subjects had a cancer diagnosis and were on BP therapy. From these 26 subjects, 18 presented visible, exposed necrotic bone. We observed both sclerotic and radiolucent lesions. Lesions could be detected and measured in reconstructed images where most were found to expand to large areas of the bone. We were able to identify necrotic bodies or 'involucrums' within the ONJ lesions, suggesting that this could be the mechanism for the formation of a clinically visible sequestrum. We propose that CBCT can potentially identify and follow the progression of both pre- and postclinical lesions in ONJ patients, allowing better diagnosis and assessment of disease status. Copyright 2008 S. Karger AG, Basel.

  13. Oral microbiota and host innate immune response in bisphosphonate-related osteonecrosis of the jaw

    PubMed Central

    Pushalkar, Smruti; Li, Xin; Kurago, Zoya; Ramanathapuram, Lalitha V; Matsumura, Satoko; Fleisher, Kenneth E; Glickman, Robert; Yan, Wenbo; Li, Yihong; Saxena, Deepak

    2014-01-01

    Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate (BP)-related osteonecrosis of the jaw (ONJ) or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bacteria, most of these difficult to cultivate and presents many clinical challenges. The purpose of this study was to characterize the bacterial diversity in BRONJ lesions and to determine host immune response. We examined tissue specimens from three cohorts (n=30); patients with periodontal disease without a history of BP therapy (Control, n=10), patients with periodontal disease having history of BP therapy but without ONJ (BP, n=5) and patients with BRONJ (BRONJ, n=15). Denaturing gradient gel electrophoresis of polymerase chain reaction (PCR)-amplified 16S rRNA gene fragments revealed less bacterial diversity in BRONJ than BP and Control cohorts. Sequence analysis detected six phyla with predominant affiliation to Firmicutes in BRONJ (71.6%), BP (70.3%) and Control (59.1%). Significant differences (P<0.05) in genera were observed, between Control/BP, Control/BRONJ and BP/BRONJ cohorts. Enzyme-linked immunosorbent assay (ELISA) results indicated that the levels of myeloperoxidase were significantly lower, whereas interleukin-6 and tumor necrosis factor-alpha levels were moderately elevated in BRONJ patients as compared to Controls. PCR array showed significant changes in BRONJ patients with downregulation of host genes, such as nucleotide-binding oligomerization domain containing protein 2, and cathepsin G, the key modulators for antibacterial response and upregulation of secretory leukocyte protease inhibitor, proteinase 3 and conserved helix–loop–helix ubiquitous kinase. The results suggest that colonization of unique bacterial communities coupled with deficient innate immune response is likely to impact the pathogenesis of ONJ. PMID:25105817

  14. Time to onset of bisphosphonate-related osteonecrosis of the jaws: a multicentre retrospective cohort study.

    PubMed

    Fung, Ppl; Bedogni, G; Bedogni, A; Petrie, A; Porter, S; Campisi, G; Bagan, J; Fusco, V; Saia, G; Acham, S; Musto, P; Petrucci, M T; Diz, P; Colella, G; Mignogna, M D; Pentenero, M; Arduino, P; Lodi, G; Maiorana, C; Manfredi, M; Hallberg, P; Wadelius, M; Takaoka, K; Leung, Y Y; Bonacina, R; Schiødt, M; Lakatos, P; Taylor, T; De Riu, G; Favini, G; Rogers, S N; Pirmohamed, M; Nicoletti, P; Fedele, S

    2017-05-01

    Osteonecrosis of the jaw (ONJ) is a potentially severe adverse effect of bisphosphonates (BP). Although the risk of ONJ increases with increasing duration of BP treatment, there are currently no reliable estimates of the ONJ time to onset (TTO). The objective of this study was to estimate the TTO and associated risk factors in BP-treated patients. Retrospective analysis of data from 22 secondary care centres in seven countries relevant to 349 patients who developed BP-related ONJ between 2004 and 2012. The median (95%CI) TTO was 6.0 years in patients treated with alendronate (n = 88) and 2.2 years in those treated with zoledronate (n = 218). Multivariable Cox regression showed that dentoalveolar surgery was inversely associated, and the use of antiangiogenics directly associated, with the TTO in patients with cancer treated with zoledronate. The incidence of ONJ increases with the duration of BP therapy, with notable differences observed with respect to BP type and potency, route of administration and underlying disease. When data are stratified by BP type, a time of 6.0 and 2.2 years of oral alendronate and intravenous zoledronate therapy, respectively, is required for 50% of patients to develop ONJ. After stratification by disease, a time of 5.3 and 2.2 years of BP therapy is required for 50% of patients with osteoporosis and cancer, respectively, to develop ONJ. These findings have significant implications for the design of future clinical studies and the development of risk-reduction strategies aimed at either assessing or modulating the risk of ONJ associated with BP. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Implementation and commissioning of an integrated micro-CT/RT system with computerized independent jaw collimation

    SciTech Connect

    Jensen, Michael D.; Hrinivich, W. Thomas; Jung, Jongho A.; Holdsworth, David W.; Drangova, Maria; Chen, Jeff; Wong, Eugene

    2013-08-15

    Purpose: To design, construct, and commission a set of computer-controlled motorized jaws for a micro-CT/RT system to perform conformal image-guided small animal radiotherapy.Methods: The authors designed and evaluated a system of custom-built motorized orthogonal jaws, which allows the delivery of off-axis rectangular fields on a GE eXplore CT 120 preclinical imaging system. The jaws in the x direction are independently driven, while the y-direction jaws are symmetric. All motors have backup encoders, verifying jaw positions. Mechanical performance of the jaws was characterized. Square beam profiles ranging from 2 × 2 to 60 × 60 mm{sup 2} were measured using EBT2 film in the center of a 70 × 70 × 22 mm{sup 3} solid water block. Similarly, absolute depth dose was measured in a solid water and EBT2 film stack 50 × 50 × 50 mm{sup 3}. A calibrated Farmer ion chamber in a 70 × 70 × 20 mm{sup 3} solid water block was used to measure the output of three field sizes: 50 × 50, 40 × 40, and 30 × 30 mm{sup 2}. Elliptical target plans were delivered to films to assess overall system performance. Respiratory-gated treatment was implemented on the system and initially proved using a simple sinusoidal motion phantom. All films were scanned on a flatbed scanner (Epson 1000XL) and converted to dose using a fitted calibration curve. A Monte Carlo beam model of the micro-CT with the jaws has been created using BEAMnrc for comparison with the measurements. An example image-guided partial lung irradiation in a rat is demonstrated.Results: The averaged random error of positioning each jaw is less than 0.1 mm. Relative output factors measured with the ion chamber agree with Monte Carlo simulations within 2%. Beam profiles and absolute depth dose curves measured from the films agree with simulations within measurement uncertainty. Respiratory-gated treatments applied to a phantom moving with a peak-to-peak amplitude of 5 mm showed improved beam penumbra (80%–20%) from 3.9 to

  16. Micrognathozoa: a new class with complicated jaws like those of Rotifera and Gnathostomulida.

    PubMed

    Kristensen, R M; Funch, P

    2000-10-01

    A new microscopic aschelminth-like animal, Limnognathia maerski nov. gen. et sp., is described from a cold spring at Disko Island, West Greenland, and assigned to Micrognathozoa nov. class. It has a complex of jaws in its pharynx, and the ultrastructure of the main jaws is similar to that of the jaws of advanced scleroperalian gnathostomulids. However, other jaw elements appear also to have characteristics of the trophi of Rotifera. Jaw-like structures are found in other protostome taxa as well-for instance, in proboscises of kalyptorhynch platyhelminths, in dorvilleid polychaetes and aplacophoran mollusks-but studies of their ultrastructure show that none of these jaws is homologous with jaws found in Gnathostomulida, Rotifera, and Micrognathozoa. The latter three groups have recently been joined into the monophylum Gnathifera Ahlrichs, 1995, an interpretation supported by the presence of jaw elements with cuticular rods with osmiophilic cores in all three groups. Such tubular structures are found in the fulcrum of all Rotifera and in several cuticular sclerites of both Gnathostomulida and Micrognathozoa. The gross morphology of the pharyngeal apparatus is similar in the three groups. It consists of a ventral pharyngeal bulb and a dorsal pharyngeal lumen. The absence of pharyngeal ciliation cannot be used as an autapomorphy in the ground pattern of the Gnathifera because the Micrognathozoa has the plesiomorphic alternative with a ciliated pharyngeal epithelium. The body of Limnognathia maerski nov. gen. et sp. consists of a head, thorax, and abdomen. The dorsal and lateral epidermis have plates formed by an intracellular matrix, as in Rotifera and Acanthocephala; however, the epidermis is not syncytial. The ventral epidermis lacks internal plates, but has a cuticular oral plate without ciliary structures. Two ventral rows of multiciliated cells form a locomotory organ. These ciliated cells resemble the ciliophores present in some interstitial annelids. An adhesive

  17. Zinc and mechanical prowess in the jaws of Nereis, a marine worm

    SciTech Connect

    Lichtenegger, Helga C.; Schoberl, Thomas; Ruokolainen, Janne T.; Cross, Julie O.; Heald, Steve M.; Birkedal, Henrik; Waite, J. Herbert; Stucky, Galen

    2003-08-05

    Higher animals typically rely on calcification to harden certain tissues such as bones and teeth. Some notable exceptions can be found in invertebrates: The fangs, teeth, and mandibles of diverse arthropod species have been reported to contain high levels of zinc. Considerable quantities of zinc also occur in the jaws of the marine polychaete worm Nereis sp. High copper levels in the polychaete worm Glycera dibranchiata recently were attributed to a copper-based biomineral reinforcing the jaws. In the present article, we attempt to unravel the role of zinc in Nereis limbata jaws, using a combination of position-resolved state-of-the-art techniques. It is shown that the local hardness and stiffness of the jaws correlate with the local zinc concentration, pointing toward a structural role for zinc. Zinc always is detected in tight correlation with chlorine, suggesting the presence of a zinc– chlorine compound. No crystalline inorganic phase was found, however, and results from x-ray absorption spectroscopy further exclude the presence of simple inorganic zinc– chlorine compounds in amorphous form. The correlation of local histidine levels in the protein matrix and zinc concentration leads us to hypothesize a direct coordination of zinc and chlorine to the protein. A comparison of the role of the transition metals zinc and copper in the jaws of two polychaete worm species Nereis and Glycera, respectively, is presented.

  18. Zinc and mechanical prowess in the jaws of Nereis, a marine worm

    SciTech Connect

    Lichtenegger, Helga C.; Schoberl, Thomas; Ruokolainen, Janne T.; Cross, Julie O.; Heald, Steve M.; Birkedal, Henrik; Waite, J. Herbert; Stucky, Galen

    2003-08-05

    Higher animals typically rely on calcification to harden certain tissues such as bones and teeth. Some notable exceptions can be found in invertebrates: The fangs, teeth, and mandibles of diverse arthropod species have been reported to contain high levels of zinc. Considerable quantities of zinc also occur in the jaws of the marine polychaete worm Nereis sp. High copper levels in the polychaete worm Glycera dibranchiata recently were attributed to a copper-based biomineral reinforcing the jaws. In the present article, we attempt to unravel the role of zinc in Nereis limbata jaws, using a combination of position-resolved state-of-the-art techniques. It is shown that the local hardness and stiffness of the jaws correlate with the local zinc concentration, pointing toward a structural role for zinc. Zinc always is detected in tight correlation with chlorine, suggesting the presence of a zinc-chlorine compound. No crystalline inorganic phase was found, however, and results from x-ray absorption spectroscopy further exclude the presence of simple inorganic zinc-chlorine compounds in amorphous form. The correlation of local histidine levels in the protein matrix and zinc concentration leads us to hypothesize a direct coordination of zinc and chlorine to the protein. A comparison of the role of the transition metals zinc and copper in the jaws of two polychaete worm species Nereis and Glycera, respectively, is presented.

  19. Association between CYP19A1 genotype and pubertal sagittal jaw growth

    PubMed Central

    He, Shushu; Hartsfield, James K.; Guo, Yujiao; Cao, Yang; Wang, Si; Chen, Song

    2016-01-01

    Introduction Sagittal jaw growth is influenced during puberty by a ratio of androgens and estrogens. The CYP19A1 (formerly CYP19) gene encodes the cytochrome P450 enzyme aromatase (estrogen synthetase), which converts testosterone to estrogen. Genetic variations including single nucleotide polymorphisms might regulate CYP19A1 gene expression or the function of the aromatase protein and thus influence sagittal jaw growth. Methods The annual sagittal jaw growth in 92 pubertal orthodontic patients was determined by using pretreatment and posttreatment cephalometric radiographs. Single nucleotide polymorphisms rs2470144 and rs2445761 were genotyped and haplotypes constructed. Associations between genotypes or haplotypes and the annual sagittal growth were estimated by using JMP (version 9.0; SAS Institute, Cary, NC). Results Two single nucleotide polymorphisms were significantly associated with average differences in annual sagittal jaw growth in boys. Haplotype analysis demonstrated that haplotypes Trs2470144Trs2445761 and Crs2470144Trs2445761 had significant effects on annual sagittal maxillary growth and on mandibular growth in boys. No association was found in girls. Conclusions A quantitative trait locus that influences male pubertal sagittal jaw growth might exist in the CYP19A1 gene, and single nucleotide polymorphisms rs2470144 and rs2445761 might be inside this quantitative trait locus or be linked to it. PMID:23116507

  20. Human jaw muscle strength and size in relation to limb muscle strength and size.

    PubMed

    Raadsheer, M C; Van Eijden, T M G J; Van Ginkel, F C; Prahl-Andersen, B

    2004-10-01

    The aim of the present study was to investigate to what extent general factors (e.g. genotype, hormones) and factors at the craniofacial level (e.g. craniofacial size, jaw muscle architecture) contribute to the size and strength of the jaw muscles. A strong relationship of jaw muscle size and strength with that of other muscles would argue for general influences, whereas a weak relationship would argue for craniofacial influences. In 121 adult individuals, moments of maximal bite force, arm flexion force and leg extension force were measured. In addition, thicknesses of jaw muscles, arm flexor muscles and leg extensor muscles were measured using ultrasound. Relationships were assessed by using a principal component analysis. In females, one component was found in which all force moments were represented. Bite force moment, however, loaded very low. In males, two components were found. One component loaded for arm flexion and leg extension moments, the other loaded for bite force moments. In both females and males, only one component was found for the muscle thicknesses in which all muscle groups loaded similarly. It was concluded that the size of the jaw muscles was significantly related to the size of the limb muscles, suggesting that they were both subject to the same general influences. Maximal voluntary bite force moments were not significantly related to the moments of the arm flexion and leg extension forces, suggesting that besides the general influence on the muscle size, variation in bite force moment was also influenced by local variables, such as craniofacial morphology.

  1. An antiarch placoderm shows that pelvic girdles arose at the root of jawed vertebrates

    PubMed Central

    Zhu, Min; Yu, Xiaobo; Choo, Brian; Wang, Junqing; Jia, Liantao

    2012-01-01

    Almost all gnathostomes or jawed vertebrates (including osteichthyans, chondrichthyans, ‘acanthodians’ and most placoderms) possess paired pectoral and pelvic fins. To date, it has generally been believed that antiarch placoderms (extinct armoured jawed fishes from the Silurian–Devonian periods) lacked pelvic fins. The putative absence of pelvic fins is a key character bearing on the monophyly or paraphyly of placoderms. It also has far-reaching implications for studying the sequence of origin of pelvic girdles versus that of movable jaws in the course of vertebrate evolution. Parayunnanolepis xitunensis represents the only example of a primitive antiarch with extensive post-thoracic preservation, and its original description has been cited as confirming the primitive lack of pelvic fins in early antiarchs. Here, we present a revised description of Parayunnanolepis and offer the first unambiguous evidence for the presence of pelvic girdles in antiarchs. As antiarchs are placed at the base of the gnathostome radiation in several recent studies, our finding shows that all jawed vertebrates (including antiarch placoderms) primitively possess both pectoral and pelvic fins and that the pelvic fins did not arise within gnathostomes at a point subsequent to the origin of jaws. PMID:22219394

  2. Relationship between jaw apparatus, feeding habit, and food source in oriental woodpeckers.

    PubMed

    Donatelli, Reginaldo José; Höfling, Elizabeth; Catalano, Ana Luiza C

    2014-04-01

    Associations among feeding habit, beak type, and food source in birds have been widely studied and are well known to exist. The relationship between feeding habit and jaw apparatus in birds has not attracted attention from ornithologists, perhaps because of the complexity of the skeletal morphology of the feeding system of birds. The goal of this study was to compare the jaw apparatus and foraging strategies of various Oriental species of the Picidae (Meiglyptini and Picini tribes) using a morphofunctional analysis of the skeletal structure of the jaw apparatus. This study showed that there are at least three types of jaw apparatus in these woodpeckers, as follows: 1) robust, developed, and complex; 2) complexity and development intermediate, as observed in Meiglyptes tristis and Dinopium spp., whose main foraging method involves gleaning, probing, and tapping; and 3) poorly developed, as observed in Picus miniaceus and Hemicircus concretus. The success of woodpeckers as a natural group is due not only to their feeding diversity, but also their ability to explore a wide range of different resources, as appropriate to their jaw apparatus.

  3. Myofiber turnover is used to retrofit frog jaw muscles during metamorphosis.

    PubMed

    Alley, K E

    1989-01-01

    Metamorphic reorganization of the head in anuran amphibians entails abrupt restructuring of the jaw complex as larval feeding structures are transformed into their adult configurations. In this morphometric study, light microscopy wa used to analyze the larval maturation and metamorphic transfiguration of the adductor jaw muscles in the leopard frog (Rana pipiens). Larval jaw muscles, first established during embryogenesis, continue to grow by fiber addition until prometamorphosis, stage XII. Thereafter, fiber number remains stable but additional muscle growth continues by hypertrophy of the individual fibers until metamorphic climax. During metamorphic stages XIX-XXIII, a complete involution of all larval myofibers occurs. Simultaneously, within the same muscle beds, a second wave of myogenesis produces myoblasts which are the precursors of adult jaw myofibers. New muscle fibers continue to be added to these muscles well after the completion of metamorphosis; however, the total duration of the postmetamorphic myogenic period has not been defined. These observations provide clear evidence that the entir population of primary myofibers used in larval oral activity disappears from the adductor muscle beds and is replaced by a second wave of myogenesis commencing during climax. These findings indicate that the adductor jaw muscles are prepared for adult feeding by a complicated cellular process that retrofits existing muscle beds with a completely new complement of myofibers.

  4. Projection and synaptic connectivity of trigeminal mesencephalic nucleus neurons controlling jaw reflexes.

    PubMed

    Yoshida, Atsushi; Moritani, Masayuki; Nagase, Yoshitaka; Bae, Yong Chul

    2017-01-01

    Neurons in the trigeminal mesencephalic nucleus (Vmes) receive deep sensation (proprioception) from jaw-closing muscle spindles and periodontal ligaments and project primarily to the jaw-closing motoneuron pool (jaw-closing nucleus) of the trigeminal motor nucleus and to the supratrigeminal nucleus. Numerous articles have described the morphology and physiology of the central projections of Vmes afferents originating from the muscle spindles and periodontal ligaments. However, no report has provided a detailed description of projection and synaptic connectivity, especially of single afferents, and their functional implications. In this review, we reanalyze data obtained by single intra-axonal recording and labeling of functionally identified Vmes muscle spindle afferents and periodontal ligament afferents and by electron microscopic observation of their projection features and synaptic organization of boutons, to compare the data for the jaw-closing nucleus and supratrigeminal nucleus. Our analysis shows that each Vmes afferent type has characteristic projection pattern and synaptic feature that may be important in jaw-reflex control.

  5. Kinematic and Diffusion Tensor Imaging Definition of Familial Marcus Gunn Jaw-Winking Synkinesis

    PubMed Central

    Conte, Antonella; Brancati, Francesco; Garaci, Francesco; Toschi, Nicola; Bologna, Matteo; Fabbrini, Giovanni; Falla, Marika; Dallapiccola, Bruno; Bollero, Patrizio; Floris, Roberto; Berardelli, Alfredo

    2012-01-01

    Background Marcus Gunn jaw-winking synkinesis (MGJWS) is characterized by eyelid ptosis, which disappears during jaw movement. Familial MGJWS is an extremely rare condition. Some authors suggested that MGJWS is due to neural misdirection in the brainstem whereas others suggested that aberrant reinnervation or ephapse may be responsible for synkinetic activity. Pathogenesis of this condition is therefore still unclear. Methodology/Principal Findings To investigate pathogenetic mechanism in familial MGJWS we performed neurophysiological (EMG, Blink Reflex, Recovery cycle of the R2 component of the blink reflex, Masseter inhibitory reflex, BAEPS and kinematic analysis) and neuroradiological (MRI, Diffusion Tensor Imaging) investigations in a member of a multigenerational family with autosomal dominant Marcus Gunn jaw-winking synkinesis (MGJWS). Kinematic analysis of eyelid and jaw movements disclosed a similar onset and offset of the eyelid and jaw in both the opening and closing phases. The excitability of brainstem circuits, as assessed by the blink reflex recovery cycle and recovery index, was normal. Diffusion Tensor Imaging revealed reduced fractional anisotropy within the midbrain tegmentum. Conclusions/Significance Kinematic and MRI findings point to a brainstem structural abnormality in our familial MGJWS patient thus supporting the hypothesis of a neural misdirection of trigeminal motor axons to the elevator palpebralis muscle. PMID:23284759

  6. The impact of a total hip replacement on jaw position, upper body posture and body sway.

    PubMed

    Ohlendorf, Daniela; Lehmann, Christoph; Heil, Daniel; Hörzer, Stefan; Kopp, Stefan

    2015-04-01

    The purpose of this study was to examine whether, and to what extent, a total hip replacement can influence the position and the movement of the jaw, the upper body posture and body sway. Twenty test subjects (6 females, 14 males) participated in this study pre- and post-total hip replacement, in addition to a healthy control group of 20 subjects (5 females, 15 males). The measurements were conducted by means of an ultrasound system to measure jaw condyle position and movement of the lower jaw, a three-dimensional back scan to analyze upper back posture, and a static and dynamic force plate to measure body sway. For statistical analysis the Wilcoxon-Matched-Pairs-Test or Man-Whitney-U-Test, including a Bonferroni-Holm correction, respectively, was used. After surgery, the mean values of the left and right jaw condyles of the test group moved posterior, and the left condyle position was located more caudally. There were no significant differences concerning the jaw position between the two groups. There was little change in upper body posture in both groups. The test group had a more anteriorly inclined thoracic spine and a less pronounced lumbar lordosis. During static body sway measurements, increased fluctuations in the test group after surgery could be seen. Differences between both groups in the pre- and post-surgical condition could be detected. These differences were more prominent when the measured body segments were more distally located with respect to the hip region.

  7. Motor control of jaw movements: An fMRI study of parafunctional clench and grind behavior.

    PubMed

    Wong, Donald; Dzemidzic, Mario; Talavage, Thomas M; Romito, Laura M; Byrd, Kenneth E

    2011-04-06

    Jaw-clenching and tooth-grinding associated with bruxism can contribute to abnormal tooth wear and pain in the masticatory system. Clench and tooth-grinding jaw-movement tasks were evaluated in a block-design fMRI study comparing a dental-control (DC) group with a tooth-grinding (TG) group. Group classification was made prior to imaging based upon self-reported parafunctional clench and grind behavior and clinical evidence of abnormal tooth wear. Group differences in brain activation patterns were found for each task compared to the resting baseline. The DC group showed a more widely distributed pattern; more extensive activity in the supplementary motor area (SMA) proper that extended into the pre-SMA; and, for clench, activity in the left inferior parietal lobule (IPL). The DC group activated more than the TG subjects the left IPL for clench, and pre-SMA for grind. Neither task elicited more activity in the TG than DC subjects. Our group findings suggest that jaw-movement tasks executed by the TG group elicited (1) more efficient brain activation pattern consistent with other studies that found less extensive activity with executing "over-learned" tasks; (2) "underactive" SMA activity that underlies reduced motor planning; (3) decreased inferior parietal activity that is associated with lesser motor-attentional demands. Thus orofacial parafunctional habits may influence brain circuits recruited for jaw movements, providing a possible basis for understanding involuntary jaw movements in bruxism and oral movement disorders in general.

  8. Jaw Rotation in Dysarthria Measured With a Single Electromagnetic Articulography Sensor.

    PubMed

    Berry, Jeff; Kolb, Andrew; Schroeder, James; Johnson, Michael T

    2017-06-22

    This study evaluated a novel method for characterizing jaw rotation using orientation data from a single electromagnetic articulography sensor. This method was optimized for clinical application, and a preliminary examination of clinical feasibility and value was undertaken. The computational adequacy of the single-sensor orientation method was evaluated through comparisons of jaw-rotation histories calculated from dual-sensor positional data for 16 typical talkers. The clinical feasibility and potential value of single-sensor jaw rotation were assessed through comparisons of 7 talkers with dysarthria and 19 typical talkers in connected speech. The single-sensor orientation method allowed faster and safer participant preparation, required lower data-acquisition costs, and generated less high-frequency artifact than the dual-sensor positional approach. All talkers with dysarthria, regardless of severity, demonstrated jaw-rotation histories with more numerous changes in movement direction and reduced smoothness compared with typical talkers. Results suggest that the single-sensor orientation method for calculating jaw rotation during speech is clinically feasible. Given the preliminary nature of this study and the small participant pool, the clinical value of such measures remains an open question. Further work must address the potential confound of reduced speaking rate on movement smoothness.

  9. Osteonecrosis of the Jaw in Patients Receiving Bone-Targeted Therapies: An Overview--Part I.

    PubMed

    Turner, Bruce; Drudge-Coates, Lawrence; Ali, Sacha; Pati, Jhumur; Nargund, Vinod; Ali, Enamul; Cheng, Leo; Wells, Paula

    2016-01-01

    Urologic patients receiving bone-targeted therapies are at risk of developing osteonecrosis of the jaw (ONJ). ONJ has historically been associated with bisphosphonate therapy. More recently, RANK-Ligand inhibitors (denosumab) have also been used to reduce the risk of skeletal-related events in patients who have advanced cancers with bone metastases. More than 65% of men with metastatic prostate cancer and nearly 75% of women with metastatic breast cancer are affected by bone metastases. The literature has described ONJ associated with bisphosphonate therapy as bisphosphonate-related osteonecrosis of the jaw (BRONJ). However, with evidence also linking the use of RANK-Ligand inhibitors with osteonecrosis of the jaw, we advocate use of the term "anti-bone resorption therapy-related osteonecrosis of the jaw" (ABRT-ONJ). The term "medication-related osteonecrosis of the jaw" (MRONJ) is now becoming more widespread. There is not a universally accepted definition of ABRT-ONJ, which may have hindered recognition and reporting of the condition. In Part I of this article, a review of current knowledge around the etiology of ABRT-ONJ and incidence data are provided. In Part II, we provide an audit of ONJ in a nurse consultant-led bone support clinic. In the article, we refer to zoledronic acid because this is the bisphosphonate of choice for use in men with prostate cancer in the United Kingdom.

  10. Evolution of the mammalian middle ear and jaw: adaptations and novel structures

    PubMed Central

    Anthwal, Neal; Joshi, Leena; Tucker, Abigail S

    2013-01-01

    Having three ossicles in the middle ear is one of the defining features of mammals. All reptiles and birds have only one middle ear ossicle, the stapes or columella. How these two additional ossicles came to reside and function in the middle ear of mammals has been studied for the last 200 years and represents one of the classic example of how structures can change during evolution to function in new and novel ways. From fossil data, comparative anatomy and developmental biology it is now clear that the two new bones in the mammalian middle ear, the malleus and incus, are homologous to the quadrate and articular, which form the articulation for the upper and lower jaws in non-mammalian jawed vertebrates. The incorporation of the primary jaw joint into the mammalian middle ear was only possible due to the evolution of a new way to articulate the upper and lower jaws, with the formation of the dentary-squamosal joint, or TMJ in humans. The evolution of the three-ossicle ear in mammals is thus intricately connected with the evolution of a novel jaw joint, the two structures evolving together to create the distinctive mammalian skull. PMID:22686855

  11. Involvement of NMDA receptors in the ventrolateral striatum of rats in apomorphine-induced jaw movements.

    PubMed

    Fujita, Satoshi; Kiguchi, Motori; Kobayashi, Masayuki; Koshikawa, Noriaki; Waddington, John L

    2010-03-31

    The role of NMDA receptors in the ventrolateral striatum to modulate dopamine receptor-mediated jaw movements was investigated in freely moving rats, using a magnetic sensor system combined with intracerebral microinjection of drugs. Apomorphine (1mg/kg i.v.) induced repetitive jaw movements that were reduced, in a dose-dependent manner, by bilateral microinjections of the NMDA receptor agonist NMDA (0.1 and 1mug/0.2mul bilaterally) into the ventrolateral striatum. Apomorphine-induced repetitive jaw movements were also reduced, in a dose-dependent manner, by bilateral microinjections of the NMDA receptor antagonists d-APV (0.01 and 0.1mug) or MK-801 (0.5 and 5mug). The inhibitory effect of NMDA (1mug) was reduced by co-administration of MK-801 (0.5mug). Microinjections of drugs into the ventrolateral striatum in the absence of apomorphine did not affect jaw movements. These results suggest that NMDA receptors in the ventrolateral striatum play an important modulatory role in the expression of dopamine receptor-mediated jaw movements. However, similar effects of NMDA and NMDA antagonists echo previous paradoxical findings and indicate that interactions between dopamine and NMDA receptors are complex and multifaceted. Cellular mechanism(s) may involve differential effects of NMDA agonism and antagonism on dopamine D1-like vs D2-like receptors and, possibly, on related GABAergic processes. Copyright 2010 Elsevier B.V. All rights reserved.

  12. Mastication-induced modulation of the jaw-opening reflex during different periods of mastication in awake rabbits.

    PubMed

    Mostafeezur, Rahman; Yamamura, Kensuke; Kurose, Masayuki; Yamada, Yoshiaki

    2009-02-13

    The present study aimed to determine if sensory inputs from the intraoral mechanoreceptors similarly contributed to regulating the activity of the jaw-opening muscles throughout the masticatory sequence. We also aimed to determine if sensory inputs from the chewing and non-chewing sides equally regulated the activity of the jaw-opening muscles. Electromyographic (EMG) activities of jaw muscles (digastric and masseter) and jaw movements were recorded in awake rabbits. The entire masticatory sequence was divided into preparatory, rhythmic-chewing and preswallow periods, based on jaw muscles activity and jaw movements. The jaw-opening reflex (JOR) was evoked by unilateral low-intensity stimulation of the inferior alveolar nerve (IAN) on either the chewing or non-chewing side. Amplitude of the JOR was assessed by measuring peak-to-peak EMG activity in the digastric muscle, and was compared among the masticatory periods and between the chewing and non-chewing sides. The JOR was strongly suppressed during the jaw-closing phase in the rhythmic-chewing and preswallow periods, but this effect was transiently attenuated during the late part of the jaw-opening phase in these periods. However, modulation of the JOR varied from strong suppression to weak facilitation during the preparatory period. The patterns of JOR modulation were similar on the chewing and non-chewing sides in all masticatory periods. The results suggest that the sensory inputs from the intraoral mechanoreceptors regulate the activity of the jaw-opening muscles differently during the preparatory period compared with the other masticatory periods. Sensory inputs from both the chewing and non-chewing sides similarly regulate the activity of the jaw-opening muscles.

  13. Effect of muscle relaxants on experimental jaw-muscle pain and jaw-stretch reflexes: a double-blind and placebo-controlled trial.

    PubMed

    Svensson, Peter; Wang, Kelun; Arendt-Nielsen, Lars

    2003-01-01

    A randomised, double-blind, placebo-controlled three-way cross-over study was performed to investigate the effect of two muscle relaxants (tolperisone hydrochloride and pridinol mesilate) on experimental jaw-muscle pain and jaw-stretch reflexes. Fifteen healthy men participated in three randomised sessions separated by at least 1 week. In each session 300 mg tolperisone, 8 mg pridinol mesilate or placebo was administered orally as a single dose. One hour after drug administration 0.3 ml hypertonic saline (5.8%) was injected into the right masseter to produce muscle pain. Subjects continuously rated their perceived pain intensity on an electronic 10-cm visual analogue scale (VAS). The pressure pain threshold (PPT) was measured and short-latency reflex responses were evoked in the pre-contracted (15% maximal voluntary contraction) masseter and temporalis muscles by a standardised stretch device (1 mm displacement, 10 ms ramp time) before (baseline), 1 h after medication (post-drug), during ongoing experimental muscle pain (pain-post-drug), and 15 min after pain had vanished (post-pain). Analysis of variance demonstrated significantly lower VAS peak pain scores (5.9 +/- 0.4 cm) after administration of tolperisone hydrochloride compared with pridinol mesilate (6.8 +/- 0.4 cm) and placebo (6.6 +/- 0.4 cm) (P=0.020). Administration of pridinol mesilate was associated with a significant decrease in PPTs compared with tolperisone hydrochloride and placebo (P=0.002) after medication, but not after experimental jaw-muscle pain. The normalised peak-to-peak amplitude of the stretch reflexes were not significantly influenced by the test medication (P=0.762), but were in all sessions significantly facilitated during ongoing experimental jaw-muscle pain (P=0.034). In conclusion, tolperisone hydrochloride provides a small, albeit significant reduction in the perceived intensity of experimental jaw-muscle pain whereas the present dose had no effect on the short-latency jaw

  14. Measurements of backscattered radiation from Therac-20 collimator and trimmer jaws into beam monitor chamber.

    PubMed

    Kubo, H; Lo, K K

    1989-01-01

    The field size dependent photon output is known to be influenced by the existence of backscattered radiation (BSR) generated in the collimator or trimmer jaws of a linear accelerator. This paper describes the results of measurements made to study the existence of such backscatter by simulating the geometry of the treatment head of a Therac-20 linear accelerator. The machine's monitor chamber, flattening filter, and collimator jaws were simulated by another real monitor chamber, a 1-cm thick lead sheet and 2.5-cm thick low-melting-point alloy divergent blocks, respectively. BSR from the simulated collimator jaws (SCJ) was measured with the simulated monitor chamber (SMC) as a function of the openings of the SCJ and as a function of distance between SMC and SCJ. The present results demonstrate the presence of BSR in an 18-MV photon beam from a Therac-20 linear accelerator.

  15. Measurements of backscattered radiation from Therac-20 collimator and trimmer jaws into beam monitor chamber

    SciTech Connect

    Kubo, H.; Lo, K.K.

    1989-03-01

    The field size dependent photon output is known to be influenced by the existence of backscattered radiation (BSR) generated in the collimator or trimmer jaws of a linear accelerator. This paper describes the results of measurements made to study the existence of such backscatter by simulating the geometry of the treatment head of a Therac-20 linear accelerator. The machine's monitor chamber, flattening filter, and collimator jaws were simulated by another real monitor chamber, a 1-cm thick lead sheet and 2.5-cm thick low-melting-point alloy divergent blocks, respectively. BSR from the simulated collimator jaws (SCJ) was measured with the simulated monitor chamber (SMC) as a function of the openings of the SCJ and as a function of distance between SMC and SCJ. The present results demonstrate the presence of BSR in an 18-MV photon beam from a Therac-20 linear accelerator.

  16. X-ray computed tomography library of shark anatomy and lower jaw surface models.

    PubMed

    Kamminga, Pepijn; De Bruin, Paul W; Geleijns, Jacob; Brazeau, Martin D

    2017-04-11

    The cranial diversity of sharks reflects disparate biomechanical adaptations to feeding. In order to be able to investigate and better understand the ecomorphology of extant shark feeding systems, we created a x-ray computed tomography (CT) library of shark cranial anatomy with three-dimensional (3D) lower jaw reconstructions. This is used to examine and quantify lower jaw disparity in extant shark species in a separate study. The library is divided in a dataset comprised of medical CT scans of 122 sharks (Selachimorpha, Chondrichthyes) representing 73 extant species, including digitized morphology of entire shark specimens. This CT dataset and additional data provided by other researchers was used to reconstruct a second dataset containing 3D models of the left lower jaw for 153 individuals representing 94 extant shark species. These datasets form an extensive anatomical record of shark skeletal anatomy, necessary for comparative morphological, biomechanical, ecological and phylogenetic studies.

  17. A 3D Interactive Model and Atlas of the Jaw Musculature of Alligator mississippiensis

    PubMed Central

    Holliday, Casey M.; Tsai, Henry P.; Skiljan, Rebecca J.; George, Ian D.; Pathan, Sami

    2013-01-01

    Modern imaging and dissemination methods enable morphologists to share complex, three-dimensional (3D) data in ways not previously possible. Here we present a 3D interactive model of the jaw musculature of the American Alligator (Alligator mississippiensis). Alligator and crocodylian jaw musculature is notoriously challenging to inspect and interpret because of the derived nature of the feeding apparatus. Using Iodine-contrast enhanced microCT imaging, a segmented model of jaw muscles, trigeminal nerve, brain and skull are presented as a cross-sectional atlas and 3D, interactive pdf of the rendered model. Modern 3D dissemination methods like this 3D Alligator hold great potential for morphologists to share anatomical information to scientists, educators, and the public in an easily downloadable format. PMID:23762228

  18. A 3D interactive model and atlas of the jaw musculature of Alligator mississippiensis.

    PubMed

    Holliday, Casey M; Tsai, Henry P; Skiljan, Rebecca J; George, Ian D; Pathan, Sami

    2013-01-01

    Modern imaging and dissemination methods enable morphologists to share complex, three-dimensional (3D) data in ways not previously possible. Here we present a 3D interactive model of the jaw musculature of the American Alligator (Alligator mississippiensis). Alligator and crocodylian jaw musculature is notoriously challenging to inspect and interpret because of the derived nature of the feeding apparatus. Using Iodine-contrast enhanced microCT imaging, a segmented model of jaw muscles, trigeminal nerve, brain and skull are presented as a cross-sectional atlas and 3D, interactive pdf of the rendered model. Modern 3D dissemination methods like this 3D Alligator hold great potential for morphologists to share anatomical information to scientists, educators, and the public in an easily downloadable format.

  19. Key Roles of the Downstream Mobile Jaw of Escherichia coli RNA Polymerase in Transcription Initiation

    PubMed Central

    Drennan, Amanda; Kraemer, Mark; Capp, Michael; Gries, Theodore; Ruff, Emily; Sheppard, Carol; Wigneshweraraj, Sivaramesh; Artsimovitch, Irina; Record, M. Thomas

    2012-01-01

    Differences in kinetics of transcription initiation by RNA polymerase (RNAP) at different promoters tailor the pattern of gene expression to cellular needs. After initial binding, large conformational changes occur in promoter DNA and RNAP to form initiation-capable complexes. To understand the mechanism and regulation of transcription initiation, the nature and sequence of these conformational changes must be determined. Escherichia coli RNAP uses binding free energy to unwind and separate 13 base pairs of λPR promoter DNA to form the unstable open intermediate I2, which rapidly converts to much more stable open complexes (I3, RPo). Conversion of I2 to RPo involves folding/assembly of several mobile RNAP domains on downstream duplex DNA. Here, we investigate effects of a 42-residue deletion in the mobile β’ jawJAW) and truncation of promoter DNA beyond +12 (DT+12) on the steps of initiation. We find that in stable ΔJAW open complexes the downstream boundary of hydroxyl radical protection shortens by 5–10 base pairs, as compared to wild-type (WT) complexes. Dissociation kinetics of open complexes formed with ΔJAW RNAP and/or DT+12 DNA resemble those deduced for the structurally-uncharacterized intermediate I3. Overall rate constants (ka) for promoter binding and DNA opening by ΔJAW RNAP are much smaller than for WT RNAP. Values of ka for WT RNAP with DT+12 and full-length λPR are similar, though contributions of binding and isomerization steps differ. Hence, the jaw plays major roles both early and late in RPo formation, while downstream DNA functions primarily as the assembly platform after DNA opening. PMID:23116321

  20. The relationship between the cranial base and jaw base in a Chinese population

    PubMed Central

    2014-01-01

    Introduction The cranial base plays an important role in determining how the mandible and maxilla relate to each other. This study assessed the relationship between the cranial base and jaw base in a Chinese population. Methods This study involved 83 subjects (male: 27; female: 56; age: 18.4 ± 4.2 SD years) from Hong Kong, who were classified into 3 sagittal discrepancy groups on the basis of their ANB angle. A cephalometric analysis of the angular and linear measurements of their cranial and jaw bases was carried out. The morphological characteristics of the cranial and jaw bases in the three groups were compared and assessments were made as to whether a relationship existed between the cranial base and the jaw base discrepancy. Results Significant differences were found in the cranial base angles of the three groups. Skeletal Class II cases presented with a larger NSBa, whereas skeletal Class III cases presented with a smaller NSBa (P < 0.001). In the linear measurement, skeletal Class III cases presented with a shorter NBa than skeletal Class I and II cases (P < 0.01). There was a correlation between the cranial base angle NSBa and the SNB for the whole sample, (r = -0.523, P < 0.001). Furthermore, correlations between SBaFH and Wits (r = -0.594, P < 0.001) and SBaFH and maxillary length (r = -0.616, P < 0.001) were more obvious in the skeletal Class III cases. Conclusions The cranial base appears to have a certain correlation with the jaw base relationship in a southern Chinese population. The correlation between cranial base and jaw base tends to be closer in skeletal Class III cases. PMID:25129070

  1. The relationship between the cranial base and jaw base in a Chinese population.

    PubMed

    Chin, Alice; Perry, Suzanne; Liao, Chongshan; Yang, Yanqi

    2014-08-16

    The cranial base plays an important role in determining how the mandible and maxilla relate to each other. This study assessed the relationship between the cranial base and jaw base in a Chinese population. This study involved 83 subjects (male: 27; female: 56; age: 18.4±4.2 SD years) from Hong Kong, who were classified into 3 sagittal discrepancy groups on the basis of their ANB angle. A cephalometric analysis of the angular and linear measurements of their cranial and jaw bases was carried out. The morphological characteristics of the cranial and jaw bases in the three groups were compared and assessments were made as to whether a relationship existed between the cranial base and the jaw base discrepancy. Significant differences were found in the cranial base angles of the three groups. Skeletal Class II cases presented with a larger NSBa, whereas skeletal Class III cases presented with a smaller NSBa (P<0.001). In the linear measurement, skeletal Class III cases presented with a shorter NBa than skeletal Class I and II cases (P<0.01). There was a correlation between the cranial base angle NSBa and the SNB for the whole sample, (r=-0.523, P<0.001). Furthermore, correlations between SBaFH and Wits (r=-0.594, P<0.001) and SBaFH and maxillary length (r=-0.616, P<0.001) were more obvious in the skeletal Class III cases. The cranial base appears to have a certain correlation with the jaw base relationship in a southern Chinese population. The correlation between cranial base and jaw base tends to be closer in skeletal Class III cases.

  2. Indications for jaw gape-related control of relative muscle activation in sequent chewing strokes.

    PubMed

    Pröschel, P A; Morneburg, T R

    2010-03-01

    Jaw muscle activity ratios in unilateral isometric biting differ from ratios of unilateral chewing but approach the latter if the jaw gape in biting is made as small as the minimum interocclusal distance (MID) of chewing. Especially, the masseter working/balancing side ratio (W/B-ratio) becomes as asymmetric as in chewing, because of reduction in balancing side (BS) masseter activity. This behaviour of ratios might reflect a 'chewing-specific' motor strategy induced when isometric biting is performed with a 'chewing-like' gape. If this hypothesis applies, activity ratios should be associated with MIDs of sequent chewing strokes in a similar manner as with incremented jaw gapes in isometric biting. To test this prediction, bilateral surface electromyograms of masseter and anterior temporalis muscles and incisor movements were recorded during unilateral chewing in 52 subjects. W/B-ratios of masseter and temporalis activities and temporalis/masseter-ratios on both sides were calculated. The ratios were related to MIDs of consecutive chewing cycles. Three of the four ratios were associated with masticatory MID in the same manner as with jaw gape in isometric biting. In particular with decreasing MID, the masseter W/B-ratio increased from 1.5 to 2.2 (P < 0.01). This increase in asymmetry was attributed to a stronger decrease in masseter activity on the BS than on the working side. We conclude that relative jaw muscle activation is associated with interocclusal distance in a similar way in isometric biting and in chewing. This analogy supports the idea of a common jaw gape-related neuromuscular strategy facilitated by afferent signalling of interocclusal distance.

  3. Management of tinnitus and jaw-muscle tenderness using an intraoral appliance and acupuncture.

    PubMed

    Ström, Dan; Behrenth, Erik; Ekman, Kristina; Johansson, Anders; Unell, Lennart; Carlsson, Gunnar E

    2013-01-01

    Associations between signs and symptoms from the masticatory system and tinnitus have been reported.The aim of the study was to evaluate the effect of intraoral splint therapy and acupuncture on jaw-muscle tenderness and tinnitus. The study comprised 45 patients (24 men, 21 women; mean age 48 +/- 12 years) with long-standing tinnitus (duration 6.5 +/- 5.9 years).The patients were referred from the audiology department at the University hospital in Orebro, Sweden, where a complete audiological survey was performed. Jaw muscles were palpated and the subjective tinnitus evaluated on a 100 mm scale (VAS) at baseline and after one year. All patients received stabilization (Michigan type) splints at start of treatment. After 6 months, nonresponders (n=25) were subjected to acupuncture (6 sessions with duration of 30 minutes). Standard statistical methods were used. All patients had tender jaw muscles at palpation. Patients reported a significant decrease of the intensity of tinnitus during the observation period (from 78 +/- 20 mm to 52 +/- 24 mm after one year; P < 0.001). Only 6 (13%) of the 45 patients did not report any improvement of their tinnitus.The number of jaw muscles tender to palpation also decreased significantly from 7.9 +/- 5.9 to 4.6 +/- 5.3; (P<0.001). In conclusion, all 45 patients with tinnitus had tenderjaw muscles. Intraoral splint therapy and acupuncture had a favorable effect on tinnitus and the jaw muscle symptoms. One year after the start of treatment, all but 6 of the 45 patients reported improvement of their tinnitus. Based on the results it is suggested that many tinnitus patients with jaw muscle tenderness can benefit by a treatment including intraoral splint and acupuncture.

  4. What is It? Difficult to Pigeon Hole Tremor: a Clinical–Pathological Study of a Man with Jaw Tremor

    PubMed Central

    Louis, Elan D.; Bain, Peter G.; Hallett, Mark; Jankovic, Joseph; Vonsattel, Jean-Paul G.

    2013-01-01

    Background The phenomenology of tremor is broad and its classification is complicated. Furthermore, the full range of tremor phenomenology with respect to specific neurological and neurodegenerative diseases has not been fully elaborated. Case Report This right-handed man had a chief complaint of jaw tremor, which began approximately 20 years prior to death at age 101 years. He had been diagnosed with essential tremor (ET) by a local doctor. His examination at age 100 years was notable for marked jaw tremor at rest in the absence of other clear features of parkinsonism, mild kinetic tremor of the hands and, in the last year of life, a score of 22/41 on a cognitive screen. A senior movement disorder neurologist raised doubt about the “ET” diagnosis. The history and videotaped examination were reviewed by three additional senior tremor experts, who raised a number of diagnostic possibilities. A complete postmortem examination was performed by a senior neuropathologist, and was notable for the presence of tufted astrocytes, AT8-labeled glial cytoplasmic inclusions, and globose neuronal tangles. These changes were widespread and definitive. A neuropathological diagnosis of progressive supranuclear palsy was assigned. Discussion This case presents with mixed and difficult to clinically classify tremor phenomenology and other neurological findings. The postmortem diagnosis was not predicted based on the clinical features, and it is possible that it does not account for all of the features. The case raises many interesting issues and provides a window into the complexity of the interpretation, nosology, and classification of tremor phenomenology. PMID:23864988

  5. Indirect Estimates of Jaw Muscle Tension in Children with Suspected Hypertonia, Children with Suspected Hypotonia, and Matched Controls

    ERIC Educational Resources Information Center

    Connaghan, Kathryn P.; Moore, Christopher A.

    2013-01-01

    Purpose: In this study, the authors compared indirect estimates of jaw-muscle tension in children with suspected muscle-tone abnormalities with age- and gender-matched controls. Method: Jaw movement and muscle activation were measured in children (ages 3 years, 11 months, to 10 years) with suspected muscle-tone abnormalities (Down syndrome or…

  6. Indirect Estimates of Jaw Muscle Tension in Children with Suspected Hypertonia, Children with Suspected Hypotonia, and Matched Controls

    ERIC Educational Resources Information Center

    Connaghan, Kathryn P.; Moore, Christopher A.

    2013-01-01

    Purpose: In this study, the authors compared indirect estimates of jaw-muscle tension in children with suspected muscle-tone abnormalities with age- and gender-matched controls. Method: Jaw movement and muscle activation were measured in children (ages 3 years, 11 months, to 10 years) with suspected muscle-tone abnormalities (Down syndrome or…

  7. The Frequency of Medication-related Osteonecrosis of the Jaw and its Associated Risk Factors.

    PubMed

    Dodson, Thomas B

    2015-11-01

    This article provides the best current frequency estimate of medication-related osteonecrosis of the jaws (MRONJ), and identifies factors associated with the risk of developing osteonecrosis of the jaw (ONJ) among patients exposed to relevant medications (ie, antiresorptive or antiangiogenic agents). MRONJ is a rare but serious complication of cancer treatment or osteoporosis management. This review confirms that antiresorptive medications such as oral or intravenous bisphosphonates and denosumab are the most common risk factors for developing ONJ. The risk of MRONJ is greater in patients with cancer than in those receiving antiresorptive treatments for osteoporosis by a factor of 10. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. [A new surgical method: lengthening of jaw bone by means of distraction technique].

    PubMed

    Nord, P G

    2001-05-30

    Callus distraction, or distraction osteogenesis as the method also is called, is a new surgical technique which makes it possible to create new bone by bone elongation. The method was originally used in orthopedic surgery to extend long bones but has subsequently proved useful for extending the mandible as well as other bones in the facial skeleton. By callus distraction, it is now possible to treat severe jaw anomalies and also to treat bone defects in the jaws without bone transplantation. This article describes the biological background to the method and the basic principles that must be observed for successful results. The treatment of four patients illustrates the method.

  9. Bisphosphonate-related osteonecrosis of the jaw complicated by Ludwig's angina.

    PubMed

    Yang, Rong-Hsin; Shen, Shu-Huei; Li, Wing-Yin; Chu, Yum-Kung

    2015-01-01

    Ludwig's angina is a life-threatening cellulitis that involves the submandibular and sublingual spaces. It often occurs after an infection of the roots of the teeth. However, modern dental care and use of antibiotics for oral infections have made Ludwig's angina rare. We present here a cancer patient exhibiting the sequential features of bisphosphonate related osteonecrosis of the jaw on bone scan complicating with Ludwig's angina. This report highlights the need for medical practitioners to be alert to these rare combinations in the compromised patient after bisphosphonate therapy. To the best of our knowledge, no case of Ludwig's angina secondary to osteonecrosis of the jaw has been reported.

  10. PERIAPICAL LESIONS OF THE JAWS: A REVIEW OF 104 CASES IN IBADAN

    PubMed Central

    Akinyamoju, AO; Gbadebo, SO; Adeyemi, BF

    2014-01-01

    Background: Periapical lesions (PLs) occur as a result of pulpal inflammation and may rarely be seen in the absence of pulpal diseases. They are the most common pathological lesions affecting the alveolar bone. Objective: This study aims to describe the clinicopathological features of PLs of the jaws with emphasis on the two most common types. Methods: Histopathology records of PLs diagnosed from January 1990 to December 2012 at the Department of Oral Pathology, University College Hospital Ibadan, were examined and categorized into periapical cysts (PCs); periapical granuloma (PGs) and others. Clinical data and histopathological features of these PLs were reviewed and analyzed. Results: One hundred and four lesions met the criteria for this study and consisted of PGs with 71 (68.3%) cases and PCs with 31 (29.8%) cases and one case each of apical scar and pleomorphic adenoma. Age range of cases was 9 to 80 years (mean=35.6 ± 15.8years) with a peak at age group of 20-29 years. Females were more frequently affected with 51.9% of cases. PLs were most frequently diagnosed in the anterior maxillary region with 58 (56.9%) cases, while the most frequently involved tooth was the left maxillary central incisor with 23 (22.1%) cases. Conclusion: Findings in this study are consistent with those of previous studies. It is important for all periapical pathological specimens to be submitted for histological examination to establish an accurate diagnosis and aid in the identification of sinister lesions that may present in the Periradicular region of teeth. PMID:25960702

  11. Increased Prevalence of Bisphosphonate-Related Osteonecrosis of the Jaw with Vitamin D Deficiency in Rats

    PubMed Central

    Hokugo, Akishige; Christensen, Russell; Chung, Evelyn M; Sung, Eric C; Felsenfeld, Alan L; Sayre, James W; Garrett, Neal; Adams, John S; Nishimura, Ichiro

    2010-01-01

    Necrotic bone exposure in the oral cavity has recently been reported in patients treated with nitrogen-containing bisphosphonates as part of their therapeutic regimen for multiple myeloma or metastatic cancers to bone. It has been postulated that systemic conditions associated with cancer patients combined with tooth extraction may increase the risk of osteonecrosis of the jaw (ONJ). The objective of this study was to establish an animal model of bisphosphonate-related ONJ by testing the combination of these risk factors. The generation of ONJ lesions in rats resembling human disease was achieved under the confluence of intravenous injection of zoledronate (ZOL; 35 µg/kg every 2 weeks), maxillary molar extraction, and vitamin D deficiency [VitD(−)]. The prevalence of ONJ in the VitD(−)/ZOL group was 66.7%, which was significantly higher (p < .05, Fisher exact test) than the control (0%), VitD(−) (0%), and ZOL alone (14.3%) groups. Similar to human patients, rat ONJ lesions prolonged the oral exposure of necrotic bone sequestra and were uniquely associated with pseudoepitheliomatous hyperplasia. The number of terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate–biotin nick-end label–positive (TUNEL+) osteoclasts significantly increased on the surface of post–tooth extraction alveolar bone of the VitD(−)/ZOL group, where sustained inflammation was depicted by [18F]fluorodeoxyglucose micro-positron emission tomography (µPET). ONJ lesions were found to be associated with dense accumulation of mixed inflammatory/immune cells. These cells, composed of neutrophils and lymphocytes, appeared to juxtapose apoptotic osteoclasts. It is suggested that the pathophysiologic mechanism(s) underpinning ONJ may involve the interaction between bisphosphonates and compromised vitamin D functions in the realm of skeletal homeostasis and innate immunity. © 2010 American Society for Bone and Mineral Research. PMID:20200938

  12. Dental extraction following zoledronate, induces osteonecrosis in rat´s jaw

    PubMed Central

    Gómez-Clavel, José-Francisco; Gaitán-Cepeda, Luis-Alberto

    2017-01-01

    Background Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) is clinically characterized by the presence of exposed bone in the oral cavity that persists for more than eight weeks. Previous attempts to establish an animal model have not sufficiently considered disease features. Our aim was to establish an inexpensive and replicable animal model that develops BRONJ in a short time. Material and Methods Thirty-two male Wistar rats were randomly divided into two groups: control and experimental. In the experimental group, we administered 0.06mg/kg intraperitoneal dose of zoledronic acid (ZA) 7 and 14 days prior to maxillary second molar extraction. At two, four and six weeks after tooth extraction, the animals were euthanized, and we dissected the maxilla following histological procedures. We stained serial slides with hematoxylin and eosin and Masson’s trichrome. The samples were harvested for macroscopic, radiologic and histological evaluation of bone changes. Results At two weeks postextraction, we observed exposed necrotic bone in dental socket areas in experimental groups. Radiological analysis revealed osteolytic lesions accompanied by extensive destruction and sequestrum formation in the same group. Histological examination confirmed the absence of necrotic bone in control groups in contrast with the experimental groups. The percentage of empty lacunae and the number of osteoclasts and the necrotic bone area were significantly increased (p<0.05) in the experimental groups. Conclusions The animal model using ZA administration to prior dental extraction successfully mimicked human BRONJ lesions. Also, the model was easily replicated, inexpensive and showed different features than other previous BRONJ models. Key words:Bisphosphonates, osteonecrosis, dental extractions, animal model, BRONJ. PMID:28160593

  13. Osteonecrosis of the jaws in 194 patients who have undergone intravenous bisphosphonate therapy in Spain.

    PubMed

    Vidal-Real, Carmen; Pérez-Sayáns, Mario; Suárez-Peñaranda, José-Manuel; Gándara-Rey, José-Manuel; García-García, Abel

    2015-05-01

    Osteonecrosis of the jaw (ONJ) is a destructive bone process in patients undergoing bisphosphonate therapy and it is modulated by local and systemic factors. The purpose of this article is to determine the prevalence of ONJ in patients who have undergone intravenous bisphosphonate therapy, and relate the risk factors described to establish a protocol to reduce the risk of developing ONJ. We performed a retrospective study on 194 patients treated with IV bisphosponates, analyzing clinical and pathological variables. The prevalence of ONJ was 12.9 %. The most remarkable complication was pain, which was reported by 80% of patients. The average age of the patients undergoing bisphosphonate therapy was 68.91 years. Most of non-diabetic patients did not develop ONJ (92.3%) (p=0.048). During bisphosphonate therapy, 3.1% of patients underwent extractions in the same percentage in the maxilla and in the mandible; all of which, except for one patient, developed ONJ (p<0.001). In regards to the periodontal state, 94.3% of patients without periodontal problems did not develop ONJ (p=0.001). Almost 50% of the necrosis were located unifocally on the mandible (p<0.001). The number of affected patients and the aggressiveness of the disease increased significantly three years after starting treatment (p<0.001). Etiology still is a controversial issue and we should focus on known risk factors, such as the development of surgical procedures in patients undergoing bisphosphonate therapy, especially in patients who have already started their treatment, a group in which ONJ prevalence increases. Moreover, a bad periodontal state in these patients is also an important risk factor, and the control of diabetes reduces it. Due to the above, all patients should be diagnosed and educated in oral hygiene prior to treatment, performing periodical maintenance, to detect possible traumatisms and periodontal infection as soon as possible.

  14. [Microstructure comparison of jaw sheaths between the Megophryid tadpoles (Amphibia, Anura) by the technology of electron microscope].

    PubMed

    Li, Cheng; Dong, Zhao-xiong; Wang, Yue-zhao

    2010-10-01

    The jaw sheaths morphology of eight megophryid larvae were examined using scanning electron microscope. The morphology of jaw sheaths of Leptobrachiinae and Leptolalaginae larvae was similar. Their jaw sheaths were U-shaped and strong keratinized, the serrations were pyramidal, with broad-based and short pointed. While the jaw sheaths of Megophryinae larvae were less curved and weak keratinized, the serrations were ivory-shaped, with narrow-based and long pointed. It has been found that the relationship between serration's diameter and density was negatively correlated, the changing trend reflected the functional significance of serrations. These distinctions among the jaw sheaths of tadpoles most could be related to their specific ecological habits and to their dietary specializations.

  15. Further structures in the jaw apparatus of Limnognathia maerski (Micrognathozoa), with notes on the phylogeny of the Gnathifera.

    PubMed

    Sørensen, Martin Vinther

    2003-02-01

    The jaws of Limnognathia maerski, Micrognathozoa, were investigated with light- and scanning electron microscopy. The study yielded several new structures and sclerites, including the ventral part of main jaw, the pharyngeal lamellae, the manus, the dorsal and ventral fibularium teeth, and a reinterpretation of the fibularium compartmentalization. Furthermore, it was shown that several jaw elements are composed of densely packed rods. Comparison with Rotifera and Gnathostomulida suggested that the micrognathozoan main jaw is homologous with the rotifer incus and the gnathostomulid articularium and that the pseudophalangids (the ventral jaws) and their associated sclerites correspond to the rotifer mallei. These results imply that Micrognathozoa is more closely related to Rotifera than to Gnathostomulida. Copyright 2002 Wiley-Liss, Inc.

  16. Metastatic breast cancer in the mandibular condyle mimicking temporomandibular joint (TMJ) disease

    PubMed Central

    Della Chiesa, Andrea; Scherrer, Beat; Kuttenberger, Johannes J.

    2014-01-01

    Metastases or tumour to the jaws are rare and those to the temporomandibular joint (TMJ) are even rarer. The symptoms like preauricular pain, swelling and clicking are generally associated with TMJ disease. But the same symptoms are also found in tumours of the jaws or other diseases. We report on the case of a 48-year-old woman with a 12-year history of breast cancer who was referred to our department for clarification of preauricular swelling and pain. The possible aetiology of TMJ disorders and the frequency and localization of metastases to the jaws are discussed. PMID:24876331

  17. Investigation of Pitch and Jaw Width to Decrease Delivery Time of Helical Tomotherapy Treatments for Head and Neck Cancer

    SciTech Connect

    Moldovan, Monica; Fontenot, Jonas D.; Gibbons, John P.; Lee, Tae Kyu; Rosen, Isaac I.; Fields, Robert S.; Hogstrom, Kenneth R.

    2011-01-01

    Helical tomotherapy plans using a combination of pitch and jaw width settings were developed for 3 patients previously treated for head and neck cancer. Three jaw widths (5, 2.5, and 1 cm) and 4 pitches (0.86, 0.43, 0.287, and 0.215) were used with a (maximum) modulation factor setting of 4. Twelve plans were generated for each patient using an identical optimization procedure (e.g., number of iterations, objective weights, and penalties, etc.), based on recommendations from TomoTherapy (Madison, WI). The plans were compared using isodose plots, dose volume histograms, dose homogeneity indexes, conformity indexes, radiobiological models, and treatment times. Smaller pitches and jaw widths showed better target dose homogeneity and sparing of normal tissue, as expected. However, the treatment time increased inversely proportional to the jaw width, resulting in delivery times of 24 {+-} 1.9 min for the 1-cm jaw width. Although treatment plans produced with the 2.5-cm jaw were dosimetrically superior to plans produced with the 5-cm jaw, subsequent calculations of tumor control probabilities and normal tissue complication probabilities suggest that these differences may not be radiobiologically meaningful. Because treatment plans produced with the 5-cm jaw can be delivered in approximately half the time of plans produced with the 2.5-cm jaw (5.1 {+-} 0.6 min vs. 9.5 {+-} 1.1 min), use of the 5-cm jaw in routine treatment planning may be a viable approach to decreasing treatment delivery times from helical tomotherapy units.

  18. Jaw-Opening Reflex and Corticobulbar Motor Excitability Changes During Quiet Sleep in Non-Human Primates

    PubMed Central

    Yao, Dongyuan; Lavigne, Gilles J.; Lee, Jye-Chang; Adachi, Kazunori; Sessle, Barry J.

    2013-01-01

    Study Objective: To test the hypothesis that the reflex and corticobulbar motor excitability of jaw muscles is reduced during sleep. Design: Polysomnographic recordings in the electrophysiological study. Setting: University sleep research laboratories. Participants and Interventions: The reflex and corticobulbar motor excitability of jaw muscles was determined during the quiet awake state (QW) and quiet sleep (QS) in monkeys (n = 4). Measurements and Results: During QS sleep, compared to QW periods, both tongue stimulation-evoked jaw-opening reflex peak and root mean square amplitudes were significantly decreased with stimulations at 2-3.5 × thresholds (P < 0.001). The jaw-opening reflex latency during sleep was also significantly longer than during QW. Intracortical microstimulation (ICMS) within the cortical masticatory area induced rhythmic jaw movements at a stable threshold (≤ 60 μA) during QW; but during QS, ICMS failed to induce any rhythmic jaw movements at the maximum ICMS intensity used, although sustained jaw-opening movements were evoked at significantly increased threshold (P < 0.001) in one of the monkeys. Similarly, during QW, ICMS within face primary motor cortex induced orofacial twitches at a stable threshold (≤ 35 μA), but the ICMS thresholds were elevated during QS. Soon after the animal awoke, rhythmic jaw movements and orofacial twitches could be evoked at thresholds similar to those before QS. Conclusions: The results suggest that the excitability of reflex and corticobulbar-evoked activity in the jaw motor system is depressed during QS. Citation: Yao D; Lavigne GJ; Lee JC; Adachi K; Sessle BJ. Jaw-opening reflex and corticobulbar motor excitability changes during quiet sleep in non-human primates. SLEEP 2013;36(2):269-280. PMID:23372275

  19. Investigation of pitch and jaw width to decrease delivery time of helical tomotherapy treatments for head and neck cancer.

    PubMed

    Moldovan, Monica; Fontenot, Jonas D; Gibbons, John P; Lee, Tae Kyu; Rosen, Isaac I; Fields, Robert S; Hogstrom, Kenneth R

    2011-01-01

    Helical tomotherapy plans using a combination of pitch and jaw width settings were developed for 3 patients previously treated for head and neck cancer. Three jaw widths (5, 2.5, and 1 cm) and 4 pitches (0.86, 0.43, 0.287, and 0.215) were used with a (maximum) modulation factor setting of 4. Twelve plans were generated for each patient using an identical optimization procedure (e.g., number of iterations, objective weights, and penalties, etc.), based on recommendations from TomoTherapy (Madison, WI). The plans were compared using isodose plots, dose volume histograms, dose homogeneity indexes, conformity indexes, radiobiological models, and treatment times. Smaller pitches and jaw widths showed better target dose homogeneity and sparing of normal tissue, as expected. However, the treatment time increased inversely proportional to the jaw width, resulting in delivery times of 24 ± 1.9 min for the 1-cm jaw width. Although treatment plans produced with the 2.5-cm jaw were dosimetrically superior to plans produced with the 5-cm jaw, subsequent calculations of tumor control probabilities and normal tissue complication probabilities suggest that these differences may not be radiobiologically meaningful. Because treatment plans produced with the 5-cm jaw can be delivered in approximately half the time of plans produced with the 2.5-cm jaw (5.1 ± 0.6 min vs. 9.5 ± 1.1 min), use of the 5-cm jaw in routine treatment planning may be a viable approach to decreasing treatment delivery times from helical tomotherapy units. Copyright © 2011 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  20. [Bone diseases].

    PubMed

    Uebelhart, Brigitte; Rizzoli, René

    2016-01-13

    Calcium intake shows a small impact on bone mineral density and fracture risk. Denosumab is a more potent inhibitor of bone resorption than zoledronate. Abaloparatide, PTHrP analog, increases bone mineral density and decreases fracture incidence. Teriparatide could be delivered via a transdermic device. Romosozumab and odanacatib improve calculated bone strength. Sequential or combined treatments with denosumab and teriparatide could be of interest, but not denosumab followed by teriparatide. Fibrous dysplasia, Paget disease and hypophosphatasia are updated, as well as atypical femoral fracture and osteonecrosis of the jaw.

  1. Impact of Actinomyces naeslundii on bisphosphonate-related osteonecrosis of the jaws in ovariectomized rats with periodontitis.

    PubMed

    Li, Chun Lei; Seneviratne, Chaminda Jayampath; Huo, Lei; Lu, Weijia William; Zheng, Li Wu

    2015-10-01

    Bisphosphonates-related osteonecrosis of the jaws (BRONJ) is a severe complication of BPs therapy with unknown pathogenesis. This study aimed to evaluate the impact of Actinomyces naeslundii (A. naeslundii) on the progression of BRONJ in ovariectomized (OVX) rat model with periodontal diseases. Sixty rats were randomly assigned into four groups. All rats underwent bilateral ovariectomy. Six weeks after surgery, animals with periodontitis induced by ligature placement were administrated with normal saline (NS), NS &A. naeslundii inoculation, zolecdronic acid (ZA) and ZA &A. naeslundii inoculation for 12 weeks, respectively. Loads of total bacteria and A. naeslundii in the mouth were assessed by real time PCR. After sacrifice, the mandibles were harvested for micro-computed tomography (micro-CT) and histological examination. Real-time PCR demonstrated that A. naeslundii was not routinely found in the rats and ZA treatment did not promote its accumulation. Micro-CT examination disclosed that ligature placement induced significant alveolar bone loss, which was greatly attenuated by ZA treatment and aggravated by A. naeslundii. Histological assessment demonstrated that ZA treatment increased the risk of developing BRONJ-like disease but this condition was not worsen with the presence of A. naeslundii. Our study suggested that oral A. naeslundii inoculation aggravated periodontal disease but not BRONJ in our animal model. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  2. Co-activation of jaw and neck muscles during submaximum clenching in the supine position.

    PubMed

    Giannakopoulos, N N; Schindler, H J; Rammelsberg, P; Eberhard, L; Schmitter, M; Hellmann, D

    2013-12-01

    The purpose of this study was to test the hypothesis that jaw clenching induces co-contraction and low-level long-lasting tonic activation (LLTA) of neck muscles in the supine position. Ten healthy subjects developed various feedback-controlled submaximum bite forces in different bite-force directions in supine position. The electromyographic (EMG) activity of the semispinalis capitis, semispinalis cervicis, multifidi, splenius capitis, levator scapulae, trapezius, sternocleidomastoideus, masseter and infra/supra-hyoidal muscles was recorded. For normalization of EMG data, maximum-effort tasks of the neck muscles were performed. Co-contractions of the posterior neck muscles varied between 2% and 11% of their maximum voluntary contraction. Different bite forces and bite-force directions resulted in significant (p<.05) activity differences between the co-contraction levels of the neck muscles. In addition, LLTA of specific neck muscles, provoked by the jaw clenching tasks, was observed. This study demonstrated for the first time moderate co-contractions of jaw and neck muscles in the supine position under controlled submaximum jaw clenching forces. LLTA of most neck muscles was observed, outlasting clenching episodes and indicating an additional neuromuscular interaction between the two muscle groups. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Bisphosphonates, vitamin D, parathyroid hormone, and osteonecrosis of the jaw. Could there be a missing link?

    PubMed Central

    Leizaola-Cardesa, Ignacio-Osoitz; Aguilar-Salvatierra, Antonio; Gonzalez-Jaranay, Maximino; Moreu, Gerardo; Sala-Romero, María-José

    2016-01-01

    It is estimated that over 190 million bisphosphonates have been prescribed worldwide. But this drug can produce adverse effects, of which osteonecrosis of the jaw and severe hypocalcemia are the most serious. It is evident that bisphosphonate administration affects multiple and diverse biochemical mediators related to bone metabolism. This review of literature investigates four basic parameters in patients treated with bisphosphonates - parathyroid hormone (PTH), bisphosphonates, vitamin D, calcium, and jaw osteonecrosis - which are fundamental for assessing bone metabolism and so the efficacy and correct use of the drug. The imbalances generated by vitamin D and calcium deficiencies, together with their multiple systemic repercussions, have been widely researched but the outcomes of these imbalances in relation to bisphosphonate administration are not well known, and some research has indicated that they may be associated with osteonecrosis of the jaw (ONJ). The present review set out to explain the functioning of bone metabolism, the importance of different chemical mediators, the imbalances produced by incorrect use of this drug, in order to forewarn against the possible relation of these parameters with ONJ, whose physiopathology remains unknown. Medical and dental clinics should keep detailed anamneses of the use of vitamin D and calcium supplements, as it is of vital importance to maintain their correct levels in blood, given that these are related to ONJ as well as other adverse effects; this procedure is also necessary in order to ensure the correct use of the drug. Key words:Bisphosphonate-related osteonecrosis of the jaw, vitamin D, parathyroid hor PMID:26827062

  4. Embryology of the lamprey and evolution of the vertebrate jaw: insights from molecular and developmental perspectives.

    PubMed Central

    Kuratani, S; Nobusada, Y; Horigome, N; Shigetani, Y

    2001-01-01

    Evolution of the vertebrate jaw has been reviewed and discussed based on the developmental pattern of the Japanese marine lamprey, Lampetra japonica. Though it never forms a jointed jaw apparatus, the L. japonica embryo exhibits the typical embryonic structure as well as the conserved regulatory gene expression patterns of vertebrates. The lamprey therefore shares the phylotype of vertebrates, the conserved embryonic pattern that appears at pharyngula stage, rather than representing an intermediate evolutionary state. Both gnathostomes and lampreys exhibit a tripartite configuration of the rostral-most crest-derived ectomesenchyme, each part occupying an anatomically equivalent site. Differentiated oral structure becomes apparent in post-pharyngula development. Due to the solid nasohypophyseal plate, the post-optic ectomesenchyme of the lamprey fails to grow rostromedially to form the medial nasal septum as in gnathostomes, but forms the upper lip instead. The gnathostome jaw may thus have arisen through a process of ontogenetic repatterning, in which a heterotopic shift of mesenchyme-epithelial relationships would have been involved. Further identification of shifts in tissue interaction and expression of regulatory genes are necessary to describe the evolution of the jaw fully from the standpoint of evolutionary developmental biology. PMID:11604127

  5. Jaw muscle functional anatomy in northern grasshopper mouse, Onychomys leucogaster, a carnivorous murid.

    PubMed

    Satoh, Kazuhiko; Iwaku, Fumihiko

    2006-08-01

    The jaw muscle anatomy of the northern grasshopper mouse, Onychomys leucogaster, was observed and the mechanical basis of the insectivorous/carnivorous adaptations were examined. Compared with Peromyscus maniculatus, a granivorous relative of Onychomys, there is a reduction of some aponeuroses within the masseter deep layer. This characteristic indicates that shearing meat or crushing arthropod exoskeletons requires less occlusal pressure than does grinding plant material. In Onychomys both the anterior and posterior portions of the masseter deep layer are more anterodorsally inclined, so that the line of action of the masseter lies further from the jaw joint than in Peromyscus. A strong incisal bite for killing vertebrates such as other rodents can be produced by a jaw mechanism with the high lever advantage of this muscle, which compensates for the decline in muscle mass. Our quantitative analysis suggests that the disappearance of an aponeurosis along the zygomatic plate in Onychomys decreases the stretch of the corresponding muscle, i.e., the anterior fibers of the masseter deep layer, accompanying jaw opening, and increases the maximum gape necessary for hunting large prey. Copyright 2006 Wiley-Liss, Inc.

  6. Effectiveness of jaw relaxation for burn dressing pain: randomized clinical trial.

    PubMed

    Rafii, Forough; Mohammadi-Fakhar, Fahimeh; Jamshidi Orak, Roohangiz

    2014-12-01

    Patients hospitalized for burn injuries experience severe pain, both immediately after the injury and during daily therapeutic procedures such as dressing changes. Relaxation is increasingly suggested as a pain control technique that can be used by nurses in daily practice. Yet the effects of relaxation on burn pain are not clear. The aim of this study was to investigate whether jaw relaxation will decrease pain intensity of burn dressing. Accordingly, a randomized clinical trial (n = 100) was conducted between 2009 and 2010 to compare jaw relaxation and usual care. Consenting patients were randomly assigned to either experimental or control groups using minimization. The experimental group practiced jaw relaxation for 20 minutes before entering the dressing room. Data were collected by visual analog scale (VAS), and several structured questions were asked of the experimental group. No significant difference was seen between mean pain intensity scores in the experimental and control groups after dressing (p = .676). Regarding the ineffectiveness of jaw relaxation for pain intensity of burn dressing, future studies are suggested to concentrate on longer durations of relaxation time and continuing the procedure in dressing room. Simultaneous study of the effect of this technique on residual, breakthrough, and procedural burn pain is also recommended. Copyright © 2014 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

  7. Jaw mechanism and dental function in the late cretaceous basal eusuchian Iharkutosuchus.

    PubMed

    Osi, Attila; Weishampel, David B

    2009-08-01

    Iharkutosuchus makadii is a basal eusuchian crocodylian with multicusped teeth discovered from the Upper Cretaceous of Hungary. Skull and dentition morphology indicates an active food processing for this crocodylian. First among crocodylians, a combination of different analyses, including cranial adductor muscle reconstruction, tooth wear pattern, and enamel microstructure studies, is applied here to support this hypothesis. Data provide unambiguous evidence for significant dental occlusion that was a result of a unique, transverse mandibular movement. Reconstruction of the jaw adductors demonstrates strong muscles responsible for slow but active jaw closure as the motor of transverse jaw movement; nevertheless muscles producing rapid jaw closure were reduced. Macrowear orientations show a dominantly transverse movement of the mandibles completed by a slight anteroposterior component. Along with quadrate morphology, macrowear further indicates that this motion was accomplished by alternate rotation of the mandibles about the quadrate condyles. Dental morphology and wear patterns suggest two types of power stroke: a slicing-crushing stroke associated dominantly with anterior tooth-food-tooth contact (with a low degree of transverse mandibular movement) during in the early stage of mastication, and a grinding stroke with significant posterior tooth-tooth contact and a dynamic transverse movement occurring later. The patterns of microwear show a diverse diet for Iharkutosuchus including both soft and hard items. This is also supported by the microstructure of the thick, wrinkled enamel built up mostly by poorly developed columnar units. Based on wear patterns, ontogenetic variation in feeding habits of Iharkutosuchus is also recognized.

  8. Jaw mobility changes in patients with upper aerodigestive tract cancer undergoing radiation therapy.

    PubMed

    Bragante, Karoline; Wienandts, Patrícia; Mozzini, Carolina; Pinto, Rosélie; da Motta, Neiro; Jotz, Geraldo

    2015-11-01

    Radiation therapy is a therapeutic modality widely used for treatment of upper aerodigestive tract (UADT) neoplasms. However, its action is not restricted to tumor cells, and it may cause a variety of adverse reactions, including reduced jaw mobility. A prospective cohort study was conducted to assess changes in jaw mobility in patients with UADT cancer undergoing radiation therapy. Fifty-six patients completed the study. The results showed a significant reduction in mouth opening (p<0.001), right lateral excursion (p=0.038) and left lateral excursion (p=0.035) of the jaw, a significant increase in the presence (p<0.001) and severity of oral mucositis (p<0.001), and a significant decrease in performance status (p<0.001) after radiation therapy. Thirty-six patients (64.3%) exhibited reduction in mouth opening after treatment. The variables significantly associated with mouth opening reduction on bivariate analysis were: modification of diet (p=0.037), radiation field (p=0.024), presence of mucositis (p=0.003), and reduction in performance status (p=0.007). After adjustment by the multivariate model, the only variables that remained significantly associated with reduction in mouth opening were presence of mucositis (p=0.018) and reduction in performance status (p=0.47). These findings indicate that patients with upper aerodigestive tract cancer experience reduced jaw mobility after radiation therapy, which is strongly correlated with mucositis and reduced functional ability.

  9. Osteosarcoma of the jaws: a review of literature and a case report on synchronous multicentric osteosarcomas.

    PubMed

    Nthumba, Peter M

    2012-11-12

    In the head and neck region, osteosarcoma is the most common primary malignant bone tumor, representing 23% of total head and neck malignancies. Osteosarcomas of the jaws are nevertheless rare lesions, representing only 2 to 10% of all osteosarcomas. This report reviews a single-center histopathology experience with craniofacial osteosarcomas, and reports the management of unusually large synchronous mandibular and maxillary osteosarcomas in a patient. A search of the hospital pathology database for specimens with a histological diagnosis of osteosarcomas submitted between July 1992 and May 2011 was made. A chart review of a patient with large synchronous maxillary and mandibular osteosarcomas was performed, and is reported. A 21-year-old African man with large maxillary and mandibular tumors under palliative care presented with increasing difficulties with eating, speech, and breathing. Surgical debulking was performed, with histology confirming synchronous osteosarcomas of the mandible and maxilla. The patient is well after one year, with no evidence of recurrence, having undergone no further treatment. Osteosarcomas of the jaw remain enigmatic, and a number of difficulties related to their diagnosis and treatment are yet to be resolved. True synchronous multicentric osteosarcomas of the jaws are extremely rare but, like other osteosarcomas of the jaws, have a favorable outcome, and palliative resection of such lesions, though challenging, can therefore lead to an enormously improved quality of life and self-image, and may even offer the opportunity for cure.

  10. Annual reversible plasticity of feeding structures: cyclical changes of jaw allometry in a sea urchin.

    PubMed

    Ebert, Thomas A; Hernández, José Carlos; Clemente, Sabrina

    2014-03-22

    A wide variety of organisms show morphologically plastic responses to environmental stressors but in general these changes are not reversible. Though less common, reversible morphological structures are shown by a range of species in response to changes in predators, competitors or food. Theoretical analysis indicates that reversible plasticity increases fitness if organisms are long-lived relative to the frequency of changes in the stressor and morphological changes are rapid. Many sea urchin species show differences in the sizes of jaws (demi-pyramids) of the feeding apparatus, Aristotle's lantern, relative to overall body size, and these differences have been correlated with available food. The question addressed here is whether reversible changes of relative jaw size occur in the field as available food changes with season. Monthly samples of the North American Pacific coast sea urchin Strongylocentrotus purpuratus were collected from Gregory Point on the Oregon (USA) coast and showed an annual cycle of relative jaw size together with a linear trend from 2007 to 2009. Strongylocentrotus purpuratus is a long-lived species and under field conditions individuals experience multiple episodes of changes in food resources both seasonally and from year to year. Their rapid and reversible jaw plasticity fits well with theoretical expectations.

  11. Re-regeneration of lower jaws and the dental lamina in adult urodeles.

    PubMed

    Graver, H T

    1978-09-01

    Transverse amputations were carried out through one-third fully regenerated jaw segments and through normal tissue of the mandible on the same and opposite sides of the jaw in adults of Notophthalmus viridescens. Collectively the results suggest that, in adult urodeles, the mandible and the dental lamina can be replaced in an identical manner more than one time. Although the major histological events are the same in jaw regeneration and re-regeneration, regrowth is more rapid in re-regeneration. It appears that recently differentiated tissues of the regenerate have a higher capacity for regeneration than normal tissues amputated for the first time. Re-regeneration of the jaw occurs by growth of the original regenerate cartilage which has undergone reorganization. In re-regeneration, the skeletal elements exhibit no polarity and regrowth occurs in both directions, while the dental lamina possesses an anterior-posterior polarity and can regrow in an anterior direction only. Information concerning the mechanisms involved in the regenerative events remain to be determined.

  12. Annual reversible plasticity of feeding structures: cyclical changes of jaw allometry in a sea urchin

    PubMed Central

    Ebert, Thomas A.; Hernández, José Carlos; Clemente, Sabrina

    2014-01-01

    A wide variety of organisms show morphologically plastic responses to environmental stressors but in general these changes are not reversible. Though less common, reversible morphological structures are shown by a range of species in response to changes in predators, competitors or food. Theoretical analysis indicates that reversible plasticity increases fitness if organisms are long-lived relative to the frequency of changes in the stressor and morphological changes are rapid. Many sea urchin species show differences in the sizes of jaws (demi-pyramids) of the feeding apparatus, Aristotle's lantern, relative to overall body size, and these differences have been correlated with available food. The question addressed here is whether reversible changes of relative jaw size occur in the field as available food changes with season. Monthly samples of the North American Pacific coast sea urchin Strongylocentrotus purpuratus were collected from Gregory Point on the Oregon (USA) coast and showed an annual cycle of relative jaw size together with a linear trend from 2007 to 2009. Strongylocentrotus purpuratus is a long-lived species and under field conditions individuals experience multiple episodes of changes in food resources both seasonally and from year to year. Their rapid and reversible jaw plasticity fits well with theoretical expectations. PMID:24500161

  13. Local electrical stimulation: effective needling points for suppressing jaw opening reflex in rat.

    PubMed

    Toda, K; Suda, H; Ichioka, M; Iriki, A

    1980-10-01

    Effects of electroacupuncture on the jaw opening reflex after tooth pulp stimulation were investigated in lightly anesthetized rats. Electroacupuncture stimulation (45 Hz, 5 msec) was delivered to 8 meridian points and 6 nonmeridian ones for 15 min so as to compare the degree of suppression elicited from each point. Significant suppressive effects on the reflex were observed in the cases of Yin-Hsiang, Ho-Ku and Shou-Sanli stimulation and these effects were antagonized by naloxone. However, stimulation of Hsia-Kuan, Chu-Chih, Neiting and Taichi, although these points were reported to suppress oro-facial or dental pain in man, scarcely produced suppressive effects. On the other hand, stimulation of some nonmeridian points produced moderate analgesic effects as gauged by the jaw opening reflex. The present study revealed that specificity of the meridian points is not absolute, but relative and that Yin-Hsiang, Ho-Ku and Shou-Sanli points were fairly effective in suppressing pulp-evoked jaw opening reflex in rat, which is presumably a noxious reflex. When the jaw opening reflex was evoked by non-pulpal stimulation, electroacupuncture was less effective on the reflex.

  14. Effect of antiresorptive drugs on bony turnover in the jaw: denosumab compared with bisphosphonates.

    PubMed

    Ristow, Oliver; Gerngroß, Carlos; Schwaiger, Markus; Hohlweg-Majert, Bettina; Kehl, Victoria; Jansen, Heike; Hahnefeld, Lilian; Koerdt, Steffen; Otto, Sven; Pautke, Christoph

    2014-04-01

    Osteonecrosis of the jaw as a result of treatment with receptor activators of nuclear factor kappa-B ligand (RANKL) inhibitors (denosumab) is a new type of bony necrosis, the exact pathogenesis of which is unknown. Our aim was to find out whether the turnover of bone in the jaw is increased after denosumab has been given compared with other skeletal sites, and if that turnover might have a role in denosumab-related osteonecrosis of the jaw (DRONJ). Bone scintigraphic images of 45 female patients with breast cancer and bone metastases were analysed retrospectively, and divided into 3 groups: those given denosumab, those given a bisphosphonate, and a control group (n=15 in each). All patients had bone scintigraphy before treatment (T0) and during the course of treatment after 12 (T1) and 24 (T2) months. The data were analysed quantitatively using 6 preset bony regions of interest. There was similar turnover of bone in the mandible compared with other skeletal sites (such as the femur), while the maxilla showed significantly higher turnover. None of the bony regions investigated showed any significant changes after the bisphosphonate had been given. There was a tendency to increase bone turnover in those patients taking denosumab. The bone turnover of the jawbone is not overtly changed either by a bisphosphonate or denosumab, so it seems unlikely that oversuppression of bony turnover in the jawbones plays an important part either in the pathogenesis of DRONJ or in the bisphosphonate-related osteonecrosis of the jaw (BRONJ).

  15. Malagasy cichlids differentially limit impacts of body shape evolution on oral jaw functional morphology.

    PubMed

    Martinez, Christopher M; Sparks, John S

    2017-09-01

    Patterns of trait covariation, such as integration and modularity, are vital factors that influence the evolution of vertebrate body plans. In functional systems, decoupling of morphological modules buffers functional change in one trait by reducing correlated variation with another. However, for complex morphologies with many-to-one mapping of form to function (MTOM), resistance to functional change may also be achieved by constraining morphological variation within a functionally stable region of morphospace. For this research, we used geometric morphometrics to evaluate the evolution of body shape and its relationship with jaw functional morphology in two independent radiations of endemic Malagasy cichlid (Teleostei: Cichlidae). Our results suggested that the two subfamilies used different strategies to mitigate impacts of body shape variation on a metric of jaw function, maxillary kinematic transmission (MKT): (1) modularity between cranial and postcranial morphologies, and (2) integration of body and jaw evolution, with jaw morphologies varying in a manner that limits change in MKT. This research shows that, unlike modularity, MTOM allows traits to retain strong evolutionary covariation while still reducing impacts on functionality. These results suggest that MTOM, and its influence on the evolution of correlated traits, is likely much more widespread than is currently understood. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  16. Stress analysis during jaw movement based on vivo computed tomography images from patients with temporomandibular disorders.

    PubMed

    Cheng, H-Y; Peng, P-W; Lin, Y-J; Chang, S-T; Pan, Y-N; Lee, S-C; Ou, K-L; Hsu, W-C

    2013-03-01

    The purpose of this study is to develop three-dimensional (3D) finite element models of temporomandibular joints (TMJs) and to investigate stress distributions. To determine the causes of temporomandibular disorders (TMDs), the magnitude and location of the maximum stresses under physiological loading must be considered. Stress analysis TMD models were reconstructed from computed tomography (CT) data. Several studies have investigated finite element TMJ models, but few have used a bilateral mandible model that includes jaw closing and maximum opening. In this study, the authors defined an asymmetry index for the different stress values on each side joint; this index has not yet been investigated. According to clinical observation, one joint affects the other side joint during mastication. Three symptom-free volunteers and three symptomatic patients were selected as the control group (CG) and TMD group (TG), respectively. For the TG, data analysis indicated that the condyle was asymmetrical during jaw closing, while both the condyle and disc were slightly asymmetrical during jaw opening. The maximum stresses did not significantly differ between the CG and TG for either closing or opening of the jaw. The results of this study have a potential clinical benefit in terms of proving superior biomechanical behaviour. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  17. Implant assisted ortho-surgery in edentulous jaws: a clinical report

    PubMed Central

    Khojasteh, Arash; Payaminia, Leila; Alikhasi, Marzieh

    2015-01-01

    Key Clinical Message The severely atrophy of jaws often complicates ideally oral reconstruction of esthetics and functionality, and necessitates different preprosthetic surgeries including bone grafting, ortho-surgery, and implant insertion. The mentioned procedures could be done within different approaches. This report describes the management of an edentulous case by implant insertion before orthognathic correction. PMID:26576273

  18. Preliminary study of tissue-engineered odontogenesis in the canine jaw.

    PubMed

    Honda, Masaki J; Ohara, Takayuki; Sumita, Yoshinori; Ogaeri, Takunori; Kagami, Hideaki; Ueda, Minoru

    2006-02-01

    We previously reported a method for the development of tissue-engineered tooth. However, 1 drawback of the procedure was the inability to determine whether the tooth would function when transplanted in the jaw because it was formed in the omentum of the abdomen. Therefore, the present study was designed to evaluate whether transplantation of dissociated odontogenic cells could induce tissue-engineered odontogenesis in the canine jaw. Cells were harvested from canine first molar tooth buds and the resulting heterogeneous cell population was seeded on a biodegradable polymer. These constructs were then transplanted into the same sockets after extracting the tooth buds. After transplantation, we evaluated the transplanted constructs using dental x-ray, micro-computed tomography, histology, and immunohistochemistry. After 24 weeks, micro-x-ray computed tomography showed regenerated hard tissues in the jaw, and hematoxylin and eosin staining showed tubular dentin and bone. In the regenerated tissue, osteopontin, osteonectin, and osteocalcin antibodies stained the dentinal matrix. However, enamel tissue and dental-root formation were not observed. These data show for the first time the formation of dentin and bone from dissociated odontogenic cells in the canine jaw.

  19. Adaptive phenotypic plasticity in the Midas cichlid fish pharyngeal jaw and its relevance in adaptive radiation

    PubMed Central

    2011-01-01

    Background Phenotypic evolution and its role in the diversification of organisms is a central topic in evolutionary biology. A neglected factor during the modern evolutionary synthesis, adaptive phenotypic plasticity, more recently attracted the attention of many evolutionary biologists and is now recognized as an important ingredient in both population persistence and diversification. The traits and directions in which an ancestral source population displays phenotypic plasticity might partly determine the trajectories in morphospace, which are accessible for an adaptive radiation, starting from the colonization of a novel environment. In the case of repeated colonizations of similar environments from the same source population this "flexible stem" hypothesis predicts similar phenotypes to arise in repeated subsequent radiations. The Midas Cichlid (Amphilophus spp.) in Nicaragua has radiated in parallel in several crater-lakes seeded by populations originating from the Nicaraguan Great Lakes. Here, we tested phenotypic plasticity in the pharyngeal jaw of Midas Cichlids. The pharyngeal jaw apparatus of cichlids, a second set of jaws functionally decoupled from the oral ones, is known to mediate ecological specialization and often differs strongly between sister-species. Results We performed a common garden experiment raising three groups of Midas cichlids on food differing in hardness and calcium content. Analyzing the lower pharyngeal jaw-bones we find significant differences between diet groups qualitatively resembling the differences found between specialized species. Observed differences in pharyngeal jaw expression between groups were attributable to the diet's mechanical resistance, whereas surplus calcium in the diet was not found to be of importance. Conclusions The pharyngeal jaw apparatus of Midas Cichlids can be expressed plastically if stimulated mechanically during feeding. Since this trait is commonly differentiated - among other traits - between

  20. Internal kinematics of the tongue in relation to muscle activity and jaw movement in the pig.

    PubMed

    Liu, Z-J; Shcherbatyy, V; Kayalioglu, M; Seifi, A

    2009-09-01

    To explore the coordinative characteristics of tongue deformation, muscle activity and jaw movement during feeding, six ultrasonic crystals were implanted into the tongue body of ten 12-week-old Yucatan minipigs 1 week before the recording. These crystals formed a wedge-shaped configuration to allow recording dimensional changes in lengths, anterior and posterior widths and posterior thicknesses of the tongue body during feeding. Wire electromyographic activities (EMG) of superior and inferior longitudinalis, verticalis/transversus, genioglossus, styloglossus, masseter and digastricus and jaw movements were recorded simultaneously. Signals from these three sources were synchronized for real-time analyses. The results indicate: (i) dimensional changes were stereotypical in relation to each cycle of all three feeding behaviours; (ii) during chewing, expansion of tongue widths mainly occurred in the occlusal phase of jaw movement and was less coupled with the activity of tongue muscles, but the expansions of length and thickness were seen in the opening and closing phases and were better coupled with the activity of tongue muscles (P < 0.05); (iii) ingestion was characterized by the two-phased jaw opening, early expansion of anterior width prior to the occlusal phase and strong associations between tongue deformation and muscle activity; (iv) during drinking, the duration of the opening and closing phases was significantly prolonged (P < 0.01), the durations of tongue widening and lengthening were significantly shortened (P < 0.05) and anterior widening was predominant in the opening rather than in the closing or occlusal phases as compared with chewing and ingestion; and (v) the intrinsic tongue muscles did not show more or stronger correlations with the tongue deformation than did the extrinsic tongue muscles. These results suggest that (i) regional widening, lengthening and thickening of the tongue body occurs sequentially in relation to jaw movement phases, but

  1. Adaptive evolution of the lower jaw dentition in Mexican tetra (Astyanax mexicanus)

    PubMed Central

    2013-01-01

    Background The Mexican tetra (Astyanax mexicanus) has emerged as a good animal model to study the constructive and regressive changes associated with living in cave environments, as both the ancestral sighted morph and the cave dwelling morph are extant. The cave dwelling morphs lack eyes and body pigmentation, but have well developed oral and sensory systems that are essential for survival in dark environments. The cave forms and surface forms are interfertile and give rise to F1 hybrids progeny known as intermediates. In cavefish, degeneration of the lens is one of the key events leading to eye regression. We have previously shown that surgical lens removal in surface fish embryos has an effect on the craniofacial skeleton. Surprisingly, lens removal was also found to have an effect on the caudal teeth in the lower jaw. In order to understand this result, we analyzed the lower jaw and upper jaw dentitions of surface, cavefish and F1 hybrids of surface and cavefish and compared our findings with surface fish that underwent lens removal. We also investigated the upper jaw (premaxillae and maxillae) dentition in these fish. Results Our tooth analyses shows that cavefish have the highest numbers of teeth in the mandible and maxillae, surface forms have the lowest numbers and F1 hybrids are between these groups. These differences are not observed in the premaxillae. A wide diversity of cuspal morphology can also be found in these fish. Jaw size also differs amongst the groups, with the mandible exhibiting the greatest differences. Interestingly, tooth number in surgery fish is different only in the caudal region of the mandible; this is the region that is constrained in size in all morphs. Conclusion Our data provides the first detailed description of the jaw dentitions of two morphs of Astyanax mexicanus, as well as in F1 hybrids. Tooth number, patterning and cuspal morphology are enhanced in cavefish in all jaws. This is in contrast to the increase in tooth number

  2. Internal kinematics of the tongue in relation to muscle activity and jaw movement in the pig

    PubMed Central

    LIU, Z.-J.; SHCHERBATYY, V.; KAYALIOGLU, M.; SEIFI, A.

    2012-01-01

    SUMMARY To explore the coordinative characteristics of tongue deformation, muscle activity and jaw movement during feeding, six ultrasonic crystals were implanted into the tongue body of ten 12-week-old Yucatan minipigs 1 week before the recording. These crystals formed a wedge-shaped configuration to allow recording dimensional changes in lengths, anterior and posterior widths and posterior thicknesses of the tongue body during feeding. Wire electromyographic activities (EMG) of superior and inferior longitudinalis, verticalis/transversus, genioglossus, styloglossus, masseter and digastricus and jaw movements were recorded simultaneously. Signals from these three sources were synchronized for real-time analyses. The results indicate: (i) dimensional changes were stereotypical in relation to each cycle of all three feeding behaviours; (ii) during chewing, expansion of tongue widths mainly occurred in the occlusal phase of jaw movement and was less coupled with the activity of tongue muscles, but the expansions of length and thickness were seen in the opening and closing phases and were better coupled with the activity of tongue muscles (P < 0·05); (iii) ingestion was characterized by the two-phased jaw opening, early expansion of anterior width prior to the occlusal phase and strong associations between tongue deformation and muscle activity; (iv) during drinking, the duration of the opening and closing phases was significantly prolonged (P < 0·01), the durations of tongue widening and lengthening were significantly shortened (P < 0·05) and anterior widening was predominant in the opening rather than in the closing or occlusal phases as compared with chewing and ingestion; and (v) the intrinsic tongue muscles did not show more or stronger correlations with the tongue deformation than did the extrinsic tongue muscles. These results suggest that (i) regional widening, lengthening and thickening of the tongue body occurs sequentially in relation to jaw movement

  3. Analysis of rhythmical jaw movements produced by taste stimulation in rats.

    PubMed

    Sasamoto, K; Nishimuta, K; Yasumatsu, K; Ninomiya, Y

    2001-04-01

    Taste stimulation of the mouth induces various oral movements. Sucrose or salt solution induces rhythmical jaw movements (RJM) or tongue protrusion as an ingestive behavior. Bitter taste induces a gaping or tongue retraction as an aversive behavior. There is no report that describes the precise pattern of jaw movements induced by taste stimulation. The purpose of the present study is to clarify the pattern of the taste-induced RJM with electromyographic activities of the masticatory muscles in the anesthetized rat. When water was injected into the mouth of the rat, an RJM was induced. In this type of RJM, the lower jaw swung right and left side in each open-close cycle alternately. The anterior digastric muscle was active in every opening phase, while activities of the jaw closing muscles were generally weak. The RJM induced by water was opening-dominant movements. Sucrose or salt solution induced a similar pattern of RJM to water-induced RJM. When acetic acid was injected, amplitude of the alternate lateral jaw movement was significantly larger than that in the water-induced RJM. The activity of the superficial temporalis muscle was large in those closing phases with ipsilateral side movement, while it was small in the closing phases with contralateral movement. The pattern of quinine-induced RJM was characterized by small lateral, large open-close and large antero-posterior movements. Tastes which are reported to induce ingestive behavior such as sweet or salty don't alter the pattern of RJM; however, the tastes which induce aversive behavior make the pattern of RJM different from the water-induced RJM.

  4. Development of the cypriniform protrusible jaw complex in Danio rerio: constructional insights for evolution.

    PubMed

    Staab, Katie Lynn; Hernandez, L Patricia

    2010-07-01

    Studies on the evolution of complex biological systems are difficult because the construction of these traits cannot be observed during the course of evolution. Complex traits are defined as consisting of multiple elements, often of differing embryological origins, with multiple linkages integrated to form a single functional unit. An example of a complex system is the cypriniform oral jaw apparatus. Cypriniform fishes possess an upper jaw characterized by premaxillary protrusion during feeding. Cypriniforms effect protrusion via the kinethmoid, a synapomorphy for the order. The kinethmoid is a sesamoid ossification suspended by ligaments attaching to the premaxillae, maxillae, palatines, and neurocranium. Upon mouth opening, the kinethmoid rotates as the premaxillae move anteriorly. Along with bony and ligamentous elements, there are three divisions of the adductor mandibulae that render this system functional. It is unclear how cypriniform jaws evolved because although the evolution of sesamoid elements is common, the incorporation of the kinethmoid into the protrusible jaw results in a function that is atypical for sesamoids. Developmental studies can show how biological systems are assembled within individuals and offer clues about how traits might have been constructed during evolution. We investigated the development of the protrusible upper jaw in zebrafish to generate hypotheses regarding the evolution of this character. Early in development, the adductor mandibulae arises as a single unit. The muscle divides after ossification of the maxillae, on which the A1 division will ultimately insert. A cartilaginous kinethmoid first develops within the intermaxillary ligament; it later ossifies at points of ligamentous attachment. We combine our structural developmental data with published kinematic data at key developmental stages and discuss potential functional advantages in possessing even the earliest stages of a system for protrusion.

  5. Heterogeneous conservation of Dlx paralog co-expression in jawed vertebrates.

    PubMed

    Debiais-Thibaud, Mélanie; Metcalfe, Cushla J; Pollack, Jacob; Germon, Isabelle; Ekker, Marc; Depew, Michael; Laurenti, Patrick; Borday-Birraux, Véronique; Casane, Didier

    2013-01-01

    The Dlx gene family encodes transcription factors involved in the development of a wide variety of morphological innovations that first evolved at the origins of vertebrates or of the jawed vertebrates. This gene family expanded with the two rounds of genome duplications that occurred before jawed vertebrates diversified. It includes at least three bigene pairs sharing conserved regulatory sequences in tetrapods and teleost fish, but has been only partially characterized in chondrichthyans, the third major group of jawed vertebrates. Here we take advantage of developmental and molecular tools applied to the shark Scyliorhinus canicula to fill in the gap and provide an overview of the evolution of the Dlx family in the jawed vertebrates. These results are analyzed in the theoretical framework of the DDC (Duplication-Degeneration-Complementation) model. The genomic organisation of the catshark Dlx genes is similar to that previously described for tetrapods. Conserved non-coding elements identified in bony fish were also identified in catshark Dlx clusters and showed regulatory activity in transgenic zebrafish. Gene expression patterns in the catshark showed that there are some expression sites with high conservation of the expressed paralog(s) and other expression sites with events of paralog sub-functionalization during jawed vertebrate diversification, resulting in a wide variety of evolutionary scenarios within this gene family. Dlx gene expression patterns in the catshark show that there has been little neo-functionalization in Dlx genes over gnathostome evolution. In most cases, one tandem duplication and two rounds of vertebrate genome duplication have led to at least six Dlx coding sequences with redundant expression patterns followed by some instances of paralog sub-functionalization. Regulatory constraints such as shared enhancers, and functional constraints including gene pleiotropy, may have contributed to the evolutionary inertia leading to high

  6. Heterogeneous Conservation of Dlx Paralog Co-Expression in Jawed Vertebrates

    PubMed Central

    Debiais-Thibaud, Mélanie; Metcalfe, Cushla J.; Pollack, Jacob; Germon, Isabelle; Ekker, Marc; Depew, Michael; Laurenti, Patrick

    2013-01-01

    Background The Dlx gene family encodes transcription factors involved in the development of a wide variety of morphological innovations that first evolved at the origins of vertebrates or of the jawed vertebrates. This gene family expanded with the two rounds of genome duplications that occurred before jawed vertebrates diversified. It includes at least three bigene pairs sharing conserved regulatory sequences in tetrapods and teleost fish, but has been only partially characterized in chondrichthyans, the third major group of jawed vertebrates. Here we take advantage of developmental and molecular tools applied to the shark Scyliorhinus canicula to fill in the gap and provide an overview of the evolution of the Dlx family in the jawed vertebrates. These results are analyzed in the theoretical framework of the DDC (Duplication-Degeneration-Complementation) model. Results The genomic organisation of the catshark Dlx genes is similar to that previously described for tetrapods. Conserved non-coding elements identified in bony fish were also identified in catshark Dlx clusters and showed regulatory activity in transgenic zebrafish. Gene expression patterns in the catshark showed that there are some expression sites with high conservation of the expressed paralog(s) and other expression sites with events of paralog sub-functionalization during jawed vertebrate diversification, resulting in a wide variety of evolutionary scenarios within this gene family. Conclusion Dlx gene expression patterns in the catshark show that there has been little neo-functionalization in Dlx genes over gnathostome evolution. In most cases, one tandem duplication and two rounds of vertebrate genome duplication have led to at least six Dlx coding sequences with redundant expression patterns followed by some instances of paralog sub-functionalization. Regulatory constraints such as shared enhancers, and functional constraints including gene pleiotropy, may have contributed to the evolutionary

  7. Modulation of jaw muscle spindle afferent activity following intramuscular injections with hypertonic saline.

    PubMed

    Ro, J Y; Capra, N F

    2001-05-01

    Transient noxious chemical stimulation of small diameter muscle afferents modulates jaw movement-related responses of caudal brainstem neurons. While it is likely that the effect is mediated from the spindle afferents in the mesencephalic nucleus (Vmes) via the caudally projecting Probst's tract, the mechanisms of pain induced modulations of jaw muscle spindle afferents is not known. In the present study, we tested the hypothesis that jaw muscle nociceptors gain access to muscle spindle afferents in the same muscle via central mechanisms and alter their sensitivity. Thirty-five neurons recorded from the Vmes were characterized as muscle spindle afferents based on their responses to passive jaw movements, muscle palpation, and electrical stimulation of the masseter nerve. Each cell was tested by injecting a small volume (250 microl) of either 5% hypertonic and/or isotonic saline into the receptor-bearing muscle. Twenty-nine units were tested with 5% hypertonic saline, of which 79% (23/29) showed significant modulation of mean firing rates (MFRs) during one or more phases of ramp-and-hold movements. Among the muscle spindle primary-like units (n = 12), MFRs of 4 units were facilitated, five reduced, two showed mixed responses and one unchanged. In secondary-like units (n = 17), MFRs of 9 were facilitated, three reduced and five unchanged. Thirteen units were tested with isotonic saline, of which 77% showed no significant changes of MFRs. Further analysis revealed that the hypertonic saline not only affected the overall output of muscle spindle afferents, but also increased the variability of firing and altered the relationship between afferent signal and muscle length. These results demonstrated that activation of muscle nociceptors significantly affects proprioceptive properties of jaw muscle spindles via central neural mechanisms. The changes can have deleterious effects on oral motor function as well as kinesthetic sensibility.

  8. Experimental muscle pain produces central modulation of proprioceptive signals arising from jaw muscle spindles.

    PubMed

    Capra, N F; Ro, J Y

    2000-05-01

    The aim of the present study was to investigate the effects of intramuscular injection with hypertonic saline, a well-established experimental model for muscle pain, on central processing of proprioceptive input from jaw muscle spindle afferents. Fifty-seven cells were recorded from the medial edge of the subnucleus interpolaris (Vi) and the adjacent parvicellular reticular formation from 11 adult cats. These cells were characterized as central units receiving jaw muscle spindle input based on their responses to electrical stimulation of the masseter nerve, muscle palpation and jaw stretch. Forty-five cells, which were successfully tested with 5% hypertonic saline, were categorized as either dynamic-static (DS) (n=25) or static (S) (n=20) neurons based on their responses to different speeds and amplitudes of jaw movement. Seventy-six percent of the cells tested with an ipsilateral injection of hypertonic saline showed a significant modulation of mean firing rates (MFRs) during opening and/or holding phases. The most remarkable saline-induced change was a significant reduction of MFR during the hold phase in S units (100%, 18/18 modulated). Sixty-nine percent of the DS units (11/16 modulated) also showed significant changes in MFRs limited to the hold phase. However, in the DS neurons, the MFRs increased in seven units and decreased in four units. Finally, five DS neurons showed significant changes of MFRs during both opening and holding phases. Injections of isotonic saline into the ipsilateral masseter muscle had little effect, but hypertonic saline injections made into the contralateral masseter muscle produced similar results to ipsilateral injections with hypertonic saline. These results unequivocally demonstrate that intramuscular injection with an algesic substance, sufficient to produce muscle pain, produces significant changes in the proprioceptive properties of the jaw movement-related neurons. Potential mechanisms involved in saline-induced changes in the

  9. Interspecific and intraspecific relationships between tooth size and jaw size in primates.

    PubMed

    Plavcan, J Michael; Daegling, David J

    2006-08-01

    The association between mandibular robusticity, postcanine megadontia, and canine reduction in hominins has led to speculation that large and robust jaws might be required to spatially accommodate large canine and molar teeth in hominins and other primates. If so, then variations in mandibular form that are generally regarded as biomechanical adaptations to masticatory demands might instead be incidental effects of functional requirements of tooth support. While the association between large teeth and deep, robust jaws in hominins is well known, the relationship between tooth size and jaw size has not been systematically evaluated in a comparative sample of primates. We evaluate the relationships between molar tooth size, canine tooth size, and mandibular corpus and symphyseal dimensions in a sample of adult anthropoids in interspecific (n=84 species) and intraspecific (n=36 species) contexts. For intraspecific comparisons, tooth size and jaw size are correlated, but for a majority of species this is a function of sexual size dimorphism. Interspecific comparisons lend little direct support to the hypothesis that jaw breadth directly covaries with molar tooth breadth, but they do support the hypothesis that mandibular depth is associated with canine tooth size in males. The latter observation suggests that if there is a causal association between canine size and mandibular depth, it is subject to a threshold effect. In contrast, neither corpus nor symphyseal robusticity, measured as a shape index of breadth/height, are correlated with tooth size. Our results suggest that further studies of the relationship between tooth size and corpus morphology should focus on tooth root size and corpus bony architecture, and that species-specific factors should have a strong impact on such relationships.

  10. Changes in rabbit jaw-muscle activity parameters in response to reduced masticatory load.

    PubMed

    Grünheid, T; Brugman, P; Zentner, A; Langenbach, G E J

    2010-03-01

    Mechanical food properties influence the neuromuscular activity of jaw-closing muscles during mastication. It is, however, unknown how the activity profiles of the jaw muscles are influenced by long-term alterations in masticatory load. In order to elucidate the effect of reduced masticatory load on the daily habitual activity profiles of three functionally different jaw muscles, the electromyograms of the masseter, temporalis and digastric muscles were recorded telemetrically in 16 male rabbits between seven and 20 weeks of age. Starting at eight weeks of age the experimental animals were fed significantly softer pellets than the control animals. Daily muscle activity was quantified by the relative duration of muscle use (duty time), burst number and burst length in relation to multiple activity levels. The daily duty time and burst number of the masseter muscle were significantly lower in the experimental group than in the control group at 5% and 10% of the maximum activity during the two weeks following the change in food hardness. By contrast, altered food hardness did not significantly influence the activity characteristics of the temporalis and digastric muscles. The findings suggest that a reduction in masticatory load decreases the neuromuscular activity of the jaw-closing muscles that are primarily responsible for force generation during mastication. This decrease is most pronounced in the weeks immediately following the change in food hardness and is limited to the activity levels that reflect muscle contractions during chewing. These findings support the conclusion that the masticatory system manifests few diet-specific long-term changes in the activity profiles of jaw muscles.

  11. Water temperature induces jaw deformity and bone morphogenetic proteins (BMPs) gene expression in golden pompano Trachinotus ovatus larvae.

    PubMed

    Ma, Zhenhua; Zhang, Nan; Qin, Jian G; Fu, Mingjun; Jiang, Shigui

    2016-01-01

    Golden pompano Trachinotus ovatus larvae were kept at 26, 29 and 33 °C for 15 days from 3-day post hatching (DPH) to 18 DPH to test temperature-dependent growth and jaw malformation. The growth, survival, jaw deformity and the gene expressions of bone morphogenetic proteins (BMPs) were used as criteria to examine the fish response to temperature manipulation. The growth rate of fish at 29 or 33 °C was significantly faster than fish at 26 °C, while fish survival at 29 °C was significantly higher than fish at 33 °C. Jaw deformity was significantly affected by water temperature. The highest jaw deformity occurred on fish at 33 °C, and the lowest jaw deformity was at 26 °C. The expressions of all BMP genes except BMP10 were significantly affected by water temperature. The highest gene expression of BMP2 was on fish at 29 °C, and the lowest expression was at 33 °C. For the BMP4 gene, the highest and lowest expressions were found on fish at 33 and 26 °C, respectively. The present study indicates that jaw deformity of golden pompano larvae increases with increasing temperature, and the gene expression of BMP4 proteins coincides with high jaw deformity and water temperature elevation.

  12. A biomechanical modeling study of the effects of the orbicularis oris muscle and jaw posture on lip shape.

    PubMed

    Stavness, Ian; Nazari, Mohammad Ali; Perrier, Pascal; Demolin, Didier; Payan, Yohan

    2013-06-01

    The authors' general aim is to use biomechanical models of speech articulators to explore how possible variations in anatomical structure contribute to differences in articulatory strategies and phone systems across human populations. Specifically, they investigated 2 issues: (a) the link between lip muscle anatomy and variability in lip gestures and (b) the constraints of coupled lip/jaw biomechanics on jaw posture in labial sounds. The authors used a model coupling the jaw, tongue, and face. First, the influence of the orbicularis oris (OO) anatomical implementation was analyzed by assessing how changes in depth (from epidermis to the skull) and peripheralness (proximity to the lip horn center) affected lip shaping. Second, the capability of the lip/jaw system to generate protrusion and rounding, or labial closure, was evaluated for different jaw heights. Results showed that a peripheral and moderately deep OO implementation is most appropriate for protrusion and rounding; a superficial implementation facilitates closure; protrusion and rounding require a high jaw position; and closure is achievable for various jaw heights. Models provide objective information regarding possible links between anatomical and speech production variability across humans. Comparisons with experimental data will illustrate how motor control and cultural factors cope with these constraints.

  13. A method for accurate zero calibration of asymmetric jaws in single-isocenter half-beam techniques

    SciTech Connect

    Hernandez, V.; Abella, R.; Lopez, M.; Perez, M.; Artigues, M.; Sempau, J.; Arenas, M.

    2013-02-15

    Purpose: To present a practical method for calibrating the zero position of asymmetric jaws that provides higher accuracy at the central axis and improves dose homogeneity in the abutting region of half-beams. Methods: Junction doses were measured for each asymmetric jaw using the double-exposure technique and electronic portal imaging devices. The junction dose was determined as a function of jaw position. The shift in the zero jaw position (or in its corresponding potentiometer readout) required to correct for the measured junction dose could thus be obtained. The jaw calibration was then modified to introduce the calculated shift and therefore achieve an accurate zero position in order to provide a relative junction dose that was as close to zero as possible. Results: All the asymmetric jaws from four medical linear accelerators were calibrated with the new calibration procedure. Measured relative junction doses at gantry 0 Degree-Sign were reduced from a maximum of {+-}40% to a maximum of {+-}8% for all the jaws in the four considered accelerators. These results were valid for 6 MV and 18 MV photon beams and for any combination of asymmetric jaws set to zero. The calibration was stable over a long period of time; therefore, the need for recalibrating is seldom necessary. Conclusions: Accurate calibration of the zero position of the jaws is feasible in current medical linear accelerators. The proposed procedure is fast and it improves dose homogeneity at the junction of half-beams, thus, allowing a more accurate and safer use of these techniques.

  14. Is GERD a Factor in Osteonecrosis of the Jaw? Evidence of Pathology Linked to G6PD Deficiency and Sulfomucins

    PubMed Central

    Swanson, Nancy L.; Li, Chen

    2016-01-01

    Osteonecrosis of the jaw (ONJ), a rare side effect of bisphosphonate therapy, is a debilitating disorder with a poorly understood etiology. FDA's Adverse Event Reporting System (FAERS) provides the opportunity to investigate this disease. Our goals were to analyze FAERS data to discover possible relationships between ONJ and specific conditions and drugs and then to consult the scientific literature to deduce biological explanations. Our methodology revealed a very strong association between gastroesophageal reflux and bisphosphonate-induced ONJ, suggesting acidosis as a key factor. Overgrowth of acidophilic species, particularly Streptococcus mutans, in the oral microbiome in the context of insufficient acid buffering due to impaired salivary glands maintains the low pH that sustains damage to the mucosa. Significant associations between ONJ and adrenal insufficiency, vitamin C deficiency, and Sjögren's syndrome were found. Glucose 6 phosphate dehydrogenase (G6PD) deficiency can explain much of the pathology. An inability to maintain vitamin C and other antioxidants in the reduced form leads to vascular oxidative damage and impaired adrenal function. Thus, pathogen-induced acidosis, hypoxia, and insufficient antioxidant defenses together induce ONJ. G6PD deficiency and adrenal insufficiency are underlying factors. Impaired supply of adrenal-derived sulfated sterols such as DHEA sulfate may drive the disease process. PMID:27773962

  15. Imaging findings of bisphosphonate-related osteonecrosis of the jaw with emphasis on early magnetic resonance imaging findings.

    PubMed

    Krishnan, Anant; Arslanoglu, Atilla; Yildirm, Nadir; Silbergleit, Richard; Aygun, Nafi

    2009-01-01

    To describe the imaging findings of bisphosphonate-related osteonecrosis of the jaw (BRONJ) with emphasis on early magnetic resonance imaging (MRI) findings. The medical records and computed tomography, MRI, and bone scintigraphy images of 5 female and 1male patients (n = 6) between the ages of 49 and 79 years (mean age, 70 years) who had a diagnosis of BRONJ were retrospectively reviewed, and temporal changes in imaging features were noted. The earliest MRI finding was the loss of the normal T1 hyperintensity of fatty marrow in the mandible and maxilla. The MRI findings of more advanced BRONJ included bone destruction, soft tissue edema and enhancement, inferior alveolar nerve thickening, and pterygoid muscle swelling and enhancement. On computed tomography, sclerosis and subtle lucencies (widening) of the periodontal ligament and cortex and around the apices of the teeth in the early stage, and osteolytic bone lesions, cortical disruption, and frank bone fragmentation in the later stages were observed. Bone scintigraphy showed increased uptake early in the disease. Osteonecrosis of the mandible and maxilla occurs as a complication of bisphosphonate treatment of bone metastasis and osteoporosis and typically manifests after a dental procedure. Magnetic resonance imaging and bone scintigraphy findings may precede clinical symptoms and mimic metastatic disease.

  16. Spontaneous Osteonecrosis of the Jaws in the Maxilla of Mice on Antiresorptive Treatment: A Novel ONJ Mouse Model

    PubMed Central

    de Molon, Rafael Scaf; Cheong, Simon; Bezouglaia, Olga; Dry, Sarah M; Pirih, Flavia; Cirelli, Joni Augusto; Aghaloo, Tara L; Tetradis, Sotirios

    2015-01-01

    Although osteonecrosis of the jaws (ONJ), a serious complication of antiresorptive medications, was reported a decade ago, the exact mechanisms of disease pathophysiology remain elusive. ONJ-like lesions can be induced in animals after antiresorptive treatment and experimental interventions such as tooth extraction or periapical or periodontal disease. However, experimental induction and manipulation of disease progression does not always reflect clinical reality. Interestingly, naturally occurring maxillofacial abscesses, inducing aggressive inflammation of the peri-radicular mucosa with significant osteolysis and alveolar bone expansion, have been reported in mice. Here, we aimed to explore whether osteonecrotic lesions would develop in areas of maxillary peri-radicular infections, in mice on antiresorptive medications with distinct pharmacologic action, thus establishing a novel ONJ animal model. Mice were treated with RANK-Fc or OPG-Fc that bind to RANKL or with the potent bisphosphonate zoledronic acid (ZA). Maxillae were assessed radiographically and histologically. μCT imaging of vehicle mice revealed several maxillae with altered alveolar bone morphology, significant ridge expansion and large lytic areas. However, in RANK-Fc, OPG-Fc and ZA treated animals the extent of bone loss was significantly less, but exuberant bone deposition was noted at the ridge periphery. BV and BV/TV were increased in the diseased site of antiresorptive vs. veh animals. Histologically, extensive inflammation, bone resorption and marginal gingival epithelium migratio