Wang, X-X; Wang, X; Li, Z-L; Yi, B; Liang, C; Jia, Y-L; Zou, B-S
To evaluate the feasibility of anterior maxillary segmental distraction (AMSD) to correct maxillary hypoplasia and severe dental crowding in cleft lip and palate (CLP) patients, 7 patients (average age 16.4 years) with maxillary hypoplasia, shortened maxillary dental arch length and severe anterior dental crowding secondary to CLP were selected for this study. After anterior maxillary segmental osteotomy, 3 patients were treated using bilateral internal distraction devices, and 4 patients were treated using rigid external distraction devices. Photographs and radiographs were taken to review the improvement in facial profile and occlusion after distraction. An average 10.25 mm anterior maxillary advancement was obtained in all patients after 10-23 days of distraction and 9-16 weeks of consolidation. The sella-nasion-point A (SNA) angle increased from 69.5 degrees to 79.6 degrees. Midface convexity was greatly improved and velopharyngeal competence was preserved. The maxillary dental arch length was greatly increased by 10.1 mm (P<0.01). Dental crowding and malocclusion were corrected by orthodontic treatment. These results show that AMSD can effectively correct the hypoplastic maxilla and severe dental crowding associated with CLP by increasing the midface convexity and dental arch length while preserving velopharyngeal function, and dental crowding can be corrected without requiring tooth extraction.
Bousdras, Vasilios A.; Liyanage, Chandra; Mars, Michael; Ayliffe, Peter R
Treatment of a wide alveolar cleft with initial application of segmental distraction osteogenesis is reported, in order to minimise cleft size prior to secondary alveolar bone grafting. The lesser maxillary segment was mobilised with osteotomy at Le Fort I level and, a novel distractor, facilitated horizontal movement of the dental/alveolar segment along the curvature of the maxillary dental arch. Following a latency period of 4 days distraction was applied for 7 days at a rate of 0.5 mm twice daily. Radiographic, ultrasonographic and clinical assessment revealed new bone and soft tissue formation 8 weeks after completion of the distraction phase. Overall the maxillary segment did move minimising the width of the cleft, which allowed successful closure with a secondary alveolar bone graft. PMID:24987601
Li, Hongliang; Dai, Jiewen; Si, Jiawen; Zhang, Jianfei; Wang, Minjiao; Shen, Steve Guofang; Yu, Hongbo
Anterior maxillary segmental distraction (AMSD) is an effective surgical procedure in the treatment of maxillary hypoplasia secondary to cleft lip and palate. Its unique advantage of preserving velopharyngeal function makes this procedure widely applied. In this study, the application of AMSD was described and its long-term stability was explored. Eight patients with severe maxillary hypoplasia secondary to CLP were included in this study. They were treated with AMSD using rigid external distraction (RED) device. Cephalometric analysis was performed twice at three time points for evaluation: before surgery (T1), after distraction (T2), and 2 years after treatment (T3). One-way analysis of variance was used to assess the differences statistically. All the distractions completed smoothly, and maxilla was distracted efficiently. The value of SNA, NA-FH, Ptm-A, U1-PP, overjet and PP (ANS-PNS) increased significantly after the AMSD procedure (P < 0.05), with the mean overjet increased by 14.28 mm. However, comparison of cephalometric analysis between T2 and T3 showed no significant difference (P > 0.05). Changes of palatopharyngeal depth and soft palatal length were insignificant. AMSD with RED device provided an effective way to correct maxillary hypoplasia secondary to CLP, extended the palatal and arch length, avoided damage on velopharyngeal closure function and reduced the relapse rate. It is a promising and valuable technique in this potentially complicated procedure. PMID:26629107
Combs, Patrick D.; Harshbarger, Raymond J.
Treatment of maxillary hypoplasia has traditionally involved conventional Le Fort I osteotomies and advancement. Advancements of greater than 10 mm risk significant relapse. This risk is greater in the cleft lip and palate population, whose anatomy and soft tissue scarring from prior procedures contributes to instability of conventional maxillary advancement. Le Fort I advancement with distraction osteogenesis has emerged as viable, stable treatment modality correction of severe maxillary hypoplasia in cleft, syndromic, and noncleft patients. In this article, the authors provide a review of current data and recommendations concerning Le Fort I advancement with distraction osteogenesis. In addition, they outline their technique for treating severe maxillary hypoplasia with distraction osteogenesis using internal devices. PMID:25383054
Rachmiel, Adi; Even-Almos, Michal; Aizenbud, Dror
Purpose: The purpose of this paper is to compare the treatment of hypoplastic, retruded maxillary cleft palate using distraction osteogenesis vs. orthognathic surgery in terms of stability and relapse, growth after distraction and soft tissue profile changes. Materials and Methods: The cleft patients showed anteroposterior maxillary hypoplasia with class III malocclusion and negative overjet resulting in a concave profile according to preoperative cephalometric measurements, dental relationship, and soft tissue analysis. The patients were divided in two groups of treatment : S0 eventeen were treated by orthognathic Le Fort I osteotomy fixed with four mini plates and 2 mm screws, and 19 were treated by maxillary distraction osteogenesis with rigid extraoral devices (RED) connected after a Le Fort I osteotomy. The rate of distraction was 1 mm per day to achieve Class I occlusion with slight overcorrection and to create facial profile convexity. Following a 10 week latency period the distraction devices were removed. Results: In the RED group the maxilla was advanced an average of 15.80 mm. The occlusion changed from class III to class I. The profile of the face changed from concave to convex. At a 1-year follow up the results were stable. The mean orthognathic movement was 8.4 mm. Conclusion: In mild maxillary deficiency a one stage orthognathic surgery is preferable. However, in patients requiring moderate to large advancements with significant structural deficiencies of the maxilla or in growing patients the distraction technique is preferred. PMID:23483803
Ylikontiola, Leena P.; Sándor, George K.; Harila, Virpi
Background: Cleft lip and palate patients often have a retruded maxilla with a severely narrowed deficient maxillary arch. This report aims to describe the management of severe maxillary retrusion and constriction in cleft lip and palate patients using distraction osteogenesis applied in serial sequence in two directions perpendicular to each other. Materials and Methods: Two adult male cleft lip and palate patients were treated with maxillary distraction osteogenesis in two stages. In the first stage, surgically assisted rapid palatal expansion with a tooth-borne device was performed to significantly expand the maxillary arch in the transverse dimension. After the teeth were orthodontically aligned, the horizontal distraction of the maxilla was made by two internal maxillary distraction devices. Results: In the first patient, the maxilla was initially widened by 11 mm and then distracted forward by 20 mm. Despite the breakage of the shaft of one of the two distractors at the end of distraction, a satisfactory occlusion was found at the time of distractor device removal. The maxillary position has remained stable through 8 years of follow-up. In the second patient, the palate was widened by 14 mm and the maxilla was distracted forward by 22 mm. The maxillary position has remained stable through 3 years of follow-up. Conclusion: Sequential serial distraction of maxilla in two planes perpendicular to each other is a safe and stable approach for the treatment of cleft lip and palate patients with severe transverse and anteroposterior discrepancies. PMID:26981462
Figueroa, Alvaro A; Polley, John W; Friede, Hans; Ko, Ellen W
Rigid external distraction is a highly effective technique for correction of maxillary hypoplasia in patients with orofacial clefts. The clinical results after correction of sagittal maxillary deformities in both the adult and pediatric age groups have been stable. The purpose of this retrospective longitudinal cephalometric study was to review the long-term stability of the repositioned maxilla in cleft patients who underwent maxillary advancement with rigid external distraction. Between April 1, 1995, and April 1, 1999, 17 consecutive patients with cleft maxillary hypoplasia underwent maxillary advancement using rigid external distraction. There were 13 male patients and four female patients, with ages ranging from 5.2 to 23.6 years (mean, 12.6 years). After a modified complete high Le Fort I osteotomy and a latency period of 3 to 5 days, patients underwent maxillary advancement with rigid external distraction until proper facial convexity and dental overjet and overbite were obtained. After active distraction, a 3- to 4-week period of rigid retention was undertaken; this was followed by removable elastic retention for 6 to 8 weeks using, during sleep time, an orthodontic protraction face mask. Cephalometric radiographs were obtained preoperatively, after distraction, at 1 year after distraction, and 2 or more years after distraction. The mean follow-up was 3.3 years (minimum, 2.1 years; maximum, 5.3 years). The following measurements were obtained in each cephalogram: three linear horizontal and two linear vertical maxillary measurements, two angular craniomaxillary measurements, and one craniomandibular measurement. Differences between the preoperative and postoperative cephalometric values were analyzed by paired t tests (p < 0.05). The cephalometric analysis demonstrated postoperatively significant advancement of the maxilla. In addition, the mandibular plane angle opened 1.2 degrees after surgery. After the 1- to 3-year follow-up period, the maxilla was
Yang, Lili; Suzuki, Eduardo Yugo; Suzuki, Boonsiva
Purposes: The purpose of this study was to compare the distraction forces and the biomechanical effects between two different intraoperative surgical procedures (down-fracture [DF] and non-DF [NDF]) for maxillary distraction osteogenesis. Materials and Methods: Eight patients were assigned into two groups according to the surgical procedure: DF, n = 6 versus NDF, n = 2. Lateral cephalograms taken preoperatively (T1), immediately after removal of the distraction device (T2), and after at least a 6 months follow-up period (T3) were analyzed. Assessment of distraction forces was performed during the distraction period. The Mann–Whitney U-test was used to compare the difference in the amount of advancement, the maximum distraction force and the amount of relapse. Results: Although a significantly greater amount of maxillary movement was observed in the DF group (median 9.5 mm; minimum-maximum 7.9-14.1 mm) than in the NDF group (median 5.9 mm; minimum-maximum 4.4-7.6 mm), significantly lower maximum distraction forces were observed in the DF (median 16.4 N; minimum-maximum 15.1-24.6 N) than in the NDF (median 32.9 N; minimum-maximum 27.6-38.2 N) group. A significantly greater amount of dental anchorage loss was observed in the NDF group. Moreover, the amount of relapse observed in the NDF group was approximately 3.5 times greater than in the DF group. Conclusions: In this study, it seemed that, the use of the NDF procedure resulted in lower levels of maxillary mobility at the time of the maxillary distraction, consequently requiring greater amounts of force to advance the maxillary bone. Moreover, it also resulted in a reduced amount of maxillary movement, a greater amount of dental anchorage loss and poor treatment stability. PMID:25593865
Kim, Su-Gwan; Mitsugi, Masaharu; Kim, Byung-Ock
This article describes a procedure for performing simultaneous sinus lifting and alveolar distraction to augment an atrophic maxillary alveolus. This technique is a 1-stage operation that is indicated when the amount of native sinus floor bone is minimal (<5 mm). The technique is contraindicated when there is <2 mm of sinus floor,when a 2-stage operation is needed (sinus lifting, alveolar distraction osteogenesis). Postoperative complications are minimal.
Boonzaier, James; Vicatos, George; Hendricks, Rushdi
The bones of the maxillary complex are vital for normal oro-nasal function and facial cosmetics. Maxillary tumor excision results in large defects that commonly include segments of the alveolar and palatine processes, compromising eating, speech and facial appearance. Unlike the conventional approach to maxillary defect repair by vascularized bone grafting, transport disc distraction osteogenesis (TDDO) stimulates new bone by separating the healing callus, and stimulates growth of surrounding soft tissues as well. Bone formed in this way closely mimics the parent bone in form and internal structure, producing a superior anatomical, functional and cosmetic result. Historically, TDDO has been successfully used to close small horizontal cleft defects in the maxilla, not exceeding 25 mm. Fujioka et al. reported in 2012 that "no bone transporter corresponding to the (large) size of the oro-antral fistula is marketed. The authors report the successful treatment of 4 cases involving alveolar defects of between 25 mm and 80 mm in length.
Silveira, Adriana da; Moura, Pollyana Marques de; Harshbarger, Raymond J.
The orthodontist plays a key role in the selection of the optimal treatment for patients followed by a craniofacial team. For patients with cleft lip and palate, the need for multidisciplinary treatment planning and sequentially staged treatment is essential for successful patient outcomes. The technique of Le Fort I distraction osteogenesis of the maxilla using an internal device is potentially a predictable, stable, and convenient option for the correction of severe maxillary hypoplasia. It is an alternative option for treatment of maxillary hypoplasia in growing patients. In this article, the authors describe the orthodontist's approach to the management of cleft patients with severe maxillary deficiency with the use of an internal distraction device. The information is presented with a focus on the clinical aspects of treatment, using case illustrations and appropriate literature. PMID:25383056
Tasanapanont, Jintana; Wattanachai, Tanapan; Apisariyakul, Janya; Pothacharoen, Peraphan; Kongtawelert, Prachya; Midtbø, Marit
Objective. To compare chondroitin sulphate (CS) levels around maxillary second premolars, first molars, and second molars between the unloaded and the loaded periods and to measure the rates of intrusion of maxillary posterior teeth during segmental posterior tooth intrusion. Materials and Methods. In this prospective clinical study, 105 teeth (from 15 patients exhibiting anterior open bite and requiring maxillary posterior tooth intrusion) were studied. Competitive ELISA was used to detect CS levels. Dental casts (during the unloaded and loaded periods) were scanned, and posterior tooth intrusion distances were measured. Results. During the unloaded period, the median CS levels around maxillary second premolars, first molars, second molars (experimental teeth), and mandibular first molars (negative control) were 0.006, 0.055, 0.056, and 0.012 and during the loaded period were 2.592, 5.738, 4.727, and 0.163 ng/μg of total protein, respectively. The median CS levels around experimental teeth were significantly elevated during the loaded period. The mean rates of maxillary second premolar and first and second molar intrusion were 0.72, 0.58, and 0.40 mm/12 weeks, respectively. Conclusions. Biochemical and clinical assessments suggested that the segmental posterior tooth intrusion treatment modality with 50 g of vertical force per side was sufficient. Trial Registration. The study is registered as TCTR20170206006. PMID:28321256
Meningaud, Jean-Paul; Pitak-Arnnop, Poramate; Corcos, Laurent; Bertrand, Jacques-Charles
The loss of mandibular molars can result in a maxillary dentoalveolar extrusion, leading to an insufficient interarch space. In severe cases, this space must be regained before the prosthetic reconstruction of the opposite edentulous area. The posterior maxillary segmental osteotomy (PMSO) is a simple but precision technique to manage this problem; without which one can achieve a good surgical outcome but a poor final occlusion. The purpose of this paper was to present a case of PMSO for mandibular implant placement and to discuss the important steps.
Chua, H D P; Whitehill, T L; Samman, N; Cheung, L K
This clinical randomized controlled trial was performed to compare the effects of distraction osteogenesis (DO) and conventional orthognathic surgery (CO) on velopharyngeal function and speech outcomes in cleft lip and palate (CLP) patients. Twenty-one CLP patients who required maxillary advancement ranging from 4 to 10 mm were recruited and randomly assigned to either CO or DO. Evaluation of resonance and nasal emission, nasoendoscopic velopharyngeal assessment and nasometry were performed preoperatively and at a minimum of two postoperative times: 3-8 months (mean 4 months) and 12-29 months (mean 17 months). Results showed no significant differences in speech and velopharyngeal function changes between the two groups. No correlation was found between the amount of advancement and the outcome measures. It was concluded that DO has no advantage over CO for the purpose of preventing velopharyngeal incompetence and speech disturbance in moderate cleft maxillary advancement.
Surgically assisted rapid mandibular expansion is a contemporary treatment alternative to enable genuine skeletal mandibular widening. Mandibular widening via a tooth-borne distractor is a practical and noninvasive clinical approach. Recently, to expand and protract the maxilla, the alternate rapid maxillary expansion-and-constriction procedure was suggested. In this case report, we describe a female patient (12 years 7 months old) having severe maxillary and mandibular crowding who underwent repeated alternate rapid maxillary expansion and constriction in combination with tooth-borne symphyseal distraction osteogenesis.
Takahashi, Ichiro; Kawamura, Hiroshi; Takano-Yamamoto, Teruko
This case report describes the treatment of a woman with severe mandibular retrusion and maxillomandibular transverse deficiency. Her malocclusion was characterized by a large overjet, a deep overbite, and a V-shaped dental arch, and she had a skeletal Class II profile. Treatement included combined maxillary and mandibular midline expansion, maxillary downward repositioning, and mandibular ramus lengthening with distraction osteogenesis with implants as orthodontic anchorage. During the postdistraction orthodontic treatment period, some skeletal relapse occurred. Implants provided absolute orthodontic anchorage to overcome the unexpected skeletal changes. Combined orthodontic treatment with implants for anchorage and distraction osteogenesis successfully expanded the maxilla and the mandible and corrected the mandibular deficiency. Two-year follow-up records show a morphologically and functionally stable result.
Neves, Paulo; Rosa, José; Bartlett, Scott
Summary: The authors present a new technique for reconstruction of large curvilinear mandibular defects with distraction osteogenesis and early open callus manipulation. In phase 1, transport disks are created from mandibular bone and distracted across the entire length of the defect, without the restriction from a mandible plate fixation. This allows for full-length distraction until enough regenerate is obtained to reconstruct the defect without the need for additional bone grafts. Taking advantage of the soft moldable regenerate, the second and final operative procedure allows for the manipulation, repositioning, and fixation of the transported segments in the ideal position creating perfect tridimensional form and symmetry of the mandible arch. In addition, the consolidation phase is shortened by the early removal of distractors, substantially reducing the total length of treatment. This article describes 2 clinical cases treated according to this technique, one with a 6-cm mandibular defect where a sagittal plane manipulation was performed, and the other with a 7-cm defect and axial plane manipulation. Five years postsurgery, both patients had achieved full stable reconstruction without the need for bone grafting, and had obtained good facial symmetry, with no recorded complications. This technique serves to establish bone transport as a valuable alternative to bone free flaps in the reconstruction of large curvilinear segmental mandibular defects. PMID:28203515
Pereira, Alberto Rocha; Neves, Paulo; Rosa, José; Bartlett, Scott
The authors present a new technique for reconstruction of large curvilinear mandibular defects with distraction osteogenesis and early open callus manipulation. In phase 1, transport disks are created from mandibular bone and distracted across the entire length of the defect, without the restriction from a mandible plate fixation. This allows for full-length distraction until enough regenerate is obtained to reconstruct the defect without the need for additional bone grafts. Taking advantage of the soft moldable regenerate, the second and final operative procedure allows for the manipulation, repositioning, and fixation of the transported segments in the ideal position creating perfect tridimensional form and symmetry of the mandible arch. In addition, the consolidation phase is shortened by the early removal of distractors, substantially reducing the total length of treatment. This article describes 2 clinical cases treated according to this technique, one with a 6-cm mandibular defect where a sagittal plane manipulation was performed, and the other with a 7-cm defect and axial plane manipulation. Five years postsurgery, both patients had achieved full stable reconstruction without the need for bone grafting, and had obtained good facial symmetry, with no recorded complications. This technique serves to establish bone transport as a valuable alternative to bone free flaps in the reconstruction of large curvilinear segmental mandibular defects.
Karabekmez, Furkan Erol; Kleinheinz, Johannes; Jung, Susanne
The objectives of this study are to assess the velopharyngeal dimensions using cephalometric variables of the nasopharynx and oropharynx as well as to compare the Le Fort I osteotomy technique to Zisser's anterior maxillary osteotomy technique based on patients' outcomes within early and late postoperative follow-ups. 15 patients with severe maxillary deficiency treated with Le Fort I osteotomy and maxillary segmental osteotomy were assessed. Preoperative, early postoperative, and late postoperative follow-up lateral cephalograms, patient histories, and operative reports are reviewed with a focus on defined cephalometric landmarks for assessing velopharyngeal space dimension and maxillary movement (measured for three different tracing points). A significant change was found between preoperative and postoperative lateral cephalometric measurements regarding the distance between the posterior nasal spine and the posterior pharyngeal wall in Le Fort I osteotomy cases. However, no significant difference was found between preoperative and postoperative measurements in maxillary segmental osteotomy cases regarding the same measurements. The velopharyngeal area calculated for the Le Fort I osteotomy group showed a significant difference between the preoperative and postoperative measurements. Le Fort I osteotomy for advancement of upper jaw increases velopharyngeal space. On the other hand, Zisser's anterior maxillary segmental osteotomy does not alter the dimension of the velopharyngeal space significantly. PMID:26273615
Blæhr, Tue Lindberg
ABSTRACT Objectives The objective of the present systematic review was to test the hypothesis of no difference in transverse skeletal and dental arch expansion and relapse after segmental Le Fort I osteotomy versus surgically assisted rapid maxillary expansion. Material and Methods A MEDLINE (PubMed), Embase and Cochrane library search in combination with a hand-search of relevant journals was conducted by including human studies published in English from January 1, 2000 to June 1, 2016. Results The search provided 130 titles and four studies fulfilled the inclusion criteria. All the included studies were characterized by high risk of bias and meta-analysis was not possible due to considerable variation. Both treatment modalities significantly increase the transverse maxillary skeletal and dental arch width. The transverse dental arch expansion and relapse seems to be substantial higher with tooth-borne surgically assisted rapid maxillary expansion compared to segmental Le Fort I osteotomy. The ratio of dental to skeletal relapse was significantly higher in the posterior maxilla with tooth-borne surgically assisted rapid maxillary expansion. Moreover, a parallel opening without segment tilting was observed after segmental Le Fort I osteotomy. Conclusions Maxillary transverse deficiency in adults can be treated successfully with both treatment modalities, although surgically assisted rapid maxillary expansion seems more effective when large transverse maxillary skeletal and dental arch expansion is required. However, considering the methodological limitations of the included studies, long-term randomized studies assessing transverse skeletal and dental expansion and relapse with the two treatment modalities are needed before definite conclusions can be provided. PMID:28154745
Stokbro, K; Aagaard, E; Torkov, P; Bell, R B; Thygesen, T
This retrospective study evaluated the precision and positional accuracy of different orthognathic procedures following virtual surgical planning in 30 patients. To date, no studies of three-dimensional virtual surgical planning have evaluated the influence of segmentation on positional accuracy and transverse expansion. Furthermore, only a few have evaluated the precision and accuracy of genioplasty in placement of the chin segment. The virtual surgical plan was compared with the postsurgical outcome by using three linear and three rotational measurements. The influence of maxillary segmentation was analyzed in both superior and inferior maxillary repositioning. In addition, transverse surgical expansion was compared with the postsurgical expansion obtained. An overall, high degree of linear accuracy between planned and postsurgical outcomes was found, but with a large standard deviation. Rotational difference showed an increase in pitch, mainly affecting the maxilla. Segmentation had no significant influence on maxillary placement. However, a posterior movement was observed in inferior maxillary repositioning. A lack of transverse expansion was observed in the segmented maxilla independent of the degree of expansion.
Joss, C U; Triaca, A; Antonini, M; Kiliaridis, S; Kuijpers-Jagtman, A M
33 patients (27 females; 6 males) were retrospectively analysed for skeletal and dental relapse before distraction osteogenesis (DOG) of the mandibular anterior alveolar process at T1 (17.0 days), after DOG at T2 (mean 6.5 days), at T3 (mean 24.4 days), and at T4 (mean 2.0 years). Lateral cephalograms were traced by hand, digitized, superimposed, and evaluated. Skeletal correction (T3-T1) was mainly achieved through the distraction of the anterior alveolar segment in a rotational manner where the incisors were more proclined. The horizontal backward relapse (T4-T3) measured -0.8mm or 19.0% at point B (p<0.001) and -1.6mm or 25.0% at incision inferior (p<0.001). Age, gender, amount and type (rotational versus translational) of advancement were not correlated with the amount of relapse. High angle patients (NL/ML'; p<0.01) and patients with large gonial angle (p<0.05) showed significantly smaller relapse rates at point B. Overcorrection of the overjet achieved by the distraction was seen in a third of the patients and could be a reason for relapse. Considering the amount of skeletal relapse the DOG could be an alternative to bilateral sagittal split osteotomy for mandibular advancement in selected cases.
Tsegga, Tibebu; Wright, Thomas
Dental restorative space from the opposing dentition requires adequate distance for restorative material for an acceptable restoration. Typically, long-standing edentulous alveolar ridges will have vertical and or horizontal defects that require alveolar ridge augmentation for ideal dental implant restorations. Along with these defects, one will see the opposing dentition supra erupt which can obliterate the restorative space. Multiple surgical techniques have been described to address these dilemmas. The use of osteoperiosteal flaps has been described to address vertical height deficiencies. The purpose of this paper is to document and introduce a maxillary segmental osteoperiosteal flap intrusion to increase the restorative space with simultaneous dental implant placement. As with most dilemmas in treatment planning dental implants, multiple acceptable treatment options are available to the practitioner. This technique is another of many that can be added to the available options. When appropriately planned in select cases, this technique will result with ideal dental implant restorations without compromising the esthetic and functional harmony of the native dentition.
Koteswara Prasad, N. K.; Hussain, Syed Altaf; Chitharanjan, Arun B.; Murthy, Jyotsna
Open bite deformity following a successful midface advancement by distraction osteogenesis is a common complication. Temporary anchorage devices can be deployed during the distraction and post-distraction settling phases for restoring the occlusion even in severe cases. The following report describes the management of severe anterior open bite following maxillary distraction. PMID:25991895
Joss, C U; Triaca, A; Antonini, M; Kiliaridis, S; Kuijpers-Jagtman, A M
17 patients (14 female; 3 male) were analysed retrospectively for skeletal and dental relapse before distraction osteogenesis (DO) of the mandibular anterior alveolar process at T1 (17.0 days), after DO at T2 (mean 6.5 days), at T3 (mean 24.4 days), at T4 (mean 2.0 years), and at T5 (mean 5.5 years). Lateral cephalograms were traced by hand, digitized, superimposed, and evaluated. Skeletal correction (T5-T1) was mainly achieved through the distraction of the anterior alveolar segment in a rotational manner where the incisors were more proclined. The horizontal backward relapse (T5-T3) measured -0.3mm or 8.3% at point B (non-significant) and -1.8mm or 29.0% at incision inferior (p<0.01). Age, gender, amount and type (rotational vs. translational) of advancement were not correlated with the amount of relapse. High angle patients (NL/ML'; p<0.01) showed significant smaller relapse rates at point B. Overcorrection of the overjet achieved by the distraction could be a reason for dental relapse. Considering the amount of long-term skeletal relapse the DO could be an alternative to bilateral sagittal split osteotomy for mandibular advancement in selected cases.
Krishnan, Sriram; Subramaniam, Ramkumar
Background and objective: Mandibular reconstruction following tumor ablative surgery had been a challenge. It has gone through days of temporary stabilization with k-wire, stainless steel reconstruction plate to avascularized and vascularized bone grafts with varying degree of success and failure. Reconstruction with vascularized bone grafts, though most definitive, requires special expertise, expensive equipment, and long operative time. It also produces donor site morbidity and requires a significant learning curve. With the development of transport distraction techniques there has been a paradigm shift from “reconstructive” to “regenerative” surgery. The objective of this study was to identify the feasibility of an internal device for reconstruction of extensive mandibular defects. Methods and material: This article is to highlight a process of attempted mandibular regeneration in two cases using an indigenously designed distractor device. In individuals with extensive post ablative mandibular defects who were unwilling to have a secondary surgical site or were medically unfit for a long reconstructive procedure, the distraction technique can be used to reconstruct the lost mandibular structures. Conclusion: A satisfactory amount of regenerate was achieved using a bifocal distraction osteogenesis technique for extensive defects of the mandible. The custom made device which was used for this purpose was moderately satisfactory and requires further evaluation and refinement. PMID:22110823
Burstein, Fernando; Soldanska, Magdalena; Granger, Michael; Berhane, ChiChi; Schoemann, Mark
Abstract Maxillary hypoplasia that necessitates surgical advancement affects approximately 25% of patients born with cleft lip and palate. Syndromic conditions such as Crouzon may also be accompanied by significant maxillary hypoplasia. Severe maxillary hypoplasia can result in airway obstruction, malocclusion, proptosis, and facial disfigurement. For optimal stability, severe hypoplasia is best addressed with maxillary distraction osteogenesis. Twenty-two patients (15 boys, 7 girls, ages 6–16 years, mean age 10 years) with severe midface hypoplasia underwent midface distraction with new internal maxillary distraction (IMD) device at our institution. Total distraction distances ranged from 15 to 30 mm. There were no major complications, and all of them had improvement in functional and aesthetic parameters. There were 2 minor complications and 2 patients failed to distract the full distance because of converging vectors. Early maxillary distraction in patients with severe midface hypoplasia is a useful technique to provide interval correction of severe maxillary hypoplasia before skeletal maturity and definitive orthognathic surgery is contemplated, and it is a good tool to improve occlusion, aesthetics, and self-perception in younger patients. PMID:26080162
Bauer, Richard E; Ochs, Mark W
Maxillary surgery to correct dentofacial deformity has been practiced for almost 100 years. Significant advances have made maxillary surgery a safe and efficient means of correcting midface deformities. Anesthetic techniques, specifically hypotensive anesthesia, have allowed for safer working conditions. Landmark studies have proven manipulation and segmentalization of the maxilla is safe and allowed this surgery to become a mainstay in corrective jaw surgery. This article provides an overview of surgical techniques and considerations as they pertain to maxillary surgery for orthognathic surgery. Segmental surgery, openbite closure, vertical excess, grafting, and a technology update are discussed.
Kacem, A; Legoux, H; Le Tenier, M; Hamitouche, C; Arbab-Chirani, R
Objectives: This study was designed to evaluate the reliability of a semi-automatic segmentation tool for dento-maxillary osteolytic image analysis compared with manually defined segmentation in CBCT scans. Methods: Five CBCT scans were selected from patients for whom periapical radiolucency images were available. All images were obtained using a ProMax® 3D Mid Planmeca (Planmeca Oy, Helsinki, Finland) and were acquired with 200-μm voxel size. Two clinicians performed the manual segmentations. Four operators applied three different semi-automatic procedures. The volumes of the lesions were measured. An analysis of dispersion was made for each procedure and each case. An ANOVA was used to evaluate the operator effect. Non-paired t-tests were used to compare semi-automatic procedures with the manual procedure. Statistical significance was set at α = 0.01. Results: The coefficients of variation for the manual procedure were 2.5–3.5% on average. There was no statistical difference between the two operators. The results of manual procedures can be used as a reference. For the semi-automatic procedures, the dispersion around the mean can be elevated depending on the operator and case. ANOVA revealed significant differences between the operators for the three techniques according to cases. Conclusions: Region-based segmentation was only comparable with the manual procedure for delineating a circumscribed osteolytic dento-maxillary lesion. The semi-automatic segmentations tested are interesting but are limited to complex surface structures. A methodology that combines the strengths of both methods could be of interest and should be tested. The improvement in the image analysis that is possible through the segmentation procedure and CBCT image quality could be of value. PMID:25996572
Joss, C U; Triaca, A; Antonini, M; Kiliaridis, S; Kuijpers-Jagtman, A M
This study evaluated soft tissue changes in adult patients treated with distraction osteogenesis (DOG) of the anterior mandibular alveolar process and related it to different parameters. 33 patients (27 females; 6 males) were analysed retrospectively before surgery at T1 (17.0 days), after surgery at T2 (mean 6.5 days), at T3 (mean 24.4 days), and at T4 (mean 2.0 years). Lateral cephalograms were traced by hand, digitized, superimposed, and evaluated. Statistical analysis was carried out using Kolmogorov-Smirnov test, paired t test, Pearson's correlation coefficient, and linear backward regression analysis. 2 years postoperatively (T4), the net effect of the soft tissue at point B' was 100% of the advancement at point B whilst the lower lip (labrale inferior) followed the advancement of incision inferior to 46%. Increased preoperative age was correlated (p<0.05) with more horizontal backward movement (T4-T3) for labrale superior and pogonion'. Higher NL/ML' angles were significantly correlated (p<0.05) with smaller horizontal soft tissue change at point B'. Gender and the amount of skeletal and dental advancement were not correlated with postoperative soft tissue changes (T4-T3). DOG of the anterior mandibular alveolar process is a valuable alternative for mandibular advancement regarding soft tissue change and predictability.
Joss, C U; Triaca, A; Antonini, M; Kiliaridis, S; Kuijpers-Jagtman, A M
Soft tissue changes were analysed retrospectively in 17 patients following distraction osteogenesis (DO) of the mandibular anterior alveolar process. Lateral cephalograms were traced by hand, digitized, superimposed, and evaluated at T1 (17.0 days), after DO at T2 (mean 6.5 days), at T3 (mean 24.4 days), at T4 (mean 2.0 years), and at T5 (mean 5.5 years). Statistical analysis was carried out using Kolmogorov-Smirnov test, paired t-test, Pearson's correlation coefficient, and linear backward regression analysis. 5.5 years postoperatively, the net effect for the soft tissue at point B' was 88% of the advancement at point B while the lower lip (labrale inferior) followed the advancement of incision inferior to 24%. Increased preoperative age was correlated (p<0.05) with more horizontal backward movement (T5-T3) for labrale inferior and pogonion'. Higher NL/ML' angles were significantly correlated (p<0.05) to smaller horizontal soft tissue change at labrale inferior (T5-T3). The amount of advancement at point B was significantly correlated with an upward movement (T5-T3) of labrale inferior (p<0.01) and stomion inferior (p<0.05). It can be concluded that further change in soft tissues occurred between 2.0 and 5.5 years postoperatively. The physiological process of ageing and loss of soft tissue elasticity should be considered as possible reasons.
Welch, R D; Lewis, D D
Distraction osteogenesis and the use of circular external skeletal fixation has increased the capacity of veterinary surgeons to manage difficult orthopedic conditions including limb-length discrepancies, angular deformity, distal and severely comminuted fractures, and bone defects. This article discusses the historical developments of the Ilizarov method of distraction osteogenesis in veterinary surgery, circular external skeletal instrumentation, and the biological principles. There is also discussion of use of this method for correction of angular deformity and bone transport and complications associated with this technique.
... the road Your hands on the wheel Your mind on driving Distracted driving occurs when something gets in the way of you doing all 3 things. Examples include: Talking on a cell phone Reading or sending text messages Eating and drinking Grooming ( ...
Yu, Jack C.; Fearon, Jeffrey; Havlik, Robert J.; Buchman, Steve R.; Polley, John W.
LEARNING OBJECTIVES:: After studying this article, the participant should be able to: 1. Review the biomechanical principles and pertinent cellular and molecular biology of distraction osteogenesis of the craniofacial skeleton. 2. Describe the clinical indications and applications of distraction osteogenesis of the craniofacial skeleton. 3. Describe maxillary, mandibular, midface, and calvarial procedures in distraction osteogenesis. 4. Discuss the clinical outcomes and complications of distraction osteogenesis of the craniofacial skeleton.The year 2002 marked the end of the first decade in clinical distraction osteogenesis of the craniofacial skeleton. In this short period, its application has increased exponentially. More than 3000 cases have been performed according to a recent survey, and more than 700 articles have been written on this subject in the MEDLINE database since 1996. It is a powerful surgical tool and enables surgeons to achieve results not previously attainable. Despite all this, distraction osteogenesis is practiced by only a small number of plastic surgeons. This article reviews the biomechanical principles; the pertinent cellular and molecular biology; and the clinical indications, applications, controversies, and complications of distraction osteogenesis of the craniofacial skeleton.
Bouletreau, Pierre J; Warren, Stephen M; Longaker, Michael T
Distraction osteogenesis has become a mainstay in bone tissue engineering and has significantly improved our armamentarium for reconstructive craniomaxillofacial procedures. However, although the biomechanical, histological, and ultrastructural changes associated with distraction osteogenesis have been widely described, the molecular mechanisms governing the formation of new bone in the interfragmental gap of gradually distracted bone segments remain largely unclear. Recently, a rat model of mandibular distraction was described that provides an excellent environment for deciphering the molecular mechanisms that mediate distraction osteogenesis. This article presents the hypotheses and current research that have furthered knowledge of the molecular mechanisms that govern distraction osteogenesis. Recent studies have implicated a growing number of cytokines that are intimately involved in the regulation of bone synthesis and turnover. The gene regulation of numerous cytokines (transforming growth factor-beta1, -beta2, -beta3, bone morphogenetic proteins, insulin-like growth factor-1, fibroblast growth factor-2) and extracellular matrix proteins (osteonectin, osteopontin) during distraction osteogenesis have been best characterized and are discussed in this article. It is believed that understanding the biomolecular mechanisms that mediate membranous distraction osteogenesis may guide the development of targeted strategies designed to improve distraction osteogenesis and accelerate bone healing.
The contribution of the segmental osteotomies in the ortho-surgical protocols is no longer to demonstrate and found a new lease of life thanks to the combination with the bone distraction techniques. The osteotomy of Köle, initially described to close infraclusies, and then used to level very marked curves of Spee has more recently been used to correct anterior crowding. This support is therefore aimed at patients with an incisor and canine Class 2 but molar Class 1 with an isolated mandibular footprint. With minimal orthodontic preparation we can create in two weeks bilateral diastemas that will then be used to align the incisivocanin crowding without stripping or bicuspid extractions. Dental orthodontic movements can be resumed one month after the end of the distraction. This technique is therefore likely to avoid bicuspid extraction and replace some sagittal osteotomy advancement by correction of the overjet. It also helps to correct a incisors labial or lingual tipping playing on differential activation of the cylinders and the distractor. This segmental surgery can be combined with Le Fort 1 surgeries with correction of the transverse and associated meanings, but in a second time, to a mandibular advancement and/or a genioplasty.
Amir, Lisa R; Everts, Vincent; Bronckers, Antonius L J J
Bone has the capacity to regenerate in response to injury. During distraction osteogenesis, the renewal of bone is enhanced by gradual stretching of the soft connective tissues in the gap area between two separated bone segments. This procedure has received much clinical attention as a way to correct congenital growth retardation of bone tissue or to generate bone to fill skeletal defects. The process of bone regeneration involves a complex system of biological changes whereby mechanical stress is converted into a cascade of signals that activate cellular behavior resulting in (enhanced) formation of bone. Over the last decade, significant progress has been made in understanding the bone regeneration process during distraction osteogenesis. The mechanical and biological factors that are important for the success of the distraction treatment have been partially characterized and are discussed in this review.
Bell, W H; Harper, R P; Gonzalez, M; Cherkashin, A M; Samchukov, M L
The purpose of this investigation was to elucidate the biology of distraction osteogenesis during mandibular widening. Midsymphyseal vertical interdental osteotomies were performed in nine Macaca mulatta monkeys. After a latency period a tooth-borne appliance was activated at a rate of 0.5 mm twice a day for 7-10 days. The appliance was then stabilized for a period of 4 or 8 weeks. The distraction gap at the inferior portion of the symphysis was bridged completely by new bony trabeculae. Bone formation in the interdental area was apparently related to the surgical technique. Newly formed bony trabeculae were oriented parallel to the direction of distraction. The location of the osteotomy site with an adequate margin of alveolar bone contiguous with the adjacent teeth was necessary for the induction of the distraction osteogenesis. Disproportional movement between superior and inferior portions of the distracted segments was noted.
Batal, Hussam S; Cottrell, David A
Alveolar distraction osteogenesis can be a valuable tool for implant site development. Simultaneous regeneration of hard and soft tissue and an overall decrease in treatment time compared with other methods of site preparation can be an advantage. The authors advocate the concept of "prosthetically driven alveolar distraction." Surgical planning should begin with visualization of the final restoration to determine the volume and position of the soft and hard tissue deficiency. Surgical guides will help the surgeon determine the vector of distraction. Adherence to surgical principles to avoid damage to adjacent vital structures and maintain vascular supply to the transport segment is necessary for success. Bone grafting may be necessary before or after distraction to increase the surgical success of the procedure. Close follow-up is needed to verify the appropriate distraction vector and volume. Patient management and acceptance should be considered in distractor design and placement.
Boulétreau, P; Longaker, M T
Distraction osteogenesis has become a mainstay in bone engineering and the recent application of this technique to the membranous craniofacial skeleton has significantly improved our armamentarium for reconstructive craniomaxillofacial procedures. However, if the biomechanical, histological and ultrastructural changes associated with distraction osteogenesis have been widely described, the molecular mechanisms governing the formation of new bone in the interfragmental gap of gradually distracted bone segments remain largely unclear. Recently, our laboratory has described a rat mandibular distraction model that provides an excellent environment for deciphering the molecular mechanisms that mediate distraction osteogenesis. In this Article, we present the hypotheses and current research that have furthered our knowledge of the molecular mechanisms that govern distraction osteogenesis. Recent studies have implicated a growing number of cytokines that are intimately involved in the regulation of bone synthesis and turnover. The gene regulation of numerous cytokines (Transforming Growth Factor-B, Bone Morphogenetic Proteins, Insulin-like Growth Factor-1, Fibroblast Growth Factor-2) during distraction osteogenesis have been best characterized and will be discussed in this text. We believe that novel systems like the rat model will facilitate our understanding of the biomolecular mechanisms that mediate membranous distraction osteogenesis and will ultimately guide the development of targeted-strategies designed to accelerate bone healing.
Kumar, N. Nanda; Ravindran, C.
Introduction Compromised alveolar ridge in vertical and horizontal dimension is a common finding in patients visiting practitioners for dental prosthesis. Various treatment modalities are available for correction of deficient ridges among which alveolar distraction osteogenesis is one. Aim To study the efficacy of alveolar distraction osteogenesis in augmentation of alveolar ridges deficient in vertical dimension. Materials and Methods Ten patients aged 16 to 46 years with deficient alveolar ridge underwent ridge augmentation in 11 alveolar segments using the distraction osteogenesis method. For each patient a custom made distraction device was fabricated. The device was indigenously manufactured with SS-316 (ISO 3506). Results The vertical bone gain reached more than 10mm without the use of bone transplantation. Certain complications like incorrect vector of distraction, paresthesia, pain and loss of transport segment were encountered during the course of the study. Conclusion Alveolar vertical distraction osteogenesis is a reliable and predictable technique for both hard and soft tissue genesis. Implant placement is feasible with primary stability in neogenerated bone at the level of the distracted areas. PMID:26816991
Yen, S L; Shang, W; Shuler, C; Yamashita, D D
Although distraction osteogenesis can lengthen congenitally small mandibles, the distraction procedure can be difficult to control. To study the efficacy and safety of orthodontic spring guidance on bilateral mandibular distraction, an 8-mm anterior open bite was experimentally produced and corrected during bilateral mandibular distraction in rabbits. Orthodontic springs were attached to the anterior maxilla and mandible to redirect an ongoing distraction procedure. Sixteen rabbits underwent mandibular distraction: 6 rabbits received heavy springs (8 oz), 6 rabbits received light force springs (2 oz), and 4 rabbits served as control animals with anterior open bites without spring guidance. Nickel-titanium springs were applied during the last week of osseous distraction and the first week of consolidation. Distractors were left in place throughout a 2-month consolidation period. None of the animals developed fibrous union as a result of spring guidance. The 8-mm open bite did not close in the control group or in the light spring group after 2 weeks of spring wear or during the consolidation period. Heavy springs completely closed the experimental open bites within 2 weeks (P <.01, analysis of variance). Bite corrections did not change during the consolidation period. This study indicated that the addition of an orthodontic spring to a mandibular distraction procedure did not impair bone healing. With the distraction device in place, heavy spring forces redirected an ongoing mandibular distraction procedure and corrected an open bite, distraction side effect. Direct measurements, radiographic measurements, and tissue histologic factors described changes in segment position and shape of the distraction site.
Nair, Arvind; Kumar, J Phani; Venkataramana, V; Yuvaraj, A; Reddy, V Sridhar; Kumar, S Kishore
Background: The aim of this clinical prospective study is to apply and evaluate an approach to reduce the overall orthodontic treatment time, by means of dentoalveolar distraction osteogenesis to achieve rapid canine retraction using an indigenously developed intra-oral tooth-borne distraction device. Materials & Methods: This study was carried out in the Department of Orthodontics and Dentofacial Orthopedics. Four patients selected for the purpose of Maxillary and/or Mandibular canine distraction with a rigid custom-made, intra-oral distraction device made of stainless steel and were scheduled for orthodontic treatment with bilateral first premolar extraction and then subsequent bilateral canine teeth distalization. Results: In all the patients the canine teeth moved distally and made contact with the second premolars within 14-16 days range after which they were kept passive, with the appliance for a week of consolidation. The amount of canine retraction was in 7-7.5mms range, in all the patients, in each of the four quadrants studied. Bodily movement, tipping and buccal flaring of the canine teeth were noticed in all the cases. Conclusion: Combination of newer orthodontic appliances and the principles of biomechanics to maintain the control over rapid tooth movement, rapid canine distalization using distraction osteogenesis awaits further development before routine application, of this innovative and exciting approach. How to cite the article: Nair A, Kumar JP, Venkataramana V, Yuvaraj A, Reddy VS, Kumar SK. Dento-Alveolar distraction osteogenesis using rigid intra-oral tooth borne distraction device. J Int Oral Health 2014;6(2):106-13. PMID:24876710
Guerrero, C A; Bell, W H; Contasti, G I; Rodriguez, A M
Transverse mandibular deficiency with crowding of the mandibular anterior teeth is frequently present in patients with Class I and II malocclusions. The hallmarks of treatment by compensating orthodontics, functional appliances or orthopaedic devices are instability, compromised periodontium and compromised facial aesthetics. A new surgical technique has been developed to widen the mandible. The method is based upon gradual osteodistraction following vertical interdental symphyseal osteotomy. Ten patients with transverse mandibular deficiency and significant dental crowding were treated by symphyseal distraction and subsequent non-extraction decompensating orthodontic treatment. Either an intraoral tooth-borne Hyrax appliance or a new custom-made bone-borne osteodistractor was used to gradually widen the mandible. The surgical procedures were accomplished under local anaesthesia and intravenous sedation in an ambulatory surgical setting using an individualized distraction protocol. The appliances were activated 7 days after symphyseal osteotomies, once each day at a rate of 1 mm per day and stabilized for 30-40 days after distraction. After the segments were distracted, non-extraction orthodontic alignment of the mandibular anterior teeth was accomplished. The symphyseal distraction gaps were bridged by new bony regenerate. Distraction osteogenesis provided an efficient surgical alternative to orthognathic surgery for widening the mandible and treatment of transverse mandibular deficiency without extraction of teeth.
Aguirre, Inés Ulfe; Dogliotti, Pedro Luis
A patient having adequate records and diagnosed as having Binder syndrome is presented. Nasomaxillary hypoplasia requires a definitive treatment, use of bone grafts, upper maxillary osteotomies, and advancement or a combination of both. Bone grafts can be reabsorbed, and complete maxillary advance modifies normal occlusion in a certain way, because the posterior sector is not compromised. The aim of this case treatment is to create a new osseous surface that makes the eruption of the permanent dental pieces easier and gives the correct skeletal position to the upper maxilla with distraction osteogenesis combined with an orthopedic appliance, transmaxillary segment osteotomy, and subsequent orthodontics. The absence of the osseous surface in the upper maxilla and the presence of supernumeraries in the anterior region determined the permanence of most of the temporary dental pieces, resulting in the impossibility of making the exchange to permanent dental pieces. The technique and the devices are simple and easy to manipulate. After the treatment, an adequate dental relation is restored as well as effective advance of the upper maxillary bone; thus, an excellent functional and stable esthetic result is achieved, avoiding any complication of velopharingeal incompetence.
Suhr, M A A; Kreusch, Th
Five cases are presented to exemplify technical difficulties and complications which may be encountered when performing distraction osteogenesis in the facial skeleton. The procedure should be performed under close supervision by the surgical and orthodontic colleagues. Errors in the choice of vector may be managed by earlier removal of the distractor and subsequent traction on the previously osteotomized segments using orthodontic appliances and principles. Multiple distractors may be inserted in the same jaw and bimaxillary procedures are possible, increasing the likelihood of encountering technical difficulties. Detailed planning and close follow-up, with early recognition and active management of the complications, may be useful in ensuring a successful outcome of this versatile procedure.
Marchac, D; Arnaud, E
The distraction of the maxilla provides very useful possibilities in young children with unstable articulation and in infants in order to avoid excessively radical operations. The principles of the distraction are reviewed. The authors report 13 clinical cases and complications. The material needs to be perfected, as numerous incidents are still observed.
Overton, Tiffany L; Rives, Terry E; Hecht, Carrie; Shafi, Shahid; Gandhi, Rajesh R
While the number of motor vehicle crashes has declined over the years, crashes resulting from distracted driving are increasing in the United States resulting in significant morbidity and mortality. The national public seems to be aware of the dangers associated with using technology while driving, but continues to engage in this dangerous behaviour, and may be unaware of or underestimate the impact of cell phone use on their own driving performance. Problems associated with distracted driving are not limited to novice or teenage drivers; multifaceted universal prevention efforts aimed at impacting large segments of the population may have the greatest impact. Legislation limiting drivers' cell phone use has had little impact, possibly due to low regulation and enforcement. Behaviour change programmes, improved vehicle safety, and public awareness campaigns have been developed as potential preventive efforts to reduce accidents caused by distracted drivers.
... about one hour and 15 minutes in their vehicles every day? Unfortunately, people often treat this as ... easy access to information, entertainment, and communications, in-vehicle distractions are increasing – as is the temptation to ...
Hankemeier, S; Bastian, L; Gosling, T; Krettek, C
Callus distraction is based on the principle of regenerating bone by continuous distraction of proliferating callus tissue. It has become the standard treatment of significant leg shortening and large bone defects. Due to many problems and complications, exact preoperative planning, operative technique and careful postoperative follow-up are essential. External fixators can be used for all indications of callus distraction. However, due to pin tract infections, pain and loss of mobility caused by soft tissue transfixation, fixators are applied in patients with open growth plates, simultaneous lengthening with continuous deformity corrections, and increased risk of infection. Distraction over an intramedullary nail allows removal of the external fixator at the end of distraction before callus consolidation (monorail method). The intramedullary nail protects newly formed callus tissue and reduces the risk of axial deviation and refractures. Recently developed, fully intramedullary lengthening devices eliminate fixator-associated complications and accelerate return to normal daily activities. This review describes principles of callus distraction, potential complications and their management.
Chow, Angela; Lee, Hao-Fu; Trahar, Mary; Kawamoto, Henry; Vastardis, Heleni; Ting, Kang
Introduction Distraction osteogenesis has gained popularity because of the hypothesized concurrent soft-tissue expansion, which is believed to reduce postoperative relapse. Although many articles describe the immediate success of mandibular distraction, little research has been done on its long-term stability. Our goal was to examine the long-term craniofacial changes after distraction. Methods Four hemifacial microsomic patients treated with unilateral mandibular distraction were recalled. Changes in maxillary width and height, occlusal height, ramus height, mandibular length, and chin position were quantified by using the posteroanterior and 45° lateral oblique cephalographs. Predistraction and postdistraction measurements were taken over a 5-year period. The data were analyzed by using paired t tests and ANOVA. Results Maxillary height, ramus height, mandibular length, and chin point deviation all experienced moderate improvement after distraction. Although the growth patterns between the control side and the treated side were comparable until 2 years after removal of the device, the normal side outgrew the affected side thereafter until 5 years after distraction. Conclusions Because of the greater inherent growth potential of the unaffected side, more overcorrection than originally believed is needed to offset the persistent asymmetry in growing hemifacial microsomia patients who undergo unilateral distraction osteogenesis. PMID:19061798
Tuzuner-Oncul, Aysegul Mine; Kisnisci, Reha S
Vertical lengthening of the mandibular ramus is considered to be one of the least stable surgical procedures in the management of musculoskeletal maxillofacial deformities. The aim of this study was to evaluate the response of the mandibular ramus following vertical lengthening by means of distraction osteogenesis. This study included eight non-syndromic adult patients with temporomandibular joint ankylosis. The vertical height deficiency of the mandibular ramus and the ramus/condyle unit on the affected side were simultaneously reconstructed by transportation of a bone segment using distraction osteogenesis following gap arthroplasty. Lateral and posteroanterior (PA) cephalograms taken postoperatively before active distraction, at the completion of distraction and 6, 12, 24 months after distraction, were compared to evaluate the changes of the ramus height. In all cases the vertical ramus and ramus/condyle unit height loss were successfully reconstructed by distraction osteogenesis. There was no relapse in the amount of height gained by distraction osteogenesis at the 24 months follow-up review (p>0.05). Acute one stage vertical lengthening of the mandibular ramus is considered to be one of the least stable musculoskeletal procedures with relapse being a significant adverse outcome. In this clinical study gradual vertical lengthening of the ramus through ramus/condyle unit distraction osteogenesis has maintained the initial vertical ramus height gained for 24 months.
Flores, Roberto L
Mandibular distraction has revolutionized the treatment of Robin sequence associated with severe airway obstruction. The distraction technique remains the only intervention that directly corrects mandibular hypoplasia and the retropositioned tongue, providing efficient relief of airway stenosis. Multiple studies have demonstrated the efficacy of distraction in avoiding tracheostomy and decreasing the severity airway obstruction in this patient population. The benefit to avoiding tracheostomy and relieving airway obstruction is superior to that of tongue-lip adhesion. It is, therefore, not surprising that mandibular distraction has become the first-line intervention at many centers for the surgical treatment of Robin sequence. The complication profile associated with mandibular distraction appears low; the most common complication is infection, which can be treated by antibiotics alone. The severity of airway obstruction can be quantified by polysomnogram: This tool has become one of the most widely used objective metrics in the Robin sequence population. Therefore indications for surgery, timing of palatoplasty and long-term assessment of airway function should be performed in conjunction with sleep study analysis. The effects of mandibular lengthening on feeding difficulty in Robin sequence patient remains a topic of controversy. Studies have demonstrated conflicting results: This can be an area of future study. Agreed-upon indications for surgery and definitive protocols of care have yet to be formulized; future research should focus on achieving these goals. Such studies would require agreed-upon terminology for Robin sequence, an increase in comparative and prospective analysis, and the use of quantifiable metrics of clinical results.
Flores, Roberto L.
Mandibular distraction has revolutionized the treatment of Robin sequence associated with severe airway obstruction. The distraction technique remains the only intervention that directly corrects mandibular hypoplasia and the retropositioned tongue, providing efficient relief of airway stenosis. Multiple studies have demonstrated the efficacy of distraction in avoiding tracheostomy and decreasing the severity airway obstruction in this patient population. The benefit to avoiding tracheostomy and relieving airway obstruction is superior to that of tongue–lip adhesion. It is, therefore, not surprising that mandibular distraction has become the first-line intervention at many centers for the surgical treatment of Robin sequence. The complication profile associated with mandibular distraction appears low; the most common complication is infection, which can be treated by antibiotics alone. The severity of airway obstruction can be quantified by polysomnogram: This tool has become one of the most widely used objective metrics in the Robin sequence population. Therefore indications for surgery, timing of palatoplasty and long-term assessment of airway function should be performed in conjunction with sleep study analysis. The effects of mandibular lengthening on feeding difficulty in Robin sequence patient remains a topic of controversy. Studies have demonstrated conflicting results: This can be an area of future study. Agreed-upon indications for surgery and definitive protocols of care have yet to be formulized; future research should focus on achieving these goals. Such studies would require agreed-upon terminology for Robin sequence, an increase in comparative and prospective analysis, and the use of quantifiable metrics of clinical results. PMID:25383055
Zemsky, Robert; Shaman, Susan; Shapiro, Daniel B.
Presents a market taxonomy for higher education, including what it reveals about the structure of the market, the model's technical attributes, and its capacity to explain pricing behavior. Details the identification of the principle seams separating one market segment from another and how student aspirations help to organize the market, making…
Lewinson, Dina; Rachmiel, Adi; Rihani-Bisharat, Souhir; Kraiem, Zaki; Schenzer, Pesia; Korem, Sigal; Rabinovich, Yaron
Bone cells respond to mechanical stimulation by gene expression. The molecular events involved in the translation of mechanical stimulation into cell proliferation and bone formation are not yet well understood. We looked for the expression of early-response genes of the AP-1 transcription factor complex in an in vivo bone regeneration system subjected to mechanical forces because these genes were found to be related to mechanotransduction and important for bone development. Sheep maxillary bone was distracted daily for 15 days. c-Jun and c-Fos were evaluated by Northern blotting analysis and immunohistochemistry in biopsy specimens removed at 8 and 15 days and were compared with post-osteotomy but not distracted repair tissue. Elevated levels of c-Jun and c-Fos mRNA were found after 8 days of distraction. Likewise, mesenchyme-like and fibroblast-like cells composing the 8-day distracted regeneration tissue showed increases in the intensity of immunostaining compared to cells in the corresponding non-distracted fracture repair tissue. After 15 days of distraction, when bone trabeculae start to form distally and proximally in the distracted regeneration tissue, mostly preosteoblasts and osteoblasts retained c-Fos and c-Jun immunoreactivity, similar to bone-associated cells in control non-distracted fracture repair tissue. We propose that the elevated expression of c-Jun and c-Fos is related to mechanical stimulation in this in vivo bone regeneration system.
Mitsugi, Masaharu; Alcalde, Rafael E.; Yano, Tomoyuki; Uemura, Noriko; Okazaki, Mutsumi
Backgrounds: The main problem with intraoral distraction of the mandible is the inability to achieve the three-dimensional mandibular correction as planned preoperatively. We developed a technique that allows spontaneous changes in the direction of mandibular elongation using an intraoral distractor. Methods: After mandibular osteotomy, the distractor is fixed to the distal segment of the mandible using a single bicortical screw, allowing anterior-posterior, vertical and limited lateromedial changes in the vector of distraction. Mandibular lengthening is performed while keeping the maxilla and mandible in class I occlusion with intermaxillary fixation. Results: As the distraction device is activated allowing mandibular elongation, the proximal segment, guided by the surrounding soft tissues, moves and rotates posterosuperiorly. Mandibular lengthening is continued until the condylar head reaches an adequate position in the mandibular fossa as confirmed clinically and radiographically. Conclusion Thirty-three patients with mandibular retrognathia received this treatment and good results were obtained. PMID:26301156
Breuning, K H; de Lange, M; van Strijen, P J; Perdijk, F B T; Bolouri, S
A female patient (age 26) visited the orthodontist for correction of the reduced exposure of the upper incisors during laughing. She also reported crowding of the lower incisors and an association between lisping and her open bite. The diagnosis in this case: a Class III malocclusion case with incisor crowding and an open bite. Because her main complaint was reduced upper incisor exposure while talking and laughing, which would not be corrected with orthodontic appliances only, the position of the maxilla was corrected during orthodontic treatment by means of vertical intra-oral maxillary distraction. An acceptable and relatively stable result was achieved.
Wolfe, Elizabeth Suzanne; Arabian, Sandra Strack; Breeze, Janis L; Salzler, Matthew J.
Commuting via bicycle is a very popular mode of transportation in the Northeastern United States (US). Boston, MA has seen a rapid increase in bicycle ridership over the past decade which has raised concerns and awareness about bicycle safety. An emerging topic in this field is distracted bicycle riding. This study was conducted to provide descriptive data on the prevalence and type of distracted bicycling in Boston at different times of day. This was a cross-sectional study in which observers tallied bicyclists at four high traffic intersections in Boston during various peak commuting hours for two types of distractions: auditory (ear buds/phones in or on ears), and visual/tactile (electronic device or other object in hand). Nineteen hundred seventy-four bicyclists were observed and 615 (31.2%, 95% CI: 29%-33%) were distracted. Of those observed, auditory distractions were the most common (N= 349 [17.7%, 95% CI: 16%-19%], p=0.0003) followed by visual/tactile distractions (N= 266 [13.5%, 95% CI: 12%-15%]). The highest proportion (40.7%, 95% CI: 35%-46%) of distracted bicyclists was observed during the midday commute (between 13:30-15:00). Distracted bicycling is a prevalent safety concern in the city of Boston, as almost one-third of all bicyclists exhibited distracted behavior. Education and public awareness campaigns should be designed to decrease distracted bicycling behaviors and promote bicycle safety in Boston. An awareness of the prevalence of distracted biking can be utilized to promote bicycle safety campaigns dedicated to decreasing distracted bicycling and to provide a baseline against which improvements can be measured. PMID:26953533
Nocini, Pier Francesco; De Santis, Daniele; Ferrari, Francesca; Bertele, Gian Paolo
The purpose of this study was to develop an extraosseous, tooth-supported miniature intraoral device that could produce prosthetically driven bone distraction of small atrophic alveolar ridge segments. Extraosseous distraction requires that the distraction device be anchored to a dental implant previously placed into the ridge according to its anatomic axis. A distractor can also correct the position of implants placed in young patients before skeletal growth is completed. Similarly, it allows the alignment of ankylosed teeth not treatable by orthodontics. The device is made of (1) an engine consisting of an orthodontic micrometric screw; (2) a joint between the implant and the engine, ie, the ball attachment/o-ring system; and (3) an anchorage system to the oral cavity provided by an orthodontic appliance and a mini-implant for possible additional support. Surgery involves an osteotomy of the atrophic alveolar ridge segment, incorporating the implant, from the basal bone; afterward the device can be applied and distraction of the segment can be carried out. Distraction was successfully performed in 3 clinical cases: 2 bone-implant segments and 1 bone-ankylosed tooth segment. All cases were clinically uneventful. This mini-device for osteogenic distraction of small atrophic ridge segments can provide for accurate and precise ridge augmentation, as is required for ideal prosthetic rehabilitation.
FURQUIM, Laurindo Zanco; JANSON, Guilherme; FURQUIM, Bruno D’Aurea; IWAKI FILHO, Liogi; HENRIQUES, José Fernando Castanha; FERREIRA, Geovane Miranda
This case report describes the orthodontic treatment of a 32-year-old woman with a Class III malocclusion, whose chief compliant was her dentofacial esthetics. The pretreatment lateral cephalometric tracings showed the presence of a Class III dentoskeletal malocclusion with components of maxillary deficiency. After discussion with the patient, the treatment option included surgically assisted rapid maxillary expansion (SARME) followed by orthopedic protraction (Sky Hook) and Class III elastics. Patient compliance was excellent and satisfactory dentofacial esthetics was achieved after treatment completion. PMID:20857013
Kim, So-Yeon; Hopfinger, Joseph B.
The ability to maintain focus and avoid distraction by goal-irrelevant stimuli is critical for performing many tasks and may be a key deficit in attention-related problems. Recent studies have demonstrated that irrelevant stimuli that are consciously perceived may be filtered out on a neural level and not cause the distraction triggered by…
Khanduri, Sachin; Agrawal, Sumit; Goyal, Swati
Maxillary sinus hypoplasia (MSH) is an uncommon abnormality of paranasal sinuses noted in clinical practice. Computed tomography (CT) scan helps in diagnosing the anomaly along with any anatomical variation that may be associated with it. MSH is usually associated with other anomalies like uncinate process hypoplasia. Three types of MSH have been described. Type 1 MSH shows mild maxillary sinus hypoplasia, type 2 shows significant sinus hypoplasia with narrowed infundibular passage and hypoplastic or absent uncinate process, and type 3 is cleft like maxillary sinus hypoplasia with absent uncinate process. CT and endoscopic examination usually complement each other in diagnosing MSH. PMID:25548709
Kemper, Susan; Mcdowd, Joan; Metcalf, Kim; Liu, Chiung-Ju
Eye-tracking technology was employed to examine young and older adults' performance in the reading with distraction paradigm. Distracters of 1, 2, and 4 words that formed meaningful phrases were used. There were marked age differences in fixation patterns. Young adults' fixations to the distracters and targets increased with distracter length.…
Rowe, N M; Mehrara, B J; Luchs, J S; Dudziak, M E; Steinbrech, D S; Illei, P B; Fernandez, G J; Gittes, G K; Longaker, M T
Recruitment of a blood supply is critical for successful bone induction and fracture healing. Despite the clinical success of distraction osteogenesis (DO), an analysis of angiogenesis during membranous bone DO has not been performed. The purpose of this study was to evaluate the temporal and spatial pattern of angiogenesis during mandibular DO. The right hemimandible of adult male rats was osteotomized, and a customized distraction device was applied. Following a 3-day latency period, distraction was begun at a rate of 0.25 mm twice daily for 6 days (3.0 mm total; 12% increase in mandibular length). Three animals each were sacrificed on days 2, 4, and 6 of distraction (D1, D2, and D3 respectively), or after 1, 2, or 4 weeks of consolidation (C1, C2, and C3 respectively). Two experienced pathologists reviewed the regenerate histology, and angiogenesis was assessed by counting the number of blood vessels per intermediate-power field (IPF). Statistical analysis was performed using analysis of variance, with p < or = 0.05 considered significant. Results demonstrate that mandibular DO was associated with an intense vascular response during the early stages of distraction (D1). On average, 31.5+/-7.9 vessels were noted in each IPF examined during this time point. The number of blood vessels in the distraction regenerate decreased significantly during the later distraction time points, with approximately 14.0+/-2.0 and 14.7+/-3.5 blood vessels per IPF in sections obtained after days 4 and 6 of distraction (D2, D3) respectively. However, blood vessels at these time points took on a more mature histological pattern. During the consolidation period, the number of blood vessels noted in the regenerate decreased with 8.0+/-2.6, 9.3+/-2.1, and 4.0+/-2.0 vessels per IPF in sections obtained after 1, 2, or 4 weeks of consolidation (C1, C2, C3) respectively (p < 0.05 compared with vessel counts during the earliest distraction time point). This study demonstrates for the first
Adeola, Ruth; Gibbons, Mallory
Distracted driving is a growing problem in the United States. With the integration of wireless devices into everyday life, cell phone use behind the wheel is a distraction requiring increasing concern. Teen drivers are most susceptible to the dangers of distracted driving as made evident in the overrepresentation of teens in distraction-related motor vehicle crashes. This article describes the causes, consequences, and statistics related to distracted driving in teenagers and an injury prevention program for teenagers.
Yonezawa, Hisanobu; Yanamoto, Souichi; Hoshino, Tomonori; Yamada, Shin-Ichi; Fujiwara, Taku; Umeda, Masahiro
An 11-year-old male who injured his maxilla and right maxillary central incisor and lip during a fall was presented to our hospital. His lower lip and upper gingiva were lacerated with swelling and epistaxis, and he had a maxillary alveolar bone fracture and severe intrusion of the right maxillary central incisor, which had penetrated the floor of the nasal cavity with avulsion. Under local anesthesia, we repositioned the incisor and bone segment and fixed them with a titanium micromesh plate and self-tapping screws and splints. The incisor was also treated by root canal 3 days after the operation and was restored with a crown. We performed root canal filling 1 month later. Five months later, the plate and screws were removed. In prognosis of our case, no symptoms of inflammatory root resorption or ankylosis have observed for more than 1 year and 6 months of follow up based on both clinical and radiographic findings.
Blowers, G H
An attempt is made to replicate a former study of the relationship of field dependence as measured by rod-and-frame errors to distraction in an RT paradigm. For two groups of Ss (n = 14) who differed specifically in their dependence upon the tilted frame and were classified as frame-dependent and frame-independent, no relationship of frame (or field) dependence to susceptibility to distraction was found.
Kountouriotis, G K; Merat, N
Driver distraction is strongly associated with crashes and near-misses, and despite the attention this topic has received in recent years, the effect of different types of distracting task on driving performance remains unclear. In the case of non-visual distractions, such as talking on the phone or other engaging verbal tasks that do not require a visual input, a common finding is reduced lateral variability in steering and gaze patterns where participants concentrate their gaze towards the centre of the road and their steering control is less variable. In the experiments presented here, we examined whether this finding is more pronounced in the presence of a lead car (which may provide a focus point for gaze) and whether the behaviour of the lead car has any influence on the driver's steering control. In addition, both visual and non-visual distraction tasks were used, and their effect on different road environments (straight and curved roadways) was assessed. Visual distraction was found to increase variability in both gaze patterns and steering control, non-visual distraction reduced gaze and steering variability in conditions without a lead car; in the conditions where a lead car was present there was no significant difference from baseline. The lateral behaviour of the lead car did not have an effect on steering performance, a finding which indicates that a lead car may not necessarily be used as an information point. Finally, the effects of driver distraction were different for straight and curved roadways, indicating a stronger influence of the road environment in steering than previously thought.
Cheung, L K; Chua, Hannah Daile P
Maxillary deformities of cleft lip and palate (CLP) can be treated by either conventional osteotomies (CO) or distraction osteogenesis (DO). Which one is better for CLP patients suffering from a moderate extent of maxillary hypoplasia? The aim of the study was to evaluate the treatment outcomes of CO and compared with DO in correction of moderate maxillary hypoplasia. The results showed that CLP patients receiving DO were more anxious and depressed during the first three months but became happier in the long-term. The nasalance of DO and CO was found to be similar. However, on the skeletal stability, DO was shown to be significantly more stable when compared with CO in the horizontal plane within the first six months and in vertical plane during the first three months and between 1-2 year.
Horas, Konstantin; Schnettler, Reinhard; Maier, Gerrit; Horas, Uwe
An intramedullary device has some advantages over external fixation in callus distraction for bone defect reconstruction. There are difficulties controlling motorized intramedullary devices and monitoring the distraction rate which may lead to poor results. The aim of this study was to design a fully implantable and non-motorized simple distraction nail for the treatment of bone defects. The fully implantable device comprises a tube-in-tube system and a wire pulling mechanism for callus distraction. For the treatment of femoral bone defects, a traction wire, attached to the device at one end, is fixed to the tibial tubercle at its other end. Flexion of the knee joint over a predetermined angle generates a traction force on the wire triggering bone segment transport. This callus distraction system was implanted into the femur of four human cadavers (total 8 femora), and bone segment transport was conducted over 60-mm defects with radiographic monitoring. All bone segments were transported reliably to the docking site. From these preliminary results, we conclude that this callus distraction system offers an alternative to the current intramedullary systems for the treatment of bone defects.
Sunaga, Ataru; Kamochi, Hideaki; Oguma, Hirofumi; Sugawara, Yasushi
In this review, we discuss in detail our current procedure for treating craniosynostosis using multidirectional cranial distraction osteogenesis (MCDO). The MCDO method allows all phenotypes of skull deformity to be reshaped by distraction osteogenesis, except in patients who are 5 months of age or younger and patients with posterior cranial vault problems. We report the results of clinical data of 36 children with craniosynostosis who underwent MCDO between 2005 and 2014 in our institute. This method has the following benefits, such as a high flexibility of reshaping, shorter treatment period and less invasive secondary intervention. We also discuss the other distraction osteogenesis techniques that are used to treat craniosynostosis and compare them with MCDO. The preferred procedure for correction of craniosynostosis may depend on the patient's age, the extent of deformity, and the extent of correction achievable by surgery. We can arrange the combinations of various methods according to the advantage and disadvantage of each technique. PMID:27226854
... distractions caused by the use of PEDs. Such distractions may also hinder their prompt recognition and reaction... distractions caused by the use of PEDs. Such distractions may also hinder their prompt recognition and...
Jansma, J; Becking, A G
With distraction osteogenesis (DOG) formation of new bone is initiated by gradual separation of osteotomized bone fragments. Both external and internal distraction devices are available. Since its first application in craniomaxillofacial surgery in the early nineties, developments in distraction osteogenesis have been tremendous. Important advantages of this technique are: lack of a donorsite and its associated morbidity; increase of the volume of the soft tissue envelop; less surgical trauma compared to conventional craniomaxillofacial procedures; and the usability of the technique in growing individuals. Disadvantages of DOG are: the sofar limited experience and follow-up in craniomaxillofacial surgery; and the unknown influences on growth. The technique will gradually find its niche and the general dentist will therefore be increasingly confronted with its specific indications. In this paper the general principles of DOG and a number of indications in craniomaxillofacial surgery are discussed.
Ugincius, Paulius; Kubilius, Ricardas; Gervickas, Albinas; Vaitkus, Saulius
The aim of the present study was to estimate average age of the patients in both sexes treated for MS, distribution by sex, amount of dexter and sinister MS with and without the fistulas into the maxillary sinus, with and without the foreign-bodies, length of stay in the Department of Maxillofacial Surgery at Kaunas Hospital of University of Medicine during the period from 1999 till 2004. The retrospective data analysis of the patients' treated from chronic MS was made. 346 patients (213 females and 133 males) were treated for chronic MS. 55 cases of chronic dexter MS with a fistula into maxillary sinus, 98 cases of chronic dexter MS without a fistula, 45 cases of chronic sinister MS with a fistula, 112 cases chronic sinister MS without a fistula, 16 cases of foreign-bodies in dexter maxillary sinus, 20 cases of foreign-bodies in sinister maxillary sinus have been detected. The main age of the female was 46.6+/-15.0, the main age of the men was 42.1+/-14.4. Statictically significant difference in the age difference of the women and the men was found (p=0.0024). It was determined, that females diagnosed and treated with chronic MS were 1.6 times more than males during the period from 1999 till 2004 in Kaunas Hospital of University of Medicine. Females treated for chronic MS were 4.5 years older than males.
... National Highway Traffic Safety Administration Distracted Driving Grant Program AGENCY: National Highway... Transportation (DOT) announced the availability of funding authorized for distracted driving grants on August 24... Progress in the 21st Century Act'' (MAP-21), Public Law 112-141, which created a new distracted...
Ralls, Matthew W.; Sueyoshi, Ryo; Herman, Richard S.; Utter, Brent; Czarnocki, Isabel; Si, Nancy; Luntz, Jonathan; Brei, Diann; Teitelbaum, Daniel H.
Background Distraction-induced enterogenesis, whereby the intestine lengthens with application of linear forces, is an emerging area which may provide a unique treatment for short bowel syndrome (SBS). With an increase in overall tissue mass, there is an increase in oxygen and nutrient demand. We hypothesized that a neovascularization within the mesentery is necessary to support the growing small bowel. Methods A curvilinear hydraulic device was used to induce growth within the small bowel of Yorkshire pigs, and the intestine was harvested after 14 days. High-resolution, gross pictures were recorded of the mesentery at implantation and at harvest, and CT imaging of the bowel and mesentery was performed at harvest after dye injection. Results After 2 weeks of distraction, an average of 72.5% (8.7cm) bowel lengthening was achieved. Gross images of the mesentery between major vessels showed a blossoming of the microvasculature and this was confirmed by CT imaging with 3D reconstruction. Mesenteric sample taken from the distracted segment had a 4-fold increase in the volume of microvasculature versus controls. Conclusion Enterogenesis results not only in increased bowel length, but significant increase in the mesenteric microvascularity. Presumably, this sustains the lengthened segment after application of longitudinal forces. PMID:23229341
Demehri, Farokh R.; Utter, Brent; Freeman, Jennifer J.; Fukatsu, Yumi; Luntz, Jonathan; Brei, Diann; Teitelbaum, Daniel H.
Purpose Previous methods of distraction enterogenesis have relied upon blind-ending intestinal segments or transmural device fixation, requiring multiple operations and potential bowel injury. We hypothesized that using a novel attachment would allow reversible device coupling to the luminal bowel surface, achieving effective endoluminal distraction. Methods A telescopic hydraulic device was designed with latex balloon attachments covered with high-friction mesh and a dilating fenestrated elastic mask (DFM attachment), allowing mesh-to-mucosa contact only with inflation. Yorkshire pigs underwent jejunal Roux-en-Y limb creation and device placement via jejunostomy. Devices underwent 3 cycles of balloon inflation and hydraulic extension/retraction per day for 7 days and then explanted and studied for efficacy. Results DFM attachment allowed reversible, high-strength endoluminal coupling without tissue injury or reduction in bowel perfusion. After 7 day implant, distracted bowel achieved a 44±2% increase in length vs. fed, non-distracted bowel, corresponding to a gain of 7.1±0.3 cm. Distracted bowel demonstrated increased epithelial cell proliferation vs. control bowel. Attachment sites demonstrated villus flattening, increased crypt depth, thicker muscularis mucosa, and unchanged muscularis propria thickness vs. control. Conclusion Novel high-strength, reversible attachments enabled fully endoluminal distraction enterogenesis, achieving length gains comparable to open surgical techniques. This approach may allow development of clinically applicable technology for SBS treatment. PMID:26552895
Kircher, Katja; Ahlstrom, Christer
Behavioral variables are often used as performance indicators (PIs) of visual or internal distraction induced by secondary tasks. The objective of this study is to investigate whether visual distraction can be predicted by driving performance PIs in a naturalistic setting. Visual distraction is here defined by a gaze based real-time distraction detection algorithm called AttenD. Seven drivers used an instrumented vehicle for one month each in a small scale field operational test. For each of the visual distraction events detected by AttenD, seven PIs such as steering wheel reversal rate and throttle hold were calculated. Corresponding data were also calculated for time periods during which the drivers were classified as attentive. For each PI, means between distracted and attentive states were calculated using t-tests for different time-window sizes (2 - 40 s), and the window width with the smallest resulting p-value was selected as optimal. Based on the optimized PIs, logistic regression was used to predict whether the drivers were attentive or distracted. The logistic regression resulted in predictions which were 76 % correct (sensitivity = 77 % and specificity = 76 %). The conclusion is that there is a relationship between behavioral variables and visual distraction, but the relationship is not strong enough to accurately predict visual driver distraction. Instead, behavioral PIs are probably best suited as complementary to eye tracking based algorithms in order to make them more accurate and robust.
Kircher, Katja; Ahlstrom, Christer
Behavioral variables are often used as performance indicators (PIs) of visual or internal distraction induced by secondary tasks. The objective of this study is to investigate whether visual distraction can be predicted by driving performance PIs in a naturalistic setting. Visual distraction is here defined by a gaze based real-time distraction detection algorithm called AttenD. Seven drivers used an instrumented vehicle for one month each in a small scale field operational test. For each of the visual distraction events detected by AttenD, seven PIs such as steering wheel reversal rate and throttle hold were calculated. Corresponding data were also calculated for time periods during which the drivers were classified as attentive. For each PI, means between distracted and attentive states were calculated using t-tests for different time-window sizes (2 – 40 s), and the window width with the smallest resulting p-value was selected as optimal. Based on the optimized PIs, logistic regression was used to predict whether the drivers were attentive or distracted. The logistic regression resulted in predictions which were 76 % correct (sensitivity = 77 % and specificity = 76 %). The conclusion is that there is a relationship between behavioral variables and visual distraction, but the relationship is not strong enough to accurately predict visual driver distraction. Instead, behavioral PIs are probably best suited as complementary to eye tracking based algorithms in order to make them more accurate and robust. PMID:21050615
Deniz, Y; Zengin, A Z; Karli, R
Foreign bodies in paranasal sinuses are very rare and most of them are encountered in the maxillary sinus. These foreign bodies may be organic or inorganic and can enter the maxillary sinus through an oro-antral fistula. The oro-antral fistula is formed by a break in the bony segment of the maxillary sinus floor and usually arises subsequent to maxillary premolar and molar extractions. A 63-year-old female patient evaluated for a nonhealing, left, toothless palate lesion and chronic headache occurring over 4 years. Radiography and computed tomography revealed bone discontinuity in the left floor of the maxillary sinus and calcifications within the antrum. A blue foreign body, later identified as dental impression material, was removed by intranasal endoscopy. A careful oral examination is recommended prior to prosthetic restorations. In addition, paranasal sinus foreign bodies should be surgically removed to prevent secondary soft tissue reactions.
Forster, Sophie; Lavie, Nilli
Attention may be distracted from its intended focus both by stimuli in the external environment and by internally generated task-unrelated thoughts during mind wandering. However, previous attention research has focused almost exclusively on distraction by external stimuli, and the extent to which mind wandering relates to external distraction is…
Oliveira, T F M; Pereira-Filho, V A; Gabrielli, M A C; Gonçales, E S; Santos-Pinto, A
This study aimed to assess the potential effects of two different osteotomy designs of the maxillary lateral wall on dental and skeletal changes after surgically assisted rapid maxillary expansion (SARME). Thirty adult patients were divided into two groups according to the lateral osteotomy design: group 1 (n=16) underwent lateral osteotomy performed in a horizontal straight fashion, and group 2 (n=14) underwent lateral osteotomy performed in parallel to the occlusal plane with a step at the zygomatic buttress. Cone beam computed tomography scans were obtained preoperatively (T1), immediately after expansion (T2), and 6 months after expansion (T3). Mixed analysis of variance (ANOVA) was used for the statistical analysis. The results showed no significant interaction effect between groups and time points. Therefore, maxillary expansion was effective in both groups. Statistically significant increases in all dental and skeletal measurements were observed immediately after expansion (P<0.001). Relapse of the nasal floor width, tipping of the supporting teeth, and an increase in root distance in molars occurred at T3 (P<0.05). In summary, the maxillary lateral osteotomy design did not influence the results of SARME, which occurred mainly through the inclination of maxillary segments.
Pingarrón-Martín, Lorena; Otero, T. González; Gallo, L.J. Arias
The goal of transport-disc-distraction osteogenesis (TDDO) is to restore bone continuity by using in-situ bone. It may be useful following trauma, gunshot injuries, or tumor ablation, especially when there may be contraindications at the donor site or for prolonged surgery. To the best of the authors' knowledge, this is the first time TDDO has been used for mandibular reconstruction reporting additional procedures, which include osseointegrated dental implants rehabilitation and orthognathic surgery. A retrospective study is performed analyzing all mandibular reconstruction cases that may be suitable for distraction from January 2006 to December 2011. A thorough description of the documented cases includes details about sex, gender, complications, duration of hospitalization, etiology, size, and location of the defect. Eight cases of mandibular reconstruction were included. Six cases correspond to mandibular ameloblastoma. The remaining two cases were mandibular gunshot comminuted fractures. Range of the defects was from 45 to 60 mm. Length of the transport disc was 15 to 20 mm. Protocolized technique consisted of 5 days of latency period, 19 to 45 days of activation term (average 30 days), and 8 to 12 weeks for consolidation. Mean distraction length achieved was 40.45 mm. We can conclude that TDDO is an alternative to conventional and more invasive procedures, when we face severe segmental mandibular defects reconstruction. It shows the potential to restore a better anatomical bone regeneration, also providing soft tissues and reducing donor-site morbidity. Patients' education and awareness about the proper use of the transport-disc-distraction device is important to optimize functional outcomes. PMID:26000082
Noorollahian, Saeed; Alavi, Shiva; Shirban, Farinaz
ABSTRACT Objective: The aim of this study was to introduce a new method for bilateral distal movement of the entire maxillary posterior segment. Case report: A 17-year-old girl with Class I skeletal malocclusion (end-to-end molar relationships, deviated midline and space deficiency for left maxillary canine) was referred for orthodontic treatment. She did not accept maxillary first premolars extraction. A modified Hyrax appliance (Dentaurum Ispringen, Germany) was used for bilateral distalization of maxillary posterior teeth simultaneously. Expansion vector was set anteroposteriorly. Posterior legs of Hyrax were welded to first maxillary molar bands. All posterior teeth on each side consolidated with a segment of 0.017 × 0.025-in stainless steel wire from the buccal side. Anterior legs of Hyrax were bent into eyelet form and attached to the anterior palate with two mini-screws (2 × 10 mm) (Jeil Medical Corporation Seoul, South Korea). Hyrax opening rate was 0.8 mm per month. Lateral cephalometric radiographs were used to evaluate the extent of distal movement. 3.5-mm distalization of posterior maxillary teeth was achieved in five months. Results: A nearly bodily distal movement without anchorage loss was obtained. Conclusion: The mini-screw-supported modified Hyrax appliance was found to be helpful for achieving en-masse distal movement of maxillary posterior teeth. PMID:27409657
Hamza, Karim M.
In this article, I make a case for the potential educative worth of distractions for learning science in the school laboratory. Distractions are operationalized as experiences lying outside the main purpose of the laboratory activity, thereby diverting students' attention from that purpose. Through a practical epistemology analysis, I…
Renon, P; Casanova, M; Verdier, M; Asperge, A; Le Mouel, C
Suppurated maxillary sinusitis are frequent diseases. Diameatic puncture allows bacteriological investigations. Our results are positive in two thirds of cases. The bacterial flora is very varied, whose identification and antibiograms involve efficient treatment with daily washing and in situ antibiotherapy.
Kshar, Avinash; Patil, Abhijeet; Umarji, Hemant; Kadam, Sonali
Mucoceles are defined as chronic, cystic lesions in the paranasal sinuses. When the mucocele content becomes infected, the lesion is defined as mucopyocele. Most mucoceles are located in the frontal and anterior ethmoid sinuses and normally they involve the frontal-ethmoid complex, expanding to the superior-medial region of the orbit, leading to ocular disorders; maxillary sinus presentation is rare. In the present article, the authors described a rare case of mucopyocele in the maxillary sinus. PMID:24688571
Subramaniam, Shiva S.; Vujcich, Nathan J.; Nastri, Alf L.
Summary: Vascularized free flaps have become the gold standard in reconstructing large segmental mandibular defects; however, even when bony union and soft-tissue coverage is achieved, insufficient bone stock and altered facial contour can create functional and cosmetic problems for the patient. There have been limited case reports on the use of secondary distraction osteogenesis to address these issues. The authors report a case of bilateral mandibular distraction of deep circumflex iliac artery free flaps, used for mandibular reconstruction after total mandibulectomy for treatment of osteosarcoma. Performed for reasons of retrognathia and facilitation of dental prosthetic rehabilitation, this is the first case of bilateral horizontal distraction osteogenesis of deep circumflex iliac artery free flaps reported in the literature. PMID:27257565
Durbin, Dennis R; McGehee, Daniel V; Fisher, Donald; McCartt, Anne
Novice teen drivers have long been known to have an increased risk of crashing, as well as increased tendencies toward unsafe and risky driving behaviors. Teens are unique as drivers for several reasons, many of which have implications specifically in the area of distracted driving. This paper reviews several of these features, including the widespread prevalence of mobile device use by teens, their lack of driving experience, the influence of peer passengers as a source of distraction, the role of parents in influencing teens’ attitudes and behaviors relevant to distracted driving and the impact of laws designed to prevent mobile device use by teen drivers. Recommendations for future research include understanding how engagement in a variety of secondary tasks by teen drivers affects their driving performance or crash risk; understanding the respective roles of parents, peers and technology in influencing teen driver behavior; and evaluating the impact of public policy on mitigating teen crash risk related to driver distraction. PMID:24776228
Yen, S L
Distraction osteogenesis is a surgical-orthopedic method for lengthening bone by separating or distracting a fracture callus. This technique has a long history in limb lengthening and has recently been used to lengthen mandibles and maxillae in human patients. Distraction osteogenesis represents a powerful method of producing unlimited quantities of living bone which can be formed along any plane of space. Because this method uses local host tissue, it offers many advantages over bone grafting. In the author's experience, large (10-22 mm) antero-posterior and vertical corrections of mandibles can be achieved using this technique. The purpose of this article is to review its biological basis and discuss recent clinical applications. This article reviews the history, theory, current management, and limitations of distraction osteogenesis in treating craniofacial anomalies.
Kotlow, Lawrence A
Successful breastfeeding is dependent upon an infant's ability to correctly latch onto a mother's breast. If an infant is born with oral soft tissue abnormalities such as tongue-tie or lip-tie, breastfeeding may become challenging or impossible. During the oral evaluation of an infant presenting with breastfeeding problems, one area that is often overlooked and undiagnosed and, thus, untreated is the attachment of the upper lip to the maxillary gingival tissue. Historically, this tissue has been described as the superior labial frenum, median labial frenum, or maxillary labial frenum. These terms all refer to a segment of the mucous membrane in the midline of the upper lip containing loose connective tissue that inserts into the maxillary arch's loose, unattached gingival or tight, attached gingival tissue. There is no muscle contained within this tissue. In severe instances, this tissue may extend into the area behind the upper central incisors and incisive papilla. The author has defined and identified the restrictions of mobility of this tissue as a lip-tie, which reflects the clinical attachment of the upper lip to the maxillary arch. This article discusses the diagnosis and classifications of the lip-tie, as it affects an infant's latch onto the mother's breast. As more and more women choose to breastfeed, lip-ties must be considered as an impediment to breastfeeding, recognizing that they can affect a successful, painless latch and milk transfer.
Minagi, S; Sakiya, M; Sato, T; Matsunaga, T; Natsuaki, N
Mechanical static traction has been adopted as one of the treatment procedures for joint diseases and fractures. The effect of mechanical vibration on the mechanical traction of the temporomandibular joint was studied in six human subjects. A mechanical traction force of 2000 gf was applied as a dynamic traction force with mechanical vibration or as a static traction force. The dynamic traction force with vibration was applied for 5 min to the right temporomandibular joint using a vibrating-traction apparatus which generated mechanical vibrations of 1000, 3000 or 4000 Hz. Application of a static traction force for 5 min was used as a control condition. Vertical condylar displacement was mathematically evaluated from the deviation of the mandible using Eddy current displacement sensors which were attached to the maxillary dental arch. Among the three vibration frequencies, 3000 Hz resulted in the maximum vertical condylar displacement for all six subjects, showing the mean condylar displacement of 668+/-242 microm. In contrast, vibrations of 1000 and 4000 Hz showed a smaller traction effect. Application of the static traction force for 5 min resulted in a mean vertical condylar displacement of 5.7+/-4.9 microm, showing almost no traction effect to the joint. From the results of this study, it was revealed that vibrating traction could distract a joint more effectively than could static traction and that the traction force necessary for effective vibrating traction was less than that for static traction.
G.A. Ilizarov's clinical insights and experimental biology have developed into what is known today as distraction osteogenesis. Initially used for the treatment of fractures and nonunions, his methods have proven successful for limb lengthening and bone transportation. A brief history of the development of distraction osteogenesis, definition of terms, methods, and monitoring techniques are described. The primary mechanism, intramembranous ossification, is direct bone formation in uniform gradients of mineralization from a central fibrous interzone. New bone is produced from the local host surfaces and quickly remodels to the equivalent macro and microstructure. Blood supply at the focus of distraction, dependency on a latency period, different rates, and rhythms of distraction are all tested and discussed. Data from experimental tibial lengthening in more than 125 animals (dogs, rabbits, and rats) show that distraction osteogenesis provides unlimited new bone formation that remodels at daily rates ranging from 200 to 400 microns. In over 100 clinical cases, patients ranging in age from 18 months to 49 years have regenerated bone at an average rate of 213 microns in adults and 385 microns in children. Approximately 10% of these cases required supplemental bone grafts. The article proposes that distraction osteogenesis might be successfully applied in craniofacial surgery.
Pacheco-Unguetti, Antonia P; Parmentier, Fabrice B R
Research shows that attention is ineluctably captured away from a focal visual task by rare and unexpected changes (deviants) in an otherwise repeated stream of task-irrelevant auditory distractors (standards). The fundamental cognitive mechanisms underlying this effect have been the object of an increasing number of studies but their sensitivity to mood and emotions remains relatively unexplored despite suggestion of greater distractibility in negative emotional contexts. In this study, we examined the effect of sadness, a widespread form of emotional distress and a symptom of many disorders, on distraction by deviant sounds. Participants received either a sadness induction or a neutral mood induction by means of a mixed procedure based on music and autobiographical recall prior to taking part in an auditory-visual oddball task in which they categorized visual digits while ignoring task-irrelevant sounds. The results showed that although all participants exhibited significantly longer response times in the visual categorization task following the presentation of rare and unexpected deviant sounds relative to that of the standard sound, this distraction effect was significantly greater in participants who had received the sadness induction (a twofold increase). The residual distraction on the subsequent trial (postdeviance distraction) was equivalent in both groups, suggesting that sadness interfered with the disengagement of attention from the deviant sound and back toward the target stimulus. We propose that this disengagement impairment reflected the monopolization of cognitive resources by sadness and/or associated ruminations. Our findings suggest that sadness can increase distraction even when distractors are emotionally neutral.
Xiao, Yao; Shi, Jing
This paper aims to study the traffic flow characteristics considering drivers’ distraction behavior, which is common and lasts for stochastic duration time. The distribution of distraction duration time and the influence of distraction on traffic flow are analyzed. The relationship among distraction duration time, probability of distraction occurrence and proportion of distraction is established by stochastic model. Then a modified optimal velocity model was proposed to simulate a two-lane road, taking the effect of distraction behavior into account. A survey was conducted to collect maximum speed, average speed, lane change frequency and headway of vehicle when distracted. The results suggest that distraction behavior has significant negative influence on traffic flow rate and increases the lane changing frequency. Short-time distraction seems to have smaller impact on traffic flow than long-time distraction. This model simulates the distraction behavior very well and distracted drivers have lower mean speed, lower lane changing frequency, longer headway and are overtaken by more vehicles in simulation. This study provided a good model to analyze distraction behavior in traffic flow and pointed out an important factor affecting the traffic flow efficiency.
Kanthem, Ranjith Kumar; Guttikonda, Venkateswara Rao; Yeluri, Sivaranjani; Kumari, Geetha
Background: Individual identification is a subtle concept and often one of the most important priorities in mass disasters, road accidents, air crashes, fires, and even in the investigation of criminal cases. Matching specific features detected on the cadaver with data recorded during the life of an individual is an important aspect in forensics, and can be performed by fingerprint analysis, deoxyribonucleic acid matching, anthropological methods, radiological methods and other techniques which can facilitate age and sex identification. Sinus radiography is one such method that has been used for determination of the sex of an individual. Hence, an attempt is being made to use the different dimensions of the maxillary sinus in the determination of sex using coronal and axial sections of plain computed tomography (CT) scan. Materials and Methods: A total of 30 patients including 17 male and 13 female, visiting the Outpatient Department of the Mamata General Hospital were included as the study subjects. The dimensions of right and left maxillary sinuses of 30 subjects from plain CT were measured using SYNGO software and statistical analysis was done. Results: Sex determination using height, length, width, and volume of the maxillary sinus on both sides showed statistically significant results with a higher percentage of sexual dimorphism in the case of volume. Conclusion: Volume of the right maxillary sinus can be used as accurate diagnostic parameter for sex determination. PMID:26005308
Ahn, Hyo-Won; Seo, Dong Hwi; Kim, Seong-Hun; Lee, Baek-Soo; Chung, Kyu-Rhim; Nelson, Gerald
Although 2-jaw orthognathic surgery is a typical recommendation for the treatment of facial asymmetry, another good treatment alternative is maxillary corticotomy with temporary skeletal anchorage devices followed by mandibular orthognathic surgery. The corticotomy procedure described here can achieve unilateral molar intrusion and occlusal plane canting correction with potentially fewer complications than 2-jaw orthognathic surgery. The approach allows movement of dentoalveolar segments in less time than with conventional dental intrusion using temporary skeletal anchorage devices. A 2-jaw asymmetry with occlusal plane canting might be corrected using maxillary corticotomy and mandibular orthognathics rather than 2-jaw orthognathics. Two patients with facial asymmetry are presented here. In each one, the maxillary cant was corrected over a period of 2 to 3 months with 3.5 mm of intrusion of the unilateral buccal segment. After the preorthognathic cant correction, orthognathic surgery was done to correct the mandibular asymmetry.
Pacheco-Unguetti, Antonia Pilar; Parmentier, Fabrice B R
Rare and unexpected changes (deviants) in an otherwise repeated stream of task-irrelevant auditory distractors (standards) capture attention and impair behavioural performance in an ongoing visual task. Recent evidence indicates that this effect is increased by sadness in a task involving neutral stimuli. We tested the hypothesis that such effect may not be limited to negative emotions but reflect a general depletion of attentional resources by examining whether a positive emotion (happiness) would increase deviance distraction too. Prior to performing an auditory-visual oddball task, happiness or a neutral mood was induced in participants by means of the exposure to music and the recollection of an autobiographical event. Results from the oddball task showed significantly larger deviance distraction following the induction of happiness. Interestingly, the small amount of distraction typically observed on the standard trial following a deviant trial (post-deviance distraction) was not increased by happiness. We speculate that happiness might interfere with the disengagement of attention from the deviant sound back towards the target stimulus (through the depletion of cognitive resources and/or mind wandering) but help subsequent cognitive control to recover from distraction.
Vissink, A; de Baat, C
Distraction osteogenesis is a treatment in which new bone is created in the space which comes to exist between bone fragments that have slowly been driven apart by osteogenesis. This treatment, originally developed in orthopaedic surgery, is also commonly used for correcting deformities in the head and neck. After an initial hype, during which time distraction osteogenesis was used to correct deformities in the maxillofacial skeleton, it is beginning to become clearer for which conditions in the head and neck region distraction osteogenesis is most effective or can be seen as a good alternative for 'classical' surgical treatment. In this special issue, the application of distraction osteogenesis in orthopaedics, pre-prosthetic reconstructive surgery, orthodontics and cleft-surgery are discussed and the mandible, the maxilla and the cranio-facial skeleton are also considered. In addition, the possibility that the consolidation period can be reduced in the case of some treatments, such as bone substitutes and growth factors, by combining them with distraction osteogenesis is also addressed.
Tavakoli, K; Stewart, K J; Poole, M D
Distraction osteogenesis is a technique of new bone formation by the gradual separation of bony fragments. The method, although initially developed for limb lengthening, is now being applied in the treatment of craniofacial deformities. A number of principles have been established through careful scientific study to guide clinical practice, such as the ideal rate and rhythm of distraction, the need for periosteal preservation during bone division, a "latent period" of neutral fixation before, and a "consolidation period" after distraction. The technique is being applied in craniofacial surgery particularly for mandibular deformities and offers considerable advantages over previous methods such as osteotomy and inlay bone grafting. Donor site morbidity is avoided, the investing soft tissue envelope is concurrently expanded, and the magnitude of the procedure is less. However, the technique is still in its infancy and requires further modification and refinement before widespread acceptance as a treatment in mainstream craniofacial surgery. Problems with cutaneous scarring and socially undesirable external hardware, particularly in the pediatric population, have led to the emergence of intraoral miniature devices, with the ultimate goal of development of a multiplanar internal autodistractor. Furthermore, many principles well established in leg lengthening, such as the rate and rhythm of distraction, need to be reexamined and the parameters redefined with particular reference to the craniofacial skeleton. Distraction osteogenesis has an expanding role in craniofacial surgery.
Chang, Catherine S; Swanson, Jordan; Yu, Jason; Taylor, Jesse A
Traditionally, maxillary hypoplasia in the setting of cleft lip and palate is treated via orthognathic surgery at skeletal maturity, which condemns these patients to abnormal facial proportions during adolescence. The authors sought to determine the safety profile of computer-aided design/computer-aided modeling (CAD/CAM) planned, Le Fort I distraction osteogenesis with internal distractors in select patients presenting at a young age with severe maxillary retrusion. The authors retrospectively reviewed our "early" Le Fort I distraction osteogenesis experience-patients performed for severe maxillary retrusion (≥12 mm underjet), after canine eruption but prior to skeletal maturity-at a single institution. Patient demographics, cleft characteristics, CAD/CAM operative plans, surgical complications, postoperative imaging, and outcomes were analyzed. Four patients were reviewed, with a median age of 12.8 years at surgery (range 8.6-16.1 years). Overall mean advancement was 17.95 + 2.9 mm (range 13.7-19.9 mm) with mean SNA improved 18.4° to 87.4 ± 5.7°. Similarly, ANB improved 17.7° to a postoperative mean of 2.4 ± 3.1°. Mean follow-up was 100.7 weeks, with 3 of 4 patients in a Class I occlusion with moderate-term follow-up; 1 of 4 will need an additional maxillary advancement due to pseudo-relapse. In conclusion, Le Fort I distraction osteogenesis with internal distractors is a safe procedure to treat severe maxillary hypoplasia after canine eruption but before skeletal maturity. Short-term follow-up demonstrates safety of the procedure and relative stability of the advancement. Pseudo-relapse is a risk of the procedure that must be discussed at length with patients and families.
Oh, Chang-Wug; Shetty, Gautam M; Song, Hae-Ryong; Kyung, Hee-Soo; Oh, Jong-Keon; Min, Woo-Kie; Lee, Byung-Woo; Park, Byung-Chul
Although distraction osteogenesis has solved limb length discrepancies, many complications are inevitable from long duration of external fixation. Use of intramedullary nails for early removal of fixators has its own challenges especially in pediatric age group. To facilitate early removal of external fixators in children, we tried a novel method of submuscular plating over the distraction callus, which is described, and the results and complications of this technique are presented. In eight children (four girls and four boys), of limb lengthening (four cases) and bone transport (four cases) done in three femurs and five tibiae with external fixators (five Ilizarov ring fixators and three monofixators), submuscular plating was done over the distraction callus. The causes of limb length discrepancy included traumatic and septic growth arrest, congenital pseudoarthrosis of tibia, fibular hemimelia, tumor salvage, and Perthes' disease. The purpose of plating was to remove the external fixator earlier after achieving the target length. Mean age of plating procedure was 11.62 years, and mean amount of distraction was 5.47 cm. In all patients, the distraction callus healed on maintaining its length or correcting into the original alignment. The mean external fixation index was 26.93 days/cm and healing index was 52.01 days/cm. One complication of superficial pin-track infection occurred, which resolved completely with conservative treatment. None of the patients developed deep infection or implant failures. The mean follow-up after plating was 28 months (range, 18-62 months). Submuscular plating over the distraction callus may be a successful method that permits early removal of fixator with fewer complications. This method can be a useful alternative in children or when nailing is difficult.
Background Oral breathing and maxillary deficiency are often associated with steep mandibular plane angle, and retrognathic mandible compared with the faces of healthy controls. Some studies suggested that after rapid maxillary expansion, improvement in nasal breathing and repositioning of mandible with transitory increasing of facial height and, in some cases, spontaneous forward repositioning might occur. The abovementioned mandibular effects could contribute to enlarge oropharynx volume with repositioning of tongue and soft palate with an improvement of upper airway volume after treatment. The aim of this study was to investigate by cone beam computed tomography the role of oropharyngeal volume and mandibular position changes after rapid maxillary expansion in patients showing improved breathing pattern confirmed by polysomnography exam. Methods The final sample of this retrospective study comprised 14 Caucasian patients (mean age 7.6 years) who undergone rapid maxillary expansion with Haas-type expander banded on second deciduous upper molars. Cone beam computed tomography scans and polysomnography exams were collected before placing the appliance (T0) and after 12 months (T1). Mandibular landmarks localization and airway semiautomatic segmentation on cone beam computed tomography scans allowed airway volume computing and measurements. Results No significant differences were found between oropharyngeal airway changes and mandibular displacement after rapid maxillary expansion in growing patients. Conclusions The suggested improvement in upper airway and breathing after rapid maxillary expansion should be further related to different compartments of airway such as rhinopharynx and nasal cavity. PMID:24934328
Zapata, Uriel; Halvachs, Emily K; Dechow, Paul C; Elsalanty, Mohammed E; Opperman, Lynne A
Reconstruction of the canine mandible using bone transport distraction osteogenesis has been shown to be a suitable method for correcting segmental bone defects produced by cancer, gunshots, and trauma. Although the mechanical quality of the new regenerate cortical bone seems to be related to the mineralization process, several questions regarding the microstructural patterns of the new bony tissue remain unanswered. The purpose of this study was to quantify any microstructural differences that may exist between the regenerate and control cortical bone. Five adult American foxhound dogs underwent unilateral bone transport distraction of the mandible to repair bone defects of 30-35 mm. Animals were killed 12 weeks after the beginning of the consolidation period. Fourteen cylindrical cortical samples were extracted from the superior, medial, and inferior aspects of the lingual and buccal plates of the reconstructed aspect of the mandible, and 21 specimens were collected similarly from the contralateral aspect of the mandible. Specimens were evaluated using histomorphometric and micro-computed tomographic techniques to compare their microstructure. Except for differences in haversian canal area, histomorphometric analyses suggested no statistical differences in microstructure between regenerate and control cortical bone. Morphological evaluation suggested a consistent level of anisotropy, possibly related to the distraction vector. After 12 weeks' consolidation, bone created during bone transport distraction osteogenesis was comparable to native bone in microstructure, architecture, and mechanical properties. It is proposed that, after enough time, the properties of the regenerate bone will be identical to that of native bone.
Catagni, Maurizio A; Guerreschi, Francesco; Lovisetti, Luigi
Bone regeneration obtained by distraction osteogenesis is influenced by a series of factors. These include factors that are related to the mechanical stability of the system of distraction (internal or external devices), and to factors directly depending on the biology of the bone tissue, such as the method of bone interruption (osteotomy), the delay and rhythm of distraction, the anatomical site of the osteotomy, and the histological characteristics of the bone requiring reconstruction. The stability of the system of bone fixation depends on the rigidity of the frame, the connexion of the apparatus to the bone (wires, pins) and the intrinsic stability of the segment (length and level of maturation of bone regenerate). The radiological characteristics of bone regeneration (hypo- or hypertrophy) lead to the adaptation of the rhythm of distraction. Following more than 28 years of experience of application of the Ilizarov method for bone reconstruction, the authors describe the technique of frame assembly and the methods of evaluation and treatment of the complications of new bone formation.
Delloye, C; Delefortrie, G; Coutelier, L; Vincent, A
The aim of this study was to delineate the pattern of bone regeneration from cortical bone segments during distraction lengthening. The lengthening procedure was applied for various periods through the Ilizarov system on the forearms of mature dogs. Bone was sectioned either by corticotomy, preserving the nutrient artery integrity, or by osteotomy. When an osteotomy was performed, the marrow cavity was in some cases plugged with either resorbable bone wax or nonresorbable material. Under distraction, both periosteal and medullary callus on either side of the gap gave rise to new bone trabeculae. The trabeculae on either side were oriented along the direction of distraction and progressively approached one another. This striated callus emerging from both sides was the most characteristic pattern of bone regeneration subsequent to distraction lengthening. Fusion was achieved approximately four weeks after the end of the lengthening period. Most of the new bone was formed by membranous ossification; some cartilaginous nodules developed. Corticalization of the bone trabeculae that had begun at three months was not fully achieved at five months after the lengthening period. There were no differences found in the pattern of bone healing and the amount of newly formed bone after corticotomy or osteotomy with or without resorbable bone wax plugging.
Morcos, Mina W.; Al-Jallad, Hadil; Hamdy, Reggie
Bone is one of the most dynamic tissues in the human body that can heal following injury without leaving a scar. However, in instances of extensive bone loss, this intrinsic capacity of bone to heal may not be sufficient and external intervention becomes necessary. Several techniques are available to address this problem, including autogenous bone grafts and allografts. However, all these techniques have their own limitations. An alternative method is the technique of distraction osteogenesis, where gradual and controlled distraction of two bony segments after osteotomy leads to induction of new bone formation. Although distraction osteogenesis usually gives satisfactory results, its major limitation is the prolonged duration of time required before the external fixator is removed, which may lead to numerous complications. Numerous methods to accelerate bone formation in the context of distraction osteogenesis have been reported. A viable alternative to autogenous bone grafts for a source of osteogenic cells is mesenchymal stem cells from bone marrow. However, there are certain problems with bone marrow aspirate. Hence, scientists have investigated other sources for mesenchymal stem cells, specifically adipose tissue, which has been shown to be an excellent source of mesenchymal stem cells. In this paper, the potential use of adipose stem cells to stimulate bone formation is discussed. PMID:26448947
Karun, Vinayak; Agarwal, Navneet; Singh, Virendra
Introduction: Management of mandibular deformities is challenging. Distraction osteogenesis is a relatively new technique with promising results. Materials and Methods: We selected 12 patients. The osteotomy site decided was proximal to the antegonial notch. Latency time was five to seven days. Consolidation period was eight weeks in eleven cases and six weeks in one case. Results: In all the patients, appreciable lengthening of mandible was achieved. Discussion: The greatest advantage of distraction osteogenesis is growth of soft tissue along with the growth of hard tissue. This increases post operative stability PMID:24665178
Wong, Lily Y. S.
This paper identifies distracting factors which take away pupils' attention from the lesson and focus it on the teacher. Distracting factors include teachers' irritating habits, improper attire, and mannerisms. Examples of distracting features of both males and females are listed in eight categories: (1) attire; (2) hair; (3) make-up; (4) personal…
Ozawa, Sachiyo; Hiraki, Kazuo
When near-infrared spectroscopy (NIRS) is used to measure emotion-related cerebral blood flow (CBF) changes in the prefrontal cortex regions, the functional distinction of CBF changes is often difficult because NIRS is unable to measure neural activity in deeper brain regions that play major roles in emotional processing. The CBF changes could represent cognitive control of emotion and emotional responses to emotional materials. Supposing that emotion-related CBF changes in the prefrontal cortex regions during distraction are emotional responses, we examined whether oxygenated hemoglobin (oxyHb) decreases. Attention-demanding tasks cause blood flow decreases, and we thus compared the effects of visually paced tapping with different tempos, on distraction. The results showed that the oxyHb level induced by emotional stimulation decreased with fast-tempo tapping significantly more than slow-tempo tapping in ventral medial prefrontal cortex regions. Moreover, a Global-Local task following tapping showed significantly greater local-minus-global response time (RT) difference scores in the fast- and mid-tempo condition compared with those in the slow-tempo, suggesting an increased attentional focus, and decreased negative emotion. The overall findings indicate that oxyHb changes in a relatively long distraction task, as measured by NIRS, are associated with emotional responses, and oxyHb can be decreased by successfully performing attention-demanding distraction tasks.
Choi, In Ho; Chung, Chin Youb; Cho, Tae-Joon; Yoo, Won Joon
Distraction osteogenesis is currently a standard method of bone lengthening. It is a viable method for the treatment of short extremities as well as extensive bone defects, because large amounts of bone can be regenerated in the distraction gap. Mechanical stimulation by distraction induces biological responses of skeletal regeneration that is accomplished by a cascade of biologic processes that may include differentiation of pluripotential tissue, angiogenesis, mineralization, and remodeling. There are complex interactions between bone-forming osteoblasts and other cells present within the bone microenvironment, particularly vascular endothelial cells that may be pivotal members of a complex interactive communication network in bone. Regenerate bone forms by three modes of ossification, which include intramembranous, enchondral, and transchondroid ossifications, although intramembraneous bone formation is the predominant mechanism of ossification. In this review we discussed the coupling between angiogenesis and mineralization, the biological and mechanical factors affecting them, the cellular and molecular events occurring during distraction osteogenesis, and the emerging modalities to accelerate regenerate bone healing and remodeling. PMID:12172035
Lee, John D.
Driver distraction research has a long history, spanning nearly 50 years, but intensifying over the last decade. The dominant paradigm guiding this research defines distraction in terms of excessive workload and limited attentional resources. This approach largely ignores how drivers come to engage in these tasks and under what conditions they engage and disengage from driving—the dynamics of distraction. The dynamics of distraction identifies breakdowns of interruption management as an important contributor to distraction, leading to describe distraction in terms of failures of task timing, switching, and prioritization. The dynamics of distraction also identifies disengagement in driving (e.g., mind wandering) as a substantial challenge that secondary tasks might exacerbate or mitigate. Increasing vehicle automation accentuates the need to consider these dynamics of distraction. Automation offers drivers more opportunity to engage in distractions and disengage from driving, and can surprise drivers by unexpectedly requiring drivers to quickly re-engage in driving—placing greater importance of interruption management expertise. This review describes distraction in terms of breakdowns in interruption management and problems of engagement, and summarizes how contingency, conditioning, and consequence traps lead to problems of engaging and disengaging in driving and distractions. PMID:24776224
Wang, Honghong; Feng, Jing; Lu, Peijun; Shen, Gang
To correct an Angle Class II malocclusion or to create spaces in the maxillary arch by nonextraction treatment, distal movement of the maxillary molars is required. Various modalities for distalizing the buccal segment have been reported. Conventional extraoral appliances can be used to obtain maximum anchorage. However, many patients reject headgear wear because of social and esthetic concerns, and the success of this treatment depends on patient compliance. Intraoral appliances, such as repelling magnets, nickel-titanium coils, pendulum appliance, Jones jig appliance, distal jet appliance, and modified Nance appliance, have been introduced to distalize the molars with little or no patient cooperation. However, intraoral appliances can result in anchorage loss of the anterior teeth and distal tipping of the maxillary molars. In this case report, we introduce a diversified rapid maxillary expansion appliance that was custom designed and fabricated for the treatment of a growing girl with a skeletal Class II malocclusion and severe crowding from a totally lingually positioned lateral incisor. The appliance concomitantly expanded the maxilla transversely and retracted the buccal segment sagittally, distalizing the maxillary molars to reach a Class I relationship and creating the spaces to displace the malpositioned lateral incisor. The uniqueness of this special diversified rapid maxillary expansion appliance was highlighted by a series of reconstructions and modifications at different stages of the treatment to reinforce the anchorage.
Young, Kristie L; Salmon, Paul M; Cornelissen, Miranda
This study explored the nature of errors made by drivers when distracted versus not distracted. Participants drove an instrumented vehicle around an urban test route both while distracted (performing a visual detection task) and while not distracted. Two in-vehicle observers recorded the driving errors made, and a range of other data were collected, including driver verbal protocols, forward, cockpit and driver video, and vehicle data (speed, braking, steering wheel angle, etc.). Classification of the errors revealed that drivers were significantly more likely to make errors when distracted; although driving errors were prevalent even when not distracted. Interestingly, the nature of the errors made when distracted did not differ substantially from those made when not distracted, suggesting that, rather than making different types of errors, distracted drivers simply make a greater number of the same error types they make when not distracted. Avenues for broadening our understanding of the relationship between distraction and driving errors are discussed along with the advantages of using a multi-method framework for studying driver behaviour.
Kulkarni, M V; Bonner, F M; Abdo, G J
A maxillary sinus hemangioma was detected as an incidental finding during magnetic resonance imaging of the head. The CT findings are more characteristic for the diagnosis of this lesion. Preoperative diagnosis of maxillary sinus hemangioma is important since these lesions can frequently cause a large amount of hemorrhage during surgery.
Cholesterol granuloma (CG) of the maxillary sinus is very rare. In this study, the searching of the literature was performed with the keywords of cholesterol granuloma and maxillary sinus. All retrieved literature were reviewed throughout to identify and analyze all individual characteristics. Two additional cases in our hospital were also included. The result showed that, in the overall 37 cases, the ratio of male to female was about 3:1. Caucasian (14/37) and Turkish (10/37) were reported more frequently. CG of maxillary sinus had an opposite sex predilection compared with the fungus balls of the maxillary sinus. In addition, the comorbidity of these two diseases was found only in one patient in the literature. These results suggested that the different mechanisms other than poor aeration of the maxillary sinus played a role in the formation of CG of maxillary sinus. The diagnosis for CG of the maxillary sinus before operation is difficult, but the clear golden yellow rhinorrhea and hemorrhagic signs may provide a good diagnostic evidence. The symptoms were vague and about half of the patients presented with non-specific symptoms. Therefore, it seemed reasonable that CG of the maxillary sinus was under diagnosed in the clinical practice. Treatment consists of complete excision via Caldwell-Luc or endoscopic approach and provides a good prognosis. Bilateral involvements are rare but possible in this disease entity.
Rowe, N M; Mehrara, B J; Dudziak, M E; Steinbreck, D S; Mackool, R J; Gittes, G K; McCarthy, J G; Longaker, M T
The application of distraction osteogenesis to craniofacial surgery has altered the approach and treatment of congenital and acquired craniofacial defects. Although the histologic and ultrastructural changes associated with distraction osteogenesis have been described extensively, relatively little is known about the molecular regulation of this process. The elucidation of the molecular mechanisms of distraction osteogenesis has important clinical implications because it may facilitate the use of recombinant proteins or gene therapy to accelerate bone regeneration. Molecular analysis of distraction osteogenesis has been hindered by the use of large animal models in which only limited genetic information is available. In this study, a rat model of mandibular distraction osteogenesis is described. This report includes a pilot study (n = 50) to develop an appropriate distraction device and to determine the optimal placement of the osteotomy. The study subsequently included 80 animals, 35 of which were distracted at a rate of 0.25 mm per day for 6 days (1.5 mm total) and 35 that were distracted at a rate of 0.25 mm twice per day (3.0 mm total). These animals were killed at various time points (after latency and during the distraction and consolidation periods) and displayed histologic and radiographic findings of membranous bone distraction osteogenesis that were consistent with those in large ,animal and clinical models. In addition, five animals each were acutely lengthened 1.5 mm and 3.0 mm and demonstrated a fibrous nonunion. Furthermore, the utility of this model is demonstrated in the analysis of the molecular mechanisms of distraction osteogenesis by applying the polymerase chain reaction to total cellular RNA isolated from normal and distracted rat mandibles. In conclusion, it is believed that the rat model of distraction osteogenesis has significant advantages over traditional models, including decreased costs and facilitation of molecular analysis.
Le, Peter; Hwang, Jaejin; Grawe, Sarah; Li, Jing; Snyder, Alison; Lee, Christina; Marras, William S
The objective of this study was to identify biomechanical measures that can distinguish texting distraction in a laboratory-simulated driving environment. The goal would be to use this information to provide an intervention for risky driving behaviour. Sixteen subjects participated in this study. Three independent variables were tested: task (texting, visual targeting, weighted and non-weighted movements), task direction (front and side) and task distance (close and far). Dependent variables consisted of biomechanical moments, head displacement and the length of time to complete each task. Results revealed that the time to complete each task was higher for texting compared to other tasks. Peak moments during texting were only distinguishable from visual targeting. Peak head displacement and cumulative biomechanical exposure measures indicated that texting can be distinguished from other tasks. Therefore, it may be useful to take into account both temporal and biomechanical measures when considering warning systems to detect texting distraction.
Simuntis, Regimantas; Kubilius, Ričardas; Vaitkus, Saulius
Maxillary sinusitis of odontogenic origin is a well-known condition in both the dental and otolaryngology communities. It occurs when the Schneiderian membrane is violated by conditions arising from dentoalveolar unit. This type of sinusitis differs in its pathophysiology, microbiology, diagnostics and management from sinusitis of other causes, therefore, failure to accurately identify a dental cause in these patients usually lead to persistent symptomatology and failure of medical and surgical therapies directed toward sinusitis. Unilateral recalcitrant disease associated with foul smelling drainage is a most common feature of odontogenic sinusitis. Also, high-resolution CT scans and cone-beam volumetric computed tomography can assist in identifying dental disease. Sometimes dental treatment alone is adequate to resolve the odontogenic sinusitis and sometimes concomitant or subsequent functional endoscopic sinus surgery or Caldwell-Luc operation is required. The aim of this article is to give a review of the most common causes, symptoms, diagnostic and treatment methods of odontogenic maxillary sinusitis. Search on Cochrane Library, PubMed and Science Direct data bases by key words resulted in 35 articles which met our criteria. It can be concluded that the incidence of odontogenic sinusitis is likely underreported in the available literature.
Pope, Caitlin Northcutt; Bell, Tyler Reed; Stavrinos, Despina
Performing secondary tasks, such as texting while driving, is associated with an increased risk of motor vehicle collisions (MVCs). While cognitive processes, such as executive function, are involved in driving, little is known about the relationship between executive control and willingness to engage in distracted driving. This study investigated the relationship between age, behavioral manifestations of executive function, and self-reported distracted driving behaviors. Executive difficulty (assessed with the BRIEF-A) as well as demographics (age and gender) was considered as possible predictors of engagement in distracted driving behaviors. Fifty-nine young, middle, and older adults self-reported executive difficulty and weekly engagement in distracted driving behaviors. Results revealed that while partially accounted for by age, global executive difficulty was uniquely related to engagement in distracted driving behaviors. Older age was associated with fewer weekly self-reported distracted driving behaviors while higher self-reported executive difficulty was associated with more frequent weekly engagement in distracted behavior. No significant differences were found between young and middle-aged adults on distracted driving behaviors. Findings conclude that distracted driving is a ubiquitous phenomenon evident in drivers of all ages. Possible mechanisms underlying distracted driving behavior could potentially be related to deficits in executive function.
Young, Kristie L; Salmon, Paul M
Distracted driving is acknowledged universally as a large and growing road safety problem. Compounding the problem is that distracted driving is a complex, multifaceted issue influenced by a multitude of factors, organisations and individuals. As such, management of the problem is not straightforward. Numerous countermeasures have been developed and implemented across the globe. The vast majority of these measures have derived from the traditional reductionist, driver-centric approach to distraction and have failed to fully reflect the complex mix of actors and components that give rise to drivers becoming distracted. An alternative approach that is gaining momentum in road safety is the systems approach, which considers all components of the system and their interactions as an integrated whole. In this paper, we review the current knowledge base on driver distraction and argue that the systems approach is not currently being realised in practice. Adopting a more holistic, systems approach to distracted driving will not only improve existing knowledge and interventions from the traditional approach, but will enhance our understanding and management of distraction by considering the complex relationships and interactions of the multiple actors and the myriad sources, enablers and interventions that make up the distracted driving system. It is only by recognising and understanding how all of the system components work together to enable distraction to occur, that we can start to work on solutions to help mitigate the occurrence and consequences of distracted driving.
Peacock, Zachary S.; Tricomi, Brad; Murphy, Brian; Magill, John; Kaban, Leonard B.; Troulis, Maria
Purpose To determine if automated continuous distraction osteogenesis at rates > 1mm/day would result in clinical and radiographic bone formation in a minipig model. Materials and Methods An automated, continuous, curvilinear distraction device was placed across a mandibular osteotomy in 10 minipigs. After 12 mm of distraction and 24 days fixation, animals were sacrificed and bone healing evaluated. The continuous distraction rates were 1.5 (n=5) and 3 mm/day (n=5). A semiquantitative scale was used to assess ex-vivo clinical appearance of the distraction gap (3= osteotomy not visible; 2= <50%; 1= >50%; 0= 100% visible); stability (3 = no mobility; 2 and 1 = mobility in 2 or 1 plane respectively; 0= mobility in 3 planes); radiographic density (4 = 100% gap opaque, 3= >75%, 2 = 50% – 75%, 1= <50%, or 0 = radiolucent). Groups of 4 minipigs distracted discontinuously at 1, 2, and 4 mm/day served as controls. Results The continuous DO 1.5 mm/day group had significantly higher scores for appearance and radiographic density compared to the discontinuous 4 mm/day group. The continuous DO 3mm/day group had significantly higher scores for appearance and radiographic density compared to the discontinuous 4 mm/day group, and higher stability compared to the discontinuous 2 and 4 mm/day groups. Conclusions Results of this preliminary study indicate that continuous DO at rates of 1.5 and 3.0 mm/day produces better bone formation when compared to discontinuous DO at rates faster than 1mm/day. PMID:23499159
Blynskiy, F. Yu
The method for automated bone shape correction within bone distraction procedure is presented. High precision deformation angle measurement is provided by the software for X- Ray images processing. Special BDC v.1.0.1. application is designed. The purpose of the BDC is modeling of the bone geometry structure to calculate the appropriate distraction forces. The correction procedure control is realized by the hardware of the distraction system.
... laws and enforcement, changing attitudes and behaviors through education and outreach, and technology...: Distracted Driving Laws and Enforcement Panel 3: Attentive Driving: Changing Attitudes and Behaviors Panel...
Rakauskas, Michael E; Ward, Nicholas J; Boer, Erwin R; Bernat, Edward M; Cadwallader, Meredith; Patrick, Christopher J
Although alcohol and distraction are often cited as significant risk factors for traffic crashes, most research has considered them in isolation. It is therefore necessary to consider the interactions between alcohol and distraction impairment sources, especially when examining the relationship between behavior and crash risk. In a driving simulator, the primary goal was to maintain a safe headway to a lead vehicle and the secondary goal was to maintain stable lane position. All participants engaged in distractions that represented different levels of resource competition and half of the participants consumed alcohol (target BAC 0.08 g/dl). Specific comparisons were made between sober driving while distracted and driving intoxicated without distraction. Distraction tasks produced more changes in driving behavior than did alcohol for both longitudinal (primary) and lateral (secondary) driving goals. Alcohol impairment was evident only in relation to lateral driving performance, however there was an amplification of impairment when alcohol and distraction conditions were combined. Distraction resulted in a general level of impairment across all driving goals, whereas participants with alcohol appeared to shed secondary driving goals to "protect" primary driving goals. Drivers' strategies to cope with alcohol (and distraction) may not be sufficient to offset the increased crash risk.
Wais, Peter E; Gazzaley, Adam
The detrimental influence of distraction on memory and attention is well established, yet it is not as clear whether irrelevant information impacts categorization abilities and whether this impact changes in aging. We examined categorization with morphed prototype stimuli in both younger and older adults, using an adaptive staircase approach to assess participants' performance in conditions with and without visual distractors. Results showed that distraction did not affect younger adults, but produced a negative impact on older adults' categorization such that there was an interaction of age and distraction. These results suggest a relationship between the increased susceptibility to visual distraction in normal aging and impairment in categorization.
Sawant, Ajit S.; Kumar, Vikash; Pawar, Prakash; Tamhankar, Ashwin S.
The bladder neck distraction is a rare posterior urethral injury in paediatric age group. It mostly occurs secondary to road traffic accidents. We report three cases of paediatric bladder neck distraction injury. Three paediatric patients aged between 4 to 7 years (mean 5 year), who presented with post traumatic bladder neck distraction injury but no other major injury, they were treated with early urethro-vesical anastomosis. Postoperatively all patients were continent and with good urine flow rates. In paediatric bladder neck distraction injury, immediate urethro-vesical anastomosis gives good results. PMID:28384935
Conture, Edward G.; Walden, Tedra A.; Lambert, Warren E.
Purpose This study investigated the relation among speech-language dissociations, attentional distractibility, and childhood stuttering. Method Participants were 82 preschool-age children who stutter (CWS) and 120 who do not stutter (CWNS). Correlation-based statistics (Bates, Appelbaum, Salcedo, Saygin, & Pizzamiglio, 2003) identified dissociations across 5 norm-based speech-language subtests. The Behavioral Style Questionnaire Distractibility subscale measured attentional distractibility. Analyses addressed (a) between-groups differences in the number of children exhibiting speech-language dissociations; (b) between-groups distractibility differences; (c) the relation between distractibility and speech-language dissociations; and (d) whether interactions between distractibility and dissociations predicted the frequency of total, stuttered, and nonstuttered disfluencies. Results More preschool-age CWS exhibited speech-language dissociations compared with CWNS, and more boys exhibited dissociations compared with girls. In addition, male CWS were less distractible than female CWS and female CWNS. For CWS, but not CWNS, less distractibility (i.e., greater attention) was associated with more speech-language dissociations. Last, interactions between distractibility and dissociations did not predict speech disfluencies in CWS or CWNS. Conclusions The present findings suggest that for preschool-age CWS, attentional processes are associated with speech-language dissociations. Future investigations are warranted to better understand the directionality of effect of this association (e.g., inefficient attentional processes → speech-language dissociations vs. inefficient attentional processes ← speech-language dissociations). PMID:26126203
Natu, Subodh Shankar; Ali, Iqbal; Alam, Sarwar; Giri, Kolli Yada; Agarwal, Anshita; Kulkarni, Vrishali Ajit
Limb lengthening by distraction osteogenesis was first described in 1905. The technique did not gain wide acceptance until Gavril Ilizarov identified the physiologic and mechanical factors governing successful regeneration of bone formation. Distraction osteogenesis is a new variation of more traditional orthognathic surgical procedure for the correction of dentofacial deformities. It is most commonly used for the correction of more severe deformities and syndromes of both the maxilla and the mandible and can also be used in children at ages previously untreatable. The basic technique includes surgical fracture of deformed bone, insertion of device, 5-7 days rest, and gradual separation of bony segments by subsequent activation at the rate of 1 mm per day, followed by an 8-12 weeks consolidation phase. This allows surgeons, the lengthening and reshaping of deformed bone. The aim of this paper is to review the principle, technical considerations, applications and limitations of distraction osteogenesis. The application of osteodistraction offers novel solutions for surgical-orthodontic management of developmental anomalies of the craniofacial skeleton as bone may be molded into different shapes along with the soft tissue component gradually thereby resulting in less relapse. PMID:24688555
Natu, Subodh Shankar; Ali, Iqbal; Alam, Sarwar; Giri, Kolli Yada; Agarwal, Anshita; Kulkarni, Vrishali Ajit
Limb lengthening by distraction osteogenesis was first described in 1905. The technique did not gain wide acceptance until Gavril Ilizarov identified the physiologic and mechanical factors governing successful regeneration of bone formation. Distraction osteogenesis is a new variation of more traditional orthognathic surgical procedure for the correction of dentofacial deformities. It is most commonly used for the correction of more severe deformities and syndromes of both the maxilla and the mandible and can also be used in children at ages previously untreatable. The basic technique includes surgical fracture of deformed bone, insertion of device, 5-7 days rest, and gradual separation of bony segments by subsequent activation at the rate of 1 mm per day, followed by an 8-12 weeks consolidation phase. This allows surgeons, the lengthening and reshaping of deformed bone. The aim of this paper is to review the principle, technical considerations, applications and limitations of distraction osteogenesis. The application of osteodistraction offers novel solutions for surgical-orthodontic management of developmental anomalies of the craniofacial skeleton as bone may be molded into different shapes along with the soft tissue component gradually thereby resulting in less relapse.
Eighteen patients (20 bony segments) who had shortening and/or angular deformities were treated by distraction osteogenesis using AO-tubular external fixator. The mean angular correction was 18.9 degrees (range, 8-40 degrees). Of the group in whom shortening and angulation was corrected, the mean length gained was 4.2 cm (3-6 cm). The mean treatment time was 4.9 months (range, 2-13 months) and the mean follow-up was 12 months after removal of the fixator (range, 3-30 months). Delayed union with loosening of the fixator occurred in one patient which resulted in residual shortening of 1.5 cm. The author's technique of distraction osteogenesis using AO-tubular fixator with the new distraction rate of 1 mm/48 h (1 mm/step) could adequately correct shortening and/or angular deformities. No extra equipment was needed other than the readily-available AO-tubular fixation systems. No serious complications such as neurovascular injury were encountered.
Lau, Darryl; Shin, Samuel S; Patel, Rakesh; Park, Paul
Cervical fractures can result in severe neurological compromise and even death. One of the most commonly injured segments is the C2 vertebrae, which most frequently involves the odontoid process. In this report, we present the unusual case of a 28-year-old female who sustained a C2 vertebral body fracture (comminuted transverse fracture through the body and both transverse processes) that had both a significant distractive and rotational component, causing the fracture to be highly unstable. Application of halo bracing was unsuccessful. The patient subsequently required a C1-C4 posterior spinal fusion. Follow-up computer tomography imaging confirmed fusion and the patient did well clinically thereafter.
Trento, Guilherme dos Santos; Bernabé, Felipe Bueno Rosettti; da Costa, Delson João; Rebellato, Nelson Luis Barbosa; Klüppel, Leandro Eduardo; Scariot, Rafaela
Abstract Introduction: Patients with dentofacial deformities may undergo orthodontic or orthodontic-surgical treatment. Both modalities can affect esthetics. Objective: This study aims to evaluate clinical and radiographic changes in exposure of maxillary central incisors occurring after orthognathic surgery for maxillary advancement. Methods: A total of 17 patients who underwent orthognathic surgery for maxillary advancement between September, 2010 and July, 2011 were selected. Exposure of maxillary central incisors was evaluated clinically and by lateral cephalograms. Measurements were taken one week before and three months after surgery. Data were paired in terms of sex, age, nasolabial angle, height and thickness of the upper lip, the amount of maxillary advancement, clinical exposure and inclination of maxillary central incisor by statistical tests (CI 95%). Results: After maxillary advancement, incisor clinical exposure had increased even with relaxed lips and under forced smile. Moreover, there was a mean increase of 23.33% revealed by lateral cephalograms. There was an inverse correlation between upper lip thickness and incisors postsurgical exposure revealed by radiographic images (p = 0.002). Conclusions: Significant changes in the exposure of maxillary central incisors occur after maxillary advancement, under the influence of some factors, especially lip thickness. PMID:26691970
Jain, Mahesh; Mogra, Subraya; Chalasani, Srikrishna; D’mello, Kuldeep; Dhakar, Nidhi
A 14-year-old girl reported with severely proclined maxillary anterior teeth with fractured and discolored right maxillary central incisor with questionable prognosis. Autotransplantation of premolar to replace central incisor was considered a risky option as patient was 14-year-old with presence of advanced root development of premolar. The immediate placement of the prosthetic implant was also not possible because of patient's age. Therefore, it was decided to use the space obtained by extracting questionable maxillary right central incisor for orthodontic purpose and also sacrificing the healthy premolar is invariably an excessive biological cost for a modest functional and aesthetic gain. Hence, the treatment plan for this case includes extraction of right maxillary central incisor and left maxillary first premolar, movement of right maxillary lateral incisor mesially, achieving normal axial inclination of maxillary anteriors with normal overjet and overbite. Mandibular arch was treated nonextraction due to congenitally missing central incisors with presence of normally inclined lower anteriors thereby maintaining Angles class I occlusion. Tipping, usually, seen in Begg mechanotherapy was used for our advantage to correct severely proclined maxillary anteriors with simultaneous bite opening mechanics. Case was completed in 19 months and posttreatment records including photographs, radiographs and study models were made. Begg wrap around the retainer was placed in the maxillary arch allowing natural settling of occlusion. PMID:25395777
Khushaba, Rami N; Kodagoda, Sarath; Liu, Diaki; Dissanayake, Gamini
Driver distraction is regarded as a significant contributor to motor-vehicle crashes. One of the important factors contributing to driver distraction was reported to be the handling and reaching of in-car electronic equipment and controls that usually requires taking the drivers' hands off the wheel and eyes off the road. To minimize the amount of such distraction, we present a new control scheme that senses and decodes the human muscles signals, denoted as Electromyogram (EMG), associated with different fingers postures/pressures, and map that to different commands to control external equipment, without taking hands off the wheel. To facilitate such a scheme, the most significant step is the extraction of a set of highly discriminative feature set that can well separate between the different EMG-based actions and to do so in a computationally efficient manner. In this paper, an accurate and efficient method based on Fuzzy Neighborhood Discriminant Analysis (FNDA), is proposed for discriminant feature extraction and then extended to the channel selection problem. Unlike existing methods, the objective of the proposed FNDA is to preserve the local geometrical and discriminant structures, while taking into account the contribution of the samples to the different classes. The method also aims to efficiently overcome the singularity problems of classical LDA by employing the QR-decomposition. Practical real-time experiments with eight EMG sensors attached on the human forearm of eight subjects indicated that up to fourteen classes of fingers postures/pressures can be classified with <7% error on average, proving the significance of the proposed method.
Booij, J. W.; Livas, Christos
The asymmetrical intra-arch relationship in Class II subdivision malocclusion poses challenges in the treatment planning and mechanotherapy of such cases. This case report demonstrates a treatment technique engaging unilateral extraction of a maxillary first molar and Begg fixed appliances. The outcome stability and the enhancing effect on the eruption of the third molar in the extraction segment were confirmed by a 4-year follow-up examination. PMID:27200194
Sung, Eui-Hyang; Kim, Sung-Jin; Chun, Youn-Sic; Park, Young-Chel; Yu, Hyung-Seog
Objective The purpose of this study was to observe stress distribution and displacement patterns of the entire maxillary arch with regard to distalizing force vectors applied from interdental miniscrews. Methods A standard three-dimensional finite element model was constructed to simulate the maxillary teeth, periodontal ligament, and alveolar process. The displacement of each tooth was calculated on x, y, and z axes, and the von Mises stress distribution was visualized using color-coded scales. Results A single distalizing force at the archwire level induced lingual inclination of the anterior segment, and slight intrusive distal tipping of the posterior segment. In contrast, force at the high level of the retraction hook resulted in lingual root movement of the anterior segment, and extrusive distal translation of the posterior segment. As the force application point was located posteriorly along the archwire, the likelihood of extrusive lingual inclination of the anterior segment increased, and the vertical component of the force led to intrusion and buccal tipping of the posterior segment. Rotation of the occlusal plane was dependent on the relationship between the line of force and the possible center of resistance of the entire arch. Conclusions Displacement of the entire arch may be dictated by a direct relationship between the center of resistance of the whole arch and the line of action generated between the miniscrews and force application points at the archwire, which makes the total arch movement highly predictable. PMID:25667914
LaPointe, Leonard L.; Heald, Gary R.; Stierwalt, Julie A. G.; Kemker, Brett E.; Maurice, Trisha
Objective: The effects of interference, competition, and distraction on cognitive processing are unclearly understood, particularly regarding type and intensity of auditory distraction across a variety of cognitive processing tasks. Method: The purpose of this investigation was to report two experiments that sought to explore the effects of types…
Rao, Santhosh; Rao, Sruthi
Orthognathic surgery and alloplastic grafting are the main stay in management in hemifacial microsomia. Distraction osteogenesis is used to increase the ramus and corpus length in the management, but here we have described a technique to increase the height of the body of the mandible using the principles of basal osteotomy and distraction osteogenesis.
Smucny, Jason; Rojas, Donald C.; Eichman, Lindsay C.; Tregellas, Jason R.
Selective attention in the presence of distraction is a key aspect of healthy cognition. The underlying neurobiological processes, have not, however, been functionally well characterized. In the present study, we used functional magnetic resonance imaging to determine how ecologically relevant distracting noise affects cortical activity in 27…
Parks-Stamm, Elizabeth J.; Gollwitzer, Peter M.; Oettingen, Gabriele
College students whose test anxiety was measured completed a working memory-intensive math exam with televised distractions. Students were provided with implementation intentions (if-then plans; Gollwitzer, 1999) designed to either help them ignore the distractions (i.e., temptation-inhibiting plans) or focus more intently on the math exam (i.e.,…
Smektala, Tomasz; Nysjö, Johan; Thor, Andreas; Homik, Aleksandra; Sporniak-Tutak, Katarzyna; Safranow, Krzysztof; Dowgierd, Krzysztof; Olszewski, Raphael
The aim of our study was to evaluate orbital volume modification with LeFort III midface distraction in patients with craniosynostosis and its influence on eyeball volume and axial diameter modification. Orbital volume was assessed by the semiautomatic segmentation method based on deformable surface models and on 3-dimensional (3D) interaction with haptics. The eyeball volumes and diameters were automatically calculated after manual segmentation of computed tomographic scans with 3D slicer software. The mean, minimal, and maximal differences as well as the standard deviation and intraclass correlation coefficient (ICC) for intraobserver and interobserver measurements reliability were calculated. The Wilcoxon signed rank test was used to compare measured values before and after surgery. P < 0.05 was considered statistically significant. Intraobserver and interobserver ICC for haptic-aided semiautomatic orbital volume measurements were 0.98 and 0.99, respectively. The intraobserver and interobserver ICC values for manual segmentation of the eyeball volume were 0.87 and 0.86, respectively. The orbital volume increased significantly after surgery: 30.32% (mean, 5.96 mL) for the left orbit and 31.04% (mean, 6.31 mL) for the right orbit. The mean increase in eyeball volume was 12.3%. The mean increases in the eyeball axial dimensions were 7.3%, 9.3%, and 4.4% for the X-, Y-, and Z-axes, respectively. The Wilcoxon signed rank test showed that preoperative and postoperative eyeball volumes, as well as the diameters along the X- and Y-axes, were statistically significant. Midface distraction in patients with syndromic craniostenosis results in a significant increase (P < 0.05) in the orbit and eyeball volumes. The 2 methods (haptic-aided semiautomatic segmentation and manual 3D slicer segmentation) are reproducible techniques for orbit and eyeball volume measurements.
Marchac, D; Arnaud, E
The wall separating the face and the cranium was broken by Paul Tessier and Gérard Guiot in the 1960s, making it possible to perform a combined operation around the orbits and forehead, and opening up close cooperation between plastic surgeons and neurosurgeons, especially for treatment of the major malformations such as hypertelorism of major facial retrusions. The principles of mobilization of the orbits to correct teleorbitism or orbital dystopia are recalled with reference to the different variations and with clinical examples. Facial advancement to correct the retrusions created by faciocraniosynostosis is explained with the many possible variants, combined with a intracranial approach or not, with or without a bipartition. The indications are discussed as is the risk linked to combined advancement of face and forehead. The progressive bone elongation principle introduced by Ilizarov for the limbs has been applied to the face at the mandibular level by McCarthy, with great success. The distraction of bone structures is now also applied at the level of the midface and makes it possible to overcome the retraction of soft tissues and lower the risk of relapse of facial retrusion. Many technical problems have still to be solved, but the results are already very promising. Many other applications of the distraction principle will be developed for the midface level, with other technical improvements such as the use of absorbable mini-plates and screws.
PURICELLI, Edela; MORGANTI, Mário Alexandre; de AZAMBUJA, Henrique Voltollini; PONZONI, Deise; FRIEDRISCH, Clarice C.
The maxillary canines are amongst the most frequently impacted teeth, second only to the third molars. Several conservative orthodontic and surgical techniques are available to position the teeth properly in the dental arch, even in severe cases. However, when an extraction is necessary, it often leaves a critical alveolar defect of difficult management. The authors present the technique of Partial Maxillary Osteotomy, in which a dento-alveolar segment is moved mesially, hence closing the remaining space, allowing for the formation of healthy periodontium and resulting in an adequate functional and aesthetic outcome. A case report is presented with a 10 year follow-up, proving the technique's stability in the long term. PMID:23329250
Parmentier, Fabrice B. R.; Elsley, Jane V.; Ljungberg, Jessica K.
Unexpected events often distract us. In the laboratory, novel auditory stimuli have been shown to capture attention away from a focal visual task and yield specific electrophysiological responses as well as a behavioral cost to performance. Distraction is thought to follow ineluctably from the sound's low probability of occurrence or, put more…
XUE, Junjie; YE, Niansong; YANG, Xin; WANG, Sheng; WANG, Jing; WANG, Yan; LI, Jingyu; MI, Congbo; LAI, Wenli
Objective The aims of this study were to compare different surgical approaches to rapid canine retraction by designing and selecting the most effective method of reducing resistance by a three-dimensional finite element analysis. Material and Methods Three-dimensional finite element models of different approaches to rapid canine retraction by reducing resistance and distraction were established, including maxillary teeth, periodontal ligament, and alveolar. The models were designed to dissect the periodontal ligament, root, and alveolar separately. A 1.5 N force vector was loaded bilaterally to the center of the crown between first molar and canine, to retract the canine distally. The value of total deformation was used to assess the initial displacement of the canine and molar at the beginning of force loading. Stress intensity and force distribution were analyzed and evaluated by Ansys 13.0 through comparison of equivalent (von Mises) stress and maximum shear stress. Results The maximum value of total deformation with the three kinds of models occurred in the distal part of the canine crown and gradually reduced from the crown to the apex of the canine; compared with the canines in model 3 and model 1, the canine in model 2 had the maximum value of displacement, up to 1.9812 mm. The lowest equivalent (von Mises) stress and the lowest maximum shear stress were concentrated mainly on the distal side of the canine root in model 2. The distribution of equivalent (von Mises) stress and maximum shear stress on the PDL of the canine in the three models was highly concentrated on the distal edge of the canine cervix. Conclusions Removal of the bone in the pathway of canine retraction results in low stress intensity for canine movement. Periodontal distraction aided by surgical undermining of the interseptal bone would reduce resistance and effectively accelerate the speed of canine retraction. PMID:24626249
Liou, Eric Jein-Wein; Chen, Philip K T; Huang, C Shing; Chen, Y Ray
Surgical repositioning of the downward displaced premaxilla in bilateral cleft lip and palate patients remains a controversial and perplexing issue because of its detrimental effects on the growth of the premaxilla. The purpose of this prospective clinical study was to introduce and evaluate the treatment results of an innovative technique for nonsurgically intruding the downward displaced premaxilla. Eight consecutive cases of bilateral cleft lip and palate at the age of mixed dentition were included for the correction of their premaxillary deformities. A pair of intraoral tooth-borne distraction devices was used for the orthopedic intrusion. Serial lateral and posteroanterior cephalometric radiographs were taken periodically for evaluating the growth of the premaxilla 1 year before the intrusion, changes during the intrusion, and growth/relapse up to 1 year after the intrusion. There was no overgrowth of the premaxilla or overeruption of the maxillary incisors during the 1-year observing period before the orthopedic intrusion. The treatment results revealed that the downward displaced premaxillae were all corrected within 1 month. Cephalometrically, 46 percent of the correction resulted from a true orthopedic intrusion and another 54 percent from a dentoalveolar effect in which the maxillary incisors were intruded and the premaxillary dentoalveolus was shortened. The cephalometric evaluations also implied that what occurred during the orthopedic intrusion was mostly the sutural contraction osteogenesis/osteolysis in the vomeropremaxillary suture combined with slightly mechanical upward displacement of the vomeronasal septum complex and nasal bones. The orthopedic intrusion of the premaxilla with distraction devices is an effective nonsurgical method for correcting the downward displaced premaxilla before alveolar bone grafting in patients with bilateral cleft lip and palate, and the results remained stable after 1 year.
Donneys, Alexis; Deshpande, Sagar S.; Tchanque-Fossuo, Catherine N.; Johnson, Kelsey L.; Blough, Jordan T.; Perosky, Joseph E.; Kozloff, Kenneth M.; Felice, Peter A.; Nelson, Noah S.; Farberg, Aaron S.; Levi, Benjamin; Buchman, Steven R.
Background A limitation of mandibular Distraction Osteogenesis (DO) is the length of time required for consolidation. This drawback subjects patients to possible pin-site infections, as well as a prolonged return to activities of normal daily living. Developing innovative techniques to abridge consolidation periods could be immensely effective in preventing these problematic morbidities. Deferoxamine (DFO) is an angiogenic activator that triggers the HIF-1α pathway through localized iron depletion. We previously established the effectiveness of DFO in enhancing regenerate vascularity at a full consolidation period (28 days) in a murine mandibular DO model. To investigate whether this augmentation in vascularity would function to accelerate consolidation, we progressively shortened consolidation periods prior to μCT imaging and biomechanical testing (BMT). Materials and Methods Three time points (14d, 21d and 28d) were selected and six groups of Sprague-Dawley rats (n=60) were equally divided into control (C) and experimental (E) groups for each time period. Each group underwent external fixator placement, mandibular osteotomy, and a 5.1mm distraction. During distraction, the experimental groups were treated with DFO injections into the regenerate gap. After consolidation, mandibles were imaged and tension tested to failure. ANOVA was conducted between groups, and p < 0.05 was considered statistically significant. Results At 14 days of consolidation the experimental group demonstrated significant increases in Bone Volume Fraction (BVF), Bone Mineral Density (BMD) and Ultimate Load (UL) in comparison to non-treated controls. The benefit of treatment was further substantiated by a striking 100% increase in the number of bony unions at this early time-period (C:4/10 vs. E:8/10). Furthermore, metrics of BVF, BMD, Yield and UL at 14 days with treatment demonstrated comparable metrics to those of the fully consolidated 28d control group. Conclusion Based on these
Storms, Ann-Sophie; Voet, Martine; Fieuws, Steffen; Willems, Guy
Objectives: The aim of this study was to establish prediction criteria for maxillary canine impaction in young patients, based on angular and linear measurements on panoramic radiographs. Methods: From 828 records having at least 2 panoramic radiographs, both taken between the ages of 7 and 14 years, with a minimum 1-year and maximum 3-year interval (T1 and T2), a training data set consisting of 30 subjects with unilateral canine impaction (12 males and 18 females) was selected. The patients' mean age was 10.1 years [standard deviation (SD) 1.3 years] at T1 and 11.9 years (SD 1.1 years) at T2. The training data set also consisted of 30 maxillary canines from the contralateral sides and an additional 60 normal erupted canines from 30 subjects. Those 30 subjects of a test data set were selected based on displaying bilateral maxillary canine eruption at T2 and being matched for gender and age with the subjects of the training data set [12 males and 18 females; mean age at T1, 10.1 years (SD 1.3 years) and at T2, 11.1 years (SD 1.2 years)]. Angular and linear measurements were performed separately by two observers on the total study sample at T1. Linear measurements were expressed as a multiplication of the maxillary central incisor width at the non-impacted side. Results: Significant differences for linear and angular measurements and radiographic factors were found between the maxillary impacted canine and erupted maxillary canine. The three best-discriminating parameters were canine to first premolar angle, canine cusp to midline distance and canine cusp to maxillary plane distance. These three parameters were combined in a multiple logistic regression model to calculate the probability of impaction, yielding a high area under the curve (AUC) equal to 0.97 (95% confidence interval: 0.94–0.99), with 90% sensitivity and 94% specificity. Conclusions: Prediction of maxillary canine impaction from a combination of parameters relating to angles and distances measured
Wang, Xuemei; Zhu, Songsong; Jiang, Xiaowen; Li, Yunfeng; Song, Donghui; Hu, Jing
Lithium, popular in psychology field, has been recognized as an activator component of the canonical Wnt signaling pathway. The effect of lithium on osteogenesis or on the human fracture risk has been widely reported. However, little is known on its role in distraction osteogenesis to date. In this study, the effect of systematic administrated lithium on distraction osteogenesis in a rat model was investigated. The osteotomy was performed on the right tibia in 40 adult male Sprague-Dawley rats. Then they were randomly assigned into two equal groups (n = 20/group), which underwent Lithium or saline treatment through gastric gavage until the day they were killed. One week after the osteotomy, the tibias were distracted for 14 days (rate 0.6 mm/day). Following 8 weeks consolidation period, the distracted tibias in both groups were harvested and examined by X-ray plain radiography, histology, dual-energy X-ray absorptiometry, Micro-CT, and biomechanical tests. The results showed that lithium group possessed higher bone mineral density, more mature new bone tissue, and better regenerated bone mass continuity in the distraction gaps without any local or systemic adverse effects was encountered. This study suggested lithium could increase bony callus ossification volume and accelerate distracted tissue mineralization to facilitate bone regeneration in distraction gap.
Stutts, Jane; Feaganes, John; Rodgman, Eric; Hamlett, Charles; Reinfurt, Donald; Gish, Kenneth; Mercadante, Michael; Staplin, Loren
To document drivers’ exposure to potential distractions and the effects of these distractions on driving performance, inconspicuous video camera units were mounted in the vehicles of 70 volunteer subjects. The camera units automatically recorded a closeup view of the driver’s face, a broader view of the interior of the vehicle, and the roadway immediately ahead of the vehicle whenever it was powered on. Three hours of randomly selected data per subject were coded based on a taxonomy of driver distractions (talking on cell phone, eating, tuning radio, etc.), contextual variables (whether vehicle stopped or moving, road type, traffic level, etc.) and observable measures of driver performance (eyes directed inside or outside vehicle, hands on or off steering wheel, and vehicle position in travel lane). Results were analyzed descriptively and using nonparametric bootstrap analysis techniques. The most common distractions in terms of overall event durations were eating and drinking (including preparations to eat or drink), distractions inside the vehicle (reaching or looking for an object, manipulating vehicle controls, etc.), and distractions outside the vehicle (often unidentified). Although many of the distractions were also associated with negative driving performance outcomes, further research is needed to clarify their impact on driving safety. PMID:12941228
Kanno, Takahiro; Mitsugi, Masaharu; Paeng, Jun-Young; Sukegawa, Shintaro; Furuki, Yoshihiko; Ohwada, Hiroyuki; Nariai, Yoshiki; Ishibashi, Hiroaki; Katsuyama, Hideaki; Sekine, Joji
We retrospectively reviewed a new preimplantation regenerative augmentation technique for a severely atrophic posterior maxilla using sinus lifting with simultaneous alveolar distraction, together with long-term oral rehabilitation with implants. We also analyzed the regenerated bone histomorphologically. This study included 25 maxillary sinus sites in 17 patients. The technique consisted of alveolar osteotomy combined with simultaneous sinus lifting. After sufficient sinus lifting, a track-type vertical alveolar distractor was placed. Following a latent period, patient self-distraction was started. After the required augmentation was achieved, the distractor was left in place to allow consolidation. The distractor was then removed, and osseointegrated implants (average of 3.2 implants per sinus site, 80 implants) were placed. Bone for histomorphometric analysis was sampled from six patients and compared with samples collected after sinus lifting alone as controls (n = 4). A sufficient alveolus was regenerated, and all patients achieved stable oral rehabilitation. The implant survival rate was 96.3% (77/80) after an average postloading followup of 47.5 months. Good bone regeneration was observed in a morphological study, with no significant difference in the rate of bone formation compared with control samples. This new regenerative technique could be a useful option for a severely atrophic maxilla requiring implant rehabilitation.
Fernández, Alberto; Usamentiaga, Rubén; Carús, Juan Luis; Casado, Rubén
Driver distraction, defined as the diversion of attention away from activities critical for safe driving toward a competing activity, is increasingly recognized as a significant source of injuries and fatalities on the roadway. Additionally, the trend towards increasing the use of in-vehicle information systems is critical because they induce visual, biomechanical and cognitive distraction and may affect driving performance in qualitatively different ways. Non-intrusive methods are strongly preferred for monitoring distraction, and vision-based systems have appeared to be attractive for both drivers and researchers. Biomechanical, visual and cognitive distractions are the most commonly detected types in video-based algorithms. Many distraction detection systems only use a single visual cue and therefore, they may be easily disturbed when occlusion or illumination changes appear. Moreover, the combination of these visual cues is a key and challenging aspect in the development of robust distraction detection systems. These visual cues can be extracted mainly by using face monitoring systems but they should be completed with more visual cues (e.g., hands or body information) or even, distraction detection from specific actions (e.g., phone usage). Additionally, these algorithms should be included in an embedded device or system inside a car. This is not a trivial task and several requirements must be taken into account: reliability, real-time performance, low cost, small size, low power consumption, flexibility and short time-to-market. The key points for the development and implementation of sensors to carry out the detection of distraction will also be reviewed. This paper shows a review of the role of computer vision technology applied to the development of monitoring systems to detect distraction. Some key points considered as both future work and challenges ahead yet to be solved will also be addressed. PMID:27801822
Fernández, Alberto; Usamentiaga, Rubén; Carús, Juan Luis; Casado, Rubén
Driver distraction, defined as the diversion of attention away from activities critical for safe driving toward a competing activity, is increasingly recognized as a significant source of injuries and fatalities on the roadway. Additionally, the trend towards increasing the use of in-vehicle information systems is critical because they induce visual, biomechanical and cognitive distraction and may affect driving performance in qualitatively different ways. Non-intrusive methods are strongly preferred for monitoring distraction, and vision-based systems have appeared to be attractive for both drivers and researchers. Biomechanical, visual and cognitive distractions are the most commonly detected types in video-based algorithms. Many distraction detection systems only use a single visual cue and therefore, they may be easily disturbed when occlusion or illumination changes appear. Moreover, the combination of these visual cues is a key and challenging aspect in the development of robust distraction detection systems. These visual cues can be extracted mainly by using face monitoring systems but they should be completed with more visual cues (e.g., hands or body information) or even, distraction detection from specific actions (e.g., phone usage). Additionally, these algorithms should be included in an embedded device or system inside a car. This is not a trivial task and several requirements must be taken into account: reliability, real-time performance, low cost, small size, low power consumption, flexibility and short time-to-market. The key points for the development and implementation of sensors to carry out the detection of distraction will also be reviewed. This paper shows a review of the role of computer vision technology applied to the development of monitoring systems to detect distraction. Some key points considered as both future work and challenges ahead yet to be solved will also be addressed.
Pal, Jitendra N; Banik, Rajeeb
Introduction: Radial bone loss associated with gross manus valgus deformity can be managed by open reduction internal fixation using intervening strut bone graft, callus distraction using ring or monoaxial fixator, and achieving union by distraction histogenesis. These methods are particularly suitable when bone loss is small. Single or staged procedure is described for congenital as well as in acquired extensive bone loss of radius. Distraction through radial proximal to distal segments, to achieve reduction of distal radio-ulnar joint (DRUJ), is also described in acquired cases. In the present series, functional results of distraction through ulna to 2nd metacarpal is studied alongwith, functional status of hand, stability of wrist, level of patient's satisfaction are also studied. Materials and Methods: 7 unilateral cases of radial loss (M = 5, F = 2) affecting 4 right hands of mean age 17 years (range 9 to 24 years) were included in this study. They were treated by distracting through ulna to 2nd metacarpal to achieve DRUJ alignment in first stage. Subsequently ulna was osteotomised and translated to distal stump of radius. It was then fixed to the distal radial remnant in 30° pronation in dominant and 30° supination non dominant hands. Results: Union was achieved in all cases associated with beneficial cross union of distal ulna. Hand functions improved near to normal, with fully corrected stable wrist joint, hypertrophied ulna and without recurrence. All of them had practically complete loss of forearm rotations, however patients were fully satisfied. Conclusion: This method is particularly suitable when associated with 6 cm or more radial bone loss. But when loss is small, sacrifice of one bone may not be justifiable. PMID:23325973
Purani, Jigar M; Purani, Hiral J
Dens invaginatus is a developmental disturbance of the tooth and usually occurs in the maxillary lateral incisor of permanent dentition. In this article, a rare case of dens invaginatus affecting multiple permanent maxillary teeth is described.
Oliveira, Tiago Maia Fernandes; Claudino, Lígia Vieira; Mattos, Cláudia Trindade; Sant'Anna, Eduardo Franzotti
ABSTRACT Objective: The aim of this preliminary study was to assess changes in tooth length and alveolar thickness following retraction of maxillary incisors. Methods: A total of 11 patients presenting severe maxillary dentoalveolar protrusion revealed by initial (T1) cone-beam computed tomography (CBCT), and whose treatment plan included extraction of maxillary first premolars and retraction of maxillary incisors, were selected and submitted to CBCT examination one month after the end of incisors retraction (T2). The premaxilla was assessed through seven axial slices by means of Dolphin ImagingTM software. In each of these slices, five measurements of the distance from the buccal cortical bone to the palatal cortical bone were performed. Tooth length of maxillary incisors (n = 44) was also measured in sagittal slices. Measurements were repeated after a two-week interval, and intraclass correlation coefficient (ICC) was used to test examiner calibration. Wilcoxon test was used to detect differences in measurements performed at the two time intervals. Results: The ICC was satisfactory for tooth length (0.890) and for premaxilla alveolar thickness measurements (0.980). Analysis of data showed no statistically significant differences (p > 0.05) in tooth length or alveolar thickness between the two-time intervals assessed. Conclusion: The force used in retraction of maxillary incisors in this research did not promote significant changes in tooth length of maxillary incisors or in premaxilla alveolar thickness. PMID:27901233
Nilsson, Stefan; Enskär, Karin; Hallqvist, Carina; Kokinsky, Eva
The aim of this study was to test how distraction influences pain, distress and anxiety in children during wound care. Sixty participants aged 5-12 years were randomized to three groups: serious gaming, the use of lollipops and a control group. Self-reported pain, distress, anxiety and observed pain behaviour were recorded in conjunction with wound care. Serious gaming, an active distraction, reduced the observed pain behaviour and self-reported distress compared with the other groups. A sense of control and engagement in the distraction, together, may be the explanation for the different pain behaviours when children use serious gaming.
Ecevit, Mustafa Cenk; Sarıoğlu, Sülen; Sütay, Semih
Ameloblastic fibroodontoma (AFO) is a rare entity of mixed odontogenic tumors and frequently arises from posterior portion of the maxilla or mandible in first two decades of life. Herein, a 35-year-old woman with a noncontributory medical history who presented with a progressive left maxillary toothache, left maxillary first molar tooth mobility, and swelling in the left maxillary molar area for the last 2 months was reported. Radiologically, a tumor that originated from periapical area of the second mature molar teeth of maxilla was seen and additively unerupted tooth was not detected. The histopathologic examination revealed AFO. The patient is disease-free for five years after treated with limited segmental alveolectomy combining with Caldwell-Luc procedure. PMID:27891277
Park, Sam-Sik; Kim, Bo-Kyung; Moon, Ok-Kon; Choi, Wan-Suk
[Purpose] The study investigated the effects of joint position on the distraction distance during Grade III glenohumeral joint distraction in healthy individuals. [Subjects and Methods] Twenty adults in their forties without shoulder disease were randomly divided into neutral position group (NPG; n = 7), resting position group (RPG; n = 7), and end range position group (ERPG; n = 6). After Kaltenborn Grade III distraction for 40s, the distance between glenoid fossa and humeral head was measured by ultrasound. [Results] The average distances between the humeral head and glenoid fossa before distraction were 2.86 ± 0.81, 3.21 ± 0.47, and 3.55 ± 0.59 mm for the NP, RP, and ERP groups. The distances after applying distraction were 3.12 ± 0.51, 3.86 ± 0.55, and 4.35 ± 0.32 mm. Between-group comparison after applying distraction revealed no significant differences between the NP and RP groups, while there was a statistically significant difference between the NP and RP groups, as well as between the NP and ERP groups. [Conclusion] Joint space was largest in ERP individuals when performing manual distraction. PMID:26644692
Dental infections and maxillary sinusitis are the main causes of osteomyelitis. Osteomyelitis can occur in all age groups, and is more frequently found in the lower jaw than in the upper jaw. Systemic conditions that can alter the patient's resistance to infection including diabetes mellitus, anemia, and autoimmune disorders are predisposing factors for osteomyelitis. We report a case of uncommon broad maxillary osteonecrosis precipitated by uncontrolled type 2 diabetes mellitus and chronic maxillary sinusitis in a female patient in her seventies with no history of bisphosphonate or radiation treatment. PMID:26734561
Sörqvist, Patrik; Rönnberg, Jerker
This paper reviews the current literature on individual differences in susceptibility to the effects of background sound on visual-verbal task performance. A large body of evidence suggests that individual differences in working memory capacity (WMC) underpin individual differences in susceptibility to auditory distraction in most tasks and contexts. Specifically, high WMC is associated with a more steadfast locus of attention (thus overruling the call for attention that background noise may evoke) and a more constrained auditory-sensory gating (i.e., less processing of the background sound). The relation between WMC and distractibility is a general framework that may also explain distractibility differences between populations that differ along variables that covary with WMC (such as age, developmental disorders, and personality traits). A neurocognitive task-engagement/distraction trade-off (TEDTOFF) model that summarizes current knowledge is outlined and directions for future research are proposed. PMID:25632345
Glowacki, Julie; Shusterman, E Mark; Troulis, Maria; Holmes, Ralph; Perrott, David; Kaban, Leonard B
Distraction osteogenesis is a technique for skeletal lengthening that exploits the body's innate capacity for bone formation in response to tension forces on the repair callus. The authors developed a distraction osteogenesis model with a semiburied device in the Yucatan minipig mandible because of similarities between human and porcine mandibular anatomy, temporomandibular function, chewing patterns, and bone turnover rates. The purpose of this study was to measure histomorphometric bone fill after different latency periods, rates of distraction, and duration of neutral fixation in the minipig mandible. In addition, the relationship between histomorphometric bone fill and clinical stability was investigated. Mandibular osteotomies in 20 female Yucatan minipigs weighing 25 to 30 kg were distracted with modified semiburied distraction devices. Variables included 0-day or 4-day latency; 1-mm, 2-mm, or 4-mm daily distraction rates; gap size of 7 or 12 mm; and evaluation after neutral fixation for various lengths of time. Specimens were fixed in 2% paraformaldehyde, pH 7.4, before being embedded in methylmethacrylate. Sections were prepared from the region just below the inferior alveolar canal. The area of new bone formation within the gap was measured and expressed as a percentage of the total area of the distraction gap. Bone fill ranged from 0 to 100 percent. A pilot study with 7-mm advancements showed similar bone fill with 0-day or 4-day latency, but with poor reproducibility. Mandibles that were distracted to 12 mm at 1 mm per day exhibited nearly complete bone fill, either with 0-day latency (average, 93 percent) or 4-day latency (average, 100 percent). Mandibles that had been distracted for 3 days at 4 mm per day showed moderate osteogenesis and clinical stability with increasing time of neutral fixation. Bone fill was significantly correlated with clinical stability (Spearman r = 0.801, p = 0.001). Histological examination showed exuberant periosteal
Kountouriotis, Georgios K; Spyridakos, Panagiotis; Carsten, Oliver M J; Merat, Natasha
The influence of driver distraction on driving performance is not yet well understood, but it can have detrimental effects on road safety. In this study, we examined the effects of visual and non-visual distractions during driving, using a high-fidelity driving simulator. The visual task was presented either at an offset angle on an in-vehicle screen, or on the back of a moving lead vehicle. Similar to results from previous studies in this area, non-visual (cognitive) distraction resulted in improved lane keeping performance and increased gaze concentration towards the centre of the road, compared to baseline driving, and further examination of the steering control metrics indicated an increase in steering wheel reversal rates, steering wheel acceleration, and steering entropy. We show, for the first time, that when the visual task is presented centrally, drivers' lane deviation reduces (similar to non-visual distraction), whilst measures of steering control, overall, indicated more steering activity, compared to baseline. When using a visual task that required the diversion of gaze to an in-vehicle display, but without a manual element, lane keeping performance was similar to baseline driving. Steering wheel reversal rates were found to adequately tease apart the effects of non-visual distraction (increase of 0.5° reversals) and visual distraction with offset gaze direction (increase of 2.5° reversals). These findings are discussed in terms of steering control during different types of in-vehicle distraction, and the possible role of manual interference by distracting secondary tasks.
Saxby, T; Nunley, J A
Two cases of lengthening of metatarsals by distraction osteogenesis are reported. One of these cases is an acquired deformity of the first metatarsal; the other is a congenital short fourth metatarsal. By following the principles set forth by Ilizarov, it was possible to lengthen the metatarsal bones and surrounding soft tissues without open lengthening of tendons or secondary bone grafting of the distraction gap. We believe this method is an improvement over previously described methods of metatarsal lengthening.
Neelakandan, R S; Bhargava, Darpan
Reconstruction of the facial skeleton remains a herculean task for a reconstructive surgeon, even with the availability of ample reconstructive options. Transport distraction osteogenesis is a novel reconstructive modality in the armamentarium of a maxillofacial reconstructive surgeon with obvious advantages of osteogenesis and histogenesis from the residual host tissues after tumor ablative surgeries or trauma and also, precludes donor site morbidity. This paper reviews the current concepts, principles involved and applications of transport distraction osteogenesis in maxillomandibular reconstruction.
Shen, Ying; Gao, Junqi; Wang, Yaojin; Hasanyan, Davresh; Finkel, Peter; Li, Jiefang; Viehland, D.
A magnetic flux distraction effect caused by a nearby metallic material was investigated for Metglas/Pb(Mg1/3Nb2/3)O3-PbTiO3 laminated magnetoelectric (ME) sensors. Using flux distraction, a ME sensor can perform an accurate search for metallic targets of different dimensions at various distances. Detection results and simulations were in good agreement. The findings demonstrate an effective means to employ stationary ME sensors and gradiometers for magnetic search applications.
Hino, Claudia Toyama; Cevidanes, Lucia H. S.; Nguyen, Tung T.; De Clerck, Hugo J.; Franchi, Lorenzo; McNamara, James A.
Introduction Our objectives in this study were to evaluate in 3 dimensions the growth and treatment effects on the midface and the maxillary dentition produced by facemask therapy in association with rapid maxillary expansion (RME/FM) compared with bone-anchored maxillary protraction (BAMP). Methods Forty-six patients with Class III malocclusion were treated with either RME/FM (n = 21) or BAMP (n = 25). Three-dimensional models generated from cone-beam computed tomographic scans, taken before and after approximately 1 year of treatment, were registered on the anterior cranial base and measured using color-coded maps and semitransparent overlays. Results The skeletal changes in the maxilla and the right and left zygomas were on average 2.6 mm in the RME/FM group and 3.7 mm in the BAMP group; these were different statistically. Seven RME/FM patients and 4 BAMP patients had a predominantly vertical displacement of the maxilla. The dental changes at the maxillary incisors were on average 3.2 mm in the RME/FM group and 4.3 mm in the BAMP group. Ten RME/FM patients had greater dental compensations than skeletal changes. Conclusions This 3-dimensional study shows that orthopedic changes can be obtained with both RME/FM and BAMP treatments, with protraction of the maxilla and the zygomas. Approximately half of the RME/FM patients had greater dental than skeletal changes, and a third of the RME/FM compared with 17% of the BAMP patients had a predominantly vertical maxillary displacement. PMID:24182587
Shimi, Andria; Woolrich, Mark W.; Mantini, Dante; Astle, Duncan E.
Our ability to maintain small amounts of information in mind is critical for successful performance on a wide range of tasks. However, it remains unclear exactly how this maintenance is achieved. One possibility is that it is brought about using mechanisms that overlap with those used for attentional control. That is, the same mechanisms that we use to regulate and optimize our sensory processing may be recruited when we maintain information in visual short-term memory (VSTM). We aimed to test this hypothesis by exploring how distracter filtering is modified by concurrent VSTM load. We presented participants with sequences of target items, the order and location of which had to be maintained in VSTM. We also presented distracter items alongside the targets, and these distracters were graded such that they could be either very similar or dissimilar to the targets. We analyzed scalp potentials using a novel multiple regression approach, which enabled us to explore the neural mechanisms by which the participants accommodated these variable distracters on a trial-to-trial basis. Critically, the effect of distracter filtering interacted with VSTM load; the same graded changes in perceptual similarity exerted effects of a different magnitude depending upon how many items participants were already maintaining in VSTM. These data provide compelling evidence that maintaining information in VSTM recruits an overlapping set of attentional control mechanisms that are otherwise used for distracter filtering. PMID:25610387
Agmo, A; Medrano, A; Garrido, N; Alonso, P
Drugs facilitating GABAergic neurotransmission have been reported to block some behavioral actions of dopaminergic stimulation but not others. The present experiments were performed with the purpose to extend the range of behaviors in which the interaction between GABA and dopamine have been studied. The ability of the GABAB agonist baclofen and the GABA transaminase inhibitor sodium valproate to block the enhanced distractibility produced by amphetamine was evaluated in a procedure especially designed for analyzing drugs' effects on distractibility. Briefly, rats were trained to traverse a straight runway with a sucrose solution as reinforcement. Once the response had been acquired, an additional runway ending in an empty box was connected. The time spent investigating this additional runway is the measure of distractibility. Male rats treated with amphetamine, 1 mg/kg, displayed an increase of the time spent in the additional runway. Baclofen, 2.5 and 5 mg/kg, and sodium valproate, 100 and 200 mg/kg, had no effect on distraction behavior when administered alone. However, when these drugs were administered together with amphetamine, 1 mg/kg, they completely inhibited the effects of the stimulant on distractibility. These data show that distractibility is similar to discrimination learning with regard to the capacity of GABAergic drugs to block the effects of dopaminergic stimulation. It is different from locomotor activity, however, where GABAergic drugs are ineffective in this respect.
Thompson, Kelsey R; Johnson, Amy M; Emerson, Jamie L; Dawson, Jeffrey D; Boer, Erwin R; Rizzo, Matthew
Automobile driving is a safety-critical real-world example of multitasking. A variety of roadway and in-vehicle distracter tasks create information processing loads that compete for the neural resources needed to drive safely. Drivers with mind and brain aging may be particularly susceptible to distraction due to waning cognitive resources and control over attention. This study examined distracted driving performance in an instrumented vehicle (IV) in 86 elderly (mean=72.5 years, SD=5.0 years) and 51 middle-aged drivers (mean=53.7 years, SD=9.3 year) under a concurrent auditory-verbal processing load created by the Paced Auditory Serial Addition Task (PASAT). Compared to baseline (no-task) driving performance, distraction was associated with reduced steering control in both groups, with middle-aged drivers showing a greater increase in steering variability. The elderly drove slower and showed decreased speed variability during distraction compared to middle-aged drivers. They also tended to "freeze up", spending significantly more time holding the gas pedal steady, another tactic that may mitigate time pressured integration and control of information, thereby freeing mental resources to maintain situation awareness. While 39% of elderly and 43% of middle-aged drivers committed significantly more driving safety errors during distraction, 28% and 18%, respectively, actually improved, compatible with allocation of attention resources to safety critical tasks under a cognitive load.
Wetzel, Nicole; Schröger, Erich; Widmann, Andreas
The control of attention is an important part of our executive functions and enables us to focus on relevant information and to ignore irrelevant information. The ability to shield against distraction by task-irrelevant sounds is suggested to mature during school age. The present study investigated the developmental time course of distraction in three groups of children aged 7–10 years. Two different types of distractor sounds that have been frequently used in auditory attention research—novel environmental and pitch-deviant sounds—were presented within an oddball paradigm while children performed a visual categorization task. Reaction time measurements revealed decreasing distractor-related impairment with age. Novel environmental sounds impaired performance in the categorization task more than pitch-deviant sounds. The youngest children showed a pronounced decline of novel-related distraction effects throughout the experimental session. Such a significant decline as a result of practice was not observed in the pitch-deviant condition and not in older children. We observed no correlation between cross-modal distraction effects and performance in standardized tests of concentration and visual distraction. Results of the cross-modal distraction paradigm indicate that separate mechanisms underlying the processing of novel environmental and pitch-deviant sounds develop with different time courses and that these mechanisms develop considerably within a few years in middle childhood. PMID:28018281
Abd Jalil, Laila; Muhd Noor, Nurhidayah
The report presents examples of successful cases of autotransplantation of ectopic teeth as donor in the treatment of clinically missing maxillary anterior teeth in young patients. The transplanted teeth were either severely ectopic, inverted, rotated or in an unfavourable position that they are commonly sacrificed as a result. Details of surgical technique as well as clinical and radiographic assessments were discussed. PMID:28352481
Jaija, Abdullah M. Zakria; El-Beialy, Amr Ragab; Mostafa, Yehya A.
Aim. The aim of this study is to analyze the etiological factors underlying the presence of maxillary midline diastema in a sample of orthodontic patients. Materials and Methods. One hundred patients who fulfill the inclusion criteria were selected from 1355 patients seeking orthodontic treatment. The pretreatment orthodontic records were analyzed. The width of the maxillary midline diastema was measured clinically with a digital caliper at two levels: the mesioincisal angles of the central incisors and five millimeters from the incisal edge. The two measurements were averaged, and patients with diastema of more than 0.5 millimeter in width were enrolled. Results. Diastema is a multifactorial clinical finding with more than one underlying etiological cause. The interrelationship between the familial pattern of midline diastema and the microdontia, macroglossia, labial frenum, and alveolar cleft conforms was clear. The effect of a mesiodens and the upper lateral incisor whether bilaterally missing, unerupted, or peg shaped was minimal. Conclusion. Etiological factors underlying maxillary midline diastema are interconnected. Using a checklist as a guide during handling maxillary midline diastema is important in the different stages of treatment. PMID:27239374
Cadenat, H; Barthélémy, R; Izac, F; Clouet, M; Fabert, G
The writers have studied mandibular anomalies in a series of 20 surgically treated clefts. Anomalies of shape occur in one case out of two and are in the form of a mandible which is too long. Anomalies of position most often show a mandible in front of the maxillary and to the rear in comparison to the base of the skull.
Stine, Kimo C.; Wahl, Elizabeth C.; Liu, Lichu; Skinner, Robert A.; Schilden, Jaclyn Vander; Bunn, Robert C.; Montgomery, Corey O.; Suva, Larry J.; Aronson, James; Becton, David L.; Nicholas, Richard W.; Swearingen, Christopher J.; Lumpkin, Charles K.
Osteosarcoma (OS) is the most common malignant bone tumor affecting children and adolescents. Many patients are treated with a combination of chemotherapy, resection, and limb salvage protocols. Surgical reconstructions after tumor resection include structural allografts, non-cemented endoprostheses, and distraction osteogenesis (DO), which require direct bone formation. Although cisplatin (CDP) is extensively used for OS chemotherapy, the effects on bone regeneration are not well studied. The effects of CDP on direct bone formation in DO were compared using two dosing regimens and both C57BL/6 (B6) and tumor necrosis factor receptor 1 knockout (TNFR1KO) mice, as CDP toxicity is associated with elevated TNF levels. Detailed evaluation of the five dose CDP regimen (2mg/kg/day), demonstrated significant decreases in new bone formation in the DO gaps of CDP treated versus vehicle treated mice (P<0.001). Further, no significant inhibitory effects from the 5 dose CDP regimen were observed in TNFR1KO mice. The two dose regimen significantly inhibited new bone formation in B6 mice. These results demonstrate that CDP has profound short term negative effects on the process of bone repair in DO. These data provide the mechanistic basis for modeling peri-operative chemotherapy doses and schedules and may provide new opportunities to identify molecules that spare normal cells from the inhibitory effects of CDP. PMID:24259375
Uribe, Flavio; Cutrera, Alice; Nanda, Ravinda
This case report describes the use of a segmented appliance for space closure prior to using Invisalign. The maxillary right canine was retracted into the extracted first premolar space with a sectional wire from the first molar to the canine with no visible brackets in the incisor region. The advantage of this technique is the ability to achieve better root and rotational control during space closure with a fixed appliance that also has limited visibility. A maxillary fixed appliance was used to refine the esthetics in the maxillary arch due to the limitations of the Invisalign appliance in achieving rotational and vertical movements.
Leyes, M; Noonan, K J; Forriol, F; Cañadell, J
In this study, we documented the prevalence of coronal axis malalignment in a series of 93 tibias (from 54 patients) lengthened with monolateral fixation. The average length obtained by distraction osteogenesis was 8.9 cm (range, 3.5-15.6) or 38% of the original bone length (range, 11-78%). Fifty (54%) of 93 tibias had documented valgus angulation of > or = 10 degrees or had fixator manipulation during the lengthening process for undesirable or progressive angulation; no cases of varus angulation were noted. Thirteen (14%) segments had later corrective osteotomy for unsatisfactory valgus malalignment. Statistical analysis revealed two factors to have a significant effect on the rate of malalignment. Those cases that had tibial osteotomy below the proximal one third of the original tibial length and those cases in which the fixator was placed > 5 degrees out of parallel had higher rates of angulation or manipulation (p < 0.001 and p = 0.002). Although the percentage of original bone lengthened was not statistically significant (p = 0.083), it did have an important effect on rates of axial malalignment. From this study we conclude that relatively high rates of malalignment in the tibia during distraction osteogenesis with monolateral external fixation are predominately the result of more distal osteotomies and nonparallel fixator placement. Attention to these details in general, and particularly where long lengthenings are planned, may significantly reduce this common complication.
Victor, J B; Halverson, C F
The present paper reports on the development of a modified problem checklist for use in normal samples of elementary school children. The two factors, Hypersensitivity and Distractibility, replicated over male and female samples. Hypersensitivity showed a significant grade effect, with a decrease between the first and second grade for both boys and girls. In contrast, boys scored higher than girls on Distractibility and there were no grade differences. Convergent validitiy data from peer judgments, in-class activity level, physical fitness measures, standardized achievement scores, and a comparison with another teacher judgment are presented. In addition, three Behavioral Problem Checklist (Quay & Peterson, 1967) dimensions, Conduct Problem, Personality Problem, and Inadequacy--Immaturity, were developed and their relationships to the independent measures, as well as to the new dimensions, are presented. The pattern of correlations of Distractibility was quite similar for boys and girls, with both being rated as Mean-Noisy by their peers. The findings for Hypersensitivity were somewhat weaker. Distractibility and Conduct Problem scores reflected a similar pattern of correlations with other variables; in a like manner, Hypersensitivity and Personality Problem scores reflected a similar pattern of correlations with other variables. Distractibility was related to an increased activity level and Hypersensitivity was related to a decreased activity level in young boys. The total number of behavior problems was related to a decrease in activity level for young girls. Older Distractible and Hypersensitive girls showed different patterns of activity level. It is proposed that problem behavior is more complex for older children and that Distractibility may be less influenced by the usual socialization process of school than is Hypersensitivity and may have some congenital antecedents.
Stavrinos, Despina; Jones, Jennifer L.; Garner, Annie A.; Griffin, Russell; Franklin, Crystal A.; Ball, David; Welburn, Sharon C.; Ball, Karlene K.; Sisiopiku, Virginia P.; Fine, Philip R.
Studies have documented a link between distracted driving and diminished safety; however, an association between distracted driving and traffic congestion has not been investigated in depth. The present study examined the behavior of teens and young adults operating a driving simulator while engaged in various distractions (i.e., cell phone, texting, and undistracted) and driving conditions (i.e., free flow, stable flow, and oversaturation). Seventy five participants 16 to 25 years of age (split into 2 groups: novice drivers and young adults) drove a STISIM simulator three times, each time with one of three randomly presented distractions. Each drive was designed to represent daytime scenery on a 4 lane divided roadway and included three equal roadway portions representing Levels of Service (LOS) A, C, and E as defined in the 2000 Highway Capacity Manual. Participants also completed questionnaires documenting demographics and driving history. Both safety and traffic flow related driving outcomes were considered. A Repeated Measures Multivariate Analysis of Variance was employed to analyze continuous outcome variables and a Generalized Estimate Equation (GEE) poisson model was used to analyze count variables. Results revealed that, in general more lane deviations and crashes occurred during texting. Distraction (in most cases, text messaging) had a significantly negative impact on traffic flow, such that participants exhibited greater fluctuation in speed, changed lanes significantly fewer times, and took longer to complete the scenario. In turn, more simulated vehicles passed the participant drivers while they were texting or talking on a cell phone than while undistracted. The results indicate that distracted driving, particularly texting, may lead to reduced safety and traffic flow, thus having a negative impact on traffic operations. No significant differences were detected between age groups, suggesting that all drivers, regardless of age, may drive in a manner
Zaffe, Davide; Bertoldi, Carlo; Palumbo, Carla; Consolo, Ugo
Alveolar Distraction Osteogenesis (ADO) is a process which forms new alveolar bone to correct alveolar deformities in ridge height and width. This work aims (a). to verify the predictability of the augmentation of height of atrophic alveolar ridges using an extra-alveolar distraction device and (b). to study the bone processes in order to optimize implanto-prosthetic rehabilitation. ADO was performed on 10 patients with ridge deformities to obtain the required ridge augmentation. Clinical and radiological (OPT and CT with densitometric assay) evaluations were carried out during the following 12 weeks, before implant insertion. Biopsies at 40, 60 and 88 days were studied after general, specific and histochemical staining of slides; microradiographs were analyzed to evaluate the Trabecular Bone Volume. Forty days after the end of distraction, soft callus indicated the start of ossification. Sixty days after the end of distraction, the soft callus was largely converted into a network of trabecular woven bone; osteogenic activity was high and TBV was about 50%. Eighty-eight days after the end of distraction, the amount of bone appeared reduced, with a more ordered structure; bone formation activity and TBV also diminished, whereas osteoclast erosion was active. The densitometric assay shows values increasing from the end of distraction, particularly after implant insertion. Histological results show a regression in bone deposition processes 88 days after the end of distraction culminating in a virtual steady-state after a certain time. The results suggest that early implant insertion may be desirable to avoid bone loss due to mechanical unloading.
Stavrinos, Despina; Jones, Jennifer L; Garner, Annie A; Griffin, Russell; Franklin, Crystal A; Ball, David; Welburn, Sharon C; Ball, Karlene K; Sisiopiku, Virginia P; Fine, Philip R
Studies have documented a link between distracted driving and diminished safety; however, an association between distracted driving and traffic congestion has not been investigated in depth. The present study examined the behavior of teens and young adults operating a driving simulator while engaged in various distractions (i.e., cell phone, texting, and undistracted) and driving conditions (i.e., free flow, stable flow, and oversaturation). Seventy five participants 16-25 years of age (split into 2 groups: novice drivers and young adults) drove a STISIM simulator three times, each time with one of three randomly presented distractions. Each drive was designed to represent daytime scenery on a 4 lane divided roadway and included three equal roadway portions representing Levels of Service (LOS) A, C, and E as defined in the 2000 Highway Capacity Manual. Participants also completed questionnaires documenting demographics and driving history. Both safety and traffic flow related driving outcomes were considered. A Repeated Measures Multivariate Analysis of Variance was employed to analyze continuous outcome variables and a Generalized Estimate Equation (GEE) Poisson model was used to analyze count variables. Results revealed that, in general more lane deviations and crashes occurred during texting. Distraction (in most cases, text messaging) had a significantly negative impact on traffic flow, such that participants exhibited greater fluctuation in speed, changed lanes significantly fewer times, and took longer to complete the scenario. In turn, more simulated vehicles passed the participant drivers while they were texting or talking on a cell phone than while undistracted. The results indicate that distracted driving, particularly texting, may lead to reduced safety and traffic flow, thus having a negative impact on traffic operations. No significant differences were detected between age groups, suggesting that all drivers, regardless of age, may drive in a manner
Mavani, Kinjal J
Introduction The management of highly comminuted distal radius fractures still remains a major treatment challenge. Articular comminution and compromised bone quality are the culprits. One novel approach is the technique of Internal Distraction Plating which involves “bridging” the fracture with the use of a standard 3.5mm plate applied dorsally in distraction from the radius, proximal to the fracture, to the long finger metacarpal distally, bypassing the comminuted segment. The plate is removed once fracture union has been achieved. Aim The present study was conducted with the aim to evaluate the role of internal dorsal distraction plating as an alternative method in the treatment of fracture distal radius in terms of special indications, technique and outcome. Materials and Methods This study was a prospective longitudinal study on 20 patients (mean age 62 years) treated with internal distraction plating for comminuted distal radius fractures with specific indications. Regular follow-ups with standard radiographs and analysis were done upto 24 months. Functional outcome were assessed by DASH Score and the Gartland and Werley demerit score. Results At final follow-up, all fractures had united and X-rays showed mean palmar tilt of 7°, positive ulnar variance of 0.5mm, radial inclination of 18° and average loss of 2mm of radial height. Mean range of motion values for wrist flexion 46°, extension 50°, pronation 79° and supination 77° At final follow-up, the mean DASH score was 32. 85% patient had excellent to good result as per Gartland and Werley demerit score. This construct has yield satisfactory clinical and radiographic results with these very challenging injuries. Conclusion The purpose of this study was to report the radiographic and the functional outcomes of treatment with this technique. External fixator and volar plating in communited distal end radius fractures are not always satisfactory in old age with osteoporotic bone because of
Leventhal, Evan L.; Moore, Douglas C.; Akelman, Edward; Wolfe, Scott W.; Crisco, Joseph J.
Introduction Wrist distraction is a common treatment maneuver used clinically for the reduction of distal radial fractures and mid-carpal dislocations. Wrist distraction is also required during wrist arthroscopy to access the radiocarpal joint and has been used as a test for scapholunate ligament injury. However, the effect of a distraction load on the normal wrist has not been well studied. The purpose of this study was to measure the 3-D conformational changes of the carpal bones in the normal wrist as a result of a static distractive load. Methods The dominant wrists of 14 healthy volunteers were scanned using computed tomography at rest and during application of 98N of distraction. Load was applied using finger traps and volunteers were encouraged to relax their forearm muscles and to allow distraction of the wrist. The motions of the bones in the wrist were tracked between the unloaded and loaded trial using markerless bone registration. The average displacement vector of each bone was calculated relative to the radius as well as the interbone distances for 20 bone-bone interactions. Joint separation was estimated at the radiocarpal, midcarpal and carpal-metacarpal joints in the direction of loading using the radius, lunate, capitate and 3rd metacarpal. Results With loading, the distance between the radius and 3rd metacarpal increased an average of 3.3±3.1mm in the direction of loading. This separation was primarily located in the axial direction at the radiocarpal (1.0±1.0mm) and midcarpal (2.0±1.7mm) joints. There were minimal changes in the transverse direction within the distal row, although the proximal row narrowed by 0.98±0.7mm. Distraction between the radius and scaphoid (2.5±2.2mm) was 2.4 times greater than between the radius and lunate (1.0±1.0mm). Conclusions Carpal distraction has a significant effect on the conformation of the carpus, especially at the radiocarpal and midcarpal joints. In the normal wrist, external traction causes twice as
Morgan, Elise F; Longaker, Michael T; Carter, Dennis R
Mechanical factors modulate the morphogenesis and regeneration of mesenchymally derived tissues via processes mediated by the extracellular matrix (ECM). In distraction osteogenesis, large volumes of new bone are created through discrete applications of tensile displacement across an osteotomy gap. Although many studies have characterized the matrix, cellular and molecular biology of distraction osteogenesis, little is known about relationships between these biological phenomena and the local physical cues generated by distraction. Accordingly, the goal of this study was to characterize the local physical environment created within the osteotomy gap during long bone distraction osteogenesis. Using a computational approach, we quantified spatial and temporal profiles of three previously identified mechanical stimuli for tissue differentiation-pressure, tensile strain and fluid flow-as well as another candidate stimulus-tissue dilatation (volumetric strain). Whereas pressure and fluid velocity throughout the regenerate decayed to less than 31% of initial values within 20 min following distraction, tissue dilatation increased with time, reaching steady state values as high as 43% strain. This dilatation created large reductions and large gradients in cell and ECM densities. When combined with previous findings regarding the effects of strain and of cell and ECM densities on cell migration, proliferation and differentiation, these results indicate two mechanisms by which tissue dilatation may be a key stimulus for bone regeneration: (1) stretching of cells and (2) altering cell and ECM densities. These results are used to suggest experiments that can provide a more mechanistic understanding of the role of tissue dilatation in bone regeneration.
Sun, Zongyang; Rafferty, Katherine L; Egbert, Mark A; Herring, Susan W
Micromovement at a fracture or distraction osteogenesis (DO) site may play a significant role in bone formation and healing. Mastication is an important physiological process that can cause substantial micromovement at a mandibular disjunction. The purpose of this study is to characterize and quantify the micromovement caused by mastication. Eighteen pigs, divided into three groups based on duration of consolidation, received a unilateral (right) mandibular angle distraction osteogenesis protocol. Differential variable reluctance transducers (DVRTs) and ultrasound crystals were used to measure the change of gap width as well as interfragmentary movement during mastication. Synchronized chewing video and interfragmentary movement recordings were used to determine the magnitude and direction of micromovement at different phases of the chewing cycle. The magnitude of micromovement did not increase significantly with distraction up to almost 5 mm, but did decrease gradually with consolidation. The average micromovement magnitude during the distraction phase was 0.2-0.3 mm, equaling 50,000-250,000 microstrain (muepsilon) on interfragmentary tissue. The dominant deformation pattern was bending in the sagittal plane. The most common direction of bending at the power stroke of chewing was concave dorsally, i.e., superior shortening and inferior lengthening. These findings elucidate how masticatory mechanics affect a mandibular distraction site, and the measurements may be useful for future simulation studies.
Stucki-McCormick, S U; Fox, R M; Mizrahi, R D
The process of slow bone expansion by distraction osteogenesis in conjunction with functional remodeling can also be used for the reconstruction of a neomandible and neocondyle. This is the technique of transport distraction osteogenesis. A transport disc is surgically created adjacent to the area of a discontinuity defect, and the transport disc is advanced by the process of distraction osteogenesis, using the Ilizarov principles. The mandible therefore acts as the bony template for reconstruction such that the neomandible created from the distraction process has the same size and shape as the native mandible covered by gingiva. This allows for enhanced prosthetic reconstruction. A reverse-L osteotomy of the ramus can also be performed to create a transport disc to reconstruct a neocondyle. Because the leading edge of the transport disc becomes enveloped by a fibrocartilagenous cap, the ramal transport disc can be moved superiorly to create a new articulation. Patients are encouraged to open and close their mouths during the distraction process, such that the transport disc remodels to form a neocondyle. This technique was successfully used to treat patients with degenerative joint disease, condylar resorption, and bony ankylosis.
Griffin, Russell; Huisingh, Carrie; McGwin, Gerald
Objective Recent research has suggested that driver distraction is a major cause of driving performance impairment and motor vehicle collisions. Research on the topic has focused on passenger vehicles, with studies suggesting that drivers may be distracted nearly 33% of the time spent driving. To date, no study has examined the prevalence of distraction specifically among public transit bus drivers. Methods Over a three-month period, trained investigators observed and recorded distraction behaviors of bus drivers. Distraction prevalence was compared by route characteristics (e.g., geographic area, travel speed) using chi-square test. A general estimating equation logistic regression was used to estimate p-values for distraction prevalence by driver demographics. Results Overall, there was a 39% prevalence of distraction. The most prevalent distractions were due to interactions with another passenger. Distractions were more prevalent among drivers <30 years of age or ≥50 years of age, on city streets or highways (relative to residential streets), and when there were more than 20 passengers. Distractions were the least prevalent in suburban areas, with the highest prevalence observed in city centers and rural areas. Conclusions Driver distraction is a common problem for public transit bus drivers, mainly due to other passengers. Drivers should be educated on the hazards of distracted driving and on ways to avoid distraction. PMID:24433192
Lanzer, Martin; Pejicic, Rada; Kruse, Astrid L; Schneider, Thomas; Grätz, Klaus W; Lübbers, Heinz-Theo
The removal of wisdom teeth is one of the most common interventions in oral surgery. In order to avoid complications, a profound knowledge of the anatomy of teeth and adjacent tissues is crucial. In the case of maxillary wisdom teeth, their relationship to the maxillary sinus, to the pterygoid fossa, to the maxillary tuber and the adjacent venous plexus is particularly important. Three-dimensional (3D) imaging, for example by means of cone beam computed tomography (CBCT), is increasingly utilized in practice. However, the necessity of CBCT imaging is still a matter of intensive debate. The aim of this study was to describe the anatomic (positional) variation of maxillary wisdom teeth and, based on these findings, to elucidate the additional benefit of such imaging. A retrospective case study was performed using patients examined by means of CBCT imaging in the Department of Dento-Maxillofacial Radiology during the period from 2008 to 2013. Primary study variables comprised the spatial relationship of the teeth to the maxillary sinus, the degree of retention and root development, the covering of the root with bone and mucosa, the root configuration, and the developmental stage of the tooth. In addition, the association of the inclination of teeth in the transversal and sagittal plane with the above variables was evaluated. Descriptive statistical parameters were calculated for all results of the examination. In total, CBCT recordings of 713 maxillary wisdom teeth from 430 patients were evaluated. Their mean age was 29.8 years, and the proportion of male patients slightly prevailed (54.4%). Most teeth exhibited fully developed roots (64.1%). Overall 22.9% of third molars were impacted, 32.3% were retained, and 6.5% were erupting. In more than a third of the patients, wisdom teeth were in occlusion. The inclination of the third molars both in the transversal and sagittal plane was significantly associated with the distance of the root from the maxillary sinus as well
Brown, N M; Hellman, M; Haughom, B H; Shah, R P; Sporer, S M; Paprosky, W G
A pelvic discontinuity occurs when the superior and inferior parts of the hemi-pelvis are no longer connected, which is difficult to manage when associated with a failed total hip replacement. Chronic pelvic discontinuity is found in 0.9% to 2.1% of hip revision cases with risk factors including severe pelvic bone loss, female gender, prior pelvic radiation and rheumatoid arthritis. Common treatment options include: pelvic plating with allograft, cage reconstruction, custom triflange implants, and porous tantalum implants with modular augments. The optimal technique is dependent upon the degree of the discontinuity, the amount of available bone stock and the likelihood of achieving stable healing between the two segments. A method of treating pelvic discontinuity using porous tantalum components with a distraction technique that achieves both initial stability and subsequent long-term biological fixation is described.
Krishnan, Nagarajan; Ramamoorthy, Nathan; Panchanathan, Suresh; Balasundaram, Jothiramalingam S
Periorbital soft tissue swelling may result due to primary orbital pathology or from adjacent facio-maxillary or sino-nasal inflammatory causes. Osteomyelitis of maxilla in the pediatric age group is a rare entity in this era of antibiotics. We present an 11-month-old female infant who was brought with peri-orbital selling and purulent nasal discharge. Computed Tomography showed erosions of the walls of maxillary sinus suggestive of osteomyelitis. Culture of sinus scraping showed Staphylococcus aureus growth and the child improved with intravenous cloxacillin therapy. This case is presented due to the rarity of its presentation in this age group and for awareness to consider this entity in children having fever and peri-orbital swelling. PMID:25191055
Soofi, Zahid Iqbal; Yazdanie, Nazia; Kazmi, Syed Murtaza Raza
Patients reporting with large maxillary defects pose great difficulty in prosthodontic practice. After thorough history and clinical examination, prosthetic rehabilitation of these patients usually starts with an impression. In such cases conventional single step impression technique solely may not give the desired results. If the defect is of large size then impression making becomes difficult and complicated procedure. Therefore, conventional impression technique can be modified according to the needs and requirements. This report describes a modified and innovative technique of making impression in two parts, which can be withdrawn from mouth in two segments and easily reoriented outside the mouth.
Iyer, Subramania; Thankappan, Krishnakumar
Maxillary reconstruction is still an evolving art when compared to the reconstruction of the mandible. The defects of maxilla apart from affecting the functions of the speech, swallowing and mastication also cause cosmetic disfigurement. Rehabilitation of the form and function in patients with maxillary defects is either by using an obturator prosthesis or by a surgical reconstruction. Literature is abundant with a variety of reconstructive methods. The classification systems are also varied, with no universal acceptance of any one of them. The oncologic safety of these procedures is still debated, and conclusive evidence in this regard has not emerged yet. Management of the orbit is also not yet addressed properly. Tissue engineering, that has been hyped to be one of the possible solutions for this vexing reconstructive problem, has not come out with reliable and reproducible results so far. This review article discusses the rationale and oncological safety of the reconstructing the maxillary defects, critically analyzes the classification systems, offers the different reconstructive methods and touches upon the controversies in this subject. The management of the retained and exenterated orbit associated with maxillectomy is reviewed. The surgical morbidity, complications and the recent advances in this field are also looked into. An algorithm, based on our experience, is presented. PMID:24987199
Gungor, Ahmet Yalcin; Turkkahraman, Hakan
The volume of air passing through the nose and nasopharinx is limited by its shape and diameter. Continuous airflow through the nasal passage during breathing induces a constant stimulus for the lateral growth of maxilla and for lowering of the palatal vault. Maxillary morphological differences exist between patients with airway problems and control groups, identifying a potential etiological role in these patients. The purpose of this article was to review the literature on the interaction between airway problems and expressed maxillary morphology including specific dental and skeletal malocclusions. Statistically significant differences were found between patients with airway problems and control groups, in maxillary skeletal morphology including shorter maxillary length, more proclined maxillary incisors, thicker and longer soft palate, narrower maxillary arch and higher palatal vault. PMID:19756202
Jiménez-Moreno, R.; Orjuela, S. A.; Van Hese, P.; Prieto, F. A.; Grisales, V. H.; Philips, W.
Fatigue and distraction effects in drivers represent a great risk for road safety. For both types of driver behavior problems, image analysis of eyes, mouth and head movements gives valuable information. We present in this paper a system for monitoring fatigue and distraction in drivers by evaluating their performance using image processing. We extract visual features related to nod, yawn, eye closure and opening, and mouth movements to detect fatigue as well as to identify diversion of attention from the road. We achieve an average of 98.3% and 98.8% in terms of sensitivity and specificity for detection of driver's fatigue, and 97.3% and 99.2% for detection of driver's distraction when evaluating four video sequences with different drivers.
Patterson, Ryan W; Seitz, William H
Symbrachydactyly describes a spectrum of congenital hand differences consisting of digital loss resulting in fused short fingers. As the principles for distraction lengthening have evolved, the technique of nonvascularized toe phalangeal transfer to the hand with shortened digits has provided patients with improved outcomes. Nonvascularized toe phalanx to hand transplant with distraction lengthening restores functional length to a skeletally deficient, poorly functioning hand while maintaining an overlying layer of vascular and sensate tissue. The primary goal is improvement of digital length to enhance mechanical advantage and prehension. We describe the technique of nonvascularized toe phalangeal transfer and distraction lengthening for symbrachydactyly, including the following steps: nonvascularized proximal toe phalanx harvest, toe phalanx transfer to hand, pin placement, osteotomy, and closure.
Wood, Greg; Wilson, Mark R
When facing penalty kicks in football (soccer), goalkeepers frequently incorporate strategies that are designed to distract the kicker. However, no direct empirical evidence exists to ascertain what effect such visual distractions have on the attentional control, and performance, of footballers. Eighteen experienced footballers took five penalty kicks under counterbalanced conditions of threat (low vs. high) and goalkeeper movement (stationary vs. waving arms) while wearing eye-tracking equipment. Results suggested that participants were more distracted by a moving goalkeeper than a stationary one and struggled to disengage from a moving goalkeeper under situations of high threat. Significantly, more penalties were saved on trials when the goalkeeper was moving and shots were also generally hit closer to the goalkeeper (centrally) on these trials. The results provide partial support for the predictions of attentional control theory and implications for kickers and goalkeepers are discussed.
Esteves, Lucas Senhorinho; dos Santos, Jean Nunes; Sullivan, Steven M.; Martins, Luana Maria Rosário; Ávila, Carolina
Introduction: Maxillary surgery on a bone segment enables movement in the sagittal and vertical planes. When performed on multiple segments, it further provides movement in the transverse plane. Typical sites for interdental osteotomies are between laterals and canines, premolars and canines, or between incisors. Additionally, osteotomies can be bilateral, unilateral or asymmetric. The ability to control intercanine width, buccolingual angulation of incisors, and correct Bolton discrepancy are some of the advantages of maxillary segmentation between laterals and canines. Objective: This article describes important features to be considered in making a clinical decision to segment the maxilla between laterals and canines when treating a dentoskeletal deformity. It further discusses the history of this surgical approach, the indications for its clinical use, the technique used to implement it, as well as its advantages, disadvantages, complications and stability. It is therefore hoped that this paper will contribute to disseminate information on this topic, which will inform the decision-making process of those professionals who wish to make use of this procedure in their clinical practice. Conclusions: Segmental maxillary osteotomy between laterals and canines is a versatile technique with several indications. Furthermore, it offers a host of advantages compared with single-piece osteotomy, or between canines and premolars. PMID:27007769
for patients with transverse facial asymmetries by displacement of the maxillary dentition . 5 2.2 INTRODUCTION A generally accepted principle of smile...altered by digitally translating the teeth around the original arch form, not by transversely moving the maxillary dentition as a single unit. As the...horizontal position of the maxillary dentition can be used to camouflage facial discrepancies in the transverse plane. The purpose of this study was to
Zhang, W B; Yu, Y; Wang, Y; Liu, X J; Mao, C; Guo, C B; Yu, G Y; Peng, X
The maxilla is the most important bony support of the mid-face skeleton and is critical for both esthetics and function. Maxillary defects, resulting from tumor resection, can cause severe functional and cosmetic deformities. Furthermore, maxillary reconstruction presents a great challenge for oral and maxillofacial surgeons. Nowadays, vascularized composite bone flap transfer has been widely used for functional maxillary reconstruction. In the last decade, we have performed a comprehensive research on functional maxillary reconstruction with free fibula flap and reported excellent functional and acceptable esthetic results. However, this experience based clinical procedure still remainssome problems in accuracy and efficiency. In recent years, computer assisted techniques are now widely used in oral and maxillofacial surgery. We have performed a series of study on maxillary reconstruction with computer assisted techniques. The computer assisted techniques used for maxillary reconstruction mainly include: (1) Three dimensional (3D) reconstruction and tumor mapping: providing a 3D view of maxillary tumor and adjacent structures and helping to make the diagnosis of maxillary tumor accurate and objective; (2) Virtual planning: simulating tumor resection and maxillectomy as well as fibula reconstruction on the computer, so that to make an ideal surgical plan; (3) 3D printing: producing a 3D stereo model for prebending individualized titanium mesh and also providing template or cutting guide for the surgery; (4) Surgical navigation: the bridge between virtual plan and real surgery, confirming the virtual plan during the surgery and guarantee the accuracy; (5) Computer assisted analyzing and evaluating: making a quantitative and objective of the final result and evaluating the outcome. We also performed a series of studies to evaluate the application of computer assisted techniques used for maxillary reconstruction, including: (1) 3D tumor mapping technique for accurate
Eley, Karen A; Witherow, Helen; Hayward, Richard; Evans, Robert; Young, Karen; Clark, Allan; Dunaway, David
Frontofacial advancement by distraction osteogenesis using the rigid external distraction device has become an accepted treatment for the deformity associated with craniofacial dysostoses (e.g., Crouzon, Apert, and Pfeiffer syndromes). The technical and physiological principles of osteogenesis distraction are well understood. This study documents the pattern of calcification at the osteotomy sites after distraction by analysis of serial three-dimensional computed tomography (CT) scans. The CT scans of 25 patients (11 with Crouzon, 6 with Apert, and 8 with Pfeiffer syndrome) were analyzed. Eleven individual areas along the osteotomy lines were assessed for evidence of bone formation. Scores were assigned within 4 categories ranging from no bone, calcification without bridge formation, a bony bridge, to complete bony infill (>95%). The scans were reviewed on 2 separate occasions by 2 independent assessors. There was high concordance both for intraobserver and interobserver scores. Rigid external distraction frame removal was undertaken after a 6-week consolidation period. All CT scan timings were calculated from this date. Of the 25 patients studied, 16 patients had CT scans available at 3 to 6 months, 12 at 9 to 12 months, and 7 at or more than 18 months. The scans were available in standard coronal slices with three-dimensional reconstructions. Bone formation is most consistently seen in the pterygoid region with calcification consistently occurring earlier and more completely in this area. Bone formation was often delayed in the orbital region and severely delayed or absent in the frontal region and zygomatic arches. There was no significant difference in the order or quality of bony union for the 3 underlying craniofacial dysostoses. This preliminary study confirms the clinical impression that bone formation after distraction is greatest in the pterygoid regions. The clinical implications of these findings are discussed.
Hoff, Jane; Grell, Jennifer; Lohrman, Nicole; Stehly, Christy; Stoltzfus, Jill; Wainwright, Gail; Hoff, William S
Distracted driving, a significant public safety issue, is typically categorized as cell phone use and texting. The increase of distracted driving behavior (DDB) has resulted in an increase in injury and death. The purpose of this study was to identify the frequency and perception of DDB in adults. A 7-question SurveyMonkey questionnaire was distributed to a convenience sample of adults. Standard demographics included age, gender, and highest levels of education. Primary outcome questions were related to frequency of DDB, and overall perceptions specific to distracted driving. Results were compared on the basis of demographics. Chi-square testing and the Kruskal-Wallis analysis of variance were applied, with statistical significance defined as P ≤ .05. There were 1857 respondents to the survey: 1721 were aged 23-64 years (93%); 1511 were women (81%); 1461 had high school education or greater (79%). A total of 168 respondents (9%) reported being involved in a car accident while distracted. The highest reported frequency of DDB included cell phone use (69%), eating/drinking (67%), and reaching for an object in the care (49%). Younger age (18-34 years) and higher level of education (bachelor's degree or greater) were statistically associated with these DDB; gender demonstrated no statistical significance. Text messaging was reported by 538 respondents (29%), with a statistically significant association with age (18-34 years), higher education (bachelor's degree or greater), and gender (males). A total of 1143 respondents (63%) believed that they could drive safely while distracted. This study demonstrates that DDB in adults is not restricted to reading and sending text messages. Moreover, these results indicated that people fail to perceive the dangers inherent in distracted driving. Prevention and outreach education should not be limited to texting and cell phone use but should target all forms of DDB. The age group 18-34 years should be the primary target in the
Hassani, Sahar; Kelly, Erin H; Smith, Jennifer; Thorpe, Sara; Sozzer, Fatima H; Atchley, Paul; Sullivan, Elroy; Larson, Dean; Vogel, Lawrence C
Based on the National Highway Traffic Safety Association's (NHTSA) Report, fatalities due to distracted driving are on the rise and the highest proportion of fatalities by age group is the 20-29 year old category. To date little has been done to educate college students about the dangers of distracted driving and engage these students in promoting a safe driving culture. Intervening among college students has the potential for making real-time behavior change, can foster a lifetime of safe driving habits among these students, and can help contribute to a culture of safe driving that can be created and sustained through positive messages from peers. The goals of this study were to develop, implement and evaluate a distracted driving presentation for college students to change knowledge, attitude and behavior on distracted driving. A 30-min, multi-media presentation on distracted driving was presented to 19 colleges and universities, totaling 444 college students (mean age 23.7±7.0 years of age, 61% females, 39% males). Students completed three surveys: prior to the workshop (interview 1), immediately after the workshop (interview 2), and 3 months following the workshop (interview 3). We assessed changes between interview 1 and interview 2 and found 15 of the 15 attitude-knowledge based questions significantly improved after the course. In addition, we assessed changes from interviews 1 and 3, and found 11 of the 15 attitude-knowledge based questions maintained their significance. Responses to behavior related questions at three months were also compared to baseline, and significant improvements were found for 12 of the 14 questions. While this study was successful in improving the short-term attitude-knowledge and behaviors on distracted driving, work is needed to sustain (and evaluate) long-term effects.
Zhang, Jincai; Xu, Pingping
Objective The present study sought to establish an animal model to study the feasibility and safety of rapid retraction of maxillary anterior teeth en masse aided by alveolar surgery in order to reduce orthodontic treatment time. Method Extraction of the maxillary canine and alveolar surgery were performed on twelve adult beagle dogs. After that, the custom-made tooth-borne distraction devices were placed on beagles' teeth. Nine of the dogs were applied compression at 0.5 mm/d for 12 days continuously. The other three received no force as the control group. The animals were killed in 1, 14, and 28 days after the end of the application of compression. Results The tissue responses were assessed by craniometric measurement as well as histological examination. Gross alterations were evident in the experimental group, characterized by anterior teeth crossbite. The average total movements of incisors within 12 days were 4.63±0.10 mm and the average anchorage losses were 1.25±0.12 mm. Considerable root resorption extending into the dentine could be observed 1 and 14 days after the compression. But after consolidation of 28 days, there were regenerated cementum on the dentine. There was no apparent change in the control group. No obvious tooth loosening, gingival necrosis, pulp degeneration, or other adverse complications appeared in any of the dogs. Conclusions This is the first experimental study for testing the technique of rapid anterior teeth retraction en masse aided by modified alveolar surgery. Despite a preliminary animal model study, the current findings pave the way for the potential clinical application that can accelerate orthodontic tooth movement without many adverse complications. Clinical Relevance It may become a novel method to shorten the clinical orthodontic treatment time in the future. PMID:22039479
Huisingh, Carrie; Griffin, Russell; McGwin, Gerald
Objective Distracted driving contributes to a large proportion of motor vehicle crashes, yet little is known about the prevalence of distracted driving and the specific types of distracting behaviors. The objective of this study was to estimate the prevalence of driver distraction using a roadside observational study design. Methods A cross-sectional survey involving direct roadside observation was conducted at 11 selected intersections. Trained investigators observed a sample of passenger vehicles and recorded distraction-related behaviors, driver characteristics, and contextual factors such as vehicle speed and traffic flow. Results Of the 3,265 drivers observed, the prevalence of distracted driving was 32.7%. Among those involved in a distracting activity, the most frequently observed distractions included interacting with another passenger (53.2%, where passengers were present), talking on the phone (31.4%), external-vehicle distractions (20.4%), and texting/dialing a phone (16.6%). The prevalence of talking on the phone was higher among females than males (38.6% vs. 24.3%), whereas external vehicle distractions were higher among males than females (25.8% vs. 24.3%). Drivers <30 years were observed being engaged in any distracting activity, interacting with other passengers and texting/dialing more frequently than drivers aged 30–50 and >50 years. Drivers were engaged in distracting behaviors more frequently when the car was stopped. Conclusions When using similar methodology, roadside observational studies generate comparable prevalence estimates of driver distraction as naturalistic driving studies. Driver distraction is a common problem among passenger vehicle drivers. Despite the increased awareness on the dangers of texting and cell phone use while driving, these specific activities were two of the most frequently observed distractions. There is a continued need for road safety education about the dangers of distracted driving, especially for younger
Kuhns, Benjamin D.; Erickson, Brandon J.; Bressler, Leah R.; Sarmast, Sara M.; Nho, Shane J.
Hip distraction is necessary for safe arthroscopic entry into the hip joint. Achieving sufficient distraction is difficult in exceedingly tall patients (>190.5 cm) because of size limitations of currently available hip distraction systems. Inadequate distraction can delay the surgical procedure and potentially lead to complications. By repurposing a foam head-positioning block, we report a safe and inexpensive positioning technique for extending the traction distance for tall patients by 2 inches. PMID:26870657
Li, Jan-Mou; Malikopoulos, Andreas; Thakur, Gautam; Vatsavai, Raju
In this paper, we present the results obtained and insights gained through the analysis of TRB contest data. We used exploratory analysis, regression, and clustering models for gaining insights into the driver behavior in a dilemma zone while driving under distraction. While simple exploratory analysis showed the distinguishing driver behavior patterns among different popu- lation groups in the dilemma zone, regression analysis showed statically signification relationships between groups of variables. In addition to analyzing the contest data, we have also looked into the possible impact of distracted driving on the fuel economy.
Maia, Luiz Guilherme Martins; Monini, André da Costa; Jacob, Helder Baldi; Gandini, Luiz Gonzaga
One of the characteristics of diabetes mellitus is the exaggerated inflammatory response. The present report shows the reaction from the use of a rapid maxillary expander in a diabetic patient. A 9-year-old child presented an uncommon reaction to the treatment with a rapid maxillary expander, and on follow-up examination, it was discovered that the patient had diabetes mellitus. After controlling the disease, the proposed treatment was used without further incidents. The case calls attention to the presence of uncommon responses to treatment and the need for the orthodontist to suspect a patient's systemic compromise.
Colletti, Giacomo; Felisati, Giovanni; Biglioli, Federico; Tintinelli, Roberto; Valassina, Davide
A fungus ball is one of the fungal diseases that can affect the paranasal sinuses. It requires surgical treatment. Because there is only one previously reported case of dental implant placement after treatment of a maxillary sinus fungus ball, the authors here report on a case of a maxillary sinus fungus ball with bone erosion that was treated surgically with a combined endoscopic endonasal and endoral (Caldwell-Luc) approach. One year later, a graft from the ilium was obtained and a sinus elevation was performed to allow the placement of dental implants. Three months later, the dental implants were placed, and they were all osseointegrated at the 9-month follow-up.
...The National Highway Traffic Safety Administration (NHTSA) is concerned about the effects of distraction due to drivers' use of electronic devices on motor vehicle safety. Consequently, NHTSA is issuing nonbinding, voluntary NHTSA Driver Distraction Guidelines (NHTSA Guidelines) to promote safety by discouraging the introduction of excessively distracting devices in vehicles. This notice......
Xu, Jianzhong; Fan, Xitao; Du, Jianxia
The goal of the current investigation was to evaluate psychometric properties of the Homework Distraction Scale (HDS) using 796 middle school students. Results from confirmatory factor analyses (CFAs) supported the presence of two distinct yet related subscales for the HDS: Conventional Distraction and Tech-Related Distraction. Results of…
Smith, Kalynda; Craig-Henderson, Kellina
The present study investigated the effect of cognitive distraction on the endorsement of gender role stereotypes in one sample of African American female participants. Participants' awareness and endorsement of gender role stereotypes for male and females was assessed. Following random assignment to distraction or no distraction conditions, they…
Koppel, Sjaan; Charlton, Judith; Kopinathan, Chelvi; Taranto, David
Driver distraction represents a well-documented and growing contribution to the road safety problem. This study used a naturalistic, observational approach to examine if children in vehicles are a significant source of driving distraction. Families with children aged between 1 and 8 years drove an instrumented "study vehicle" on their regular trips for 3 weeks. A discrete video recording system in the vehicle provided images of the driver and front seat passenger, the rear seat child passengers and the traffic ahead. The video-recordings inside and outside the vehicle were analysed to identify potential distracting activities, where 'distraction' was broadly defined as any activity that distracted the driver or competed for their attention while driving. In addition, all potentially distracting activities that involved the driver looking away from the forward roadway for more than 2s while the vehicle was in motion were also coded. Video-recordings were analysed for 92 driving journeys undertaken by 12 families including 25 children and 19 drivers. The mean journey duration was approximately 16 min (range: 2 min-3h 34 min). Most journeys were undertaken during the day (89%), with the mother driving (65%) and without a front seat passenger (64%). Driving journeys were predominantly undertaken in urban areas (97%), on suburban roads/streets (94%), and under low complexity traffic conditions (91%). Most journeys involved some source of potential driver distraction (98%), with drivers distracted for 18% of the driving journey. The most frequent types of distracting activities that drivers engaged in included: touching their head or their face (35%), interacting with child passengers in the rear seat (12%), and engaging with the front seat passenger (9%). Almost three-quarters of these potentially distracting activities were engaged in by the driver while the study vehicle was in motion (72%) and 14% of all potentially distracting activities involved the driver's eyes
Zacks, Jeffrey M.; Swallow, Khena M.
One way to understand something is to break it up into parts. New research indicates that segmenting ongoing activity into meaningful events is a core component of ongoing perception, with consequences for memory and learning. Behavioral and neuroimaging data suggest that event segmentation is automatic and that people spontaneously segment activity into hierarchically organized parts and sub-parts. This segmentation depends on the bottom-up processing of sensory features such as movement, and on the top-down processing of conceptual features such as actors’ goals. How people segment activity affects what they remember later; as a result, those who identify appropriate event boundaries during perception tend to remember more and learn more proficiently. PMID:22468032
Cerón-Zapata, A M; López-Palacio, A M; Rodriguez-Ardila, M J; Berrio-Gutiérrez, L M; De Menezes, M; Sforza, C
To compare the three-dimensional changes occurring in the maxillary arch during the use of modified pre-surgical nasoalveolar moulding (PNAM) and Hotz's plate. A clinical trial including 32 children with unilateral cleft lip and palate (UCLP), 16 treated with Hotz's plate and 16 with PNAM, was performed. Impressions of the maxillary arches were taken: A. prior to pre-surgical orthopaedics, B. before cheiloplasty and C. after cheiloplasty. Models were digitised using a stereophotogrammetric instrument, and geodesic distances were calculated: anterior, canine and posterior widths of the arch, and lengths and cleft depths of the larger and shorter segments. The time and treatment effects were assessed by two-factor anova. A significant effect of treatment was found for cleft depth at the larger segment: children treated with Hotz's plate had significantly deeper cleft than children treated with PNAM. All distances significantly changed during time: the anterior and canine widths decreased, while the posterior width, the lengths and depths of the cleft segments increased. Significant treatment per time interactions was found. The anterior and canine widths reduced more with PNAM between time points A and B while Hotz's treatment was more effective between B and C. The shorter segment depth increased more between B and C with PNAM, and between A and B with Hotz's plate. During pre-surgical orthopaedics, therapy with PNAM obtained the best results in reducing the width at the anterior segment of the cleft. This treatment gave a lower increase in cleft depth than treatment with Hotz's plate.
Vaz, Paula; Faria-Almeida, Ricardo; Braga, Ana-Cristina; Felino, António
Background Proximity of the dental roots to the sinus floor makes dental disease a probable cause of maxillary sinusitis. The aim of this study was to find out if maxillary sinus pathologic changes were more prevalent in patients with dental disease and to evaluate the performance of computed tomography (CT) in analyzing and detecting apical periodontitis and other odontogenic causes on the maxillary sinusitis etiology in a Portuguese Caucasian population. Material and Methods Retrospective cohort study. The total sample of 504 patients and their CT was included in this study. The patients were from a private dental clinic, specializing in oral surgery, where the first complaint was not directly related to sinus disease, but with dental pathology. For each patient, the etiological factors of maxillary sinusitis and the imaging CT findings were analyzed. All the axial, coronal and sagittal CT slices were evaluated and general data were registered. The latter was selected based on the maxillary sinus CT published literature. Results 32.40% of patients presented normal sinus (without any etiological factor associated), 29.00% showed presence of etiological and imaging findings in the maxillary sinus, 20.60% had only imaging changes in the maxillary sinus and 18.00% of patients presented only etiological factors and no change in the maxillary sinus. Conclusions Radiological imaging is an important tool for establishing the diagnosis of maxillary sinus pathology. These results indicate that the CT scan should be an excellent tool for complement the odontogenic sinusitis diagnosis. Key words: Maxillary sinusitis/etiology, odontogenic, computed tomography, maxillary sinus. PMID:25858084
Khan, Ahmed; Fareed, Wamiq Musheer; Tandon, Parul; Zafar, Muhammad Sohail
Abstract Temporomandibular joint ankylosis, a debilitating disease mainly affecting children, is characterized by progressive restriction of mouth opening and maxilla-mandibular developmental deformities. Craniofacial distraction osteogenesis has been developed as a standard surgical strategy for rectification of craniofacial deformities. The purpose of this study was to assess mono-planar distraction devices for the correction of various mandibular asymmetries in patients with unilateral temporomandibular joint ankylosis who developed restricted mouth opening and mandibular retrognathia. All patients were treated using one-stage distraction osteogenesis followed by temporalis fascia interpositional arthroplasty under general anesthesia. A significant increase in mandibular ramus and base length was observed. Although an increase in anterior lower facial height was observed, it was not significant statistically. A decrease in posterior lower facial height and corpus was observed. Oblique distraction with angular osteotomy allowed lengthening of both the ramus and corpus, yielding satisfactory results and hence eliminating the need of secondary surgery. In conclusion, univector internal distractors are effective for correction of multi-planar mandibular deficiencies by optimizing its placement through meticulous planning. PMID:26243521
Liu, Z; Luyten, F P; Lammens, J; Dequeker, J
The process of fracture healing has been described in detail in many histological studies. Recent work has focused on the mechanisms by which growth and differentiation factors regulate the fracture healing process. Rapid progress in skeletal cellular and molecular biology has led to the identification of many signaling molecules associated with the formation of skeletal tissues, including members of the transforming growth factor-beta (TGF-beta) superfamily and the insulin-like growth factor (IGF) family. Increasing evidence indicates that they are critical regulators of cellular proliferation, differentiation, extracellular matrix biosynthesis and mineralization. Limb lengthening procedure (distraction osteogenesis) is a relevant model to investigate the in vivo correlation between mechanical stimulation and biological responses as the callus is stretched by a proper rate and rhythm of mechanical strain. This model also provides additional insights into the molecular and cellular events during bone fracture repair. TGF-beta 1 was significantly increased in both the distracted callus and the fracture callus. The increased level of TGF-beta 1, together with a low concentration of calcium and an enhanced level of collagen synthesis, was maintained in the distracted callus as long as mechanical strain was applied. Less mineralization is also associated with a low level of osteocalcin production. These observations provide further insights into the molecular basis for the cellular events during distraction osteogenesis.
McCarthy, Joseph G; Hopper, Richard A; Hollier, Larry H; Peltomaki, Timo; Katzen, Timothy; Grayson, Barry H
Initial clinical experience with distraction osteogenesis has demonstrated the risk of developing postdistraction malocclusion that requires secondary orthodontic correction. In addition, optimal mandibular form is not always achieved. Both animal studies and preliminary clinical investigations have suggested that the regenerate can be successfully "molded" during active mandibular distraction. The authors have applied this concept clinically to obtain a more desirable occlusal relationship in a group of mandibular distraction patients. Eleven patients are described in whom angulation of the distraction device or intermaxillary/interdental elastics were employed to mold the regenerate. Two representative case studies are provided to illustrate the principles. When using elastic traction to close an anterior open bite, care must be taken that extrusion of individual teeth is minimized by distributing the force over the entire dental arch, especially the basilar portions of the jaws. The authors demonstrate that molding of the regenerate can be successfully accomplished not only during device activation but also early in the consolidation period. The outer limit of the time window in which molding is effective remains to be defined.
Marsh, John E.; Hughes, Robert W.; Jones, Dylan M.
Five experiments demonstrate auditory-semantic distraction in tests of memory for semantic category-exemplars. The effects of irrelevant sound on category-exemplar recall are shown to be functionally distinct from those found in the context of serial short-term memory by showing sensitivity to: The lexical-semantic, rather than acoustic,…
Weissman, D H; Warner, L M; Woldorff, M G
The neural circuitry that increases attention to goal-relevant stimuli when we are in danger of becoming distracted is a matter of active debate. To address several long-standing controversies, we asked participants to identify a letter presented either visually or auditorily while we varied the amount of cross-modal distraction from an irrelevant letter in the opposite modality. Functional magnetic resonance imaging revealed three novel results. First, activity in sensory cortices that processed the relevant letter increased as the irrelevant letter became more distracting, consistent with a selective increase of attention to the relevant letter. In line with this view, an across-subjects correlation indicated that the larger the increase of activity in sensory cortices that processed the relevant letter, the less behavioral interference there was from the irrelevant letter. Second, regions of the dorsolateral prefrontal cortex (DLPFC) involved in orienting attention to the relevant letter also participated in increasing attention to the relevant letter when conflicting stimuli were present. Third, we observed a novel pattern of regional specialization within the cognitive division of the anterior cingulate cortex (ACC) for focusing attention on the relevant letter (dorsal ACC) versus detecting conflict from the irrelevant letter (rostral ACC). These findings indicate novel roles for sensory cortices, the DLPFC, and the ACC in increasing attention to goal-relevant stimulus representations when distracting stimuli conflict with behavioral objectives. Furthermore, they potentially resolve a long-standing controversy regarding the key contribution of the ACC to cognitive control.
Khan, Ahmed; Fareed, Wamiq Musheer; Tandon, Parul; Zafar, Muhammad Sohail
Temporomandibular joint ankylosis, a debilitating disease mainly affecting children, is characterized by progressive restriction of mouth opening and maxilla-mandibular developmental deformities. Craniofacial distraction osteogenesis has been developed as a standard surgical strategy for rectification of craniofacial deformities. The purpose of this study was to assess mono-planar distraction devices for the correction of various mandibular asymmetries in patients with unilateral temporomandibular joint ankylosis who developed restricted mouth opening and mandibular retrognathia. All patients were treated using one-stage distraction osteogenesis followed by temporalis fascia interpositional arthroplasty under general anesthesia. A significant increase in mandibular ramus and base length was observed. Although an increase in anterior lower facial height was observed, it was not significant statistically. A decrease in posterior lower facial height and corpus was observed. Oblique distraction with angular osteotomy allowed lengthening of both the ramus and corpus, yielding satisfactory results and hence eliminating the need of secondary surgery. In conclusion, univector internal distractors are effective for correction of multi-planar mandibular deficiencies by optimizing its placement through meticulous planning.
Furnham, Adrian; Stephenson, Rebecca
The aim of this study was to ascertain the nature of the interaction between the affective value of musical distraction, personality type and performance on the cognitive tasks of reading comprehension, free recall, mental arithmetic and verbal reasoning in children aged 11-12 years. It was hypothesized that the cognitive performance of extraverts…
Geer, James H.; Fuhr, Robert
Four groups of male undergraduates were instructed to perform complex cognitive operations when randomly presented single digits of a dichotic listening paradigm. An erotic tape recording was played into the nonattended ear. Sexual arousal varied directly as a function of the complexity of the distracting cognitive operations. (Author)
Wetzel, Nicole; Widmann, Andreas; Schroger, Erich
Unexpected and task-irrelevant sounds can capture our attention and may cause distraction effects reflected by impaired performance in a primary task unrelated to the perturbing sound. The present auditory-visual oddball study examines the effect of the informational content of a sound on the performance in a visual discrimination task. The…
Simuntis, Regimantas; Kubilius, Ričardas; Ryškienė, Silvija; Vaitkus, Saulius
We present a case of odontogenic maxillary sinusitis whose sinonasal symptomatology was thought to be the consequence of a previous midfacial trauma. The patient was admitted to the Clinic of Oral and Maxillofacial Surgery after more than 10 years of exacerbations of sinonasal symptoms, which began to plague soon after a facial contusion. We decided to perform CT of paranasal sinuses, and despite the absence dental symptomatology, the dental origin of sinusitis was discovered. The majority of sinonasal symptoms resolved after appropriate dental treatment, and there was no need for nasal or sinus surgery.
Sreedharan, S; Krishnan, I S
Odontomas are considered to be the most common odontogenic tumors of the oral cavity. Some authors consider it as malformations rather than true neoplasms. The exact etiology of odontomes is still not known. Most odontomes are asymptomatic and are discovered during routine radiographic investigations. Odontomes generally cause disturbances in the eruption of the teeth, most commonly delayed eruption or deflection. The present report describes the surgical management of a case of compound odontoma in a 10-year-old boy who presented with a complaint of swelling in the maxillary right anterior region and retained deciduous incisors. The related literature is also being reviewed in this article.
Freitas, Renato da Silva; Alonso, Nivaldo; Busato, Luciano; D'oro, Ubiratã; Ferreira, Marcus Castro
For many years, surgeons have sought a method to treat severe facial deformities without using bone grafts and extensive surgery. Distraction osteogenesis offers this promise. The technique used in mandibular hypoplasia follows the basic principles proposed by Ilizarov which states that the device must be elongated 1 mm per day to create optimal bone production. Despite the widespread implementation of this recommendation to include the 1-mm/day separation, doubt still exists as to whether this is the optimal treatment regimen. Intraoral devices with percutaneous activator pins were used in 16 patients with hypoplastic mandibles. The results of distraction were documented by panorex and cephalogram of the mandible. The length of the ramus as well as multiple mandible dimensions and facial angles were measured. The panorex and cephalogram of the mandible were effective in demonstrating the significant increase in length of the mandible and ramus, as well as the entire mandible, but there was no correlation between the stretching obtained by the distraction device and that measured by the radiographic studies. The S-N-B angle was the only facial angle in which there is a statistically significant increase measured and this appeared to be related to a mandible rotation. It is concluded that the mandible distraction (using an intraoral device and an external activator pin) was effective in increasing the ramus length and both the panorex and the cephalogram were effective in demonstrating this morphologic change. There was no correlation between the clinical result and the radiographic studies demonstrating that the clinical judgment still has a significant role in controlling mandible distraction.
Fava, L R
A case is reported in which a perforation of the sinus floor of the maxillary sinus occurred with extrusion of a calcium hydroxide paste during routine root canal treatment of a maxillary premolar. All clinical manifestations are described as well as the results of a follow-up evaluation.
Rafferty, Katherine L.; Sun, Zongyang; Egbert, Mark; Bakko, Daniel W.; Herring, Susan W.
Objective: Loading of temporomandibular tissues during mandibular distraction may cause changes in condylar growth and cartilage thickness. This study examines the effects of distraction on the condyle in a large animal model by explicitly measuring growth and in vivo loading. Design: Unilateral mandibular distraction was carried out on twenty growing minipigs divided into three groups. One group underwent distraction but not consolidation, whereas the other two groups were allowed a period of consolidation of either one or two weeks. Animals received fluorochrome and 5-bromo-2'-deoxyuridine (BrdU) labeling and masticatory strain was measured from the condylar neck. Condylar strain was also recorded in an age-matched sample of eight animals that received no distraction surgery. Immunohistochemical procedures were used to identify dividing prechondroblasts and histological analysis was used to measure mineral apposition rate, count dividing cells, and measure the thickness of condylar cartilage. Results: Strain magnitude, particularly compressive strain, was much larger on the non-distraction side compared to the distraction side condyle. Compared to normal loading levels, the distraction side condyle was underloaded whereas the condyle on the intact side was overloaded. Mineral apposition and cartilage thickness were greater on the distraction side condyle compared to the opposite side. Differences between the sides were most pronounced in the group with no consolidation and became progressively reduced with consolidation time. Conclusions: Increased mineralization and cartilage thickness on the distraction side condyle is associated with reduced, not increased loading, perhaps because of disruption of the distraction side masseter muscle. PMID:17573035
Weeks, Jennifer C; Hasher, Lynn
Older adults show implicit memory for previously seen distraction, an effect attributed to poor attentional control. It is unclear whether this effect results from lack of control over encoding during the distraction task, lack of retrieval constraint during the test task, or both. In the present study, we simulated poor distraction control in young adults using divided attention at encoding, at retrieval, at both times, or not at all. The encoding task was a 1-back task on pictures with distracting superimposed letter strings, some of which were words. The retrieval task was a word fragment completion task testing implicit memory for the distracting words. Attention was divided using an auditory odd digit detection task. Dividing attention at encoding, but not at retrieval, resulted in significant priming for distraction, which suggests that control over encoding processes is a primary determinant of distraction transfer in populations with low inhibitory control (e.g. older adults).
Lee, Doksa; Ishii, Syoichiro; Yakushiji, Noboru
Iatrogenic tooth displacement is a rare complication during extraction of impacted molars, but displacement of a maxillary third molar into the maxillary sinus, infratemporal fossa, buccal space, pterygomandibular space, and lateral pharyngeal space has been reported. Currently, 6 published reports describe third molar displacement into the lateral pharyngeal space, only 1 of which involved the loss of a maxillary third molar into this area, which occurred after an attempted self-extraction by the patient. There have been no reported cases of iatrogenic displacement of the maxillary third molar during an extraction procedure. This article describes the recovery, under general anesthesia, of a maxillary third molar from the lateral pharyngeal space after an iatrogenic displacement.
This case report presents surgical endodontic management outcomes of maxillary incisors that were infected via the lateral canals. Two cases are presented in which endodontically-treated maxillary central incisors had sustained lateral canal infections. A surgical endodontic treatment was performed on both teeth. Flap elevation revealed vertical bone destruction along the root surface and infected lateral canals, and microscopy revealed that the lateral canals were the origin of the lesions. After the infected lateral canals were surgically managed, both teeth were asymptomatic and labial fistulas were resolved. There were no clinical or radiographic signs of surgical endodontic management failure at follow-up visits. This case report highlights the clinical significance and surgical endodontic management of infected lateral canal of maxillary incisor. It is important to be aware of root canal anatomy variability in maxillary incisors. Maxillary central incisors infected via the lateral canal can be successfully managed by surgical endodontic treatment. PMID:25671217
Bai, Jiayue; Zhang, Xin; Zhang, Di; Ding, Wenyuan; Shen, Yong; Zhang, Wei; Du, Mengzhen
Objective: A retrospective review was undertaken to evaluate the impact of over distraction on cervical axial symptoms (AS) after anterior cervical discectomy and fusion (ACDF). Methods: The retrospective review included 421 patients who underwent ACDF for one or two segments. Of these, 78 patients for whom complete follow-up data were available were selected for inclusion in the analysis. X-rays of the cervical vertebra were performed immediately after the surgery, 3 months postsurgery, and at a final follow up (6-24 months). According to the presence/absence of AS, the patients were divided into a symptom group (Group S) and a nonsymptom group (Group N). The ratio of intervertebral height change, change in the overall cervical curvature, change in the local curvature of the surgical segment, cervical total range of motion (ROM), and Japanese Orthopaedic Association (JOA) recovery rate were compared and analyzed. A linear regression analysis of the ratio of intervertebral height change and the symptom and severity of the AS according to the Visual Analogue Scale (VAS) was carried out. Results: The total incidence of AS was 33.97%. C5 nerve root palsy occurred in one case in Group S after the surgery. The neurologic symptoms of both groups were significantly alleviated after the surgery. The ratio of intervertebral height change in Group S was significantly higher than that in Group N at the last follow-up (P < 0.05). However, the changes in the overall cervical curvature, local curvature of the surgical segment, cervical ROM, and JOA recovery rates were not statistically significant (P > 0.05). In Group S, 37% of the patients had symptoms that occurred in the chest area, and the ratio of intervertebral height change was significantly positively correlated with the VAS score of the AS (r = 0.893). Conclusions: The occurrence of postoperative AS will significantly increase if the ratio of intervertebral height change of the surgical segment after ACDF is over 10
Golen, Rebecca B.; Ventura, Alison K.
Mindless eating, or eating while distracted by surrounding stimuli, leads to overeating. The present study explored whether “mindless feeding,” or maternal distraction during bottle-feeding, is associated with greater infant formula/milk intakes and lower maternal sensitivity to infant cues. Mothers and their ≤24-week-old bottle-feeding infants (N=28) visited our laboratory for a video-recorded feeding observation. Infant intake was assessed by weighing bottles before and after the feedings. Maternal sensitivity to infant cues was objectively assessed by behavioral coding of video-records using the Nursing Child Assessment Feeding Scale. Maternal distraction was defined as looking away from the infant >75% of the feeding; using a mobile device; conversing with another adult; or sleeping. Twenty-nine percent (n=8) of mothers were distracted. While differences in intakes for infants of distracted vs. not distracted mothers did not reach significance (p=0.24), the association between distraction and infant intake was modified by two dimensions of temperament: orienting/regulation capacity (p=0.03) and surgency/extraversion (p=0.04). For infants with low orienting/regulation capacity, infants of distracted mothers consumed more (177.1 ± 33.8 ml) than those of not distracted mothers (92.4 ± 13.8 ml). Similar findings were noted for infants with low surgency/extraversion (distracted: 140.6 ± 22.5 ml; not distracted: 78.4 ± 14.3 ml). No association between distraction and intake was seen for infants with high orienting/regulation capacity or surgency/extraversion. A significantly greater proportion of distracted mothers showed low sensitivity to infant cues compared to not distracted mothers (p=0.04). In sum, mindless feeding may interact with infant characteristics to influence feeding outcomes; further experimental and longitudinal studies are needed. PMID:25953601
Angiero, Francesca; Borloni, Roberto; Macchi, Maurizia; Stefani, Michele
Ameloblastic carcinoma is a very rare malignant odontogenic neoplasm of the mandible and maxilla, accounting for some 66 reported cases. The case of a 68-year-old man who presented a fistula with orosinus communication of 14-year duration that, after anti-aggregant therapy, began bleeding is reported. The initial microscopic evaluation of the biopsy and radiographic findings were consistent with benign peripheral ameloblastoma without cellular atypia and extensive fields of acantomatous pattern, but immunohistochemical investigation found strong positivity for Bcl-2, cytokeratins CAM 5 and 6, and for Ki-67/MIB-1, changing our diagnosis. The treatment consisted of left maxillary resection followed by reconstruction. Cellular features of malignancy in the surgical specimen confirmed the diagnosis of ameloblastic carcinoma. This case of an aggressive ameloblastic carcinoma of the maxillary gingiva that presented with an unusual histological pattern illustrates that these tumors can create a diagnostic challenge that may require extensive surgical sampling and/or removal to establish the diagnosis. Immunohistochemically analyzed expression of bcl-2 protein, cytokeratins CAM 5 and 6, and Ki-67/MIB-1 antigen serve to characterize the cyto-differentiation and cellular activity of ameloblastic carcinoma.
Ramesh, Namitha; Palukunnu, Biswas; Ravindran, Nidhi; Nair, Preeti P
Non-extraction treatment has gained popularity for corrections of mild-to-moderate class II malocclusion over the past few decades. The distalization of maxillary molars is of significant value for treatment of cases with minimal arch discrepancy and mild class II molar relation associated with a normal mandibular arch and acceptable profile. This paper describes our experience with a 16-year-old female patient who reported with irregularly placed upper front teeth and unpleasant smile. The patient was diagnosed to have angles class II malocclusion with moderate maxillary anterior crowding, deep bite of 4 mm on a skeletal class II base with an orthognathic maxilla and retrognathic mandible and normal growth pattern. She presented an ideal profile and so molar distalization was planned with the first-class appliance. Molars were distalised by 8 mm on the right and left quadrants and class I molar relation achieved within 4 months. The space gained was utilised effectively to align the arch and establish a class I molar and canine relation. PMID:24577171
Altuna, G; Walker, D A; Freeman, E
A recent study has shown that the maxilla in primates can be successfully lengthened (0.5 mm every other day up to 6.0 mm) by means of surgically assisted-rapid orthopedic movement, using the principles of distraction osteogenesis. The present study was designed to determine if the maxilla can be advanced at a faster rate and if relapse would occur after removal of the orthodontic appliance. Metallic markers were placed in the cranial base and maxilla of two Cynomolgus primates, and cephalometric radiographs were taken. Bilateral horizontal and interdental osteotomies were created between in the first premolars and the canines, and the anterior segment was completely mobilized. An orthodontic appliance was bonded to the teeth and the screw was closed, compressing the osteotomy site. One week postoperatively the appliance was opened four quarter turns every day until the anterior segment was advanced by 10 mm. Cephalometric radiographs were taken at 6, 8, and 12 weeks postadvancement. At 12 weeks, the orthodontic appliance was removed, and at that time and 2, 4, and 6 weeks later, cephalometric radiographs were taken and study models fabricated. At the end of the postretention period, the animals were sacrificed, and the maxillae were evaluated by light microscopy. Results showed that the maxilla can be successfully advanced at a faster rate and for longer distances, and that the advanced maxilla does not relapse during the 6-week postretention period.
Bousdras, V. A.; Kalavrezos, N.
This case highlights the use of a custom-made distractor (Synthes GmbH, Oberdorf, Switzerland), used to increase bone height prior to rehabilitation with implant placement, in a patient following excision of an ameloblastoma and reconstruction of her mandible with a fibular flap. A 27-year-old patient had her mandible reconstructed following wide resection of an ameloblastoma. Although a 2.0 LOCK reconstruction plate (Synthes GmbH, Oberdorf, Switzerland) was used for fixation of the fibular bone, the vertical deficiency between the reconstructed segment and the occlusal plane made oral rehabilitation impossible. To overcome this, the fibular bone segment was vertically distracted following a latency period of 4 days. Distractor was left in place for 20 weeks for bone consolidation. Following device removal implants were placed. The novelty of this approach included fixation of the lower arm of the distractor on the LOCK plate. The distractor was unidirectional with two arms of different length. The lower arm composed of a 2.0 mini-plate to fit exactly on the 2.0 LOCK plate whereas the upper arm used a standard 1.5 mini-plate. Advantages of this custom-made distractor included: (i) No need for removal of the reconstruction plate, (ii) no need for an extraoral surgical approach, and (iii) no need for additional drilling to fit the lower arm of the distractor. Technical details and limitations are presented. PMID:25593885
Hinderer, U T
The aesthetic surgery of the facial skeletal contour requires either the performance of ostectomies of excessively prominent segments or the augmentation of retruded segments with organic or synthetic material, in order to achieve balanced tridimensional relations of each segment with regard to the total facial unit. Craniomaxillofacial surgeries are necessary in major malformations or in those combined with malocclusion. In the nasal dorsum or tip, the author prefers the use of cartilage, because synthetic materials need adequate soft-tissue bulk for cover to be inserted without tension and absence of passive mobility of the reception site. For malar augmentation, first proposed by the author and independently by Spadafora in 1971, for chin augmentation up to 8 mm, and for augmentation of the mandibular angle, the author prefers silicone implants because they do not change in shape or volume, may be premanufactured or custom-made, have a similar consistency to that of bone, and do not support bacterial growth. On the other hand, autologous bone grafts adapt less to curved bony surfaces, have an erratic rate of resorption, and need an additional surgical step for removal with the corresponding morbidity and scar. Subperiosteal insertion is preferred because it confers greater stability and the cavity is easier to dissect without soft-tissue damage. Although bone erosion may occur, with over 1200 implants clinically no major change in the soft-tissue contour has been observed, nor has the author been consulted for late complication. In the malar region this may be due to the large surface of the implant and absence of muscular pressure. In the chin, an insertion over the site of the dental roots is avoided. For midface augmentation the following implants are used: (1) The premaxillary lower nasal base implant, proposed in 1971, is indicated to correct a concave midfacial profile, frequent in Asian, black, and Mestizo patients from Latin America and in Caucasian
Rodrigues, Pedro F S; Pandeirada, Josefa N S
The present work investigated the effect of a distracting environment in the performance of attentional and working memory (WM) tasks in elderly participants. To this end, forty elderly performed two attentional tasks (simple reaction time and go/no-go tasks), and three WM tasks (arithmetic, memory for digits and sequences of letters and numbers). Each participant performed the tasks in a distracting and a non-distracting environment, with an interval of 14-21 days between sessions. The results revealed better performance in the attentional tasks when these were done in the non-distracting environment, as compared to when they were done in the distracting environment. Specifically, participants provided more accurate responses, fewer false alarms and omissions when responding in the non-distracting environment than when responding in the distracting environment. Participants were also faster at providing correct responses in the go/no-go task when it was performed in the non-distracting environment. As for the memory tasks, the effect of type of environment was significant only in the memory for digits in a forward direction task. Our data suggest the need to consider the potential damaging consequences of distracting environments when the elderly have to perform tasks that demand their attention. Specific examples of such situations are presented in the discussion (e.g., distracting effect of environment on medical and on psychological evaluations).
Copeland, M; Meisner, J
Use of bone from the maxillary antrum to repair defects in the orbital floor was described more than 20 years ago but has not been reported for correction of orbital rim fractures. The method is appealing because the source is contiguous with the recipient site; enhanced exposure might allow better fracture reduction and evacuation of debris and hematoma from the maxillary sinus. The intraoral approach also avoids an external incision and scar, prevents such complications as pneumothorax or dural perforation, and reduces postoperative pain. In 60 cases of orbital and zygomatic complex fractures seen between 1985 and 1990, less than 8% required more extensive graft material than the maxillary antra could provide. To assess the potential advantages of local over extraanatomical bone grafts, we evaluated maxillary antral bone grafts obtained through buccal sulcus incisions in 14 patients for restoration following fractures of the orbit. Several of these patients are described. Bone union was complete in all patients and there was no morbidity related to infection, oroantral fistula formation, dehiscence, or disfigurement. Sufficient bone was available from the uninvolved contralateral side to repair even severely comminuted fractures. In zygomatic complex fractures, maxillary antral grafts appeared to provide additional strength in the region of the fractured maxillary buttress. The success of the procedure in our experience, coupled with the safety of bone harvesting from this source, and the avoidance of an external scar make maxillary antral bone well suited to reconstruction of all areas of the orbit.
Cuenen, Ariane; Jongen, Ellen M M; Brijs, Tom; Brijs, Kris; Lutin, Mark; Van Vlierden, Karin; Wets, Geert
With age, a decline in attention capacity may occur and this may impact driving performance especially while distracted. Although the effect of distraction on driving performance of older drivers has been investigated, the moderating effect of attention capacity on driving performance during distraction has not been investigated yet. Therefore, the aim was to investigate whether attention capacity has a moderating effect on older drivers' driving performance during visual distraction (experiment 1) and cognitive distraction (experiment 2). In a fixed-based driving simulator, older drivers completed a driving task without and with visual distraction (experiment 1, N=17, mean age 78 years) or cognitive distraction (experiment 2, N=35, mean age 76 years). Several specific driving measures of varying complexity (i.e., speed, lane keeping, following distance, braking behavior, and crashes) were investigated. In addition to these objective driving measures, subjective measures of workload and driving performance were also included. In experiment 1, crash occurrence increased with visual distraction and was negatively related to attention capacity. In experiment 2, complete stops at stop signs decreased, initiation of braking at pedestrian crossings was later, and crash occurrence increased with cognitive distraction. Interestingly, for a measure of lane keeping (i.e., standard deviation of lateral lane position (SDLP)), effects of both types of distraction were moderated by attention capacity. Despite the decrease of driving performance with distraction, participants estimated their driving performance during distraction as good. These results imply that attention capacity is important for driving. Driver assessment and training programs might therefore focus on attention capacity. Nonetheless, it is crucial to eliminate driver distraction as much as possible given the deterioration of performance on several driving measures in those with low and high attention capacity.
Kahraman, O E; Erdogan, Ö; Namli, H; Sencar, L
Our aim was to evaluate the effect of local simvastatin on the formation of new bone using a new design of periosteal distractor. The distractors were placed between the periosteum and bone at the inferior border of the mandible of 20 New Zealand rabbits. In the first group (n=10) simvastatin was applied locally to the distraction zone. The other 10 rabbits served as controls. The formation of new bone was evaluated with digital direct radiography, computed tomography (CT), and histomorphometric analyses. New bone formed in all rabbits, but more formed in the experimental group according to histomorphometric variables. However, other measurements did not differ significantly between the groups. The new design of the periosteal distraction device was successful in causing new bone to form. Local simvastatin made no significant contribution to the procedure.
Kawoosa, A. A.; Mir, M. R.; Butt, M. F.
Ulnar lengthening is an accepted modality of treatment to achieve joint levelling in Kienbock’s disease. The conventional method of ulnar lengthening with a plate and bone graft is fraught with complications including graft site morbidity, non-union, hardware removal and difficulty in the achievement of a proper length. We used a Umex distractor to achieve distraction osteogenesis in a group of 12 patients and assessed them over an average follow-up period of 29.5 months. We had one excellent, ten good and one fair result. We conclude that distraction osteogenesis addresses all the complications of coventional lengthening in addition to providing an increase in the local blood supply, which might be beneficial in a disease that is primarily an avascular necrosis. This procedure addresses both the biomechanical and the biological aspects of this disease. PMID:16821009
Mishra, Jyoti; de Villers-Sidani, Etienne; Merzenich, Michael; Gazzaley, Adam
Aging is associated with deficits in the ability to ignore distractions, which has not yet been remediated by any neurotherapeutic approach. Here, in parallel auditory experiments with older rats and humans, we evaluated a targeted cognitive training approach that adaptively manipulated distractor challenge. Training resulted in enhanced discrimination abilities in the setting of irrelevant information in both species that was driven by selectively diminished distraction-related errors. Neural responses to distractors in auditory cortex were selectively reduced in both species, mimicking the behavioral effects. Sensory receptive fields in trained rats exhibited improved spectral and spatial selectivity. Frontal theta measures of top-down engagement with distractors were selectively restrained in trained humans. Finally, training gains generalized to group and individual level benefits in aspects of working memory and sustained attention. Thus, we demonstrate converging cross-species evidence for training-induced selective plasticity of distractor processing at multiple neural scales, benefitting distractor suppression and cognitive control.
Wais, Peter E; Gazzaley, Adam
Recent research has revealed that the presence of irrelevant visual information during retrieval of long-term memories diminishes recollection of task-relevant visual details. Here, we explored the impact of irrelevant auditory information on remembering task-relevant visual details by probing recall of the same previously viewed images while participants were in complete silence, exposed to white noise, or exposed to ambient sounds recorded at a busy café. The presence of auditory distraction diminished objective recollection of goal-relevant details, relative to the silence and white noise conditions. Critically, a comparison with results from a previous study using visual distractors showed equivalent effects for auditory and visual distraction. These findings suggest that disruption of recollection by external stimuli is a domain-general phenomenon produced by interference between resource-limited, top-down mechanisms that guide the selection of mnemonic details and control processes that mediate our interactions with external distractors.
Zapata, Uriel; Elsalanty, Mohammed E.; Dechow, Paul C.
Mandibular bone transport (MBT) distraction osteogenesis devices are used for achieving reconstruction of mandibular defects in a predictable way, with few complications, less complexity than other alternative surgical procedures, and minimal tissue morbidity. However, selection of appropriate MBT device characteristics is critical for ensuring both their mechanical soundness and their optimal distraction function for each patient's condition. This article assesses six characteristics of currently available MBT devices to characterize their design and function and to classify them in a way that assists the selection of the best device option for each clinical case. In addition, the present work provides a framework for both the biomechanical conception of new devices and the modification of existing ones. PMID:19958167
Nguyen, Tung; Cevidanes, Lucia; Cornelis, Marie A.; Heymann, Gavin; de Paula, Leonardo K.; De Clerck, Hugo
Introduction Bone-anchored maxillary protraction has been shown to be an effective treatment modality for the correction of Class III malocclusions. The purpose of this study was to evaluate 3-dimensional changes in the maxilla, the surrounding hard and soft tissues, and the circummaxillary sutures after bone-anchored maxillary protraction treatment. Methods Twenty-five consecutive skeletal Class III patients between the ages of 9 and 13 years (mean, 11.10 ± 1.1 years) were treated with Class III intermaxillary elastics and bilateral miniplates (2 in the infrazygomatic crests of the maxilla and 2 in the anterior mandible). Cone-beam computed tomographs were taken before initial loading and 1 year out. Three-dimensional models were generated from the tomographs, registered on the anterior cranial base, superimposed, and analyzed by using color maps. Results The maxilla showed a mean forward displacement of 3.7 mm, and the zygomas and the maxillary incisors came forward 3.7 and 4.3 mm, respectively. Conclusions This treatment approach produced significant orthopedic changes in the maxilla and the zygomas in growing Class III patients. PMID:22133943
Catherine Chase, J.D.
Distracted driving has burgeoned with the proliferation of cell phones, global positioning systems and other in-vehicle and personal electronic devices. Annually more than 3,300 people are killed and an additional 400,000 are injured in the United States in distracted driving crashes. The United States (U.S.) federal and state governments have responded to this public health problem with policies and laws; however, a more comprehensive and more effective approach is still needed. Some restrictions on the use of electronic devices while driving by federal employees and some voluntary guidelines and recommendations have been issued. Public opinion polls show support for addressing the issue of distracted driving with state laws. The majority of states have laws banning text messaging while driving and prohibiting the use of an electronic device by teenage or novice drivers. Some states prohibit all drivers from using a hand-held cellphone. Currently no state has a total ban on the use of personal electronic devices while driving. Successful past traffic safety campaigns changing driver behavior have demonstrated the necessity to adopt a “three Es” approach of Enactment of a law, Education of the public about the law, and rigorous Enforcement of the law. Experience reveals that this approach, along with future federal regulation of in-vehicle electronic devices and the employment of technology to limit the use of electronic devices while driving, is needed to alter personal behavior in order to reduce distractions and keep drivers focused on the driving task. PMID:24776229
Conley, Richard; Legan, Harry
Treatment planning decisions in the transverse dimension have historically been based on the presenting mandibular arch width and form. Distraction osteogenesis (DO), originally developed by Russian orthopedic surgeon Ilizarov, has produced significant results in limb lengthening. Mandibular symphyseal DO was introduced by Guerrero, providing a new paradigm for patients whose treatment alternatives and results were previously limited. Orthodontic and surgical techniques and principles will be shown using completed and current cases.
Green, Stuart A; Horton, Eric; Baker, Michael; Utkan, Ali; Caiozzo, Vincent
To better study the effects of limb lengthening on skeletal muscle, the authors developed a rat model that uses a miniature external skeletal fixator applied to the tibia of an adult Sprague-Dawley rat. The mounting and lengthening protocols follow the principles developed by Ilizarov. With the initial version of the fixator, the rats had progressive equinus contractures develop because the calf muscles resisted elongation. By incorporating a footplate in the distraction apparatus, tibial lengthening can be achieved without concomitant equinus.
Background The feasibility of distal femur epiphysis preservation through epiphyseal distraction by external fixator in childhood osteosarcoma was explored. Methods Between July 2007 and May 2011, 10 children who were suffering from distal femur osteosarcoma received epiphyseal distraction by external fixator, combined with tumor resection and repair with massive allograft bone to preserve the epiphysis of the distal femur and knee function. There were six male and four female patients, 9- to 14-years old (average 10.5 years old). The tumors were staged clinically according to the Enneking staging method: six cases were classified as stage in IIA and four cases as stage in IIB. All patients were diagnosed by biopsy, then received chemotherapy before and after surgery. All patients received tumor bone resection and the defects of the bone were repaired with massive allograft bone that was fixed by intramedullary nails; the distracted epiphysis and allograft bone were fixed with cancellous screws. Results All cases received follow-up from 15 to 56 months (average 38.5 months). There were no local recurrences. One case died of lung metastasis and one case had poor incision healing for rejection of allograft bone. According to the functional evaluation criteria of the International Society of Limb Salvage (ISOLS) after operation, five cases were rated excellent, four cases good and one case fair. The ratio of excellent or good was 90.0%. There was no statistically significant difference in length between the operated and the normal lower limbs during the last review. Conclusions Epiphyseal distraction by external fixator can result in satisfactory limb length and joint function for children with a malignant bone tumor. PMID:25099460
Pirner, S; Tingelhoff, K; Wagner, I; Westphal, R; Rilk, M; Wahl, F M; Bootz, F; Eichhorn, Klaus W G
Manual segmentation of computed tomography (CT) datasets was performed for robot-assisted endoscope movement during functional endoscopic sinus surgery (FESS). Segmented 3D models are needed for the robots' workspace definition. A total of 50 preselected CT datasets were each segmented in 150-200 coronal slices with 24 landmarks being set. Three different colors for segmentation represent diverse risk areas. Extension and volumetric measurements were performed. Three-dimensional reconstruction was generated after segmentation. Manual segmentation took 8-10 h for each CT dataset. The mean volumes were: right maxillary sinus 17.4 cm(3), left side 17.9 cm(3), right frontal sinus 4.2 cm(3), left side 4.0 cm(3), total frontal sinuses 7.9 cm(3), sphenoid sinus right side 5.3 cm(3), left side 5.5 cm(3), total sphenoid sinus volume 11.2 cm(3). Our manually segmented 3D-models present the patient's individual anatomy with a special focus on structures in danger according to the diverse colored risk areas. For safe robot assistance, the high-accuracy models represent an average of the population for anatomical variations, extension and volumetric measurements. They can be used as a database for automatic model-based segmentation. None of the segmentation methods so far described provide risk segmentation. The robot's maximum distance to the segmented border can be adjusted according to the differently colored areas.
Rohilla, Ajit Kumar; Choudhary, Shweta; Kaur, Ravneet
ABSTRACT Traumatic injuries to primary dentition may interfere with the development of permanent dentition. Among the many malformations, dilaceration is particularly important to the clinician. Management of dilacerated maxillary central incisor requires a multidisciplinary approach. The main purpose of this review is to present the etiological factors, the mechanism, clinical features, radiographic features and treatment of dilaceration of the maxillary central incisors. How to cite this article: Walia PS, Rohilla AK, Choudhary S, Kaur R. Review of Dilaceration of Maxillary Central Incisor: A Multidisciplinary Challenge. Int J Clin Pediatr Dent 2016;9(1):90-98. PMID:27274164
Brunner, U; Kessler, S; Cordey, J; Rahn, B; Schweiberer, L; Perren, S M
For large shaft defects of tibia and femur, distraction-compression osteosynthesis (Ilizarov) provides an ideal autologous bone graft. Combination of this with an intramedullary interlocking nail instead of an external fixator could improve patient comfort, because transport with a small external device takes only one-third of the total fixation period. Using 21 adult female sheep we created standardized tibia shaft defects 20 mm (medium size) and 45 mm (large size) in length. The tibiae were stabilized with non-reamed intramedullary interlocking nails. Following corticotomy by chisel, segments were transported using subcutaneous traction wires with a screw as a fulcrum to maintain stationary skin exit points without soft tissue problems. The external traction devices were removed after 12 or 16 weeks. Animals were sacrificed after 12 or 24 weeks with medium-size defects, and after 16 or 32 weeks with large defects. We evaluated the results clinically, by standardized weekly X-rays and, after sacrifice, by quantitative computed tomography (QCT). No animals had to be excluded from the study. Despite primary destruction of the intramedullary circulation all distraction gaps were spanned with bone. X-Rays showed typical signs of good quality of distraction bone regeneration (narrow radiolucent zone in the middle of the regenerate, longitudinal structure), continuous calcification, and cortex formation. QCT cross sections showed completely circular bone regeneration with small and large defects. Bone regeneration was faster on the dorsal side, where more bone was formed than ventrally. Small defects can remain ventrally in the regenerate; these close secondarily.(ABSTRACT TRUNCATED AT 250 WORDS)
Slotboom, Jantine; Hoppenbrouwers, Sylco S; Bouman, Yvonne H A; In 't Hout, Willem; Sergiou, Carmen; van der Stigchel, Stefan; Theeuwes, Jan
Impairments in executive functioning give rise to reduced control of behavior and impulses, and are therefore a risk factor for violence and criminal behavior. However, the contribution of specific underlying processes remains unclear. A crucial element of executive functioning, and essential for cognitive control and goal-directed behavior, is visual attention. To further elucidate the importance of attentional functioning in the general offender population, we employed an attentional capture task to measure visual attention. We expected offenders to have impaired visual attention, as revealed by increased attentional capture, compared to healthy controls. When comparing the performance of 62 offenders to 69 healthy community controls, we found our hypothesis to be partly confirmed. Offenders were more accurate overall, more accurate in the absence of distracting information, suggesting superior attention. In the presence of distracting information offenders were significantly less accurate compared to when no distracting information was present. Together, these findings indicate that violent offenders may have superior attention, yet worse control over attention. As such, violent offenders may have trouble adjusting to unexpected, irrelevant stimuli, which may relate to failures in self-regulation and inhibitory control.
Caiozzo, Vincent J; Utkan, Ali; Chou, Richard; Khalafi, Afshin; Chandra, Heena; Baker, Michael; Rourke, Bryan; Adams, Greg; Baldwin, Ken; Green, Stuart
Although a great deal of interest has been given to understanding the mechanisms involved in regulating the radial growth that occurs because of resistance training, much less has been given to studying the longitudinal growth of skeletal muscle that occurs because of passive stretch. The current authors provide a brief overview of key issues relevant to the longitudinal growth of skeletal muscle that occurs during distraction osteogenesis. Specifically, five key issues are addressed: (1) the pattern of sarcomerogenesis during distraction; (2) sarcomerogenesis and altered expression of sarcomeric and nonsarcomeric genes; (3) the satellite cell hypothesis; (4) mitogenic factors; and (5) new approaches for studying the longitudinal growth of skeletal muscle. A discussion is provided that revolves around the concept of a negative feedback loop. One of the most interesting issues to be resolved in muscle biology is the role of satellite cells in regulating the growth of skeletal muscle. Currently, it is not known whether satellite cell activation is a prerequisite for the longitudinal growth of skeletal muscle. Gene chip analyses provide a paradoxical view, showing that distraction osteogenesis results in the upregulation of a gene, GADD45, involved with growth arrest and deoxyribonucleic acid destruction.
Alonso, N; Munhoz, A M; Fogaça, W; Ferreira, M C
Craniofaciostenosis is often associated with midfacial hypoplasia and has been treated traditionally using Le Fort advancement osteotomies and bone grafts. The surgical procedure requires a prolonged operating time, several osteotomies with a significant blood loss, and wide surgical exposure. According to the principles of bone lengthening, we performed midfacial advancement by bone distraction in 4 patients with midfacial hypoplasia to reduce the operative time and complication rate. In 2 patients with Crouzon's syndrome we performed a Le Fort III osteotomy and placed the distraction device behind the malar eminence and screwed it on the temporal bone bilaterally. In the other 2 children, with Apert's syndrome, we performed frontal advancement and remodeling before placing the device during the same surgery behind the malar bone without any midfacial osteotomy. It appears to us that patients with more severe deformities will need surgical procedures to offer more satisfactory results. In these patients, distraction is an initial therapy to reduce the severity of the deformity, making it possible to effect a better treatment afterward.
Puschmann, Sebastian; Sandmann, Pascale; Bendixen, Alexandra; Thiel, Christiane M
Recent electrophysiological studies have provided evidence that changes in multisensory processing in auditory cortex cannot only be observed following extensive hearing loss, but also in moderately hearing-impaired subjects. How the reduced auditory input affects audio-visual interactions is however largely unknown. Here we used a cross-modal distraction paradigm to investigate multisensory processing in elderly participants with an age-related high-frequency hearing loss as compared to young and elderly subjects with normal hearing. During the experiment, participants were simultaneously presented with independent streams of auditory and visual input and were asked to categorize either the auditory or visual information while ignoring the other modality. Unisensory sequences without any cross-modal input served as control conditions to assure that all participants were able to perform the task. While all groups performed similarly in these unisensory conditions, hearing-impaired participants showed significantly increased error rates when confronted with distracting cross-modal stimulation. This effect could be observed in both the auditory and the visual task. Supporting these findings, an additional regression analysis indicted that the degree of high-frequency hearing loss significantly modulates cross-modal visual distractibility in the auditory task. These findings provide new evidence that already a moderate sub-clinical hearing loss, a common phenomenon in the elderly population, affects the processing of audio-visual information.
Dimitrova, Marina; Stobbe, Nina; Schaefer, H. Martin; Merilaita, Sami
High-contrast markings, called distractive or dazzle markings, have been suggested to draw and hold the attention of a viewer, thus hindering detection or recognition of revealing prey characteristics, such as the body outline. We tested this hypothesis in a predation experiment with blue tits (Cyanistes caeruleus) and artificial prey. We also tested whether this idea can be extrapolated to the background appearance and whether high-contrast markings in the background would improve prey concealment. We compared search times for a high-contrast range prey (HC-P) and a low-contrast range prey (LC-P) in a high-contrast range background (HC-B) and a low-contrast range background (LC-B). The HC-P was more difficult to detect in both backgrounds, although it did not match the LC-B. Also, both prey types were more difficult to find in the HC-B than in the LC-B, in spite of the mismatch of the LC-P. In addition, the HC-P was more difficult to detect, in both backgrounds, when compared with a generalist prey, not mismatching either background. Thus, we conclude that distractive prey pattern markings and selection of microhabitats with distractive features may provide an effective way to improve camouflage. Importantly, high-contrast markings, both as part of the prey coloration and in the background, can indeed increase prey concealment. PMID:19324754
Schmid-Leuz, Barbara; Elsesser, Karin; Lohrmann, Thomas; Jöhren, Peter; Sartory, Gudrun
A survey of the discrepant findings regarding the effects of attention focusing and distraction on exposure suggested that subjective measures of anxiety and avoidance respond better to the latter condition, and heart rate (HR) reaction responds to the former. To test this hypothesis, 63 dental phobics were recruited who had not visited a dentist for a mean of 6.6 (1.5-25) years. Participants received a 1-h exposure session with either attention focusing or distraction. Subjective anxiety and HR to phobia-related pictures were assessed before and after the treatment session and again after 1 week. Avoidance was recorded in terms of adherence to the dental treatment schedule in the following 6 months. Contrary to expectation, state anxiety showed a greater decrease in the attention focusing than the distraction condition after 1 week. Both treatment conditions were similarly effective with regard to HR and avoidance. HR habituated in both groups after exposure and 73% of followed-up patients adhered to the dental treatment schedule. Comparison of the present with previous results suggests that the differences between attentional conditions tend to be more pronounced during shorter exposure sessions than were employed in the present study.
Matusz, Pawel J; Broadbent, Hannah; Ferrari, Jessica; Forrest, Benjamin; Merkley, Rebecca; Scerif, Gaia
How does the multi-sensory nature of stimuli influence information processing? Cognitive systems with limited selective attention can elucidate these processes. Six-year-olds, 11-year-olds and 20-year-olds engaged in a visual search task that required them to detect a pre-defined coloured shape under conditions of low or high visual perceptual load. On each trial, a peripheral distractor that could be either compatible or incompatible with the current target colour was presented either visually, auditorily or audiovisually. Unlike unimodal distractors, audiovisual distractors elicited reliable compatibility effects across the two levels of load in adults and in the older children, but high visual load significantly reduced distraction for all children, especially the youngest participants. This study provides the first demonstration that multi-sensory distraction has powerful effects on selective attention: Adults and older children alike allocate attention to potentially relevant information across multiple senses. However, poorer attentional resources can, paradoxically, shield the youngest children from the deleterious effects of multi-sensory distraction. Furthermore, we highlight how developmental research can enrich the understanding of distinct mechanisms controlling adult selective attention in multi-sensory environments.
Al-Ghamdi, Nuha S.; Al-Nazhan, Saad
An immature maxillary first premolar in an 8-year-old female was treated using a regenerative approach. The root canal was gently irrigated with 5.25% sodium hypochlorite without instrumentation under aseptic conditions and then medicated with calcium hydroxide (Ca[OH]2) for 3 weeks. The Ca(OH)2 was removed, and bleeding was initiated mechanically using a hand file to form an intracanal blood clot. Mineral trioxide aggregate was placed over the blood clot, and the access cavity was sealed with a double filling. Increases in root length and width were radiographically evident, at the 6-month follow-up exam. The case was followed for 3 years. The development of 3 roots with complete apical closure was confirmed using cone beam computed tomography. PMID:26752847
Al-Ghamdi, Nuha S; Al-Nazhan, Saad
An immature maxillary first premolar in an 8-year-old female was treated using a regenerative approach. The root canal was gently irrigated with 5.25% sodium hypochlorite without instrumentation under aseptic conditions and then medicated with calcium hydroxide (Ca[OH]2) for 3 weeks. The Ca(OH)2 was removed, and bleeding was initiated mechanically using a hand file to form an intracanal blood clot. Mineral trioxide aggregate was placed over the blood clot, and the access cavity was sealed with a double filling. Increases in root length and width were radiographically evident, at the 6-month follow-up exam. The case was followed for 3 years. The development of 3 roots with complete apical closure was confirmed using cone beam computed tomography.
Carvalho Visioli, Adriano Rossini; de Oliveira e Silva, Cléverson; Marson, Fabiano Carlos; Takeshita, Wilton Mitsunari
In this manuscript, we present a rare case report of giant complex odontoma in the maxillary sinus, where the applied therapy included complete excision of the lesion with a conservative approach. Odontomas are also called benign growth abnormalities or hamartomas. They represent a more common type of odontogenic tumor and are related to various disorders such as bad dental placements, expansion, increased volumetric bone, and no eruption of permanent teeth. Usually they have an asymptomatic evolutionary course. The etiologic factors, although obscure, are related to local trauma, infection, and genetic factor. The structural composition of an odontoma consists of mature dental tissues. Odontomas can be differentiated according to their anatomical presentations: Compound odontoma-clusters of several denticles and complex odontoma-well defined tumefaction mass. The diagnosis can be performed by radiographic examination. PMID:26389051
Kretschmer, W B; Zoder, W; Baciut, G; Bacuit, Mihaela; Wangerin, K
The aim of the study was to investigate the accuracy of a modified pin system for the vertical control of maxillary repositioning in bimaxillary osteotomies. The preoperative cephalograms of 239 consecutive patients who were to have bimaxillary osteotomies were superimposed on the postoperative films. Planned and observed vertical and horizontal movements of the upper incisor were analysed statistically. The mean deviations of -0.07 mm (95% confidence intervals (CIs) -0.17 to 0.04 mm) for the vertical movement and 0.12 mm (95% CI -0.06 to 0.30 mm) for the horizontal movement did not differ significantly from zero. Comparison of the two variances between intrusion and extrusion of the maxilla did not differ significantly either (p=0.51). These results suggest that the modified pin system for vertical control combined with interocclusal splints provides accurate vertical positioning of the anterior maxilla in orthognathic surgery.
KOMURO, Yuzo; SHIMIZU, Azusa; SHIMOJI, Kazuaki; MIYAJIMA, Masakazu; ARAI, Hajime
Twenty years have passed since distraction osteogenesis was introduced into the field of craniomaxillofacial surgery, with distraction osteogenesis gradually consolidating its position for midface advancement in syndromic craniosynostosis. On the other hand, no consensus has been reached regarding its adaptation to calvarial bone. We reported that distraction osteogenesis was useful in posterior cranial vault expansion, and subsequently, similar reports have been successively observed worldwide. In posterior cranial vault distraction, intracranial capacity could be greatly expanded due to its simultaneous expansion with the scalp, with little risk of relapse because new bone is regenerated in the distraction gap. The possibility was suggested that the standard of first carrying out fronto-orbital advancement (FOA) for brachycephaly observed in syndromic craniosynostosis will greatly change posterior cranial vault distraction. PMID:26226978
Broos, Hans J. H. P.; Witjes, J. Alfred; Hendrikx, Ad. J. M.; Scherpbier, Albert J. J. M.
Background Professionals working in the operating room (OR) are subject to various distractions that can be detrimental to their task performance and the quality of their work. This study aimed to quantify the frequency, nature, and effect on performance of (potentially) distracting events occurring during endourological procedures and additionally explored urologists’ and residents’ perspectives on experienced ill effects due to distracting factors. Methods First, observational data were collected prospectively during endourological procedures in one OR of a teaching hospital. A seven-point ordinal scale was used to measure the level of observed interference with the main task of the surgical team. Second, semistructured interviews were conducted with eight urologists and seven urology residents in two hospitals to obtain their perspectives on the impact of distracting factors. Results Seventy-eight procedures were observed. A median of 20 distracting events occurred per procedure, which corresponds to an overall rate of one distracting event every 1.8 min. Equipment problems and procedure-related and medically irrelevant communication were the most frequently observed causes of interruptions and identified as the most distracting factors in the interviews. Occurrence of distracting factors in difficult situations requiring high levels of concentration was perceived by all interviewees as disturbing and negatively impacting performance. The majority of interviewees (13/15) thought distracting factors impacted more strongly on residents’ compared to urologists’ performance due to their different levels of experience. Conclusion Distracting events occur frequently in the OR. Equipment problems and communication, the latter both procedure-related and medically irrelevant, have the largest impact on the sterile team and regularly interrupt procedures. Distracting stimuli can influence performance negatively and should therefore be minimized. Further research
Malagon, Hector Hidalgo; Romo, Gabriela Wong; Quintero Mosqueda, Francisco Rafael; Magaña, Fernando Gonzalez
Osteogenesis distraction is an increasingly used technique for the correction of facial deformities because it offers a faster and more controlled growth of the hypoplasic bone along with the elongation of the soft tissues. In this article, we describe the technique and our experience in midface distraction using an external multivectoral distraction device (BLUE Device; W. Lorenz, Jacksonville, FL) and custom-made midface osteotomies for the correction of severe hypoplasia.
Macy, Michelle L.; Carter, Patrick M.; Bingham, C. Raymond; Cunningham, Rebecca M.; Freed, Gary L.
Objective Driver distraction has been identified as a threat to individual drivers and public health. Motor vehicle collisions remain a leading cause of death for children yet little is known about distractions among drivers of children. This study sought to characterize potential distractions among drivers of children. Methods A two-site, cross-sectional, computerized survey of child passenger safety practices was conducted among adult drivers of 1- to 12-year-old children who presented for emergency care between October 2011-May 2012. Drivers indicated the frequency with which they engaged in ten potential distractions in the past month while driving with their child. Distractions were grouped in four categories: 1) non-driving, 2) cellular phone, 3) child, 4) directions. Information about other unsafe driving behaviors and sociodemographic characteristics was collected. Results Nearly 90% of eligible parents participated. Analysis included 570 (92.2%) drivers. Non-driving and cellular phone-related distractions were disclosed by >75% of participants. Fewer participants disclosed child (71.2%) and directions-related distractions (51.9%). Child age was associated with each distraction category. Cellular phone-related distractions were associated with the child riding daily in the family car, non-Hispanic white and other race/ethnicity, and higher education. Parents admitting to drowsy driving and being pulled over for speeding had over two-times higher odds of disclosing distractions from each category. Conclusions Distracted driving activities are common among drivers of child passengers and associated with other unsafe driving behaviors. Child passenger safety may be improved by preventing crash events through the reduction or elimination of distractions among drivers of child passengers. PMID:24767781
Ramachamparambathu, Ashir Kolikkal; Vengal, Manoj; Siyo, Nizaro; Ahmed, Anis
Malignant tumours of maxillary sinus are rare. They are usually diagnosed in the late stages when they perforate the sinus walls. The presence of large air space in the maxillary sinus facilitates asymptomatic growth of the sinus malignancy. The clinical presentation of these tumours depends on the sinus wall involved by the disease. The medial wall is usually the first to become eroded, leading to nasal obstruction, epistaxis or discharge. Rarely, symptoms of maxillary sinus carcinoma can resemble dental infection and the affected patients may visit dental clinic seeking treatment. This report presents a case of carcinoma of maxillary sinus mimicking odontogenic infection. Computed tomographic findings explained the reason for the present lesion to masquerade as an inflammatory condition. The importance of advanced imaging modalities for prompt identification of such lesions is discussed. PMID:27790593
Rockhill, R C; Klein, M D
Paecilomyces lilacinus was isolated on two separate occasions from the left antrum of a patient with chronic maxillary sinusitis. The clinical presentation and characteristics of the fungus and the sinus debris histopathology are discussed. Images PMID:7430339
Eguchi, Yoshitaka; Wakitani, Shigeyuki; Naka, Yoshifumi; Nakamura, Hiroaki; Takaoka, Kunio
To investigate new methods that can decrease the duration of bone transport (BT) distraction osteogenesis, we injected composite materials containing recombinant human bone morphogenetic protein-2 (BMP-2) and induced the generation of a callus bridge by rapid segmental transport (4 mm/day) in a rabbit bone defect model. The composite materials consisted of BMP-2 (0, 30, or 100 µg), β-tricalcium phosphate powder (βTCP, 100 mg/animal; particle size, <100 µm), and polyethylene glycol (PEG; 40 mg/animal). A paste of equivalent composition was percutaneously injected at the lengthening and the docking sites after surgery and after BT, respectively. The radiographic, mechanical, and histological examinations 12 weeks post-operative revealed that the generation of bridging callus in the presence and in the absence of BMP-2 was significantly different. The callus mass in the bone defect region was adequately and consistently developed in the presence of 100 µg of BMP (administered for 6 weeks), and the bones were consolidated in 12 weeks. Such an adequate callus formation was not observed in the control animals without BMP-2 treatment. The result of this experimental study suggests the potential application of BMP-2 in accelerating callus formation and in enabling rapid bone transporting, thereby shortening the treatment period for the repair of diaphyseal bone defects by distraction osteogenesis.
Boccaccio, A; Pappalettere, C; Kelly, D J
Mandibular distraction osteogenesis is a clinical procedure used for modifying the mandibular geometry when problems of dental overcrowding and arch shrinkage occur. The objective of this study is to use a computational model of tissue differentiation to examine the influence of the rate of distraction on bone re-growth within the fracture callus of a human mandible submitted to symphyseal distraction osteogenesis. A 3D model of the mandible is reconstructed from CT scan data and meshed into finite elements. Two different mastication loadings have been investigated: a 'full' mastication load and a 'reduced' mastication load where the action of each muscle was reduced by 70%. Four different distraction rates were analyzed: 0.6, 1.2, 2, and 3 mm/day, allowing a total displacement of 6 mm. In the early stages of the distraction process it is predicted that there is a decrease in the amount of bone tissue forming within the center of the fracture gap for all distraction rates. After the initial phases of expansion, the bone tissue within the callus increases for the slower rate of distraction or continues to decrease at the faster rates of distraction. At the end of the simulated maturation period, 47% of the distracted callus was predicted to consist of bone tissue for a distraction rate of 0.6 mm/day, decreasing to 22% for a distraction rate of 3 mm/day. Significantly higher amounts of bone formation were predicted for all distraction rates for the case of reduced mastication loading. Disparities between the model predictions and what is observed in vivo were found. For instance, during the latency period, the distraction period and beyond, the model is predicting larger than expected amounts of cartilage tissue formation within the callus. This and other limitations of the proposed model are discussed and possible specific explanations for these disparities are provided in the paper. The model predicts a distraction rate of around 1.2 mm/day to be optimal as higher
Paccione, M F; Mehrara, B J; Warren, S M; Greenwald, J A; Spector, J A; Luchs, J S; Longaker, M T
Distraction osteogenesis is a well-established technique of endogenous tissue engineering. The biomechanical factors thought to affect the quality of the distraction regenerate include the latency, rate, rhythm, and consolidation period. In an effort to understand the impact of these parameters on regenerate bone formation, this study was designed to decipher the most adaptive response in a rat model of mandibular distraction osteogenesis. Ninety-six adult Sprague-Dawley rats were divided into 16 subgroups (n = 6 per subgroup) based on variations in the distraction parameters (i.e., latency, rate, and rhythm). After a 28-day consolidation period, the mandibles were harvested, decalcified, and sectioned. A standardized histologic ranking system was used to evaluate the effect of each protocol on the adaptive response of the regenerate bone. In this study, we have demonstrated that the latency period dramatically affects the success of distraction osteogenesis. Furthermore, distraction rates up to 0.50 mm per day stimulated excellent regenerate bone formation, whereas greater distraction rates produced a fibrous union. Finally, higher frequency distraction (i.e., increased rhythm) appeared to accelerate regenerate bone formation. We believe that defining the critical parameters of this model will improve future analysis of gene expression during rat mandibular distraction osteogenesis and may facilitate the development of biologically based strategies designed to enhance regenerate bone formation.
Havlik, R J; Bartlett, S P
Distraction lengthening is a technique that was initially developed for correction of lower limb length discrepancies. It has recently been adapted to maxillofacial problems and has gained increasing popularity in this application. This report illustrates the principles involved in mandibular distraction lengthening and offers possible solutions to potentially limiting clinical problems. First, conventional technique dictates that a distinct periosteal sleeve is necessary for distraction osteogenesis to occur. However, in this case, distraction was performed through an area of scar tissue in which the native periosteum was destroyed. The ability to extend the use of the technique of distraction successfully to suboptimal clinical situations may broaden the indications for its use. Second, fixator instability is a potentially common problem in these cases because of the forces involved in distraction osteogenesis and the duration of the process. However, mechanical rigidity is essential consolidation (typically requiring twice as long as the distraction phase). Fixator instability can be successfully salvaged during the mineralization phase of bony healing through the use of an onlay corticocancellous bone "plate," which resorbs as the distraction gap gains strength. This report highlights one of the main advantages of the distraction process: the expansion of the soft-tissue matrix of the face.
Shilo, Dekel; Emodi, Omri; Aizenbud, Dror; Rachmiel, Adi
Background: Obstructive sleep apnea (OSA) in individuals with craniofacial anomalies can compromise airway and is a serious life-threatening condition. In many cases, tracheostomy is carried out as the treatment of choice. Distraction osteogenesis of the mandible as a treatment modality for OSA is very useful and may spare the need for tracheostomy or allow decannulation, yet controlling the vector of distraction is still a major challenge. We present a method for controlling the vector of distraction. Materials and Methods: Eight patients with severe respiratory distress secondary to a micrognathic mandible were treated by mandibular distraction osteogenesis using either external or internal devices. Temporary anchorage devices (TADs) and orthodontic elastics were used to control the vector of distraction. Cephalometric X-rays, computed tomography, and polysomnographic sleep studies were used to analyze the results. Results: A mean distraction of 22 mm using the internal devices and a mean of 30 mm using the external devices were achieved. Increase in the pharyngeal airway and hyoid bone advancement was also observed. Anterior-posterior advancement of the mandible was noted with no clockwise rotation. Most importantly, clinical improvement in symptoms of OSA, respiratory distress, and feeding was noted. Conclusions: We describe a method for controlling the vector of distraction used as a treatment for OSA. In these cases, TADs were used as an anchorage unit to control the vector of distraction. Our results show excellent clinical and radiographical results. TADs are a simple and nonexpensive method to control the vector of distraction.
Wilson, Fernando A; Stimpson, Jim P; Tibbits, Melissa K
Distracted driving is now an increasingly deadly threat to road safety. We provide evidence that intoxicated driving is increasingly responsible for recent increases in fatalities from distracted driving crashes. This study describes trends in deaths on U.S. public roads caused by alcohol-involved and distracted drivers using the Fatality Analysis Reporting System (FARS)-a census of fatal crashes on U.S. public roads. Fatality rates per vehicle-miles traveled are calculated using data from the Federal Highway Administration. Alcohol-involved drivers who are simultaneously distracted were responsible for 1750 deaths in 2009, an increase of more than 63% from 2005 when there were 1072 deaths. Alcohol use while driving is increasingly responsible for a growing number of fatalities from distracted driving, accounting for 32% of deaths from distracted driving in 2009 versus 24% in 2005. The fatality rate from these crashes increased from 35.9 to 59.2 deaths per 100 billion vehicle-miles traveled after 2005. Alcohol use is quickly increasing as an important factor behind distracted driving fatalities. This has implications for policies combating distracted driving that do not address the role of alcohol use in distracted driving.
Shen, Weimin; Tang, Chenlu; Yang, Junyi; Kong, Liangliang
Background: The treatment of patients with partially atrophic rib and rib defects requires an ideal arc of the rib that has adequate bone length and width. To design and assemble a distraction device with a strain gauge, we need to establish an animal model for testing it during rib distraction osteogenesis. Methods: Osteotomies were performed at the same position in the fifth rib in 8 rabbits. Customized distraction devices attached to strain gauges were used to distract the ribs. After a month of distraction and consolidation, loading deflection gauges were used, and specimens were examined histologically to record bone formation. Results: Distraction osteogenesis was carried out successfully in all rabbits when the device used to distract the rib up to 4 cm. Conclusions: The device can be used for strain testing during rib distraction osteogenesis performed in a rabbit model. There was no significant difference in the loading deflection gauges of the bone between osteogenic and contralateral ribs. This animal model of costal distraction osteogenesis is successful. PMID:27826456
Ragunathan, Ramachandran; Ebenezar, A. V. Rajesh; Mohan, Ajit George; Anand, S.
This clinical article describes three different case reports of maxillary and mandibular second molars with the unusual anatomy of single root with a single canal and their endodontic management. An unusual case of bilateralism is observed in the first two cases in the form of single-rooted second mandibular molars in both the quadrant of the same patient. The presence of maxillary second molar with single root and single canal in the third case is unusual. PMID:27829778
Asghari, Vahideh; Rahimi, Saeed; Ghasemi, Negin; Talebzadeh, Bita; Norlouoni, Ahmad
Thorough knowledge of the morphology and internal anatomy of the root canal system is essential, because it determines the successful outcome of endodontic treatment. The main goal of endodontic treatment is to prevent apical periodontitis and/or to promote the healing of periapical lesion. Presence of two canals or roots on the palatal side of the first maxillary molar has rarely been reported. This case report presents a maxillary first molar with two separate palatal roots. PMID:26523146
Leao de Queiroz, Cristhiane; Terada, Andrea Sayuri Silveira Dias; Dezem, Thais Uenoyama; Gomes de Araújo, Lais; Galo, Rodrigo; Oliveira-Santos, Christiano; Alves da Silva, Ricardo Henrique
The purpose of this study was to evaluate dimensions of adult human maxillary sinuses on panoramic radiographs and their possible application on the sex determination for forensic purposes. The sample comprised 64 database panoramic radiographs from individuals aged 20 years or older (32 male and 32 female subjects), with complete permanent dentition (or absence of third molars). One examiner measured the width and height of the right and left maxillary sinuses using the software Image J 1.47v (National Institutes of Health, Bethesda, USA). Measurements were repeated to calculate intra-observer agreement. Chi-Square test, Kappa, ANOVA and T-Student were used for results analysis for p≤ 0.05. Intra-observer agreement with correlation Kappa ranged between 0.38 and 0.96. For female subjects, the mean height and width of the left maxillary sinus were 28.7856mm and 44.6178mm, respectively. And right maxillary sinus was 27.7163mm for height and 45.1850mm for width. Male subjects were found to have the mean height and width of the left maxillary sinus 30.9981mm and 48.7753mm, respectively. And right maxillary sinus was 30.7403mm for height and 48.5753mm for width. There was a statistically significant difference in the height and width of maxillary sinuses between males and females. It can be concluded that maxillary sinuses height and width on panoramic radiographs can be used to determine the gender of adult human subjects.
Koç, Nagihan; Çağırankaya, L. Berna; Akkaya, Nursel
Congenital absence of maxillary permanent canines is an extremely rare condition, which may appear as part of a syndrome or as a nonsyndromic form. Nonsyndromic canine agenesis combined with other types of tooth agenesis has occasionally been described in the literature but isolated cases are rarely observed. This report presents an isolated case of maxillary permanent canine agenesis in a healthy 18-year-old female patient and a literature review on the prevalence, etiology, and differential diagnosis of the condition. PMID:25177502
Leao de Queiroz, Cristhiane; Terada, Andrea Sayuri Silveira Dias; Dezem, Thais Uenoyama; Gomes de Araújo, Lais; Galo, Rodrigo; Oliveira-Santos, Christiano
Absract The purpose of this study was to evaluate dimensions of adult human maxillary sinuses on panoramic radiographs and their possible application on the sex determination for forensic purposes. The sample comprised 64 database panoramic radiographs from individuals aged 20 years or older (32 male and 32 female subjects), with complete permanent dentition (or absence of third molars). One examiner measured the width and height of the right and left maxillary sinuses using the software Image J 1.47v (National Institutes of Health, Bethesda, USA). Measurements were repeated to calculate intra-observer agreement. Chi-Square test, Kappa, ANOVA and T-Student were used for results analysis for p≤ 0.05. Intra-observer agreement with correlation Kappa ranged between 0.38 and 0.96. For female subjects, the mean height and width of the left maxillary sinus were 28.7856mm and 44.6178mm, respectively. And right maxillary sinus was 27.7163mm for height and 45.1850mm for width. Male subjects were found to have the mean height and width of the left maxillary sinus 30.9981mm and 48.7753mm, respectively. And right maxillary sinus was 30.7403mm for height and 48.5753mm for width. There was a statistically significant difference in the height and width of maxillary sinuses between males and females. It can be concluded that maxillary sinuses height and width on panoramic radiographs can be used to determine the gender of adult human subjects. PMID:27847394
Jain, Somya; Patil, Raju Umaji; Asokan, Alexander; Kambalimath, Deepashri
ABSTRACT Congenitally missing teeth (CMT) are among one of the commonly known dental anomalies. The most frequently missing teeth in the permanent dentition, excluding the third molars, are mandibular second premolars and maxillary lateral incisors. Exclusive agenesis of both maxillary canines is an extremely rare occurrence and only a few cases have been reported. Previous studies showed that the prevalence of maxillary canine agenesis varies between 0.07 and 0.13%. In recent studies on Indian population, no cases of maxillary canine agenesis have been documented. This paper reports a case of non-syndromic bilateral agenesis of permanent maxillary canines, along with agenesis of both mandibular central incisors in a healthy 13-year-old Indian female patient; and a brief literature review on prevalence, etiology and treatment modalities of the condition. How to cite this article: Kambalimath HV, Jain S, Patil RU, Asokan A, Kambalimath D. Permanent Maxillary Canine Agenesis: A Rare Case Report. Int J Clin Pediatr Dent 2015; 8(3):242-246. PMID:26604546
Koppe, Thomas; Röhrer-Ertl, Olav; Breier, Silvana; Wallner, Claus-Peter
In a mixed sex sample of ten adult gibbon (Hylobates moloch) skulls, one cranium of a male with maxillary sinus atelectasis of the left side was identified. While external inspection revealed a slight drop of the left orbital floor, serial coronal computer tomography (CT) scans show characteristic changes of the left maxillary sinus and its surrounding structures. In addition to the sunken orbital floor, radiological features of the specimen include an inward bowing of the medial sinus wall, sinus opacification, and a reduction in maxillary sinus size to a slit-like cavity, which suggest a diagnosis of silent sinus syndrome. This report is the first, to our knowledge, of maxillary sinus atelectasis in a non-human primate. This finding is valuable for the understanding of the pathogenesis and etiology of maxillary sinus atelectasis. At the same time, however, paleoanthropologists and primatologists may refer to this information when dealing with the interpretation of maxillary sinus pneumatization of partially broken archaeological and fossil skulls.
Kurt, Gökmen; Işeri, Haluk; Kişnişci, Reha
The purpose of this report is to describe the dentoalveolar distraction (DAD) technique and to present its effects on the surrounding structures by presenting a Class II case. A 15-year-old skeletal and dental Class II female patient with an overjet of 9 mm was treated by DAD osteogenesis. A custom-made, rigid, tooth-borne intraoral distraction device was used for rapid canine retraction. Osteotomies surrounding the canines were made to achieve rapid movement of the canines within the dentoalveolar segment, in compliance with distraction osteogenesis principles. The amount of canine retraction was 7.5 mm in 12 days at a rate of 0.625 mm per day, with no posterior anchorage loss. The canine teeth showed 1.6 mm extrusion and 11 degrees inclination change (distal tipping) during the same period. Orthodontic treatment continued for 6 months with no clinical and radiographic evidence of complications such as root fracture, root resorption, ankylosis, and soft tissue dehiscence. The DAD technique is an innovative method, because it reduces overall orthodontic treatment time by about 50%, with no unfavorable effects on periodontal tissues and surrounding structures and with no need to use any intraoral or extraoral anchorage appliances.
Sueyoshi, Ryo; Ralls, Mathew W.; Teitelbaum, Daniel H.
Background Application of distractive forces to small bowel induces intestinal growth, or enterogenesis. This emerging area of research may provide treatment for short bowel syndrome (SBS). Glucagon-like peptide 2(GLP-2) has also been reported to induce small bowel growth after bowel resection. We hypothesized that exogenous GLP-2 will result in enhanced distraction-induced enterogenesis. Methods Distraction-induced model was performed in 10-week-old C57B6 mice using osmotic forces with high molecular weight polyethylene glycol (PEG-stretch). Four groups were studied: Control group (PEG−/GLP-2−); PEG-stretch (PEG+/GLP-2−); GLP-2 control (PEG−/GLP-2+); and GLP-2 stretch (PEG+/GLP-2+). GLP-2 was given via subcutaneous osmotic pump over the 5 days of experiment. Morphology was measured by histomicrography. Epithelial cell (EC) proliferation was measured with PCNA immunofluorescent staining. Total intestinal growth and blood vessel volume was assessed with Micro CT volumetry. VEGF, FGF1 and 2, and PDGF were measured by RT-PCR. Results EC proliferation increased significantly in all groups compared to Controls, but was greatest in the GLP-2 stretch group. Diameter and length significantly increased in the PEG stretch and GLP-2 stretch groups. Moreover, there was statistically greater diameter, crypt depth and EC proliferation in the GLP-2 stretch vs. PEG stretch groups. GLP-2 stretch vessel volume was greater than all other groups and was significantly increased compared to controls. The relative expression of PDGF increased significantly in the PEG stretch group vs. the control group. Conclusions GLP-2 had an additive effect on EC proliferation, tissue growth, histomorphology and vascularization. The combination of enterogenesis and GLP-2 may yield an improved approach to treat SBS. PMID:23639355
Dhandapani, Radha Bharathi; Baskaran, Shivakumar; Arun, Kurumathur Vasudevan; Kumar, Thirunelveli Saravanan Subbu
The posterior maxillary segment frequently exhibits insufficient bone mass to support dental implants. Sinus floor augmentation enables implant placement in the posterior maxilla. This case series included ten sites, in which sinus floor elevation was done using sinus lift balloon system followed by augmentation utilizing irradiated cancellous bone allograft. Postoperative radiographic assessment of vertical bone gain was done at 3 and 6 months follow-up period. The mean initial and final bone height were 6.16 and 10.50 mm, respectively, with a mean increase of 4.34 mm at 6 months being observed with nil complication. The presented technique might represent a viable alternative for sinus elevation in posterior atrophied maxilla. Irradiated cancellous bone allograft can be advocated as an ideal bone graft material for sinus augmentation procedures. PMID:28298833
Gao, Kenneth; Sulea, Camelia; Wiederhold, Mark D.
Abstract We explored the use of virtual reality distraction techniques for use as adjunctive therapy to treat chronic pain. Virtual environments were specifically created to provide pleasant and engaging experiences where patients navigated on their own through rich and varied simulated worlds. Real-time physiological monitoring was used as a guide to determine the effectiveness and sustainability of this intervention. Human factors studies showed that virtual navigation is a safe and effective method for use with chronic pain patients. Chronic pain patients demonstrated significant relief in subjective ratings of pain that corresponded to objective measurements in peripheral, noninvasive physiological measures. PMID:24892196
Tsui, Wai Kin; Yang, Yanqi; Cheung, Lim Kwong; Leung, Yiu Yan
Abstract Background: To conduct a systematic review to answer the clinical question “What are the effectiveness of mandibular distraction osteogenesis (MDO) and its complications to treat patients with obstructive sleep apnea syndrome (OSAS)?”. Methods: A systematic search including a computer search with specific keywords, reference list search, and manual search were done. Relevant articles on MDO were assessed and selected in 3 rounds for final review based on 5 predefined inclusion criteria and followed by a round of critical appraisal. Different types of distraction and their treatment outcomes of OSAS were recorded with standardized form and analyzed. Results: Twelve articles were included in the final review. A total of 256 patients aged 7 days to 60 years were treated with either external or internal MDO, with a mean follow-up period of 6 to 37 months. The average distraction distance of 12 to 29 mm was achieved with various distraction protocols. The success rate for adult patients was 100%, and cure rates were ranged from 82% to 100%. The definition of success or cure for OSAS in children or infants was not defined. Therefore, there were no clearly reported success or cure rates for children/infants in the included studies. However, all studies reported that these patients showed significant improvement in OSAS, with many of them who avoided tracheostomy or had the tracheostomy decannulated. The complication rates were ranged from 0% to 21.4%, with most being from local wound infections or neurosensory disturbances. Conclusion: This systematic review showed that MDO was effective in resolving OSAS in adults with retrognathic mandible. MDO also showed promising results in infants or children with OSAS. From the results of this systematic review, we recommend to define the criteria of success or cure for OSAS surgery in children and infants. We also recommend setting up randomized controlled trials to compare MDO with traditional maxillomandibular
Simons-Morton, Bruce; Guo, Feng; Klauer, Sheila G; Ehsani, Johnathon P; Pradhan, Anuj K
Purpose Secondary task engagement that distracts the driver is a contributing factor to motor vehicle crashes among adults. However, the association between eye glance duration and crash risk with novice teenage drivers has not been determined. Methods Vehicles of 42 newly-licensed teenage drivers were instrumented with cameras, accelerometers, GPS, and other devices. Data were collected continuously for 18 months. Crashes and near crashes (CNCs) were identified by examining highly elevated gravitational force events. Video footage of the 6 seconds prior to each CNC and randomly sampled non-CNC road segments were coded for the duration of eye glances off the forward roadway and the presence of secondary task engagement. The likelihood (odds ratios) of CNC due to eye glance behavior was calculated by comparing the prevalence of secondary task engagement and duration of eyes off road prior to CNC with the prevalence and duration of eyes off road during non-CNC road segments. Results Crash risk increased with the duration of single longest glance during all secondary tasks (OR=3.8 for >2s) and wireless secondary task engagement (OR=5.5 for >2s). Single longest glance provided a more consistent estimate of crash risk than total time eyes off the forward roadway. Conclusions Eyes glances away from forward roadway involving secondary tasks increased the likelihood of CNC. The longer the duration of eye glance away from the road the greater the risk, regardless of type of secondary task. Education and policy discouraging secondary task engagement, particularly for prolonged periods, is warranted. PMID:24759443
Mukhopadhaya, John; Raj, Manish
Distraction osteogenesis and bone transport has been used to reconstruct bone loss defect by allowing new bone to form in the gap. Plate-guided bone transport has been successfully described in literature to treat bone loss defect in the femur, tibia, and mandible. This study reports two cases of fracture of femur with segmental bone loss treated with locking plate fixation and bone transport with Ilizarov ring fixator. At the time of docking, when the transport segment is compressed with bone fragment, the bone fragment is fixed with additional locking or nonlocking screws through the plate. The bone defect size was 7 cm in case 1 and 8 cm in case 2 and the external fixation indexes were 12.7 days/cm and 14 days/cm. No shortening was present in either of our cases. The average radiographic consolidation index was 37 days/cm. Both cases achieved infection-free bone segment regeneration and satisfactorily functional outcome. This technique reduces the duration of external fixation during the consolidation phase, allows correction of length and alignment and provides earlier rehabilitation.
Smith, Julien T.; And Others
An ethnically diverse sample of high and low hypnotizable children (N=27) suffering from cancer or blood disorders were trained along with their parents to use both distraction and hypnosis to reduce pain and anxiety. Distraction produced significant positive effects for observer-rated distress scores for the low hypnotizable children. Discusses…
Dixon, Wallace E., Jr.; Salley, Brenda J.
The authors' purpose in this study was to evaluate the role of attention, as a central dimension of temperament, in children's real-time acquisition of novel vocabulary. Environmental distractions were administered to 47 22-month-old children as they acquired novel vocabulary in a fast-mapping task. Two distraction conditions impeded novel word…
Background: Students continue to struggle with homework distraction well into the secondary school years. Recently, the concern over homework distraction has been growing, as new electronic media have offered diverse and nearly ubiquitous forms of diversion to students while they are doing homework. It is surprising to note, however, that a…
... National Highway Traffic Safety Administration Visual-Manual NHTSA Driver Distraction Guidelines for In... proposed Visual-Manual Driver Distraction Guidelines for In-Vehicle Electronic Devices. NHTSA is announcing... vehicle safely and that are operated by the driver through visual-manual means (meaning ] the...
Kahn, Christopher A; Cisneros, Victor; Lotfipour, Shahram; Imani, Ghasem; Chakravarthy, Bharath
For years, public health experts have been concerned about the effect of cell phone use on motor vehicle collisions, part of a phenomenon known as "distracted driving." The Morbidity and Mortality Weekly Report (MMWR) article "Mobile Device Use While Driving - United States and Seven European Countries 2011" highlights the international nature of these concerns. Recent (2011) estimates from the National Highway Traffic Safety Administration are that 10% of fatal crashes and 17% of injury crashes were reported as distraction-affected. Of 3,331 people killed in 2011 on roadways in the U.S. as a result of driver distraction, 385 died in a crash where at least one driver was using a cell phone. For drivers 15-19 years old involved in a fatal crash, 21% of the distracted drivers were distracted by the use of cell phones. Efforts to reduce cell phone use while driving could reduce the prevalence of automobile crashes related to distracted driving. The MMWR report shows that there is much ground to cover with distracted driving. Emergency physicians frequently see the devastating effects of distracted driving on a daily basis and should take a more active role on sharing the information with patients, administrators, legislators, friends and family.
Shimizu, Azusa; Komuro, Yuzo; Shimoji, Kazuaki; Miyajima, Masakazu; Arai, Hajime
Posterior cranial vault distraction is considered to be more effective for increasing intracranial volume than fronto-orbital advancement or anterior cranial vault expansion, but the changes in intracranial volumes after posterior cranial vault distraction remain unclear. The changes in intracranial volume were investigated in patients of premature craniosynostosis treated by this technique. Seven patients, 3 boys and 4 girls aged from 5 months to 3 years 3 months (mean 23 months) at operation, with craniosynostosis underwent posterior cranial vault distraction at Juntendo University Hospital from 2011 to 2014. Patient characteristics, length of distraction, and pre- and postoperative computed tomography findings were reviewed. Total intracranial volume, including the supratentorial space and posterior cranial fossa, was measured using the workstation functions on three-dimensional computed tomography scans. Posterior distraction was performed without severe complications except in 2 patients requiring additional surgeries. The distraction length was 22.3 to 39 mm (mean 31 mm), the intracranial volume change was 144 to 281 mL (mean 192 mL), and the enlargement ratio of intracranial volume was 113% to 134% (mean 121%). The present quantitative analysis of intracranial volume change after posterior distraction showed greater increases in intracranial volume compared with previous reports. Furthermore, intracranial volumes in our patients became nearly normal and were maintained for the follow-up period (maximum 13 months). Posterior cranial vault distraction is very effective to increase cranial volume, so may be the first choice of treatment in patients of craniosynostosis.
Cosman, Joshua D.; Vecera, Shaun P.
The ability to ignore task-irrelevant information and overcome distraction is central to our ability to efficiently carry out a number of tasks. One factor shown to strongly influence distraction is the perceptual load of the task being performed; as the perceptual load of task-relevant information processing increases, the likelihood that…
Jarosz, Andrew F.; Wiley, Jennifer
Current theories concerning individual differences in working memory capacity (WMC) suggest that WMC reflects the ability to control the focus of attention and resist interference and distraction. The current set of experiments tested whether susceptibility to distraction is partially responsible for the established relationship between…
Purpose This study investigated the relationship between the roots of the maxillary molars and the maxillary sinus using cone beam computed tomography (CBCT), and measured the distances between the roots of the maxillary molars and the sinus floor as well as the thickness of the bone between the root and the alveolar cortical plate. Materials and Methods The study sample consisted of 83 patients with normally erupted bilateral maxillary first and second molars. A total of 332 maxillary molars were examined using CBCT images. The vertical relationship of each root with the maxillary sinus was classified into four types on CBCT cross-sectional images. The distance between the sinus floor and root and the bone thickness between the root and alveolar cortical plate were measured. Results In the buccal roots of the maxillary molars, a root protruding into the sinus occurred most frequently. A root projecting laterally along the sinus cavity was most common in the palatal roots of the maxillary first molars. The mesiobuccal roots of the maxillary second molar were closest to the sinus. The mesiobuccal roots of the first molars were closest to the cortical plate. Conclusion The relationship between the roots of the maxillary molars and the sinus differed between the buccal and palatal roots. A root protruding into the sinus occurred more frequent in the buccal roots of the maxillary molars. The mesiobuccal root of the maxillary second molar was closest to the maxillary sinus floor and farthest from the alveolar cortical plate. PMID:23301207
Golen, Rebecca B; Ventura, Alison K
Mindless eating, or eating while distracted by surrounding stimuli, leads to overeating. The present study explored whether "mindless feeding," or maternal distraction during bottle-feeding, is associated with greater infant formula/milk intakes and lower maternal sensitivity to infant cues. Mothers and their ≤24-week-old bottle-feeding infants (N = 28) visited our laboratory for a video-recorded feeding observation. Infant intake was assessed by weighing bottles before and after the feedings. Maternal sensitivity to infant cues was objectively assessed by behavioral coding of video-records using the Nursing Child Assessment Feeding Scale. Maternal distraction was defined as looking away from the infant >75% of the feeding; using a mobile device; conversing with another adult; or sleeping. Twenty-nine percent (n = 8) of mothers were distracted. While differences in intakes for infants of distracted vs. not distracted mothers did not reach significance (p = 0.24), the association between distraction and infant intake was modified by two dimensions of temperament: orienting/regulation capacity (p = 0.03) and surgency/extraversion (p = 0.04). For infants with low orienting/regulation capacity, infants of distracted mothers consumed more (177.1 ± 33.8 ml) than those of not distracted mothers (92.4 ± 13.8 ml). Similar findings were noted for infants with low surgency/extraversion (distracted: 140.6 ± 22.5 ml; not distracted: 78.4 ± 14.3 ml). No association between distraction and intake was seen for infants with high orienting/regulation capacity or surgency/extraversion. A significantly greater proportion of distracted mothers showed low sensitivity to infant cues compared to not distracted mothers (p = 0.04). In sum, mindless feeding may interact with infant characteristics to influence feeding outcomes; further experimental and longitudinal studies are needed.
Nagai, Kanto; Muratsu, Hirotsugu; Matsumoto, Tomoyuki; Miya, Hidetoshi; Kuroda, Ryosuke; Kurosaka, Masahiro
The influence of joint distraction force on intraoperative soft tissue balance was evaluated using Offset Repo-Tensor® for 78 knees that underwent primary posterior-stabilized total knee arthroplasty. The joint center gap and varus ligament balance were measured between osteotomized surfaces using 20, 40 and 60 lbs of joint distraction force. These values were significantly increased at extension and flexion as the distraction force increased. Furthermore, lateral compartment stiffness was significantly lower than medial compartment stiffness. Thus, larger joint distraction forces led to larger varus ligament balance and joint center gap, because of the difference in soft tissue stiffness between lateral and medial compartments. These findings indicate the importance of the strength of joint distraction force in the assessment of soft tissue balance, especially when using gap-balancing technique.
Fletcher, Matt D A
Distraction arthroplasty of the ankle, elbow, and hip has become widely accepted and used within the orthopaedic community with excellent initial results which appear sustained. To date it has not been applied to the wrist in the same manner. A novel technique, drawn upon past success of articulated ankle distraction and static wrist distraction, was devised and evaluated by application of articulated wrist distraction performed over a 12-week period in a patient with poor functional outcome following limited wrist fusion. Posttreatment results showed improvement in range of motion (100-degree arc), subjective pain, and functional outcome measures (DASH 21.7, Mayo Wrist Score 80) comparable or better than either limited wrist fusion or proximal row carpectomy. Articulated wrist distraction initially appears to be a promising therapeutic option for the management of the stiff and painful wrist to maintain maximal function for which formal wrist arthrodesis may be the only alternative.
Swedler, David I; Pollack, Keshia M; Gielen, Andrea C
A concurrent mixed methods design was used to explore personal and workplace factors, informed by the Theory of Planned Behavior, that affect truck drivers' decision-making about distracted driving on the job. Qualitative data were collected via semi-structured interviews with experts in truck safety and distracted driving, and quantitative data were collected via online survey of truck drivers in the United States. Findings from the interviews illustrated how drivers perceived distractions and the importance of supervisors enforcing organizational distracted driving policies. Survey results found that behavioral intentions were most important in regards to texting and crash and near-crash outcomes, while perceived norms from management best described the correlation between dispatch device use and negative crash-related outcomes. By using a mixed methods design, rather than two separate studies, these findings revealed nuanced differences into the influence of supervisors on distracted driving.
Prabhakar, A R; Marwah, N; Raju, O S
Pain is not the sole reason for fear of dentistry. Anxiety or the fear of unknown during dental treatment is a major factor and it has been the major concern for dentists for a long time. Therefore, the main aim of this study was to evaluate and compare the two distraction techniques, viz, audio distraction and audiovisual distraction, in management of anxious pediatric dental patients. Sixty children aged between 4-8 years were divided into three groups. Each child had four dental visits--screening visit, prophylaxis visit, cavity preparation and restoration visit, and extraction visit. Child's anxiety level in each visit was assessed using a combination of four measures: Venham's picture test, Venham's rating of clinical anxiety, pulse rate, and oxygen saturation. The values obtained were tabulated and subjected to statistical analysis. It was concluded that audiovisual distraction technique was more effective in managing anxious pediatric dental patient as compared to audio distraction technique.
Bishop, Sonia J; Cohen, Jonathan D; Fossella, John; Casey, B J; Farah, Martha J
Early studies of genetic effects on brain activity have been conducted to investigate primarily either the influence of polymorphisms in dopaminergic genes, especially the catechol-O-methyltransferase (COMT) gene, on prefrontal cognitive processes such as working memory, or that of polymorphisms in the serotonin transporter gene on the amygdala response to threatening stimuli. Here, we address genetic influences on the neural systems underlying cognitive-affective interactions. Specifically, we assess the effect of the CO MT val158met polymorphism onfrontal regulation of attentionunder emotional distraction. Healthy volunteers were scanned while performing a house-matching task with affectively negative versus neutral distractors. Effects of val allele load were examined on frontal regions associated with attentional control and emotion regulation, and on parahippocampal regions associated with perception of houses. As we predicted, val load correlated positively with activity in control- and task-related regions during performance under emotional distraction. These findings provide an initial step toward identifying genetic contributions to interindividual variability in recruitment of mechanisms that regulate affective processing.
CILDAG, SONGUL; SENTURK, TASKIN; SARGIN, GOKHAN
Background Some patients may have psychosomatic complaints due to their previous experiences during the drug hypersensitivity reaction. Worry about being hurt due to an administered drug is termed nocebo effect, which is the opposite of the placebo effect. In our study, we investigated the effect of distraction on symptoms during drug provocation test. Methods Our study included 112 patients who underwent DPTs for alternative purposes in our clinic. Previous hypersensitivity reactions of all the patients had objective signs. Patients were divided into two groups for the DPT. Sixty-three patients were kept busy during the test, performing tasks such as filling questionnaires, arranging files in alphabetical and numerical order, and doing archiving (Group 1). Forty-nine patients did not perform any tasks during the test (Group 2). Reactions that occurred during the test were recorded. Results During the DPT, 5 patients in Group 1 (5/63, 7.9%) and 17 patients in Group 2 (17/49, 34.7%), i.e. a total of 22 patients (22/112, 19.6%), had a reaction. There was a statistically significant difference between Group 1 and Group 2 according to the frequency of the reaction development. Conclusions Patient psychosomatic complaints during DPTs are proportional to their association with previous allergic reactions. In order to prevent such reactions, it may be beneficial to keep the patients busy with an activity in order to distract them during the test. PMID:28246492
Ong, Juling; Harshbarger, Raymond J.; Kelley, Patrick; George, Timothy
The rapid growth of the brain in the first few years of life drives the expansion of the cranial vault. This expansion occurs primarily at the cranial sutures; premature fusion of these results in growth restriction perpendicular to the axis of the suture. The result of this is physical deformation of the cranial and facial skeleton, as well as the distortion of the underling brain and its physiology. These patients can present with symptoms of raised intracranial pressure, neurodevelopmental delay, as well as the morphological features of craniosynostosis. Acquired conditions such as the slit ventricle syndrome may also result in cephalocranial disproportion with these clinical features. Traditional vault remodeling surgery is able to correct the physical abnormalities as well as correcting cephalocranial disproportion. Its limitations include the degree of scalp expansion achievable as well as resulting defects in the bone. The use of distraction osteogenesis of the cranial vault permits a controlled expansion in a predetermined vector in a gradual manner. When used in the calvarium, this combines the benefits of tissue expansion on the scalp, as well as stimulating the production of new bone, reducing the defects resulting from expansion. In this review, the authors describe some of the surgical considerations important to the use of this technique. This includes the relevant anatomy and technical aspects illustrated with the use of clinical cases. Finally, they present a summary of their experience and discuss the complications associated with cranial vault distraction osteogenesis. PMID:25383052
Lieberman, Matthew D; Inagaki, Tristen K; Tabibnia, Golnaz; Crockett, Molly J
Although multiple neuroimaging studies suggest that affect labeling (i.e., putting feelings into words) can dampen affect-related responses in the amygdala, the consequences of affect labeling have not been examined in other channels of emotional responding. We conducted four studies examining the effect of affect labeling on self-reported emotional experience. In study one, self-reported distress was lower during affect labeling, compared to passive watching, of negative emotional pictures. Studies two and three added reappraisal and distraction conditions, respectively. Affect labeling showed similar effects on self-reported distress as both of these intentional emotion regulation strategies. In each of the first three studies, however, participant predictions about the effects of affect labeling suggest that unlike reappraisal and distraction, people do not believe affect labeling to be an effective emotion regulation strategy. Even after having the experience of affect labels leading to lower distress, participants still predicted that affect labeling would increase distress in the future. Thus, affect labeling is best described as an incidental emotion regulation process. Finally, study four employed positive emotional pictures and here, affect labeling was associated with diminished self-reported pleasure, relative to passive watching. This suggests that affect labeling tends to dampen affective responses in general, rather than specifically alleviating negative affect.
Kettwich, Carmen; Klinger, Karsten; Lemmer, Uli
Nowadays drivers have to get along with an increasing complex visual environment. More and more cars are on the road. There are not only distractions available within the vehicle, like radio and navigation system, the environment outside the car has also become more and more complex. Hoardings, advertising pillars, shop fronts and video screens are just a few examples. For this reason the potential risk of driver distraction is rising. But in which way do the advertisements at the roadside influence the driver's attention? The investigation which is described is devoted to this topic. Various kinds of advertisements played an important role, like illuminated and non-illuminated posters as well as illuminated animated ads. Several test runs in an urban environment were performed. The gaze direction of the driver's eye was measured with an eye tracking system. The latter consists of three cameras which logged the eye movements during the test run and a small-sized scene camera recording the traffic scene. 16 subjects (six female and ten male) between 21 and 65 years of age took part in this experiment. Thus the driver's fixation duration of the different advertisements could be determined.
Sugiura, Tsutomu; Yamamoto, Kazuhiko; Nakashima, Chie; Murakami, Kazuhiro; Matsusue, Yumiko; Horita, Satoshi; Sakagami, Go; Kirita, Tadaaki
We report a case of chronic maxillary sinusitis caused by denture lining material entering through an oroantral fistula after tooth extraction. The patient was an 80-year-old female who visited us with a complaint of pus discharge from the right posterior maxilla. She had extraction of the upper right second molar and had her upper denture relined with silicone lining material. The patient noticed swelling of the right cheek and purulent rhinorrhea 20 days before her first visit to our clinic. Oral examination showed an oroantral fistula with a diameter of 3 mm in the posterior alveolar ridge of the right maxilla. Computed tomography revealed a hyperdense foreign body in the right maxillary sinus and thickening of the mucosal lining. Under diagnosis of maxillary sinusitis caused by a foreign body, endoscopic maxillary surgery was performed simultaneously with the removal of the foreign body. The foreign body removed was 12 × 6 mm in size, oval in shape, light pink in color, and compatible with silicone denture lining material. During the follow-up it was observed that the oroantral fistula closed spontaneously after the removal of the foreign body. The maxillary sinus was in a good shape without recurrence of sinusitis seven months after surgery.
Kilkis, Dogan; Bayram, Mehmet; Celikoglu, Mevlut; Nur, Metin
The aim of this study was to present the orthodontic treatment of a 15-year-old boy with a unilateral maxillary molar distalization system, called the zygoma-gear appliance. It consisted of a zygomatic anchorage miniplate, an inner bow, and a Sentalloy closed coil spring (GAC International, Bohemia, NY). A distalizing force of 350 g was used during the distalization period. The unilateral Class II malocclusion was corrected in 5 months with the zygoma-gear appliance. The maxillary left first molar showed distalization of 4 mm with an inclination of 3°. The maxillary premolars moved distally with the help of the transseptal fibers. In addition, there were slight decreases in overjet (-0.5 mm) and maxillary incisor inclination (-1°), indicating no anchorage loss from the zygoma-gear appliance. Preadjusted fixed appliances (0.022 × 0.028-in, MBT system; 3M Unitek, Monrovia, Calif) were placed in both arches to achieve leveling and alignment. After 14 months of unilateral distalization with the zygoma-gear appliance and fixed appliances, Class I molar and canine relationships were established with satisfactory interdigitation of the posterior teeth. Acceptable overjet and overbite were also achieved. This article shows that this new system, the zygoma-gear appliance, can be used for unilateral maxillary molar distalization without anchorage loss.
Sugiura, Tsutomu; Yamamoto, Kazuhiko; Nakashima, Chie; Murakami, Kazuhiro; Matsusue, Yumiko; Horita, Satoshi; Sakagami, Go; Kirita, Tadaaki
We report a case of chronic maxillary sinusitis caused by denture lining material entering through an oroantral fistula after tooth extraction. The patient was an 80-year-old female who visited us with a complaint of pus discharge from the right posterior maxilla. She had extraction of the upper right second molar and had her upper denture relined with silicone lining material. The patient noticed swelling of the right cheek and purulent rhinorrhea 20 days before her first visit to our clinic. Oral examination showed an oroantral fistula with a diameter of 3 mm in the posterior alveolar ridge of the right maxilla. Computed tomography revealed a hyperdense foreign body in the right maxillary sinus and thickening of the mucosal lining. Under diagnosis of maxillary sinusitis caused by a foreign body, endoscopic maxillary surgery was performed simultaneously with the removal of the foreign body. The foreign body removed was 12 × 6 mm in size, oval in shape, light pink in color, and compatible with silicone denture lining material. During the follow-up it was observed that the oroantral fistula closed spontaneously after the removal of the foreign body. The maxillary sinus was in a good shape without recurrence of sinusitis seven months after surgery. PMID:27386012
Amir, Lisa R; Becking, Alfred G; Jovanovic, Andreas; Perdijk, Frits B T; Everts, Vincent; Bronckers, Antonius L J J
Vertical distraction osteogenesis has received considerable interest as a way to augment bone prior to implant placement. However, very little is known regarding the appropriate distraction protocols in the human mandible. In this study, we evaluate the effect of the distraction rate and the duration of neutrofixation on bone formation and closure of the gap in the human mandible. Vertical distraction was performed in the atrophic mandible of 16 edentulous patients, aged 62+/-6 years. The bone was distracted for approximately 10 mm at a rate of either 0.5 or 1 mm/day. Bone biopsies were taken after 7-20 weeks of neutrofixation. Histological analysis demonstrated newly formed bone in the distraction gap in all biopsies. The bone was predominantly of the woven type. After 10 weeks of neutrofixation, the gap was bridged by new bone in two out of three intact samples in the 0.5 mm/day group, but not in two intact samples of the 1 mm/day group. Histomorphometry revealed longer bone trabeculae (P=0.02) and a somewhat increased bone volume in the area where new bone formation started (P=0.07) in the group of patients having the 0.5 mm/day of distraction rate than in the 1 mm/day group. We conclude that in elderly patients, a distraction rate of 0.5 mm/day results in faster osteogenesis in the distraction gap than a rate of 1 mm/day. A minimum of 10 weeks of neutrofixation seems to be needed to close a 10 mm gap after cessation of distraction.
Carrillo Andrades, Vicente Alfonso; Carrillo Venezian, Bernardita Claudia
Mucoceles are not often found in the maxillary sinus, and is a rare surgery complication, in this case, orthognathic. This review describes a mucocele that partially occupies the right maxillary sinus, causing a chronic nasal obstruction. This is the case of a 44 year-old female patient, which after 12 years of several orthognathic surgeries, presents facial pain and right nasal obstruction. The paranasal sinus computed tomography reveals a mass with liquid content that occupies the lower part of the right maxillary sinus and compromises the right nasal cavity. The patient was treated with an intranasal marsupialization and a middle meatotomy with endoscopic nasal approach. Evolution was satisfactory two years after the intervention.
Rodríguez Gutiérrez, Carlos; Rodríguez Gómez, Enrique
Benign paroxysmal positional vertigo (BPPV) is the most common form of vertigo. It is caused by loose otoconia from the utricle which, in certain positions, displaced the cupula of the posterior semicircular canal. BPPV most often is a result of aging. It also can occur after a blow to the head. Less common causes include a prolonged positioning on the back (supine) during some surgical procedures. Additionally one can include in this ethiopathogenesis the positioning required during the maxillary dental implant surgery with bone regeneration related to a forced head positioning and inner ear trauma induced by dental turbine noise working in the maxillary bone. Two cases of patients who suffered BPPV after undergoing maxillary dental implant with bone regeneration procedures are reported. Diagnosis and treatment are also described.
Paoloni, Valeria; Pavoni, Chiara; Mucedero, Manuela; Bollero, Patrizio; Laganà, Giuseppina; Cozza, Paola
Summary Aim To provide clinicians with useful information for immediate diagnosis and management of impacted maxillary incisors due to trauma. Methods We present a case of post-traumatic impaction of a central right maxillary incisor in a young patient. The treatment plan consisted in the interceptive management (surgical and orthodontic), the valuation of the necessary space to move the impacted tooth in the normal position and the biomechanical approach for anchorage, avoiding prosthetic/implants replacement. Results The therapy of an impacted maxillary incisor due to trauma requires a multidisciplinary approach: orthodontic, surgical, endodontic and periodontal considerations are essential for successful treatment. Conclusions Surgical exposure and orthodontic traction is the treatment most often used in case of posttraumatic impacted incisor: this technique in fact can lead to suitable results at the periodontal, occlusal and esthetics levels at an early stage and more definitively than with other treatment options. PMID:23991268
Olson, David G; Roberts, Steven; Joyce, Anthony P; Collins, D Edward; McPherson, James C
This study examined the incisoapical extent of the apical constriction in 45 human maxillary central incisors. The null hypothesis was that the apical constriction is a flat ring. Our working hypothesis was that the constriction is actually uneven or "skewed" as it traces a path around the circumference of the canal. Teeth were split and imaged with 25x magnification, and the most apical and coronal limits of the apical constriction were identified and measured. Analysis of the data indicates that a majority (>70%) of maxillary central incisors exhibit an unevenness or "skew" of the apical constriction of greater than 100 microm in the incisoapical dimension, with a maximum measured skew of 385 microm. On the basis of the results of this study, a statistically significant (P < .05) variation in the longitudinal position of the apical constriction around its circumference was confirmed in maxillary central incisors.
Paparella, María Luisa; Brandizzi, Daniel; Santini-Araujo, Eduardo; Cabrini, Rómulo Luis
Maxillary osteosarcomas are a relatively frequent malignant tumor of the oral cavity. Similarly to other skeletal osteosarcomas, they exhibit different cellular differentiation patterns, i.e. chondroblastic, osteoblastic, or fibroblastic. Although their histological features resemble those of osteosarcomas of the long bones, their pattern of evolution usually differs. Morphometric variations in silver stained Nucleolar Organizer Regions (AgNOR) have proved of value to study the biology of several tumors. However, information on the analysis of AgNOR in maxillary tumors is scarce. The aim of the present study was to analyze the variations of different morphological parameters related to AgNOR in a series of 32 cases of maxillary osteosarcoma. In each case we analyzed 100 nuclei corresponding to the prevalent cellular differentiation type, selecting the most aggressive area. We employed software previously developed at our laboratory that yields information on different AgNOR-related parameters. The results were compared with those previously reported in a study on 12 cases of osteosarcoma of long bones. Six cases of oral mucosa squamous cell carcinoma were also included for comparative purposes. Single AgNOR volume proved to be the most discriminatory and informative parameter. The value of single AgNOR volume was considerably lower in mandible osteosarcomas than in osteosarcomas of the upper maxilla (p=0.02). The values were significantly lower in maxillary osteosarcomas than in long bone osteosarcomas and in oral carcinomas. This finding would suggest a slower rate of cell activity in maxillary osteosarcomas, associated in turn to its known lower degree of aggressiveness. The present results suggest that the analysis of AgNOR is a valuable and easily applicable marker to determine the degree of malignancy and biology of maxillary osteosarcomas.
Soukup, Jason W; Drees, Randi; Koenig, Lisa J; Snyder, Christopher J; Hetzel, Scott; Miles, Chanda R; Schwarz, Tobias
The objective of this blinded study was to validate the use of cone beam computed tomography (C) for imaging of the canine maxillary dentoalveolar structures by comparing its diagnostic image quality with that of 64-multidetector row CT Sagittal slices of a tooth-bearing segment of the maxilla of a commercially purchased dog skull embedded in methylmethacrylate were obtained along a line parallel with the dental arch using a commercial histology diamond saw. The slice of tooth-bearing bone that best depicted the dentoalveolar structures was chosen and photographed. The maxillary segment was imaged with cone beam CT and 64-multidetector row CT. Four blinded evaluators compared the cone beam CT and 64-multidetector row CT images and image quality was scored as it related to the anatomy of dentoalveolar structures. Trabecular bone, enamel, dentin, pulp cavity, periodontal ligament space, and lamina dura were scored In addition, a score depicting the evaluators overall impression of the image was recorded. Images acquired with cone beam CT were found to be significantly superior in image quality to images acquired with 64-multidetector row CT overall, and in all scored categories. In our study setting cone beam CT was found to be a valid and clinically superior imaging modality for the canine maxillary dentoalveolar structures when compared to 64-multidetector row CT.
Müsebeck, K; Rosenberg, H
Anemometry with the hot wire and hot film technique previously described, enables the rhinologist to record slow and rapidly changing air flow in the maxillary sinus. The advantages and disadvantages of this method are considered. Anemometry together with manometry may be designated sinumetry and used as a diagnostic procedure following sinuscopy in chronic maxillary sinus disease. The value of the function from velocity of time allows the estimation of flow-volume in the sinus. Furthermore, the method is useful to evaluate the optimal therapy to restore ventilation in the case of an obstructed ostium demonstrated before and after surgical opening in the inferior meatus.
Kishan, K. V.; Hegde, Vani; Ponnappa, K. C.; Girish, T. N.; Ponappa, M. C.
This study is to report the rare localization of a radicular groove on the palatal aspect of the maxillary lateral incisor and to discuss the pathology and management of the concomitant endo-periodontal defect. Unilateral palato-radicular groove was located on the Maxillary right lateral incisor of an 18-year-old female patient. The groove was associated with deep local periodontal pocket resulting in pulp necrosis and the formation of a large periapical lesion. A collaborative management was carried out using a combination of endodontic therapy, surgical enucleation, odontoplasty, and periodontal regenerative procedure resulting the successful healing of the periapical lesion. PMID:24678222
Suresh, Kotumachagi Sangappa; Uma, HL; Nagarathna, J
ABSTRACT Eruption disturbances related to the position include ectopic eruption and transpositions. The occurrence of ectopic eruption is most commonly associated with maxillary incisors. The normal eruption, position and morphology of these teeth are crucial to craniofacial development, facial esthetics as well as phonetics. It is essential that the clinicians have thorough knowledge of the eruption disturbances in order to make an appropriate, as well as timely intervention, as dictated by the complexity of the problem. How to cite this article: Suresh KS, Uma HL, Nagarathna J, Kumar P. Management of Ectopically Erupting Maxillary Incisors: A Case Series. Int J Clin Pediatr Dent 2015;8(3):227-233. PMID:26604543
Jafari-Pozve, Nasim; Sheikhi, Mahnaz; Ataie-Khorasgani, Masoud; Jafari-Pozve, Shahram
Maxillary sinus aplasia and hypoplasia are rare conditions that can cause symptoms such as headaches and voice alteration. The majority of patients are asymptomatic, but these conditions must be noticed for importance of differential diagnosis such as infection and neoplasms. Conventional radiographs could not differentiate between inflammatory mucosal thickening, neoplasm, and hypoplasia of the sinus. Computed tomography (CT) and also cone beam computed tomography (CBCT) are the proper modalities to detect these conditions. In the present study, CBCT findings of three cases with maxillary sinus hypoplasia and aplasia are reported. PMID:25426156
Lentner, Mark; Li, Hui; Nagorsky, Matthew
Actinomycosis is a bacterial infection due to Actinomyces israelii, a gram-positive, anaerobic organism that normally affects the cervicofacial region. However, facial injury or trauma (i.e., dental procedures) can allow this bacteria to inhabit other regions. There have been rare reports of actinomycosis of the paranasal sinuses. We present a case of a 50-year-old female who originally presented with a suspected oroantral fistula who subsequently was found to have actinomycosis involving her right maxillary sinus. Additionally, the dental extraction site revealed no connection with the maxillary sinus. We discuss the diagnostic approach and management of this patient as it relates to the limited existing literature.
Suresh, Kotumachagi Sangappa; Uma, H L; Nagarathna, J; Kumar, Pravin
Eruption disturbances related to the position include ectopic eruption and transpositions. The occurrence of ectopic eruption is most commonly associated with maxillary incisors. The normal eruption, position and morphology of these teeth are crucial to craniofacial development, facial esthetics as well as phonetics. It is essential that the clinicians have thorough knowledge of the eruption disturbances in order to make an appropriate, as well as timely intervention, as dictated by the complexity of the problem. How to cite this article: Suresh KS, Uma HL, Nagarathna J, Kumar P. Management of Ectopically Erupting Maxillary Incisors: A Case Series. Int J Clin Pediatr Dent 2015;8(3):227-233.
Sukh, Ram; Singh, Gyan P.; Tandon, Pradeep
Interdisciplinary approach for the management of malocclusion provides a holistic approach of patient management. Prudent treatment planning is necessary to achieve the various treatment goals. This case report describes the orthodontic management of a 16-year-old adolescent female patient with bilateral labially impacted maxillary canines. The problems associated with impacted maxillary canines and the biomechanical interventions used for this patient are discussed. The treatment protocol involved surgical intervention, followed by sequential traction of the impacted teeth. An interdisciplinary approach to treatment with different mechanical strategies led to the achievement of the desired esthetic, functional, and occlusal treatment goals. PMID:25395776
de Mendonça, Marcos Rogério; Verri, Ana Caroline Gonçales; Martins, Lídia Pimenta; Fabre, Aubrey Fernando; Cuoghi, Osmar Aparecido
Impaction of maxillary canines can be prevented by early intervention in the mixed dentition phase after the correct diagnosis of malocclusion, reducing the complexity of the treatment. This article reports the case of a 10-year-old patient who possessed impacted maxillary canines and, after early extraction of primary canines, had reestablished favorable permanent successors' eruption axis. This 5-year radiographic follow-up study with panoramic radiography shows that this can be used in practice and that an effective control strategy ensures the accuracy in the inclination of the impacted canines. Treatment success is related to early diagnosis and strategic interceptive treatment choice.
Kondo, S; Hanamura, H; Wakatsuki, E
The crown dimensions of the maxillary molars in Tupaia glis were measured, and the most common molar size sequence was M1 > M2 > M3. The M2 and M3 molars were smaller than the M1 in the mesiodistal crown diameters. With regard to the buccolingual diameters, the distal part of M1 and mesial part of M2 were relatively larger and less variable in size. This stable area corresponded to the inflection point of the maxillary arch curve. These results could be explained from a functional morphological standpoint.
Sulaiman, A.O; Dosumu, O.O; Amedari, McKing
The maxillary first premolar is the most commonly bi- rooted tooth with occasional presentation of three roots system; it is a transitional tooth between incisors and molars. Although it usually has two canals, it may rarely have three and this third canal can easily be missed. Thus meticulous knowledge of tooth morphology, careful interpretation of angled radiographs, proper access cavity preparation and a detailed exploration of the interior of the tooth is needed to ensure a proper endodontic treatment. This article reports a rare finding of three canals in a maxillary first premolar with non well defined root outline radiographically during an elective root canal treatment. PMID:25161429
Rai, Anshul; Rai, Neha J; Rai, Monika A; Jain, Gauravi
Only few cases of ectopic third molar in relation to the roof of maxillary sinus and posteroinferior to the floor of the orbit have been reported in the literature. The diagnosis is usually done by plain-film radiography. "Caldwell-Luc" operation or endoscopic procedures have been used for the removal of such type of ectopic tooth. We report a case of 46-year-old female patient who presented with pain, swelling and watering of eye due to the ectopic tooth. The trans oral removal (via "Caldwell-Luc" operation) of the ectopic maxillary third molar situated superior to maxillary antrum and posteroinferior to the floor of orbit has been described in this case without any complication.
Mandibular distraction osteogenesis has become an accepted alternative treatment for infants and children with upper airway obstruction associated with micrognathia. Several reports exist that purport the efficacy of mandibular distraction in these patients, such as preventing tracheostomy or facilitating tracheostomy removal. However, the majority of these studies are retrospective reviews with small cohorts and relatively short-term follow-up. Consequently, the ideal indications, pre- and postoperative evaluation, timing, and treatment are subject to controversy and not currently well established. Significantly less attention has been given to short- and long-term complications of mandibular distraction, such as effects on the developing tooth buds, impact on future mandibular development, and temporomandibular joint abnormalities. This article reviews the basic principles of distraction osteogenesis, summarizes the outcomes of recent literature involving pediatric mandibular distraction including this author's experience, and discusses the known and potential adverse sequelae of mandibular distraction. Before a clearly defined role of mandibular distraction in the treatment of infants with micrognathia-associated upper airway obstruction can be established, additional prospective studies are necessary to delineate its benefits and limitations.
Lacefield, Katharine; Negy, Charles
The present study examined 100 lesbian and gay college students and 100 heterosexual students to determine whether group differences exist in frequency of a range of non-erotic cognitive distractions during sexual activity. Non-erotic cognitive distraction is a descriptive term for both self-evaluative cognitions related to physical performance and body image concerns, as well as additional cognitive distractions (e.g., contracting an STI or emotional concerns) during sexual activity. Participants were matched on gender (96 males and 104 females), age, and ethnicity, and completed questionnaires assessing frequency of non-erotic cognitive distractions during sexual activity, as well as measures of additional variables (trait and body image anxiety, attitudes toward sexual minorities, self-esteem, and religiosity). Results indicated that sexual minorities experienced significantly more cognitive distractions related to body image, physical performance, and STIs during sexual activity than heterosexuals. Regarding gender, men reported more distractions related to STIs than women. Interaction effects were observed between sexual orientation and gender for body image-, disease-, and external/emotional-based distractions. Implications of these findings are discussed.
Reisenauer, Renate; Dreisbach, Gesine
The goal of the study was to investigate whether task rules are automatically applied to irrelevant distracters. In three experiments, subjects categorized target words which were superimposed on distracter pictures. The categorization rule was arbitrary and the distracters were not relevant at any point during the experiment. We found congruency effects for distracters that belonged to the task-relevant categories, but were never presented as target words. Responses were faster when target and distracter belonged to the same category, i.e., were mapped to the same response, than when they were mapped to different responses. Since the distracters were never responded to in the course of the experiment, interference caused by retrieval of S-R episodes cannot explain the results. Instead, we propose that even arbitrary categorization rules are applied to all suitable stimuli, including distracters. Results are taken as evidence that a currently relevant task rule enhances processing of target-related information thereby increasing interference by task related, but currently irrelevant information.
Anitha, K.; Kumar, S. Senthil; Babu, M. R. Ramesh; Candamourty, Ramesh; Thirumurugan
Aim: The aim of the study was to evaluate the osseo-integration and soft tissue status of the endosseous implants placed in immediate extraction socket. Methodology: Seven patients (4 males and 3 females) aged 20-30 years were selected for the study. Nine implants were placed in seven patients in the maxillary arch. All the patients were clinically αnd thoroughly examined. Under local anesthesia, the indicated tooth was extracted. The extracted socket was prepared using standard drills with palatal wall as guide. The longest and widest implants were placed (Hi-Tec Implants). All implants showed good primary stability. The implants used in the study were tapered design endosseous implants with Threaded implants (TI) unit plasma-sprayed surface. Surgical re-entry (secondary surgery) was performed to remove the healing cap after 6 months for supra crestal fabrication. All patients were reviewed periodically at 3rd and 6th month interval and the following clinical parameters including modified plaque index (mPlI), modified bleeding index (mBI), probing depth (PD), attachment level (AL), and distance between the implant shoulder and mucosal margin (DIM), distance between the implant shoulder and first bone-implant contact, and Clinical Mobility Index were recorded. The results were computed and subjected to statistical evaluation. Results: The mPlI, mBI, PD, AL, and DIM were evaluated around the implants at baseline, 3rd and 6th month intervals and analyzed statistically by Friedman T-test. The results of the above were shown to be statistically non-significant. The distance between the implant shoulder and first bone implant contact was evaluated around the implants at base line, 3rd and 6th month intervals. The results proved to be statistically significant (0.01) implying that there was a bone apposition around the implants. Conclusion: During the course of the study, soft tissue status around implants was found to be healthy. Osseointegration as assessed by
Magill, John C.; Byl, Marten F.; Goldwaser, Batya; Papadaki, Maria; Kromann, Roger; Yates, Brent; Morency, Joseph R.; Kaban, Leonard B.; Troulis, Maria J.
Background Distraction osteogenesis (DO) is a technique of bone lengthening that makes use of the body’s natural healing capacity. An osteotomy is created and a rigid distraction device is attached to the bone. After a latency period, the device is activated 2–4 times per day for a total of 1 mm/day of bone lengthening. This technique is used to correct a variety of congenital and acquired deformities of the mandible, midface and long bones. To shorten the treatment period and to eliminate the complications of patient activation of the device, an automated continuous distraction device would be desirable. It has been reported that continuous distraction generates adequate bone with lengthening at a rate of 2 mm/day, thereby reducing the treatment time. Method of Approach The device we describe here uses miniature high-pressure hydraulics, position feedback, and a digital controller to achieve closed-loop control of the distraction process. The implanted actuator can produce up to 40N of distraction force on linear trajectories as well as curved distraction paths. In the paper we detail the spring-powered hydraulic reservoir, controller, and user interface. Results Experiments to test the new device design were performed in a porcine cadaver head and in live pigs. In the cadaver head, the device performed an 11-day/11 mm distraction with a root-mean-squared position error of 0.09 mm. The device functioned for periods of several days in each of five live animals, though some component failures occurred, leading to design revisions. Conclusions The test series showed that the novel design of this system provides the capabilities necessary to automate distraction of the mandible. Further developments will focus on making the implanted position sensor more robust and then carrying out clinical trials. PMID:20740071
Deshpande, Sagar S.; Gallagher, Kathleen K.; Donneys, Alexis; Nelson, Noah S.; Guys, Nicholas P.; Felice, Peter A.; Page, Erin E.; Sun, Hongli; Krebsbach, Paul H.; Buchman, Steven R.
Background Radiotherapy is known to be detrimental to bone and soft-tissue repair. Bone marrow stromal cells have been shown to enhance bone regeneration during distraction osteogenesis following radiation therapy. The authors posit that transplanted bone marrow stromal cells will significantly augment the mandibular vascularity devastated by radiation therapy. Methods Nineteen male Lewis rats were split randomly into three groups: distraction osteogenesis only (n = 5), radiation therapy plus distraction osteogenesis (n = 7), and radiation therapy plus distraction osteogenesis with intraoperative placement of 2 million bone marrow stromal cells (n = 7). A mandibular osteotomy was performed, and an external fixator device was installed. From postoperative days 4 through 12, rats underwent a gradual 5.1-mm distraction followed by a 28-day consolidation period. On postoperative day 40, Microfil was perfused into the vasculature and imaging commenced. Vascular radiomorphometric values were calculated for regions of interest. An analysis of variance with post hoc Tukey or Games-Howell tests was used, dependent on data homogeneity. Results Stereologic analysis indicated significant remediation in vasculature in the bone marrow stromal cell group compared with the radiation therapy/distraction osteogenesis group. Each of five metrics idicated significant improvements from radiation therapy/distraction osteogenesis to the bone marrow stromal cell group, with no difference between the bone marrow stromal cell group and the distraction osteogenesis group. Conclusions Bone marrow stromal cells used together with distraction osteogenesis can rejuvenate radiation-impaired vasculogenesis in the mandible, reversing radiation therapy–induced isotropy and creating a robust vascular network. Bone marrow stromal cells may offer clinicians an alternative reconstructive modality that could improve the lifestyle of patients with hypovascular bone. PMID:25415276
Sil, Soumitri; Dahlquist, Lynnda M; Thompson, Caitlin; Hahn, Amy; Herbert, Linda; Wohlheiter, Karen; Horn, Susan
This study sought to evaluate the effectiveness of virtual reality (VR) enhanced interactive videogame distraction for children undergoing experimentally induced cold pressor pain and examined the role of avoidant and approach coping style as a moderator of VR distraction effectiveness. Sixty-two children (6-13 years old) underwent a baseline cold pressor trial followed by two cold pressor trials in which interactive videogame distraction was delivered both with and without a VR helmet in counterbalanced order. As predicted, children demonstrated significant improvement in pain tolerance during both interactive videogame distraction conditions. However, a differential response to videogame distraction with or without the enhancement of VR technology was not found. Children's coping style did not moderate their response to distraction. Rather, interactive videogame distraction with and without VR technology was equally effective for children who utilized avoidant or approach coping styles.
Aronson, J; Harrison, B H; Stewart, C L; Harp, J H
The local biology of distraction osteogenesis using Ilizarov and Wagner external fixators was compared in unilateral tibial lengthenings in two groups of eight dogs. Serial roentgenograms with histological correlation revealed some basic similarities as well as distinct differences between the two groups. All dogs fully bridged the experimental gap by intramembranous ossification. Subtle histological changes in the alignment of collagen bundles and subsequent ossification reflected the mechanical configuration of each fixator. The multiplanar, full-pin Ilizarov system delivered concentric load to the site of osteogenesis, inducing perfectly parallel columns of new bone. The uniplanar, one-half pin Wagner system induced angulation of the collagen and subsequent bone columns on the basis of eccentric load to the osteogenic interface. Despite a significant difference in axial rigidity, the Ilizarov and Wagner external fixators induced osteogenesis of equal volume.
Zhao, Danyang; Wang, Yu
The treatment of bone defects is challenging and controversial. As a new technology, periosteal distraction osteogenesis (PDO) uses the osteogenicity of periosteum, which creates an artificial space between the bone surface and periosteum to generate new bone by gradually expanding the periosteum with no need for corticotomy. Using the newly formed bone of PDO to treat bone defects is effective, which can not only avoid the occurrence of immune-related complications, but also solve the problem of insufficient donor. This review elucidates the availability of PDO in the aspects of mechanisms, devices, strategies, and measures. Moreover, we also focus on the future prospects of PDO and hope that PDO will be applied to the clinical treatment of bone defects in the future. PMID:28078283
Brand-D'Abrescia, Muriele; Lavie, Nilli
Load theory predictions for the effects of task coordination between and within sensory modalities (vision and hearing or vision only) on the level of distraction were tested. Response competition effects in a visual flanker task when it was coordinated with an auditory discrimination task (between-modality conditions) or a visual discrimination task (within-modality conditions) were compared with single-task conditions. In the between-modality conditions, response competition effects were greater in the two- (vs. single-) task conditions irrespective of the level of discrimination task difficulty. In the within-modality conditions, response competition effects were greater in the two-task (vs. single-task) conditions only when these involved a more difficult visual discrimination task. The results provided support for the load theory prediction that executive control load leads to greater distractor interference while highlighting the effects of task modality.
McNab, Fiona; Zeidman, Peter; Rutledge, Robb B; Smittenaar, Peter; Brown, Harriet R; Adams, Rick A; Dolan, Raymond J
A weakened ability to effectively resist distraction is a potential basis for reduced working memory capacity (WMC) associated with healthy aging. Exploiting data from 29,631 users of a smartphone game, we show that, as age increases, working memory (WM) performance is compromised more by distractors presented during WM maintenance than distractors presented during encoding. However, with increasing age, the ability to exclude distraction at encoding is a better predictor of WMC in the absence of distraction. A significantly greater contribution of distractor filtering at encoding represents a potential compensation for reduced WMC in older age.
Nord, P G
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.
Dobbs, Thomas D; Wall, Steven A; Richards, Peter G; Johnson, David
Distraction osteogenesis (DO) has revolutionised the treatment of mid-face hypoplasia in children, allowing advancement of the mid-face in excess of that achievable by traditional Le Fort III osteotomy. One method of performing DO is to use an externally applied frame, such as the Rigid External Distraction (RED) frame. However, at young ages the cranial bone is often too weak to support the frame, preventing its safe use. We present the case of a patient with Crouzon syndrome who required mid-face distraction at 4-months of age due to severe exorbitism, raised intracranial pressure and airway compromise. In order to allow safe application of an external distraction frame laminated bone grafts were secured to the cranium at the areas of frame pin insertion. We believe this to be the first reported case of the use of the patients own cranial bone to create laminated bone grafts and thicken the site of pin insertion. The method described adds to the armamentarium of the surgeon treating these patients who require placement of an external distraction frame for DO at a young age where the thickness of the cranial bone may otherwise prevent safe application.
Crespo Del Hierro, Jorge; Ruiz González, Manuel; Delgado Portela, Margarita; García Del Castillo, Eduardo; Crespo Serrano, Juan
Sinusitis of dental origin is a relatively frequent entity, but the presence of an odontoma in the sinus as a source of this pathology is exceptional. Here we present a case of a young patient who presented chronic maxillary sinusitis over 2 years, originating in an odontoma located in the sinus drainage area.
Semaan, Steven; Goonewardene, Mithran S
An optimal outcome of combined surgery and orthodontics involving the maxilla is dependent on many factors. Accurate placement of the maxilla by the surgical team is ultimately of paramount importance. The aim of this retrospective study was to evaluate the accuracy of LeFort I maxillary osteotomy with respect to the presurgical prediction. The sample comprised 42 patients (33 females, nine males) who had undergone LeFort I osteotomy procedure alone or in combination with a mandibular osteotomy with or without genioplasty. Tracings of presurgical and immediate postsurgical lateral cephalograms and surgical predictions were digitized and compared using Quick Ceph software analysis. Vertical and horizontal measurements to various skeletal landmarks were used to assess the discrepancy between the predicted maxillary position and the actual postsurgical result. Statistically significant differences were found between the predicted and actual postsurgical maxillary molar vertical position, and significant differences were also found for the palatal plane angular measurements. Two surgical teams were compared, and surgical team 1 had significantly less variation in the surgical outcomes than did surgical team 2. When single-jaw and bimaxillary surgery were compared, no significant differences were found. Similarly, there were no statistically significant differences found when assessing the primary direction of movement (impaction vs downgraft vs advancement). Overall, 66% of the results were within two mm of prediction and 26% of the results were within one mm of prediction. A LeFort I maxillary osteotomy can be an accurate procedure with a wide range of discrepancy.
Macaluso, P J
The purpose of the present investigation was to assess the potential usefulness of permanent maxillary molar cusp diameters for sex discrimination of poorly preserved skeletal remains. Cusp diameters were measured from standardized occlusal view photographs in a sample of black South Africans consisting of 130 males and 105 females. Results demonstrated that all cusp dimensions for both first and second maxillary molars exhibited significant sexual dimorphism (p < 0.001). Univariate and multivariate discriminant function equations permitted low to moderate classification accuracy in discriminating sex (58.3%-73.6%). The allocation accuracies for cusp diameter measurements were as high as, and even surpassed, those observed for conventional crown length and breadth dimensions of the same teeth. The most accurate result (73.6%, with a sex bias of only 0.5%) was obtained when all cusp diameters from both maxillary molars were used concurrently. However, only slightly less accurate results (~70.0%) were achieved when selected dimensions from only one of the molars, or even a single cusp, were utilized. Although not as reliable at predicting sex as other skeletal elements in black South Africans, the derived odontometric standards can be used with highly fragmentary skeletal material, as well as immature remains in which crown formation of the maxillary molars is complete.
Arisu, Hacer Deniz; Alacam, Tayfun
Anatomical variations must be considered in clinical and radiographical evaluations during endodontic treatment. Access cavity modifications may be required for stress free entry to complex anatomy. Higher magnification and illumination can be useful for access cavity preparation and to recognize and locate additional canals. This article describes the diagnosis and clinical management of two clinical cases of three rooted maxillary premolars. PMID:19262733
Matiakin, E G; Chuchkov, V M; Akhundov, A A; Azizian, R I; Romanov, I S; Chuchkov, M V; Agapov, V V
Speech quality was evaluated in 188 patients with acquired maxillary defects. Prosthetic treatment of 29 patients was preceded by pharmacopsychotherapy. Sixty three patients had lessons with a logopedist and 66 practiced self-tuition based on the specially developed test. Thirty patients were examined for the quality of speech without preliminary preparation. Speech quality was assessed by auditory and spectral analysis. The main forms of impaired speech quality in the patients with maxillary defects were marked rhinophonia and impaired articulation. The proposed analytical tests were based on a combination of "difficult" vowels and consonants. The use of a removable prostheses with an obturator failed to correct the affected speech function but created prerequisites for the formation of the correct speech stereotype. Results of the study suggest the relationship between the quality of speech in subjects with maxillary defects and their intellectual faculties as well as the desire to overcome this drawback. The proposed tests are designed to activate the neuromuscular apparatus responsible for the generation of the speech. Lessons with a speech therapist give a powerful emotional incentive to the patients and promote their efforts toward restoration of speaking ability. Pharmacopsychotherapy and self-control are another efficacious tools for the improvement of speech quality in patients with maxillary defects.
Cansiz, Erol; Akbas, Emine; Isler, Sabri Cemil
Surgically assisted rapid palatal expansion (SARPE) is one of the most common orthognathic surgery operations for the treatment of maxillary transverse deficiencies. Although this operation is considered technically simple and has low complication rate, predisposing factors can complicate the postoperative period. In this case report, fistula formation and aspergillosis after SARPE operation were presented. PMID:28163491
Debnath, Subhas Chandra; Adhyapok, Apurba Kumar; Hazarika, Kriti; Malik, Kapil; Vatsyayan, Ashutosh
Aneurysmal bone cyst (ABC) is a nonneoplastic rare pathologic entity of the jaws. Its locally aggressive nature and high recurrence rate after curettage make surgical resection a better treatment option. Here, we present a case of ABC of maxillary alveolus and its management by alveolectomy followed by white head varnish pack application in the surgical defect. PMID:27041915
Pinheiro, Fábio Henrique de Sá Leitão; Garib, Daniela Gamba; Janson, Guilherme; Bombonatti, Roberto; de Freitas, Marcos Roberto
OBJECTIVE: The aim of this retrospective study was to compare the longitudinal stability of two types of posterior crossbite correction: rapid maxillary expansion (RME) and slow maxillary expansion (SME). METHODS: Study casts of 90 adolescent patients were assessed for interdental width changes at three different periods: pretreatment (T1), post-treatment (T2) and at least, five years post-retention (T3). Three groups of 30 patients were established according to the treatment received to correct posterior crossbite: Group A (RME), group B (SME) and group C (control- Edgewise therapy only). After crossbite correction, all patients received fixed edgewise orthodontic appliances. Paired t-tests and one-way ANOVA were used to identify significant intra and intergroup changes, respectively (P < 0.05). RESULTS: Except for intercanine distance, all widths increased in groups A and B from T1 to T2. In the long-term, the amount of relapse was not different for groups A and B, except for 3-3 widths which showed greater decrease in group A. However, the percentage of clinically relapsed cases of posterior crossbite was similar for rapid and slow maxillary expansion. CONCLUSION: Rapid and slow maxillary expansion showed similar stability in the long-term. PMID:25628082
Liang, Rui-Zhen; Wu, Jin-Tao; Wu, You-Nong; Smales, Roger J; Hu, Ming; Yu, Jin-Hua; Zhang, Guang-Dong
This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months. PMID:23222992
Dargaud, J; Cotton, F; Buttin, R; Morin, A
The maxillary sinus, or Highmore's antrum, is located in the maxillary bone. The maxillary, above the buccal cavity, below the orbital cavity and outside the nasal fossa, is going to take a part in the formation of the three cavities which surround it. Although voluminous, it is consists of a light bone. This distinctive feature is essentially due to the fact that the maxillary has a cavity. The maxillary sinus occupies the upper 2/3s of this maxillary bone. It is the largest of the facial structure's cavities. Its volume is very variable, depending on the individual, the condition of their edentulousness and their age. We find small, average or large sinuses. This sinus communicates with the corresponding nasal fossa by a canal. It opens at the level of the nasofrontalis duct by a meatic ostium, an ostium located at the top of the meatus nasi medius, i.e. under the floor of the sinus. This highly positioned drainage location easily explains the problems that sinus pathologies can come up against. The sinus is lined with a mucous membrane and we can point out that in the normal condition this mucous membrane adheres weakly to the bone. It is more or less thick as a function of the pathologies to which the sinus has been subjected, or even as a function of the geographical location where the individual lives. The imaging of this sinus as a function of age is not obvious due to the fact that it is invisible throughout embryonic and foetal development, and that it only becomes visible to X-rays relatively late, at about 6 years old. Its role is important at the level of the growth of the facial structure because it is always easier to have growth around cavities. It also has a mechanical role concerning the transmission of shockwaves during traumas. In old individuals, due to the condition of the edentulousness, the volume of the sinus is larger; in fact one can note the resorption of the alveolar bone. The maxillary sinus is a cavity which plays a very important role
Shireen, Ayesha; Ara, Syeda Arshiya
Aims: This study was conducted to assess the sex determination potential from mesiodistal (MD) and buccolingual (BL) dimensions of permanent maxillary first molar. Subjects and Methods: The study was conducted in the Department of Oral Medicine and Radiology, Al-Badar Rural Dental College and Hospital, Gulbarga, Karnataka, on 600 subjects (300 male and 300 female), aged 17–25 years. The subjects were selected based on the inclusion and exclusion criteria set forth for the study. After obtaining informed consent, the intraoral measurements of MD and BL dimensions on casts of the first maxillary molars were taken using digital vernier caliper with resolution of 0.01 mm. Statistical Analysis Used: The data obtained were subjected to statistical analysis using paired and unpaired t-test to compare MD and BL dimensions between males and females. P ≤0.05 was considered statistically significant. Results: The mean MD width of the first maxillary molar was 10.60 ± 0.6644 mm (right) and 10.60 ± 0.6644 mm (left) in males and 10.40 ± 0.6255 mm (right) and 10.40 ± 0.6255 mm (left) in females. The mean BL width of the first maxillary molar was 11.60 ± 1.2227 mm (right) and 11.60 ± 1.2227 mm (left) in males and 11.20 ± 0.8440 mm (right) and 11.20 ± 0.8440 mm (left) in females. The differences between males and females in MD and BL dimensions measured were statistically significant (P < 0.05). Right and left MD dimensions exhibited sexual dimorphism of 1.92% and right and left BL dimensions exhibited sexual dimorphism of 3.57%. Conclusions: The MD and BL dimensions of the maxillary first molars may be used as an aid in sex discrimination. PMID:28123268
Finlayson, Nonie J; Remington, Roger W; Retell, James D; Grove, Philip M
In visual search, target detection times are relatively insensitive to set size when targets and distractors differ on a single feature dimension. Search can be confined to only those elements sharing a single feature, such as color (Egeth, Virzi, & Garbart, 1984). These findings have been taken as evidence that elementary feature dimensions support a parallel segmentation of a scene into discrete sets of items. Here we explored if relative depth (signaled by binocular disparity) could support a similar parallel segmentation by examining the effects of distributing distracting elements across two depth planes. Three important empirical findings emerged. First, when the target was a feature singleton on the target depth plane, but a conjunction search among distractors on the nontarget plane, search efficiency increased compared to a single depth plane. Second, benefits of segmentation in depth were only observed when the target depth plane was known in advance. Third, no benefit of segmentation in depth was observed when both planes required a conjunction search, even with prior knowledge of the target depth plane. Overall, the benefit of distributing the elements of a search set across two depth planes was observed only when the two planes differed both in binocular disparity and in the elementary feature composition of individual elements. We conclude that segmentation of the search array into two depth planes can facilitate visual search, but unlike color or other elementary properties, does not provide an automatic, preattentive segmentation.
Piper, Merisa L; Delrosario, Lawrence; Hoffman, William Y
Acquired thoracic dystrophy is a complication associated with early open repair of pectus excavatum resulting from extensive cartilage resection. The condition can cause serious functional and physiologic impairments, including cardiac compression and restrictive pulmonary function. We describe a 17-year-old boy with acquired thoracic dystrophy after Ravitch repair of pectus excavatum during infancy, whom we treated with distraction osteogenesis. The patient had a marked deformity of the chest wall and general hypoplasia of the central portion of the ribcage, with resultant symptomatic dyspnea on exertion and reduced pulmonary function. After osteotomies and distraction osteogenesis of bilateral ribs 4-8 using customized distraction devices, he had improved thoracic contour, resolution of dyspnea, and decreased restrictive pulmonary symptoms. This case suggests that distraction osteogenesis, already used extensively in craniomaxillofacial and orthopedic surgery, may be a novel method for management of this condition.
Mohammed-Ali, Ricardo I; Henry, Alastair M; Khurram, Syed A; Yousefpour, Afshin
We report a case of plate-guided distraction osteogenesis to reconstruct a large mandibular defect caused by recurrence of an ameloblastoma in a 17-year-old male patient who had previously had reconstruction using a fibula bone graft.
Fuente del Campo, A
In this paper, the author describes the distraction devise designed and developed by the author to perform the procedure of inducted bone generation or "bone distraction". The characteristics, principles, and advantages of this device are also described in comparison with other more expensive devices. The author's clinic experience using this device: 126 patients with a maximum follow-up of 54/12 years and an average bone distraction of 31 mm. The procedure was done on patients from 8/12 to 38 years of age. Bone distraction is a good option for early reconstruction of craniofacial skeletal defects, eliminating the need for bone grafts, maxillo-mandibular fixation, and other more aggressive and complex procedures. The results obtained with this distractor show that it is a stable, precise, and useful device. Its low cost and the simplicity of the technique make it very accessible to every surgeon with some experience in bone surgery and craniofacial or othognatic surgery.
Kelley, Patrick; Mata, Carlos; Da Silveira, Adriana
Melnick-Needles syndrome is a congenital syndrome associated with severe architectural disorder of the skeletal system that can cause significant effects on the craniofacial skeleton including the mandible and temporomandibular joint. We report on a case of a young adult patient who experienced chronic dislocation, pain, and dysfunction of her temporomandibular joints related to both a severe bite dysfunction (mandibular hypoplasia) and the underlying bony architectural disorder associated with Melnick-Needles syndrome. The patient underwent bilateral mandibular distraction to correct her skeletal malocclusion and improve the condylar relationship with the temporomandibular joint fossae. The inherent bony abnormalities presented unique challenges to distraction. The patient was successfully distracted using internal mandibular distractors, rhBMP-2, and a prolonged distraction protocol. The patient experienced complete resolution of symptoms and resumed an unrestricted diet 6 months after removal of devices and has been pain-free for more than 24 months.
Yu, Hongbo; Dai, Jiewen; Wang, Xudong; Zhang, Wenbin; Shen, Steve Guofang
Patients with nasomaxillary hypoplasia have severe facial concavity and compromised skeletal class III malocclusion. Its treatment is still a challenge to surgeons. Our aim was to evaluate the combination of midfacial distraction and orthognathic surgery in the treatment of nasomaxillary hypoplasia. Four patients with nasomaxillary hypoplasia were enrolled in this study. After Le Fort II osteotomy, the rotational distraction of nasomaxillary complex was performed to rehabilitate facial convexity. Then bilateral sagittal split ramus osteotomy with or without Le Fort I osteotomy was used to correct malocclusion. All patients healed uneventfully, and the maxillae moved forward conspicuously. No obvious pain and severe discomfort were complained during distraction. A significant advancement and downward movement of the maxilla were shown by cephalometric analysis. The combination of midfacial distraction and orthognathic surgery provides us an ideal alternative in the treatment of nasomaxillary hypoplasia.
Pérez Cervera, T; Lirola Criado, J F; Farrington Rueda, D M
The growing rod technique is currently one of the most common procedures used in the management of early onset scoliosis. However, in order to preserve spine growth and control the deformity it requires frequent surgeries to distract the rods. Magnetically driven growing rods have recently been introduced with same treatment goal, but without the inconvenience of repeated surgical distractions. One of the limitations of this technical advance is an increase in radiation exposure due to the increase in distraction frequency compared to conventional growing rods. An improvement of the original technique is presented, proposing a solution to the inconvenience of multiple radiation exposure using ultrasound technology to control the distraction process of magnetically driven growing rods.
Brinkschulte, Markus; Bienert-Zeit, Astrid; Lüpke, Matthias; Hellige, Maren; Staszyk, Carsten; Ohnesorge, Bernhard
The system of the paranasal sinuses morphologically represents one of the most complex parts of the equine body. A clear understanding of spatial relationships is needed for correct diagnosis and treatment. The purpose of this study was to describe the anatomy and volume of equine paranasal sinuses using three-dimensional (3D) reformatted renderings of computed tomography (CT) slices. Heads of 18 cadaver horses, aged 2-25 years, were analyzed by the use of separate semi-automated segmentation of the following bilateral paranasal sinus compartments: rostral maxillary sinus (Sinus maxillaris rostralis), ventral conchal sinus (Sinus conchae ventralis), caudal maxillary sinus (Sinus maxillaris caudalis), dorsal conchal sinus (Sinus conchae dorsalis), frontal sinus (Sinus frontalis), sphenopalatine sinus (Sinus sphenopalatinus), and middle conchal sinus (Sinus conchae mediae). Reconstructed structures were displayed separately, grouped, or altogether as transparent or solid elements to visualize individual paranasal sinus morphology. The paranasal sinuses appeared to be divided into two systems by the maxillary septum (Septum sinuum maxillarium). The first or rostral system included the rostral maxillary and ventral conchal sinus. The second or caudal system included the caudal maxillary, dorsal conchal, frontal, sphenopalatine, and middle conchal sinuses. These two systems overlapped and were interlocked due to the oblique orientation of the maxillary septum. Total volumes of the paranasal sinuses ranged from 911.50 to 1502.00 ml (mean ± SD, 1151.00 ± 186.30 ml). 3D renderings of equine paranasal sinuses by use of semi-automated segmentation of CT-datasets improved understanding of this anatomically challenging region.
Medved, Mario; Truyen, Roel; Likar, Bostjan; Pernus, Franjo
Segmentation of colon CT images is the main factor that inhibits automation of virtual colonoscopy. There are two main reasons that make efficient colon segmentation difficult. First, besides the colon, the small bowel, lungs, and stomach are also gas-filled organs in the abdomen. Second, peristalsis or residual feces often obstruct the colon, so that it consists of multiple gas-filled segments. In virtual colonoscopy, it is very useful to automatically connect the centerlines of these segments into a single colon centerline. Unfortunately, in some cases this is a difficult task. In this study a novel method for automated colon segmentation and connection of colon segments' centerlines is proposed. The method successfully combines features of segments, such as centerline and thickness, with information on main colon segments. The results on twenty colon cases show that the method performs well in cases of small obstructions of the colon. Larger obstructions are mostly also resolved properly, especially if they do not appear in the sigmoid part of the colon. Obstructions in the sigmoid part of the colon sometimes cause improper classification of the small bowel segments. If a segment is too small, it is classified as the small bowel segment. However, such misclassifications have little impact on colon analysis.
Gliklich, Emily; Guo, Rong; Bergmark, Regan W
Texting and other cell-phone related distracted driving is estimated to account for thousands of motor vehicle collisions each year but studies examining the specific cell phone reading and writing activities of drivers are limited. The objective of this study was to describe the frequency of cell-phone related distracted driving behaviors. A national, representative, anonymous panel of 1211 United States drivers was recruited in 2015 to complete the Distracted Driving Survey (DDS), an 11-item validated questionnaire examining cell phone reading and writing activities and at what speeds they occur. Higher DDS scores reflect more distraction. DDS scores were analyzed by demographic data and self-reported crash rate. Nearly 60% of respondents reported a cell phone reading or writing activity within the prior 30 days, with reading texts (48%), writing texts (33%) and viewing maps (43%) most frequently reported. Only 4.9% of respondents had enrolled in a program aimed at reducing cell phone related distracted driving. DDS scores were significantly correlated to crash rate (p < 0.0001), with every one point increase associated with an additional 7% risk of a crash (p < 0.0001). DDS scores were inversely correlated to age (p < 0.0001). The DDS demonstrated high internal consistency (Cronbach's alpha = 0.94). High rates of cell phone-related distraction are reported here in a national sample. Distraction is associated with crash rates and occurs across all age groups, but is highest in younger drivers. The DDS can be used to evaluate the impact of public health programs aimed at reducing cell-phone related distracted driving.
Smoski, Moria J.; LaBar, Kevin S.; Steffens, David C.
Objectives The present study compares the effectiveness of two strategies, reappraisal and distraction, in reducing negative affect in older adults induced by focusing on personally relevant negative events and stressors. Participants included 30 adults with MDD and 40 never-depressed (ND) comparison participants ages 60 and over (mean age = 69.7 years). Design and Measurements Participants underwent three affect induction trials, each followed by a different emotion regulation strategy: distraction, reappraisal, and a no-instruction control condition. Self-reported affect was recorded pre- and post-affect induction, and at one-minute intervals during regulation. Results Across groups, participants reported greater reductions in negative affect with distraction than reappraisal or the no-instruction control condition. An interaction between group and regulation condition indicated that distraction was more effective in reducing negative affect in the MDD group than the ND group. Conclusions These results suggest that distraction is an especially effective strategy for reducing negative affect in older adults with MDD. Finding ways to incorporate distraction skills into psychotherapeutic interventions for late-life MDD may improve their effectiveness, especially for short-term improvement of affect following rumination. PMID:24021222
Dosch, Alessandra; Ghisletta, Paolo; Van der Linden, Martial
This study explored the link between body image and desire to engage in sexual activity (dyadic and solitary desire) in adult women living in a long-term couple relationship. Moreover, it considered two psychological factors that may underlie such a link: the occurrence of body-related distracting thoughts during sexual activity and encoding style (i.e., the tendency to rely on preexisting internal schemata versus external information at encoding). A total of 53 women (29 to 47 years old) in heterosexual relationships completed questionnaires assessing sexual desire (dyadic, solitary), body image, body-related distracting thoughts during sexual activity, and encoding style. Results showed that poor body image was associated with low dyadic and solitary sexual desire. Body-related distracting thoughts during sexual activity mediated the link between body image and solitary (but not dyadic) sexual desire. Finally, the mediation of body-related distracting thoughts between body image and solitary sexual desire was moderated by encoding style. A negative body image promoted the occurrence of body-related distracting thoughts during sexual activity, especially in internal encoders. Our study highlights the importance of body image, distracting thoughts, and encoding style in women's solitary sexuality and suggests possible factors that may reduce the impact of those body-related factors in dyadic sexual desire.
Wightman, Frederic L.; Kistler, Doris J.
Using a closed-set speech recognition paradigm thought to be heavily influenced by informational masking, auditory selective attention was measured in 38 children (ages 4-16 years) and 8 adults (ages 20-30 years). The task required attention to a monaural target speech message that was presented with a time-synchronized distracter message in the same ear. In some conditions a second distracter message or a speech-shaped noise was presented to the other ear. Compared to adults, children required higher target/distracter ratios to reach comparable performance levels, reflecting more informational masking in these listeners. Informational masking in most conditions was confirmed by the fact that a large proportion of the errors made by the listeners were contained in the distracter message(s). There was a monotonic age effect, such that even the children in the oldest age group (13.6-16 years) demonstrated poorer performance than adults. For both children and adults, presentation of an additional distracter in the contralateral ear significantly reduced performance, even when the distracter messages were produced by a talker of different sex than the target talker. The results are consistent with earlier reports from pure-tone masking studies that informational masking effects are much larger in children than in adults.
Van Dyke, Nicholas A.; Fillmore, Mark T.
Rationale Research indicates that alcohol intoxication and increased demands on drivers’ attention from distractions (e.g. passengers and cell phones) contribute to poor driving performance and increased rates of traffic accidents and fatalities. Objectives The present study examined the separate and combined effects of alcohol and distraction on simulated driving performance at blood alcohol concentrations (BrACs) below the legal driving limit in the United States (i.e. 0.08%). Methods Fifty healthy adult drivers (36 men and 14 women) were tested in a driving simulator following a 0.65 g/kg dose of alcohol and a placebo. Drivers completed two drive tests; a distracted drive, which included a two-choice detection task, and an undistracted control drive. Multiple indicators of driving performance, such as drive speed, within-lane deviation, steering rate, and lane exceedances were measured. Results Alcohol and distraction each impaired measures of driving performance. Moreover, the magnitude of alcohol impairment was increased by at least two-fold when tested under the distracting versus the undistracted condition. Conclusions The findings highlight the need for a clearer understanding of how common distractions impact intoxicated drivers, especially at BrACs that are currently legal for driving in the United States. PMID:26349918
Stimpson, Jim P.
Objectives. We examined trends in distracted driving fatalities and their relation to cell phone use and texting volume. Methods. The Fatality Analysis Reporting System (FARS) records data on all road fatalities that occurred on public roads in the United States from 1999 to 2008. We studied trends in distracted driving fatalities, driver and crash characteristics, and trends in cell phone use and texting volume. We used multivariate regression analysis to estimate the relation between state-level distracted driving fatalities and texting volumes. Results. After declining from 1999 to 2005, fatalities from distracted driving increased 28% after 2005, rising from 4572 fatalities to 5870 in 2008. Crashes increasingly involved male drivers driving alone in collisions with roadside obstructions in urban areas. By use of multivariate analyses, we predicted that increasing texting volumes resulted in more than 16 000 additional road fatalities from 2001 to 2007. Conclusions. Distracted driving is a growing public safety hazard. Specifically, the dramatic rise in texting volume since 2005 appeared to be contributing to an alarming rise in distracted driving fatalities. Legislation enacting texting bans should be paired with effective enforcement to deter drivers from using cell phones while driving. PMID:20864709
Gabbay, Joubin S; Zuk, Patricia A; Tahernia, Amir; Askari, Morad; O'Hara, Catherine M; Karthikeyan, Tharun; Azari, Kodi; Hollinger, Jeffery O; Bradley, James P
Osteoblast biology is influenced in vivo by a 3-dimensional (3D) extracellular matrix that mediates their adhesion and interaction and by a constant state of compressive and tensile forces. To study the role of mechanical stress on osteoblasts in vitro, these parameters must be addressed. Therefore, this study describes the use of a novel, in vitro system that subjects cells to distractive and compressive forces in a 3D environment. This system, termed a microdistractor system, was used to apply linear forces to 3D collagen type I gels containing preosteoblasts. Gels were induced for up to 16 days in osteogenic medium and subjected to either constant linear distraction (distraction gels) or to repeating cycles of distraction and compression (oscillation gels). The effect of these stresses was evaluated over time by measuring proliferation rates, protein synthesis (i.e., cellular activity), and osteogenic differentiation levels. While linear forces in general appeared to increase protein synthesis, force-specific effects on proliferation and differentiation were observed. Specifically, distraction forces appeared to enhance MC3T3 proliferation while distraction/compressive forces appeared to accelerate their osteogenic differentiation program. Therefore, these results suggest that the microdistraction system may be an appropriate in vitro system for the study of mechanobiology in osteoblast phenotype.
Park, Jong-Tae; Lee, Jae-Gi; Kim, Soo-Yeon; Kim, Gyu-Hag; Hu, Kyung-Seok; Cha, Jung-Yul; Kim, Hyung Jun; Kim, Hee-Jin
Distraction osteogenesis is widely applied to correct oral and maxillofacial deformities, and intermittent distraction protocols have been used in various clinical applications. There are many challenges for continuous distraction of the jaw bone such as when using hydraulic motors and motor-driven plates. The size of the motor is critical to the ability to miniaturize the complete distractor system, and the importance of size makes it difficult to extrapolate the results of animal models to the clinical situation. This study developed a microactuator-generated distractor (MAGD) for continuous jaw bone distraction. The MAGD system consists of control software based on Microsoft Windows and a Squiggle piezoelectric motor. The system allows various intermittent and continuous distraction protocols to be simply selected using the control software. The maximum force of the laboratory-scale MAGD is 3 N, and the device is ready for adoption in small-animal distraction models such as the rat and mouse. The MAGD needs further refinement before it can be applied to humans, but a fully implanted MAGD system will reduce soft-tissue complications resulting from exposure of the extraoral component. Moreover, the MAGD will support the patient's social activities and require only minimal cooperation from the patient.
Smith, Wally; Pearce, Jon; Borland, Ron
Background Despite considerable effort, most smokers relapse within a few months after quitting due to cigarette craving. The widespread adoption of mobile phones presents new opportunities to provide support during attempts to quit. Objective To design and pilot a mobile app "DistractMe" to enable quitters to access and share distractions and tips to cope with cigarette cravings. Methods A qualitative study with 14 smokers who used DistractMe on their mobiles during the first weeks of their quit attempt. Based on interviews, diaries, and log data, we examined how the app supported quitting strategies. Results Three distinct techniques of coping when using DistractMe were identified: diversion, avoidance, and displacement. We further identified three forms of engagement with tips for coping: preparation, fortification, and confrontation. Overall, strategies to prevent cravings and their effects (avoidance, displacement, preparation, and fortification) were more common than immediate coping strategies (diversion and confrontation). Tips for coping were more commonly used than distractions to cope with cravings, because they helped to fortify the quit attempt and provided opportunities to connect with other users of the application. However, distractions were important to attract new users and to facilitate content sharing. Conclusions Based on the qualitative results, we recommend that mobile phone-based interventions focus on tips shared by peers and frequent content updates. Apps also require testing with larger groups of users to assess whether they can be self-sustaining. PMID:25099632
Atchley, Paul; Hadlock, Chelsie; Lane, Sean
Successful campaigns to end distracted driving must understand prevailing social norms for behaviors such as texting and phoning while driving. The current work examined this issue by asking younger drivers to read car crash scenarios and rate the responsibility of the driver for the crash, and to levy fines and assign jail time, as a function of whether the driver was attentive, had been drinking, or was distracted by phoning or texting. In the first experiment, ratings were performed in the absence of injunctive norm information (laws against drunk and distracted driving). In the second experiment, injunctive norm information was included. Impaired drivers were viewed as more responsible in both experiments, with texting drivers viewed as the most responsible. However, drunk drivers received the most fines and jail time. When compared to data from the 1970s, the results show that anti-drunk driving campaigns have changed how younger drivers view drunk driving, but that norms have not yet changed for distracted driving, despite consistent results showing they know the risk of driving distracted. Implications for social norm distracted driving campaigns are discussed.
Wang, Lei; Zhou, Shuxia; Liu, Baolin; Lei, Delin; Zhao, Yinghua; Lu, Chao; Tan, Aixing
Distraction osteogenesis is widely used in treating deformities, defects, and fractures of both long bones and craniofacial bones. Demands for acceleration of bone consolidation are increased in distraction osteogenesis. Nerve growth factor (NGF) can enhance innervation and bone regeneration in a fracture model and stimulate differentiation of osteoblastic cells. In this study, we tested the ability of locally applied NGF to enhance bone regeneration in a rabbit model of mandibular distraction osteogenesis. Twenty rabbits underwent bilateral distraction osteogenesis with a rate of 0.5 mm per 12 h. Two times 0.04 mg human NGFbeta (hNGFbeta) in buffer was injected into the callus after distraction. The contralateral side received placebo injections. Rabbits were euthanized at consolidation times of 14 and 28 days. Specimens were subjected to radiography, callus dimensions measurement, mechanical testing, and bone histological and histomorphometric analysis. The maximum load, bone volume/total volume, mineral apposition rate of the 1st to 11th day, and mineralized bone percentage were significantly higher in the hNGFbeta side at 14 and 28 days (p<0.05). The data indicate that locally applied hNGFbeta can accelerate callus maturation and may be an option to shorten the consolidation period in distraction osteogenesis.
Shao, Heng; Shu, Hengsheng; Wang, Chunmei; Yuan, Wu; Li, Yunsheng
Despite many experimental and clinical studies conducted on distraction osteogenesis (DO) in the past decade, changes in the surrounding tissues that occur after the procedure remains poorly understood. To study the biochemical changes of recovery in nerve tissues upon DO-induced nerve injury, we prepared a rabbit model of tibia lengthening to observe the expression pattern of nerve growth factor (NGF) and low-affinity NGF receptor (p75NGFR) in the distracted tibial nerve. The distracted tibial nerve was harvested at various time points during the consolidation period of new bone formation and immunohistochemical staining was performed to detect the expression of NGF and p75NGFR. The expression levels of NGF and p75NGFR were found to be different at various times after DO. The changes in expression of these two cellular factors show similar tendencies with significantly elevated expression in Schwann cells at 7 and 14 days after distraction, but low or undetectable levels of expression at 0, 28, and 56 days. These results suggest that NGF and p75NGFR may play important roles in the adaptive process of the distracted nerve. NGF and p75NGFR are autocrine growth factors present in the distracted nerve during the early consolidation period. NGF interacts with p75NGFR to promote damage repair and reconstruction of nerves. Together, this study furthers the understanding of the relative mechanisms of nerve repair, as well as provides a further basis for the clinical application of neurotrophins.
Dahal, Nabaraj; (Nanda Nandagopal, D.; Cocks, Bernadine; Vijayalakshmi, Ramasamy; Dasari, Naga; Gaertner, Paul
Objective. The objective of our current study was to look for the EEG correlates that can reveal the engaged state of the brain while undertaking cognitive tasks. Specifically, we aimed to identify EEG features that could detect audio distraction during simulated driving. Approach. Time varying autoregressive (TVAR) analysis using Kalman smoother was carried out on short time epochs of EEG data collected from participants as they undertook two simulated driving tasks. TVAR coefficients were then used to construct all pole model enabling the identification of EEG features that could differentiate normal driving from audio distracted driving. Main results. Pole analysis of the TVAR model led to the visualization of event related synchronization/desynchronization (ERS/ERD) patterns in the form of pole displacements in pole plots of the temporal EEG channels in the z plane enabling the differentiation of the two driving conditions. ERS in the EEG data has been demonstrated during audio distraction as an associated phenomenon. Significance. Visualizing the ERD/ERS phenomenon in terms of pole displacement is a novel approach. Although ERS/ERD has previously been demonstrated as reliable when applied to motor related tasks, it is believed to be the first time that it has been applied to investigate human cognitive phenomena such as attention and distraction. Results confirmed that distracted/non-distracted driving states can be identified using this approach supporting its applicability to cognition research.
Max, Caroline; Widmann, Andreas; Schröger, Erich; Sussman, Elyse
This study tested effects of task requirements and knowledge on auditory distraction effects. This was done by comparing the response to a pitch change (an irrelevant, distracting tone feature) that occurred predictably in a tone sequence (every 5th tone) under different task conditions. The same regular sound sequence was presented with task conditions varying in what information the participant was given about the predictability of the pitch change, and when this information was relevant for the task to be performed. In all conditions, participants performed a tone duration judgment task. Behavioral and event-related brain potential (ERP) measures were obtained to measure distraction effects and deviance detection. Predictable deviants produced behavioral distraction effects in all conditions. However, the P3a amplitude evoked by the predictable pitch change was largest when participants were uninformed about the regular structure of the sound sequence, showing an effect of knowledge on involuntary orienting of attention. In contrast, the mismatch negativity (MMN) component was only modulated when the regularity was relevant for the task and not by stimulus predictability itself. P3a and behavioral indices of distraction were not fully concordant. Overall, our results show differential effects of knowledge and predictability on auditory distraction effects indexed by neurophysiological (P3a) and behavioral measures.
Oei, Nicole Y L; Veer, Ilya M; Wolf, Oliver T; Spinhoven, Philip; Rombouts, Serge A R B; Elzinga, Bernet M
Acute stress has been shown to impair working memory (WM), and to decrease prefrontal activation during WM in healthy humans. Stress also enhances amygdala responses towards emotional stimuli. Stress might thus be specifically detrimental to WM when one is distracted by emotional stimuli. Usually, emotional stimuli presented as distracters in a WM task slow down performance, while evoking more activation in ventral 'affective' brain areas, and a relative deactivation in dorsal 'executive' areas. We hypothesized that after acute social stress, this reciprocal dorsal-ventral pattern would be shifted towards greater increase of ventral 'affective' activation during emotional distraction, while impairing WM performance. To investigate this, 34 healthy men, randomly assigned to a social stress or control condition, performed a Sternberg WM task with emotional and neutral distracters inside an MRI scanner. Results showed that WM performance after stress tended to be slower during emotional distraction. Brain activations during emotional distraction was enhanced in ventral affective areas, while dorsal executive areas tended to show less deactivation after stress. These results suggest that acute stress shifts priority towards processing of emotionally significant stimuli, at the cost of WM performance.
Adams, Zachary W.; Roberts, Walter M.; Milich, Richard; Fillmore, Mark T.
Increased intra-individual variability in response time (RTSD) has been observed reliably in ADHD and is often used as a measure of inattention. RTSD is assumed to reflect attentional lapses and distractibility, though evidence for the validity of this connection is lacking. We assessed whether RTSD is an indicator of inattention by comparing RTSD on the stop-signal task (SST) to performance on the Delayed Oculomotor Response (DOR) Task, a measure of distractibility. Participants included 30 adults with ADHD and 28 controls. Participants completed the SST and the DOR task, which measured subjects’ ability to maintain attention and avoid distraction by inhibiting reflexive saccades toward distractors. On the SST, the ADHD group was slower to inhibit than controls, indicating poorer inhibitory control in ADHD. The ADHD group also displayed slower RTs, greater RTSD, and more omission errors. On the DOR task, the ADHD group displayed more premature saccades (i.e., greater distractibility) than controls. Greater variability in RT was associated with increased distraction on the DOR task but only in ADHD participants. Results suggest that RTSD is linked to distractibility among adults with ADHD and support the use of RTSD as a valid measure of inattention in ADHD. PMID:21443365
Ruette, Peter; Lammens, Johan
This study was conducted to assess the safety of humeral lengthening using an Ilizarov frame. We retrospectively reviewed 26 humeral segments in 17 patients that were lengthened at our department between 1993 and 2011. There were varying aetiologies including achondroplasia, epiphyseal dysplasia, Oilier disease, trauma or infection of the proximal humeral growth-plate, unicameral bone cyst and brachial plexus injury. Mean age at start of surgery was 17.05 years (range : 5-40). The mean lengthening achieved was 8.85 (3-13) cm. Mean lengthening percentage was 353% (range : 10-48). Average healing index was 30.56 days/cm (range : 17.46-4232). There was a significant difference in healing index between achondroplasia patients (28.79 days/cm) compared to others (33.41 days/cm). Minor problems included pin tract infection (14 segments). More important obstacles were temporary elbow flexion contracture (7 segments), premature consolidation (6 segments), radial nerve dysaesthesia (6 segments) and loosening of a Schanz screw (1 segment). Complications included one fracture and one progressive bowing after frame removal. One planned lengthening was not completely achieved. Despite a lot of obstacles, humeral lengthening using an Ilizarov frame provided a reliable method to treat the functional or cosmetic problems of upper limb shortening.
The Drosophila maxillary palpus that develops during metamorphosis is composed of two elements: the proximal maxillary socket and distal maxillary palp. The HOX protein, Proboscipedia (PB), was required for development of the proximal maxillary socket and distal maxillary palp. For growth and differentiation of the distal maxillary palp, PB was required in the cells of, or close to, the maxillary socket, as well as the cells of the distal maxillary palp. Therefore, PB is required in cells outside the distal maxillary palp for the expression, by some mechanism, of a growth factor or factors that promote the growth of the distal maxillary palp. Both wingless (wg) and hedgehog (hh) genes were expressed in cells outside the distal maxillary palp in the lancinia and maxillary socket, respectively. Both wg and hh were required for distal maxillary palp growth, and hh was required noncell autonomously for distal maxillary palp growth. However, expression of wg-GAL4 and hh-GAL4 during maxillary palp differentiation did not require PB, ruling out a direct role for PB in the regulation of transcription of these growth factors. PMID:28357140
Song, Sang-Heon; Agashe, Mandar; Kim, Tae-Young; Sinha, Shivam; Park, Young-Eun; Kim, Seung-Ju; Hong, Jin-Ho; Song, Sang-Youn; Song, Hae-Ryong
Distraction osteogenesis is one of the common procedures for limb lengthening. However, attempts are being made constantly to establish objective guidelines for early and safe removal of a fixator using a sensitive and quantitative measurement technique. Dual-energy X-ray absorptiometry (DEXA) has been evaluated in the past for understanding callus stiffness, and the present study is a step further in this direction. The purpose of this study was to evaluate the correlation between bone mineral density ratio (BMDR) obtained by a DEXA scan and the pixel value ratio (PVR) on plain digital radiographs at each cortex and various callus pathways and callus shapes as described by Ru-Li's classification. A retrospective analysis of 40 tibial segments in 23 patients operated upon for various indications for limb lengthening was carried out. There were 11 male and 12 female patients with a mean age of 18 years. The Ilizarov method was applied after monofocal osteotomy, and distraction and consolidation were monitored using digital radiographs and DEXA scanning. BMDR was positively correlated with PVR, and the optimal BMDR for removal of the fixator was found to be 0.511. PVR of all cortices, except the anterior cortex, showed significant positive correlation with BMDR of the regenerate. There was good correlation between BMDR and PVR in the homogenous or heterogenous pathway according to callus shape and pathway. Thus, this study shows that BMD measurement can provide an objective and noninvasive method for assessing the rate of new bone formation during tibial distraction osteogenesis. It can thus function as an effective adjunct to measure callus stiffness, along with PVR, using digital radiographs, especially in cases in which callus maturation and stiffness is doubtful. Further studies especially dealing with callus progression through the lucent pathway as well as those dealing with regenerate fractures may be needed to conclusively prove the efficacy of this method
Tanaka, Eiji; Nishi-Sasaki, Akiko; Hasegawa, Takuro; Nishio, Clarice; Kawai, Nobuhiko; Tanne, Kazuo
The correction of a severe maxillary protrusion in an adult by distal movement of the maxillary molars has been one of the most difficult biomechanical problems in orthodontics. This article reports on the treatment of an adult case of severe maxillary protrusion and a large overjet treated with a skeletal anchorage system. A female patient, age 22 years and 3 months, complained of the difficulty of lip closure due to severe maxillary protrusion with a gummy smile. Overjet and overbite were +7.6 mm and -0.9 mm, respectively. She had a history of orthodontic treatment in which her maxillary first premolars were extracted. In order to conduct distal movement of the maxillary molars, anchor plates were placed in the zygomatic process. After achieving a Class I molar relationship, retraction and intrusion of the maxillary incisors were performed. After a 2-year treatment, an acceptable occlusion was achieved with a Class I molar relationship. Her convex facial profile with upper lip protrusion was considerably improved, and the lips showed less tension in lip closure. After a 2-year retention period, an acceptable occlusion was maintained without recurrence of maxillary protrusion, indicating a stability of the occlusion. The result of this treatment indicated that skeletal anchorage is of great importance as a remedy for achieving intrusion and retraction of the maxillary incisors in cases of severe maxillary protrusion with a patient who had previous orthodontic treatment.
Hernández, Mireia; Costa, Albert; Humphreys, Glyn W
We ask whether bilingualism aids cognitive control over the inadvertent guidance of visual attention from working memory and from bottom-up cueing. We compare highly-proficient Catalan-Spanish bilinguals with Spanish monolinguals in three visual search conditions. In the working memory (WM) condition, attention was driven in a top-down fashion by irrelevant objects held in WM. In the Identify condition, attention was driven in a bottom-up fashion by visual priming. In the Singleton condition, attention was driven in a bottom-up fashion by including a unique distracting object in the search array. The results showed that bilinguals were overall faster than monolinguals in the three conditions, replicating previous findings that bilinguals can be more efficient than monolinguals in the deployment of attention. Interestingly, bilinguals were less captured by irrelevant information held in WM but were equally affected by visual priming and unique singletons in the search displays. These observations suggest that bilingualism aids top-down WM-mediated guidance of attention, facilitating processes that keep separate representations in WM from representations that guide visual attention. In contrast, bottom-up attentional capture by salient yet unrelated input operates similarly in bilinguals and monolinguals.
Gudavalli, M. R.; Potluri, T.; Carandang, G.; Havey, R. M.; Voronov, L. I.; Cox, J. M.; Rowell, R. M.; Kruse, R. A.; Joachim, G. C.; Patwardhan, A. G.; Henderson, C. N. R.; Goertz, C.
The objective of this study was to measure intradiscal pressure (IDP) changes in the lower cervical spine during a manual cervical distraction (MCD) procedure. Incisions were made anteriorly, and pressure transducers were inserted into each nucleus at lower cervical discs. Four skilled doctors of chiropractic (DCs) performed MCD procedure on nine specimens in prone position with contacts at C5 or at C6 vertebrae with the headpiece in different positions. IDP changes, traction forces, and manually applied posterior-to-anterior forces were analyzed using descriptive statistics. IDP decreases were observed during MCD procedure at all lower cervical levels C4-C5, C5-C6, and C6-C7. The mean IDP decreases were as high as 168.7 KPa. Mean traction forces were as high as 119.2 N. Posterior-to-anterior forces applied during manual traction were as high as 82.6 N. Intraclinician reliability for IDP decrease was high for all four DCs. While two DCs had high intraclinician reliability for applied traction force, the other two DCs demonstrated only moderate reliability. IDP decreases were greatest during moving flexion and traction. They were progressevely less pronouced with neutral traction, fixed flexion and traction, and generalized traction. PMID:24023587
Chan, Michelle; Madan, Christopher R; Singhal, Anthony
Roadside billboards containing negative and positive emotional content have been shown to influence driving performance, however, the impact of highly arousing taboo information is unknown. Taboo information more reliably evokes emotional arousal and can lead to greater attentional capture due to its inherent 'shock value.' The objective of the present study was to examine driver distraction associated with four types of information presented on roadside billboards: highly arousing taboo words, moderately arousing positive and negative words, and non-arousing neutral words. Participants viewed blocks of taboo, positive, negative and neutral words presented on roadside billboards while operating a driving simulator. They also responded to target (household-related) words by pressing a button on the steering wheel. At the end of the session, a surprise recall task was completed for all the words they saw while driving. Results showed that taboo words captured the most attention as revealed by better memory recall compared to all the other word types. Interestingly, taboo words were associated with better lane control compared to the other word types. We suggest that taboo-related arousal can enhance attentional focus during a complex task like simulated driving. That is, in a highly arousing situation, attention is selectively narrowed to the road ahead, resulting in better lane control.
Cheung, Stephen S; Westwood, David A; Knox, Matthew K
Many contemporary workers are routinely exposed to mild cold stress, which may compromise mental function and lead to accidents. A study investigated the effect of mild body cooling of 1.0 degree C rectal temperature (Tre) on vigilance (i.e. sustained attention) and the orienting of spatial attention (i.e. spatially selective processing of visual information). Vigilance and spatial attention tests were administered to 14 healthy males and six females at four stages (pre-immersion, deltaTre = 0, -0.5 and - 1.0 degree C ) of a gradual, head-out immersion cooling session (18-25 deltaC water), and in four time-matched stages of a contrast session, in which participants sat in an empty tub and no cooling took place. In the spatial attention test, target discrimination times were similar for all stages of the contrast session, but increased significantly in the cooling phase upon immersion (deltaTre = 0 degrees C), with no further increases at deltaTre = -0.5 and - 1.0 degree C. Despite global response slowing, cooling did not affect the normal pattern of spatial orienting. In the vigilance test, the variability of detection time was adversely affected in the cooling but not the contrast trials: variability increased at immersion but did not increase further with additional cooling. These findings suggest that attentional impairments are more closely linked to the distracting effects of cold skin temperature than decreases in body core temperature.
Pezze, M A; Marshall, H J; Cassaday, H J
Trace conditioning procedures are defined by the introduction of a trace interval between conditioned stimulus (CS, e.g. noise or light) offset and unconditioned stimulus (US, e.g. footshock). The introduction of an additional stimulus as a distractor has been suggested to increase the attentional demands of the task and to extend the usefulness of the behavioural model. In Experiment 1, the CS was noise and the distractor was provided by an intermittent light. In Experiment 2, the CS was light and the distractor was provided by an intermittent noise. In both experiments, the introduction of a 10s trace interval weakened associative learning compared with that seen in a 0s delay conditioned group. However, there was no consistent evidence of distraction. On the contrary, in Experiment 1, associative learning was stronger (in both trace and delay conditioned groups) for rats conditioned also in the presence of the intermittent light. In Experiment 2, there was no such effect when the roles of the stimuli were reversed. The results of Experiment 2 did however confirm the particular salience of the noise stimulus. The finding of increased associative learning dependent on salience is consistent with arousal-mediated effects on associative learning.
Salo, Emma; Salmela, Viljami; Salmi, Juha; Numminen, Jussi; Alho, Kimmo
Top-down controlled selective or divided attention to sounds and visual objects, as well as bottom-up triggered attention to auditory and visual distractors, has been widely investigated. However, no study has systematically compared brain activations related to all these types of attention. To this end, we used functional magnetic resonance imaging (fMRI) to measure brain activity in participants performing a tone pitch or a foveal grating orientation discrimination task, or both, distracted by novel sounds not sharing frequencies with the tones or by extrafoveal visual textures. To force focusing of attention to tones or gratings, or both, task difficulty was kept constantly high with an adaptive staircase method. A whole brain analysis of variance (ANOVA) revealed fronto-parietal attention networks for both selective auditory and visual attention. A subsequent conjunction analysis indicated partial overlaps of these networks. However, like some previous studies, the present results also suggest segregation of prefrontal areas involved in the control of auditory and visual attention. The ANOVA also suggested, and another conjunction analysis confirmed, an additional activity enhancement in the left middle frontal gyrus related to divided attention supporting the role of this area in top-down integration of dual task performance. Distractors expectedly disrupted task performance. However, contrary to our expectations, activations specifically related to the distractors were found only in the auditory and visual cortices. This suggests gating of the distractors from further processing perhaps due to strictly focused attention in the current demanding discrimination tasks.
Crundall, David; Van Loon, Editha; Underwood, Geoffrey
The optimum positioning of roadside advertisements is recognized by the industry as an important factor in attracting the attention of passing drivers. Less acknowledged is the possibility that the location of an advertisement may distract attention from vital driving-related information. This study compared street-level advertisements (SLAs; predominantly bus shelters) with raised-level advertisements (RLAs) of the same size that were suspended 3 m above the ground, on their ability to attract attention under different task conditions. Participants were split into two groups and watched video clips of driving, rating them for hazardousness while their eye movements were recorded. One of the groups was additionally primed to attend to advertisements. SLAs received the most fixations when participants were solely looking for hazards, and the fewest fixations when primed to look for advertisements. Though SLAs also had longer fixations than the RLAs, they were more poorly recognized in a subsequent memory test. We conclude that SLAs attract and hold attention at inappropriate times compared to raised-level advertisements.
Wang, Yu-Kai; Jung, Tzyy-Ping; Lin, Chin-Teng
Distracted driving might lead to many catastrophic consequences. Developing a countermeasure to track drivers' focus of attention (FOA) and engagement of operators in dual (multi)-tasking conditions is thus imperative. Ten healthy volunteers participated in a dual-task experiment that comprised two tasks: a lane-keeping driving task and a mathematical problem-solving task (e.g., 24+15=37?) during which their electroencephalogram (EEG) and behaviors were concurrently recorded. Independent component analysis (ICA) was employed as a spatial filter to separate the contributions of independent sources from the recorded EEG data. The power spectra of six components (i.e., frontal, central, parietal, occipital, left motor, and right motor) extracted from single-task conditions were fed into support vector machine (SVM) based on the radial basis function (RBF) kernel to build an FOA assessment system. The system achieved 84.6±5.8% and 86.2±5.4% classification accuracies in detecting the participants' FOAs on the math versus driving tasks, respectively. This FOA assessment system was then applied to evaluate participants' FOAs during dual-task conditions. The detected FOAs revealed that participants' cognitive attention and strategies dynamically changed between tasks to optimize the overall performance, as attention was limited and competed. The empirical results of this study demonstrate the feasibility of a practical system to continuously estimating cognitive attention through EEG spectra.
Brandl, Stephanie; Frølich, Laura; Höhne, Johannes; Müller, Klaus-Robert; Samek, Wojciech
Objective. While motor-imagery based brain-computer interfaces (BCIs) have been studied over many years by now, most of these studies have taken place in controlled lab settings. Bringing BCI technology into everyday life is still one of the main challenges in this field of research. Approach. This paper systematically investigates BCI performance under 6 types of distractions that mimic out-of-lab environments. Main results. We report results of 16 participants and show that the performance of the standard common spatial patterns (CSP) + regularized linear discriminant analysis classification pipeline drops significantly in this ‘simulated’ out-of-lab setting. We then investigate three methods for improving the performance: (1) artifact removal, (2) ensemble classification, and (3) a 2-step classification approach. While artifact removal does not enhance the BCI performance significantly, both ensemble classification and the 2-step classification combined with CSP significantly improve the performance compared to the standard procedure. Significance. Systematically analyzing out-of-lab scenarios is crucial when bringing BCI into everyday life. Algorithms must be adapted to overcome nonstationary environments in order to tackle real-world challenges.
Gudavalli, M R; Potluri, T; Carandang, G; Havey, R M; Voronov, L I; Cox, J M; Rowell, R M; Kruse, R A; Joachim, G C; Patwardhan, A G; Henderson, C N R; Goertz, C
The objective of this study was to measure intradiscal pressure (IDP) changes in the lower cervical spine during a manual cervical distraction (MCD) procedure. Incisions were made anteriorly, and pressure transducers were inserted into each nucleus at lower cervical discs. Four skilled doctors of chiropractic (DCs) performed MCD procedure on nine specimens in prone position with contacts at C5 or at C6 vertebrae with the headpiece in different positions. IDP changes, traction forces, and manually applied posterior-to-anterior forces were analyzed using descriptive statistics. IDP decreases were observed during MCD procedure at all lower cervical levels C4-C5, C5-C6, and C6-C7. The mean IDP decreases were as high as 168.7 KPa. Mean traction forces were as high as 119.2 N. Posterior-to-anterior forces applied during manual traction were as high as 82.6 N. Intraclinician reliability for IDP decrease was high for all four DCs. While two DCs had high intraclinician reliability for applied traction force, the other two DCs demonstrated only moderate reliability. IDP decreases were greatest during moving flexion and traction. They were progressevely less pronouced with neutral traction, fixed flexion and traction, and generalized traction.
Barbaro, Roberto; Troisi, Donato; D’Alessio, Giuseppe; Amato, Maurizio; Lo Giudice, Roberto; Paolo Claudio, Pier
Abstract Modern concepts in the world of beauty arise from popular models, beautiful faces of actors document a bi-protrusive asset with high tension for soft tissues. Facial symmetry has been proposed as a marker of development and stability that may be important in human mate choice. For various traits any deviation from perfect symmetry can be considered a reflection of imperfect development. Additionally, bi-protrusive profile is dependent on the hormonal level regardless of male or female sex. The goal of maxillofacial surgery is to provide best results both for aesthetic and functional aspects. Following these new concepts of aesthetic of the face, new surgical procedure by osteodistraction techniques will lead to a very natural result by harmonizing the face also preventing aesthetic decay in aging faces. Ten cases with a feedback on the aesthetic results using the fivepoint scale of Likert after orthognatic surgery performed following distraction new techniques in combination with ancillary surgical procedures. The aesthetic results in all patients were highly satisfactory. All the patients accepted the new aesthetic of the face avoiding elements of discrepancy and consequently medico-legal problems. PMID:28352833
Amir, Lisa R; Becking, Alfred G; Jovanovic, Andreas; Perdijk, Frits B T; Everts, Vincent; Bronckers, Antonius L J J
We examined the effect of distraction rate on blood vessel growth in intramembraneous ossification after vertical distraction osteogenesis in the human mandible. Six edentulous patients (aged 60+/-9 years) with a severely atrophic mandible underwent bone augmentation with distraction osteogenesis. Two distraction rates (0.5 and 1 mm/day) were compared and for each group three patients were analyzed. Vascular histomorphometry was carried out in two different areas in the distraction gap: (1) in the first and (2) in the second 1 mm area from the osteotomy line, representing the oldest and younger new-bone area, respectively. Correlation analysis was performed between blood vessel parameters and the amount of new bone formed during distraction. Histological analysis demonstrated the presence of blood vessels throughout the soft connective tissue in the distraction gap. The volume density of blood vessels between the two investigated areas was significantly lower in the 1 mm/day groups, suggesting a delay in angiogenesis in this group of patients. A positive correlation between blood vessel volume and bone volume density was found in the younger new-bone area but not in the oldest new-bone area. This correlation was due to a higher number of blood vessels rather than to a larger size of the blood vessels. Our data suggest that the lower blood vessel density found in the patients with 1 mm/day distraction rate may be related to disruption of angiogenesis in the soft connective tissue of the gap or to a less optimal mechanical stimulation of cells involved in angiogenesis. This probably results in the slower rate of osteogenesis seen at the 1 mm/day distraction rate compared with the 0.5 mm/day distraction rate. The data support the concept that a positive relationship exists between the density of blood vessels and the formation of bone. For distraction of the human mandible in elderly patients, a distraction rate of 0.5 mm/day seems beneficial.
Snela, S; Kisiel, J; Gregosiewicz, A; Dziubiński, F
The magnitude of the distractive forces occurring in the Ilizarov and Orthofix apparatuses during limb lengthening by distractive osteogenesis has been investigated. Eighteen patients treated between 1995 and 1998 were included in the study. The data obtained were computerized and related to clinical, radiographic and sonographic findings. Typical and repeatable graphs of forces were found during the process of lengthening as well as typical relationships between the callus and the values of distractive forces.
Mahdavi, Omid; Boostani, Najmehalsadat; Karimi, Sharareh; Tabesh, Adel
Sinonasal undifferentiated carcinoma is an extremely rare malignancy of the paranasal sinuses and nasal cavity. It is of unknown etiology, and occurs more commonly in the elderly men, with a routinely shown aggressive behavior and poor prognosis for survival. Radiographically, it looks like severe osteomyelitis. Histopathologic study is essential to confirm diagnosis, and the undifferentiated histologic appearance often necessitates immunohistochemical studies for differentiation from other high-grade neoplasms. We present an 83-year-old man complaining of pain and unilateral swelling on the left side of the face due to a rare malignant tumor of maxillary sinus origin, a sinonasal undifferentiated carcinoma. He underwent hemimaxillectomy and radiotherapy, but refused chemotherapy. Maxillary sinus malignancy may be presented with unspecific symptoms mimicking sinusitis or dental pain. Coming across such symptoms, the physician or dentist must consider malignancies as well, and carry out medical and dental workups. PMID:24910668
Kasamatsu, Atsushi; Kimura, Yasushi; Tsujimura, Hideki; Kanazawa, Harusachi; Koide, Nao; Miyamoto, Isao; Endo-Sakamoto, Yosuke; Shiiba, Masashi; Tanzawa, Hideki; Uzawa, Katsuhiro
Multiple myeloma is a malignant neoplasm of plasma cells characterized by proliferation of a single clone of abnormal immunoglobulin-secreting plasma cells. Since the amount of hemopoietic bone marrow is decreased in the maxilla, oral manifestations of multiple myeloma are less common in the maxilla than in the mandible. We report the case of 33-year-old Japanese man who presented with a mass in the right maxillary alveolar region. Computed tomography and magnetic resonance images showed a soft tissue mass in the right maxilla eroding the anterior and lateral walls of the maxillary sinus and extending into the buccal space. The biopsy results, imaging, and laboratory investigations led to the diagnosis of multiple myeloma. This case report suggests that oral surgeons and dentists should properly address oral manifestations as first indications of multiple myeloma. PMID:26640721
Choi, Kyung-Hee; Lee, Yoonjung; Kim, Minji
This article describes the orthodontic treatment of a 25-year-old Korean female patient with anterior crowding, including palatally displaced lateral incisors. Her facial profile was satisfactory, but 3.5 mm of maxillary anterior crowding was observed. To correct this crowding, we decided to minimize the use of the conventional fixed orthodontic appliances and employed a less bulky and more aesthetic appliance for applying light continuous force. We determined the final positions of the maxillary teeth via a working model for diagnostic set up and achieved space gaining and alignment with simple Ni-Ti spring and stainless steel round tubes. Tooth alignment was achieved efficiently and aesthetically without the conventional brackets. PMID:24015390
Lehman, J A; Haas, A J
A conservative osteotomy of the zygomaticomaxillary buttress in combination with a rapid palatal expansion appliance is a dependable technique for the treatment of horizontal maxillary deficiency in adults. This procedure has been used successfully in 56 patients in our series, but 17 patients (30 percent) required a midpalatal osteotomy. In two patients, overexpansion was not achieved because of necrosis of the mucosa. In three other patients, expansion had to proceed at a slower pace because of mucosal ulceration. There have been no other complications. The procedure is indicated mainly in those patients with a horizontal deficiency who do not require subsequent surgery, but for some patients it may be the preliminary procedure. Twelve patients (21 per cent) had subsequent orthognathic surgery. Follow-up has been from 1 to 12 years and there has been no relapse. In our opinion, the zygomaticomaxillary buttress is the primary area of resistance to lateral movement of the maxilla by rapid maxillary expansion appliances.
Lehman, J A; Haas, A J
A conservative osteotomy of the zygomaticomaxillary buttress in combination with a rapid palatal expansion appliance is a dependable technique for the treatment of horizontal maxillary deficiency in adults. This procedure has been used successfully in 56 patients in our series, but 17 patients (30 per cent) required a midpalatal osteotomy. In two patients, overexpansion was not achieved because of necrosis of the mucosa. In three other patients, expansion had to proceed at a slower pace because of mucosal ulceration. There have been no other complications. The procedure is indicated mainly in those patients with a horizontal deficiency who do not require subsequent surgery, but for some patients it may be the preliminary procedure. Twelve patients (21 per cent) had subsequent orthognathic surgery. Follow-up has been from 1 to 12 years and there has been no relapse. In our opinion, the zygomaticomaxillary buttress is the primary area of resistance to lateral movement of the maxilla by rapid maxillary expansion appliances.
Lehman, J A; Haas, A J; Haas, D G
Osteotomy of the zygomaticomaxillary buttress in combination with a rapid palatal exapnsion appliance is a dependable technique for the treatment of horizontal maxillary deficiency in adults. This procedure has been used in 18 patients with excellent expansion in 17. In one patient, expansion was discontinued prior to overcorrection because of pressure necrosis on the palate related to the appliance. This was the only complication. The procedure is indicated mainly in those patients with a horizontal deficiency who do not require subsequent surgery, but for some patients it may be the preliminary procedure. Three patients in this series had subsequent orthognathic surgery. Follow-up has been from 1 to 6 years, and there has been no relapse. In our opinion, the zygomaticomaxillary buttress is the primary area of resistance to lateral movement of the maxilla by rapid maxillary expansion appliances.
Sekerci, Ahmet-Ercan; Köse, Emre; Sisman, Yildiray
Background This study assessed the relationship between mucosal thickness (MT) of the maxillary sinus and periodontal bone loss (PBL) and periapical condition of related teeth. We also aimed to identify the association between root apices and the inferior wall of the maxillary sinus using Cone beam computed tomography (CBCT). Material and Methods In this study, CBCT images of 205 patients with 410 maxillary sinuses were examined, retrospectively. A total of 582 maxillary molars and 587 premolars were observed. The relationship of each root with maxillary sinus and apical lesions of these roots were classified, PBL was examined and the situations of adjacent teeth were estimated. The effect of these conditions on sinus mucosal thickness (MT) was evaluated. Results There was a significant correlation between MT of maxillary sinus and both PBL and age (r = 0.52, p=0.000 and r = 0.111, p= 0.002, respectively). The frequency of MT increased as the severity of apical lesion enlarged. A positive correlation was found between MT and degree of PBL and periapical lesions. To reveal the association between MT and pulpoperiapical condition bivariate correlation was done and a significant relationship between the pulpoperiapical condition and MT was found (r = 0.17, p=0.000). Conclusions This retrospective study showed that MT of the maxillary sinus was common among patients with PBL and MT was significantly associated with PBL and apical lesions. The relationship of maxillary sinus to adjacent teeth had also positive correlation with MT. CBCT imaging enabled better evaluation of maxillary sinus, posterior teeth and surrounding structures compared to other imaging tools. Key words:Maxillary sinus mucosal thickness, apical periodontitis, periodontal bone loss, CBCT. PMID:26241459
Yadav, Rakesh Kumar; Tikku, Aseem Prakash; Chandra, Anil; Mehta, Shibha
Esthetic and functional impairment due to dental trauma is a major concern for patients. The management of such traumatic cases is complex, and it requires a comprehensive knowledge, diagnosis, and treatment planning. It is also important to take into account the patient's desire as well as economical status. The present case report describes a simple, conservative, and noninvasive approach for the rehabilitation of traumatized maxillary incisors. PMID:28356699
Vijayaraghavan, N. Vasantha; Ramesh, Ganesh; Thareja, Amit; Patil, Seema
The effect of oral cancer with its therapeutic intervention involves significant facial and functional disabilities. It is customary to rehabilitate these patients by surgical or prosthetic means. Studies have been done to assess mastication and other functions after rehabilitation. A review of these studies for assessing masticatory function has been done under separate sections for maxillary and mandibular defects. Different masticatory tests are mentioned. Further scope for research has been highlighted. PMID:26392731
A 21-yr-old female suffering from osteogenesis imperfecta was anesthetized for correction of maxillary and mandibular deformities that had restricted her chewing. Preoperative assessment revealed a difficult intubation, restrictive lung disease secondary to bony deformities, and multiple repairs of fractures. Management of anesthesia for this operation--which is very rarely carried out in this disorder--is described along with a review of the problems of anesthesia associated with osteogenesis imperfecta. PMID:8934957
In this author's opinion, the advent of mini implants, or small diameter implants (SDIs) as they are more frequently being called, are becoming in many situations a viable alternative to the more traditional root form implants. They offer advantages of less cost, a more simplified placement technique, usually faster healing times, and generally less post-operative complications. A case presentation is given to demonstrate their usage for a narrow ridge application to restore congenitally missing maxillary lateral incisors.
In this author's opinion, the advent of mini implants, or small diameter implants (SDIs) as they are more frequently being called, is becoming in many situations a viable alternative to the more traditional root form implants. They offer advantages of less cost, a more simplified placement technique, usually faster healing times, and generally less post-operative complications. A case presentation is given to demonstrate their usage for a narrow ridge application to restore congenitally missing maxillary lateral incisors.
Saulacic, Nikola; Nakahara, Ken; Iizuka, Tateyuki; Haga-Tsujimura, Maiko; Hofstetter, Willy; Scolozzi, Paolo
The regenerative pathways during periosteal distraction osteogenesis may be influenced by the local environment composed by cells, growth factors, nutrition and mechanical load. The aim of the present study was to evaluate the influence of two protocols of periosteal distraction on bone formation. Custom made distraction devices were surgically fixed onto the calvariae of 60 rabbits. After an initial healing period of 7 days, two groups of animals were submitted to distraction rates of 0.25 and 0.5 mm/24 h for 10 days, respectively. Six animals per group were sacrificed 10 (mid-distraction), 17 (end-distraction), 24 (1-week consolidation), 31 (2-week consolidation) and 77 days (2-month consolidation) after surgery. Newly formed bone was assessed by means of micro-CT and histologically. Expression of transcripts encoding tissue-specific genes (BMP-2, RUNX2, ACP5, SPARC, collagen I α1, collagen II α1 and SOX9) was analyzed by quantitative PCR. Two patterns of bone formation were observed, originating from the old bone surface in Group I and from the periosteum in Group II. Bone volume (BV) and bone mineral density (BMD) significantly increased up to the 2-month consolidation period within the groups (p < 0.05). Significantly more bone was observed in Group II compared to Group I at the 2-month consolidation period (p < 0.001). Expression of transcripts encoding osteogenic genes in bone depended on the time-point of observation (p < 0.05). Low level of transcripts reveals an indirect role of periosteum in the osteogenic process. Two protocols of periosteal distraction in the present model resulted in moderate differences in terms of bone formation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1121-1131, 2016.
Parmentier, Fabrice B R
Numerous studies have demonstrated that rare and unexpected changes in an otherwise repetitive or structured sound sequence ineluctably break through selective attention and impact negatively on performance in an unrelated task. While the electrophysiological responses to unexpected sounds have been extensively studied, behavioral distraction has received relatively less attention until recently. In this paper, I review work examining the cognitive underpinnings of behavioral distraction by deviant sounds and highlight some of its key determinants. Evidence indicates that deviance distraction (1) derives from the time penalty associated with the involuntary orientation of attention to and away from the deviant sound and from resulting effects such as the reactivation of the relevant task set upon the presentation of the target stimulus; and (2) is mediated by a number of factors (some increasing distraction, such as aging or induced emotions; some decreasing it, such as a memory load or cognitive control). Contrary to the received view that deviants ineluctably elicit distraction, recent work demonstrates that it is contingent upon auditory distractors acting as unspecific warning signals in the service of goal-oriented behavior, and that deviants do not elicit distraction because they are rare but because they violate the cognitive system's predictions (which can be manipulated through implicit rule learning or explicit cueing). Evidence is also presented indicating that the capture of attention by spoken deviant sounds is followed by an involuntary evaluation of their semantic properties, the outcome of which can be robust enough to linger in working memory and interfere with subsequent behavior. Finally, I review studies suggesting that behavioral deviance distraction is not the mere byproduct of the mismatch negativity, P3a and re-orientation negativity electrophysiological responses and highlight a number of outstanding questions for future research.
Ilgenstein, Bernd; Deyhle, Hans; Jaquiery, Claude; Kunz, Christoph; Stalder, Anja; Stübinger, Stefan; Jundt, Gernot; Beckmann, Felix; Müller, Bert; Hieber, Simone E.
Bone augmentation is a vital part of surgical interventions of the oral and maxillofacial area including dental implantology. Prior to implant placement, sufficient bone volume is needed to reduce the risk of peri-implantitis. While augmentation using harvested autologous bone is still considered as gold standard, many surgeons prefer bone substitutes to reduce operation time and to avoid donor site morbidity. To assess the osteogenic efficacy of commercially available augmentation materials we analyzed drill cores extracted before implant insertion. In younger patients, distraction osteogenesis is successfully applied to correct craniofacial deformities through targeted bone formation. To study the influence of mesenchymal stem cells on bone regeneration during distraction osteogenesis, human mesenchymal stem cells were injected into the distraction gap of nude rat mandibles immediately after osteotomy. The distraction was performed over eleven days to reach a distraction gap of 6 mm. Both the rat mandibles and the drill cores were scanned using synchrotron radiation-based micro computed tomography. The three-dimensional data were manually registered and compared with corresponding two-dimensional histological sections to assess bone regeneration and its morphology. The analysis of the rat mandibles indicates that bone formation is enhanced by mesenchymal stem cells injected before distraction. The bone substitutes yielded a wide range of bone volume and degree of resorption. The volume fraction of the newly formed bone was determined to 34.4% in the computed tomography dataset for the augmentation material Geistlich Bio-Oss®. The combination of computed tomography and histology allowed a complementary assessment for both bone augmentation and distraction osteogenesis.
Malone, Laura A.
Control of the human walking pattern normally requires little thought, with conscious control used only in the face of a challenging environment or a perturbation. We have previously shown that people can adapt spatial and temporal aspects of walking to a sustained perturbation generated by a split-belt treadmill. Here we tested whether conscious correction of walking, versus distraction from it, modifies adaptation. Conscious correction of stepping may expedite the adaptive process and help to form a new walking pattern. However, because walking is normally an automatic process, it is possible that conscious effort could interfere with adaptation, whereas distraction might improve it by removing competing voluntary control. Three groups of subjects were studied: a control group was given no specific instructions, a conscious correction group was instructed how to step and given intermittent visual feedback of stepping during adaptation, and a distraction group performed a dual-task during adaptation. After adaptation, retention of aftereffects was assessed in all groups during normal treadmill walking without conscious effort, feedback, or distraction. We found that conscious correction speeds adaptation, whereas distraction slows it. Subjects trained with distraction retained aftereffects longest, suggesting that the training used during adaptation predicts the time course of deadaptation. An unexpected finding was that these manipulations affected the adaptation rate of spatial but not temporal elements of walking. Thus conscious processes can preferentially access the spatial walking pattern. It may be that spatial and temporal controls of locomotion are accessible through distinct neural circuits, with the former being most sensitive to conscious effort or distraction. PMID:20147417
McGehee, Daniel V.
Sources of distraction are numerous and varied, and defining and measuring distraction and attention is complicated. The driving task requires constant adjustments and reallocation of attention to cognitive, motor, and visual processes. While it is fairly straightforward to measure distraction in an experimental situation (e.g., simulator, closed course), driver distraction in the real world is highly contextual. While no single metric is capable of capturing the complexities of distraction, several have proved useful in helping researchers gain fuller understanding of it. Few have reached a level of consensus among researchers and user interface designers. ISO and SAE may be considered the ‘gold standard’ for providing mechanisms through which open scientific consensus-based standards can be achieved. While there are a number of metrics used in predicting distraction, three have been studied closely and are going through the SAE and ISO standards process. They are (1) ‘the occlusion method’; (2) the Lane Change Test (LCT); and (3) the Detection Response Task (DRT). The metrics described here apply generally to the experimental context where driving is tightly controlled. Like any method, there are limitations with each—and they don’t necessarily agree with one another. Experimental methods and analyses are different than those in naturalistic driving (ND). ND relies more on data mining versus traditional experimental manipulation. ND data are a challenge precisely in that they lack experimental control. In future, driver metrics will go beyond specific measurement of task load, and will include how drivers self regulate when they choose to be distracted. PMID:24776223
Cho, Sun-Mi; Choi, Sung-Hwan; Sung, Sang-Jin; Yu, Hyung-Seog
Objective The aim of this study was to determine the optimal loading conditions for pure intrusion of the six maxillary anterior teeth with miniscrews according to alveolar bone loss. Methods A three-dimensional finite element model was created for a segment of the six anterior teeth, and the positions of the miniscrews and hooks were varied after setting the alveolar bone loss to 0, 2, or 4 mm. Under 100 g of intrusive force, initial displacement of the individual teeth in three directions and the degree of labial tilting were measured. Results The degree of labial tilting increased with reduced alveolar bone height under the same load. When a miniscrew was inserted between the two central incisors, the amounts of medial-lateral and anterior-posterior displacement of the central incisor were significantly greater than in the other conditions. When the miniscrews were inserted distally to the canines and an intrusion force was applied distal to the lateral incisors, the degree of labial tilting and the amounts of displacement of the six anterior teeth were the lowest, and the maximum von Mises stress was distributed evenly across all the teeth, regardless of the bone loss. Conclusions Initial tooth displacement similar to pure intrusion of the six maxillary anterior teeth was induced when miniscrews were inserted distal to the maxillary canines and an intrusion force was applied distal to the lateral incisors. In this condition, the maximum von Mises stresses were relatively evenly distributed across all the teeth, regardless of the bone loss. PMID:27668194
Pourdanesh, F; Sharifi, R; Mohebbi, A; Jamilian, A
The effects of Le Fort I osteotomy on the nasal airway are controversial. This study aimed to evaluate nasal airway changes after Le Fort I. 25 patients underwent conventional Le Fort I osteotomy and were separated into three groups depending on the type of surgery they underwent. 11 patients needed maxillary impaction, 9 underwent maxillary advancement, and 5 had both maxillary impaction and advancement. Rhinological examinations, anterior rhinomanometry and acoustic rhinometry were carried out 1 week before surgery and 3 months after that. Wilcoxon and χ(2) tests were used for data analysis. The samples included 19 females and 6 males with a mean age of 22.4 ± 3.32 years. Rhinomanometric assessment showed that total nasal airflow was increased from 406 ± 202 ml/s to 543 ± 268 ml/s in all three groups. Significant decrease in nasal airway resistance was seen in all three groups. Acoustic rhinometry revealed a significant decrease in total nasal volume but an increase in the cross-sectional areas of isthmus nasi (IN) and inferior concha. The rhinomanometric measurements showed improvements in the total nasal airflow after Le Fort I osteotomy with alar base cinch suture in cases where the impaction was not higher than 5.5mm.
Perella, Andréia; Rocha, Sara Dos Santos; Cavalcanti, Marcelo de Gusmão Paraiso
The aim of this study was to evaluate the precision and accuracy of linear measurements of maxillary sinus made in tomographic films, by comparing with 3D reconstructed images. Linear measurements of both maxillary sinus in computed tomography CT of 17 patients, with or without lesion by two calibrated examiners independently, on two occasions, with a single manual caliper. A third examiner has done the same measurements electronically in 3D-CT reconstruction. The statistical analysis was performed using ANOVA (analyses of variance). Intra-observer percentage error was little in both cases, with and without lesion; it ranged from 1.14% to 1.82%. The inter-observer error was a little higher reaching a 2.08% value. The accuracy presented a higher value. The perceptual accuracy error was higher in samples, which had lesion compared to that which had not. CT had provided adequate precision and accuracy for maxillary sinus analyses. The precision in cases with lesion was considered inferior when compared to that without lesion, but it can't affect the method efficacy.
Amorim, Klinger de Souza; da Silva, Vanessa Tavares; da Cunha, Rafael Soares; Souto, Maria Luisa Silveira; São Mateus, Carla Rocha; Souza, Liane Maciel de Almeida
The maxillary sinus or antrum is the largest of the paranasal sinuses. It is located in the maxillary bone and has a proximity to the apexes of upper molars and premolars, which allows it to form a direct link between the sinus and the oral cavity. Dislocation of a foreign body or tooth to the interior of a paranasal sinus is a situation that can occur as a result of car accidents, firearm attacks, or iatrogenic in surgical procedures. Therefore, it is necessary to know how to treat this kind of situation. This study's objective is to report the case of a 23-year-old female patient, leucoderma, who sought treatment from the Surgical Unit at the Dental Faculty of the Federal University of Sergipe. She had a history of pain and edema in the right side of the genian region and two failed attempts at removing dental unit (DU) 18. The extraoral clinical exam revealed intense edema of the left hemiface with signs of infection, excoriation of the labial commissure, hematoma, a body temperature of 39°C, and a limited ability to open her mouth. The patient was medicated and treated surgically. The tooth was removed from the maxillary sinus with caution, as should have been done initially. PMID:25705524
Le Gall, Michel; Philippart-Rochaix, Martine; Philip-Alliez, Camille
Agenesis of the maxillary lateral incisors poses particular problems for dentists, orthodontists and patients. Treatment of these ageneses is still highly controversial, both functionally and esthetically. The patient's smile and anterior guidance are affected and must be restored. The diagnosis is easy. Few mistakes are possible. However, managing patients with missing maxillary lateral incisors can be a challenge, commonly involving two possible treatment approaches: space opening to replace the missing lateral incisor with a prosthetic unit (denture, bridge or implant) or orthodontic space closure replacing the missing lateral incisor with the maxillary canine camouflaged to mimic the appearance of a lateral incisor. One of these two options will be adopted using multiple means...liable to trigger a multitude of possible errors. Ultimately, optimal results can only be achieved if there is excellent coordination between different practitioners in various specialties. Each clinician will have a specific role to play. Also, the patient and family are at the heart of the decision-making process, by virtue of their consent (treatment duration, financial resources) and their motivation. This multi-factorial, multi-disciplinary decision process means that treatment of the lateral incisor is an ongoing challenge for the clinician striving for the best possible result. Each case is different. No set rules exist. No single factor can be neglected if we are to avoid "failure".
Bansal, Parul; Nikhil, Vineeta; Goyal, Ayush; Singh, Ritu
Traditional configuration of maxillary second premolars has been described to have two cusps, one root and one or two root canals. The endodontic literature reports considerable anatomic aberrations in the root canal morphology of maxillary second premolar but the literature available on the variation in cuspal anatomy and its relationship to the root canal anatomy is sparse. The purpose of this clinical report was to describe the root and root canal configuration of a maxillary second premolar with four cusps. PMID:27563190
Zhang, W B; Yu, Y; Wang, Y; Liu, X J; Mao, C; Guo, C B; Yu, G Y; Peng, X
The maxilla is the most important bony support of the mid-face skeleton and is critical for both esthetics and function. Maxillary defects, resulting from tumor resection, can cause severe functional and cosmetic deformities. Furthermore, maxillary reconstruction presents a great challenge for oral and maxillofacial surgeons. Nowadays, vascularized composite bone flap transfer has been widely used for functional maxillary reconstruction. In the last decade, we have performed a comprehensive research on functional maxillary reconstruction with free fibula flap and reported excellent functional and acceptable esthetic results. However, this experience based clinical procedure still remainssome problems in accuracy and efficiency. In recent years, computer assisted techniques are now widely used in oral and maxillofacial surgery. We have performed a series of study on maxillary reconstruction with computer assisted techniques. The computer assisted techniques used for maxillary reconstruction mainly include: (1) Three dimensional (3D) reconstruction and tumor mapping: providing a 3D view of maxillary tumor and adjacent structures and helping to make the diagnosis of maxillary tumor accurate and objective; (2) Virtual planning: simulating tumor resection and maxillectomy as well as fibula reconstruction on the computer, so that to make an ideal surgical plan; (3) 3D printing: producing a 3D stereo model for prebending individualized titanium mesh and also providing template or cutting guide for the surgery; (4) Surgical navigation: the bridge between virtual plan and real surgery, confirming the virtual plan during the surgery and guarantee the accuracy; (5) Computer assisted analyzing and evaluating: making a quantitative and objective of the final result and evaluating the outcome. We also performed a series of studies to evaluate the application of computer assisted techniques used for maxillary reconstruction, including: (1) 3D tumor mapping technique for accurate
Soh, Hui Yuh; Muda, Ahmad Sobri; Jabar, Nazimi Abd; Nordin, Rifqah; Nabil, S; Ramli, Roszalina
Traumatic pseudoaneurysm involving the maxillary artery is rare. Owing to its anatomic location, internal maxillary artery is usually protected by its surrounding structures. Formation of pseudoaneurysm usually takes place after several weeks to months of the initial injury. In this case, we reported a pseudoaneurysm arising from left internal maxillary artery following blunt injuries within 3 hours after a road accident and the treatment with endovascular embolization with titanium coils prior to open reduction and internal fixation of the fractured mandibles.
Dadresanfar, Bahareh; Khalilak, Zohreh; Shahmirzadi, Solaleh
The maxillary first premolar may present large number of anatomic variations. The clinician should be aware of the configuration of the pulp system. Maxillary first premolars usually have two canals. The incidence of three canals in these teeth is quite rare. This case report presents the diagnosis and clinical management of a maxillary first premolar with two distinct canals in the apical third of buccal root (type IV), drawing particular attention to tactile examination of all the canal walls. PMID:23864875
Bayome, Mohamed; Park, Jae Hyun; Kim, Ki Beom; Kim, Seong-Hun; Chung, Kyu-Rhim
Maxillary protraction is the conventional treatment for growing Class III patients with maxillary deficiency, but it has undesirable dental effects. The purpose of this report is to introduce an alternative modality of maxillary protraction in patients with dentoskeletal Class III malocclusion using a modified C-palatal plate connected with elastics to a face mask. This method improved skeletal measurements, corrected overjet, and slightly improved the profile. The patients may require definitive treatment in adolescence or adulthood. The modified C-palatal plate enables nonsurgical maxillary advancement with maximal skeletal effects and minimal dental side effects. PMID:26258067
Adhikari, Ashim N.; Heggie, Andrew A.C.; Shand, Jocelyn M.; Bordbar, Patrishia; Pellicano, Anastasia
Background: Mandibular distraction osteogenesis (MDO) is an effective method of treating upper airway obstruction (UAO) in micrognathic infants. The short-term outcomes include relief of UAO, avoidance of tracheostomy, and prompt discharge from hospital. However, it is a significant surgical procedure with potential associated morbidities. This study describes a cohort of infants managed using MDO over a twelve-year period. Methods: A retrospective chart review was undertaken for children who had MDO before the age of 5 years between 2000 and 2012. This was followed by a clinical review of the same cohort specifically looking for dental anomalies, nerve injuries, and scar cosmesis. Results: Seventy-three children underwent MDO at a mean age of 2 months [interquartile range (IQR), 1.7–4.2] for nonsyndromic infants and 3.3 months (IQR, 2.1–7.4) for those with syndromes. Infants were discharged from hospital, on average, 15 days after procedure. After MDO, of the 9 who were previously tracheostomy dependent, 5 (56%) were decannulated within 12 months and none of the nontracheostomy-dependent children required further airway assistance. The majority of children required supplemental feeding preoperatively but, 12 months postoperatively, 97% of the nonsyndromic infants fed orally. Thirty-nine children (53%) were reviewed clinically [median age, 5.1 y (IQR, 3.9–6.5)] with 18 being syndromic. Many of the mandibular first permanent and second primary molars had developmental defects, but there was a low rate of neurosensory deficit and good scar cosmesis. Conclusions: This study contributes further to the evidence base underpinning the management of micrognathic infants with UAO. PMID:27536491
This essay examines the conditions behind the 'Philippine Prison Thriller' video, a YouTube spectacle featuring the 1,500 inmates of Cebu Provincial Detention and Rehabilitation Centre (CPDRC) dancing to Michael Jackson's hit song 'Thriller'. The video achieved viral status after it was uploaded onto the video-sharing platform in 2007, and sparked online debates as to whether this video, containing recorded moving images of allegedly forced dancing, was a form of cruel and inhumane punishment or a novel approach to rehabilitation. The immense popularity of the video inspired creative responses from viewers, and this international popularity caused the CPDRC to host a monthly live dance show held in the prison yard, now in its seventh year. The essay explores how seemingly innocuous products of user-generated-content are imbued with ideologies that obscure or reduce relations of race, agency, power and control. By contextualising the video's origins, I highlight current Philippine prison conditions and introduce how video-maker/programme inventor/prison warden Byron Garcia sought to distance his facility from the Philippine prison majority. I then investigate the 'mediation' of 'Thriller' through three main issues. One, I examine the commodification and transformation from viral video to a thana-tourist destination; two, the global appeal of 'Thriller' is founded on public penal intrigue and essentialist Filipino tropes, mixed with a certain novelty factor widely suffused in YouTube formats; three, how dance performance and its mediation here are conducive to creating Foucault's docile bodies, which operate as a tool of distraction for the masses and ultimately serve the interests of the state far more than it rehabilitates(unconvicted and therefore innocent) inmates.
Hsu, Kean J.; Babeva, Kalina N.; Feng, Michelle C.; Hummer, Justin F.; Davison, Gerald C.
Studies have examined the impact of distraction on basic task performance (e.g., working memory, motor responses), yet research is lacking regarding its impact in the domain of think-aloud cognitive assessment, where the threat to assessment validity is high. The Articulated Thoughts in Simulated Situations think-aloud cognitive assessment paradigm was employed to address this issue. Participants listened to scenarios under three conditions (i.e., while answering trivia questions, playing a visual puzzle game, or with no experimental distractor). Their articulated thoughts were then content-analyzed both by the Linguistic Inquiry and Word Count (LIWC) program and by content analysis of emotion and cognitive processes conducted by trained coders. Distraction did not impact indices of emotion but did affect cognitive processes. Specifically, with the LIWC system, the trivia questions distraction condition resulted in significantly higher proportions of insight and causal words, and higher frequencies of non-fluencies (e.g., “uh” or “umm”) and filler words (e.g., “like” or “you know”). Coder-rated content analysis found more disengagement and more misunderstanding particularly in the trivia questions distraction condition. A better understanding of how distraction disrupts the amount and type of cognitive engagement holds important implications for future studies employing cognitive assessment methods. PMID:24904488
Shiferaw, Brook; Stough, Con; Downey, Luke
Alcohol intoxication and distraction are two of the leading factors associated with impaired driving and fatalities, especially among younger drivers. However, it is currently unclear how these conditions affect mechanisms of visual attention considered essential for driving. The present article first reviews the literature to provide an overview of visual attention as it relates to driving. Secondly, the effects of alcohol and distraction on neurocognitive mechanisms of visual attention are summarised to provide a background which informs discussion of selected driving studies. Visual scanning impairment is identified as a consequence of both alcohol and distraction. Thus, experimental studies combining the use of simulated driving and eye tracking technologies are selected and critically reviewed to assess the relationship between eye movements and driving errors as possible indicators of visual scanning impairment. Seven of the eight studies selected investigated the effects of distraction while only one addressed alcohol. Evaluation of these studies suggests that distraction may affect visual scanning by increasing cognitive load which interferes with visual processing. The evidence for effects of alcohol on drivers' visual scanning capacity is currently scarce due to the lack of research with a specific focus on impairments of eye movement in intoxicated drivers. Lack of consistency between studies is identified as a current issue which makes it difficult to compare the results of different studies. Finally, we note that our strict selection of driving studies to avoid greater disparity between them is a limitation of the present review.
Tanja-Dijkstra, Karin; Pahl, Sabine; White, Mathew P; Andrade, Jackie; Qian, Cheng; Bruce, Malcolm; May, Jon; Moles, David R
Dental anxiety creates significant problems for both patients and the dental profession. Some distraction interventions are already used by healthcare professionals to help patients cope with unpleasant procedures. The present study is novel because it a) builds on evidence that natural scenery is beneficial for patients, and b) uses a Virtual Reality (VR) representation of nature to distract participants. Extending previous work that has investigated pain and anxiety during treatment, c) we also consider the longer term effects in terms of more positive memories of the treatment, building on a cognitive theory of memory (Elaborated Intrusions). Participants (n = 69) took part in a simulated dental experience and were randomly assigned to one of three VR conditions (active vs. passive vs. control). In addition, participants were distinguished into high and low dentally anxious according to a median split resulting in a 3×2 between-subjects design. VR distraction in a simulated dental context affected memories a week later. The VR distraction had effects not only on concurrent experiences, such as perceived control, but longitudinally upon the vividness of memories after the dental experience had ended. Participants with higher dental anxiety (for whom the dental procedures were presumably more aversive) showed a greater reduction in memory vividness than lower dental-anxiety participants. This study thus suggests that VR distractions can be considered as a relevant intervention for cycles of care in which people's previous experiences affect their behaviour for future events.
Liu, Gin-Chung; Yen, Ju-Yu; Chen, Chiao-Yun; Yen, Cheng-Fang; Chen, Cheng-Sheng; Lin, Wei-Chen; Ko, Chih-Hung
We evaluated neural substrates related to the loss of control in college students with internet gaming disorder (IGD). We hypothesized that deficit in response inhibition under gaming cue distraction was the possible mechanism for the loss of control internet use. Eleven cases of IGD and 11 controls performed Go/NoGo tasks with/without gaming distraction in the functional magnetic resonance imaging scanner. When the gaming picture was shown as background while individuals were performing Go/NoGo tasks, the IGD group committed more commission errors. The control group increased their brain activations more over the right dorsolateral prefrontal cortex (DLPFC) and superior parietal lobe under gaming cue distraction in comparison with the IGD group. Furthermore, brain activation of the right DLPFC and superior parietal lobe were negatively associated with performance of response inhibition among the IGD group. The results suggest that the function of response inhibition was impaired under gaming distraction among the IGD group, and individuals with IGD could not activate right DLPFC and superior parietal lobe to keep cognitive control and attention allocation for response inhibition under gaming cue distraction. This mechanism should be addressed in any intervention for IGD.
LeMoult, Joelle; Yoon, K. Lira; Joormann, Jutta
Difficulty regulating emotions following stressful events is a hallmark of Major Depressive Disorder (MDD). Although individuals’ ability to regulate their emotions is believed to have direct consequences for both emotional and physical wellbeing, few studies have examined the cardiovascular effects of different emotion regulation strategies in MDD. To the best of our knowledge, the current study is the first to examine the effects of two emotion regulation strategies, cognitive distraction and rumination, on both self-reported sadness and respiratory sinus arrhythmia (RSA) in individuals with MDD and healthy controls (CTLs). Following a forced-failure stressor, participants were randomly assigned to a rumination or cognitive distraction condition. As expected, rumination increased sadness and triggered RSA withdrawal for both MDDs and CTLs. Interestingly, although cognitive distraction reduced sadness, it also triggered RSA withdrawal. Moreover, cognitive distraction was associated with greater RSA withdrawal for MDDs than CTLs. Thus, although depressed individuals are able to use cognitive distraction to emotionally recover from stress, it may be associated with greater cognitive effort. Adding low-cost physiological measures such as RSA into assessments has the potential to offer new and important information about the effects of emotion regulation on mental and physiological health. PMID:27199505
García-Pacios, Javier; Garcés, Pilar; Del Río, David; Maestú, Fernando
Unpleasant emotional distraction can impair the retention of non-emotional information in working memory (WM). Research links the prefrontal cortex with the successful control of such biologically relevant distractors, although the temporal changes in this brain mechanism remain unexplored. We use magnetoencephalography to investigate the temporal dynamics of the cognitive control of both unpleasant and pleasant distraction, in the millisecond (ms) scale. Behavioral results demonstrate that pleasant events do not affect WM maintenance more than neutral ones. Neuroimaging results show that prefrontal cortices are recruited for the rapid detection of emotional distraction, at early latencies of the processing (70-130 ms). Later in the processing (360-450 ms), the dorsolateral, the medial and the orbital sections of the prefrontal cortex mediate the effective control of emotional distraction. In accordance with the behavioral performance, pleasant distractors do not require higher prefrontal activity than neutral ones. These findings extend our knowledge about the brain mechanisms of coping with emotional distraction in WM. In particular, they show for the first time that overriding the attentional capture triggered by emotional distractors, while maintaining task-relevant elements in mind, is based on the early detection of such linked-to-survival information and on its later cognitive control by the prefrontal cortex. PMID:26067780
Jones, Kevin B; Inoue, Nozomu; Tis, John E; McCarthy, Edward F; McHale, Kathleen A; Chao, Edmund YS
A longitudinal orientation of fibers and trabeculae has been observed histologically within distracted callus. This study quantified the intensity and angle of orientation of trabeculae within a distracted callus. Sixteen New Zealand white rabbits underwent unilateral tibial callus distraction with an external fixator across a mid-diaphyseal osteotomy. Included were: a seven-day post-operative latency period, ten days of distraction at 0.5 mm every 12 hours, and 20 days of post-distraction consolidation before euthanasia. Tibiae were removed, stripped of soft tissue, sectioned, and processed for decalcified histology. Micrographs of mid-coronal sections of the callus were evenly divided into 12 regions and underwent Fast Fourier Transform (FFT) analysis of the digitized image to determine the angle and intensity of the orientation of the bony trabeculae within the callus. The microstructure of the regenerate callus demonstrated an angle of orientation that uniformly matched that of cortical bone in all of regions of the callus and an intensity of orientation which approached that of cortical bone. PMID:16089083
Basch, Corey H; Ethan, Danna; Rajan, Sonali; Basch, Charles E
Use of mobile devices has been cited as a distraction while driving, and more recently, among pedestrians crossing urban streets. In 2010, over half of New York City traffic fatalities were pedestrians. The aim of this study was to estimate the prevalence of distracted walking due to pedestrians' use of headphones, mobile phones, or both. Data were gathered by direct observations at the 10 intersections in Manhattan with the highest frequency of pedestrian-motor vehicle collisions. More than 1 in 4 of the >3500 pedestrians observed were distracted by mobile electronic devices while crossing during the 'walk' (28.8%) and 'don't walk' (26.3%) signals. Poisson regression analyses established there was a significant difference in individuals talking on a mobile device during the 'walk' signal versus the 'don't walk' signal; however, no other significant differences in other distracted walking behaviours were observed. This study contributes to the emerging literature on distracted walking behaviour by pedestrians in busy urban areas and can help to inform pedestrian-focused safety efforts.
Chung, Soon-Cheol; Choi, Mi-Hyun; Kim, Hyung-Sik; You, Na-Rae; Hong, Sang-Pyo; Lee, Jung-Chul; Park, Sung-Jun; Baek, Ji-Hye; Jeong, Ul-Ho; You, Ji-Hye; Lim, Dae-Woon; Kim, Hyun-Jun
This study investigated neuronal activation differences under two conditions: driving only and distracted driving. Driving and distraction tasks were performed using a Magnetic Resonance (MR)-compatible driving simulator with a driving wheel and pedal. The experiment consisted of three blocks, and each block had both a Rest phase (1 min) and a Driving phase (2 min). During the Rest phase, drivers were instructed to simply look at the stop screen without performing any driving tasks. During the Driving phase, each driver was required to drive at 110 km/h under two conditions: driving only and driving while performing additional distraction tasks. The results show that the precuneus, inferior parietal lobule, supramarginal gyrus, middle frontal gyrus, cuneus, and declive are less activated in distracted driving than in driving only. These regions are responsible for spatial perception, spatial attention, visual processing and motor control. However, the cingulate gyrus and sub-lobar regions (lentiform nucleus and caudate), which are responsible for error monitoring and control of unnecessary movement, show increased activation during distracted driving compared with driving only.
do Vale, Sónia; Selinger, Lenka; Martins, João Martin; Gomes, Ana Coelho; Bicho, Manuel; do Carmo, Isabel; Escera, Carles
Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulphate (DHEAS) have been reported to have memory enhancement effects in humans. A neuro-stimulatory action and an anti-cortisol mechanism of action may contribute to that relation. In order to study DHEA, DHEAS and cortisol relations to working memory and distraction, we recorded the electroencephalogram of 23 young women performing a discrimination (no working memory load) or 1-back (working memory load) task in an audio-visual oddball paradigm. We measured salivary DHEA, DHEAS and cortisol both before each task and at 30 and 60 min. Under working memory load, a higher baseline cortisol/DHEA ratio was related to higher distraction as indexed by an enhanced novelty P3. This suggests that cortisol may lead to increased distraction whereas DHEA may hinder distraction by leading to less processing of the distractor. An increased DHEA production with consecutive cognitive tasks was found and higher DHEA responses attributed to working memory load were related to enhanced working memory processing as indexed by an enhanced visual P300. Overall, the results suggest that in women DHEA may oppose cortisol effects reducing distraction and that a higher DHEA response may enhance working memory at the electrophysiological level.
Dabas, Jitender; Mohanty, Sujata; Chaudhary, Zainab; Rani, Amita
Distraction osteogenesis (DO) is becoming a popular method of reconstruction for maxillofacial bony deformities or defects secondary to trauma or surgical tumor ablation. However, the technique is very sensitive in terms of the rate and rhythm of distraction. Because of this, there is a need for monitoring of the distraction regenerate during the distraction as well as the consolidation period. The present study was conducted to assess the regenerate using two imaging modalities, namely, ultrasonography (USG) and cone beam computed tomography (CBCT) to determine their relative efficacies and to weigh their clinical usefulness in assessment of DO regenerate. The study was conducted on 12 patients (18 sites) who underwent mandibular distraction for correction of facial deformities. The results showed that overall USG correlated better with the condition of regenerate (r = 0.606) as compared with CBCT (r = 0.476). However, USG was less effective as compared with CBCT in assessing the regenerate once corticomedullary differentiation occurred in the bone. PMID:26889351
Meng, Q; Chen, G; Long, X; Deng, M; Cai, H; Li, J
Condylar hyperplasia is the excessive unilateral growth of mandibular leading to facial asymmetry, occlusal disturbance, joint pain and dysfunction. The aim of this study is to evaluate the histological presence of temporomandibular joint in model of condylar hyperplasia by lengthening unilateral condylar neck of distraction osteogenesis. An extra oral distractor was employed to achieve unilateral condylar neck distraction (1·0 mm daily for 7 days). The experimental condylar necks were elongated by 7 mm compared to the contralateral. Eleven adult white rabbits were used. Eight rabbits were, respectively, sacrificed after the post-distraction period (4 or 8 weeks). All animals were evaluated clinically and histomorphometrically. The condyles radiologically showed remodelling, flattening and sclerosis. In 4-week group, thinning of the cartilage was evident, and the trabeculae were long, not multiply connected. A thin, dense fibrous layer covered all over the surface of cartilage. In 8-week group, the cartilaginous layer was similar to thickness of the normal cartilage, but still thinner than control. However, the fibrous layers covering condyle manifested slight degenerative changes, and even depressions and erosions were seen in the cartilage and subchondral bone. The trabeculae showed denser and multiply connected. In 8-week group, the cartilaginous thickness of surgical condyles was significantly thinner than the contralateral. This study indicates that unilateral distraction of condylar neck loads the condyles asymmetrically. Asymmetrical loads affect more on the surgical condyles than the contralateral, and after 8 weeks of the post-distraction, condyle could recover from asymmetrical loads in some degree.
Babu, Sumanth; Manjunath, Shaurya; Vajawat, Mayuri
Mandibular discontinuity defects following a segmental mandibulectomy defects present a major challenge to the rehabilitation team. With no immediate intervention to rehabilitate the patient, definitive mandibular guidance prostheses with a metal guiding flange and acrylic teeth on the resected side can be used successfully to stabilize the occlusion and correct the deviation. The present case report describes the prosthodontic rehabilitation of a patient with a segmental mandibulectomy using a mandibular prosthesis with a metal guide flange and a maxillary stabilizing metal framework. PMID:27274352
da Silva, André Luis Fernandes; Borba, Alexandre Meireles; Bandeca, Matheus Coelho; Volpato, Luiz Evaristo Ricci; Porto, Alessandra Nogueira; Freitas, Diogo Loureiro; Borges, Alvaro Henrique
Obtaining a good cosmetic and proper mastication in oral rehabilitation with dental implants are directly linked to the correct positioning of the implant in the alveolar bone. The malposition of the implant is a challenge in rehabilitation, which can often compromise the entire process. In cases of severely malpositioned implants, one has the option to remove it or leave it submerged under bone and gums. Another option is the modified segmental osteotomy that aims repositioning osseointegrated implant with the surrounding bone. The objective of this case report is to present a case where an implant was severely malpositioned after surgically assisted rapid maxillary expansion, requiring a modified segmental osteotomy technique to reposition it. PMID:26464556
Expedition 33 Commander Suni Williams concludes her tour of the International Space Station with a visit to the Russian segment, which includes Zarya, the first segment of the station launched in 1...
Tseng, Linda L Y; Chang, Chris H; Roberts, W Eugene
A man, aged 28 years 9 months, came for an orthodontic consultation for a skeletal Class III malocclusion (ANB angle, -3°) with a modest asymmetric Class II and Class III molar relationship, complicated by an anterior crossbite, a deepbite, and 12 mm of asymmetric maxillary crowding. Despite the severity of the malocclusion (Discrepancy Index, 37), the patient desired noninvasive camouflage treatment. The 3-Ring diagnosis showed that treatment without extractions or orthognathic surgery was a viable approach. Arch length analysis indicated that differential interproximal enamel reduction could resolve the crowding and midline discrepancy, but a miniscrew in the infrazygomatic crest was needed to retract the right buccal segment. The patient accepted the complex, staged treatment plan with the understanding that it would require about 3.5 years. Fixed appliance treatment with passive self-ligating brackets, early light short elastics, bite turbos, interproximal enamel reduction, and infrazygomatic crest retraction opened the vertical dimension of the occlusion, improved the ANB angle by 2°, and achieved excellent alignment, as evidenced by a Cast Radiograph Evaluation score of 28 and a Pink and White dental esthetic score of 3.
Wang, Qi-Ke; Zhang, Ming; Li, Kai; Zhang, Dong
The Fanniidae is one of four families in the superfamily Muscoidea (Diptera), including some important medical and hygienic flies. There is a paucity of reports on the ultrastructure of olfactory sensilla for the fanniid species. To provide more information on the morphology of the antennal and palpal sensilla of fanniid fly, Fannia hirticeps (Stein, 1892) has been studied using scanning electron microscopy. The first two antennal segments, scape and pedicel, are covered by microtrichiae and several chaetic sensilla. Six distinct morphological types of sensilla are recorded on the antennal funiculus, including one trichoid, two basiconic, two coeloconic sensilla, and one clavate sensilla. The measurement and density of each sensilla type are also provided. The trichoid sensilla tend to be longer and denser toward the apex of antennal funiculus. Basiconic sensilla spread all over the funicular surface. F. hirticeps bears two types of coeloconic sensilla, type 2 coeloconic sensilla distributed on the distal part of the anterior surface, whereas type 1 distributed on the rest of the funiculus. Clavate sensilla are found on the base of antennal funiculus. Only one large sensory pit is located on the posterior surface. Maxillary palps bear one type of basiconic sensilla. These results are compared with eight other muscid flies. Our findings provide a morphological basis for future investigations on olfactory-mediated behavior of this group.
Kamio, Yoshinobu; Hiramatsu, Hisaya; Kamiya, Mika; Yamashita, Shuhei; Namba, Hiroki
Infratentorial cerebral hemorrhage due to a direct carotid–cavernous fistula (CCF) is very rare. To our knowledge, only four such cases have been reported. Cerebellar hemorrhage due to a direct CCF has not been reported. We describe a 63-year-old female who presented with reduced consciousness 3 days after undergoing a maxillectomy for maxillary cancer. Computed tomography showed a cerebellar hemorrhage. Magnetic resonance angiography showed a left-sided direct CCF draining into the left petrosal and cerebellar veins through the left superior petrosal sinus (SPS). Her previous surgery had sacrificed the pterygoid plexus and facial vein. Increased blood flow and reduced drainage could have led to increased venous pressure in infratentorial veins, including the petrosal and cerebellar veins. The cavernous sinus has several drainage routes, but the SPS is one of the most important routes for infratentorial venous drainage. Stenosis or absence of the posterior segment of the SPS can also result in increased pressure in the cerebellar and pontine veins. We emphasize that a direct CCF with cortical venous reflux should be precisely evaluated to determine the hemodynamic status and venous drainage from the cavernous sinus. PMID:28061497
Koerich, L; Burns, D; Weissheimer, A; Claus, J D P
This study aimed to validate a novel method for fast regional superimposition of cone beam computed tomography (CBCT) scans. The method can be used with smaller field of view scans, thereby allowing for a lower radiation dose. This retrospective study used two dry skulls and secondary data from 15 patients who had more than one scan taken using the same machine. Two observers tested two types of regional voxel-based superimposition: maxillary and mandibular. The registration took 10-15s. Three-dimensional surface models of the maxillas and mandibles were generated via standardized threshold segmentation, and the accuracy and reproducibility of the superimpositions were assessed using the iterative closest point technique to measure the root mean square (RMS) distance between the images. Five areas were measured and a RMS≤0.25 was considered successful. Descriptive statistics and the intra-class correlation coefficient (ICC) were used to compare the intra-observer measurement reproducibility. The ICC was ≥0.980 for all of the variables and the highest RMS found was 0.241. The inter-observer reproducibility was assessed case by case and was perfect (RMS 0) for 68% (23 out of 34) of the superimpositions done and not clinically significant (RMS≤0.25) for the other 32%. The method is fast, accurate, and reproducible and is an alternative to cranial base superimposition.
Chan, Harley; Gilbert, Ralph W.; Pagedar, Nitin A.; Daly, Michael J.; Irish, Jonathan C.; Siewerdsen, Jeffrey H.
esthetic appearance is one of the most important factors for reconstructive surgery. The current practice of maxillary reconstruction chooses radial forearm, fibula or iliac rest osteocutaneous to recreate three-dimensional complex structures of the palate and maxilla. However, these bone flaps lack shape similarity to the palate and result in a less satisfactory esthetic. Considering similarity factors and vasculature advantages, reconstructive surgeons recently explored the use of scapular tip myo-osseous free flaps to restore the excised site. We have developed a new method that quantitatively evaluates the morphological similarity of the scapula tip bone and palate based on a diagnostic volumetric computed tomography (CT) image. This quantitative result was further interpreted as a color map that rendered on the surface of a three-dimensional computer model. For surgical planning, this color interpretation could potentially assist the surgeon to maximize the orientation of the bone flaps for best fit of the reconstruction site. With approval from the Research Ethics Board (REB) of the University Health Network, we conducted a retrospective analysis with CT image obtained from 10 patients. Each patient had a CT scans including the maxilla and chest on the same day. Based on this image set, we simulated total, subtotal and hemi palate reconstruction. The procedure of simulation included volume segmentation, conversing the segmented volume to a stereo lithography (STL) model, manual registration, computation of minimum geometric distances and curvature between STL model. Across the 10 patients data, we found the overall root-mean-square (RMS) conformance was 3.71+/- 0.16 mm
Polanco-Roman, Lillian; Jurska, Justyna; Quiñones, Victoria; Miranda, Regina
The present study examined the relation between cognitive response styles (i.e., brooding, reflection, distraction) and cognitive inflexibility in differentially predicting history of non-suicidal self-injury (NSSI) only, suicide attempt (SA) only, or both (NSSI + SA). College students (N = 352) completed self-report measures of rumination, distraction, and self-harm history, a diagnostic interview, and a computerized task measuring cognitive flexibility. Brooding uniquely predicted SA-only history, while reflection uniquely predicted history of NSSI-only and NSSI + SA. Distraction was associated with lower odds of NSSI-only and NSSI + SA. Cognitive inflexibility was not significantly associated with self-harm history. Cognitive vulnerabilities may help identify individuals who are at risk for self-harm and may differentiate between NSSI and SA.
Polanco-Roman, Lillian; Jurska, Justyna; Quiñones, Victoria; Miranda, Regina
Objectives The present study examined the relation between cognitive response styles (i.e., brooding, reflection, distraction) and cognitive inflexibility in differentially predicting history of non-suicidal self-injury (NSSI) only, suicide attempt (SA) only, or both (NSSI+SA). Methods College students (N = 352) completed self-report measures of rumination, distraction, and self-harm history, a diagnostic interview, and a computerized task measuring cognitive flexibility. Results Brooding uniquely predicted SA-only history, while reflection uniquely predicted history of NSSI-only and NSSI+SA. Distraction was associated with lower odds of NSSI-only and NSSI+SA. Cognitive inflexibility was not significantly associated with self-harm history. Conclusion Cognitive vulnerabilities may help identify individuals who are at risk for self-harm and may differentiate between NSSI and SA. PMID:25517765
Marsh, John E; Vachon, François; Sörqvist, Patrik
Individuals with schizophrenia typically show increased levels of distractibility. This has been attributed to impaired working memory capacity (WMC), since lower WMC is typically associated with higher distractibility, and schizophrenia is typically associated with impoverished WMC. Here, participants performed verbal and spatial serial recall tasks that were accompanied by to-be-ignored speech tokens. For the few trials wherein one speech token was replaced with a different token, impairment was produced to task scores (a deviation effect). Participants subsequently completed a schizotypy questionnaire and a WMC measure. Higher schizotypy scores were associated with lower WMC (as measured with operation span, OSPAN), but WMC and schizotypy scores explained unique variance in relation to the mean magnitude of the deviation effect. These results suggest that schizotypy is associated with heightened domain-general distractibility, but that this is independent of its relationship with WMC.
Marini, Francesco; Demeter, Elise; Roberts, Kenneth C; Chelazzi, Leonardo; Woldorff, Marty G
Given the information overload often imparted to human cognitive-processing systems, suppression of irrelevant and distracting information is essential for successful behavior. Using a hybrid block/event-related fMRI design, we characterized proactive and reactive brain mechanisms for filtering distracting stimuli. Participants performed a flanker task, discriminating the direction of a target arrow in the presence versus absence of congruent or incongruent flanking distracting arrows during either Pure blocks (distracters always absent) or Mixed blocks (distracters on 80% of trials). Each Mixed block had either 20% or 60% incongruent trials. Activations in the dorsal frontoparietal attention network during Mixed versus Pure blocks evidenced proactive (blockwise) recruitment of a distraction-filtering mechanism. Sustained activations in right middle frontal gyrus during 60% Incongruent blocks correlated positively with behavioral indices of distraction-filtering (slowing when distracters might occur) and negatively with distraction-related behavioral costs (incongruent vs congruent trials), suggesting a role in coordinating proactive filtering of potential distracters. Event-related analyses showed that incongruent trials elicited greater reactive activations in 20% (vs 60%) Incongruent blocks for counteracting distraction and conflict, including in the insula and anterior cingulate. Context-related effects in occipitoparietal cortex consisted of greater target-evoked activations for distracter-absent trials (central-target-only) in Mixed versus Pure blocks, suggesting enhanced attentional engagement. Functional-localizer analyses in V1/V2/V3 revealed less distracter-processing activity in 60% (vs 20%) Incongruent blocks, presumably reflecting tonic suppression by proactive filtering mechanisms. These results delineate brain mechanisms underlying proactive and reactive filtering of distraction and conflict, and how they are orchestrated depending on distraction
Amir, Lisa R; Jovanovic, Andreas; Perdijk, Frits B T; Toyosawa, Satoru; Everts, Vincent; Bronckers, Antonius L J J
We tested the hypothesis that mechanical loading of human bone increases expression of the transcription factor RUNX2 and bone matrix proteins osteopontin (OPN), bone sialoprotein (BSP), dentin matrix protein-1 (DMP1), and matrix extracellular phosphoglycoprotein (MEPE). We examined this in tissue sections of atrophic mandibular bone taken from edentulous patients who had undergone distraction osteogenesis. In undistracted bone, weak to moderate staining for OPN and BSP was found in osteoblasts and bone matrix of immature woven bone. RUNX2 was also detectable in osteoblasts and in cells of the periosteum. In woven bone, but not in lamellar bone, a small number of osteocytes stained for all proteins tested. After distraction, staining intensity had increased in the existing old bone and staining was seen in more bone cells than before distraction. We also found a high expression of DMP1 and MEPE in many osteocytes embedded in woven bone and in some osteocytes of lamellar bone not seen before distraction. New bone trabeculae were forming in the fibrous tissue of the distraction gap containing all stages of intramembranous bone formation. Moderate to strong staining was seen for all five proteins tested in osteocytes located in woven bone of these trabeculae and for RUNX2, OPN, and BSP in osteoblasts lining the trabecular surfaces. We conclude that loading of atrophic human jawbone by distraction activates matrix synthesis of bone cells in and around existing bone. Increased staining of DMP1 and MEPE in osteocytes after loading is in line with the concept that these proteins may be involved in signaling the effector cells to adapt the bone structure to its mechanical demands.
Thompson, Leah L; Rivara, Frederick P; Ayyagari, Rajiv C; Ebel, Beth E
Objectives The objective of the present work was to study the impact of technological and social distraction on cautionary behaviours and crossing times in pedestrians. Methods Pedestrians were observed at 20 high-risk intersections during 1 of 3 randomly assigned time windows in 2012. Observers recorded demographic and behavioural information, including use of a mobile device (talking on the phone, text messaging, or listening to music). We examined the association between distraction and crossing behaviours, adjusting for age and gender. All multivariate analyses were conducted with random effect logistic regression (binary outcomes) and random effect linear regression (continuous outcomes), accounting for clustering by site. Results Observers recorded crossing behaviours for 1102 pedestrians. Nearly one-third (29.8%) of all pedestrians performed a distracting activity while crossing. Distractions included listening to music (11.2%), text messaging (7.3%) and using a handheld phone (6.2%). Text messaging, mobile phone use and talking with a companion increased crossing time. Texting pedestrians took 1.87 additional seconds (18.0%) to cross the average intersection (3.4 lanes), compared to undistracted pedestrians. Texting pedestrians were 3.9 times more likely than undistracted pedestrians to display at least 1 unsafe crossing behaviour (disobeying the lights, crossing mid-intersection, or failing to look both ways). Pedestrians listening to music walked more than half a second (0.54) faster across the average intersection than undistracted pedestrians. Conclusions Distracting activity is common among pedestrians, even while crossing intersections. Technological and social distractions increase crossing times, with text messaging associated with the highest risk. Our findings suggest the need for intervention studies to reduce risk of pedestrian injury. PMID:23243104
Hibberd, Daryl L; Jamson, Samantha L; Carsten, Oliver M J
Modern driving involves frequent and potentially detrimental interactions with distracting in-vehicle tasks. Distraction has been shown to slow brake reaction time and decrease lateral and longitudinal vehicle control. It is likely that these negative effects will become more prevalent in the future as advances are made in the functionality, availability, and number of in-vehicle systems. This paper addresses this problem by considering ways to manage in-vehicle task presentation to mitigate their distracting effects. A driving simulator experiment using 48 participants was performed to investigate the existence of the Psychological Refractory Period in the driving context and its effect on braking performance. Drivers were exposed to lead vehicle braking events in isolation (single-task) and with a preceding surrogate in-vehicle task (dual-task). In dual-task scenarios, the time interval between the in-vehicle and braking tasks was manipulated. Brake reaction time increased when drivers were distracted. The in-vehicle task interfered with the performance of the braking task in a manner that was dependent on the interval between the two tasks, with slower reactions following a shorter inter-task interval. This is the Psychological Refractory Period effect. These results have implications for driver safety during in-vehicle distraction. The findings are used to develop recommendations regarding the timing of in-vehicle task presentation so as to reduce their potentially damaging effects on braking performance. In future, these guidelines could be incorporated into a driver workload management system to minimise the opportunity for a driver to be distracted from the ongoing driving task.
Leiva, Alicia; Andrés, Pilar; Servera, Mateu; Verbruggen, Frederick; Parmentier, Fabrice B R
Sounds deviating from an otherwise repeated or structured sequence capture attention and affect performance in an ongoing visual task negatively, testament to the balance between selective attention and change detection. Although deviance distraction has been the object of much research, its modulation across the life span has been more scarcely addressed. Recent findings suggest possible connections with working memory and response inhibition. In this study we measured the performance of children and young and older adults in a cross-modal oddball task (deviance distraction), a working memory task (working memory capacity), and a response inhibition task (ability to voluntarily inhibit an already planned action) with the aim to establish the contribution of the latter 2 to the first. Older adults exhibited significantly more deviance distraction than children and young adults (who did not differ from each other). Working memory capacity mediated deviance distraction in children and older adults (though in opposite directions) but not in young adults. Response inhibition capacities did not mediate deviance distraction in any of the age groups. Altogether the results suggest that although the increase in deviance distraction observed in old age may partly reflect the relative impairment of working memory mechanisms, there is no straightforward and stable relation between working memory capacity and deviance distraction across the life span. Furthermore, our results indicate that deviance distraction is unlikely to reflect the temporary inhibition of responses. (PsycINFO Database Record
Kahn, Christopher A.; Cisneros, Victor; Lotfipour, Shahram; Imani, Ghasem; Chakravarthy, Bharath
For years, public health experts have been concerned about the effect of cell phone use on motor vehicle collisions, part of a phenomenon known as “distracted driving.” The Morbidity and Mortality Weekly Report (MMWR) article “Mobile Device Use While Driving - United States and Seven European Countries 2011” highlights the international nature of these concerns. Recent (2011) estimates from the National Highway Traffic Safety Administration are that 10% of fatal crashes and 17% of injury crashes were reported as distraction-affected. Of 3,331 people killed in 2011 on roadways in the U.S. as a result of driver distraction, 385 died in a crash where at least one driver was using a cell phone. For drivers 15–19 years old involved in a fatal crash, 21% of the distracted drivers were distracted by the use of cell phones. Efforts to reduce cell phone use while driving could reduce the prevalence of automobile crashes related to distracted driving. The MMWR report shows that there is much ground to cover with distracted driving. Emergency physicians frequently see the devastating effects of distracted driving on a daily basis and should take a more active role on sharing the information with patients, administrators, legislators, friends and family. PMID:26759649
Iordan, A D; Dolcos, F
Previous investigations showed that the impact of negative distraction on cognitive processing is linked to increased activation in a ventral affective system (VAS) and simultaneous deactivation in a dorsal executive system (DES). However, less is known about the influences of positive valence and different arousal levels on these effects. FMRI data were recorded while participants performed a working memory (WM) task, with positive and negative pictures presented as distracters during the delay between the memoranda and probes. First, positive distraction had reduced impact on WM performance, compared with negative distraction. Second, fMRI results identified valence-specific effects in DES regions and overlapping arousal and valence effects in VAS regions, suggesting increased impact of negative distraction and enhanced engagement of coping mechanisms for positive distraction. Third, a valence-related rostro-caudal dissociation was identified in medial frontal regions associated with the default-mode network (DMN). Finally, these DMN regions showed increased functional connectivity with DES regions for negative compared with positive distraction. Overall, these findings suggest that, while both positive and negative distraction engage partly similar arousal-dependent mechanisms, their differential impact on WM performance is linked to dissociations in the engagement of, and coupling between, regions associated with emotion processing and higher lever cognitive control.
Kitsoulis, P; Mantellos, G; Xenakis, Th
We describe a case of adamantinoma of the distal tibia in a 31-year-old woman. Segmental resection of the part of the tibia containing the tumour in normal bone was done and the bone defect was bridged with bone transport and external fixation. The tibia healed uneventfully and one year after the operation the patient resumed full activity. Three years postoperatively no local recurrence or metastasis has occurred.
Gao, Kenneth; Wiederhold, Brenda K.
Abstract Virtual reality (VR) has been used by clinicians to manage pain in clinical populations. This study examines the use of VR as a form of distraction for dental patients using both subjective and objective measures to determine how a VR system affects patients' reported anxiety level, pain level, and physiological factors. As predicted, results of self-evaluation questionnaires showed that patients experienced less anxiety and pain after undergoing VR treatment. Physiological data reported similar trends in decreased anxiety. Overall, the favorable subjective and objective responses suggest that VR distraction systems can reduce discomfort and pain for patients with mild to moderate fear and anxiety. PMID:24892198
Oviedo-Trespalacios, Oscar; Haque, Md Mazharul; King, Mark; Washington, Simon
The use of mobile phones while driving remains a major human factors issue in the transport system. A significant safety concern is that driving while distracted by a mobile phone potentially modifies the driving speed leading to conflicts with other road users and consequently increases crash risk. However, the lack of systematic knowledge of the mechanisms involved in speed adaptation of distracted drivers constrains the explanation and modelling of the extent of this phenomenon. The objective of this study was to investigate speed adaptation of distracted drivers under varying road infrastructure and traffic complexity conditions. The CARRS-Q Advanced Driving Simulator was used to test participants on a simulated road with different traffic conditions, such as free flow traffic along straight roads, driving in urbanized areas, and driving in heavy traffic along suburban roads. Thirty-two licensed young drivers drove the simulator under three phone conditions: baseline (no phone conversation), hands-free and handheld phone conversations. To understand the relationships between distraction, road infrastructure and traffic complexity, speed adaptation calculated as the deviation of driving speed from the posted speed limit was modelled using a decision tree. The identified groups of road infrastructure and traffic characteristics from the decision tree were then modelled with a Generalized Linear Mixed Model (GLMM) with repeated measures to develop inferences about speed adaptation behaviour of distracted drivers. The GLMM also included driver characteristics and secondary task demands as predictors of speed adaptation. Results indicated that complex road environments like urbanization, car-following situations along suburban roads, and curved road alignment significantly influenced speed adaptation behaviour. Distracted drivers selected a lower speed while driving along a curved road or during car-following situations, but speed adaptation was negligible in the
Wiederhold, Mark D; Gao, Kenneth; Wiederhold, Brenda K
Virtual reality (VR) has been used by clinicians to manage pain in clinical populations. This study examines the use of VR as a form of distraction for dental patients using both subjective and objective measures to determine how a VR system affects patients' reported anxiety level, pain level, and physiological factors. As predicted, results of self-evaluation questionnaires showed that patients experienced less anxiety and pain after undergoing VR treatment. Physiological data reported similar trends in decreased anxiety. Overall, the favorable subjective and objective responses suggest that VR distraction systems can reduce discomfort and pain for patients with mild to moderate fear and anxiety.
Rajakumar, Deshpande; Sharma, Ankit; Hari, Akshay; Konar, Subhas; Krishna, Murali
Cervical arthroplasty is being recognized as an emerging alternative to anterior cervical fusion with comparable or superior outcomes. The authors describe the surgical nuances of 2-level cervical arthroplasty in a case of 2-level degenerative disease. In this surgical technique, conventional vertebral body distraction has been avoided to prevent facet distraction, which can be a cause of persistent postoperative neck pain. Good motion preservation was observed at the 1-year follow-up examination. The video can be found here: https://youtu.be/YTpRVRXuZZk .
O'Callaghan, J P; Ullrich, C G; Yuan, H A; Kieffer, S A
Vertical distraction of the articular processes is an important sign of ligamentous disruption due to flexion injuries of the thoracolumbar spine. In addition to illustrating this finding in cross section (the "naked" facet), computed tomography in the transaxial plane allows assessment of the presence and position of fracture fragments that may encroach on the spinal canal. Image reconstruction in sagittal and coronal planes provides a clear demonstration of the degree of bony compression, facet distraction, and kyphosis associated with flexion injuries without additional patient manipulation or radiation exposure.
Saini, Narender; Patni, Purnima; Gupta, SP; Chaudhary, Lokesh; Sharma, Vishwadeep
Background: Treatment of radial clubhand has progressed over the years from no treatment to aggressive surgical correction. Various surgical methods of correction have been described; Centralization of the carpus over the distal end of the ulna has become the method of choice. Corrective casting prior to centralization is an easy and effective method of obtaining soft tissue stretching before any definitive procedure is undertaken. Moreover, it helps put the limb in a correct position. The outcome of deformity correction by serial casting / JESS distractor followed by centralization is discussed. Materials and Methods: In a prospective study, of 17 cases with 18 radial clubhands of Heikel's Grade III and IV (with average age 11 months (range 20 days – 24 months) with M:F of 2.6:1, were treated by gradual soft tissue stretching using corrective cast (14 cases) and JESS distraction (4 cases), followed by centralization (16 cases) or radialization (2 cases) and tendon transfers. Results: The average correction attained during the study was 71° of radial deviation and 31° of volar flexion. The average third metacarpal to distal ulna angle in anteroposterior and lateral view at final follow-up was 7° in both views. Angle of movement at elbow showed a small increase from 99° to 101° during the follow-up period. However, the range of movement at fingers showed increase in stiffness during the follow-up. No injury occurred to the distal ulnar epiphysis during the operative intervention. The results at the final follow-up, at the end of 2 years were graded on the basis of the criteria of F.W. Bora, and of Bayne and Klug. Considering the criteria of F.W. Bora, satisfactory result was shown by nine of the 18 hands (50%) while 16 out of 18 hands (89%) showed good or satisfactory result based on deformity criteria of Bayne and Klug. Conclusion: The management of radial clubhand by gradual corrective cast or JESS distractor followed by centralization and tendon transfers
Charlton, Judith L; Catchlove, Matthew; Scully, Michelle; Koppel, Sjaan; Newstead, Stuart
This study examined older driver engagement in distracting behaviours (secondary activities) at intersections using naturalistic driving data from a larger study based in Melbourne, Australia. Of interest was whether engagement in secondary activities at intersections was influenced by factors such as driver gender and situational variables, in particular, those relating to the complexity of the driving environment. Specifically we expected that when making left/right turns, older drivers would reduce the proportion of time engaged in secondary behaviours at intersections which required gap judgements (partly controlled or uncontrolled) compared with intersections that were fully controlled by traffic signals. Consideration was given to engagement in secondary activity with hands off the wheel and when the vehicle was moving versus stationary. Older drivers aged between 65 and 83 years drove an instrumented vehicle (IV) on their regular trips for approximately two weeks. The IV was equipped with a video camera system, enabling recording of the road environment and driver and a data acquisition unit, enabling recording of trip distance, vehicle speed, braking, accelerating, steering and indicator use. Driving experience and demographics were collected and functional abilities were assessed using the Useful Field of View (UFOV), Trail Making Test B, Mini Mental Status Examination (MMSE), visual acuity and contrast sensitivity. The study yielded a total of 371 trips with 4493 km (99.8 h) of naturalistic driving data including 1396 left and right turns. Trips were randomly selected from the dataset and in-depth analysis was conducted on 200 intersection manoeuvres (approximately 50% left turns, 50% right turns). The most frequently observed secondary activities were scratching/grooming (42.5%), talking/singing (30.2%) and manipulating the vehicle control panel (12.2%). Glances "off road" 2s or longer were associated with reading, reaching and manipulation of the
Sano, Natsuki; Kameda, Takashi; Terashima, Yukari; Batbayar, Nomintsetseg; Terada, Kazuto
Cases of congenitally missing and delayed eruption of the maxillary first molar are rare. However, in recent years, we have experienced cases of suspected delayed eruption of or congenitally missing first molars. The purpose of this study was to analyze the formation of delayed erupted maxillary first molars (M1) (>2 standard deviations), which play important roles in occlusion, and normal eruption of the maxillary first molars (U6). The frequency of M1 among patients born between 1974 and 1994 in one institution with a clear total patient number and personal oral histories was 1.55 % [80 % bilateral eruption in 8 of 806 male patients (0.99 %) and 23 of 1195 female patients (1.92 %)]. To evaluate the formation and eruption of M1 according to Moorrees's tooth formation stages, panoramic X-ray films were obtained every year for 73 patients with M1 from 3 institutions (20 male and 53 female patients, total 131 M1s) without systematic histories or genetic disorders. The development/growth curve of M1 was fitted to both the logistic curve and U6 curve. The M1 development/growth curve was started behind with U6 curve; however, the straight part of the M1 curve exhibited steep inclination compared with the straight part of the U6 curve. The curve of the eruption pathway of M1 also exhibited a sigmoid S shape. These results indicate that the development and migration speed of M1 are faster than that of U6, excluding the delayed start point. These results may help orthodontists in treatment planning for patients with M1.
Kurşun, Şebnem; Kılıç, Cenk; Özen, Tuncer
Purpose This study aimed to assess the reliability of measurements performed on three-dimensional (3D) virtual models of maxillary defects obtained using cone-beam computed tomography (CBCT) and 3D optical scanning. Materials and Methods Mechanical cavities simulating maxillary defects were prepared on the hard palate of nine cadavers. Images were obtained using a CBCT unit at three different fields-of-views (FOVs) and voxel sizes: 1) 60×60 mm FOV, 0.125 mm3 (FOV60); 2) 80×80 mm FOV, 0.160 mm3 (FOV80); and 3) 100×100 mm FOV, 0.250 mm3 (FOV100). Superimposition of the images was performed using software called VRMesh Design. Automated volume measurements were conducted, and differences between surfaces were demonstrated. Silicon impressions obtained from the defects were also scanned with a 3D optical scanner. Virtual models obtained using VRMesh Design were compared with impressions obtained by scanning silicon models. Gold standard volumes of the impression models were then compared with CBCT and 3D scanner measurements. Further, the general linear model was used, and the significance was set to p=0.05. Results A comparison of the results obtained by the observers and methods revealed the p values to be smaller than 0.05, suggesting that the measurement variations were caused by both methods and observers along with the different cadaver specimens used. Further, the 3D scanner measurements were closer to the gold standard measurements when compared to the CBCT measurements. Conclusion In the assessment of artificially created maxillary defects, the 3D scanner measurements were more accurate than the CBCT measurements. PMID:25793180
Paul, S J; Pietrobon, N
The aesthetics of anterior maxillary restorations and health of the surrounding tissues are primary determinants of the successful outcome of a clinical procedure. Various restorative materials and application techniques have been developed to achieve optimal aesthetics. While early porcelain-fused-to-metal restorations exhibited metal margins, the development of shoulder porcelain margins in the 1980s resulted in a significant aesthetic improvement. Only in the 1990s, however, did all-porcelain restorations finally achieve the strength and complete range of optical characteristics exhibited by the natural dentition.
Neeraja, R; Kayal, Vizhi G
The talon cusp is a developmental anomaly characterized by the presence of an accessory cusp like structure projecting from the cingulum area of the anterior teeth. Gemination is an anomaly caused by a single tooth germ that attempted to divide during its development. These developmental anomalies may cause clinical problems including esthetic impairment, pain, caries and tooth crowding. Co-occurrence of two anomalies in a teeth is rare. This paper presents an unusual case of talon cusp on geminated permanent lateral incisor. How to cite this article: Neeraja R, Kayal VG. A Rare Occurrence of Geminated-Taloned Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2012;5(2):136-138.
Kim, Kyung Yeon; Bae, Jung Ho; Park, Jee Soo; Lee, Seung-Sin
Extrapulmonary tuberculosis is not rare and occurs mainly in the head and neck region. Cervical tuberculous lymphadenopathy is the most common form of extrapulmonary tuberculosis. Sinonasal tuberculosis is known to occur very rarely due to the protective functions of sinonasal mucosa. Although some signs of sinonasal tuberculosis may be present, such as associated facial abscesses, the symptoms and signs are usually nonspecific. Clinical suspicion is important for timely diagnosis and proper management of sinonasal tuberculosis due to its rarity and nonspecific clinical presentation. We report a case of tuberculosis confined to the unilateral maxillary sinus that was first misdiagnosed as recurrent rhinosinusitis after endoscopic sinus surgery.
Grigor'eva, N V
Halotherapy was applied for non-puncture treatment of 45 patients with acute purulent maxillary sinusitis. The response was evaluated by changes in clinico-immunological, cytological, x-ray and bacteriological parameters. Halotherapy was found effective in the treatment of acute purulent maxillary sinusitis without puncture.
Purpose. Radiography is important in forensic odontology for the identification of humans. The maxillary sinus is the largest of the paranasal sinuses and first to develop. Sinus radiography has been used for identification of skeletal remains and determination of gender. Hence, the aim and objectives of the present study were to establish a new method for gender determination using maxillary sinus index from lateral cephalometric radiographs and to establish the reliability of maxillary sinus for gender determination. Methods. A total of 50 adult digital lateral cephalometric radiographs (25 males and 25 females) were included in the study. The maxillary sinus analysis was performed on these radiographs using the height and width measurement tools of Sidexis XG software. Maxillary sinus index was calculated, discriminant function analysis performed, and discriminant equation derived for determination of gender. Results. The mean maxillary sinus height and width were found to be higher in males, whereas the maxillary sinus index was greater in females. The discriminant function analysis derived in the study was able to differentiate the sex groups with sensitivity of 68% and specificity of 76%. Conclusions. From the results of the present study, it may be concluded that morphometric analysis of maxillary sinus can be used as a reliable tool in gender determination. PMID:28373883
Al-Saqabi, Farah Y; Fenlon, Michael R; Bavisha, Kalpesh A
Key Clinical Message This case shows an excellent esthetic treatment outcome using implant-retained crowns replacing maxillary laterals and canines in hypodontia patient with unusual incidence of spontaneous diastema closure after the placement of implants. To our knowledge, this is the first case report showing maxillary midline diastema closure after implant placement. PMID:25984308
Karthi, Muthukumar; Anbuselvan, Gobichettipalayam Jagatheeswaran; Kumar, Bhandari Pawan
A case report is presented of a class III malocclusion with a class III skeletal pattern and maxillary retrusion. Patient, a 10-year-old boy was treated with an orthopedic face mask in conjunction with rapid maxillary expansion and standard pre-adjusted edgewise appliance. Treatment was completed after 3 years and proved to be stable following the active treatment.
Garib, Daniela Gamba; Rosar, Julia Petruccelli; Sathler, Renata; Ozawa, Terumi Okada
Introduction: Cleft lip and palate are craniofacial anomalies highly prevalent in the overall population. In oral clefts involving the alveolar ridge, variations of number, shape, size and position are observed in maxillary lateral incisors. The objective of this manuscript is to elucidate the embryonic origin of maxillary lateral incisors in order to understand the etiology of these variations. Contextualization: The hypothesis that orofacial clefts would split maxillary lateral incisor buds has been previously reported. However, recent studies showed that maxillary lateral incisors have dual embryonic origin, being partially formed by both the medial nasal process and the maxillary process. In other words, the mesial half of the lateral incisor seems to come from the medial nasal process while the distal half of the lateral incisor originates from the maxillary process. In cleft patients, these processes do not fuse, which results in different numerical and positional patterns for lateral incisors relating to the alveolar cleft. In addition to these considerations, this study proposes a nomenclature for maxillary lateral incisors in patients with cleft lip and palate, based on embryology and lateral incisors position in relation to the alveolar cleft. Conclusion: Embryological knowledge on the dual origin of maxillary lateral incisors and the use of a proper nomenclature for their numerical and positional variations renders appropriate communication among professionals and treatment planning easier, in addition to standardizing research analysis. PMID:26560830
Claes, L; Veeser, A; Göckelmann, M; Horvath, D; Dürselen, L; Ignatius, A
We introduce a novel method of lateral callus distraction for bone formation, which avoids the conventional splitting and weakening of bones. At the medial aspect of the sheep tibia the periosteum was resected and small holes were drilled into the cortex to connect the bone surface with the marrow. A distraction device with a hydroxyapatite-coated titanium plate was fixed over the drilled area. After 10 days latency the plate was distracted perpendicular to the bone's long axis twice a day by 0.27 mm for 10 days. The newly formed tissue was then allowed 50 days of maturation. In a control group the plate was fixed 5.4mm distant from the bone surface. After 70 days all sheep were sacrificed and investigated histo-morphologically and with pQCT. Significantly more bone had developed between the lateral bone surface and the plate in the distraction group compared to the control group. There was exclusively intra-membranous bone formation with trabeculae oriented in the direction of the applied distraction. The main calcification occurred weeks after the last distraction. In conventional callus distraction the tissue strain caused by distraction is superimposed by the tissue deformation due to the deformation of the fixation device. In contrast, in the newly introduced lateral callus distraction method pure uniaxial strain occurs. From a mechano-biological point of view these results suggest that pure uniaxial strain induces exclusively intra-membranous bone formation. Furthermore, it shows that the anabolic effect of tissue strain is present even 50 days after the last stimulation by distraction.
Möhlhenrich, Stephan Christian; Heussen, Nicole; Peters, Florian; Steiner, Timm; Hölzle, Frank; Modabber, Ali
The morphometric analysis of maxillary sinus was recently presented as a helpful instrument for sex determination. The aim of the present study was to examine the volume and surface of the fully dentate, partial, and complete edentulous maxillary sinus depending on the sex. Computed tomography data from 276 patients were imported in DICOM format via special virtual planning software, and surfaces (mm) and volumes (mm) of maxillary sinuses were measured. In sex-specific comparisons (women vs men), statistically significant differences for the mean maxillary sinus volume and surface were found between fully dentate (volume, 13,267.77 mm vs 16,623.17 mm, P < 0.0001; surface, 3480.05 mm vs 4100.83 mm, P < 0.0001) and partially edentulous (volume, 10,577.35 mm vs 14,608.10 mm, P = 0.0002; surface, 2980.11 mm vs 3797.42 mm, P < 0.0001) or complete edentulous sinuses (volume, 11,200.99 mm vs 15,382.29 mm, P < 0.0001; surface, 3118.32 mm vs 3877.25 mm, P < 0.0001). For males, the statistically different mean values were calculated between fully dentate and partially edentulous (volume, P = 0.0022; surface, P = 0.0048) maxillary sinuses. Between the sexes, no differences were only measured for female and male partially dentate fully edentulous sinuses (2 teeth missing) and between partially edentulous sinuses in women and men (1 teeth vs 2 teeth missing). With a corresponding software program, it is possible to analyze the maxillary sinus precisely. The dentition influences the volume and surface of the pneumatic maxillary sinus. Therefore, sex determination is possible by analysis of the maxillary sinus event through the increase in pneumatization.
Borie, Eduardo; Watanabe, Plauto C.A.; Orsi, Iara A.; Fuentes, Ramón
INTRODUCTION Exostoses in paranasal sinuses have been reported in the otolaryngology literature, but they have not been described in the dental literature to our knowledge. The aim of this article is to describe an idiopathic and rare case of bilateral exostosis obtained by cone-beam computed tomography. PRESENTATION OF CASE The case shows a healthy and asymptomatic patient with a different size and form of exostoses in both maxillary sinuses. DISCUSSION It is difficult to clinically diagnose the antral exostosis due the asymptomatic nature of this condition, unless the approach would be through endoscope. Sometimes this condition is related with nasal irrigants, however in this case the patient asserted not having used nasal irrigation ever; thus, it is impossible to relate this kind of treatment as a principal cause. CONCLUSION The published data of exostoses in maxillary sinus seem to be limited in the dental literature, and this condition is important to consider in an implant treatment planning. Also, it is important to perform a follow-up of the cases in trying to find the possible causes of exostosis. PMID:25128728
Artun, Jon; Behbehani, Faraj; Thalib, Lukman
The purpose of this study was to identify risk factors for maxillary third molar impaction in adolescent orthodontic patients. Radiographs made before treatment (T1) and after treatment (T2) and at a minimum of 10 years postretention (T3) of 132 patients that allowed accurate diagnosis of impaction vs eruption of one or both maxillary third molars were evaluated. Although univariate logistic regression revealed that the decision to extract premolars reduced the risk of impaction by 76% (P < .01), this parameter was not included in the final prediction model at T1. Multiple logistic regression analyses revealed that third molar impaction could be predicted at T1 according to the size of the retromolar space and the amount of mesial molar movement that will occur during active appliance therapy, reducing the risk of impaction by 22% and 34% for every millimeter increase in distance, respectively (P < .01). At T2, multiple logistic regression revealed that the odds of impaction were more than 60 times higher (P < .01) if the third molar was angulated mesially as compared with less than 30 degrees distally relative to the occlusal plane and almost five times (P < .05) higher if the third molar was angulated more than 30 degrees distally as compared with less than 30 degrees distally. Similar analyses at T2 showed 29% reduced risk of impaction for every millimeter increase in retromolar space and 18% reduced risk for every degree increase in angle MP/SN (P < .01).
Singh, Shishir; Pawar, Mansing
Objective: The objective was to study the root canal morphology of South Asian Indian Maxillary molars using a tooth clearing technique. Materials and Methods: Hundred teeth each comprising of first, second, and third molars collected from different dental schools and clinics in India were subjected to standard dye penetration, decalcification and clearing procedure before being studied. Results: The first molar mesiobuccal roots exhibited 69% Type I, 24% Type II, 4% Type IV, 2% Type V, and 1% exhibited a Vertuccis Type VIII canal anatomy. In the group with three separate roots the second molar mesiobuccal roots in exhibited 80.6% Type I, 15.3% Type II, 2.7% Type IV, and 1.4% Type V canal anatomy while the third molars mesiobuccal roots exhibited 57.4% Type I, 32% Type II, 2.1% Type III, 8.5% Type IV, 1% had a Type V canal anatomy in the similar group. Conclusion: A varied root canal anatomy was seen in the mesiobuccal root canal of the maxillary molars. PMID:25713497
Stephens, C D
The cephalometric records of sixty-four Class II, Division 1 cases treated exclusively with removable orthodontic appliances have been used in a study of the manner in which maxillary central incisors tilt. The center of rotation was most frequently located in the middle third of the incisor root. The longer the time interval between the pre- and posttreatment cephalograms, the more apical was the rotation axis likely to be, an effect ascribed to growth changes in the maxilla. If the effects of growth are taken into account, it seems that the maxillary central incisor seldom, if ever, tilts about the apical third of its root when force levels customarily recommended for tipping movements are employed. The results suggest that the instantaneous and orthodontic centers of rotation are one and the same and support the view that the manner in which incisor teeth move in response to a single applied force depends principally on the physical properties of the tooth root, supporting bone, and periodontal membrane. An unexplained correlation was found between the rate of incisor movement measured at the cervical margin of the tooth and the level of the rotation center.
Bouchard, Carl; Landry, Pierre-Éric
The purpose of this study was to evaluate the accuracy of surgical splints and an external reference point to reposition the maxilla during orthognathic surgery. Before surgery, a radiological marker was inserted inside the orthodontic bracket of the first right maxillary molar. A surgical splint was utilized to reposition the maxilla in the sagittal and coronal planes after the osteotomy. The vertical position was established by measuring the distance between a Kirschner wire inserted at bony nasion and the orthodontic wire. Preoperative and postoperative cephalometric radiographs were obtained and manually traced. The radiological marker and the tip of the right maxillary incisor were used as specific landmarks. Their displacement on the pre- and postoperative radiographs was measured. The actual surgical movement of the maxilla was compared to the initial surgical planning. 23 patients met the inclusion criteria to participate in the study. The mean difference between the planned and executed movements of the maxilla was 0.1mm (p=0.71). The difference was not statistically significant for any given movements of the maxilla. The use of surgical splints made from model surgery combined with an external reference point at bony nasion is accurate methods for repositioning the maxilla during orthognathic surgery.
Brkovic, B M B; Zlatkovic, M; Jovanovic, D; Stojic, D
The main purpose of this study was to assess the clinical efficacy and haemodynamic effects of ropivacaine for infiltration anaesthesia in patients undergoing surgical removal of upper third molars. The safety profile of ropivacaine was also studied by investigating the maximal venous plasma concentration of ropivacaine and the reactivity to ropivacaine of isolated human infraorbital arteries. Ropivacaine in concentrations of 0.5, 0.75 and 1% achieved dose-dependent parameters of maxillary infiltration aneasthesia, clinically relevant in concentrations 0.75 and 1%. Postoperative needs for analgesics were observed in 67-100% of patients. Haemodynamic parameters were stable during surgery with significant changes occuring 10 min after surgery. After maxillary infiltration of 2.0 ml 1% ropivacaine, the maximum venous plasma concentration (Cmax) was 82+/-15 microg/l. On isolated human infraorbital artery, ropivacaine (10(-4)M) induced endothelium-independent contraction. This study suggests that 0.75 and 1% ropivacaine offers adequate and safe intraoperative analgesia but not successful postoperative pain control for the surgical removal of upper third molars.
Romano, Nayara; Souza-Flamini, Luis Eduardo; Mendonça, Isabela Lima; Silva, Ricardo Gariba
This paper reports a case of gemination in a maxillary lateral incisor with two root canals and crown-root dilaceration. A 16-year-old male patient was referred for endodontic treatment of the maxillary left lateral incisor and evaluation of esthetic and functional complaints in the anterior region. The patient reported trauma to the anterior primary teeth. There was no spontaneous pain, but the tooth responded positively to the vertical percussion test and negatively to the pulp vitality test. Clinical examination showed esthetic and functional alterations and normal periodontal tissues. CBCT imaging confirmed the suspicion of gemination and crown-root dilaceration and also revealed the presence of two root canals and periapical bone rarefaction. The root canals were instrumented with Reciproc R40 and 1% NaOCl irrigation and were filled by lateral condensation of gutta-percha and AH Plus sealer. The tooth was definitely restored with composite resin to recover esthetics. Continued follow-up over 6 months has shown absence of pain or clinical alterations as well as radiographic image suggestive of apical repair. PMID:28119787
Berry, Michael J.; Westfall, Aubrey
Cell phones are nearly ubiquitous in the college classroom. This study asks two primary questions regarding the making and breaking of in-class cell phone policies. In what manner are students using their phones and how can faculty members minimize the potential for phone-related distractions? To answer these questions we analyze original survey…
Parmentier, Fabrice B. R.; Elford, Gregory; Escera, Carles; Andres, Pilar; San Miguel, Iria
Unexpected stimuli are often able to distract us away from a task at hand. The present study seeks to explore some of the mechanisms underpinning this phenomenon. Studies of involuntary attention capture using the oddball task have repeatedly shown that infrequent auditory changes in a series of otherwise repeating sounds trigger an automatic…
Zeamer, Charlotte; Fox Tree, Jean E.
Literature on auditory distraction has generally focused on the effects of particular kinds of sounds on attention to target stimuli. In support of extensive previous findings that have demonstrated the special role of language as an auditory distractor, we found that a concurrent speech stream impaired recall of a short lecture, especially for…
... National Highway Traffic Safety Administration Visual-Manual NHTSA Driver Distraction Guidelines for In... vehicle safely and that are operated by the driver through visual-manual means (meaning ] the driver looking at a device, manipulating a device-related control with the driver's hand, and watching for...
... National Highway Traffic Safety Administration Visual-Manual NHTSA Driver Distraction Guidelines for In... visual-manual means (meaning the driver looking at a device, manipulating a device-related control with the driver's hand, and watching for visual feedback). The proposed NHTSA Guidelines list...
Baños, Rosa M; Escobar, Patricia; Cebolla, Ausias; Guixeres, Jaime; Alvarez Pitti, Julio; Lisón, Juan Francisco; Botella, Cristina
This study analyzes the potential of virtual reality (VR) to enhance attentional distraction in overweight children as they experience bodily sensations during exercise. It has been suggested that one reason why obese children stop exercising is the perception of bodily sensations. In a counterbalanced design, a total of 109 children (33 overweight, 10-15 years old) were asked to walk twice for 6 minutes on a treadmill under one of two conditions: (a) traditional condition (TC)-focusing their attention on their physical feelings and sensations or (b) distraction condition (DC)-focusing their attention on a virtual environment. Attentional focus during exercise, bad-good feeling states (pre- and postexperimental), perceived exertion (3 minutes and post), heart rate, and enjoyment were assessed. Results indicated that overweight children focused on internal information under the TC, but they significantly shifted their attention to regard the external environment in the DC. This attentional distraction effect of VR was more intense in overweight than in normal-weight children. No differences between groups were found when examining changes in feeling states and perceived exertion. VR increased enjoyment during exercise, and children preferred exercise using virtual environments. VR is useful to promote distraction and may help overweight and obese children to enjoy exercise.
Klein, C; Papageorge, M; Kovács, A; Carchidi, J E
With this case report we demonstrate a new technique useful in augmenting alveolar ridges after resection procedures or atrophic loss of volume. The augmentation is done by means of a new osteogenic distractor (manufactured by ACE Surgical Supply Co., Inc., Brockton, MA, USA), the distraction procedure is according to Ilizarov's principles.
Flowers, Patricia J.; O'Neill, Alice Ann M.
One hundred eighteen middle school students from three different settings listened individually to a music excerpt and a prose excerpt that were each 3.5 minutes long. As they listened, they clicked a computer touchpad whenever they were distracted either by thoughts or external events, then refocused on the holistic listening task. After…
Cheong, Pauline Hope; Shuter, Robert; Suwinyattichaiporn, Tara
Recent debates on the use of technology in classrooms have highlighted the significance of regulating students' off-task and multitasking behaviors facilitated by digital media. This paper investigates the communication practices that constitute professorial authority to manage college students' digital distractions in classrooms. Findings from…
Polka, Linda; Rvachew, Susan; Molnar, Monika
The role of selective attention in infant phonetic perception was examined using a distraction masker paradigm. We compared perception of /bu/ versus /gu/ in 6- to 8-month-olds using a visual fixation procedure. Infants were habituated to multiple natural productions of 1 syllable type and then presented 4 test trials (old-new-old-new). Perception…
Chung, Jaiho; Park, Dong Ha; Yoon, Soo Han
A 7-yr-old boy visited our surgical center with Pfeiffer syndrome type 1, presenting with macrocrania, broad big toe and thumb, exophthalmos, tongue protrusion, malocclusion with midfacial retrusion, mild respiratory difficulty due to minor upper airway obstruction, and developmental delay. He also exhibited anthrophobia with a passive character. The patient was treated with internal monoblock distraction osteogenesis to increase the intracranial and intraorbital volumes, and the nasal and pharyngeal airway spaces using two modular mid-facial internal distractors. For distraction, the latency period was 1 week, the daily activation of 1.0 mm was 20 days (total advancement 20 mm at the midline), and the consolidation period was 3 months. The follow-up computed tomography 12 months after surgery showed expansion of the brain and proper ossification in the distracted area. The patient also showed aesthetically good cranial contours, improved tongue and eyeball protrusion, no respiratory difficulty, and improved learning. We suggest that the internal distraction may last longer than an external type, resulting in a better bone fusion rate and successful expansion of craniofacial bones.
Schweizer, Tom A.; Kan, Karen; Hung, Yuwen; Tam, Fred; Naglie, Gary; Graham, Simon J.
Introduction: Non-invasive measurements of brain activity have an important role to play in understanding driving ability. The current study aimed to identify the neural underpinnings of human driving behavior by visualizing the areas of the brain involved in driving under different levels of demand, such as driving while distracted or making left turns at busy intersections. Materials and Methods: To capture brain activity during driving, we placed a driving simulator with a fully functional steering wheel and pedals in a 3.0 Tesla functional magnetic resonance imaging (fMRI) system. To identify the brain areas involved while performing different real-world driving maneuvers, participants completed tasks ranging from simple (right turns) to more complex (left turns at busy intersections). To assess the effects of driving while distracted, participants were asked to perform an auditory task while driving analogous to speaking on a hands-free device and driving. Results: A widely distributed brain network was identified, especially when making left turns at busy intersections compared to more simple driving tasks. During distracted driving, brain activation shifted dramatically from the posterior, visual and spatial areas to the prefrontal cortex. Conclusions: Our findings suggest that the distracted brain sacrificed areas in the posterior brain important for visual attention and alertness to recruit enough brain resources to perform a secondary, cognitive task. The present findings offer important new insights into the scientific understanding of the neuro-cognitive mechanisms of driving behavior and lay down an important foundation for future clinical research. PMID:23450757
Kelly, Conor M.
A commitment to holistic student formation in the liberal arts tradition and to the Catholic faith is a hallmark of most Catholic higher education institutions. To be most effective, Catholic institutions must adapt this central mission to changing circumstances in an age of ubiquitous mobile technologies and persistent digital distractions. By…