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Sample records for maxillary distraction osteogenesis

  1. Stability after Cleft Maxillary Distraction Osteogenesis or Conventional Orthognathic Surgery

    PubMed Central

    Svenstrup, Martin; Pedersen, Thomas Klit; Küseler, Annelise; Jensen, John; Nørholt, Sven Erik

    2015-01-01

    ABSTRACT Objectives To compare stability of maxillary advancements in patients with cleft lip and palate following distraction osteogenesis or orthognathic surgery. Material and Methods Inclusion criteria: 1) cleft lip and palate, 2) advancement > 8 mm. Eleven patients comprised the distraction osteogenesis group (DOG). Seven patients comprised the orthognathic treatment group (CONVG). Skeletal and soft tissue points were traced on lateral cephalograms: T1 (preoperatively), T2 (after surgery), T3 (follow-up). Group differences were analyzed using Students t-test. Results At T1-T2, advancement of 6.98 mm (P = 0.002) was observed in DOG. Horizontal overjet increased 11.62 mm (P = 0.001). A point-nasion-B point (ANB) angle increased 8.82° (P = 0.001). Aesthetic plane to upper lip was reduced 5.44 mm (P = 0.017) and the naso-labial angle increased 16.6° (P = 0.001). Vertical overbite (VOB) increased 2.27 mm (P = 0.021). In T2-T3, no significant changes were observed in DOG. In T1-T2, horizontal overjet increased 8.45 mm (P = 0.02). The ANB angle, 9.33° (P = 0.009) in CONVG. At T2-T3, VOB increased, 2.35 mm (P = 0.046), and the ANB angle reduced, 3.83° (P = 0.003). In T2-T3, no parameters changed in CONVG. At follow-up (T3), VOB increased in CONVG compared with DOG, (P = 0.01). Vertical position of A point differed between the groups (P = 0.04). No significant intergroup differences between soft tissue parameters occurred. Conclusions Distraction osteogenesis resulted in a stable position of the maxilla and movement upwards in vertical plane, however in case of orthognathic treatment sagittal relapse and a continued postoperatively downward movement was registered. PMID:26229581

  2. Perpendicular serial maxillary distraction osteogenesis in cleft lip and palate patients

    PubMed Central

    Ylikontiola, Leena P.; Sándor, George K.; Harila, Virpi

    2015-01-01

    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

  3. Maxillary distraction osteogenesis using Le Fort I osteotomy without intraoperative down-fracture.

    PubMed

    Yamauchi, K; Mitsugi, M; Takahashi, T

    2006-06-01

    The aim of this study is to present a technique for maxillary distraction osteogenesis using Le Fort I osteotomy without down-fracture. Six cleft-related patients suffering from severe midfacial deficiency were treated with maxillary distraction osteogenesis. The RED II system was chosen as the extraoral device and the Leipzig retention plate system to anchor the maxillary segment. Maxillary distraction osteogenesis was successful in all cases. Cephalometric and clinical evaluation after an average follow-up period of 1 year showed stable results with respect to skeletal and dental relationships. The SNA angle increased from 72.3 degrees to 81.4 degrees and the ANB angle increased by 11.0 degrees immediately after removing the distraction device. After 1 year, the sagittal bone gain remained and the SNA angle had decreased by 0.8 degrees . This technique seems to minimize the risk of the surgical procedure and shorten the operation time. It may become an alternative method for the treatment of patients with severe midfacial hypoplasia. PMID:16513321

  4. Use of anterior maxillary distraction osteogenesis in two cleft lip and palate patients

    PubMed Central

    Srivastava, Dhirendra; Ghassemi, Alireza; Ghassemi, Mehrangiz; Showkatbakhsh, Rahman; Jamilian, Abdolreza

    2015-01-01

    Distraction osteogenesis (DO) has become a mainstream surgical technique for patients with jaw deformities. The aim of this study was to report the effect of DO done by a hyrax screw incorporated in an acrylic plate in the treatment of two maxillary deficient cases with cleft lip and palate. Two patients, a 24-year-old female and a 29-year-old male who suffered from maxillary deficiency and cleft lip and palate, were treated by DO. After making vertical cuts between the premolars on both sides and horizontal cuts similar to Le Fort 1, a hyrax screw was mounted on an acrylic plate for the slow anteroposterior expansion of maxillary arch. The expansion was achieved by turning the hyrax screw 0.8 mm per day after the latency period. Treatment was discontinued after achieving satisfactory over jet and occlusion. This study showed that anterior maxillary distraction is a reliable technique for correction of midfacial deformity arising out of cleft lip and palate. Incidences of complications are negligible compared to total maxillary distraction. PMID:26668459

  5. Biomechanical comparison of two intraoperative mobilization techniques for maxillary distraction osteogenesis: Down-fracture versus non-down-fracture

    PubMed Central

    Yang, Lili; Suzuki, Eduardo Yugo; Suzuki, Boonsiva

    2014-01-01

    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

  6. Long-term skeletal stability after maxillary advancement with distraction osteogenesis using a rigid external distraction device in cleft maxillary deformities.

    PubMed

    Figueroa, Alvaro A; Polley, John W; Friede, Hans; Ko, Ellen W

    2004-11-01

    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

  7. Maxillary distraction osteogenesis for treatment of cleft lip and palate in a patient with X-linked agammaglobulinemia.

    PubMed

    Sato, Yutaka; Mishimagi, Takashi; Katsuki, Yuko; Harada, Kiyoshi

    2014-07-01

    X-linked agammaglobulinemia (XLA) is a congenital immune deficiency disorder caused by abnormal antibody production. It is a rare disease with an estimated frequency of 1 in 379,000 that has X-linked recessive heredity and develops only in males. The clinical problems include bacterial infection such as otitis media, sinusitis, and bronchitis. In recent years it has become possible to diagnose XLA in the early stage and intravenous immunoglobulin replacement therapy has permitted survival to adulthood. However, there have been no reports of oral surgery in patients with XLA. Here, we describe a case in which immunoglobulin replacement therapy given pre- and postoperatively was used to control infection in oral surgery and maxillary distraction osteogenesis performed for improving occlusion and appearance of a cleft lip and palate in a patient with XLA. PMID:24947966

  8. Distraction Osteogenesis Update: Introduction of Multidirectional Cranial Distraction Osteogenesis.

    PubMed

    Gomi, Akira; Sunaga, Ataru; Kamochi, Hideaki; Oguma, Hirofumi; Sugawara, Yasushi

    2016-05-01

    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

  9. Distraction Osteogenesis Update: Introduction of Multidirectional Cranial Distraction Osteogenesis

    PubMed Central

    Sunaga, Ataru; Kamochi, Hideaki; Oguma, Hirofumi; Sugawara, Yasushi

    2016-01-01

    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

  10. Neonatal Mandibular Distraction Osteogenesis

    PubMed Central

    Flores, Roberto L.

    2014-01-01

    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

  11. Neonatal mandibular distraction osteogenesis.

    PubMed

    Flores, Roberto L

    2014-11-01

    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

  12. Callus stimulation in distraction osteogenesis.

    PubMed

    Mofid, Mehrdad M; Inoue, Nozomu; Atabey, Atay; Marti, Guy; Chao, Edmund Y S; Manson, Paul N; Vander Kolk, Craig A

    2002-04-15

    Distraction osteogenesis has been described as in vivo tissue engineering. The ability to stimulate this process for the repair of bony defects or lengthening of congenitally shortened facial structures is likely to significantly impact the field of craniofacial surgery. The purpose of this study was to determine whether mechanical stimulation of the distracted rabbit mandible would accelerate the maturation of the bony callus when applied during the early consolidation period. Twenty adult New Zealand White rabbits underwent unilateral mandibular osteotomy. A uni-directional internal distractor device (Synthes, Paoli, Pa.) was positioned along a plane perpendicular to the line of osteotomy. After a 7-day latency period, distraction was commenced at a rate of 1.0 mm/day for 12 days in all animals. In a control group of 10 rabbits, a consolidation period of 8 weeks was observed before they were killed. In the experimental group of 10 rabbits, daily alternate compression and distraction of 1 mm (sequential compression and distraction) was performed for 3 weeks followed by a 5-week period of rigid fixation. Each animal received a dose of a fluorescent label at three different time points during the study: at the end of the distraction period, 3 weeks after the completion of the distraction phase, and 3 days before it was killed. All animals were killed 8 weeks after the completion of the distraction phase. Undecalcified histologic analysis and 3-point bending tests to failure were performed on the extracted mandibles. The results of the experimental and control groups were compared. Four animals in the control group and three animals in the experimental group were excluded from the study because of screw loosening resulting in distractor dislodgment or because of infection. On histologic analysis, cortical thickness at the center of the callus was found to be significantly greater in the experimental group compared with the control group when normalized to the

  13. Vertical Alveolar Ridge Augmentation by Distraction Osteogenesis

    PubMed Central

    Kumar, N. Nanda; Ravindran, C.

    2015-01-01

    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

  14. Angiogenesis and mineralization during distraction osteogenesis.

    PubMed Central

    Choi, In Ho; Chung, Chin Youb; Cho, Tae-Joon; Yoo, Won Joon

    2002-01-01

    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

  15. Dento-Alveolar Distraction Osteogenesis for rapid Orthodontic Canine Retraction

    PubMed Central

    Kumar, Naveen; Prashantha, GS; Raikar, Sudhir; Ranganath, Krishnappa; Mathew, Silju; Nambiar, Sandeep

    2013-01-01

    Background: The objectives of this study were to evaluate the rate of canine distalization by segmental alveolar distraction method in first premolar extraction cases, to evaluate the displacement of the canine and first molar teeth, to assess the effects of the procedure on the pulpal vitality of the canines, and to determine the amount of root resorption in retracted canines. Materials & Methods: The sample of the study consisted of 20 teeth in 7 patients (five females and two males, mean age 18.5 years). After the osteotomy procedure distractor was fixed. After 3 days of consolidation period, the distractor was activated 3 quarter turns per day(0.75 mm/day) till the canines comes in contact with second premolar. An electrical vitality test was applied before and after the distraction procedure and during the follow-up period. Results: The mean distal retraction of canines was 7.262 ± 0.4864 mm. The distal displacement of the canine was mainly a combination of tipping and translation. The mean distraction procedure was completed in 14.60 ±1.536 days. The duration of retraction was less for mandibular canine compared to maxillary canine. The mean posterior anchorage loss was mean 0.50±0.688 mm. The amount of root resorption that occurred during distraction was clinically insignificant. None of the teeth reacted negatively to the electrical vitality test that was performed 6 months after the completion of the distraction procedure. There was no clinical sign of discoloration or pulpal pain in any tooth. Conclusion: With dentoalveolar distraction, as canines can be fully retracted in 12 to 16 days, the non-compliance patients, patients with root-shape malformations, periodontal problems, or ankylosed teeth will benefit from this technique. The anchorage teeth can withstand the retraction forces better with no anchorage loss, and without clinical or radiographic evidence of root resorption, ankylosis, periodontal problems, and soft tissue dehiscence. This

  16. Mandibular lengthening by distraction osteogenesis in the setting of osteogenesis imperfecta.

    PubMed

    Black, Jonathan S; Denny, Arlen D

    2015-01-01

    Osteogenesis imperfecta (OI) is an inherited disorder characterized by bone fragility and deformity. The craniofacial skeleton may be involved either primarily or by result of a concomitant diagnosis. Distraction osteogenesis has emerged as a versatile reconstructive option for many craniofacial deformities. Mandibular lengthening by distraction has not been reported in a patient with OI. We present a patient in whom mandibular lengthening was successfully performed twice for hemifacial microsomia. Bilateral lengthening was initially performed with successful airway improvement. This was followed by transport distraction on the more severely affected side for condylar reconstruction. Successful mandibular lengthening by distraction is possible in the setting of OI. PMID:25565236

  17. Cisplatin inhibits bone healing during distraction osteogenesis.

    PubMed

    Stine, Kimo C; Wahl, Elizabeth C; Liu, Lichu; Skinner, Robert A; Vanderschilden, Jacquelyn; Bunn, Robert C; Montgomery, Corey O; Suva, Larry J; Aronson, James; Becton, David L; Nicholas, Richard W; Swearingen, Christopher J; Lumpkin, Charles K

    2014-03-01

    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 (2 mg/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 five-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

  18. Unilateral mandibular ramus elongation by intraoral distraction osteogenesis.

    PubMed

    Kofod, Thomas; Nørholt, Sven Erik; Pedersen, Thomas Klit; Jensen, John

    2005-03-01

    Successful correction of facial asymmetry by mandibular distraction osteogenesis relies on mastering vector control. Lack of necessary vector control continues to compromise the treatment modality. The purpose of this study was to describe a new simplified method for vector transfer and to evaluate this method according to the outcome and the efficacy of distraction osteogenesis in the correction of unilateral mandibular hypoplasia and asymmetry. Twenty-seven patients with unilateral hypoplasia of the mandibular ramus underwent unilateral mandibular distraction osteogenesis with intraoral distraction devices. Posterior-anterior and lateral cephalograms were analyzed by digitalization. Changes in sagittal, vertical, and transversal linear and angular dimensions after the distraction treatment were evaluated by measurements performed on headfilms taken before and after surgery. Means and variances were calculated for selected cephalometric variables for each time point. The differences between the control and the treatment side were calculated, statistically described, and compared with a paired Student t test. Correction of the mandibular asymmetry, chin position, and the canting of the occlusal plane was obtained in all patients clinically, as well as radiographically, by the use of intraoral unidirectional distraction osteogenesis. PMID:15750421

  19. Relationships between tissue dilatation and differentiation in distraction osteogenesis

    PubMed Central

    Morgan, Elise F.; Longaker, Michael T.; Carter, Dennis R.

    2007-01-01

    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. PMID:16330195

  20. Miniature osmotic actuators for controlled maxillofacial distraction osteogenesis

    NASA Astrophysics Data System (ADS)

    Li, Yu-Hsien; Su, Yu-Chuan

    2010-06-01

    We have successfully demonstrated miniature actuators that are capable of converting chemical potential directly into steady mechanical movements for maxillofacial distraction osteogenesis. Pistons and diaphragms powered by osmosis are employed to provide the desired linear and volumetric displacements for bone distraction and potentially the release of bone morphogenetic proteins, respectively. The cylindrical-shaped miniature actuators are composed of polymeric materials and fabricated by molding and assembly processes. In the prototype demonstration, vapor-permeable thermoplastic polyurethane was employed as the semi-permeable material. 3 cm long actuators with piston and diaphragm radii of 1 mm and 500 µm, respectively, were fabricated and characterized. The maximum distraction force from the piston-type actuator is found to be 6 N while the piston travels at a constant velocity of 32 µm h-1 (or 0.77 mm/day) for about 1 week. Meanwhile, the release rate from the diaphragm-type actuator is measured to be constant, 0.15 µl h-1 (or 3.6 µl/day), throughout the experiment. Moreover, the sizes and output characteristics of the self-regulating actuators could readily be tailored to realize optimal distraction rate, rhythm and osteogenic activity. As such, the demonstrated miniature osmotic actuators could potentially serve as versatile apparatuses for maxillofacial distraction osteogenesis and fulfill the needs of a variety of implantable and biomedical applications.

  1. Masticatory Mechanics of a Mandibular Distraction Osteogenesis Site: Interfragmentary Micromovement

    PubMed Central

    Sun, Zongyang; Rafferty, Katherine L.; Egbert, Mark A.; Herring, Susan W.

    2007-01-01

    Micromovement at a fracture or distraction osteogenesis (DO) site may play an important 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 (με) 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. PMID:17532283

  2. Versatility of Distraction Osteogenesis for the Craniofacial Skeleton.

    PubMed

    Klement, Kristen A; Black, Jonathan S; Denny, Arlen D

    2016-05-01

    Malformations of the craniofacial skeleton are common. Restoration of anatomic shape, size, and position has been traditionally accomplished using autologous bone grafting to fill gaps created by surgery and segmental movement. The authors present their practice using distraction in many different ages and settings over 20 years. A retrospective review was performed of all craniofacial patients treated using distraction osteogenesis for mandible, midface, and calvarium. The authors identified 205 patient. Mandible: 112 patients were treated at an average age of 3.4 years. 18.8% of patients required repeat distraction. There was no difference in the neonatal versus older group (P = 0.71). There were significantly higher reoperation rates in syndromic children (P < 0.01). Midface: 58 patients underwent Lefort III distraction at an average age of 13.6 years. One (1.7%) required repeat distraction (Miller syndrome). Five (8.6%) patients underwent subsequent Lefort I advancement for occlusal changes. Calvarium: 33 patients were treated at an average age of 4.7 years. No repeat distractions were performed. One patient required an additional advancement procedure. Distraction demonstrates successful long-term correction of defects in the craniofacial skeleton with the versatility and control needed to treat the wide spectrum of deformity. PMID:26999694

  3. Bimaxillary distraction osteogenesis used for treatment of crowding in non-growing individuals. Case report.

    PubMed

    Corega, C; Vaida, L; Festila, D G; Rigoni, G; Albanese, M; D'Agostino, A; Chiarini, G; Nocini, P F; Bertossi, D

    2014-01-14

    Dental crowding is frequently associated with transverse jaw discrepancies, resulting in a less-than-ideal position of the teeth in the basal bone. The classic aproach for correcting bimaxillary crowding are extractions or arch expansion. Rapid maxilla-mandibular expansion was used to treat transverse discrepancies in growing patients, but with aging, the upper and lower jaw bones become increasingly resistant to expansion. The surgically assisted rapid maxillary expansion (SARME) and the mandibular midsymphyseal distraction osteogenesis procedure overcome this age limitation and are of great importance for the treatment of transverse discrepancies in adults. The aim of this paper is to report a case with a severe transverse deficiency treated with SARME, mandibular midsymphyseal distraction together with orthodontic treatment in an adult patient. The case highlights the esthetic advantages of increasing the transversal dimension of both jaws in patients with severe crowding associated with constricted dental arches and recommends the maxillo-mandibular transverse distraction osteogenesis as an and effective form of surgical treatment for patients with malocclusions or dentofacial deformities featuring severe transverse discrepancies, combined with a carefully monitored orthodontic treatment. PMID:24423741

  4. Rapid maxillary canine retraction by dental distraction: A clinical study

    PubMed Central

    Koteswara Prasad, N. K.; Chitharanjan, Arun; Kailasam, Vignesh

    2014-01-01

    Aim: The aim of this clinical study was to perform rapid maxillary canine retraction through distraction of the periodontal ligament and investigate the rate and amount of canine retraction, amount of anchor loss, the nature of tooth movement achieved, and radiographic changes in the periodontal ligament region during and after canine distraction. Materials and Methods: This study was conducted on 10 distractions ranging in age from 14 years to 25 years who needed canine retraction and first premolar extraction in the maxillary arch. Ten canine distractions were carried out with custom-made, tooth-borne intra-oral distraction device. Results: The results indicate that the periodontal ligament can be distracted just like the mid-palatal suture in rapid palatal expansion and the maxillary canines are retracted rapidly into the first premolar extraction space at the rate of about 2.53 mm/week. Conclusion: Though this study indicates that the periodontal ligament can be distracted to elicit rapid tooth movement, the long-term effects of canine distraction are not well known and need close monitoring. PMID:25298710

  5. Pre-arthroplasty simultaneous maxillomandibular distraction osteogenesis for the correction of post-ankylotic dentofacial deformities.

    PubMed

    Mehrotra, D; Vishwakarma, K; Chellapa, A L; Mahajan, N

    2016-07-01

    The aim of this study was to evaluate the hard and soft tissue changes after pre-arthroplasty simultaneous maxillomandibular distraction osteogenesis for the correction of post-ankylotic dentofacial deformities. This prospective study included 10 patients with unilateral temporomandibular joint (TMJ) ankylosis who presented with a facial deformity and a maxillary cant. Informed patient consent was obtained for participation. Simultaneous maxillomandibular distraction was planned based on clinical and radiographic examinations. A horizontal mandibular osteotomy was performed in the ramus and the distractor device was fixed. A bilateral Le Fort I osteotomy was then performed and a four-hole straight plate was fixed on the contralateral zygomatic buttress to act as a fulcrum. After a latency period of 5 days, the distractor was activated twice daily by 0.5mm until the required vertical lengthening was achieved. Intermaxillary fixation was maintained during the entire distraction period. After a consolidation period of 8-12 weeks, the distractor was removed. The TMJ ankylosis was released and a temporal fascia interpositional arthroplasty was performed as second surgery, along with a genioplasty if needed. All patients were followed up for a period of 12-24 months. A marked improvement in the facial asymmetry was noted in all cases. The occlusal cant and mandibular retrusion improved satisfactorily, and the average postoperative inter-incisal opening was 35.6mm. Pre-arthroplasty simultaneous maxillomandibular distraction offers a good treatment outcome, as it allows improvements in facial aesthetics as well as function. PMID:26780926

  6. Biomechanical Configurations of Mandibular Transport Distraction Osteogenesis Devices

    PubMed Central

    Zapata, Uriel; Elsalanty, Mohammed E.; Dechow, Paul C.

    2010-01-01

    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

  7. Inhibin A enhances bone formation during distraction osteogenesis.

    PubMed

    Perrien, Daniel S; Nicks, Kristy M; Liu, Lichu; Akel, Nisreen S; Bacon, Anthony W; Skinner, Robert A; Swain, Frances L; Aronson, James; Suva, Larry J; Gaddy, Dana

    2012-02-01

    Given the aging population and the increased incidence of fracture in the elderly population, the need exists for agents that can enhance bone healing, particularly in situations of delayed fracture healing and/or non-union. Our previous studies demonstrated that overexpression of the gonadal peptide, human inhibin A (hInhA), in transgenic mice enhances bone formation and strength via increased osteoblast activity. We tested the hypothesis that hInhA can also exert anabolic effects in a murine model of distraction osteogenesis (DO), using both transgenic hInhA overexpression and administration of normal physiological levels of hInhA in adult male Swiss-Webster mice. Tibial osteotomies and external ring fixation were performed, followed by a 3-day latency period, 14-day distraction, and sacrifice on day 18. Supraphysiological levels of hInhA in transgenic mice, but not normal physiological levels of hInhA, significantly increased endosteal bone formation and mineralized bone area in the distraction gap, as determined by radiographic and µCT analysis. Significantly, increased PCNA and osteocalcin expression in the primary matrix front suggested that hInhA increased osteoblast proliferation. This mechanism is consistent with the effects of other agents and pathologies that modulate bone formation during DO, and demonstrates the potential of hInhA to enhance bone repair and regeneration. PMID:21809377

  8. Inhibin A enhances bone formation during distraction osteogenesis

    PubMed Central

    Perrien, Daniel S.; Nicks, Kristy M.; Liu, Lichu; Akel, Nisreen S.; Bacon, Anthony W.; Skinner, Robert A.; Swain, Frances L.; Aronson, James; Suva, Larry J; Gaddy, Dana

    2013-01-01

    Given the aging population and the increased incidence of fracture in the elderly population, the need exists for agents that can enhance bone healing, particularly in situations of delayed fracture healing and/or non-union. Our previous studies demonstrated that over-expression of the gonadal peptide, human Inhibin A (hInhA), in transgenic mice enhances bone formation and strength via increased osteoblast activity. We tested the hypothesis that hInhA can also exert anabolic effects in a murine model of distraction osteogenesis (DO), using both transgenic hInhA overexpression and administration of normal physiological levels of hInhA in adult male Swiss-Webster mice. Tibial osteotomies and external ring fixation were performed, followed by a 3 day latency period, 14 day distraction, and sacrifice on day 18. Supraphysiological levels of hInhA in transgenic mice, but not normal physiological levels of hInhA, significantly increased endosteal bone formation and mineralized bone area in the distraction gap, as determined by radiographic and µCT analysis. Significantly, increased PCNA and osteocalcin expression in the primary matrix front suggested that hInhA increased osteoblast proliferation. This mechanism is consistent with the effects of other agents and pathologies that modulate bone formation during DO, and demonstrates the potential of hInhA to enhance bone repair and regeneration. PMID:21809377

  9. Posterior Cranial Vault Distraction Osteogenesis with Barrel Stave Osteotomy in the Treatment of Craniosynostosis

    PubMed Central

    KOMURO, Yuzo; SHIMIZU, Azusa; SHIMOJI, Kazuaki; MIYAJIMA, Masakazu; ARAI, Hajime

    2015-01-01

    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

  10. Experience with Mandibular Reconstruction Using Transport-Disc-Distraction Osteogenesis

    PubMed Central

    Pingarrón-Martín, Lorena; Otero, T. González; Gallo, L.J. Arias

    2014-01-01

    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

  11. Stem Cells Rejuvenate Radiation-Impaired Vasculogenesis in Murine Distraction Osteogenesis

    PubMed Central

    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.

    2015-01-01

    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

  12. [Mandibular advancement: bilateral sagittal split versus -distraction osteogenesis].

    PubMed

    Akkerman, V; Ho, J P; Baas, E M; de Lange, J de

    2015-11-01

    In the 1990s intra-oral distraction osteogenesis (DO) became available as an alternative for bilateral sagittal splitosteotomy (BSSO) for advancement of the mandible. It was thought that DO would lead to more stability in the results and fewer neurosensory disturbances of the inferior alveolar nerve. However, there was no scientific evidence for this assumption. This article describes a number of recently published, prospective studies that demonstrate that BSSO is not inferior to DO with respect to stability and neurosensory disturbances of the inferior alveolar nerve. They also demonstrate that BSSO leads to less pain in patients and to lower total costs. It can be concluded that BSSO should be considered the standard therapy for mandibular advancement up to 10 mm in non-syndromal patients. PMID:26569001

  13. Complications of distraction osteogenesis in short first metatarsals.

    PubMed

    Oh, Chang Wug; Satish, B R J; Lee, Sung-Tae; Song, Hae-Ryong

    2004-01-01

    The authors analyzed the results and complications of metatarsal lengthening in short first metatarsals by distraction osteogenesis. There were 13 first metatarsal lengthenings in eight patients. Mean age was 18.8 years and the average percentage of lengthening was 49.2%. The average healing index was 72.4 days/cm. The major complication was cavus foot, which was noticed in four feet. All great toes showed some loss of motion at metatarsophalangeal (MP) joint. Other complications were hallux valgus, angulation of the metatarsals, and pin tract infection each in two feet. The functional score according to the American Orthopedic Foot and Ankle Society (AOFAS) hallux MP joint, interphalangeal joint scale was excellent in 11 and good in 2. All patients were satisfied with the procedure. To avoid potential complications such as MP joint subluxation, cavus foot, and hallux valgus, the first metatarsal lengthening should not exceed 50% of the original length. PMID:15502575

  14. Parathyroid Hormone Therapy Mollifies Radiation-Induced Biomechanical Degradation in Murine Distraction Osteogenesis

    PubMed Central

    Deshpande, Sagar S.; Gallagher, Katherine K.; Donneys, Alexis; Tchanque-Fossuo, Catherine N.; Sarhaddi, Deniz; Nelson, Noah S.; Chepeha, Douglas B.; Buchman, Steven R.

    2015-01-01

    Objective Descriptions of mandibular distraction osteogenesis for tissue replacement after oncologic resection or for defects caused by osteoradionecrosis have been limited. Previous work demonstrated radiation decreases union formation, cellularity and mineral density in mandibular distraction osteogenesis. The authors posit that intermittent systemic administration of parathyroid hormone will serve as a stimulant to cellular function, reversing radiation-induced damage and enhancing bone regeneration. Methods Twenty male Lewis rats were randomly assigned to three groups: group 1 (radiation and distraction osteogenesis, n = 7) and group 2 (radiation, distraction osteogenesis, and parathyroid hormone, n = 5) received a human-equivalent dose of 35 Gy of radiation (human bioequivalent, 70 Gy) fractionated over 5 days. All groups, including group 3 (distraction osteogenesis, n = 8), underwent a left unilateral mandibular osteotomy with bilateral external fixator placement. Distraction osteogenesis was performed at a rate of 0.3 mm every 12 hours to reach a gap of 5.1 mm. Group 2 was injected with parathyroid hormone (60 μg/kg) subcutaneously daily for 3 weeks after the start of distraction osteogenesis. On postoperative day 40, all left hemimandibles were harvested. Biomechanical response parameters were generated. Statistical significance was considered at p ≤ 0.05. Results Parathyroid hormone–treated mandibles had significantly higher failure load and higher yield than did untreated mandibles. However, these values were still significantly lower than those of nonirradiated mandibles. Conclusions The authors have successfully demonstrated the therapeutic efficacy of parathyroid hormone to stimulate and enhance bone regeneration in their irradiated murine mandibular model of distraction osteogenesis. Anabolic regimens of parathyroid hormone, a U.S. Food and Drug Administration–approved drug on formulary, significantly improve outcomes in a model of

  15. Le Fort I distraction using internal devices for maxillary hypoplasia in patients with cleft lip, palate, and alveolus: complications and their prevention and management.

    PubMed

    Mitsukawa, Nobuyuki; Satoh, Kaneshige; Morishita, Tadashi

    2010-09-01

    In recent years, advancement has been made in distraction osteogenesis in the facial area. It has been applied actively to treat maxillary hypoplasia in patients with cleft lip, palate, and alveolus. Le Fort I distraction using internal devices does not lead to disability in daily living, including during the retention period, and has low surgical invasiveness, facile management, and superior aesthetics. Thus, there have been occasional reports on this procedure in recent years. Because an internal device is unidirectional, the greatest disadvantage is the inability to adjust the direction of distraction after its placement. However, past reports have emphasized its advantages, and its complications have rarely been discussed. We performed Le Fort I distraction using internal devices on 15 young patients. Our results showed notable complications in a few cases. When serial cephalometric analysis was performed after maxillary distraction, it demonstrated that the maxilla assumes various three-dimensional distraction morphologies. In particular, cases with insufficient bone grafting of alveolar clefts developed collapse mainly in the alveolar cleft region during postoperative distraction. Mobility and deviation of the maxillary bone fragment occurred. We implemented preventative measures against complications such as using modifications to place the devices parallel on the left and right sides and using a bite splint for distraction. These measures produced improved outcomes, and we describe here the details. PMID:20856032

  16. The effect of aging on distraction osteogenesis in the rat.

    PubMed

    Aronson, J; Gao, G G; Shen, X C; McLaren, S G; Skinner, R A; Badger, T M; Lumpkin, C K

    2001-05-01

    The effect of age on bone formation in the limb lengthening model of distraction osteogenesis (DO) was investigated in two studies using Sprague-Dawley (SD) rats from two colonies at various ages (CAMM: 9 vs 24 months, Harlan: 4 vs 24 months). External fixators were placed on the right tibiae of 30 male SD rats (20 CAMM, 10 Harlan) and mid-diaphyseal osteotomies were performed. Distraction was performed at 0.2 mm bid for 20 days (CAMM) or 14 days (Harlan). The experimental (DO) and control (contra-lateral) tibiae were removed for high-resolution radiography and decalcified histology. Videomicroscopy was used to quantitate radiodensity, histology (matrix type) and relative areas of cell proliferation, which was identified by proliferating cell nuclear antigen (PCNA) immunochemistry. Both studies demonstrated an age-related decrease in the percent mineralized bone (radiodensity) in the distraction gap (CAMM 9 vs 24 months: 68% vs 51%, P < 0.003; Harlan 4 vs 24 months: 95% vs 36%, P < 0.001) and no significant colony or distraction time-specific difference was seen between the two colonies of 24-month-old rats. Histology was performed on the Harlan rats. The DO gaps in the 24-month-old rats demonstrated less endosteal new bone compared to the 4-month-old rats (P < 0.01), but equivalent periosteal new bone. In 4-month-old rats, PCNA-immunostained cells were organized along the primary matrix front (where the first deposition of osteoid occurs) extending across both periosteal and endosteal surfaces. In 24-month-old rats, PCNA+ cells were organized in zones along the periosteal new bone fronts only and irregularly scattered throughout the endosteal gap within a fibrovascular non-ossifying matrix. These results indicate that 24-month-old rats have a relative deficit in endosteal bone formation which may not be related to cell proliferation but rather to cell organization. This model reflects the clinical situation where radiographic findings in older patients demonstrate

  17. Regenerate Healing Outcomes in Unilateral Mandibular Distraction Osteogenesis Using Quantitative Histomorphometry

    PubMed Central

    Schwarz, Daniel A.; Arman, Krikor G.; Kakwan, Mehreen S.; Jamali, Ameen M.; Elmeligy, Ayman A.; Buchman, Steven R.

    2015-01-01

    Background The authors’ goal was to ascertain regenerate bone-healing metrics using quantitative histomorphometry at a single consolidation period. Methods Rats underwent either mandibular distraction osteogenesis (n=7) or partially reduced fractures (n=7); their contralateral mandibles were used as controls (n=11). External fixators were secured and unilateral osteotomies performed, followed by either mandibular distraction osteogenesis (4 days’ latency, then 0.3 mm every 12 hours for 8 days; 5.1 mm) or partially reduced fractures (fixed immediately postoperatively; 2.1 mm); both groups underwent 4 weeks of consolidation. After tissue processing, bone volume/tissue volume ratio, osteoid volume/tissue volume ratio, and osteocyte count per high-power field were analyzed by means of quantitative histomorphometry. Results Contralateral mandibles had statistically greater bone volume/tissue volume ratio and osteocyte count per high-power field compared with both mandibular distraction osteogenesis and partially reduced fractures by almost 50 percent, whereas osteoid volume/tissue volume ratio was statistically greater in both mandibular distraction osteogenesis specimens and partially reduced fractures compared with contralateral mandibles. No statistical difference in bone volume/tissue volume ratio, osteoid volume/tissue volume ratio, or osteocyte count per high-power field was found between mandibular distraction osteogenesis specimens and partially reduced fractures. Conclusions The authors’ findings demonstrate significantly decreased bone quantity and maturity in mandibular distraction osteogenesis specimens and partially reduced fractures compared with contralateral mandibles using the clinically analogous protocols. If these results are extrapolated clinically, treatment strategies may require modification to ensure reliable, predictable, and improved outcomes. PMID:20463629

  18. Alveolar vertical distraction osteogenesis: historical and biologic review and case presentation.

    PubMed

    Emtiaz, Shahram; Noroozi, Sohrab; Caramês, João; Fonseca, Luís

    2006-12-01

    Dental rehabilitation of partially or totally edentulous patients with dental implants has become common practice in the last few decades, with reliable long-term results. However, local conditions of edentulous alveolar ridges may be unfavorable for implant placement. Vertically deficient alveolar ridges, in particular, may have insufficient bone volume to hold implants of adequate dimensions, making implant placement difficult or impossible. To correct this situation, a variety of surgical procedures have been proposed, including onlay bone grafts, vertical guided bone regeneration, and alveolar distraction osteogenesis. Distraction osteogenesis is a biologic process of new bone formation between the surfaces of bone segments that are gradually separated by incremental traction. This process is initiated when a traction force is applied to the bone segments and continues as long as the callus tissues are stretched. This traction force, in turn, generates tension within the tissues that connect the bone segments, which stimulates new bone formation parallel to the vector of distraction. The aim of this article is to provide clinicians with the historical background of and biologic basis for the concept of distraction osteogenesis, which can be traced back to the 1800s. Finally, a clinical case is presented to demonstrate a step-by-step application of alveolar distraction osteogenesis as a treatment protocol in a partially edentulous ridge for improvement of esthetics. PMID:17243326

  19. Plate-guided distraction osteogenesis to recreate two-thirds of the mandible including symphysis.

    PubMed

    Mohammed-Ali, Ricardo I; Henry, Alastair M; Khurram, Syed A; Yousefpour, Afshin

    2012-12-01

    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. PMID:22726522

  20. DEVELOPMENT OF TENSILE STRENGTH DURING DISTRACTION OSTEOGENESIS IN A RAT MODEL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    These studies were designed to determine the reliability of in vitro tensile testing to measure the temporal development of regenerate bone strength in rats during limb lengthening (distraction osteogenesis, DO). External fixators were placed on the right tibiae of 36 virus-free, 400-450 g male Spr...

  1. Bilateral Distraction Osteogenesis of Vascularized Iliac Crest Free Flaps Used in Mandibular Reconstruction

    PubMed Central

    Subramaniam, Shiva S.; Vujcich, Nathan J.; Nastri, Alf L.

    2016-01-01

    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.

  2. Clinical Use of Deferoxamine in Distraction Osteogenesis of Irradiated Bone.

    PubMed

    Momeni, Arash; Rapp, Scott; Donneys, Alexis; Buchman, Steven R; Wan, Derrick C

    2016-06-01

    The deleterious effects of radiotherapy, including hypovascularity and hypocellularity, have made distraction of irradiated bones challenging. Animal studies, however, have demonstrated adjunctive measures such as the administration of deferoxamine to significantly improve bone regeneration across irradiated distraction gaps. In this report, the authors demonstrate, for the first time, enhanced bone formation following deferoxamine application in a patient following distraction of a previously irradiated maxilla. Computed tomography imaging of the pterygomaxillary buttress on the side of administration revealed significantly increased bone area and density relative to the contralateral buttress. This is the first presentation of clinical deferoxamine use to promote bone formation following irradiated bone distraction and highlights the promise for this adjunctive measure to make outcomes after distraction of irradiated bone more reliable. PMID:27171947

  3. Transpalatal distraction for the management of maxillary constriction in pediatric patients

    PubMed Central

    Adolphs, Nicolai; Ernst, Nicole; Hoffmeister, Bodo; Raguse, Jan-Dirk

    2015-01-01

    Context: The management of severe maxillary constriction can be challenging. For that purpose surgically assisted maxillary expansion by transpalatal distraction (TPD) can typically be recommended after skeletal maturity. However in selected cases bone borne transpalatal distraction devices can contribute to improve maxillary constriction considerably earlier already during mixed dentition. Aims: To assess the possibility of bone borne transpalatal distraction in pediatric patients. Settings and Design: Clinical paper. Materials and Methods: Since 2010 TPD has been applied to six pediatric patients during mixed dentition when severe maxillary constriction was present and conventional orthodontic widening has already failed. Individually selected devices (Surgitec, Belgium) were inserted in general anaesthesia and distraction was performed according to well known parameters. Results: Maxillary constriction could be improved in all six patients without any drawbacks by bone borne devices during mixed dentition. Skeletal conditions were obviously improved for subsequent orthodontic or orthognathic therapy without functional impairment. Follow-up is up to 36 months after device removal. Conclusions: Transpalatal Distraction is recommendable in selected pediatric patients if massive growth disturbance is present or has to be expected. TPD allows for individually adapted maxillary expansion by selection and positioning of appropriate devices in combination with intraoperative testing of maxillary movements and controlled bone removal. PMID:26389033

  4. Combined micro computed tomography and histology study of bone augmentation and distraction osteogenesis

    NASA Astrophysics Data System (ADS)

    Ilgenstein, Bernd; Deyhle, Hans; Jaquiery, Claude; Kunz, Christoph; Stalder, Anja; Stübinger, Stefan; Jundt, Gernot; Beckmann, Felix; Müller, Bert; Hieber, Simone E.

    2012-10-01

    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.

  5. Anterior maxillary segmental distraction in the treatment of severe maxillary hypoplasia secondary to cleft lip and palate

    PubMed Central

    Li, Hongliang; Dai, Jiewen; Si, Jiawen; Zhang, Jianfei; Wang, Minjiao; Shen, Steve Guofang; Yu, Hongbo

    2015-01-01

    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

  6. Craniofacial reconstruction by transport distraction osteogenesis: corticotomy versus osteotomy--an experimental study.

    PubMed

    Kramer, Franz-Josef; Mueller, Michal; Rahmstorf, Meike; Swennen, Gwen; Dempf, Rupert; Schierle, Hannes

    2004-07-01

    Transport osteogenesis is a modified technique of callus distraction appropriate for the reconstruction of extended osseous defects of long or flat bones. The aim of this study was to determine the regenerative potential of this technique related to the degree of mobilization of the transport segment. In 10 adult sheep, critically sized defects of the calvaria were treated by gradual movement of a transport segment consisting of calvarial bone. The transport segments were either corticotomized (n = 5) or osteotomized (n = 5). The latency period was 5 days; the rate of distraction was 1 mm/d, extended for approximately 40 days. The consolidation period was 28 days. Specimens were investigated by conventional radiography, computed tomography scans, immunofluorescence, and histological examination. In both groups, transport osteogenesis resulted in a complete closure of the defect. The volume and thickness of newly formed bone at the defect site did not differ significantly between the groups, nor did the extent of vascularization. Bone formation and remodeling occurred during the entire period of distraction and consolidation. Osteotomized transport segments became smaller during distraction, whereas the volume of corticotomized segments remained relatively constant. In conclusion, transport osteogenesis resulted in reliable closure of extended skull defects in adult organisms; corticotomy and osteotomy of the transport segment led to a similar extent of bone formation. PMID:15213530

  7. Comprehensive Review of Adipose Stem Cells and Their Implication in Distraction Osteogenesis and Bone Regeneration

    PubMed Central

    Morcos, Mina W.; Al-Jallad, Hadil; Hamdy, Reggie

    2015-01-01

    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

  8. Management of post midface distraction occlusal discrepancy using temporary anchorage devices in a cleft patient

    PubMed Central

    Koteswara Prasad, N. K.; Hussain, Syed Altaf; Chitharanjan, Arun B.; Murthy, Jyotsna

    2015-01-01

    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

  9. Differences in mandibular distraction osteogenesis after corticotomy and osteotomy

    PubMed Central

    Hu, J.; Li, J.; Wang, D.; Buckley, M. J.; Agarwal, S.

    2016-01-01

    Corticotomy or osteotomy was performed on opposing sides of the mandibles in 18 goats. A custom-made distractor was used to lengthen the mandible at a rate of 1 mm/day for 10 days (total 10 mm elongation). Six goats were sacrificed respectively at 2, 4 and 8 weeks after completion of distraction. The distracted calluses were harvested and processed for radiographic, histologic, and scanning electron microscopic evaluation as well as Ca/P ratio analysis. The regenerate bone in the corticotomy side showed more bone formation and earlier mineralization than in the osteotomy side. The results of this study suggest that preservation of intramedullary vessels is beneficial to bone regeneration following mandibular osteodistraction, and that performing corticotomy may be a simple but effective way to promote the maturity of the distracted callus and shorten the time for fixation. PMID:12102418

  10. Differences in mandibular distraction osteogenesis after corticotomy and osteotomy.

    PubMed

    Hu, J; Li, J; Wang, D; Buckley, M J; Agarwal, S

    2002-04-01

    Corticotomy or osteotomy was performed on opposing sides of the mandibles in 18 goats. A custom-made distractor was used to lengthen the mandible at a rate of 1 mm/day for 10 days (total 10 mm elongation). Six goats were sacrificed respectively at 2, 4 and 8 weeks after completion of distraction. The distracted calluses were harvested and processed for radiographic, histologic, and scanning electron microscopic evaluation as well as Ca/P ratio analysis. The regenerate bone in the corticotomy side showed more bone formation and earlier mineralization than in the osteotomy side. The results of this study suggest that preservation of intramedullary vessels is beneficial to bone regeneration following mandibular osteodistraction, and that performing corticotomy may be a simple but effective way to promote the maturity of the distracted callus and shorten the time for fixation. PMID:12102418

  11. Distraction osteogenesis of the sternum for thoracic expansion in a severe case of jeune syndrome: a preliminary report.

    PubMed

    Imai, Yoshimichi; Kitanishi, Ryuta; Saiki, Yoshikatsu; Takeda, Atsushi; Tachi, Masahiro

    2016-06-01

    Severe asphyxiating thoracic dystrophy (Jeune syndrome) is usually fatal. The authors used distraction osteogenesis in a severe case and achieved 45 mm distraction of the sternum and improvement in tidal volume, lung compliance, and mean airway pressure. PMID:27009488

  12. Development of a device for the delivery of agents to bone during distraction osteogenesis.

    PubMed

    Grayson, B H; Rowe, N M; Hollier, L H; Williams, J K; McCormick, S; Longaker, M T; McCarthy, J G

    2001-01-01

    Various agents have been theoretically and experimentally implicated as mediators of distraction osteogenesis (DO). The purpose of this study was to develop a vehicle for the potential delivery of these factors to the region of the distraction site in an attempt to manipulate this biologic process. Three adult mongrel dogs (12 months old) had oblique osteotomies performed bilaterally through the gonial regions. In group I, the external distracter was affixed to the right hemimandible of two dogs (n = 2 hemimandibles) with cannulated pins (external diameter = 1.5 mm; lumen diameter = 1.0 mm; length = 60 mm), whereas the distracter on the left was affixed with standard, noncannulated pins of the same dimensions. In group II, cannulated pins were used to affix the external distracter to both hemimandibles (n = 2 hemimandibles) of a dog. The devices were activated after a 5-day latency period and were lengthened at a rate of 1 mm/day for 20 days. During the distraction period, 0.1 ml/d of sterile india ink was injected into the cannulated pins, after which the sterile stylet was replaced. The activation protocol was followed by 28 days of fixation (consolidation period). The hemimandibles from group I underwent removal of soft tissues, acetone fixation, and gross examination/photography, whereas the hemimandibles from group II were prepared for histologic evaluation (whole mount, hematoxylin and eosin staining). All dogs survived to the end of the study and demonstrated successful DO without evidence of complications. Hemimandibles in group I displayed evidence of india ink on both the lingual and buccal cortex around the cannulated pin site, in the regenerate and on the neocortices of the distracted segment. Hemimandibles of group II showed histologic evidence of the india ink being deposited densely around the cannulated pin site and extending in a radial fashion around the pin site into the regenerate. This study demonstrates for the first time a vehicle device for

  13. The biology of distraction osteogenesis for correction of mandibular and craniomaxillofacial defects: A review

    PubMed Central

    Natu, Subodh Shankar; Ali, Iqbal; Alam, Sarwar; Giri, Kolli Yada; Agarwal, Anshita; Kulkarni, Vrishali Ajit

    2014-01-01

    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

  14. Automating skeletal expansion: An implant for distraction osteogenesis of the mandible

    PubMed Central

    Magill, John C.; Byl, Marten F.; Goldwaser, Batya; Papadaki, Maria; Kromann, Roger; Yates, Brent; Morency, Joseph R.; Kaban, Leonard B.; Troulis, Maria J.

    2010-01-01

    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

  15. Vascular Development during Distraction Osteogenesis Proceeds by Sequential Intramuscular Arteriogenesis Followed by Intraosteal Angiogenesis

    PubMed Central

    Morgan, Elise F.; Hussein, Amira I.; Al-Awadhi, Bader A.; Hogan, Daniel E.; Matsubara, Hidenori; Al-Alq, Zainab; Fitch, Jennifer; Andre, Billy; Hosur, Krutika; Gerstenfeld, Louis C.

    2012-01-01

    Vascular formation is intimately associated with bone formation during distraction osteogenesis (DO). While prior studies on this association have focused on vascular formation locally within the regenerate, we hypothesized that this vascular formation, as well as the resulting osteogenesis, rely heavily on the response of the vascular network in surrounding muscular compartments. To test this hypothesis, the spatiotemporal sequence of vascular formation was assessed in both muscular and osseous compartments in a murine model of DO and was compared to the progression of osteogenesis. Micro-computed tomography (μCT) scans were performed sequentially, before and after demineralization, on specimens containing contrast-enhanced vascular casts. Image registration and subtraction procedures were developed to examine the co-related, spatiotemporal patterns of vascular and osseous tissue formation. Immunohistochemistry was used to assess the contributory roles of arteriogenesis (formation of large vessels) and angiogenesis (formation of small vessels) to overall vessel formation. Mean vessel thickness showed an increasing trend during the period of active distraction (p=0.068), whereas vessel volume showed maximal increases during the consolidation period (p=0.009). The volume of mineralized tissue in the regenerate increased over time (p<0.039), was correlated with vessel volume (r=0.59; p=0.025), and occurred primarily during consolidation. Immunohistological data suggested that: 1) the period of active distraction was characterized primarily by arteriogenesis in the surrounding muscle; 2) during consolidation, angiogenesis predominated in the intraosteal region; 3) vessel formation proceeded from the surrounding muscle into the regenerate. These data show that formation of vascular tissue occurs in both muscular and osseous compartments during DO and that periods of intense osteogenesis are concurrent with those of angiogenesis. The results further suggest the

  16. Treatment of lateral open bite with vertical dentoalveolar distraction osteogenesis.

    PubMed

    Aras, Işıl; Olmez, Sultan; Akay, Mehmet Cemal; Oztürk, Veli Ozgen; Aras, Aynur

    2015-08-01

    The aim of this article is to describe the surgical, orthodontic, and periodontal treatment of an adult patient with a lateral open bite, anterior crowding, and gingival recession on the mandibular right lateral incisor. The lateral open bite, which resisted conventional mechanics, was successfully corrected by the combination of dento-osseous osteotomies and vertical alveolar distraction using orthodontic multibracket appliances in conjunction with nickel-titanium archwires and intermaxillary elastics. After the orthodontic treatment, the denuded root surface of the mandibular right lateral incisor was closed using a coronally advanced flap technique with platelet-rich fibrin. The results at the 2-year posttreatment follow-up were satisfactory from both the occlusal and the periodontal standpoints. PMID:26232841

  17. Histological evaluation of condylar hyperplasia model of rabbit following distraction osteogenesis of the condylar neck.

    PubMed

    Meng, Q; Chen, G; Long, X; Deng, M; Cai, H; Li, J

    2011-01-01

    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. PMID:20626572

  18. Distraction osteogenesis device to estimate the axial stiffness of the callus in Vivo.

    PubMed

    Mora-Macías, J; Reina-Romo, E; Domínguez, J

    2015-10-01

    Knowing the evolution of callus stiffness is very important in distraction osteogenesis and bone healing. It allows the characterization of the bone maturation process and the assessment of the moment to retire the fixator. A new distractor device that monitors the callus axial stiffness is presented in this study. It quantifies the callus stiffness during the bone transport process with some advantages over previous methods to assess stiffness during simple distraction and bone healing. This device avoids a misalignment between bone segments, uses real load conditions, monitors forces continuously, does not involve radiation for patients, and allows the study of the complete distraction process, i.e., the distraction and consolidation phases. The device was calibrated in vitro simulating different real bone load conditions depending on the stage of the process. The stiffness of the callus could be estimated for values between 4.2 N/mm and 9066.8 N/mm. The average relative error in measurements carried out in in vitro calibration tests was 7.8% during the distraction phase and 9.5% during the consolidation phase. These results improve the accuracy and increase the callus stiffness range of estimation with respect to other devices in the literature. In addition, the device was used successfully in vivo in a preliminary experiment. PMID:26320818

  19. Comparison of two protocols of periosteal distraction osteogenesis in a rabbit calvaria model.

    PubMed

    Saulacic, Nikola; Nakahara, Ken; Iizuka, Tateyuki; Haga-Tsujimura, Maiko; Hofstetter, Willy; Scolozzi, Paolo

    2016-08-01

    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. PMID:26036193

  20. Mouse Models in Orthopaedic Research: An Overview of Fracture, Marrow Ablation, and Distraction Osteogenesis

    PubMed Central

    Lybrand, Kyle; Bragdon, Beth; Gerstenfeld, Louis

    2015-01-01

    Three commonly used murine surgical models of bone healing (closed fracture with intramedullary fixation, distraction osteogenesis (DO), and marrow ablation by reaming) are presented. Detailed surgical protocols for each model are outlined. The nature of the regenerative processes and the types of research questions that may be addressed with these models are briefly outlined. The relative strengths and weaknesses of these models are compared to a number of other surgical models that are used to address similar research questions. Refer to our companion article for more detailed overview of the underlying biology of each model. PMID:25727199

  1. Advances in the Treatment of Syndromic Midface Hypoplasia Using Monobloc and Facial Bipartition Distraction Osteogenesis

    PubMed Central

    Kumar, Anand R.; Steinbacher, Derek

    2014-01-01

    Midface hypoplasia or retrusion remains a persistent feature of syndromic craniosynostosis years after successful treatment of the cranium. Although expansion of the cranial vault in infancy by traditional fronto-orbital advancement, posterior expansion, or both, can treat the immediate intracranial constriction, midface hypoplasia and its stigmata of exorbitism, sleep apnea, central face concavity, and malocclusion remain suboptimally treated. Initial enthusiasm for the procedures was tempered due to a high rate of infectious complications; timing and indications for surgery continue to stir controversy. During the last decade renewed interest with the monobloc and facial bipartition procedure using distraction osteogenesis with either an internal or external distraction system has decreased morbidity significantly. These procedures have re-emerged as powerful and comprehensive tools in the treatment of syndromic midface hypoplasia. PMID:26417208

  2. A new approach to repairing cleft palate and acquired palatal defects with distraction osteogenesis.

    PubMed

    Wang, D-Z; Chen, G; Liao, Y-M; Liu, S-G; Gao, Z-W; Hu, J; Li, J-H; Liao, C-H

    2006-08-01

    Cleft palate (CP) is one of the most common human congenital deformities, and acquired palate defects after trauma or tumour resection are also common. In this study, distraction osteogenesis (DO) for CP and other palatal bone defects was evaluated. Twenty cats were assigned randomly to 3 groups of (1) 15, (2) 3 and (3) 2 cats. In groups 1 and 2, a rectangular ostectomy, in the posterior of the palatal bone shelf, was performed in the sagittal axis to establish the CP defect model. At the same time, a pure titanium intraoral distractor was fixed to molar teeth with brackets and to the palatal bone shelf across the defect with titanium miniscrews bilaterally. Four weeks later, a secondary transport disc (TD) osteotomy was performed, and gradual DO treatment started at 0.4mm twice a day, after 6 days of latency. DO was performed until the TD reached the opposite margin over the gap in 5-6 days. Three cats each of group 1 were killed at 2, 4, 6, 8 and 12 weeks after completion of DO. In group 2, the bone and soft-tissue defects were untreated until death 6 weeks later. Group 3 cats (control) were killed after 6 weeks. The TD successfully recombined with the opposite palatal bone stump, and proportional expansion of the overlay mucoperiosteal flap was achieved. Intramembranous bone formation was revealed: parallel collagen bundles gradually deposited on new bone trabeculae while the proliferative osteoblasts produced bone matrix. The bone defect was finally reconstructed by de novo osteogenesis. The control group was observed to have no spontaneous repairing. These results suggest that the CP defect was reconstructed by osteogenesis in situ, and the soft tissues expanded simultaneously to achieve functional correction. The intraoral distractor provided both effective distraction and stability. PMID:16690250

  3. Three-dimensional computed tomographic evaluation of Le Fort III distraction osteogenesis with an external device in syndromic craniosynostosis.

    PubMed

    Wery, M F; Nada, R M; van der Meulen, J J; Wolvius, E B; Ongkosuwito, E M

    2015-03-01

    There is little anteroposterior growth of the midface in patients with syndromic craniosynostosis who are followed up over time without intervention. A Le Fort III with distraction osteogenesis can be done to correct this. This is a controlled way in which to achieve appreciable stable advancement of the midface without the need for bone grafting, but the vector of the movement is not always predictable. The purpose of this study was to evaluate the 3-dimensional effect of Le Fort III distraction osteogenesis with an external frame. Ten patients (aged 7-19 years) who had the procedure were included in the study. The le Fort III procedure and the placement of the external frame were followed by an activation period and then a 3-month retention period. Computed tomographic (CT) images taken before and after operation were converted and loaded into 3-dimensional image rendering software and compared with the aid of a paired sample t test and a colour-coded qualitative analysis. Comparison of the CT data before and after distraction indicated that the amount of midface advancement was significant. Le Fort III distraction osteogenesis is an effective way to advance the midface. However, the movement during osteogenesis is not always exactly in the intended direction, and a secondary operation is often necessary. Three-dimensional evaluation over a longer period of time is necessary. PMID:25605236

  4. Bilateral Mandibular Distraction Osteogenesis in the Neonate with Pierre Robin Sequence and Airway Obstruction: A Primary Option

    PubMed Central

    Zenha, Horácio; Azevedo, Luis; Rios, Leonor; Pereira, Alberto; Pinto, Armindo; Barroso, Maria Luz; Costa, Horácio

    2012-01-01

    Children with craniofacial abnormalities associated with retromicrognathia and glossoptosis often have compromised upper airway flow. In severe cases, emergency intubation is necessary immediately after birth, and tracheostomy is advocated to manage the airway in the neonatal period and to allow for feeding. Early intervention with bilateral mandibular osteogenesis avoids the need for tracheostomy, along with its complications, and it targets the primary etiologic factor of the problem—the anomalous anatomy of the mandible. We report two neonates with severe Pierre Robin sequence managed with bilateral mandibular distraction osteogenesis on day 9 and day 11 of life. The surgical techniques and distraction and consolidation periods were similar apart from the distraction devices used. The procedures were successful with early extubation (day 5 and day 7), oral feeding tolerance (day 11 and day 13) and hospital discharge (day 19 and day 18). Total mandibular distraction was 19 mm and 23.45 mm, respectively. No major complications were reported. Medium to long-term results were good. Bilateral mandibular distraction osteogenesis in the neonate is a safe and accurate procedure and is the primary option in cases of selected severe Pierre Robin sequence. PMID:23450076

  5. Effect of distraction osteogenesis of the mandible on upper airway volume and resistance in children with micrognathia.

    PubMed

    Perlyn, Chad A; Schmelzer, Rodney E; Sutera, Salvatore P; Kane, Alex A; Govier, Dan; Marsh, Jeffrey L

    2002-05-01

    Children with craniofacial anomalies often have compromise of the upper airway, a condition with potential for morbidity and mortality. In children with microretrognathia, the diminutive size and retruded position of the mandible reduces the size of the oropharynx, thereby predisposing to glossoptosis and airway obstruction. Although several authors have reported successful use of mandibular distraction osteogenesis to alleviate this type of upper airway obstruction, the physiologic relationship between changes in mandibular shape, size, and position and upper airway dynamics remains undefined. The purpose of this study was to develop methodologies to quantitatively evaluate upper airway dynamics in children with micrognathia both before and after mandibular distraction osteogenesis. The patient population consisted of four children with micrognathia who had successfully undergone upper airway stabilization by bilateral mandibular distraction osteogenesis. The data used were digitally archived computed tomographic scan data from high-resolution, thin-slice head computed tomographic scans obtained before and after mandibular distraction. Upper airway evaluation was performed in two ways: static and dynamic. Static analysis consisted of computer quantification of predistraction and postdistraction mandibular and upper airway volumes using Analyze imaging software. Dynamic analysis consisted of fabrication of rigid stereolithographic hollow cast models of the upper airway produced from computed tomographic scan data. Models were used for characterization of upper airway resistance and flow patterns as related to respiration. After distraction osteogenesis, mandibular total volume increased 32, 32, 18, and 25 percent (mean, 27 percent) and upper airway volume increased by 20, 31, 23, and 71 percent (mean, 37 percent). A significant decrease in flow resistance, both inspiratory and expiratory, was observed in the patient with the greatest upper airway volume increase

  6. Combined use of alveolar distraction osteogenesis and segmental osteotomy in anterior vertical ridge augmentation

    PubMed Central

    Öncü, Elif; Isik, Kubilay; Alaaddinoğlu, E. Emine; Uçkan, Sina

    2015-01-01

    Introduction Vertical defects of the anterioral veolar ridge are challenging cases in implant dentistry. Various techniques, such as onlay bone grafting, segmental osteotomy (SO) oral veolar distraction osteogenesis (ADO), have been suggested to manage those situations. ADO has an advantage of being capable of enhancing both hard and soft tissue simultaneously. Presentation of case One of the possible complications of ADO is rotation ortilting the transport segment (TS). In this report, we present a 30-year old woman who had a severe anterior vertical deficiency. ADO was started to manage the case, but advancement of the TS lagged on the left side and the segment rotated. A SO was planned and the lagged side was corrected. Two years after the surgery, hard and soft tissue gains were found to be preserved. Discussion Vertical alveolar bone deficiencies are challenging cases for dental implantology. Alveolar DO promotes soft tissue along with hard tissue, and the bone regeneration process and shows lower infection rates and greater stability over the long term. However, the technique has some disadvantages and can lead to complications, such as breaking of the distraction device, nerve injury or paresthesia, fracture of transport bone, hematoma, wound dehiscence, severe bleeding, and even jaw fractures. Deviation of the TS from the distraction path is another undesired situation. The rigidity of the device, the width of the mucosa, the volume of the transport and anchor segments, and the amount of augmentation can affect vector deviation. Conclusion We suggest that SO can be used in similar cases in which TS could not be distracted on a straight vector line. PMID:25661636

  7. Beneficial role of periosteum in distraction osteogenesis of mandible: its preservation prevents the external bone resorption.

    PubMed

    Takeuchi, Sawako; Matsuo, Akira; Chiba, Hiroshige

    2010-01-01

    Distraction osteogenesis (DO) is a surgical process of new bone generation through the gradual extension of two segments of existing bone. DO is applied for maxillofacial surgeries to manage defects in mandibular continuity. Vertical DO with an oral device is often employed to augment the alveolar bone height for better implant anchorage for esthetic purposes or functional prosthetic requirements. To determine how the periosteum affects the vertical DO in mandibular reconstruction, we extracted the teeth and resected the alveolar parts of the mandible on both sides of dogs, along with removal of the surrounding periosteum in the right, but not left side. Three months later, box-shaped bone segments (vectors) were prepared from the resected alveolar part, and the segments were vertically elongated using a distraction device on both sides at 0.9 mm/day for one week. The extent of bone formation after distraction was determined with micro-focused computed tomography and by measuring incorporation of tetracycline and calcein with confocal laser scanning microscopy. During the initial two months after distraction, new bone formation was observed more prominently in the left side than in the right side of mandible with the periosteum. However, this difference was less clear during the bone-remodeling period. One notable change was the reduced height of the alveolar part of the right-side mandible, a sign of external bone resorption, observed in two out of three dogs at 6-month post-consolidation. These findings suggest that preservation of periosteum prevents the external bone resorption during the vertical DO of mandible. PMID:20046054

  8. Temporo-spatial analysis of Osterix, HNK1 and Sox10 during odontogenesis and maxillaries osteogenesis.

    PubMed

    Tomazelli, Karin Berria; Modolo, Filipe; Trentin, Andrea Gonçalves; Garcez, Ricardo Castilho; Biz, Michelle Tillmann

    2015-10-01

    Cell differentiation is essential for maxillaries and tooth development. Facial mesenchymal tissue is formed by neural crest cells (NC). These cells are highly migratory, giving rise to various cell types, considered with a high level of plasticity, indicating that they contain progenitor cells with a great power of differentiation. In this study, it was analyzed the presence of NC cell progenitors and mesenchymal stem cells (MSC) during maxillaries osteogenesis and odontogenesis in rats. Histological slides were collected in two phases: embryonic age of 15 and 17 days; 2, 4 and 7 days after birth. Immunohistochemistry for MSC markers (Osterix) and NC cells (Sox10, HNK1) was performed. The results showed positive expression for Osterix and HNK1 in undifferentiated ectomesenchymal cells in early and late stages; Sox10 was present only in early stages in undifferentiated cells. All markers were present in differentiated cells. Although the experiments performed do not allow us to explain a possible role for Osx, HNK1 and Sox10 in both differentiated and undifferentiated cells during osteogenesis and odontogenesis, it had shown important results not yet described: the presence of HNK1 and Sox10 in osteoblasts and odontoblasts in late development stages and in the tooth germ epithelial cells and ameloblasts. PMID:26253417

  9. Nonvascularized Free Transport Distraction Osteogenesis to Reconstruct the Mandibular Defect of a Patient With an Ossifying Fibroma: A Case Report.

    PubMed

    Wang, Yan; Huang, Xuanping; Liang, Feixin; Zhou, Nuo

    2016-09-01

    We report on a case in which trifocal distraction osteogenesis was applied in a patient with a mandibular defect caused by resection of an ossifying fibroma. During the surgical procedure, we accidentally dissected the surrounding periosteal tissue of the left transport completely in the process of transport disc preparation and made the disc into a free bone graft. However, we still used this transport and successfully completed the distraction osteogenesis. The patient's facial and occlusal function were regained after treatment. PMID:27292526

  10. Secondary mandibular reconstruction after oral squamous cell carcinoma resection: clinical reevaluation of transport disk distraction osteogenesis.

    PubMed

    Seitz, Oliver; Harth, Marc; Ghanaati, Shahram; Lehnert, Thomas; Vogl, Thomas J; Sader, Robert; Klein, Cornelius M

    2010-01-01

    Besides bone grafting, transport disk distraction osteogenesis (TDDO) is an alternative approach that can be used for the reconstruction of the mandibular arch after neoplastic surgery. Although several animal experiments are reporting about the applicability of this technique, little is known about its long-term success in human beings. In this study, we report about the successful treatment of patients with defects of their mandibular arch due to tumor resection by means of the external bifocal TDDO. A total of 7 patients (n = 3 with lateral, n = 4 with anterior defects) were followed up for a mean period of 56 months. Although neither adjuvant nor neoadjuvant chemotherapy negatively influenced callus formation, prereconstructive radiation with a dose of 51 Gy led to an insufficient callus formation. The reconstruction of anterior defects was unsatisfying because tensions from the soft tissue on the fragile and rubber-like callus negatively influenced the natural arch shaping.In these cases, additional surgery was often required. However, reconstruction of lateral defects of the mandibular arch was more successful and resulted in functional bone with good quality, in which dental implants could be inserted. The results of this study emphasize that TDDO by means of bifocal distraction provides functional bone comparable to residual bone.Lateral defects of mandibular arch can be better reconstructed, whereas anterior defects often require additional surgery. PMID:20061975

  11. Distraction osteogenesis in the treatment of temporomandibular joint ankylosis with mandibular micrognathia

    PubMed Central

    Giraddi, Girish B.; Arora, Kirti; Sai Anusha, A. J.

    2016-01-01

    Aims: The aims of the study were to evaluate the efficacy of simultaneous interpositional arthroplasty with distraction osteogenesis (DO) as a single procedure and to give the patient acceptable functional rehabilitation with correction of the gross facial asymmetry. Materials and Methods: Nine patients of temporomandibular joint (TMJ) ankylosis with micrognathia were treated with interpositional arthroplasty and simultaneous DO and followed for a period of minimum 3 years. Preoperative, immediate postoperative, at the end of distraction, at 6 months and 3 years postdistraction consolidation radiographs were taken along with the clinical examination for mouth opening, deviation, length of the mandible and ramus, midline shift, occlusal cant, and occlusion. Results: The results showed an increase in the mouth opening, length of the mandible and ramus height, correction of deviation, occlusion, and midline shift. Relapse was not seen in any case, rather one patient developed infection at the distractor site and two patients had fracture of the roots of the teeth at the osteotomy site. There was an overall improvement in the facial asymmetry. Conclusion: Simultaneous interpositional arthroplasty with DO should be used to correct TMJ ankylosis associated with facial asymmetry/micrognathia, as it reduces the need for second surgery, thereby saving the trauma of a second surgery and difficulty in intubation, increases the length of the mandible, corrects the deformity, thereby resulting in an acceptable facial esthetics and function.

  12. Quantitative Histologic Evidence of Amifostine Induced Cytoprotection in an Irradiated Murine Model of Mandibular Distraction Osteogenesis

    PubMed Central

    Tchanque-Fossuo, Catherine N.; Donneys, Alexis; Razdolsky, Elizabeth R.; Monson, Laura; Farberg, Aaron S.; Deshpande, Sagar S.; Sarhaddi, Deniz; Poushanchi, Behdod; Goldstein, Steven A.; Buchman, Steven R.

    2012-01-01

    Background Head and neck cancer (HNC) management requires adjuvant radiation therapy (XRT). The authors have previously demonstrated the damaging effect of a human equivalent dose of radiation (HEDR) on a murine mandibular model of distraction osteogenesis (DO). Utilizing quantitative histomorphometry (QHM), our specific aim is to objectively measure the radio-protective effects of Amifostine (AMF) on the cellular integrity and tissue quality of an irradiated and distracted regenerate. Methods Sprague Dawley rats were randomly assigned into 2 groups: XRT/DO and AMF/XRT/DO, which received AMF prior to XRT. Both groups were given HEDR in 5 fractionated doses and underwent a left mandibular osteotomy with bilateral fixator placement. Distraction to 5.1mm was followed by a 28-day consolidation period. Left hemimandibles were harvested. QHM was performed for osteocyte count (Oc), empty lacunae (EL), Bone Volume/Tissue Volume (BV/TV) and Osteoid Volume/Tissue Volume (OV/TV) ratios. Results AMF/XRT/DO exhibited bony bridging as opposed to XRT/DO fibrous unions. QHM analysis revealed statistically significant higher Oc and BV/TV ratio in AMF-treated mandibles compared with irradiated mandibles. There was a corresponding decrease in EL and the ratio of OV/TV between AMF/XRT/DO and XRT/DO. Conclusion We have successfully established the significant osseous cytoprotective and histoprotective capacity of AMF on DO in the face of XRT. AMF-sparing effect on bone cellularity correlated with an increase in bony union and elimination of fibrous union. We posit that the demonstration of similar efficacy of AMF in the clinic may allow the successful implementation of DO as a viable reconstructive option for HNC in the future. PMID:22878481

  13. Sympathetic denervation-induced MSC mobilization in distraction osteogenesis associates with inhibition of MSC migration and osteogenesis by norepinephrine/adrb3.

    PubMed

    Du, Zhaojie; Wang, Lei; Zhao, Yinghua; Cao, Jian; Wang, Tao; Liu, Peng; Zhang, Yabo; Yang, Xinjie; Cheng, Xiaobing; Liu, Baolin; Lei, Delin

    2014-01-01

    The sympathetic nervous system regulates bone formation and resorption under physiological conditions. However, it is still unclear how the sympathetic nerves affect stem cell migration and differentiation in bone regeneration. Distraction osteogenesis is an ideal model of bone regeneration due to its special nature as a self-engineering tissue. In this study, a rat model of mandibular distraction osteogenesis with transection of cervical sympathetic trunk was used to demonstrate that sympathetic denervation can deplete norepinephrine (NE) in distraction-induced bone callus, down-regulate β3-adrenergic receptor (adrb3) in bone marrow mesenchymal stem cells (MSCs), and promote MSC migration from perivascular regions to bone-forming units. An in vitro Transwell assay was here used to demonstrate that NE can inhibit stroma-derived factor-1 (SDF-1)-induced MSC migration and expression of the migration-related gene matrix metalloproteinase-2 (MMP-2) and downregulate that of the anti-migration gene tissue inhibitor of metalloproteinase-3 (TIMP-3). Knockdown of adrb3 using siRNA abolishes inhibition of MSC migration. An in vitro osteogenic assay was used to show that NE can inhibit the formation of MSC bone nodules and expression of the osteogenic marker genes alkaline phosphatase (ALP), osteocalcin (OCN), and runt-related transcription factor-2 (RUNX2), but knockdown of adrb3 by siRNA can abolish such inhibition of the osteogenic differentiation of MSCs. It is here concluded that sympathetic denervation-induced MSC mobilization in rat mandibular distraction osteogenesis is associated with inhibition of MSC migration and osteogenic differentiation by NE/adrb3 in vitro. These findings may facilitate understanding of the relationship of MSC mobilization and sympathetic nervous system across a wide spectrum of tissue regeneration processes. PMID:25144690

  14. Surgical Management of Pierre Robin Sequence: Using Mandibular Distraction Osteogenesis to Address Hypoventilation and Failure to Thrive in Infancy.

    PubMed

    Scott, Andrew R

    2016-04-01

    Mandibular hypoplasia may present in isolation or in the context of glossoptosis and a U-shaped, incomplete cleft palate. This latter triad is referred to as Pierre Robin sequence. Deleterious effects of micrognathia that may present during infancy are due primarily to glossoptosis or posterior displacement of the tongue. This tongue base prolapse may cause varying degrees of upper airway obstruction. A surgical option for management of tongue base airway obstruction secondary to mandibular hypoplasia is neonatal mandibular distraction osteogenesis. Herein, the author seeks to outline the benefits and limitations of early mandibular distraction osteogenesis as a way of managing airway obstruction and feeding difficulty in newborns with micrognathia. A description of the author's operative technique as well as potential complications and pitfalls will also be discussed. PMID:27097139

  15. Adipose-derived stem cells transfected with pEGFP-OSX enhance bone formation during distraction osteogenesis.

    PubMed

    Lai, Qing-guo; Sun, Shao-long; Zhou, Xiao-hong; Zhang, Chen-ping; Yuan, Kui-feng; Yang, Zhong-jun; Luo, Sheng-lei; Tang, Xiao-peng; Ci, Jiang-bo

    2014-05-01

    This study was designed to investigate the effects of local delivery of adipose-derived stem cells (ADSCs) transfected with transcription factor osterix (OSX) on bone formation during distraction osteogenesis. New Zealand white rabbits (n=54) were randomly divided into three groups (18 rabbits per group). A directed cloning technique was used for the construction of recombinant plasmid pEGFP-OSX, where EGFP is the enhanced green fluorescence protein. After osteodistraction of the right mandible of all experimental rabbits, rabbits in group A were treated with ADSCs transfected with pEGFP-OSX, group B with ADSCs transfected with pEGFP-N1, and group C with physiological saline. Radiographic and histological examinations were processed after half of the animals within each group were humanely killed by injection of sodium pentothal at Week 2 or 6 after surgery. The distraction bone density was measured as its projectional bone mineral density (BMD). Three parameters were measured, namely, the thickness of new trabeculae (TNT), and the volumes of the newly generated cortical bone (NBV1) and the cancellous bone (NBV2) of the distracted regions. Good bone generation in the distraction areas was found in group A, which had the highest BMD, TNT, and NBV in the distraction zones among the groups. There was no significant difference in bone generation in the distraction areas between groups B and C. The results indicate that the transplantation of ADSCs transfected with pEGFP-OSX can effectively promote bone generation during distraction in vivo. PMID:24793766

  16. Direct bone formation during distraction osteogenesis does not require TNF alpha receptors and elevated serum TNF alpha fails to inhibit bone formation in TNFR1 deficient mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Distraction osteogenesis (DO) is a process which induces direct new bone formation as a result of mechanical distraction. Tumor necrosis factor-alpha (TNF) is a cytokine that can modulate osteoblastogenesis. The direct effects of TNF on direct bone formation in rodents are hypothetically mediated th...

  17. Histological and physical analysis of bone neoformation by osteogenesis distraction: A preliminary report

    PubMed Central

    Vannucci, Marcello Gaieta; Dreyer, Juliana; Kreisner, Paulo; Gaião, Leonilson; Moraes, João Feliz Duarte; de Oliveira, Marilia Gerhardt

    2011-01-01

    Introduction: Osteogenesis distraction (OD) is a mainstream technique in maxillofacial surgical reconstruction with varied applications. OD technique employs a distractor with the aim to get new bone in the site of interest. Osseous maturation time is necessary before the device can be removed and few patients’ complaint of related discomfort, especially when these devices are external, and induces superficial infections, paresthesia, hypertrophic scars and social relationship difficulties. The use of Low Level Laser Therapy (LLLT) has been proved beneficial to soft tissue and osseous repairs. Materials and Method: 12 rabbits were randomly divided in to two groups. In all animals, distractor was placed and one group was exposed to LLLT while the other group served as control. After consolidation, animals were sacrificed, the new bone formed were subjected to investigations including histomorphometric, physical analysis and tomographical analysis. Statistical analyses were performed using SPSS software. Result: Newly formed bone was significantly different between the groups. The physical properties of the neobone were comparatively better when the animals were exposed to LLLT with varying statistical significance. Conclusion: The results obtained with smaller sample size in this study need to be interpreted with care. The results of this preliminary pilot study encourage the use of LLLT during healing period. However the histological, tomographical and physical findings need to be ascertained using a larger sample size to study the bio-stimulatory effects with laser therapy from basics to clinical relevance on wound and bone healing. PMID:23482632

  18. Bilateral sagittal split osteotomy versus distraction osteogenesis of the mandible: a randomized clinical trial.

    PubMed

    Baas, E M; Bierenbroodspot, F; de Lange, J

    2015-02-01

    A randomized clinical trial was performed to evaluate differences in postoperative neurosensory disturbance (NSD) between two methods of mandibular advancement surgery. A total of 66 non-syndromal class II patients with mandibular hypoplasia were randomized for either distraction osteogenesis (DO) or bilateral sagittal split osteotomy (BSSO). Twenty-nine patients in the BSSO group and 34 patients in the DO group were available for evaluation. Objective assessment was performed by Semmes-Weinstein (SW) monofilament testing preoperatively and at least 1 year after surgery. Six of the 34 patients (17.6%) in the DO group experienced objective NSD, compared to 5/29 patients (17.2%) in the BSSO group. In the evaluation of nerve function by individual nerves, 8/68 nerves (11.8%) revealed objective NSD in the DO group, compared to 7/58 nerves (12.1%) in the BSSO group. A subjective NSD was reported in 11/34 patients (32.4%) in the DO group, compared to 9/29 patients (31.0%) in the BSSO group. In the evaluation of nerve function by individual nerves, a subjective NSD was reported for 13/68 nerves (19.1%) in the DO group, compared to 13/58 nerves (22.4%) in the BSSO group. None of the differences was significant. No differences in neurosensory disturbance could be found between the two study groups. Objective WS monofilament testing appeared to underestimate NSD compared to subjective patient report. PMID:25457820

  19. Severe proliferative congenital temporomandibular joint ankylosis: a proposed treatment protocol utilizing distraction osteogenesis.

    PubMed

    Bartlett, Scott P; Reid, Russell R; Losee, Joseph E; Quinn, Peter D

    2006-05-01

    The classical treatment for temporomandibular joint (TMJ) ankylosis in children: 1) joint release; 2) arthroplasty; 3) reconstruction; and 4) postoperative physical therapy (PT), is often unsuccessful. Postoperative physical therapy is difficult in the young patient due to poor cooperation. Moreover, there is a subgroup of patients who have a refractory congenital proliferative bony process that is the cause of their disease. In these patients, a role for distraction osteogenesis (DO) has been defined. We present a series of young patients with congenital proliferative TMJ ankylosis. Some have failed classic treatment. In such cases, DO is used to expand the mandibular size and soft tissue matrix. This creates a static open bite, facilitates mid-facial growth, and avoids compromise of the airway, speech, nutrition, and oral hygiene. To maintain these objectives, mandibular DO may be repeated as the child matures. Once skeletal maturity is reached, DO is used to normalize occlusion and further expand the soft tissue envelope prior to definitive reconstruction and aggressive post-op PT. In seven patients, this protocol has been used. Five patients are currently in the active phase of growth and undergoing interim treatment with mandibular DO. Two patients have reached skeletal maturity and have completed the protocol of DO with definitive arthroplasty and reconstruction. DO is a valuable aid in the treatment of the problematic child with congenital proliferative TMJ ankylosis. Interim DO, prior to definitive arthroplasty and reconstruction, can provide a static open bite that prevents progressive deformity and its associated functional disturbances. PMID:16770209

  20. Chronic ethanol exposure inhibits distraction osteogenesis in a mouse model: Role of the TNF signaling axis

    SciTech Connect

    Wahl, Elizabeth C.; Aronson, James; Liu, Lichu; Liu, Zhendong; Perrien, Daniel S.; Skinner, Robert A.; Badger, Thomas M.; Ronis, Martin J.J.; Lumpkin, Charles K. . E-mail: lumpkincharlesk@uams.edu

    2007-05-01

    Tumor necrosis factor-alpha (TNF-{alpha}) is an inflammatory cytokine that modulates osteoblastogenesis. In addition, the demonstrated inhibitory effects of chronic ethanol exposure on direct bone formation in rats are hypothetically mediated by TNF-{alpha} signaling. The effects in mice are unreported. Therefore, we hypothesized that in mice (1) administration of a soluble TNF receptor 1 derivative (sTNF-R1) would protect direct bone formation during chronic ethanol exposure, and (2) administration of recombinant mouse TNF-{alpha} (rmTNF-{alpha}) to ethanol naive mice would inhibit direct bone formation. We utilized a unique model of limb lengthening (distraction osteogenesis, DO) combined with liquid diets to measure chronic ethanol's effects on direct bone formation. Chronic ethanol exposure resulted in increased marrow TNF, IL-1, and CYP 2E1 RNA levels in ethanol-treated vs. control mice, while no significant weight differences were noted. Systemic administration of sTNF-R1 during DO (8.0 mg/kg/2 days) to chronic ethanol-exposed mice resulted in enhanced direct bone formation as measured radiologically and histologically. Systemic rmTNF-{alpha} (10 {mu}g/kg/day) administration decreased direct bone formation measures, while no significant weight differences were noted. We conclude that chronic ethanol-associated inhibition of direct bone formation is mediated to a significant extent by the TNF signaling axis in a mouse model.

  1. Amifostine Treatment Mitigates the Damaging Effects of Radiation on Distraction Osteogenesis in the Murine Mandible.

    PubMed

    Monson, Laura A; Nelson, Noah S; Donneys, Alexis; Farberg, Aaron S; Tchanque-Fossuo, Catherine N; Deshpande, Sagar S; Buchman, Steven R

    2016-08-01

    According to the American Society of Clinical Oncology, in 2012, more than 53,000 new cases of head and neck cancers (HNCs) were reported in the United States alone and nearly 12,000 deaths occurred relating to HNC. Although radiotherapy (XRT) has increased survival, the adverse effects can be unrelenting and their management is rarely remedial. Current treatment dictates surgical mandibular reconstruction using free tissue transfer. These complex operations entail extended hospitalizations and attendant complications often lead to delays in initiation of adjuvant therapy, jeopardizing prognosis as well as quality of life. The creation of new bone by distraction osteogenesis (DO) generates a replacement of deficient tissue from local substrate and could have immense potential therapeutic ramifications. Radiotherapy drastically impairs bone healing, precluding its use as a reconstructive method for HNC. We posit that the deleterious effects of XRT on bone formation could be pharmacologically mitigated. To test this hypothesis, we used a rodent model of DO and treated with amifostine, a radioprotectant, to assuage the XRT-induced injury on new bone formation. Amifostine had a profound salutary effect on bone regeneration, allowing the successful implementation of DO as a reconstructive technique. The optimization of bone regeneration in the irradiated mandible has immense potential for translation from the bench to the bedside, providing improved therapeutic options for patients subjected to XRT. PMID:27070667

  2. BONE REGENERATION AND DOCKING SITE HEALING AFTER BONE TRANSPORT DISTRACTION OSTEOGENESIS IN THE CANINE MANDIBLE

    PubMed Central

    Nagashima, Lucy K; Newby, Michelle Rondon; Zakhary, Ibrahim E; Nagy, William W; Zapata, Uriel; Dechow, Paul C; Opperman, Lynne A; Elsalanty, Mohammed E

    2011-01-01

    Purpose Bone transport distraction osteogenesis (BTDO) provides a promising alternative to traditional grafting techniques. However, existing BTDO devices have many limitations. The purpose of this research was to test a new device, the mandibular bone transport reconstruction plate (BTRP), in an animal model with comparable mandible size to humans and to histologically and mechanically examine the regenerate bone. Materials and methods Eleven adult foxhound dogs were divided into an unreconstructed control group of 5 animals, and an experimental group of 6 animals. In each animal, a 34 mm segmental defect was created in the mandible. The defect was reconstructed with BTRP. Histological and biomechanical characteristics of the regenerate and un-repaired defect were analyzed and compared to bone on the contralateral side of the mandible after 4 weeks of consolidation. Results The reconstructed defect was bridged with new bone, with little bone in the control defect. Regenerate density and microhardness were 22.3% and 42.6% lower than the contralateral normal bone, respectively. Likewise, the anisotropy of the experimental group was statistically lower than in the contralateral bone. Half the experimental animals showed non-union at the docking site. Conclusion The device was very stable and easy to install and activate. After one month of consolidation, the defect has been bridged with new bone with evidence of active bone formation. Regenerate bone was less mature than the control bone. Studies are underway to identify when the regenerate properties compare to normal bone, and to identify methods to augment bone union at the docking site. PMID:21601342

  3. Treatment of large bone defects with a novel biological transport disc in non-vascular transport distraction osteogenesis.

    PubMed

    Zeng, J J; Guo, P; Zhou, N; Xie, Q T; Liao, F C

    2016-05-01

    The aim of this study was to investigate a potential novel biological transport disc that avoids secondary injury to the body and facilitates bone healing. Twenty-seven dogs were divided randomly into three groups: group A were treated with human bone morphogenetic protein 2 (BMP-2) modified bone mesenchymal stem cell (BMSC) sheets combined with freeze-dried bone allograft as biological transport disc; group B were treated with BMSC sheets combined with freeze-dried bone allograft as transport disc (control); and group C were treated with direct extension only (blank). There were nine dogs in each group. Non-vascular transport distraction osteogenesis was performed in groups A and B to repair the mandibular bone defects, and in group C only mandibular truncation surgery was performed. The regeneration of bone was evaluated through X-ray, haematoxylin and eosin assay, and immunohistochemistry. After 2, 4, and 8 weeks of distraction, new bone density values in group A were 49.00±1.16, 66.63±2.62, and 72.78±2.67, respectively, and these were significantly different to values in groups B (P=0.0005, P=0.0004, P=0.0012) and C (P<0.0005, P=0.0001, P=0.0003). The average grey value for BMP-2 expression in group A after 4 weeks of distraction was 195.63±4.45, which was significantly different when compared to groups B (P=0.0022) and C (P=0.0006). This novel biological transport disc represents an effective non-secondary injury method to enhance new bone formation in non-vascular transport distraction osteogenesis. PMID:26792145

  4. Vascular Analysis as a Proxy for Mechanostransduction Response in an Isogenic, Irradiated Murine Model of Mandibular Distraction Osteogenesis

    PubMed Central

    Deshpande, Sagar S.; Donneys, Alexis; Kang, Steven Y.; Page, Erin E.; Felice, Peter A.; Kiryakoza, Lauren; Nelson, Noah S.; Rodriguez, Jose L; Deshpande, Samir S.; Buchman, Steven R

    2014-01-01

    Introduction Head and neck cancer is a debilitating and disfiguring disease. Although numerous treatment options exist, an array of debilitating side effects accompany them, causing physiological and social problems. Distraction osteogenesis (DO) can avoid many of the pathologies of current reconstructive strategies; however, due to the deleterious effects of radiation on bone vascularity, DO is generally ineffective. This makes investigating the effects of radiation on neovasculature during DO and creating quantifiable metrics to gauge the success of future therapies vital. The purpose of this study was to develop a novel isogenic rat model of impaired vasculogenesis of the regenerate mandible in order to determine quantifiable metrics of vascular injury and associated damage. Methods Male Lewis Rats were divided into two groups: DO only (n=5) AND Radiation Therapy (XRT) + DO (n=7). Afterwards, a distraction device was surgically implanted into the mandible. Finally, they were distracted a total of 5.1mm. Animals were perfused with a radiopaque casting agent concomitant with euthanasia, and subsequently demineralization, microcomputed tomography, and vascular analysis were performed. Results Vessel Volume Fraction, Vessel Thickness, Vessel Number, and Degree of Anisotropy were diminished by radiation. Vessel Separation was increased by radiation. Conclusion The DO group experienced vigorous vessel formation during distraction and neovascularization with a clear, directional progression, while the XRT/DO group saw weak vessel formation during distraction and neovascularization. Further studies are warranted to more deeply examine the impairments in osteogenic mechanotransductive pathways following radiation in the murine mandible. This isogenic model provides quantifiable metrics for future studies requiring a controlled approach to immunogenicity. PMID:25173587

  5. The effects of hypoxia-inducible factor (HIF)-1α protein on bone regeneration during distraction osteogenesis: an animal study.

    PubMed

    Jiang, X; Zhang, Y; Fan, X; Deng, X; Zhu, Y; Li, F

    2016-02-01

    The aim of this study was to observe the effect of hypoxia-inducible factor (HIF)-1α on bone regeneration during distraction osteogenesis (DO). Fifty-one New Zealand white rabbits underwent mandibular lengthening with a distraction rate of 2mm/day, and were divided randomly into three groups (17 in each). Group C rabbits received 20 μg rHIF-1α, group B received 10 μg rHIF-1α, and group A received 100 μl saline injection in the distraction gap every day for 10 days. Radionuclide bone imaging (RBI), computed tomography, dual energy X-ray absorptiometry, radiography, histology, and three-point bend testing were performed. RBI showed that the uptake ratio in group B (1.41 ± 0.25, P=0.013) and group C (1.64 ± 0.37, P<0.001) was higher than that in group A (1.01 ± 0.26). The bone mineralization density and bone mineralization content in group C were highest among the three groups. Radiology and histology findings indicated more callus regeneration in groups C and B. Mechanical testing demonstrated that the ultimate force in group C (289.71 ± 43.31N, n=6) was 1.49-fold (P<0.001) that of group A and 1.20-fold (P=0.012) that of group B. HIF-1α may represent a new agent to promote DO by accelerating osteogenesis and mineralization. PMID:26508376

  6. Initial Experience With a New Intraoral Midface Distraction Device

    PubMed Central

    Burstein, Fernando; Soldanska, Magdalena; Granger, Michael; Berhane, ChiChi; Schoemann, Mark

    2015-01-01

    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

  7. Demineralized Bone Matrix Injection in Consolidation Phase Enhances Bone Regeneration in Distraction Osteogenesis via Endochondral Bone Formation

    PubMed Central

    Kim, Ji-Beom; Seo, Sang Gyo; Kim, Eo Jin; Kim, Ji Hye; Yoo, Won Joon; Cho, Tae-Joon; Choi, In Ho

    2015-01-01

    Background Distraction osteogenesis (DO) is a promising tool for bone and tissue regeneration. However, prolonged healing time remains a major problem. Various materials including cells, cytokines, and growth factors have been used in an attempt to enhance bone formation. We examined the effect of percutaneous injection of demineralized bone matrix (DBM) during the consolidation phase on bone regeneration after distraction. Methods The immature rabbit tibial DO model (20 mm length-gain) was used. Twenty-eight animals received DBM 100 mg percutaneously at the end of distraction. Another 22 animals were left without further procedure (control). Plain radiographs were taken every week. Postmortem bone dual-energy X-ray absorptiometry and micro-computed tomography (micro-CT) studies were performed at the third and sixth weeks of the consolidation period and histological analysis was performed. Results The regenerate bone mineral density was higher in the DBM group when compared with that in the saline injection control group at the third week postdistraction. Quantitative analysis using micro-CT revealed larger trabecular bone volume, higher trabecular number, and less trabecular separation in the DBM group than in the saline injection control group. Cross-sectional area and cortical thickness at the sixth week postdistraction, assessed using micro-CT, were greater in the regenerates of the DBM group compared with the control group. Histological evaluation revealed higher trabecular bone volume and trabecular number in the regenerate of the DBM group. New bone formation was apparently enhanced, via endochondral ossification, at the site and in the vicinity of the injected DBM. DBM was absorbed slowly, but it remained until the sixth postoperative week after injection. Conclusions DBM administration into the distraction gap at the end of the distraction period resulted in a significantly greater regenerate bone area, trabecular number, and cortical thickness in the

  8. Parathyroid hormone PTH(1–34) increases the volume, mineral content, and mechanical properties of regenerated mineralizing tissue after distraction osteogenesis in rabbits

    PubMed Central

    2009-01-01

    Background and purpose Parathyroid hormone (PTH) has attracted considerable interest as a bone anabolic agent. Recently, it has been suggested that PTH can also enhance bone repair after fracture and distraction osteogenesis. We analyzed bone density and strength of the newly regenerated mineralized tissue after intermittent treatment with PTH in rabbits, which undergo Haversian bone remodeling similar to that in humans. Methods 72 New Zealand White rabbits underwent tibial mid-diaphyseal osteotomy and the callus was distracted 1 mm/day for 10 days. The rabbits were divided into 3 groups, which received injections of PTH 25 µg/kg/day for 30 days, saline for 10 days and PTH 25 µg/kg/day for 20 days, or saline for 30 days. At the end of the study, the rabbits were killed and the bone density was evaluated with DEXA. The mechanical bone strength was determined by use of a 3-point bending test. Results In the 2 PTH-treated groups the regenerate callus ultimate load was 33% and 30% higher, absorbed energy was 100% and 65% higher, BMC was 61% and 60% higher, and callus tissue volume was 179% and 197% higher than for the control group. Interpretation We found that treatment with PTH during distraction osteogenesis resulted in substantially higher mineralized tissue volume, mineral content, and bending strength. This suggests that treatment with PTH may benefit new bone formation during distraction osteogenesis and could form a basis for clinical application of this therapy in humans. PMID:19995322

  9. Mesenchymal stem cells modified with nerve growth factor improve recovery of the inferior alveolar nerve after mandibular distraction osteogenesis in rabbits.

    PubMed

    Wang, L; Zhao, Y; Cao, J; Yang, X; Lei, D

    2015-03-01

    Distraction osteogenesis is widely used in the treatment of bony deformities and defects. However, injury to the inferior alveolar nerve is a concern. Our aim was to investigate the feasibility of using lentiviral-mediated human nerve growth factor beta (hNGFβ) of the inferior alveolar nerve in mandibular distraction osteogenesis in rabbits. To achieve this, mesenchymal stem cells (MSC) from the bone marrow of rabbit mandibles were isolated and genetically engineered using recombinant lentiviral vector containing hNGFβ. Twenty New Zealand white rabbits underwent mandibular distraction osteogenesis, and 5 million MSC transduced with hNGFβ-vector or control vector were transplanted around the nerve in the gap where the bone had been fractured during the operation (n=10 in each group). After gradual distraction, samples of the nerve were harvested for histological and histomorphometric analysis. We found that the genetically engineered MSC transduced by the lentiviral vector were able to secrete hNGFβ at physiologically relevant concentrations as measured by ELISA. Histological examination of the nerve showed more regenerating nerve fibres and less myelin debris in the group in which hNGFβ-modified MSC had been implanted than in the control group. Histomorphometric analysis of the nerve showed increased density of myelinated fibres in the group in which hNGFβ-modified MSC had been implanted than in the control group. The data suggest that implantation of hNGFβ-modified MSC can accelerate the morphological recovery of the inferior alveolar nerve during mandibular distraction osteogenesis in rabbits. The use of lentiviral-mediated gene treatment to deliver hNGFβ through MSC may be a promising way of minimising injury to the nerve. PMID:25600702

  10. Effect of unilateral mandibular distraction osteogenesis on mandibular morphology in rabbits with antigen-induced temporomandibular joint arthritis.

    PubMed

    Andersen, K; Pedersen, T K; Svendsen, P; Hauge, E M; Schou, S; Nørholt, S E

    2015-08-01

    Aim was to evaluate effect of unilateral distraction osteogenesis (DO) on mandibular morphology in rabbits with antigen-induced arthritis in the temporomandibular joint (TMJ). Forty 8-week-old rabbits were divided into four groups. In groups A,C, arthritis was induced in the right TMJ. Groups A,B underwent DO. Group D served as control group. Cephalometric analysis of mandibular angle, mandibular ramus height, mandibular collum height, and total posterior mandibular height was done on CT-scans preoperatively (T0), after distraction (T1), and at euthanasia (T2). Two-factor ANOVA evaluated the effect of DO and antigen-induced arthritis. No effect of DO or arthritis was observed on mandibular angle or mandibular collum height. For T0-T1, DO increased mandibular ramus height 12.3% (95% CI 5.2-19.4%) in group B (P=0.001) and total posterior mandibular height 6.2% (95% CI 0.3-12.1%) in group A (P=0.04) and 10.0% (95% CI 4.3-15.7%) in group B (P=0.001). For T1-T2, no significant changes occurred in arthritic rabbits (group A). In conclusion, DO increased total posterior mandibular height in rabbits with arthritis. Postoperatively, no significant effect of DO was observed in rabbits with arthritis. Mandibular DO could be a viable treatment modality in patients with TMJ-arthritis. PMID:25835759

  11. Recombinant human bone morphogenetic protein-2 suspended in fibrin glue enhances bone formation during distraction osteogenesis in rabbits

    PubMed Central

    Li, Yunfeng; Li, Rui; Hu, Jing; Song, Donghui; Jiang, Xiaowen

    2016-01-01

    Introduction Bone morphogenetic protein-2 (BMP-2) has high potential for bone formation, but its in vivo effects are unpredictable due to the short life time. This study was designed to evaluate the effects of recombinant human (rh) BMP-2 suspended in fibrin on bone formation during distraction osteogenesis (DO) in rabbits. Material and methods The in vitro release kinetics of rhBMP-2 suspended in fibrin was tested using an enzyme-linked immunosorbent assay. Unilateral tibial lengthening for 10 mm was achieved in 48 rabbits. At the completion of osteodistraction, vehicle, fibrin, rhBMP-2 or rhBMP-2 suspended in fibrin (rhBMP-2 + fibrin) was injected into the center of the lengthened gap, with 12 animals in each group. Eight weeks later, the distracted callus was examined by histology, micro-CT and biomechanical testing. Radiographs of the distracted tibiae were taken at both 4 and 8 weeks after drug treatment. Results It was found that fibrin prolonged the life span of rhBMP-2 in vitro with sustained release during 17 days. The rhBMP-2 + fibrin treated animals showed the best results in bone mineral density, bone volume fraction, cortical bone thickness by micro-CT evaluation and mechanical properties by the three-point bending test when compared to the other groups (p < 0.05). In histological images, rhBMP-2 + fibrin treatment showed increased callus formation and better gap bridging compared to the other groups. Conclusions The results of this study suggest that fibrin holds promise to be a good carrier of rhBMP-2, and rhBMP-2 suspended in fibrin showed a stronger promoting effect on bone formation during DO in rabbits. PMID:27279839

  12. Treatment of Complications after Distraction Osteogenesis for Brachymetatarsia of the Fourth Metatarsal.

    PubMed

    Hamada, Mariko; Sakamoto, Yoshiaki; Nagasao, Tomohisa; Kishi, Kazuo

    2016-07-01

    Congenital brachymetatarsia most commonly involves the fourth ray and may be combined with metacarpal shortening. Numerous reports have demonstrated the usefulness of gradual lengthening of the metatarsals. However, very few studies have investigated methods of recovering the lost regenerative bone. The patient was a 16-year-old girl with bilateral brachymetatarsia of the fourth metatarsal. After a long consolidation period after gradual lengthening of the fourth metatarsal by 20 mm, the patient had an hourglass-shaped regenerated bone. Therefore, we grafted a bioabsorbable hydroxyapatite and collagen composite. Six months after the surgery, well-regenerated bone could be recognized on radiographic evaluation and was resistant to refracture. Callus distraction is a method that aims to avoid donor site morbidity. The strength of artificial bone is often a problem. Bioabsorbable hydroxyapatite and collagen composite compensates for the lack of regenerated bone and distraction gap and prevents refracture, thus preventing complications after metatarsal distraction. PMID:27536496

  13. Treatment of Complications after Distraction Osteogenesis for Brachymetatarsia of the Fourth Metatarsal

    PubMed Central

    Hamada, Mariko; Nagasao, Tomohisa; Kishi, Kazuo

    2016-01-01

    Summary: Congenital brachymetatarsia most commonly involves the fourth ray and may be combined with metacarpal shortening. Numerous reports have demonstrated the usefulness of gradual lengthening of the metatarsals. However, very few studies have investigated methods of recovering the lost regenerative bone. The patient was a 16-year-old girl with bilateral brachymetatarsia of the fourth metatarsal. After a long consolidation period after gradual lengthening of the fourth metatarsal by 20 mm, the patient had an hourglass-shaped regenerated bone. Therefore, we grafted a bioabsorbable hydroxyapatite and collagen composite. Six months after the surgery, well-regenerated bone could be recognized on radiographic evaluation and was resistant to refracture. Callus distraction is a method that aims to avoid donor site morbidity. The strength of artificial bone is often a problem. Bioabsorbable hydroxyapatite and collagen composite compensates for the lack of regenerated bone and distraction gap and prevents refracture, thus preventing complications after metatarsal distraction.

  14. The effect of transforming growth factor beta1 (TGF-beta1) on the regenerate bone in distraction osteogenesis.

    PubMed

    Ozkan, Korhan; Eralp, Levent; Kocaoglu, Mehmet; Ahishali, Bulent; Bilgic, Bilge; Mutlu, Zihni; Turker, Mehmet; Ozkan, Feyza Unlu; Sahin, Kemal; Guven, Melih

    2007-04-01

    Distraction osteogenesis is a well established clinical treatment for limb length discrepancy and skeletal deformities. Transforming growth factor beta 1 (TGF-beta1) is a multifunctional peptide which controls proliferation and expression of cells specific to bone like chondrocytes, osteoblasts, osteoclasts including mesenchymal precursor cells. To decrease the external fixation time with increasing the strength of regenerate (newly formed bone after distraction) we tested the effect of locally applied transforming growth factor beta 1 on distraction osteogenesis. A total of 28 mature female white New zealand rabbits weighing 3,5 kg-4,5 kg were studied. 10 animals were belonging to biomechanical testing group (5 for the study and 5 for the control subgroups), and the others were to histology group. In biomechanical group after tibial osteotomy TGF-beta1 was applied subperiosteally for 5 days just proximal to osteotomy site. Control group received only the solvent. Seven days after tibial osteotomy distraction was started at a rate of 0.25 mm/12 hours for 3 weeks with a unilateral fixator. Rabbits were sacrificed at the end of a consolidation period 8 week after tibial osteotomy. We assessed density of the elongation zone of rabbit tibial bones with the computed tomography. Then biomechanical parametres were assessed using the torsional testing using the material testing machine. In histology group rabbits were classified as control and study (rabbits that were given TGF-beta1). Rabbits were sacrificed at the end of first week, second week and fourth week also at the end of consolidation period 8 week after tibial osteotomy. Immunohistochemical and histologic parameters were examined. Biomechanical testing was applied as torsional testing. These values are used in determination of maximal loading, stiffness and energy absorbed during testing (brittleness). The histomorphometric examination looked for the differences between the study and control groups in terms of

  15. Scaffold-Based Delivery of Autologous Mesenchymal Stem Cells for Mandibular Distraction Osteogenesis: Preliminary Studies in a Porcine Model

    PubMed Central

    Sun, Zongyang; Tee, Boon Ching; Kennedy, Kelly S.; Kennedy, Patrick M.; Kim, Do-Gyoon; Mallery, Susan R.; Fields, Henry W.

    2013-01-01

    Purpose Bone regeneration through distraction osteogenesis (DO) is promising but remarkably slow. To accelerate it, autologous mesenchymal stem cells have been directly injected to the distraction site in a few recent studies. Compared to direct injection, a scaffold-based method can provide earlier cell delivery with potentially better controlled cell distribution and retention. This pilot project investigated a scaffold-based cell-delivery approach in a porcine mandibular DO model. Materials and Methods Eleven adolescent domestic pigs were used for two major sets of studies. The in-vitro set established methodologies to: aspirate bone marrow from the tibia; isolate, characterize and expand bone marrow-derived mesenchymal stem cells (BM-MSCs); enhance BM-MSC osteogenic differentiation using FGF-2; and confirm cell integration with a gelatin-based Gelfoam scaffold. The in-vivo set transplanted autologous stem cells into the mandibular distraction sites using Gelfoam scaffolds; completed a standard DO-course and assessed bone regeneration by macroscopic, radiographic and histological methods. Repeated-measure ANOVAs and t-tests were used for statistical analyses. Results From aspirated bone marrow, multi-potent, heterogeneous BM-MSCs purified from hematopoietic stem cell contamination were obtained. FGF-2 significantly enhanced pig BM-MSC osteogenic differentiation and proliferation, with 5 ng/ml determined as the optimal dosage. Pig BM-MSCs integrated readily with Gelfoam and maintained viability and proliferative ability. After integration with Gelfoam scaffolds, 2.4–5.8×107 autologous BM-MSCs (undifferentiated or differentiated) were transplanted to each experimental DO site. Among 8 evaluable DO sites included in the final analyses, the experimental DO sites demonstrated less interfragmentary mobility, more advanced gap obliteration, higher mineral content and faster mineral apposition than the control sites, and all transplanted scaffolds were completely

  16. Bone marrow stem cells assuage radiation-induced damage in a murine model of distraction osteogenesis: A histomorphometric evaluation.

    PubMed

    Zheutlin, Alexander R; Deshpande, Sagar S; Nelson, Noah S; Kang, Stephen Y; Gallagher, Kathleen K; Polyatskaya, Yekaterina; Rodriguez, Jose J; Donneys, Alexis; Ranganathan, Kavitha; Buchman, Steven R

    2016-05-01

    The purpose of this study is to determine if intraoperatively placed bone marrow stem cells (BMSCs) will permit successful osteocyte and mature bone regeneration in an isogenic murine model of distraction osteogenesis (DO) following radiation therapy (XRT). Lewis rats were split into three groups, DO only (Control), XRT followed by DO (xDO) and XRT followed by DO with intraoperatively placed BMSCs (xDO-BMSC). Coronal sections from the distraction site were obtained, stained and analyzed via statistical analysis with analysis of variance (ANOVA) and subsequent Tukey or Games-Howell post-hoc tests. Comparison of the xDO-BMSC and xDO groups demonstrated significantly improved osteocyte count (87.15 ± 10.19 vs. 67.88 ± 15.38, P = 0.00), and empty lacunae number (2.18 ± 0.79 vs 12.34 ± 6.61, P = 0.00). Quantitative analysis revealed a significant decrease in immature osteoid volume relative to total volume (P = 0.00) and improved the ratio of mature woven bone to immature osteoid (P = 0.02) in the xDO-BMSC compared with the xDO group. No significant differences were found between the Control and xDO-BMSC groups. In an isogenic murine model of DO, BMSC therapy assuaged XRT-induced cellular depletion, resulting in a significant improvement in histological and histomorphometric outcomes. PMID:27059203

  17. Mandibular distraction osteogenesis for the management of upper airway obstruction in children with micrognathia: a systematic review.

    PubMed

    Breik, O; Tivey, D; Umapathysivam, K; Anderson, P

    2016-06-01

    Mandibular distraction osteogenesis (MDO) is increasingly used for neonates and infants with upper airway obstruction secondary to micrognathia. This systematic review was conducted to determine the effectiveness of MDO in the treatment of airway obstruction. The databases searched included PubMed, Embase, Scopus, and grey literature sources. The inclusion criteria were applied to identify studies in children with clinical evidence of micrognathia/Pierre Robin sequence (PRS) who had failed conservative treatments, including both syndromic and non-syndromic patients. Overall 66 studies were included in this review. Primary MDO for the relief of upper airway obstruction was found to be successful at preventing tracheostomy in 95% of cases. Syndromic patients were found to have a four times greater odds of failure compared to those with isolated PRS. The most common causes of failure were previously undiagnosed lower airway obstruction, central apnoea, undiagnosed neurological abnormalities, and the presence of additional cardiovascular co-morbidities. MDO was less effective (81% success rate) at facilitating decannulation of tracheostomy-dependent children (P<0.0001). Failure in these patients was most commonly due to severe preoperative gastro-oesophageal reflux disease, swallowing dysfunction, and tracheostomy-related complications. The failure rate was higher when MDO was performed at an age of ≥24 months. More studies are needed to evaluate the long-term implications of MDO on facial development and long-term complications. PMID:26867668

  18. Skeletal stability after bilateral sagittal split osteotomy or distraction osteogenesis of the mandible: a randomized clinical trial.

    PubMed

    Baas, E M; Bierenbroodspot, F; de Lange, J

    2015-05-01

    A randomized clinical trial was carried out to evaluate postoperative stability after mandibular advancements in non-syndromal class II patients with a bilateral sagittal split osteotomy (BSSO) or distraction osteogenesis (DO). In total 32 patients could be included in the BSSO group and 34 patients in the DO group. The BSSO was converted to a unilateral procedure for one patient, and two patients in the BSSO group were lost during follow-up. A total 63 patients could be evaluated, 29 in the BSSO group and 34 in the DO group. Advancement was comparable in the two groups (mean 7.2mm). The mean follow-up period was 23.8 months (range 11-50 months). Lateral cephalograms were hand-traced. Horizontal relapse was measured in Y-B (mm) and SNB (°). For DO this was -0.324 mm and -0.250°, and for BSSO this was -0.448 mm and -0.259°, respectively (both not significant; NS). Vertical relapse measured in X-B was -0.074 mm for DO and -0.034 mm for BSSO (NS). The magnitude of advancement, a high mandibular plane angle, age and gender were not identified as independent risk factors for relapse. In conclusion, a BSSO and DO gave both similar stable results in advancements of the mandible up to 10mm. PMID:25595452

  19. Neonatal Mandibular Distraction Osteogenesis Reduces Cleft Palate Width and Lengthens Soft Palate, Influencing Palatoplasty in Patients With Pierre Robin Sequence.

    PubMed

    Collares, Marcus V M; Duarte, Daniele W; Sobral, Davi S; Portinho, Ciro P; Faller, Gustavo J; Fraga, Mariana M

    2016-07-01

    The aim of this study was to evaluate the influence of neonatal mandibular distraction osteogenesis (MDO) on cleft dimensions and on early palatoplasty outcomes in patients with Pierre Robin Sequence (PRS). In a prospective cohort study that enrolled 24 nonsyndromic patients with PRS, 12 submitted to the MDO group and 12 patients not treated (non-MDO group), the authors compared patients for cleft palate dimensions through 7 morphometric measurements at the moment of palatoplasty and for early palatoplasty outcomes. At palatoplasty, the MDO group presented a significant shorter distance between the posterior nasal spines (PNS-PNS, P < 0.001) and between uvular bases (UB-UB, P < 0.001), representing a reduction in cleft palate width. They also had significant soft palate lengthening represented by a larger distance between UB and retromolar space (UB-RM, P < 0.001) and UB and PNS (UB-PNS, P = 0.014). Their UB moved away from the posterior wall of the nasopharynx (UB-NPH, P < 0.001). The MDO group had a length of operative time significantly shorter (P < 0.001) and no early palatoplasty complications compared with the non-MDO group. In conclusion, MDO acted as an orthopedic procedure that reduced cleft palate width and elongated the soft palate in patients with PRS. These modifications enabled a reduction of around 11% in the length of operative time of palatoplasty (P < 0.001). PMID:27315309

  20. Distraction osteogenesis of free flap reconstructed mandible following ameloblastoma resection for optimal functional rehabilitation.

    PubMed

    Bousdras, V A; Kalavrezos, N

    2014-01-01

    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

  1. A new 2-dimensional method for constructing visualized treatment objectives for distraction osteogenesis of the short mandible.

    PubMed

    van Beek, H

    2010-01-01

    Open bite development during distraction of the mandible is common and partly due to inaccurate planning of the treatment. Conflicting guidelines exist in the literature. A method for Visualized Treatment Objective (VTO) construction is presented as an aid for determining the correct orientation of monodirectional and multidirectional distractors. Distraction on the left and on the right side of the mandible takes place in a parallel manner in order to maintain intercondylar width. It follows that in the absence of marked asymmetry, the amount of mandibular body distraction, the amount of ramus distraction and (should it apply), the amount of closure of the gonial angle, can be derived from a simple 2-dimensional plan. After presurgical orthodontic treatment, a cephalogram is taken and a VTO is constructed, that aims at a good occlusion with the enhanced mandible in centric relation, with little or no change of the original position of the rami. PMID:19837600

  2. Can the material properties of regenerate bone be predicted with non-invasive methods of assessment? Exploring the correlation between dual X-ray absorptiometry and compression testing to failure in an animal model of distraction osteogenesis.

    PubMed

    Monsell, Fergal; Hughes, Andrew William; Turner, James; Bellemore, Michael C; Bilston, Lynne

    2014-04-01

    Evaluation of the material properties of regenerate bone is of fundamental importance to a successful outcome following distraction osteogenesis using an external fixator. Plain radiographs are in widespread use for assessment of alignment and the distraction gap but are unable to detect bone formation in the early stages of distraction osteogenesis and do not quantify accurately the structural properties of the regenerate. Dual X-ray absorptiometry (DXA) is a widely available non-invasive imaging modality that, unlike X-ray, can be used to measure bone mineral content (BMC) and density quantitatively. In order to be useful as a clinical investigation; however, the structural two-dimensional geometry and density distributions assessed by DXA should reflect material properties such as modulus and also predict the structural mechanical properties of the regenerate bone formed. We explored the hypothesis that there is a relationship between DXA assessment of regenerate bone and structural mechanical properties in an animal model of distraction osteogenesis. Distraction osteogenesis was carried out on the tibial diaphysis of 41 male, 12 week old, New Zealand white rabbits as part of a larger study. Distraction started after a latent period of 24 h at a rate of 0.375 mm every 12 h and continued for 10-days, achieving average lengthening of 7.1 mm. Following an 18-day period of consolidation, the regenerate bone was subject to bone density measurements using a total body dual-energy X-ray densitometer. This produced measurement of BMC, bone mineral density (BMD) and volumetric bone mineral density (vBMD). The tibiae were then disarticulated and cleaned of soft tissue before loading in compression to failure using an Instron mechanical testing machine (Instron Corporation, Massachusetts USA). Using Spearman rank correlation and linear regression, there was a significant correlation between vBMD and the Modulus of Elasticity, Yield Stress and Failure Stress of the

  3. Patient discomfort and other side effects after bilateral sagittal split osteotomy or distraction osteogenesis of the mandible: a randomized clinical trial.

    PubMed

    Baas, E M; van Gemert, B P H M; Bierenbroodspot, F; Milstein, D M J; de Lange, J

    2015-09-01

    A randomized clinical trial was conducted to compare bilateral sagittal split osteotomy (BSSO) with distraction osteogenesis (DO) for the advancement of the mandible, with a focus on patient discomfort, postoperative pain, the need for analgesics, and occurrence of infection. All patients were non-syndromal, had a class II hypoplastic mandible, and had not undergone previous mandibular surgery. A total of 66 patients were allocated randomly to the BSSO group (32 patients) or the DO group (34 patients). Sixty-three patients were eligible for evaluation, 29 in the BSSO group and 34 in the DO group. Patients in the DO group experienced more pain after 6 days postoperative, and were administered more analgesics after 5 days postoperative than patients in the BSSO group (P=0.030 and P=0.045, respectively). The operating time was significantly shorter for the BSSO group than for the DO group (78 min vs. 100 min, P=0.024). All postoperative infections (12 in total) emerged in the DO group (P=0.005). All patients in the DO group had a second surgery in day care to remove the distractor, while two patients in the BSSO group needed plate removal. It is concluded that patients experienced more pain after DO, needed more analgesics postoperatively, and had more infections in comparison to the BSSO group. PMID:26099918

  4. Simultaneous and differential fronto-orbital and midface distraction osteogenesis for syndromic craniosynostosis using rigid external distractor II.

    PubMed

    Medra, Ahmed Mohamed; Marei, Ahmed Gaber; Shehata, Ehab Ali; McGurk, Mark; Habib, Ahmed

    2012-09-01

    In syndromic craniosynostosis, the relation between the supraorbital area and the frontal bone is not good, and it is not possible to reform this area with 1-block advancement. To avoid this problem, the frontal bone is separated from the fronto-orbital bandeau, each is reshaped and remodeled separately, and then both are reattached. The retrusion of the midface, especially in syndromic craniosynostosis, is usually greater than that of cranial bones, so the technique usually separating the midface from the cranium is Le Fort III osteotomy, which allows differential distraction of each part. In this procedure, the cranial and midfacial bones are advanced simultaneously and differentially, both to the planned extent, in a single-stage operation, using rigid external distractor II, correcting exorbitism, respiratory embarrassment, and cranial structures and avoiding eye complications in the future. This procedure was used, with a follow-up, in 10 patients with syndromic craniosynostosis from 2 to 5 years. PMID:22976628

  5. Role of parathyroid hormone therapy in reversing radiation-induced nonunion and normalization of radiomorphometrics in a murine mandibular model of distraction osteogenesis

    PubMed Central

    Gallagher, K. Kelly; Deshpande, Sagar; Tchanque-Fossuo, Catherine N.; Donneys, Alexis; Sarhaddi, Deniz; Nelson, Noah S.; Chepeha, Douglas B.; Buchman, Steven R.

    2014-01-01

    Background The use of mandibular distraction osteogenesis (MDO) for tissue replacement after oncologic resection or for defects caused by osteoradionecrosis has been described but, in fact, has seen limited clinical utility. Previous laboratory work has shown that radiation (XRT) causes decreased union formation, decreased cellularity, and decreased mineral density in an animal model of MDO. Our global hypothesis is that radiation-induced bone damage is partly driven by the pathologic depletion of both the number and function of osteogenic cells. Parathyroid hormone (PTH) is a U.S. Food and Drug Administration-approved anabolic hormonal therapy that has demonstrated efficacy for increasing bone mineral density for the treatment of osteoporosis. We postulate that intermittent systemic administration of PTH will serve as an anabolic stimulant to cellular function that will act to reverse radiation-induced damage and enhance bone regeneration in a murine mandibular model of DO. Methods A total of 20 isogenic male Lewis rats were randomly assigned into 3 groups. Group 1 (XRT-DO, n = 7) and group 2 (XRT-DO-PTH, n = 5) received a human bioequivalent dose of 70 Gy fractionated over 5 days. All groups including group 3 (DO, n = 8) underwent a left unilateral mandibular osteotomy with bilateral external fixator placement. Four days later, mandibular DO was performed at a rate of 0.3 mm every 12 hours to reach a maximum gap of 5.1 mm. Group 2 was injected PTH (60 μg/kg) subcutaneously daily for 3 weeks following the start of MDO. On postoperative day 41, all left hemimandibles were harvested. Micro-CT at 45-μm voxel size was performed and radiomorphometrics parameters of bone mineralization were generated. Union quality was evaluated on a 4-point qualitative grading scale. Radiomorphometric data were analyzed using 1-way ANOVA, and union quality assessment was analyzed via the Mann–Whitney test. Statistical significance was considered at p ≤ .05. Results Groups 1 and 2

  6. The marine sponge-derived inorganic polymers, biosilica and polyphosphate, as morphogenetically active matrices/scaffolds for the differentiation of human multipotent stromal cells: potential application in 3D printing and distraction osteogenesis.

    PubMed

    Wang, Xiaohong; Schröder, Heinz C; Grebenjuk, Vladislav; Diehl-Seifert, Bärbel; Mailänder, Volker; Steffen, Renate; Schloßmacher, Ute; Müller, Werner E G

    2014-02-01

    , supplemented with polyP and/or biosilica, is a suitable biomaterial that promotes the growth and differentiation of hMSCs and might be beneficial for application in 3D tissue printing of hMSCs and for the delivery of hMSCs in fractures, surgically created during distraction osteogenesis. PMID:24566262

  7. The Marine Sponge-Derived Inorganic Polymers, Biosilica and Polyphosphate, as Morphogenetically Active Matrices/Scaffolds for the Differentiation of Human Multipotent Stromal Cells: Potential Application in 3D Printing and Distraction Osteogenesis

    PubMed Central

    Wang, Xiaohong; Schröder, Heinz C.; Grebenjuk, Vladislav; Diehl-Seifert, Bärbel; Mailänder, Volker; Steffen, Renate; Schloßmacher, Ute; Müller, Werner E. G.

    2014-01-01

    , supplemented with polyP and/or biosilica, is a suitable biomaterial that promotes the growth and differentiation of hMSCs and might be beneficial for application in 3D tissue printing of hMSCs and for the delivery of hMSCs in fractures, surgically created during distraction osteogenesis. PMID:24566262

  8. Distracted Driving

    MedlinePlus

    ... combines all three types of distraction. 3 How big is the problem? Deaths In 2013, 3,154 ... European countries. More A CDC study analyzed 2011 data on distracted driving, including talking on a cell ...

  9. Osteogenesis imperfecta.

    PubMed

    Forlino, Antonella; Marini, Joan C

    2016-04-16

    Osteogenesis imperfecta is a phenotypically and molecularly heterogeneous group of inherited connective tissue disorders that share similar skeletal abnormalities causing bone fragility and deformity. Previously, the disorder was thought to be an autosomal dominant bone dysplasia caused by defects in type I collagen, but in the past 10 years discoveries of novel (mainly recessive) causative genes have lent support to a predominantly collagen-related pathophysiology and have contributed to an improved understanding of normal bone development. Defects in proteins with very different functions, ranging from structural to enzymatic and from intracellular transport to chaperones, have been described in patients with osteogenesis imperfecta. Knowledge of the specific molecular basis of each form of the disorder will advance clinical diagnosis and potentially stimulate targeted therapeutic approaches. In this Seminar, together with diagnosis, management, and treatment, we describe the defects causing osteogenesis imperfecta and their mechanism and interrelations, and classify them into five groups on the basis of the metabolic pathway compromised, specifically those related to collagen synthesis, structure, and processing; post-translational modification; folding and cross-linking; mineralisation; and osteoblast differentiation. PMID:26542481

  10. Distracted driving

    MedlinePlus

    ... stay safe with a cell phone in the car. ... for Disease Control and Prevention Injury Prevention & Control. Motor Vehicle Safety. www.cdc.gov/motorvehiclesafety/distracted_driving . Accessed May ...

  11. Distraction arthroplasty.

    PubMed

    Morse, Kenneth R; Flemister, A Samuel; Baumhauer, Judith F; DiGiovanni, Benedict F

    2007-03-01

    Few joint-preserving surgical options exist for the patient who has ankle arthritis refractory to conservative measures. Therefore, continuous effort is afforded to the development of additional treatment options for such patients. Distraction arthroplasty has been proposed as one of these options for the patient in whom fusion or joint replacement is not appropriate. Although the mechanism of action remains unknown, the reports of several researchers support the potential beneficial effects that can be obtained from joint distraction arthroplasty in the severely osteoarthritic ankle. Furthermore, the studies published to date suggest that these effects may not only persist for years but also improve as time progresses during the first several years after treatment. Although additional laboratory studies are needed to understand the biochemical and biomechanical effects of distraction, additional prospective clinical studies are also needed to further understand its efficacy and appropriate patient population. The data thus far suggests that joint distraction arthroplasty may be a viable alternative treatment to arthrodesis and replacement for the young patient who has a congruent, painful, mobile, arthritic ankle joint. PMID:17350509

  12. Deadly distractions.

    PubMed

    Zuzek, Crystal

    2013-04-01

    In 2011, the National Transportation Safety Board urged all states to ban the use of portable electronic devices while driving, including hand-held and hands-free devices. Texting while driving concerns several Texas legislators, who have filed bills, backed by the Texas Medical Association, to ban the practice. TMA physicians recognize that the use of hand-held and hands-free devices and other factors associated with distracted driving affect their patients' safety. PMID:23546834

  13. [Cytokines and osteogenesis].

    PubMed

    Fujiwara, Makoto; Ozono, Keiichi

    2014-06-01

    Many cytokines associate with proliferation, differentiation and activation of osteoblasts which have an important role in osteogenesis. TGF-β, BMP, IGF, FGF, Hedgehog, Notch, IL and WNT signaling pathways and their inhibitors have been revealed to correlate to osteogenesis, and those gene mutations have been shown to cause various bone disorders. It has been suggested that there are common pathways or crosstalk in these cytokine signaling each other, but mechanism of their complicated regulation on osteogenesis has been unclear. It was expected that the knowledge about these cytokines will apply to clinical therapies of bone diseases. PMID:24870835

  14. Vertical distraction of a free vascularized osteocutaneous scapular flap in the reconstructed mandible for implant therapy.

    PubMed

    Hirota, M; Mizuki, N; Iwai, T; Watanuki, K; Ozawa, T; Maegawa, J; Matsui, Y; Tohnai, I

    2008-05-01

    This paper describes a case of vertical distraction osteogenesis of a free vascularized osteocutaneous scapular flap in the reconstructed mandible before implant therapy. The patient was a 67-year-old woman with squamous cell carcinoma of the right lower gingiva. She underwent segmental mandibulectomy for tumor ablation and reconstruction with an osteocutaneous scapular flap. The distraction protocol, clinical course and implant therapy are presented. Through this procedure, the bone height of the scapular graft increased by 10mm. Implants with adequate length could be placed in the distracted area. Two years after masticatory loading, the condition of these implants was stable. Vertical distraction osteogenesis of the scapular flap was considered effective when performed before implant therapy, to facilitate postoperative functional and esthetic restoration after tumor resection. PMID:18367380

  15. Learning to Ignore Distracters

    PubMed Central

    Rozek, Ellen; Kemper, Susan; McDowd, Joan

    2011-01-01

    Eyetracking has indicated that older and young adults process distracters similarly when reading single sentences. The present study extended this approach by presenting short paragraphs sentence by sentence. Eyetracking measures included reading times per word, and the duration of the first fixation and total fixations to the distracters and target words. Comprehension was tested following each paragraph and recognition of distracters and target words was assessed. The results indicated that young adults were able to learn to ignore the distracters as they read through the paragraphs whereas older adults were less successful at learning to ignore the distracters. PMID:22004518

  16. Complex Compound Fracture of Tibia Managed with Distraction Osteogenesis

    PubMed Central

    Parekh, Hemant Prakash; Dwidmuthe, Samir Chandrakant; Patil, Sampat Dumbre; Sonar, Satish

    2014-01-01

    Introduction: The treatment of tibia bone loss can be challenging. The surgical options for the treatment of bone loss include bone transport, vascularized fibula graft, and induced membrane. Case Report: We present a case of complex compound fracture of tibia with bone loss. Interestingly patient sustained this injury in spite of having intramedullary nail in tibia which was inserted to stabilize previous fracture 9 months prior to trauma. The proximal half of the nail was protruding out of the wound at the time of presentation in emergency department. The nail was removed and stabilized with external fixator after wound closure. The bone gap and nonunion at fracture site was managed with Ilizarov fixator. At the end of treatment patient got satisfactory functional outcome. Conclusion: Ilizarov method is a biologic and comprehensive method for management of bone loss, non union and limb length discrepancy. PMID:27298985

  17. Internal calvarial bone distraction in rabbits with delayed-onset coronal suture synostosis.

    PubMed

    Losken, H W; Mooney, M P; Zoldos, J; Tschakaloff, A; Burrows, A M; Smith, T D; Cooper, G M; Kapucu, M R; Siegel, M I

    1998-09-01

    Recent studies have identified a subpopulation of craniosynostotic individuals who exhibit progressive or delayed-onset synostosis and mild craniofacial growth abnormalities. These individuals may be good candidates for nonextirpation, distraction osteogenesis therapy. The present study was designed to test this hypothesis by using internal calvarial bone distraction in a rabbit model with familial delayed-onset craniosynostosis. Data were collected from 159 rabbits: 71 normal controls, 72 with delayed-onset coronal suture synostosis, 8 with delayed-onset coronal suture synostosis and coronal suturectomy, and 8 with delayed-onset coronal suture synostosis and distraction. At 10 days of age, all rabbits had amalgam markers placed on both sides of the frontonasal, coronal, and anterior lambdoidal sutures. At 25 days of age, correction was accomplished through either a 5-mm-wide suturectomy or distraction osteogenesis. An internal distraction appliance was fixed to the frontal and parietal bones and percutaneously and intermittently activated at an average of 0.10 mm/day for 42 days (4.11 mm total). Serial radiographs were taken at 10, 25, 42, and 84 days of age. Results revealed that rabbits with delayed-onset synostosis had significantly (p < 0.01) reduced coronal suture growth rates (0.04 mm/day) compared with the other three groups (0.07 mm/day). Rabbits with suturectomy and rabbits with distraction showed similar coronal suture responses. However, from 42 to 84 days of age, rabbits with distraction showed reduced growth at the vault sutures and abnormal growth patterns in cranial vault width, cranial vault shape, and cranial base angulation compared with the other three groups. Results demonstrated that, although the normal coronal suture growth rate was maintained in rabbits with delayed-onset synostosis using intermittent distraction osteogenesis, normal adult craniofacial structure was not achieved. Such anomalous growth was probably a result of altered growth

  18. Unilateral Le Fort I Osteotomy for Rehabilitating the Large Alveolar Cleft and Vertical Malocclusion With the Distraction Technique.

    PubMed

    Baykul, Timuçin; Aydin, Mustafa Asim; Findik, Yavuz; Esenlik, Elçin

    2016-05-01

    Rehabilitation of the large alveolar clefts with autogenous graft or distraction osteogenesis is one of the most common treatment choices. Depending on the clinical situation such as vertical deficiencies, linear transport of the segment does not always ensure a proper closure of the cleft space. In this report, the authors present a patient in whom large unilateral cleft and vertical alveolar deficiency were closed by unilateral Le Fort I osteotomy and distraction technique using the orthodontic elastics. PMID:27054420

  19. Biomimetic Scaffolds for Osteogenesis

    PubMed Central

    Yuan, Nance; Rezzadeh, Kameron S.; Lee, Justine C.

    2015-01-01

    Skeletal regenerative medicine emerged as a field of investigation to address large osseous deficiencies secondary to congenital, traumatic, and post-oncologic conditions. Although autologous bone grafts have been the gold standard for reconstruction of skeletal defects, donor site morbidity remains a significant limitation. To address these limitations, contemporary bone tissue engineering research aims to target delivery of osteogenic cells and growth factors in a defined three dimensional space using scaffolding material. Using bone as a template, biomimetic strategies in scaffold engineering unite organic and inorganic components in an optimal configuration to both support osteoinduction as well as osteoconduction. This article reviews the various structural and functional considerations behind the development of effective biomimetic scaffolds for osteogenesis and highlights strategies for enhancing osteogenesis. PMID:26413557

  20. Model of the distraction callus tissue behavior during bone transport based in experiments in vivo.

    PubMed

    Mora-Macías, Juan; Reina-Romo, Esther; Domínguez, Jaime

    2016-08-01

    Bone transport studies have measured the forces related to bone segment distraction (Brunner et al., 1994; Hyodo et al., 1996). However, no distraction force distribution between callus and docking-site was reported. Besides, most of these works have not provided continuous and long-term force relaxation measurements. The fit of the relaxation curves allows for modeling the mechanical behavior of the callus tissue during distraction osteogenesis, particularly in bone transport, where the resistance of the soft tissue and muscle is reduced compared with the bone lengthening. Bone transport experiments were carried out in sheep in which the distraction force was monitored continuously in vivo. The daily force relaxation curves were fitted, and two experimental models of the mechanical behavior of the callus tissue were obtained, assuming the total daily force relaxation or the accumulation of the residual forces. According to these models, the residual force 24h after each distraction step was a maximum of 71.6N, and the peak distraction force increased with the number of steps from 7-34N to 41-246N. The maximum residual force values that were predicted are much lower than those measured during bone lengthening in the literature. These results indirectly differentiate the influence of the surrounding soft tissues during bone transport compared with bone lengthening. Moreover, experimental measurements showed that distraction force through the docking-site was negligible with respect to distraction force through the callus. Experimental models of the callus tissue allow for an understanding of the mechanobiology of distraction osteogenesis and for predicting outcomes in its application processes. PMID:27111628

  1. [Maxillary sinus hypoplasia].

    PubMed

    Plaza, G; Ferrando, J; Martel, J; Toledano, A; de los Santos, G

    2001-03-01

    Maxillary sinus hypoplasia is rare, with an estimated prevalence of 1-5%. Out of the CT scans performed in sinusal patients between March 1998 and June 1999, we report on 4 isolated maxillary sinus hypoplasia, 4 maxillary sinus hypoplasia associated to concha bullosa, and 10 isolated conchae bullosas. All cases were evaluated by nasosinusal endoscopy and CT scan. Size, location and uni/bilateral presentation of concha bullosa is correlated to maxillary sinus hypoplasia presence, specially with regards to uncinate process presence, medial or lateral retraction. The pathogenesis of maxillary sinus hypoplasia is reviewed, and its relation to concha bullosa, evaluating how this could explain some cases of the so called chronic maxillary sinus atelectasia, as an acquired and progressive variant of maxillary sinus hypoplasia in adults. PMID:11428268

  2. Distractions in Everyday Driving

    MedlinePlus

    ... 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 ...

  3. Evaluation of cranial bone transport distraction with and without adipose grafting.

    PubMed

    Koch, Felix P; Yuhasz, Mikell M; Travieso, Rob; Wong, Kenneth; Clune, James; Zhuang, Zhen W; Van Houten, Joshua; Steinbacher, Derek M

    2014-05-01

    Transport distraction osteogenesis (DO) can be used to autologously reconstitute calvarial defects. The purpose of this study is to histomorphologically interrogate osteogenic formation during cranial transport distraction using a novel device. We also evaluate the effect of fat grafting on the regenerate and soft-tissue stability during distraction. This study was approved by Yale IACUC. Ten male New Zealand white rabbits (3 mo; 3.5 kg) were used (8 treatment, 2 control). A 16 × 16 mm defect was created abutted by a 10 × 16 mm transport disc. The device was fixated anterioposteriorly. Four animals were fat-grafted using 2 mL of subdermal intrascapular fat deposited along the distraction site. Latency (1 d), active distraction (12-14 d) (1.5 mm/d), and consolidation (4 wk) followed. Calcein and xylene orange fluorochromes were injected subcutaneously during and post-distraction to mark sites of bone formation. Following sacrifice, osteogenesis was assessed using microCT, histology, and fluorescence. Treatment animals demonstrated regenerate bone between distracted segments on microCT. MicroCT analysis of non-fat-grafted and fat-grafted animals revealed a mean density of 2271.95 mgHA/ccm and 2254.27 mgHA/ccm (P = 0.967), respectively, and defect bone versus total volume (BV/TV) of 0.0999 and 0.0766 (P = 0.5979), respectively. Controls had minimal reossification. Histologically, mean densities measured 43.63% and 8.19%, respectively. Fluorescence revealed ossification from the callus as well as from dura and periosteum in the cranial defect. Transport distraction is effective to reconstruct critically sized rabbit calvarial defects. Regenerate bone arises predominantly from the callus with contribution from surrounding dura and periosteum. Adipose grafting is well tolerated but does not enhance osseous regeneration. PMID:24820707

  4. Electronic gaming as pain distraction.

    PubMed

    Jameson, Eleanor; Trevena, Judy; Swain, Nic

    2011-01-01

    The current study investigated whether active distraction reduces participants' experience of pain more than passive distraction during a cold pressor task. In the first experiment, 60 participants were asked to submerge their hand in cold (2°C) water for as long as they could tolerate. They did this with no distraction, and then with active (electronic gaming system) and passive (television) distraction, in randomly assigned order. Tolerance time, pain intensity ratings and task absorption ratings were measured for each condition. A second experiment attempted to control for participants' expectations about the effects of distraction on pain. Forty participants underwent the same experimental procedure, but were given verbal suggestions about the effects of distraction by the experimenter before each distraction condition. Participants in both experiments had a significantly higher pain tolerance and reported less pain with the active distraction compared with passive or no distraction. Participants reported being more absorbed, and were significantly more willing to do the task again when they had the active distraction compared with both passive distraction and no distraction. They also had more enjoyment, less anxiety and greater reduction in pain with active distraction than with passive distraction. There was no effect of suggestion. These experiments offer further support for the use of electronic games as a method of pain control. PMID:21369538

  5. Pre-arthroplastic and simultaneous mandibular distraction for correction of facial deformity in temporomandibular joint ankylosis

    PubMed Central

    Chellappa, A.L.; Mehrotra, D.; Vishwakarma, K.; Mahajan, N.; Bhutia, D.P.

    2015-01-01

    Introduction In cases of temporomandibular joint (TMJ) ankylosis, interposition arthroplasty allows return of functional jaw movements. In order to improve the facial appearance, distraction osteogenesis is the treatment of choice, and may be timed either as a pre-arthroplastic, simultaneous or post-arthroplastic procedure. This study was planned to compare the treatment outcomes of pre-arthroplastic distraction (PAD) and simultaneous arthroplastic distraction (SAD) to establish the better treatment modality in terms of improvement in function and aesthetics. Materials and methods This prospective randomized experimental study included 20 children and adolescents suffering from facial deformity due to long standing unilateral TMJ ankylosis. They were randomly allocated to the two surgical groups with ten in each group. Result Both groups resulted in good facial symmetry and aesthetics. Initially, during the distraction period, mouth opening of SAD group scored less than that of PAD group but became comparable in 30 days. More pain at the distraction site and over the normal TMJ was observed in PAD group. The excursive movements were almost comparable in both the groups. Conclusion We conclude that both procedures are effective in correcting the post-ankylotic deformity and improving function. Although PAD has better control over movement of the distracting segment, the contralateral TMJ may experience pain. SAD requires a shorter management period but is associated with a temporary decrease in function. Also, control of distraction may be difficult and chances of reankylosis are always there. PMID:26587380

  6. Comparing calvarial transport distraction with and without radiation and fat grafting.

    PubMed

    Yuhasz, Mikell M; Koch, Felix P; Kwiatkowski, Anna; Young, Calvin; Clune, James; Travieso, Rob; Wong, Kenneth; Van Houten, Joshua; Steinbacher, Derek M

    2014-10-01

    The purpose of this study is to: a) assess transport distraction to reconstruct cranial defects in radiated and non-radiated fields b) examine adipose grafting's effect on the bony regenerate and overlying wound, and c) elucidate sources of bone formation during transport distraction osteogenesis. Twenty-three male New Zealand white rabbits (3 months; 3.5 kg) were used, 10 non-irradiated and 13 irradiated (17 treatment, 6 control) with a one-time fraction of 35 Gy. A 16 × 16 mm defect was abutted by a 10 × 16 mm transport disc 5 weeks after irradiation, and 11 animals were fat grafted at the distraction site. Latency (1 day), distraction (1.5 mm/day), and consolidation (4 weeks) followed. Fluorochromes were injected subcutaneously and microCT, fluorescence, and histology assessed. In distracted animals without fat grafting, bone density measured 701.87 mgHA/ccm and 2271.95 mgHA/ccm in irradiated and non-irradiated animals. In distracted animals with fat grafting, bone density measured 703.23 mgHA/ccm and 2254.27 mgHA/ccm in irradiated and non-irradiated animals. Fluorescence revealed ossification emanating from the dura, periosteum, and transport segment with decreased formation in irradiated animals. Transport distraction is possible for cranial reconstruction in irradiated fields but short-term osseous fill is significantly diminished. Adipose grafting enhances wound healing in previously irradiated fields but does not enhance ossification. PMID:24864072

  7. Pharmacological management of osteogenesis

    PubMed Central

    Nardone, Valeria; D'Asta, Federica; Brandi, Maria Luisa

    2014-01-01

    Osteogenesis and bone remodeling are complex biological processes that are essential for the formation of new bone tissue and its correct functioning. When the balance between bone resorption and formation is disrupted, bone diseases and disorders such as Paget's disease, fibrous dysplasia, osteoporosis and fragility fractures may result. Recent advances in bone cell biology have revealed new specific targets for the treatment of bone loss that are based on the inhibition of bone resorption by osteoclasts or the stimulation of bone formation by osteoblasts. Bisphosphonates, antiresorptive agents that reduce bone resorption, are usually recommended as first-line therapy in women with postmenopausal osteoporosis. Numerous studies have shown that bisphosphonates are able to significantly reduce the risk of femoral and vertebral fractures. Other antiresorptive agents indicated for the treatment of osteoporosis include selective estrogen receptor modulators, such as raloxifene. Denosumab, a human monoclonal antibody, is another antiresorptive agent that has been approved in Europe and the USA. This agent blocks the RANK/RANKL/OPG system, which is responsible for osteoclastic activation, thus reducing bone resorption. Other approved agents include bone anabolic agents, such as teriparatide, a recombinant parathyroid hormone that improves bone microarchitecture and strength, and strontium ranelate, considered to be a dual-action drug that acts by both osteoclastic inhibition and osteoblastic stimulation. Currently, anti-catabolic drugs that act through the Wnt-β catenin signaling pathway, serving as Dickkopf-related protein 1 inhibitors and sclerostin antagonists, are also in development. This concise review provides an overview of the drugs most commonly used for the control of osteogenesis in bone diseases. PMID:24964310

  8. What causes auditory distraction?

    PubMed

    Macken, William J; Phelps, Fiona G; Jones, Dylan M

    2009-02-01

    The role of separating task-relevant from task-irrelevant aspects of the environment is typically assigned to the executive functioning of working memory. However, pervasive aspects of auditory distraction have been shown to be unrelated to working memory capacity in a range of studies of individual differences. We measured individual differences in global pattern matching and deliberate recoding of auditory sequences, and showed that, although deliberate processing was related to short-term memory performance, it did not predict the extent to which that performance was disrupted by task-irrelevant sound. Individual differences in global sequence processing were, however, positively related to the degree to which auditory distraction occurred. We argue that much auditory distraction, rather than being a negative function of working memory capacity, is in fact a positive function of the acuity of obligatory auditory processing. PMID:19145024

  9. Osteogenesis imperfecta: cesarean deliveries in identical twins.

    PubMed

    Dinges, E; Ortner, C; Bollag, L; Davies, J; Landau, R

    2015-02-01

    Osteogenesis imperfecta is a congenital disorder resulting in multiple fractures and extremely short stature, usually necessitating cesarean delivery. Identical twins with severe osteogenesis imperfecta each of whom underwent a cesarean delivery with different anesthetic modalities are presented. A review of the literature and anesthetic options for cesarean delivery and postoperative analgesia for women with osteogenesis imperfecta are discussed. PMID:25433579

  10. Laser effects on osteogenesis

    NASA Astrophysics Data System (ADS)

    Freitas, I. G. F.; Baranauskas, V.; Cruz-Höfling, M. A.

    2000-02-01

    The traumatic or surgical cutting of a long bone is immediately followed by a sequence of repair processes in which the osteogenic cells of the periosteum start to proliferate and differentiate in osteoblast cells. In this work, we explored the influence of a He-Ne laser on osteogenesis after a controlled surgical fracture. We used young male adult Wistar rats (of mass between 250 and 300 g). The fracture was provoked by piercing a 2-mm-diameter hole in just one cortical tibia surface. Laser treatment was started 24 h after the surgery. The animals were separated into three groups, for different radiation doses, and after daily applications, they were sacrificed at 8 or 15 days. Light and electron microscopies revealed that the laser treatment of the lesion with doses of 31.5 and 94.7 J cm -2 resulted in the formation of thicker bony trabeculae, which indicates a greater synthesis of collagen fibers and therefore that the osteoblastic activity was increased by the low-energy laser radiation.

  11. Intranuclear Actin Regulates Osteogenesis

    PubMed Central

    Sen, Buer; Xie, Zhihui; Uzer, Gunes; Thompson, William R.; Styner, Maya; Wu, Xin; Rubin, Janet

    2016-01-01

    Depolymerization of the actin cytoskeleton induces nuclear trafficking of regulatory proteins and global effects on gene transcription. We here show that in mesenchymal stem cells (MSCs), cytochalasin D treatment causes rapid cofilin-/importin-9-dependent transfer of G-actin into the nucleus. The continued presence of intranuclear actin, which forms rod-like structures that stain with phalloidin, is associated with induction of robust expression of the osteogenic genes osterix and osteocalcin in a Runx2-dependent manner, and leads to acquisition of osteogenic phenotype. Adipogenic differentiation also occurs, but to a lesser degree. Intranuclear actin leads to nuclear export of Yes-associated protein (YAP); maintenance of nuclear YAP inhibits Runx2 initiation of osteogenesis. Injection of cytochalasin into the tibial marrow space of live mice results in abundant bone formation within the space of 1 week. In sum, increased intranuclear actin forces MSC into osteogenic lineage through controlling Runx2 activity; this process may be useful for clinical objectives of forming bone. PMID:26140478

  12. A piezoelectric motor-based microactuator-generated distractor for continuous jaw bone distraction.

    PubMed

    Park, Jong-Tae; Lee, Jae-Gi; Kim, Soo-Yeon; Kim, Gyu-Hag; Hu, Kyung-Seok; Cha, Jung-Yul; Kim, Hyung Jun; Kim, Hee-Jin

    2011-07-01

    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. PMID:21778842

  13. Effect of Dietary Ascorbic Acid on Osteogenesis of Expanding Midpalatal Suture in Rats

    PubMed Central

    Farhadian, Nasrin; Miresmaeili, Amirfarhang; Azar, Ramin; Zargaran, Massoumeh; Moghimbeigi, Abbas; Soheilifar, Sanaz

    2015-01-01

    Objectives: After maxillary expansion, a long period of retention is necessary to prevent early relapse. Therefore, it is beneficial to accelerate bone formation in the expanding midpalatal suture to reduce relapse. This study was designed to evaluate the effect of dietary vitamin C on osteogenesis of rat midpalatal suture during expansion. Materials and Methods: Fifty-four male Wistar rats were randomly divided into three groups, each with a control and an experimental subgroup. An open-loop spring was bonded to maxillary incisors of each animal to expand the premaxillary suture. Experimental groups received dietary vitamin C in their water. The rats in the three groups were sacrificed at three, nine or 17-day intervals after bonding the spring. Then, the premaxilla was dissected and sections were made and stained with hematoxylin and eosin and osteopontin marker. Osteoblasts and osteoclasts were counted in the suture. Two-way ANOVA and the Mann-Whitney-U test were used for analyzing the data. Results: After three days, the number of osteoblasts was significantly higher in the vitamin C group but after nine days it was significantly higher in the control group and after seventeen days there were no significant differences between the groups. Osteoclast counts were not significantly different between vitamin C and control groups. Conclusion: Vitamin C had a positive effect on osteogenesis at the beginning of bone formation in the expanding suture, but after nine days it had a negative effect on suture osteogenesis in rats. PMID:26005453

  14. Distracted Biking: An Observational Study.

    PubMed

    Wolfe, Elizabeth Suzanne; Arabian, Sandra Strack; Breeze, Janis L; Salzler, Matthew J

    2016-01-01

    Commuting via bicycle is a very popular mode of transportation in the Northeastern United States. 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 4 high traffic intersections in Boston during various peak commuting hours for 2 types of distractions: auditory (earbuds/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 = .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 and 15:00). Distracted bicycling is a prevalent safety concern in the city of Boston, as almost a 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

  15. Dental implants placed on bone subjected to vertical alveolar distraction show the same performance as those placed on primitive bone

    PubMed Central

    León-Camacho, María A.; Somoza-Martín, José M.; Fernández-González, Beatriz; Blanes-Vázquez-Gundín, Silvia; Gándara-Rey, José M.; García-García, Abel

    2013-01-01

    Introduction: Vertical osteogenic alveolar distraction (VOAD) allows for the augmentation of the alveolar ridge for the placement of dental implants in atrophic alveolar ridges. The goal of this paper is to assess long-term peri-implant bone resorption in implants placed on bones subjected to VOAD, comparing it with a group of patients who had implants placed directly on the alveolar bone without previous bone regeneration. Material and Methods: We conducted a follow-up study on 32 patients who were divided into two groups: The Distraction Group (14 patients), and the Distraction-Free Group (18 patients), who received a total of 100 implants. Peri-implant bone loss was measured by means of panoramic X-rays, at the time of loading and one year later, and in 35 implants of each group after 3 years of functional loading. Results: The peri-implant bone resorption (PBR) average observed in the Distraction Group at the time of prosthetic placement is higher (0.50±0.09 mm) than in the Distraction-Free Group (0.25±0.06 mm), showing statistically significant results (p=0.047). PBR levels 1 year after loading were the same for both groups (0.66 mm). At 3 years, they were higher in the Distraction Group (1.03 ± 0.22 mm vs. 0.68 ± 0.08 mm). Key words:Bone resorption, alveolar distraction osteogenesis, dental implants. PMID:23524476

  16. Hemangioma of the maxillary sinus.

    PubMed

    Most, D S

    1985-11-01

    Hemangiomas of the maxillary sinus are rare. Hemangiomas of the maxillary sinus with an associated phlebolith have not been previously reported. Severe bleeding can occur upon surgical removal of hemangiomas. PMID:3864111

  17. Distraction subtalar arthrodesis.

    PubMed

    Jackson, J Benjamin; Jacobson, Lance; Banerjee, Rahul; Nickisch, Florian

    2015-06-01

    There is a high potential for disability following calcaneal fracture. This potential exists whether a patient is treated with conservative or operative management. Subfibular impingement and irritation of the peroneal tendon and sural nerve may also be present. Posttraumatic arthritis of the subtalar joint can occur. In patients with symptomatic calcaneal malunion, systematic evaluation is required to determine the source of pain. Nonsurgical treatment may be effective. One surgical treatment option is subtalar distraction arthrodesis. High rates of successful arthrodesis and patient satisfaction have been reported with this surgical option in correctly selected patients. PMID:26043248

  18. Neural Basis of Visual Distraction

    ERIC Educational Resources Information Center

    Kim, So-Yeon; Hopfinger, Joseph B.

    2010-01-01

    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…

  19. Assessment of Mandibular Distraction Regenerate Using Ultrasonography and Cone Beam Computed Tomography: A Clinical Study.

    PubMed

    Dabas, Jitender; Mohanty, Sujata; Chaudhary, Zainab; Rani, Amita

    2016-03-01

    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

  20. [Front Block distraction].

    PubMed

    Esnault, Olivier

    2015-03-01

    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. PMID:25888045

  1. The distracted driver.

    PubMed

    Peters, G A; Peters, B J

    2001-03-01

    A serious health problem is developing from automobile collisions caused by distracted drivers. This is a result of the rapid proliferation of portable cellular telephones and personal organisers used while driving, the development of more sophisticated entertainment systems and instrument panel controls, the advent of navigation and television displays in vehicles and promises of sophisticated wireless e-mail, FAX and Internet services in the vehicle. Preoccupation with electronic gadgets may also degrade human driving performance. Many drivers however, sincerely believe they have the talent to do several things at the same time, such as hold and look at a cellular telephone in one hand and drive with a beverage container in the other hand whilst at the same time, exercise their personal skills. Obviously, they believe that they do not need two hands on the steering wheel and two eyes on the road. This is a unique situation requiring intensive health promotion as distracted or 'offensive driving' may be habit forming and difficult to change, any significant design remedies will be slow to arrive and may be circumvented, and the regulatory laws have proved difficult or impossible to enforce. This special need may require research to determine the most effective techniques for health promotion. PMID:11329694

  2. Corticotomy and compression osteogenesis in the posterior maxilla for treating severe anterior open bite.

    PubMed

    Kanno, T; Mitsugi, M; Furuki, Y; Kozato, S; Ayasaka, N; Mori, H

    2007-04-01

    A new technique is described for outpatient treatment of anterior open bite. The compression osteogenesis method with a two-stage corticotomy was used in the posterior maxilla to treat a woman with severe anterior open bite. Three-week post-surgical compression using anchor plates and elastics repositioned the posterior maxillary bone/teeth segments by 7 mm to the ideal superior position. The patient had a stable skeletal position of the maxilla at 14-month follow-up with satisfactory results and no complications after orthodontic treatment. This technique appears to be an efficient option for treating patients with anterior open bite. PMID:17110086

  3. Chronic odontogenic maxillary sinusitis.

    PubMed

    Ugincius, Paulius; Kubilius, Ricardas; Gervickas, Albinas; Vaitkus, Saulius

    2006-01-01

    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. PMID:16861848

  4. Reconstruction of large tibial bone defects following osteosarcoma resection using bone transport distraction: A report of two cases

    PubMed Central

    Yang, Zhengming; Jin, Libin; Tao, Huimin; Yang, Disheng

    2016-01-01

    The clinical efficiency of bone transport distraction osteogenesis in the reconstruction of large tibial defects following resection of osteosarcoma remains unclear. The current study presents two cases of large tibial defects treated with bone transport distraction using an Orthofix external fixator. Case 1 was a 29-year-old man with a tibial defect 11 cm in length, while case 2 was a 16-year-old girl with a 15-cm-long defect. Bone transport distraction osteogenesis was initiated for the both cases on day 14 following resection of the tibial osteosarcoma. Bone transport distraction in case 1 and 2 was continued for 16 and 28 months, respectively, and the patients were followed up for 51 and 56 months, respectively. The two patients did not exhibit any signs of tumor recurrence or tumor metastasis during the follow-up period. The Musculoskeletal Tumor Society functional scores at final follow-up visits were 22 and 18 for case 1 and 2, respectively. Based on the experience gained in these 2 cases, a bone transport is a viable option for the reconstruction of large tibial defects following osteosarcoma resection.

  5. Distracted Driving Raises Crash Risk

    MedlinePlus

    ... Raises Crash Risk Video technology and in-vehicle sensors showed that distracted driving, especially among new drivers, ... whenever the cars were moving. A suite of sensors recorded acceleration, sudden braking or swerving, and other ...

  6. Context effects on auditory distraction

    PubMed Central

    Chen, Sufen; Sussman, Elyse S.

    2014-01-01

    The purpose of the study was to test the hypothesis that sound context modulates the magnitude of auditory distraction, indexed by behavioral and electrophysiological measures. Participants were asked to identify tone duration, while irrelevant changes occurred in tone frequency, tone intensity, and harmonic structure. Frequency deviants were randomly intermixed with standards (Uni-Condition), with intensity deviants (Bi-Condition), and with both intensity and complex deviants (Tri-Condition). Only in the Tri-Condition did the auditory distraction effect reflect the magnitude difference among the frequency and intensity deviants. The mixture of the different types of deviants in the Tri-Condition modulated the perceived level of distraction, demonstrating that the sound context can modulate the effect of deviance level on processing irrelevant acoustic changes in the environment. These findings thus indicate that perceptual contrast plays a role in change detection processes that leads to auditory distraction. PMID:23886958

  7. Leading to distraction: Driver distraction, lead car, and road environment.

    PubMed

    Kountouriotis, G K; Merat, N

    2016-04-01

    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. PMID:26785327

  8. The epidemic of distraction.

    PubMed

    Weksler, Marc E; Weksler, Babette B

    2012-01-01

    Multitasking is a rapidly growing phenomenon affecting all segments of the population but is rarely as successful as its proponents believe. The use of mobile electronic devices contributes importantly to multitasking and cognitive overload. Although personal electronic devices provide many benefits, their adverse effects are frequently overlooked. Personal observation and a review of the scientific literature supports the view that overuse or misuse of personal electronic devices promotes cognitive overload, impairs multitasking and lowers performance at all ages but particularly in the elderly. This phenomenon appears to be rapidly increasing and threatens to become a tsunami as spreading electronic waves cause an 'epidemic of distraction'. Mobile electronic devices often bring benefits to their users in terms of rapid access to information. However, there is a dark side to the increasing addiction to these devices that challenges the health and well-being of the entire population, targeting, in particular, the aged and infirm. New approaches to information gathering can foster creativity if cognitive overload is avoided. PMID:22572729

  9. Maxillary sinus carcinoma

    SciTech Connect

    Lee, F.; Ogura, J.H.

    1981-01-01

    Primary site control, anatomical site of failure, survival, and complications of treatment were determined in a retrospective review of primary maxillary sinus carcinoma. Sixty-one patients were treated by radiation followed by surgery and 35 by radiation alone. Primary tumor control was achieved in 69% of patients receiving combined treatment, 14% of patients treated with radiation alone, and 49% of all patients. Local control did not differ with histological type. Virtually all epidermoid and undifferentiated carcinoma recurrences occurred within 2 years, but 27% of adenocarcinomas recurred after 2 years.

  10. Intramedullary rodding in osteogenesis imperfecta.

    PubMed

    Mulpuri, K; Joseph, B

    2000-01-01

    The results of intramedullary rodding of long bones of 16 children with osteogenesis imperfecta, over a 10-year period, were analyzed. Sheffield elongating rods or non-elongating rods were used. The frequency of fractures was dramatically reduced after implantation of either type of rod, and the ambulatory status improved in all instances. The results were significantly better after Sheffield rodding with regard to the frequency of complications requiring reoperations and the longevity of the rods. Migration of the rods, encountered frequently, appears to be related to improper placement of the rods in the bone. It seems likely that if care is taken to ensure precise placement of a rod of appropriate size, several of these complications may be avoided. PMID:10739296

  11. Mucopyocele of the maxillary sinus.

    PubMed

    Kshar, Avinash; Patil, Abhijeet; Umarji, Hemant; Kadam, Sonali

    2014-01-01

    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

  12. Mucopyocele of the maxillary sinus

    PubMed Central

    Kshar, Avinash; Patil, Abhijeet; Umarji, Hemant; Kadam, Sonali

    2014-01-01

    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

  13. New Perspectives on Osteogenesis Imperfecta

    PubMed Central

    Forlino, Antonella; Cabral, Wayne A.; Barnes, Aileen M.; Marini, Joan C.

    2012-01-01

    A new paradigm has emerged for osteogenesis imperfecta (OI) as a collagen-related disorder. The more prevalent autosomal dominant forms of OI are caused by primary defects in type I collagen, while autosomal recessive forms are caused by deficiency of proteins which interact with type I procollagen for post-translational modification and/or folding. Factors contributing to the mechanism of dominant OI include intracellular stress, disruption of interactions between collagen and non-collagenous proteins, compromised matrix structure, abnormal cell-cell and cell-matrix interactions and tissue mineralization. Recessive OI is caused by deficiency of any of the three components of the collagen prolyl 3-hydroxylation complex; absence of 3-hydroxylation is associated with increased modification of the collagen helix, supporting delayed collagen folding. Other causes of recessive OI include deficiency of collagen chaperones, FKBP65 or HSP47. Murine models are crucial to uncovering the common pathways in dominant and recessive OI bone dysplasia. Clinical management of OI is multidiscipinary, encompassing substantial progress in physical rehabilitation and surgical procedures, managment of hearing, dental and pulmonary abnormalities, as well as drugs such as bisphosphonates and rGH. Novel treatments using cell therapy or new drug regimens hold promise for the future. PMID:21670757

  14. How Concentration Shields Against Distraction

    PubMed Central

    Marsh, John E.

    2015-01-01

    In this article, we outline our view of how concentration shields against distraction. We argue that higher levels of concentration make people less susceptible to distraction for two reasons. One reason is that the undesired processing of the background environment is reduced. For example, when people play a difficult video game, as opposed to an easy game, they are less likely to notice what people in the background are saying. The other reason is that the locus of attention becomes more steadfast. For example, when people are watching an entertaining episode of their favorite television series, as opposed to a less absorbing show, attention is less likely to be diverted away from the screen by a ringing telephone. The theoretical underpinnings of this perspective, and potential implications for applied settings, are addressed. PMID:26300594

  15. Chronic ethanol exposure inhibits distraction osteogenesis in a mouse model: role of the TNF signaling axis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tumor necrosis factor-alpha (TNF-alpha) is an inflammatory cytokine that modulates osteoblastogenesis. In addition, the demonstrated inhibitory effects of chronic ethanol exposure on direct bone formation in rats are hypothetically mediated by TNF-alpha signaling. The effects in mice are unreported....

  16. Callus massage after distraction osteogenesis using the concept of lengthening then dynamic plating.

    PubMed

    Grünwald, Leonard; Döbele, Stephan; Höntzsch, Dankward; Slongo, Theddy; Stöckle, Ulrich; Freude, Thomas; Schröter, Steffen

    2015-08-01

    Correction of complex deformities is a challenging procedure. Long-term wearing of a fixator after correction and lengthening are inconvenient and has a high rate of complication. The goals of the surgical treatment in the presented case were: (1) correction of the deformity and lengthening of the left leg by the Taylor spatial frame (TSF, Smith and Nephew, Marl, Germany); (2) reduction in the time the patient wears the TSF by changing the fixation system to a plate (lengthening then plating-LTP) and using a locking compression plate in conjunction with the 5.0 dynamic locking screws in order to accelerate bone healing. PMID:26338093

  17. Distracted by Your Mind? Individual Differences in Distractibility Predict Mind Wandering

    ERIC Educational Resources Information Center

    Forster, Sophie; Lavie, Nilli

    2014-01-01

    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…

  18. Predicting Visual Distraction Using Driving Performance Data

    PubMed Central

    Kircher, Katja; Ahlstrom, Christer

    2010-01-01

    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

  19. Suspect osteogenesis imperfecta in a male kitten.

    PubMed

    Evason, Michelle D; Taylor, Susan M; Bebchuk, Trevor N

    2007-03-01

    A 4.5-month-old, male domestic shorthair was presented with bilateral femoral fractures after falling from a low height. Radiographs revealed reduced radio-opacity and thin cortices of all long bones. A presumptive diagnosis of osteodystrophy, secondary to osteogenesis imperfecta, was made on postmortem examination. PMID:17436908

  20. 77 FR 61048 - Distracted Driving Grant Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-05

    ... grant program, 77 FR 51610 (Aug. 24, 2012), which established an application deadline of October 9, 2012... 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...

  1. Distractions in the School Science Laboratory

    ERIC Educational Resources Information Center

    Hamza, Karim M.

    2013-01-01

    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…

  2. Pediatric maxillary and mandibular tumors.

    PubMed

    Trosman, Samuel J; Krakovitz, Paul R

    2015-02-01

    Pediatric maxillary and mandibular tumors offer considerable challenges to otolaryngologists, oral surgeons, pathologists, and radiologists alike. Because of the close proximity to vital structures, appropriate steps toward a definitive diagnosis and treatment plan are of paramount importance. This article reviews the most common causes of pediatric jaw masses and discusses diagnostic and therapeutic considerations and recommendations. PMID:25442129

  3. Distractions in the School Science Laboratory

    NASA Astrophysics Data System (ADS)

    Hamza, Karim M.

    2013-08-01

    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 examined in close detail the conversations of three groups of high school students trying to explain how a real galvanic cell works. The three groups experienced the same two distractions, (1) a nonworking light-emitting diode and (2) negative readings on a voltmeter. The analysis reveals how one of the groups, through a series of contingencies, successively made the two distractions continuous with the main purpose of the activity. In the remaining two groups, no such continuity was established. The results show that (a) experiences initially being distracting, perplexing, and confusing may indeed acquire significance for the students' possibilities of coping with the main purpose of the activity but that (b) the outcome is highly contingent on the particular experiences drawn upon by the students to cope with the distractions. Consequently, I discuss ways in which teachers may turn distractions encountered in laboratory activities into educative experiences for more than a few lucky students.

  4. The effects of distraction on metacognition and metacognition on distraction: evidence from recognition memory

    PubMed Central

    Beaman, C. Philip; Hanczakowski, Maciej; Jones, Dylan M.

    2014-01-01

    The effects of auditory distraction in memory tasks have, to date, been examined with procedures that minimize participants’ control over their own memory processes. Surprisingly little attention has been paid to metacognitive control factors which might affect memory performance. In this study, we investigate the effects of auditory distraction on metacognitive control of memory, examining the effects of auditory distraction in recognition tasks utilizing the metacognitive framework of Koriat and Goldsmith (1996), to determine whether strategic regulation of memory accuracy is impacted by auditory distraction. Results replicated previous findings in showing that auditory distraction impairs memory performance in tasks minimizing participants’ metacognitive control (forced-report test). However, the results revealed also that when metacognitive control is allowed (free-report tests), auditory distraction impacts upon a range of metacognitive indices. In the present study, auditory distraction undermined accuracy of metacognitive monitoring (resolution), reduced confidence in responses provided and, correspondingly, increased participants’ propensity to withhold responses in free-report recognition. Crucially, changes in metacognitive processes were related to impairment in free-report recognition performance, as the use of the “don’t know” option under distraction led to a reduction in the number of correct responses volunteered in free-report tests. Overall, the present results show how auditory distraction exerts its influence on memory performance via both memory and metamemory processes. PMID:24860543

  5. Reflections of distraction in memory: transfer of previous distraction improves recall in younger and older adults.

    PubMed

    Thomas, Ruthann C; Hasher, Lynn

    2012-01-01

    Three studies explored whether younger and older adults' free recall performance can benefit from prior exposure to distraction that becomes relevant in a memory task. Participants initially read stories that included distracting text. Later, they studied a list of words for free recall, with half of the list consisting of previously distracting words. When the memory task was indirect in its use of distraction (Study 1), only older adults showed transfer, with better recall of previously distracting compared with new words, which increased their recall to match that of younger adults. However, younger adults showed transfer when cued about the relevance of previous distraction both before studying the words (Study 2) and before recalling the words (Study 3) in the memory test. Results suggest that both younger and older adults encode distraction, but younger adults require explicit cueing to use their knowledge of distraction. In contrast, older adults transfer knowledge of distraction in both explicitly cued and indirect memory tasks. Results are discussed in terms of age differences in inhibition and source-constrained retrieval. PMID:21843024

  6. Assessment of distraction from erotic stimuli by nonerotic interference.

    PubMed

    Anderson, Alex B; Hamilton, Lisa Dawn

    2015-01-01

    Distraction from erotic cues during sexual encounters is a major contributor to sexual difficulties in men and women. Being able to assess distraction in studies of sexual arousal will help clarify underlying contributions to sexual problems. The current study aimed to identify the most accurate assessment of distraction from erotic cues in healthy men (n = 29) and women (n = 38). Participants were assigned to a no distraction, low distraction, or high distraction condition. Distraction was induced using an auditory distraction task presented during the viewing of an erotic video. Attention to erotic cues was assessed using three methods: a written quiz, a visual quiz, and a self-reported distraction measure. Genital and psychological sexual responses were also measured. Self-reported distraction and written quiz scores most accurately represented the level of distraction present, while self-reported distraction also corresponded with a decrease in genital arousal. Findings support the usefulness of self-report measures in conjunction with a brief quiz on the erotic material as the most accurate and sensitive ways to simply measure experimentally-induced distraction. Insight into distraction assessment techniques will enable evaluation of naturally occurring distraction in patients suffering from sexual problems. PMID:24611908

  7. Bacteria in chronic maxillary sinusitis.

    PubMed

    Karma, P; Jokipii, L; Sipilä, P; Luotonen, J; Jokipii, A M

    1979-07-01

    Sixty-one chronically inflamed maxillary sinuses produced 131 bacterial strains from mucosal pieces that were taken during a Caldwell-Luc operation and cultured aerobically and anaerobically. Sinus secretions showed only 62 and nasal secretions 106 bacterial strains. Fourteen mucosal strains, including 11 Haemophilus influenzae, grew heavily. None of 24 mucosal anaerobes showed heavy growth. Of 52 antral mucosae with culturable bacteria, 37 disclosed mixed and 15 pure growth. The bacteriological characteristics of the diseased sinus and the nose did not correlate. The duration or extent of the disease, the macroscopic appearance of the diseased sinus, or the presence or absence of allergy were unrelated to bacteriological findings, except that H influenzae was concentrated in purulent sinuses. Intraoperative culture of antral mucosa seems to give the most reliable picture of the bacteriological condition in chronic maxillary sinusitis. PMID:313206

  8. Special considerations in distracted driving with teens.

    PubMed

    Durbin, Dennis R; McGehee, Daniel V; Fisher, Donald; McCartt, Anne

    2014-01-01

    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

  9. Special Considerations in Distracted Driving with Teens

    PubMed Central

    Durbin, Dennis R; McGehee, Daniel V; Fisher, Donald; McCartt, Anne

    2014-01-01

    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

  10. Distraction from emotional information reduces biased judgements.

    PubMed

    Lench, Heather C; Bench, Shane W; Davis, Elizabeth L

    2016-06-01

    Biases arising from emotional processes are some of the most robust behavioural effects in the social sciences. The goal of this investigation was to examine the extent to which the emotion regulation strategy of distraction could reduce biases in judgement known to result from emotional information. Study 1 explored lay views regarding whether distraction is an effective strategy to improve decision-making and revealed that participants did not endorse this strategy. Studies 2-5 focused on several established, robust biases that result from emotional information: loss aversion, desirability bias, risk aversion and optimistic bias. Participants were prompted to divert attention away from their feelings while making judgements, and in each study this distraction strategy resulted in reduced bias in judgement relative to control conditions. The findings provide evidence that distraction can improve choice across several situations that typically elicit robustly biased responses, even though participants are not aware of the effectiveness of this strategy. PMID:25787937

  11. Temperament, Distraction, and Learning in Toddlerhood

    PubMed Central

    Dixon, Wallace E.; Salley, Brenda J.; Clements, Andrea D.

    2006-01-01

    The word and non-word learning abilities of toddlers were tested under various conditions of environmental distraction, and evaluated with respect to children’s temperamental attentional focus. Thirty-nine children and their mothers visited the lab at child age 21-months, where children were exposed to fast-mapping word learning trials and nonlinguistic sequential learning trials. It was found that both word and nonword-learning was adversely affected by the presentation of environmental distractions. But it was also found that the effect of the distractions sometimes depended on children’s level of attentional focus. Specifically, children high in attentional focus were less affected by environmental distractions than children low in attentional focus when attempting to learn from a model, whereas children low in attentional focus demonstrated little learning from the model. Translationally, these results may be of use to child health-care providers investigating possible sources of cognitive and language delay. PMID:17138290

  12. The Biobasis for Distraction and Dyslexia.

    ERIC Educational Resources Information Center

    Buckley, Robert E.

    1981-01-01

    The article examines the neurological basis for hyperactivity/distraction and dyslexia. Overlapping symptoms are listed, nutritional and organic basis for hyperkinesis considered, and visual and motoric factors in dyslexia discussed. (CL)

  13. Sustained Efficacy of Virtual Reality Distraction

    PubMed Central

    Rutter, Charles E.; Dahlquist, Lynnda M.; Weiss, Karen E.

    2011-01-01

    The current study tested whether the effectiveness of distraction using virtual reality (VR) technology in reducing cold pressor pain would maintain over the course of eight weekly exposures. Twenty-eight adults, 18 to 23 years of age, underwent one baseline cold pressor trial and one VR distraction trial in randomized order each week. VR distraction led to significant increases in pain threshold and pain tolerance, and significant decreases in pain intensity, time spent thinking about pain, and self-reported anxiety, relative to baseline. Repeated exposure did not appear to affect the benefits of VR. Implications for the long-term use of VR distraction as a non-pharmacological analgesic are discussed. PMID:19231295

  14. Zurich pediatric distractor for ramal condylar unit distraction in temporomandibular joint ankylosis.

    PubMed

    Sahoo, Brig N K; Roy, I D; Sharma, Rohit; Kaur, Maj Preeti

    2016-01-01

    Temporomandibular joint (TMJ) Ankylosis is an extremely disabling condition characterized by difficulty or inability to open the mouth resulting in facial asymmetry, malocclusion and dental problems. Surgical excision of the ankylosed mass is the only treatment option available to gain mouth opening. The loss in vertical height of ramus following release of ankylosis is difficult to manage in both unilateral and bilateral TMJ ankylosis. Out of all the methods to restore this height Distraction Osteogenesis (DO) is gaining popularity because of predictable gain in the length without any associated morbidity. Recurrent bilateral TMJ ankylosis in a 32 year old male was treated by osteoarthrectomy and temporal fascia interpositioning arthroplasty. Bilateral reconstruction of ramal condylar unit (RCU) was carried out by Zurich paediatric distractor (KLS Martin, Tuttlingen Germany). Following a latency period of 7 days distraction was carried out at a rate of 1mm/day for 8 days. Distractors were removed after 12 weeks of consolidation period. The case was followed up for 12 months during which the mouth opening was maintained at 38 mm and there was no anterior open bite. PMID:27563617

  15. Zurich pediatric distractor for ramal condylar unit distraction in temporomandibular joint ankylosis

    PubMed Central

    Sahoo, Brig N. K.; Roy, I. D.; Sharma, Rohit; Kaur, Maj Preeti

    2016-01-01

    Temporomandibular joint (TMJ) Ankylosis is an extremely disabling condition characterized by difficulty or inability to open the mouth resulting in facial asymmetry, malocclusion and dental problems. Surgical excision of the ankylosed mass is the only treatment option available to gain mouth opening. The loss in vertical height of ramus following release of ankylosis is difficult to manage in both unilateral and bilateral TMJ ankylosis. Out of all the methods to restore this height Distraction Osteogenesis (DO) is gaining popularity because of predictable gain in the length without any associated morbidity. Recurrent bilateral TMJ ankylosis in a 32 year old male was treated by osteoarthrectomy and temporal fascia interpositioning arthroplasty. Bilateral reconstruction of ramal condylar unit (RCU) was carried out by Zurich paediatric distractor (KLS Martin, Tuttlingen Germany). Following a latency period of 7 days distraction was carried out at a rate of 1mm/day for 8 days. Distractors were removed after 12 weeks of consolidation period. The case was followed up for 12 months during which the mouth opening was maintained at 38 mm and there was no anterior open bite.

  16. Infant Mandibular Distraction for Upper Airway Obstruction: A Clinical Audit

    PubMed Central

    Adhikari, Ashim N.; Heggie, Andrew A.C.; Shand, Jocelyn M.; Bordbar, Patrishia; Pellicano, Anastasia

    2016-01-01

    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

  17. Establishing the Attention-Distractibility Trait.

    PubMed

    Forster, Sophie; Lavie, Nilli

    2016-02-01

    Failures to focus attention will affect any task engagement (e.g., at work, in the classroom, when driving). At the clinical end, distractibility is a diagnostic criterion of attention-deficit/hyperactivity disorder (ADHD). In this study, we examined whether the inability to maintain attentional focus varies in the overall population in the form of an attention-distractibility trait. To test this idea, we administered an ADHD diagnostic tool to a sample of healthy participants and assessed the relationship between ADHD symptoms and task distraction. ADHD symptom summary scores were significantly positively associated with distractor interference in letter-search and name-classification tasks (as measured by reaction time), as long as the distractors were irrelevant (cartoon images) rather than relevant (i.e., compatible or incompatible with target names). Higher perceptual load during a task eliminated distraction irrespective of ADHD score. These findings suggest the existence of an attention-distractibility trait that confers vulnerability to irrelevant distraction, which can be remedied by increasing the level of perceptual load during the task. PMID:26667659

  18. A Novel Technique Using Customized Headgear for Fixation of Rigid External Distraction Device in an Infant With Crouzon Syndrome.

    PubMed

    Hariri, Firdaus; Rahman, Zainal Ariff Abdul; Mahdah, Saridah; Mathaneswaran, Vickneswaran; Ganesan, Dharmendra

    2015-11-01

    Rigid external distraction device is often indicated for superior midfacial advancement in pediatric syndromic craniosynostosis patients. Even though the technique is proven reliable to treat the functional issues related to the craniofacial deformity, major complications associated with its fixation, such as intracranial pin perforation and migration have been reported. We report a novel technique of using a customized headgear to prevent intracranial pin perforation over a very thin temporal bone region in an 8-month-old infant with Crouzon syndrome who underwent monobloc Le Fort III distraction osteogenesis using a combination of bilateral internal and a rigid external distraction device. The customized headgear provides a protective platform at the temporal region thus preventing intracranial pin perforation and allows stable fixation during the early phase of consolidation period to prevent central component relapse. The headgear can be used short term when rigid external distractor is indicated in infant patient but requires close monitoring because of risks of skin necrosis and temporal region indentation. PMID:26594993

  19. Skeletal and dental stability of segmental distraction of the anterior mandibular alveolar process. A 2-year follow-up.

    PubMed

    Joss, C U; Triaca, A; Antonini, M; Kiliaridis, S; Kuijpers-Jagtman, A M

    2012-05-01

    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. PMID:22356741

  20. Maxillary First Molar with Two Root Canals

    PubMed Central

    Rahimi, Saeed; Ghasemi, Negin

    2013-01-01

    Knowledge regarding the anatomic morphology of maxillary molars is absolutely essential for the success of endodontic treatment. The morphology of the permanent maxillary first molar has been reviewed extensively; however, the presence of two canals in a two-rooted maxillary first molar has rarely been reported in studies describing tooth and root canal anatomies. This case report presents a patient with a maxillary first molar with two roots and two root canals, who was referred to the Department of Endodontics, Tabriz University of Medical Sciences, Iran. PMID:23862051

  1. Reflections of Distraction in Memory: Transfer of Previous Distraction Improves Recall in Younger and Older Adults

    ERIC Educational Resources Information Center

    Thomas, Ruthann C.; Hasher, Lynn

    2012-01-01

    Three studies explored whether younger and older adults' free recall performance can benefit from prior exposure to distraction that becomes relevant in a memory task. Participants initially read stories that included distracting text. Later, they studied a list of words for free recall, with half of the list consisting of previously distracting…

  2. Formation of ectopic osteogenesis in weightlessness

    NASA Technical Reports Server (NTRS)

    1977-01-01

    An ectopic osteogenesis experiment aboard the Cosmos-936 biosatellite is described. Decalcified, lyophilized femur and tibia were implanted under the fascia or in the anterior wall of the abdomen in rats. Bone formation before and after the tests is described and illustrated. The extent of formation of ectopic bone in weightlessness did not differ significantly from that in the ground controls, but the bone marrow of the ectopic bone of the flight rats consisted exclusively of fat cells. The deficit of support-muscle loading was considered to cause the disturbance in skeletal bone tissue development.

  3. Unusual external resorption of a maxillary lateral.

    PubMed

    Giunta, J L; Kaplan, M A

    1994-01-01

    This article defines an unusual previously unreported entity afflicting a maxillary lateral incisor. Labial idiopathic external root resorption just apical to the cemento-enamel presented as a gingival (periodontal) problem and was misinterpreted as cervical dental caries. This report defines a new possibility for a radicular defect in a maxillary lateral incisor that may cause periodontal problems. PMID:8054293

  4. Maxillary sinusitis with pulmonary tuberculosis

    PubMed Central

    Upadhyay, Rashmi; Prakash, Ved; Singh, Abhishek Bahadur; Saheer, S

    2014-01-01

    Tubercular infection of the nasal cavity is an infrequently encountered condition. More so, after the discovery of relevant antibiotics, nasal sinus tuberculosis is not commonly seen. Few cases have reported tuberculosis of the paranasal sinuses, nasopharynx and larynx. With the increasing incidence of HIV, these rare forms of infection have started re-emerging. We present a case of a middle aged man presenting with nasal cavity lesion along with pulmonary tuberculosis, which came to light only after the diagnosis of maxillary sinus tuberculosis. PMID:25085948

  5. Happiness increases distraction by auditory deviant stimuli.

    PubMed

    Pacheco-Unguetti, Antonia Pilar; Parmentier, Fabrice B R

    2016-08-01

    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. PMID:26302716

  6. Surgically assisted rapid maxillary expansion in adults.

    PubMed

    Pogrel, M A; Kaban, L B; Vargervik, K; Baumrind, S

    1992-01-01

    Twelve adults with maxillary width discrepancy of greater than 5 mm were treated by surgically assisted rapid maxillary expansion. The procedure consisted of bilateral zygomatic buttress and midpalatal osteotomies combined with the use of a tooth-borne orthopedic device postoperatively. Mean palatal expansion of 7.5 mm (range of 6 to 13 mm), measured in the first molar region, was achieved within 3 weeks in all patients. Expansion remained stable during the 12-month study period, with a mean relapse for the entire group of 0.88 +/- 0.48 mm. Morbidity was limited to mild postoperative discomfort. The results of this preliminary study indicated that surgically assisted rapid maxillary expansion is a safe, simple, and reliable procedure for achieving a permanent increase in skeletal maxillary width in adults. Further study is necessary to document the three-dimensional movements of the maxillary segments and long-term stability of the skeletal and dental changes. PMID:1453038

  7. The Interfering Effect of Distracting Stimuli on the Infant's Memory

    ERIC Educational Resources Information Center

    McCall, Robert B.; And Others

    1977-01-01

    Infants 3 1/2 months of age were assessed for the possible role of the dissimilarity of the distracting stimulus to the originally learned standard in a modified familiarization-distraction-test paradigm. (Author/JMB)

  8. Odontogenic maxillary sinusitis: a review.

    PubMed

    Simuntis, Regimantas; Kubilius, Ričardas; Vaitkus, Saulius

    2014-01-01

    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. PMID:25209225

  9. Distracted driving: prevalence, problems, and prevention.

    PubMed

    Overton, Tiffany L; Rives, Terry E; Hecht, Carrie; Shafi, Shahid; Gandhi, Rajesh R

    2015-01-01

    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. PMID:24499372

  10. Distraction can reduce age-related forgetting.

    PubMed

    Biss, Renée K; Ngo, K W Joan; Hasher, Lynn; Campbell, Karen L; Rowe, Gillian

    2013-04-01

    In three experiments, we assessed whether older adults' generally greater tendency to process distracting information can be used to minimize widely reported age-related differences in forgetting. Younger and older adults studied and recalled a list of words on an initial test and again on a surprise test after a 15-min delay. In the middle (Experiments 1a and 2) or at the end (Experiment 3) of the delay, participants completed a 1-back task in which half of the studied words appeared as distractors. Across all experiments, older adults reliably forgot unrepeated words; however, older adults rarely or never forgot the words that had appeared as distractors, whereas younger adults forgot words in both categories. Exposure to distraction may serve as a rehearsal episode for older adults, and thus as a method by which general distractibility may be co-opted to boost memory. PMID:23426890

  11. A rare combination of amniotic constriction band with osteogenesis imperfecta.

    PubMed

    Shah, Krupa Hitesh; Shah, Hitesh

    2015-01-01

    Amniotic constriction bands and osteogenesis imperfecta are disorders arising from a collagen defect. We report a rare association of amniotic bands with osteogenesis imperfecta in a child. The child was born with multiple amniotic bands involving the right leg, both hands and both feet. Multiple fractures of long bones of lower limbs occurred in childhood due to trivial trauma. Deformities of the femur and tibia due to malunion with osteopenia and blue sclerae were present. The patient was treated with z plasty of constriction band of the right tibia and bisphosphonate for osteogenesis imperfecta. This rare association of both collagen diseases may provide further insight for the pathogenesis of these diseases. PMID:26561227

  12. Sadness increases distraction by auditory deviant stimuli.

    PubMed

    Pacheco-Unguetti, Antonia P; Parmentier, Fabrice B R

    2014-02-01

    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. PMID:24098923

  13. The Effects of Distraction on Cognitive Task Performance during Toddlerhood

    ERIC Educational Resources Information Center

    Wyss, Nancy M.; Kannass, Kathleen N.; Haden, Catherine A.

    2013-01-01

    We investigated the effects of distraction on attention and task performance during toddlerhood. Thirty toddlers (24- to 26-month-olds) completed different tasks (2 of each: categorization, problem solving, memory, free play) in one of two conditions: No Distraction or Distraction. The results revealed that the distractor had varying effects on…

  14. Distractibility in Learning Disabled Children: The Role of Measurement Artifact.

    ERIC Educational Resources Information Center

    Harvey, Philip D.; And Others

    Two digit span distraction tasks were used to compare performance of 32 learning disabled (LD) and 32 normal children (mean ages 16 and 15 years). On the first set of tasks, where the neutral and distraction conditions were matched for their ability to discriminate between groups, no differential distraction effect was found. The second task's…

  15. Unusual Anatomy of Maxillary Second Premolars

    PubMed Central

    de Almeida-Gomes, Fábio; de Sousa, Bruno Carvalho; de Souza, Fabricio Dias; dos Santos, Roberto Alves; Maniglia-Ferreira, Cláudio

    2009-01-01

    In this study, endodontic treatments of maxillary second premolars with unusual anatomical configuration were presented. Maxillary second premolars usually have one root with one or two root canals. The occurrence of variations in anatomical configuration is also common; therefore, it must be taken into account in clinical and radiographic evaluation during the endodontic treatment. These teeth may also require special shaping and filling techniques. This article reports and discusses the treatment recommendations for unusual occurrences of anatomical configurations in four different maxillary second premolars. PMID:19421396

  16. Evaluation of canine retraction following periodontal distraction using NiTi coil spring and implants – A clinical study

    PubMed Central

    Khanna, Rohit; Tikku, Tripti; Sachan, Kiran; Maurya, R.P.; Verma, Geeta; Ojha, Vivek

    2014-01-01

    Objective To evaluate the amount of canine retraction with periodontal distraction using miniscrew implants and NiTi coil spring. Material and method Sample comprised of 25 patients who were scheduled for all 1st premolar extraction (13 males and 12 females), in the age range of 16–22 years with mean age 18.8 ± 2.7 years. For each patient left side served as control side (Group I) and right side as experimental side (Group II). At the time of first premolar extraction, periodontal distraction was performed only on the experimental side, followed by retraction of canine from mini-implant by closed NiTi coil spring on both the sides. “Nemotech” software was used to evaluate the amount of canine retraction for a period of 3 months. Results Significantly higher amount of tooth movement was seen from T0–T1 and from T1–T2 in Group II for the maxillary parameters 3C-5C, 6CF-3C, 3C-I/3C-J and for the mandibular parameter 6CF″-3C″. Whereas no significant amount of tooth movement was observed for maxillary and mandibular parameters between T2-T3 except for 6CF″-3C″ (p ≤ 0.01) which was significantly higher for the Group II. Conclusion There was accelerated canine retraction on the periodontal distraction side as compared to the control side, with negligible anchorage loss. PMID:25737943

  17. How Do Health Care Providers Diagnose Osteogenesis Imperfecta?

    MedlinePlus

    ... Information Clinical Trials Resources and Publications How do health care providers diagnose osteogenesis imperfecta (OI)? Skip sharing on ... Page Content If OI is moderate or severe, health care providers usually diagnose it during prenatal ultrasound at ...

  18. IFITM5 mutations and osteogenesis imperfecta.

    PubMed

    Hanagata, Nobutaka

    2016-03-01

    Interferon-induced transmembrane protein 5 (IFITM5) is an osteoblast-specific membrane protein that has been shown to be a positive regulatory factor for mineralization in vitro. However, Ifitm5 knockout mice do not exhibit serious bone abnormalities, and thus the function of IFITM5 in vivo remains unclear. Recently, a single point mutation (c.-14C>T) in the 5' untranslated region of IFITM5 was identified in patients with osteogenesis imperfecta type V (OI-V). Furthermore, a single point mutation (c.119C>T) in the coding region of IFITM5 was identified in OI patients with more severe symptoms than patients with OI-V. Although IFITM5 is not directly involved in the formation of bone in vivo, the reason why IFITM5 mutations cause OI remains a major mystery. In this review, the current state of knowledge of OI pathological mechanisms due to IFITM5 mutations will be reviewed. PMID:26031935

  19. [Orthotic management for patients with osteogenesis imperfecta].

    PubMed

    Alguacil Diego, I M; Molina Rueda, F; Gómez Conches, M

    2011-02-01

    Osteogenesis imperfecta (OI) is a disease caused by a genetic defect in the qualitative and quantitative synthesis of type I collagen. There is a wide variation in its clinical signs, characterized by bone fragility, resulting in a bone vulnerable to external and internal forces, determining the occurrence of frequent fractures with minimal or no trauma. The therapeutic objective is directed to improve the functional capacity of the child or adult concerned, adopting those compensatory strategies to optimise their independence. In this sense, the use of different orthoses and assistive technology are important for achieving these objectives. We reviewed the main contributions to this orthotic disease and the evolution of the different devices used in different databases over the last 25 years. PMID:20880764

  20. The Neural Bases of Distraction and Reappraisal

    ERIC Educational Resources Information Center

    McRae, Kateri; Hughes, Brent; Chopra, Sita; Gabrieli, John D. E.; Gross, James J.; Ochsner, Kevin N.

    2010-01-01

    Distraction and reappraisal are two commonly used forms of cognitive emotion regulation. Functional neuroimaging studies have shown that each one depends upon interactions between pFC, interpreted as implementing cognitive control, and limbic regions, interpreted as mediating emotional responses. However, no study has directly compared distraction…

  1. Reward, Distraction, and the Overjustification Effect

    ERIC Educational Resources Information Center

    Smith, Timothy W.; Pittman, Thane S.

    1978-01-01

    This study tests two differing hypotheses: the competing response hypothesis, which states that both reward and non-reward distractions produce decreases in interest which weaken over repeated trials, and the attribution/overjustification hypothesis, which maintains that rewards produce a decrease in interest that does not weaken over trials.…

  2. 77 FR 51610 - Distracted Driving Grant Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-24

    ... National Highway Traffic Safety Administration Distracted Driving Grant Program AGENCY: Department of... amount of $17.525 million in Federal fiscal year (FY) 2013 funds to provide grants to States for enacting... limitation that may be established in appropriations law. Therefore, the amount available for the grants...

  3. Interference from audio distracters during speechreading

    NASA Astrophysics Data System (ADS)

    Brungart, Douglas S.; Simpson, Brian D.

    2005-12-01

    Although many audio-visual speech experiments have focused on situations where the presence of an incongruent visual speech signal influences the perceived utterance heard by an observer, there are also documented examples of a related effect in which the presence of an incongruent audio speech signal influences the perceived utterance seen by an observer. This study examined the effects that different distracting audio signals had on performance in a color and number keyword speechreading task. When the distracting sound was noise, time-reversed speech, or continuous speech, it had no effect on speechreading. However, when the distracting audio signal consisted of speech that started at the same time as the visual stimulus, speechreading performance was substantially degraded. This degradation did not depend on the semantic similarity between the target and masker speech, but it was substantially reduced when the onset of the audio speech was shifted relative to that of the visual stimulus. Overall, these results suggest that visual speech perception is impaired by the presence of a simultaneous mismatched audio speech signal, but that other types of audio distracters have little effect on speechreading performance.

  4. Clinical and radiographic evaluation of maxillary central incisors exposure in patients undergoing maxillary advancement

    PubMed Central

    Trento, Guilherme dos Santos; Bernabé, Felipe Bueno Rosettti; da Costa, Delson João; Rebellato, Nelson Luis Barbosa; Klüppel, Leandro Eduardo; Scariot, Rafaela

    2015-01-01

    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

  5. Dynamics of Driver Distraction: The process of engaging and disengaging

    PubMed Central

    Lee, John D.

    2014-01-01

    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

  6. Virtual Reality: A Distraction Intervention for Chemotherapy

    PubMed Central

    Schneider, Susan M.; Hood, Linda E.

    2007-01-01

    Purpose/Objectives To explore virtual reality (VR) as a distraction intervention to relieve symptom distress in adults receiving chemotherapy treatments for breast, colon, and lung cancer. Design Crossover design in which participants served as their own control. Setting Outpatient clinic at a comprehensive cancer center in the southeastern United States. Sample 123 adults receiving initial chemotherapy treatments. Methods Participants were randomly assigned to receive the VR distraction intervention during one chemotherapy treatment and then received no intervention (control) during an alternate matched chemotherapy treatment. The Adapted Symptom Distress Scale–2, Revised Piper Fatigue Scale, and State Anxiety Inventory were used to measure symptom distress. The Presence Questionnaire and an open-ended questionnaire were used to evaluate the subjects’ VR experience. The influence of type of cancer, age, and gender on symptom outcomes was explored. Mixed models were used to test for differences in levels of symptom distress. Main Research Variables Virtual reality and symptom distress. Findings Patients had an altered perception of time (p < 0.001) when using VR, which validates the distracting capacity of the intervention. Evaluation of the intervention indicated that patients believed the head-mounted device was easy to use, they experienced no cybersickness, and 82% would use VR again. However, analysis demonstrated no significant differences in symptom distress immediately or two days following chemotherapy treatments. Conclusions Patients stated that using VR made the treatment seem shorter and that chemotherapy treatments with VR were better than treatments without the distraction intervention. However, positive experiences did not result in a decrease in symptom distress. The findings support the idea that using VR can help to make chemotherapy treatments more tolerable, but clinicians should not assume that use of VR will improve chemotherapy

  7. Maxillary sinus manifestations of methamphetamine abuse.

    PubMed

    Faucett, Erynne A; Marsh, Katherine M; Farshad, Kayven; Erman, Audrey B; Chiu, Alexander G

    2015-01-01

    Methamphetamines are the second most commonly used illicit drug worldwide and cost the United States health-care system ∼$23.4 billion annually. Use of this drug affects multiple organ systems and causes a variety of clinical manifestations. Although there are commonly known sequelae of methamphetamine abuse such as "meth mouth," there is limited evidence regarding maxillary sinus manifestations. The following cases highlight the initial evaluation and management of two methamphetamine abusers with loculated purulent collections within the maxillary sinus as a result of methamphetamine abuse. Our aim was to delineate the otolaryngologic symptoms associated with the patients' methamphetamine abuse. Computed tomography and magnetic resonance imaging studies revealed loculated purulent collections within the maxillary sinus of probable odontogenic origin in both patients. Methamphetamine abuse leading to rampant caries and poor oral hygiene may predispose individuals for craniofacial infections and fluid collections. These cases illustrate the development of maxillary sinusitis and maxilla mucoceles that have been associated with methamphetamine use. PMID:25675268

  8. A benign maxillary tumour with malignant features.

    PubMed

    Ricalde, Rosario R; Lim, Aimee Caroline E; Lopa, Ramon Antonio B; Carnate, Jose M

    2010-06-01

    Non-specific biopsy results such as chronic inflammation, hemorrhage, necrosis can be frustrating to the clinician. This is especially true if the patient presents with clinical features suggestive of an aggressive tumour. This is a review of the clinical features, diagnostic dilemmas and surgical management of a benign maxillary mass with malignant features - a disease called hematoma-like mass of the maxillary sinus (HLMMS). Our experience with five cases will also be cited. PMID:20502750

  9. Distractibility in Learning-Disabled Children: The Role of Measurement Artifact.

    ERIC Educational Resources Information Center

    Harvey, Philip D.; And Others

    1984-01-01

    Two-digit span tasks compared the distraction performance of 32 learning disabled (LD) high schoolers and non LD Ss. No differential distraction effect was found on the first set (matching nondistraction and distraction conditions). In set two, (distraction condition was designed to be more discriminating), a differential distraction effect was…

  10. Biomechanical patterns of text-message distraction.

    PubMed

    Le, Peter; Hwang, Jaejin; Grawe, Sarah; Li, Jing; Snyder, Alison; Lee, Christina; Marras, William S

    2015-01-01

    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. PMID:25867196

  11. Skeletal and dental stability of segmental distraction of the anterior mandibular alveolar process. A 5.5-year follow-up.

    PubMed

    Joss, C U; Triaca, A; Antonini, M; Kiliaridis, S; Kuijpers-Jagtman, A M

    2013-03-01

    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. PMID:23153785

  12. Sharing the responsibility for driver distraction across road transport systems: a systems approach to the management of distracted driving.

    PubMed

    Young, Kristie L; Salmon, Paul M

    2015-01-01

    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. PMID:24767853

  13. MicroRNAs regulate osteogenesis and chondrogenesis

    SciTech Connect

    Dong, Shiwu; Yang, Bo; Guo, Hongfeng; Kang, Fei

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer To focus on the role of miRNAs in chondrogenesis and osteogenesis. Black-Right-Pointing-Pointer Involved in the regulation of miRNAs in osteoarthritis. Black-Right-Pointing-Pointer To speculate some therapeutic targets for bone diseases. -- Abstract: MicroRNAs (miRNAs) are a class of small molecules and non-coding single strand RNAs that regulate gene expression at the post-transcriptional level by binding to specific sequences within target genes. miRNAs have been recognized as important regulatory factors in organism development and disease expression. Some miRNAs regulate the proliferation and differentiation of osteoblasts, osteoclasts and chondrocytes, eventually influencing metabolism and bone formation. miRNAs are expected to provide potential gene therapy targets for the clinical treatment of metabolic bone diseases and bone injuries. Here, we review the recent research progress on the regulation of miRNAs in bone biology, with a particular focus on the miRNA-mediated control mechanisms of bone and cartilage formation.

  14. Post microtextures accelerate cell proliferation and osteogenesis.

    PubMed

    Kim, Eun Jung; Boehm, Cynthia A; Mata, Alvaro; Fleischman, Aaron J; Muschler, George F; Roy, Shuvo

    2010-01-01

    The influence of surface microtexture on osteogenesis was investigated in vitro by examining the proliferation and differentiation characteristics of a class of adult stem cells and their progeny, collectively known as connective tissue progenitor cells (CTPs). Human bone marrow-derived CTPs were cultured for up to 60 days on smooth polydimethylsiloxane (PDMS) surfaces and on PDMS with post microtextures that were 10 microm in diameter and 6 microm in height, with 10 microm separation. DNA quantification revealed that the numbers of CTPs initially attached to both substrates were similar. However, cells on microtextured PDMS transitioned from lag phase after 4 days of culture, in contrast to 6 days for cells on smooth surfaces. By day 9 cells on the smooth surfaces exhibited arbitrary flattened shapes and migrated without any preferred orientation. In contrast, cells on the microtextured PDMS grew along the array of posts in an orthogonal manner. By days 30 and 60 cells grew and covered all surfaces with extracellular matrix. Western blot analysis revealed that the expression of integrin alpha5 was greater on the microtextured PDMS compared with smooth surfaces. Real time reverse transcription-polymerase chain reaction revealed that gene expression of alkaline phosphatase had decreased by days 30 and 60, compared with that on day 9, for both substrates. Gene expression of collagen I and osteocalcin was consistently greater on post microtextures relative to smooth surfaces at all time points. PMID:19539062

  15. Post microtextures accelerate cell proliferation and osteogenesis

    PubMed Central

    Kim, Eun Jung; Boehm, Cynthia A.; Mata, Alvaro; Fleischman, Aaron J.; Muschler, George F.; Roy, Shuvo

    2013-01-01

    The influence of surface microtexture on osteogenesis was investigated in vitro by examining the proliferation and differentiation characteristics of a class of adult stem cells and their progeny, collectively known as connective tissue progenitor cells (CTPs). Human bone marrow-derived CTPs were cultured for up to 60 days on smooth polydimethylsiloxane (PDMS) surfaces and on PDMS with post microtextures that were 10 µm in diameter and 6 µm in height, with 10 µm separation. DNA quantification revealed that the numbers of CTPs initially attached to both substrates were similar. However, cells on microtextured PDMS transitioned from lag phase after 4 days of culture, in contrast to 6 days for cells on smooth surfaces. By day 9 cells on the smooth surfaces exhibited arbitrary flattened shapes and migrated without any preferred orientation. In contrast, cells on the microtextured PDMS grew along the array of posts in an orthogonal manner. By days 30 and 60 cells grew and covered all surfaces with extracellular matrix. Western blot analysis revealed that the expression of integrin α5 was greater on the microtextured PDMS compared with smooth surfaces. Real time reverse transcription-polymerase chain reaction revealed that gene expression of alkaline phosphatase had decreased by days 30 and 60, compared with that on day 9, for both substrates. Gene expression of collagen I and osteocalcin was consistently greater on post microtextures relative to smooth surfaces at all time points. PMID:19539062

  16. [An experimental study of a new bidirectional distraction appliance].

    PubMed

    Lucas, R; Gounot, N; Cresseaux, P; Breton, P; Freidel, M; Ferez, C; Roger, T; Genevois, J P

    1998-07-01

    The goals of mandibular distraction are to restore a normal length but also a normal shape to the hypoplastic mandible. These two goals are related to the elongation vector which is itself related to the location of the cortictomy and of the device. Other factors influence this elongation vector. So it is impossible to precisely predict the elongation vector. With the monodirectional distraction device no modification can be made during the distraction time. With a bidirectional distraction device offering the possibility to modulate the angulation between the two elongation rods it is possible to adjust the elongation vector during distraction. Precise distraction gap modeling is possible. This is particularly important to correct anterior open-bite. This device was tested on animals (pigs). PMID:9697234

  17. Strategies for preventing distractions and interruptions in the OR.

    PubMed

    Clark, Gregory J

    2013-06-01

    Stakeholders in the automotive industry, airline industry, and anesthesia profession have identified critical periods of time in which distractions and interruptions of normal processes can have devastating effects. Just as reducing distractions improves safety in an automobile or airplane cockpit, limiting distractions and interruptions during critical times in the perioperative setting can increase patient safety. We assessed perioperative nurses and identified what they perceived as critical phases of nursing care. We also worked with our anesthesia partners to address their concerns about interruptions during the administration of nerve blocks. The perioperative nurses at our hospital initiated strategies to reduce distractions or interruptions to their practice at critical points, and, in collaboration with surgical committee members, we developed strategies to reduce or eliminate distractions for anesthesia professionals during the preoperative administration of nerve blocks and to eliminate distractions for the RN circulator and scrub person during the final counts. PMID:23722034

  18. Method for Automated Bone Shape Correction within Bone Distraction Procedure

    NASA Astrophysics Data System (ADS)

    Blynskiy, F. Yu

    2016-01-01

    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.

  19. A rare presentation of multiple dens invaginatus in maxillary dentition

    PubMed Central

    Purani, Jigar M; Purani, Hiral J

    2014-01-01

    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. PMID:25085944

  20. Inflammatory myofibroblastic tumor of the maxillary sinus related with pulp necrosis of maxillary teeth: case report.

    PubMed

    Kim, Sin-Young; Yang, Sung-Eun

    2011-11-01

    Inflammatory myofibroblastic tumor (IMT) is a benign lesion composed of myofibroblasts accompanied by varying numbers of inflammatory cells. Various pathogenetic factors have been proposed, but the etiology of most IMTs remains unknown. This article presents a case of IMT occurring in the left maxillary sinus. A 24-year-old man complained of throbbing pain in the maxillary left molars and swelling of the left cheek. His maxillary left second molar was diagnosed as pulp necrosis and root canal treatment performed. After that, his symptoms continued and he was referred to the Department of Otolaryngology. Computerized tomography disclosed compact soft tissue masses in the left maxillary sinus with obstruction of maxillary ostium. Under general anesthesia, the lesions were fully excised. Histopathologically, the lesions were composed of plump or spindled myofibroblasts. Cells were immunoreactive for smooth muscle actin and β-catenin, and were negative for ALK1, CD34, and EMA. The diagnosis was IMT of left maxillary sinus. Although it is very rare, IMT should be included as a differential diagnosis in patients with compact masses in maxillary sinus. PMID:21868269

  1. Subtractive fuzzy classifier based driver distraction levels classification using EEG.

    PubMed

    Wali, Mousa Kadhim; Murugappan, Murugappan; Ahmad, Badlishah

    2013-09-01

    [Purpose] In earlier studies of driver distraction, researchers classified distraction into two levels (not distracted, and distracted). This study classified four levels of distraction (neutral, low, medium, high). [Subjects and Methods] Fifty Asian subjects (n=50, 43 males, 7 females), age range 20-35 years, who were free from any disease, participated in this study. Wireless EEG signals were recorded by 14 electrodes during four types of distraction stimuli (Global Position Systems (GPS), music player, short message service (SMS), and mental tasks). We derived the amplitude spectrum of three different frequency bands, theta, alpha, and beta of EEG. Then, based on fusion of discrete wavelet packet transforms and fast fourier transform yield, we extracted two features (power spectral density, spectral centroid frequency) of different wavelets (db4, db8, sym8, and coif5). Mean ± SD was calculated and analysis of variance (ANOVA) was performed. A fuzzy inference system classifier was applied to different wavelets using the two extracted features. [Results] The results indicate that the two features of sym8 posses highly significant discrimination across the four levels of distraction, and the best average accuracy achieved by the subtractive fuzzy classifier was 79.21% using the power spectral density feature extracted using the sym8 wavelet. [Conclusion] These findings suggest that EEG signals can be used to monitor distraction level intensity in order to alert drivers to high levels of distraction. PMID:24259914

  2. Speech-Language Dissociations, Distractibility, and Childhood Stuttering

    PubMed Central

    Conture, Edward G.; Walden, Tedra A.; Lambert, Warren E.

    2015-01-01

    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

  3. ALCOHOL AND DISTRACTION INTERACT TO IMPAIR DRIVING PERFORMANCE

    PubMed Central

    Harrison, Emily L. R.; Fillmore, Mark T.

    2011-01-01

    Background Recognition of the risks associated with alcohol intoxication and driver distraction has led to a wealth of simulated driving research aimed at studying the adverse effects of each of these factors. Research on driving has moved beyond the individual, separate examination of these factors to the examination of potential interactions between alcohol intoxication and driver distraction. In many driving situations, distractions are commonplace and might have little or no disruptive influence on primary driving functions. Yet, such distractions might become disruptive to a driver who is intoxicated. Methods The present study examined the interactive impairing effects of alcohol intoxication and driver distraction on simulated driving performance in 40 young adult drivers using a divided attention task as a distracter activity. The interactive influence of alcohol and distraction was tested by having drivers perform the driving task under four different conditions: 0.65 g/kg alcohol; 0.65 g/kg alcohol + divided attention; placebo; and placebo + divided attention. Results As hypothesized, divided attention had no impairing effect on driving performance in sober drivers. However, under alcohol, divided attention exacerbated the impairing effects of alcohol on driving precision. Conclusions Alcohol and distraction continue to be appropriate targets for research into ways to reduce the rates of driving-related fatalities and injuries. Greater consideration of how alcohol and distraction interact to impair aspects of driving performance can further efforts to create prevention and intervention measures to protect drivers, particularly young adults. PMID:21277119

  4. Chronic maxillary sinusitis and diabetes related maxillary osteonecrosis: a case report

    PubMed Central

    2015-01-01

    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

  5. Chronic maxillary sinusitis and diabetes related maxillary osteonecrosis: a case report.

    PubMed

    Huh, Suk; Lee, Chae-Yoon; Ohe, Joo-Young; Lee, Jung-Woo; Choi, Byung-Jun; Lee, Baek-Soo; Kwon, Yong-Dae

    2015-12-01

    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

  6. Solitary Median Maxillary Central Incisor Versus Agenesis of the Maxillary Central Incisor.

    PubMed

    de Carvalho, Fabrício Kitazono; Arid, Juliana; De Rossi, Andiara; Paula-Silva, Francisco W G; Nelson-Filho, Paulo

    2016-01-01

    A solitary median maxillary central incisor (SMMCI) is rare and affected individuals may carry a potentially serious condition known as SMMCI syndrome. However, many of these cases do not receive proper attention because they are misdiagnosed as agenesis of the maxillary central incisor. The purpose of this manuscript is to report two cases of children with only one maxillary central incisor and draw diagnostic differences between the entities. A correct diagnosis is very important because if an SMMCI is confirmed, the patient should be referred for genetic counseling. PMID:27098718

  7. Instability of Polymeric Skin Collagen in Osteogenesis Imperfecta

    PubMed Central

    Francis, M. J. O.; Smith, Roger; Bauze, Robert J.

    1974-01-01

    The structural polymeric collagen of the skin of 19 patients with osteogenesis imperfecta has been examined. In those with severe bone disease, who often have white sclerae, this collagen fraction is less resistant to depolymerization than that of age-matched controls, though the total amount is normal. In patients with less severe bone disease, whose sclerae are usually blue, the polymeric collagen may have normal stability but the total amount is reduced. These results suggest defective cross-linking of collagen in severe osteogenesis imperfecta. PMID:4816854

  8. Diffusion model to describe osteogenesis within a porous titanium scaffold.

    PubMed

    Schmitt, M; Allena, R; Schouman, T; Frasca, S; Collombet, J M; Holy, X; Rouch, P

    2016-01-01

    In this study, we develop a two-dimensional finite element model, which is derived from an animal experiment and allows simulating osteogenesis within a porous titanium scaffold implanted in ewe's hemi-mandible during 12 weeks. The cell activity is described through diffusion equations and regulated by the stress state of the structure. We compare our model to (i) histological observations and (ii) experimental data obtained from a mechanical test done on sacrificed animal. We show that our mechano-biological approach provides consistent numerical results and constitutes a useful tool to predict osteogenesis pattern. PMID:25573031

  9. Prenatal diagnosis of lethal osteogenesis imperfecta in twin pregnancy.

    PubMed

    Morin, L R; Herlicoviez, M; Loisel, J C; Jacob, B; Feuilly, C; Stanescu, V

    1991-06-01

    Lethal osteogenesis imperfecta was diagnosed at 27 weeks amenorrea in one fetus of a bichorial twin pregnancy. Sonographic findings included: short-limb dwarfism, hypotrophy and hypoechoic bones. The affected fetus was so translucent that only the normal fetus could be seen on plain in utero radiography. The affected fetus died immediately after birth. Postmortem radiography and histology were typical of lethal osteogenesis imperfecta of type IIA. Aids to the etiological diagnosis of in utero dwarfism are presented. Sonographic features correlated with neonatal death are described. PMID:1863995

  10. Osteogenesis imperfecta misdiagnosed as child abuse.

    PubMed

    Singh Kocher, Mininder; Dichtel, Laura

    2011-11-01

    The differential diagnosis of child abuse includes osteogenesis imperfecta (OI). Mild phenotypes of OI may be misdiagnosed as child abuse. The purpose of this study was to review the experience of families in which OI was misdiagnosed as child abuse. Sixty-one potential cases of misdiagnosis were identified from a lay support organization. Upon review of the medical records, 33 cases were identified with a confirmed diagnosis of OI (skin biopsy or DNA blood test). Questionnaires were given to families to describe their condition and experiences. There were 19 male and 14 female children. Mean age at presentation was 7.1 months (range: 1-23 months). All patients had fractures and the presenting symptoms included pain (n=14), swelling (n=7), decreased limb movement (n=5), or unusual limb position (n=2). Abnormal radiograph findings consistent with OI were found in 19 of 33 patients (58%), clinical findings of OI were present in 23 of 33 patients (70%), and a family history that could be supportive of OI was present in 18 of 33 families (55%). Children were removed from the family in 70% of cases and older siblings were removed from the family in 62% of cases. The mean age at the time of diagnosis of OI was 10.5 months (range: 3-35 months). The consequences of misdiagnosis of OI as child abuse are devastating to the family. OI should be considered in all cases of suspected child abuse. In children with any clinical, radiographic, or family history features of OI, early involvement of a bone specialist and performance of laboratory testing should be considered to establish a timely and accurate diagnosis. PMID:21716141

  11. Effects of Auditory Distraction on Cognitive Processing of Young Adults

    ERIC Educational Resources Information Center

    LaPointe, Leonard L.; Heald, Gary R.; Stierwalt, Julie A. G.; Kemker, Brett E.; Maurice, Trisha

    2007-01-01

    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…

  12. Neuronal Effects of Auditory Distraction on Visual Attention

    ERIC Educational Resources Information Center

    Smucny, Jason; Rojas, Donald C.; Eichman, Lindsay C.; Tregellas, Jason R.

    2013-01-01

    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…

  13. Independence of Performance and Self-Report Measures of Distractibility.

    ERIC Educational Resources Information Center

    Paulhus, Delroy L.; And Others

    1990-01-01

    Describes a study using self-report measures of students' responses to auditory and visual stimuli to measure distractibility in task performance among 224 Canadian undergraduates. Findings show the absence of any link between self-reported distractibility and actual performance. Study shows correlations between personality type and…

  14. Implementation Intentions and Test Anxiety: Shielding Academic Performance from Distraction

    ERIC Educational Resources Information Center

    Parks-Stamm, Elizabeth J.; Gollwitzer, Peter M.; Oettingen, Gabriele

    2010-01-01

    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.,…

  15. Interference by Process, Not Content, Determines Semantic Auditory Distraction

    ERIC Educational Resources Information Center

    Marsh, John E.; Hughes, Robert W.; Jones, Dylan M.

    2009-01-01

    Distraction by irrelevant background sound of visually-based cognitive tasks illustrates the vulnerability of attentional selectivity across modalities. Four experiments centred on auditory distraction during tests of memory for visually-presented semantic information. Meaningful irrelevant speech disrupted the free recall of semantic…

  16. 77 FR 15398 - Attentive Driving: Countermeasures for Distraction Forum

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-15

    ... SAFETY BOARD Attentive Driving: Countermeasures for Distraction Forum The National Transportation Safety Board (NTSB) will convene a forum, Attentive Driving: Countermeasures for Distraction, which will begin... the forum, and all five NTSB Board Members will serve as members of the Board of Inquiry. The forum...

  17. Conservative management of a large maxillary cyst.

    PubMed

    Rees, J S

    1997-01-01

    This article describes the treatment of a large maxillary cyst by root canal treatment and decompression using a hollow drain made from surgical suction tubing. The rationale behind the use of this technique is reviewed and its advantages highlighted. PMID:9477796

  18. Revisiting the Factors Underlying Maxillary Midline Diastema

    PubMed Central

    Jaija, Abdullah M. Zakria; El-Beialy, Amr Ragab; Mostafa, Yehya A.

    2016-01-01

    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

  19. Revisiting the Factors Underlying Maxillary Midline Diastema.

    PubMed

    Jaija, Abdullah M Zakria; El-Beialy, Amr Ragab; Mostafa, Yehya A

    2016-01-01

    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

  20. Metronomic palliative chemotherapy in maxillary sinus tumor

    PubMed Central

    Patil, Vijay M.; Noronh, Vanita; Joshi, Amit; Karpe, Ashay; Talreja, Vikas; Chandrasekharan, Arun; Dhumal, Sachin; Prabhash, Kumar

    2016-01-01

    Background: Metronomic chemotherapy consisting of methotrexate and celecoxib recently has shown promising results in multiple studies in head and neck cancers. However, these studies have not included patients with maxillary sinus primaries. Hence, the role of palliative metronomic chemotherapy in patients with maxillary sinus carcinoma that is not amenable to radical therapy is unknown. Methods: This was a retrospective analysis of carcinoma maxillary sinus patients who received palliative metronomic chemotherapy between August 2011 and August 2014. The demographic details, symptomatology, previous treatment details, indication for palliative chemotherapy, response to therapy, and overall survival (OS) details were extracted. SPSS version 16 was used for analysis. Descriptive statistics have been performed. Survival analysis was done by Kaplan–Meier method. Results: Five patients had received metronomic chemotherapy. The median age was 60 years (range 37–64 years). The proportion of patients surviving at 6 months, 12 months, and 18 months were 40%, 40%, and 20%, respectively. The estimated median OS was 126 days (95% confidence interval 0–299.9 days). The estimated median survival in patients with an event-free period after the last therapy of <6 months was 45 days, whereas it was 409 days in patients with an event-free period postlast therapy above 6 months (P = 0.063). Conclusion: Metronomic chemotherapy in carcinoma maxillary sinus holds promise. It has activity similar to that seen in head and neck cancers and needs to be evaluated further in a larger cohort of patients.

  1. Finite element analysis of rapid canine retraction through reducing resistance and distraction

    PubMed Central

    XUE, Junjie; YE, Niansong; YANG, Xin; WANG, Sheng; WANG, Jing; WANG, Yan; LI, Jingyu; MI, Congbo; LAI, Wenli

    2014-01-01

    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

  2. Cordycepin prevents oxidative stress-induced inhibition of osteogenesis

    PubMed Central

    Wang, Feng; Yin, Peipei; Lu, Ye; Zhou, Zubin; Jiang, Chaolai; Liu, Yingjie; Yu, Xiaowei

    2015-01-01

    Oxidative stress is known to be involved in impairment of osteogenesis and age-related osteoporosis. Cordycepin is one of the major bioactive components of Cordyceps militaris that has been shown to exert antioxidant and anti-inflammatory activities. However, there are few reports available regarding the effects of cordycepin on osteogenesis and the underlying mechanism. In this study, we investigated the potential osteoprotective effects of cordycepin and its mechanism systematically using both in vitro model as well as in vivo mouse models. We discovered that hydrogen peroxide (H2O2) induced inhibition of osteogenesis which was rescued by cordycepin treatment in human bone marrow mesenchymal stem cells (BM-MSCs). Cordycepin exerted its protective effects partially by increasing or decreasing expression of osteogenic and osteoclastogenesis marker genes. Treatment with cordycepin increased Wnt-related genes' expression whereas supplementation of Wnt pathway inhibitor reversed its protective effects. In addition, administration of cordycepin promoted osteogenic differentiation of BM-MSCs by reducing oxidative stress in both ovariectomized and aged animal models. Taken together, these results support the protective effects of cordycepin on oxidative stress induced inhibition of osteogenesis by activation of Wnt pathway. PMID:26462178

  3. Cordycepin prevents oxidative stress-induced inhibition of osteogenesis.

    PubMed

    Wang, Feng; Yin, Peipei; Lu, Ye; Zhou, Zubin; Jiang, Chaolai; Liu, Yingjie; Yu, Xiaowei

    2015-11-01

    Oxidative stress is known to be involved in impairment of osteogenesis and age-related osteoporosis. Cordycepin is one of the major bioactive components of Cordyceps militaris that has been shown to exert antioxidant and anti-inflammatory activities. However, there are few reports available regarding the effects of cordycepin on osteogenesis and the underlying mechanism. In this study, we investigated the potential osteoprotective effects of cordycepin and its mechanism systematically using both in vitro model as well as in vivo mouse models. We discovered that hydrogen peroxide (H2O2)-induced inhibition of osteogenesis which was rescued by cordycepin treatment in human bone marrow mesenchymal stem cells (BM-MSCs). Cordycepin exerted its protective effects partially by increasing or decreasing expression of osteogenic and osteoclastogenesis marker genes. Treatment with cordycepin increased Wnt-related genes' expression whereas supplementation of Wnt pathway inhibitor reversed its protective effects. In addition, administration of cordycepin promoted osteogenic differentiation of BM-MSCs by reducing oxidative stress in both ovariectomized and aged animal models. Taken together, these results support the protective effects of cordycepin on oxidative stress induced inhibition of osteogenesis by activation of Wnt pathway. PMID:26462178

  4. Memory as discrimination: what distraction reveals.

    PubMed

    Beaman, C Philip; Hanczakowski, Maciej; Hodgetts, Helen M; Marsh, John E; Jones, Dylan M

    2013-11-01

    Recalling information involves the process of discriminating between relevant and irrelevant information stored in memory. Not infrequently, the relevant information needs to be selected from among a series of related possibilities. This is likely to be particularly problematic when the irrelevant possibilities not only are temporally or contextually appropriate, but also overlap semantically with the target or targets. Here, we investigate the extent to which purely perceptual features that discriminate between irrelevant and target material can be used to overcome the negative impact of contextual and semantic relatedness. Adopting a distraction paradigm, it is demonstrated that when distractors are interleaved with targets presented either visually (Experiment 1) or auditorily (Experiment 2), a within-modality semantic distraction effect occurs; semantically related distractors impact upon recall more than do unrelated distractors. In the semantically related condition, the number of intrusions in recall is reduced, while the number of correctly recalled targets is simultaneously increased by the presence of perceptual cues to relevance (color features in Experiment 1 or speaker's gender in Experiment 2). However, as is demonstrated in Experiment 3, even presenting semantically related distractors in a language and a sensory modality (spoken Welsh) distinct from that of the targets (visual English) is insufficient to eliminate false recalls completely or to restore correct recall to levels seen with unrelated distractors . Together, the study shows how semantic and nonsemantic discriminability shape patterns of both erroneous and correct recall. PMID:23661190

  5. Disposed to distraction: genetic variation in the cholinergic system influences distractibility but not time-on-task effects.

    PubMed

    Berry, Anne S; Demeter, Elise; Sabhapathy, Surya; English, Brett A; Blakely, Randy D; Sarter, Martin; Lustig, Cindy

    2014-09-01

    Both the passage of time and external distraction make it difficult to keep attention on the task at hand. We tested the hypothesis that time-on-task and external distraction pose independent challenges to attention and that the brain's cholinergic system selectively modulates our ability to resist distraction. Participants with a polymorphism limiting cholinergic capacity (Ile89Val variant [rs1013940] of the choline transporter gene SLC5A7) and matched controls completed self-report measures of attention and a laboratory task that measured decrements in sustained attention with and without distraction. We found evidence that distraction and time-on-task effects are independent and that the cholinergic system is strongly linked to greater vulnerability to distraction. Ile89Val participants reported more distraction during everyday life than controls, and their task performance was more severely impacted by the presence of an ecologically valid video distractor (similar to a television playing in the background). These results are the first to demonstrate a specific impairment in cognitive control associated with the Ile89Val polymorphism and add to behavioral and cognitive neuroscience studies indicating the cholinergic system's critical role in overcoming distraction. PMID:24666128

  6. Behavioral Distraction by Auditory Novelty Is Not Only about Novelty: The Role of the Distracter's Informational Value

    ERIC Educational Resources Information Center

    Parmentier, Fabrice B. R.; Elsley, Jane V.; Ljungberg, Jessica K.

    2010-01-01

    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…

  7. A Guide to Education for Children with Osteogenesis Imperfecta. What Is OIF? Care of an Osteogenesis Imperfecta Baby and Child.

    ERIC Educational Resources Information Center

    Ostegenesis Imperfecta Foundation, Inc., Manchester, NH.

    Three pamphlets provide basic information on the care and education of children with osteogenesis imperfecta (OI) a lifelong liability to fractures due to imperfectly formed "brittle bones." The first brochure, a guide to education for children with OI, addresses the importance of attitudes, the value of early education, public school enrollment,…

  8. The costs of distraction: The effect of distraction during repeated picture processing on the LPP.

    PubMed

    Paul, Sandra; Kathmann, Norbert; Riesel, Anja

    2016-05-01

    Confrontation with anxiety-provoking situations is an effective treatment for anxiety disorders. However, underlying processes of the effects of exposure and its prevention by avoidance are barely understood. We investigated consequences of repeatedly withdrawing attention from or maintaining it to unpleasant images using ERPs. Thirty-five healthy participants were presented with neutral and unpleasant images in two experimental phases. During habituation phase, participants should attend to or distract themselves from pictures. The same picture-instruction combinations were presented three times. In the re-exposure phase, all pictures were presented again with the attend instruction. In the habituation phase, repeated presentation reduced sustained attention as reflected in decreased late positive potential (LPP) amplitudes when participants attended to pictures. This habituation effect was absent during distraction. In the re-exposure phase, increased LPP amplitudes were found for pictures with a distraction history. This highlights the role of avoidance in the development and maintenance of exaggerated attention to threatening stimuli. PMID:27064106

  9. Active and passive distraction in children undergoing wound dressings.

    PubMed

    Nilsson, Stefan; Enskär, Karin; Hallqvist, Carina; Kokinsky, Eva

    2013-04-01

    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. PMID:22819747

  10. Electronic media use, reading, and academic distractibility in college youth.

    PubMed

    Levine, Laura E; Waite, Bradley M; Bowman, Laura L

    2007-08-01

    Activities that require focused attention, such as reading, are declining among American youth, while activities that depend on multitasking, such as instant messaging (IMing), are increasing. We hypothesized that more time spent IMing would relate to greater difficulty in concentrating on less externally stimulating tasks (e.g., academic reading). As hypothesized, the amount of time that young people spent IMing was significantly related to higher ratings of distractibility for academic tasks, while amount of time spent reading books was negatively related to distractibility. The distracting nature and the context of IMing in this population are described. PMID:17711365