Comparison of Different Fixation Types Used in Unilateral Mandibular Condylar Fractures: An In Vivo Study With New Biomechanical Model

Onder, M Ercument/0000-0002-1488-616XWOS: 000379793500073PubMed: 27315307Introduction: The aim of this in vivo study is to compare the single-titanium, double-titanium mini plate, and single resorbable plate systems used in internal rigid fixation of the unilateral mandibular condylar fractures on new design biomechanical model. Methods: Thirty synthetic polyurethane models were used for biomechanical testing. Fracture lines were created for each model. Fragments were fixed with single-titanium plates in Group A (n = 10), double-titanium plates in Group B (n = 10), and single biodegradable plate (PPLA) in Group C (n = 10). Masticatory forces were applied to the models and the biomechanical properties of the titanium plate and screws, resorbable plate, and screws were evaluated. Results: The average failure force for Group A, Group B, and Group C is 199, 324, 177N and the average bone displacement for Group A, Group B, Group C is 1.9, 0.3, 2.1 mm, respectively. Discussion: Double titanium plates showed the most acceptable results in the fixation of unilateral subcondylar fractures where the single titanium and biodegradable plate systems failed to provide enough stability in unilateral subcondylar fracture fixation. Biodegradable plate systems are still not an alternative in fixation of unilateral condylar fractures

Autogenous abdominal fat transplantation into temporomandibular joint following removal of osteochondroma

Background: An osteochondroma (OC) of the condylar process is a rare condition which primarily affects the mandibular condyle. There are several surgical treatment protocols of OC. As effective hemostatic agents and space fillers, autogenous free-fat grafts prevent scar formation and helps to hinder the accumulation of blood and serum, which otherwise, may be replaced by a dense collagen (scar), osteoid or bone. We report the autogenous abdominal fat transplantation, following the removal of a condylar OC. Methods: A 42-year-old man presented with the one-year history of progressive facial asymmetry and deviation of the chin, cross-bite to the contralateral side, and difficulty in mastication. Radiographic and clinical findings confirmed the diagnosis of an OC. Computed tomography (CT) showed lateral and inferior displacement of the right mandibular condyle due to the presence of a bone lesion from the medial aspect of the condylar head. Results: The OC was removed; the remaining portion of the condyle was re-shaped and smoothened. Abdominal fat harvesting was done 2–3 cm below the umbilicus and 3–5 cm length on the transverse midline. The defective area was filled with a harvested autogenous abdominal fat. Conclusion: Our results suggest that autogenous abdominal fat graft placement after the removal of OC with condyloplasty is yielded satisfactory treatment outcomes. Keywords: Autogenous abdominal fat, Osteochondroma, TM

Stress Analysis of Zygomatic Implants on the Augmented Maxillary Sinus: Is It Necessary to Graft?

Onder, M Ercument/0000-0002-1488-616X; ATIL, Fethi/0000-0002-8286-4819WOS: 000417037500009PubMed: 28719569Purpose: Zygomatic implants are becoming an ideal therapy with advanced implant-supported prosthetic treatment for the posterior atrophic maxilla. The purpose of this study is to examine the quantity and distribution of stress, which was caused by zygomatic implants placed using intrasinus method with or without augmentation to the atrophic posterior maxilla. Materials & Methods: In this study, 3-dimensional atrophic edentulous maxilla models with and without sinus augmentation are designed with computer-aided programs. Stress analysis was carried out on the created computer models for maxillary alveolar cortical bone, for cortical bone in the zygomaticomaxillary suture, and for zygomatic spongy bone at the apex of the zygomatic implant and for metal substructure of Von Misses stress data. Results: Having augmented the maxillary sinus with graft, it was observed that after the loading especially in the posterior region, the tensile and compressive stresses on the alveolar crest was distributed more homogeneously and the stress generated on the cortical bone was reduced through the graft. Conclusion: Although zygomatic implants are graftless solutions for athrophic maxilla, sinus augmentation will be useful for bearing stress around the implants.Kirikkale University BAP unit [2013-11]The authors claim to have no financial interest, either directly or indirectly, in the products or information listed in the article. The authors declare no conflict of interest. All authors have viewed and agreed to the submission. This research was funded by the Kirikkale University BAP unit with the number (2013-11). The funders had no role in the preparation of the manuscript

Effects of Local Low-Dose Alendronate Injections Into the Distraction Gap on New Bone Formation and Distraction Rate on Distraction Osteogenesis

Onder, M Ercument/0000-0002-1488-616X; ATIL, Fethi/0000-0002-8286-4819WOS: 000415085100107PubMed: 29095728Bisphosphonates that constrain bone resorption have a direct effect on osteoclast function. In this experimental study, the effects of low-dose local alendronate injections on the distraction gap (DG) in rabbit mandible at 2 different rates were evaluated. The experimental study was conducted on 20 male, New Zealand white rabbits. The animals were divided into 3 experimental groups and 1 control group. Group 1 consisted of animals with distraction at the rate of 1 mm/day, receiving postoperative local low-dose alendronate local injections into the DG. Group 2 consisted of animals with distraction at the rate of 2 mm/day, receiving postoperative 0.75 mu g/kg of alendronate local injections into the DG. Group 3 consisted of animals with distraction at the rate of 2 mm/day, receiving postoperative 0.2 mL local saline injections into the DG. Group 4 consisted of animals with distraction at the rate of 1 mm/day, receiving postoperative 0.2 mL local saline injections into the DG. All the injections were performed immediately postoperatively and for all groups at 1, 2, 3, and 4 weeks following surgery. The distraction zones were evaluated using dual-energy X-ray absorptiometry and histological analysis. Histologically, bone healing was found to be significantly accelerated in Groups 1 and 4 compared with Groups 2 and 3 (P<0.05). Bone healing was superior in Group 1 and the difference was statistically significant compared with Group 4. There was a significant increase in mean bone mineral density in the 1 mm daily rate groups (Groups 1 and 4) compared with the 2 mm daily rate groups (Groups 2 and 3) (P<0.05). Local low-dose alendronate injections could be an effective way for improving bone formation in distraction osteogenesis. Furthermore, the results of this study did not support the hypothesis that injections of local low-dose alendronate may allow 2 mm/day instead of 1 mm/day of elongation in the rabbit mandible.Kirikkale University Scientific Research Project Department [2011-66]This study is supported by Kirikkale University Scientific Research Project Department. Project No: 2011-66

Stress Analysis of Prostheses Retained with Zygomatic Implants on Augmented and Non-Augmented Maxillary Sinus

Onder, M Ercument/0000-0002-1488-616XWOS:000549448200007Zygomatic implants for toothless, atrophic posterior maxilla are effective treatment options and it is known that graft use has a positive effect on the zygomatic implant stability with this treatment option. The aim of this study was to evaluate the stress values and their distribution at zygomatic implant-supported prosthetic infrastructure in augmented and non-augmented models. In this study, the three-dimensional finite element method was used and 2 zygomatic implants (47.5 x 4.0 mm), 2 conventional implants (13 x 3.75 mm) and atrophic maxilla with augmented and non-augmented maxillary sinus with prosthetic infrastructure, were modelled. A vertical load of 150 N was applied onto the maxillary model at 4 different regions (#9, #12, #14 and #15). The von Mises stress, which is produced as a result of loading of zygomatic implants and prosthetic infrastructure has been evaluated in augmented and non-augmented models. The highest von Mises stress value for the prosthetic infrastructure was determined in the non-augmented model as a result of the loading to region #9 (MPa 222,886). Consequently, grafting procedures will increase bone support and reduce stresses in the prosthetic substructure, especially in posterior loads in the maxilla with low bone density

Push and Pull Factors of Why Medical Students Want to Leave Türkiye: A Countrywide Multicenter Study

Phenomenon: Physician immigration from other countries is increasing as developed countries continue to be desirable destinations for physicians; however, the determinants of Turkish physicians’ migration decisions are still unclear. Despite its wide coverage in the media and among physicians in Türkiye, and being the subject of much debate, there is insufficient data to justify this attention. With this study, we aimed to investigate the tendency of senior medical students in Türkiye to pursue their professional careers abroad and its related factors. Approach: This cross-sectional study involved 9881 senior medical students from 39 different medical schools in Türkiye in 2022. Besides participants’ migration decision, we evaluated the push and pull factors related to working, social environment and lifestyle in Türkiye and abroad, medical school education inadequacy, and personal insufficiencies, as well as the socioeconomic variables that may affect the decision to migrate abroad. The analyses were carried out with a participation rate of at least 50%. Findings: Of the medical students, 70.7% had emigration intentions. Approximately 60% of those want to stay abroad permanently, and 61.5% of them took initiatives such as learning a foreign language abroad (54.5%) and taking relevant exams (18.9%). Those who wanted to work in the field of Research & Development were 1.37 (95% CI: 1.22–1.54) times more likely to emigrate. The push factor that was related to emigration intention was the “working conditions in the country” (OR: 1.89, 95% CI: 1.56–2.28) whereas the “social environment/lifestyle abroad” was the mere pull factor for the tendency of emigration (OR: 1.73, 95% CI: 1.45–2.06). In addition, the quality problem in medical schools also had a significant impact on students’ decisions (OR: 2.20, 95% CI: 1.83–2.65). Insights: Although the percentage of those who want to emigrate “definitely” was at the same level as in the other developing countries, the tendency to migrate “permanently” was higher in Türkiye. Improving working conditions in the country and increasing the quality of medical faculties seem vital in preventing the migration of physicians