Treatment for Adult Mandibular Condylar Process Fractures: A Network Meta-Analysis of Randomized Clinical Trials.

PURPOSE: Using network meta-analyses (NMA) has become increasingly valuable as it enables the comparison of interventions that have not been directly compared in a clinical trial. To date, there has not been a NMA of randomized clinical trials (RCT) that compares all types of treatments for mandibular condylar process fractures (MCPFs). The aim of this NMA was to compare and rank all the available methods used in the treatment of MCPFs. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search was conducted in 3 major databases up to January 2023 to retrieve RCTs that compared various closed and open treatment methods for MCPFs. The predictor variable is treatment techniques: arch bars (ABs) + wire maxillomandibular fixation (MMF), rigid MMF with intermaxillary fixation screws, AB + functional therapy with elastic guidance (AB functional treatment), AB rigid MMF/functional treatment, single miniplate, double miniplate, lambda miniplate, rhomboid plate, and trapezoidal miniplate. Postoperative complications were the outcome variables and included occlusion, mobility, and pain, among other things. Risk ratio (RR) and standardized mean difference were calculated. Version 2 of the Cochrane risk-of-bias tool and Grading of Recommendations, Assessment, Development, and Evaluations system were used to determine the certainty of the results. RESULTS: The NMA included a total of 10,259 patients from 29 RCTs. At ≤6 months, the NMA revealed that the use of 2-miniplates significantly reduced malocclusion compared to rigid MMF (RR = 2.93; confidence interval [CI]: 1.79 to 4.81; very low quality) and functional treatment (RR = 2.36; CI: 1.07 to 5.23; low quality).Further, at ≥6 months, 2-miniplates resulted in significantly lower malocclusion compared to rigid MMF with functional treatment (RR = 3.67; CI: 1.93 to 6.99; very low quality).Trapezoidal plate and AB functional treatment were ranked as the best options in 3-dimensional (3D) plates and closed groups, respectively.3D-miniplates (very low-quality evidence) were ranked as the most effective treatment for reducing postoperative malocclusion and improving mandibular functions after MCPFs, followed closely by double miniplates (moderate quality evidence). CONCLUSIONS: This NMA found no substantial difference in functional outcomes between using 2-miniplates versus 3D-miniplates to treat MCPFs (low evidence).However, 2-miniplates led to better outcomes than closed treatment (moderate evidence).Additionally, 3D-miniplates produced better outcomes for lateral excursions, protrusive movements, and occlusion than closed treatment at ≤6 months (very low evidence).

Most Facial Fractures Do Not Require Surgical Intervention.

PURPOSE: Literature describing the number of patients that had a facial fracture that required surgical intervention in the United States is very limited. The purpose of this study was to evaluate the percentage of patients who required surgical intervention after presenting to a Level 1 Trauma Center with 1 or more facial fractures. MATERIALS AND METHODS: This was a retrospective cross-sectional study of all patients who presented with facial fracture(s) to University Hospital, a Level 1 Trauma Center (San Antonio, Texas), over a 5-year period from July 2015 to July 2020. Patients' charts that had 1 or more International Classification of Diseases 10 codes pertaining to facial fractures were collected. Cases were subdivided by fracture location: mandible, midface, upper face, or a combination of any of the aforementioned locations (predictor variables). After subdividing based on location, each chart was then reviewed and separated based on whether or not surgical intervention was provided (primary outcome variable). Data were tabulated and analyzed with descriptive and inferential statistics. RESULTS: Over the 5-year period, 3,416 patients presented with facial fractures. Of the 3,126 patients who survived their injuries and were not lost to follow-up, the vast majority (80.9%) did not require surgical intervention for their facial fractures. Mandible fractures required surgical intervention, whether isolated or in combination, much more frequently than in patients who did not have any type of mandible fracture (RR 8.01, 95% CI 6.92-9.27, P < .05 and RR 4.60, 95% CI 3.42-6.18, P < .05, respectively). Patients aged 50 years or less were also more likely to receive surgical intervention than those aged 51 years and more (RR 1.98 95% CI 1.63-2.41, P < .05). CONCLUSIONS: The vast majority of facial fractures that present to a Level 1 Trauma Center do not require surgical intervention. Patients who present with any type of mandible fracture and are aged 50 years or less are more likely to need surgical intervention.

Comparison of the Accuracy of Maxillary Positioning With Interim Splints Versus Patient-Specific Guides and Plates in Executing a Virtual Bimaxillary Surgical Plan.

PURPOSE: An extension of digital technology is to provide patient-specific hardware to reposition the first jaw in a bimaxillary case without the use of an intermediate splint. The purpose of our study was to determine if there were significant differences in maxillary repositioning using interim splints versus patient-specific guides and implants (PSIs) in executing a bimaxillary virtual surgical plan (VSP). MATERIALS AND METHODS: This is a retrospective cohort study of patients who underwent bimaxillary orthognathic surgery with interim splints or PSIs planned with VSP at our institution. The difference in maxillary positions from the VSP to the postoperative cone-beam computed tomography (CBCT) was evaluated in both groups. The primary predictor variable was the method by which the maxilla was repositioned (interim splint vs PSI). The primary outcome variable was the postoperative 3D position of the maxillary incisors and right and left first molars in the anteroposterior, transverse, and vertical dimensions. Differences in the planned and postoperative positions of the above landmarks in all three planes of space between the two groups were statistically analyzed. RESULTS: A total of 82 patients were included. 13 patients had their maxillae repositioned with an interim splint between the unoperated mandible and the mobile maxilla, and 69 patients had their maxilla repositioned using custom drill/cutting guides and a PSI. The mean difference between the planned and actual position of the maxilla in the PSI group was smaller than in the splint group. In the PSI group alone, vertical changes were accurate whether the maxilla was being superiorly or inferiorly repositioned. CONCLUSION: The use of a PSI provides more accurate maxillary repositioning during bimaxillary surgery than the use of an interim splint.

Treatment of Frontal Sinus Fractures: A Systematic Review and Meta-analysis.

PURPOSE: There is still no consensus about the best treatment for frontal sinus fractures (FSFs). Thus, the aims of this study were to answer the following questions: 1) what treatment of FSFs has the lowest rate of postoperative complications? 2) does sinus preservation using observation produce a lower complication rate? 3) are FSFs with nasofrontal outflow tract (NFOT) injury associated with greater complication rates following different treatment options when compared to those patients without NFOT involvement? METHODS: A systematic review and meta-analysis were performed based on PRISMA that included several databases with specific keywords, a reference search, and a manual search for suitable articles. Randomized clinical trials, controlled clinical studies, retrospective studies and case series that estimated complications rate after different treatments options for FSFs were included. The predictor variable was treatment groups, including observation, ORIF, cranialization and obliteration. The outcome variable was complication rate and correlation between complication rate and presence/absence of NFOT. A weighted complication rate/proportion using a random effect model, or risk ratio (RR) with a 95% confidence interval (CI), was performed to construct forest plots. Data analysis was done using a comprehensive meta-analysis. RESULTS: A total of 2,911 patients with FSFs enrolled in 23 studies were included in this study. The weighted complication rate for different treatment was as follows: observation (7%), ORIF (9.4%), obliteration (10.6%), and cranialization (11%). Nonsurgical treatment decreased the complication rate by 2.1 times (low quality evidence, RR = 2.1, CI: 1.13 to 3.9, P = .000) when compared to surgical treatments for FSFs. CR for fractures with NFOT was 8 % (55/619) compared to a complication rate of 5% (18/353) for fractures without NFOT with insignificant difference (very low quality evidence, RR = 1.7, CI: 0.75 to 4.1, P = .158). CONCLUSIONS: FSFs vary in their severity and treatments. The more severe fractures, the higher the complication rate, no matter how they were treated.

Complications of Mandibular Fracture Repair and Secondary Reconstruction.

Mandibular fractures are common facial injuries. Their treatment varies as do postoperative complications. This paper discusses the common complications that are associated with the treatment of mandibular fractures and presents management strategies.

Combination of Rigid and Nonrigid Fixation Versus Nonrigid Fixation for Bilateral Mandibular Fractures: A Multicenter Randomized Controlled Trial.

PURPOSE: We aimed to compare complication rates and functional outcomes in patients with bilateral mandibular fractures treated with different degrees of internal fixation rigidity. PATIENTS AND METHODS: This international, multicenter randomized controlled trial included adults with bilateral mandibular fractures located at either the angle and body, angle and symphysis, or body and symphysis. Patients were treated with either a combination of rigid fixation for the anterior fracture and nonrigid fixation for the posterior fracture (mixed fixation) or nonrigid fixation for both fractures. The primary outcome was complications within 6 weeks after surgery. Secondary outcomes were complications within 3 months, Helkimo dysfunction index, and mandibular mobility at 6 weeks and 3 months after surgery. RESULTS: Of the 315 patients enrolled, 158 were randomized to the mixed fixation group and 157 to the nonrigid fixation group. The overall complication rate at 6 weeks in the intention-to-treat population was 9.6% (95% confidence interval [CI], 5.3% to 15.6%) in the mixed fixation group and 7.8% (95% CI, 4.0% to 13.5%) in the nonrigid fixation group. With an unadjusted odds ratio of 1.25 (95% CI, 0.51 to 3.17), there were no statistically significant differences in complication rates between the 2 groups (P = .591). A multivariable model for complication risk at 6 weeks found no significant differences between treatment groups, but patients with moderate or severe displacement had a higher complication rate than those with no or minimal displacement (adjusted odds ratio, 4.58; 95% CI, 1.16 to 18.06; P = .030). There were no significant between-group differences in complication rates at 3 months. Moreover, no significant differences in Helkimo dysfunction index and mandibular mobility index at 6 weeks and 3 months were found between groups according to treatment allocated and treatment received. CONCLUSIONS: A combination of rigid and nonrigid fixation in patients with bilateral mandibular fracture has similar complication rates and functional outcomes to nonrigid fixation for both fractures.

Barriers to Full Text Journal Publication of Abstracts Presented at Annual AAOMS Meetings.

PURPOSE: The purpose of the present study was to identify the perceived barriers to full-text journal publication (JP) from abstracts presented at the 2010-2013 American Association of Oral and Maxillofacial Surgeons (AAOMS) meetings. METHODS AND MATERIALS: In the present cross-sectional study, all unpublished AAOMS abstracts (n = 473) from the temporal period were procured using a database from a previous publication. An online questionnaire was then distributed to the primary or secondary author for whom an e-mail address was available through the AAOMS Member Directory (n = 260) to assess 1) the current publication status of the abstract; and 2) the perceived barriers to JP. The responses were summarized with descriptive statistics. RESULTS: Of the 260 authors surveyed, 51 responded, for a response rate of 19.6%. At the time of the survey, 66.7% of the authors stated that submission for JP had not been pursued, and 15.7% stated that the abstract had achieved JP. However, no citations were provided. Overall, a low perceived priority (52.9%), insufficient time (50%), methodologic limitations (23.5%), and inadequate institutional support (17.6%) were the 4 primary reasons cited by the authors for the failure to pursue or achieve JP. CONCLUSIONS: JP of abstracts presented at the annual AAOMS meeting is very low, with many barriers to JP of presented abstracts.

The hierarchy of different treatments for arthrogenous temporomandibular disorders: A network meta-analysis of randomized clinical trials.

PURPOSE: Different treatment options for patients with arthrogenous Temporomandibular Disorders (TMDs) have been reported. However, evidence regarding the most effective intervention using network meta-analysis (NMA) has not been performed. Thus, we conducted a NMA of randomized clinical trials (RCTs) to identify the most effective treatment of arthrogenous TMDs with respect to pain reduction and improved mouth opening, and to generate a ranking according to their effectiveness. MATERIAL AND METHODS: An electronic search on three major databases was undertaken to identify RCTs published before August 2019, comparing up to fourteen different treatments against control/placebo patients for arthrogenous TMDs with respect to pain reduction and improved mouth opening. The treatment variables were controls/placebo, conservative treatment (muscle exercises and occlusal splint therapy), occlusal splint therapy alone, intraarticular injection (IAI) of hyaluronic acid (HA) or corticosteroid (CS), arthrocentesis with or without HA, CS and platelet-rich plasma (PRP), arthroscopy with or without HA and PRP, open joint surgery, and physiotherapy. Frequentist NMA was performed using STATA software. Studies meeting the inclusion criteria were divided according to the length of follow-up (short-term (≤5 months) and intermediate-term (≥6 months to 4 years) and type of TMJ arthrogenous disorders; internal derangement (ID) and TMJ osteoarthritis (OA). The standardized mean differences (SMD) in post-treatment pain reduction and maximum mouth opening (MMO) were analysed. RESULTS: Thirty-six RCTs were identified that performed comparative outcome assessments for pain and 33 RCTs for MMO. At the short term (≤5 months), IAI-HA (SMD = -2.8, CI: -3.7 to -1.8) and IAI-CS (SMD = -2.11, CI: -2.9 to -1.2) (all very low quality evidence) achieved a substantially greater pain reduction than control/placebo. At intermediate term (≥6 months), a statistically significant decrease in posttreatment pain intensity was observed following Arthroscopy-PRP (SMD = -3.5, CI: -6.2 to -0.82), Arthrocentesis-PRP (SMD = -3.08, CI: -5.44 to -0.71), Arthroscopy-HA (SMD = -3.01, CI: -5.8 to -0.12), TMJ surgery (SMD = -3, CI: -5.7 to -0.28), IAI-HA (SMD = -2.9, CI: -4.9 to -1.09) (all very low quality evidence), Arthroscopy-alone (SMD = -2.6, CI: -5.1 to -0.07, low quality evidence) and Arthrocentesis-HA (SMD = -2.3, CI: -4.5 to -018, moderate-quality evidence) when compared to the control/placebo groups. Relative to MMO, the most effective treatments for short- and intermediate-term improvement were the arthroscopy procedures (PRP > HA > alone, all very low-quality evidence) followed by Arthrocentesis-PRP (very low-quality evidence) and Arthrocentesis-HA (moderate-quality evidence). The non-invasive procedures of occlusal splint therapy, physical therapy, conservative therapy, placebo/control provided significantly lower quality outcomes relative to pain and MMO. CONCLUSION: The results of the present meta-analysis support a paradigm shift in arthrogenous TMJ disorder treatment. There is a new evidence (though on a very low to moderate quality level) that minimally invasive procedures, particularly in combination with IAI of adjuvant pharmacological agents (PRP, HA or CS), are significantly more effective than conservative treatments for both pain reduction and improvement of MMO in both short (≤5 months) and intermediate term (6 months-4 years) periods. In contrast to traditional concepts mandating exhaustion of conservative treatment options, minimally invasive procedures, therefore, deserve to be implemented as efficient first-line treatments (e.g. IAIs and/or arthrocentesis) or should be considered rather early, i.e. as soon as patients do not show a clear benefit from an initial conservative treatment.

Trends associated with debt loads among oral and maxillofacial surgery chief residents.

OBJECTIVE: This survey-based study was undertaken to investigate how total debt loads are impacting the personal and professional decisions made by graduating oral and maxillofacial surgery (OMS) residents. The aim of this study was to evaluate differences in total debt load on graduating residents and analyze the effects of this debt on career, family, and lifestyle choices after graduation. STUDY DESIGN: This study was a cross-sectional, web-based survey of all graduating OMS residents in accredited OMS residency programs in the United States. Participation in the survey was optional, and all responses were anonymously collected and the data analyzed by using Qualtrics software. The respondents were analyzed as a collective, with the predictor of the study being program training length and the outcome being total debt load, with independent analysis of select other financial variables. RESULTS: For the 246 deliverable emails, there were 120 respondents (48.7% response rate). The average graduating OMS resident was a Caucasian male (median age 32 years), living with a significant other or spouse who independently earned money, and had no dependents. The average range of accumulated debt of graduating residents was between $300,000 and $350,000, with 50.83% of the respondents having $350,000 or less in overall debt and 49.17% of the respondents having $350,000 or greater in accumulated debt. For those respondents completing 4-year programs, the average range of accumulated debt was between $250,000 and $300,000, and for those respondents completing 6-year programs, the average range of accumulated debt was between $400,000 and $450,000 (P < .08). CONCLUSIONS: Graduating OMS residents carry with them a significant amount of debt whether graduating from a 4-year program or a 6-year program. However, when subjectively queried, most of these residents stated they would again choose OMS as a career choice.

Are Office-Based Oral and Maxillofacial Surgical Procedures Profitable? A Benefit-Cost Analysis.

PURPOSE: Although many oral and maxillofacial surgical (OMS) procedures might seem to be profitable, no current data have analyzed the costs versus benefits of performing office-based OMS procedures. The purpose of the present study was to analyze the costs of performing 6 common office-based OMS procedures compared with the reimbursement rates for those same procedures. MATERIALS AND METHODS: The present study was a cross-sectional, microcosting survey analyzing the costs of materials used in the outpatient Oral-Maxillofacial Surgery clinic at the University of Texas Health Science Center at San Antonio. The costs incurred were based on dental procedure coding and national statistical databases and not on actual patient interactions. The primary predictor variable was the procedure costs for 6 commonly performed outpatient OMS procedures using 3 types of trays: a simple tray, a surgical tray, and an implant tray. The ancillary materials were listed for as-needed use for each tray. The primary outcome variable was the revenue after expenses per procedure. Descriptive statistics were computed. The net profit or net loss of performing 6 commonly performed outpatient OMS procedures was analyzed by subtracting the cost of performing the procedure from the insurance reimbursement for those procedures. RESULTS: Without the addition of sedation to the procedures, routine extractions had a net loss of $230 to $261, surgical extractions had a net loss of $153 to $242, and incision and drainage procedures had a net loss of $212 to $311. Furthermore, preprosthetic procedures had a net loss to net profit of -$269 to +$140, and pathologic procedures had a net loss to net profit of -$269 to +$326. Only implant procedures yielded a net profit of $847. CONCLUSIONS: The results of the present study have demonstrated that not all routine OMS procedures are profitable when performed alone without the inclusion of additional procedures or sedation.

The role of property rights in shaping the effectiveness of protected areas and resisting forest loss in the Yucatan Peninsula.

The impact of different types of land tenure in areas with high biodiversity and threats of deforestation remains poorly understood. We apply rigorous quasi-experimental methods and detailed geospatial data to assess the role of tenure regimes-communally held lands (specifically, ejidos), private property, and their impact on the effectiveness of protected areas, in reducing forest loss in a biodiversity hotspot- the Yucatan peninsula in Mexico. We find evidence that, while protected areas are effective on average, their impact depends on the underlying type of tenure regime and forest, proxied by biomass levels and biome. Protecting communally held land may reduce deforestation, specifically the loss of medium- and high-biomass forests, compared to forests under private property regimes. Our results have important policy implications for the conservation and climate change mitigation efforts on the Yucatan. However, the high variance in forest loss rates among ejidos indicates that other characteristics of ejidos may be central to understanding community-based forest conservation opportunities.

The effect of disc repositioning and post-operative functional splint for the treatment of anterior disc displacement in juvenile patients with Class II malocclusion.

PURPOSE: To evaluate the effect of temporomandibular joint (TMJ) disc repositioning and post-operative functional splint for the treatment of anterior disc displacement (ADD) in juvenile patients with Class II malocclusion. MATERIALS AND METHODS: Juvenile patients (≤20 years) who had bilateral TMJ ADD with and Class II malocclusion treated by disc repositioning and functional splints were included in the study. Magnetic resonance imaging (MRI) and cephalometric radiographs before surgery (T0), immediately after surgery (T1) and more than 3 months after surgery (T3) were obtained in all patients. Cephalometric values including condylar height, overjet, SNA, SNB and pogonion position etc. were measured and compared before and after disc repositioning by statistical analysis. Fourteen patients (13 female, 1 male) were included in this study. Their average age was 16.7 years (range, 12-20 years). RESULTS: Seven patients with 14 joints had an MRI at least 6 months (6-24 months, mean 14.3) prior to disc repositioning. When compared to the MRI taken just prior to surgery, of those 14 joints, 9 condyles (64.3%) had evidence of bone resorption, 5 condyles (35.7%) had new bone formation mostly at the posterior part of the condyle (21.4%). These MRIs showed the condylar height was reduced 0.81 mm ± 0.61 (P = 0.013). Pre-operative cephalometric radiographs showed increased overjet (P = 0.039). The mean post-operative follow-up was 9.4 months (range, 4-13 months). Postoperative MRI showed the condylar height increased 1.74 ± 0.98 mm after disc repositioning (P < 0.001). Newly generated bone was observed on all condyles. 84.6% of the new bone was formed on the superior and posterior-anterior surfaces. Postoperative cephalometric radiographs showed the SNB angle increased 1.83 ± 1.56°(P < 0.001), pogonion position (pg'-G') moved anteriorly 2.18 ± 3.13 mm (P = 0.028) and incisor overjet decreased 3.55 ± 1.86 mm (P < 0.001), whereas significant changes were not found in SNA, Sn - G Vert, Y-Axis, U1 SN, IMPA (L1-MP) and U1-L1 (P > 0.05). CONCLUSION: Conservative treatment for ADD with Class II malocclusion in juvenile patients may cause condyle resorption and aggravate the dentofacial deformity. Disc repositioning combined with post-operative functional splints can effectively promote condylar growth and help correct the dentofacial deformity.

Modified Temporomandibular Joint Disc Repositioning With Mini-screw Anchor: Part II-Stability Evaluation by Magnetic Resonance Imaging.

PURPOSE: The purpose of this study was to evaluate the stability of disc position and condylar status by magnetic resonance imaging (MRI) after temporomandibular joint (TMJ) disc repositioning surgery with a mini-screw anchor technique. MATERIALS AND METHODS: Patients diagnosed with anterior disc displacement (ADD) and operated on for disc repositioning from 2010 through 2016 were included in the study. MRI scans within 1 week after operation (T1) and during at least 1-year follow-up were used to evaluate changes in disc position and condylar bone. During follow-up, ADD without reduction was considered relapse and the bone status was classified as regeneration or degeneration. RESULTS: One hundred seven patients with 149 joints were included in the study. Postoperative MRI scans (T1) showed that all discs were repositioned. During an average 23.40-month follow-up (range, 12 to 84 months), 95.3% of discs (142 of 149) were still in position, whereas 4.7% of discs (7 of 149) had relapsed anteriorly. New condylar bone formation was observed in 74.50% of joints (111 of 149), no bone change was observed in 23.49% of joints (35 of 149), and bone resorption was observed in 2.01% of joints (3 of 149). CONCLUSIONS: TMJ disc repositioning by a mini-screw anchor provides stability for treatment of ADD. Disc repositioning also can stimulate condylar bone regeneration.

Scaffold-free cartilage cell sheet combined with bone-phase BMSCs-scaffold regenerate osteochondral construct in mini-pig model.

Tissue-engineered condyles provide a promising approach for end-stage osteoarthritis to reconstruct normal physiological structure and function of the temporomandibular joint (TMJ). However, lack of successful biological condyles in large animals restricts clinical translation. Scaffold-free cartilage cell sheets do not contain any polymeric material which potentially risks local nonspecific inflammatory reactions. In this study, we used cartilage cell sheets covering bone marrow mesenchymal stem cells-Polycaprolactone/Hydroxyapatite (BMSCs-PCL/HA) scaffolds (cell sheet group) transplanted subcutaneously and intramuscularly in mini-pigs. In contrast, autogenous chondrocytes were seeded on polyglycolic acid/ polylactic acid (PGA/PLA) scaffolds for 4 and 12 weeks in-vitro pre-cultivation. Then, they were used as a cartilage-phase composition covering BMSCs-PCL/HA scaffolds, then the entirety (biphase scaffold group) was transplanted subcutaneously into mini-pigs. After 12 weeks, the harvested samples were examined histologically. The cartilage layer was evaluated for thickness, glycosaminoglycan (GAG) quantitation, total collagen quantitation and Young's modulus. The biphase scaffold group failed in regeneration, while the cell sheet group regenerated biological condyle with healthy osteochondral construct. The GAG quantitation, total collagen quantitation and Young's modulus of regenerated cartilage was close to those of the natural condyle. Collectively, cartilage cell sheets combined with bone-phase composition had the potential to regenerate biological condylar.

Comparison of bone adaptation after modification in biomet standard alloplastic temporomandibular joint prostheses.

PURPOSE: The aim of the study was to compare bone adaptation after design modification in Biomet stock prostheses. MATERIALS AND METHODS: Computed tomography (CT) data of the patients treated with a Biomet TMJ replacement from 2010 to 2016 were recruited. Fossa prosthesis with a bulge and 4 types of condyle-ramus angle prostheses were virtually designed and implanted by computer-assisted simulation. The amount of bone trimming including fossa, mandibular ramus and bone graft were measured by ProPlan CMF 1.4 software. The differences between the original and modified prostheses were compared by SPSS 17.0 software for statistical analysis. RESULTS: There were 54 patients' CT data included in the study. The amount of fossa bone trimming was 150.20 mm3 in the modified prosthesis and 281.82 mm3 in the original one. The amount of ramus bone trimming was 103.86 mm3 in the modified prosthesis and 229.45 mm3 in the original one. The amount of fossa bone grafting was 95.88 mm3 in the modified prosthesis and 263.03 mm3 in the original one. There were significant differences between them (p = 0.000). CONCLUSIONS: The modified Biomet prostheses design requires less bone trimming and grafting for implantation.

Clinical and Radiologic Follow-Up of Zimmer Biomet Stock Total Temporomandibular Joint Replacement After Surgical Modifications.

PURPOSE: The aim of this study was to evaluate the clinical and radiologic results of Zimmer Biomet stock prostheses (Jacksonville, FL) in temporomandibular joint replacement after surgical modifications during at least 1 year of follow-up. PATIENTS AND METHODS: We recruited patients treated by Zimmer Biomet stock prostheses after technical modifications, including digital templates, autogenous ipsilateral bone grafting from the mandible to the fossa, salvaging of the disc remnant and suturing it to the medial aspect of the prosthesis, and fat grafts from a retromandibular incision, between 2010 and 2016. Clinical examination findings including maximal incisal opening; visual analog scale scores for pain, diet, and mandibular movement; and quality of life were compared before the operation and at least 1 year postoperatively. The status of the fossa bone graft was evaluated by computed tomography examination. RESULTS: The study comprised 38 joints in 33 patients with diagnoses including osteoarthritis, ankylosis, and neoplasm. Compared with before the operation, maximal incisal opening and visual analog scale scores for diet, function, and pain level, as well as the quality-of-life survey score, were considerably improved during the last follow-up. Computed tomography scans showed all bone grafts were completely healed within the fossa 1 year after surgery. There was no ectopic bone formation, screw loosening, or component displacement or breakage. CONCLUSIONS: Our surgical modifications of Zimmer Biomet stock prostheses showed good results for at least 1 year of follow-up.

Does encountering the facial nerve during surgical management of mandibular condylar process fractures increase the risk of facial nerve weakness? A systematic review and meta-regression analysis.

PURPOSE: The purpose of this study was to identify whether the incidence of systematically identified or incidentally encountered facial nerve branches during dissection to approach condylar fractures increases risk of transient and/or permanent facial nerve weakness. METHODS: A systematic review and meta-analysis were performed that included several databases with specific keywords, a reference search, and a manual search for suitable articles. The inclusion criteria were all clinical trials, with the aim of assessing the rate of facial nerve injuries when open reduction and internal fixation (ORIF) of condylar process fractures was performed using different surgical approaches. The articles had to have documented the number of encountered facial nerve branches during ORIF. The main outcome variable was transient and permanent facial nerve injury. The dependent variable was the event and/or number of encountered facial nerve branches during surgery, and how they were handled (i.e. dissected, retracted, etc.). RESULTS: A total of 1202 mandibular condylar fractures were enrolled in 29 studies. Rate of transient facial nerve injury (TFNI) was 11.3 % (136/1202). The number of facial nerve branches encountered intraoperatively was 543, namely buccal, marginal mandibular, zygomatic and temporal nerve branches. There was a significant correlation suggesting that there is a strong positive linear relationship between TFNI and encountered facial nerve branches (Coef = 0.1916, P = 0.001). There was no significant relationship between permanent facial nerve injury and encountered facial nerve branches (P = 0.808). TFNI was 4.3% and 18.7% for those studies expressly reporting that facial nerve branches were encountered incidentally without dissection and with dissection, respectively. For studies reporting deliberate and systematic facial nerve dissection, TFNI was 20.9%. Finally, studies that did not report any encounters of facial nerve branches, TFNI was 7.9 %. CONCLUSION: This meta-analysis demonstrated that manipulation of the facial nerve during different surgical approaches causes different incidences of facial nerve injury. The choice of surgical approach for a given fracture should take this into consideration.

Is there more to the clinical outcome in posttraumatic reconstruction of the inferior and medial orbital walls than accuracy of implant placement and implant surface contouring? A prospective multicenter study to identify predictors of clinical outcome.

PURPOSE: Reconstruction of orbital wall fractures is demanding and has improved dramatically with the implementation of new technologies. True-to-original accuracy of reconstruction has been deemed essential for good clinical outcome, and reasons for unfavorable clinical outcome have been researched extensively. However, no detailed analysis on the influence of plate position and surface contour on clinical outcome has yet been published. MATERIALS AND METHODS: Data from a previous study were used for an ad-hoc analysis to identify predictors for unfavorable outcome, defined as diplopia or differences in globe height and/or globe projection of >2 mm. Presumed predictors were implant surface contour, aberrant implant dimension or position, accuracy of reconstructed orbital volume, and anatomical fracture topography according to the current AO classification. RESULTS: Neither in univariable nor in multivariable regression models were unfavorable clinical outcomes associated with any of the presumed radiological predictors, and no association of the type of implant, i.e., standard preformed, CAD-based individualized and non-CAD-based individualized with its surface contour could be shown. CONCLUSION: These data suggest that the influence of accurate mechanical reconstruction on clinical outcomes may be less predictable than previously believed, while the role of soft-tissue-related factors may have been underestimated.