Does the Use of Botulinum Toxin in Treatment of Myofascial Pain Disorder of the Masseters and Temporalis Muscles Reduce Pain, Improve Function, or Enhance Quality of Life?

BACKGROUND: The efficacy of botulinum toxin for management of myofascial pain disorder (MPD) remains controversial. PURPOSE: The purpose was to determine if the use of onabotulinumtoxinA (onabotA) in patients with MPD reduces pain, improves function, or enhances quality of life (QoL). STUDY DESIGN, SETTING, AND SAMPLE: This is a multicenter, prospective, randomized, double-blinded, placebo-controlled clinical trial. Subjects with orofacial pain were screened for MPD as defined by the Diagnostic Criteria for Temporomandibular Disorders. PREDICTOR VARIABLE: The primary predictor variable was MPD treatment with random assignment to onabotA or placebo (saline). MAIN OUTCOME VARIABLE: The primary outcome variable was pain before treatment (T0) and at 1 month (T1) using a visual analog scale. Secondary outcome variables included pain at 2 months (T2) and 3 months (T3), maximal incisal opening (MIO), jaw function (jaw functional limitation scale), and QoL (Short Form 36) measured at T0, T1, T2, and T3. COVARIATES: Covariates included subject demographics, prior treatments, and temporomandibular joint signs/symptoms. ANALYSES: Descriptive and bivariate statistics included χ2 test, Fisher's exact test, or t-test. RESULTS: Seventy five subjects with a mean age of 37 (±11) and 35 (±12) years in the onabotA and placebo groups, respectively (P = .6). Females represented 32 (86%) and 29 (76%), respectively (P = .3). Mean visual analog scale pain score in the onabotA group was 58 (±15), 39 (±24), 38 (±23), and 38 (±20) at T0, T1, T2, and T3, respectively; and the placebo group was 54 (±14), 40 (±23), 34 (±20), and 36 (±22) at T0, T1, T2, and T3, respectively. There was no statistically significant difference in pain between groups at any time point (P = .36). There was no statistically significant difference between groups in MIO (P = .124), jaw function (P = .236), or QoL domains (P > .05) at any time point. Within-group improvement in pain was seen in both groups (P < .005). Within-group improvement in jaw function was seen in the onabotA (P = .007) and placebo (P = .005) groups. There was no within-group improvement in MIO or QoL with either group (P > .05). CONCLUSIONS: OnabotA and saline (placebo) injections both decrease pain and improve jaw function in subjects with MPD.

Does Maxillomandibular Fixation Technique Affect Occlusion Quality in Segmental LeFort I Osteotomy?

BACKGROUND: Segmental maxillary osteotomies require precise occlusal control due to variability in individual segment positioning. The role of maxillomandibular fixation (MMF) technique on occlusal control has not been validated. PURPOSE: The purpose is to measure and compare the accuracy of occlusal positioning among MMF techniques. STUDY DESIGN, SETTING, SAMPLE: This was a double-blinded in vitro study on experiment models to simulate a 3-piece LeFort I osteotomy. The models were constricted posteriorly and expanded using 3 different MMF techniques and compared to the unaltered baseline occlusion. Based on sample size calculation, 32 separate attempts were made for each MMF technique. PREDICTOR VARIABLE: The predictor variable was MMF technique (brackets, MMF screws, and embrasure wires). MAIN OUTCOME VARIABLES: The primary outcome variable was the visual occlusal analysis score, a 1.00 to 4.00 continuous scale measuring the similarity of the achieved occlusion to the planned (control) occlusion assessed by an oral and maxillofacial surgeon and an orthodontist. High visual occlusal analysis score indicated greater occlusal accuracy, with 3.50 defined as the threshold for accuracy. The secondary outcome variable was the linear error of the achieved occlusion at the canine and first molar teeth, with lower error indicating greater accuracy. An a priori accuracy threshold of 0.5 mm was set for this variable. COVARIATES: None. ANALYSES: Kruskal-Wallis test with post hoc testing was used to analyze the difference in the outcome variables of interest. P value < .05 was considered statistically significant. RESULTS: Thirty-two attempts for each technique showed that brackets had higher VAOS than MMF screws and embrasure wires (median differences 1.49 and 0.48, P < .001), and had lower linear occlusal error (median differences 0.35 to 0.99 mm, P < .001). CONCLUSION AND RELEVANCE: MMF technique influences the quality of occlusal control, with greater visual rating scores and lower linear errors seen with brackets than with embrasure wires or MMF screws.

Immediate Inferior Alveolar Nerve Reconstruction With Ablative Mandibular Resection Results in Functional Sensory Recovery.

BACKGROUND: Ablative mandibular resection with sacrifice of the inferior alveolar nerve (IAN) results in loss of sensation and decreased quality of life. PURPOSE: The purpose of this study is to evaluate functional sensory recovery (FSR) of immediate IAN allograft reconstruction performed during ablative mandibular resection at 1 year following surgery. STUDY DESIGN, SETTING, SAMPLE: This is a single-center retrospective cohort study that included consecutive subjects who underwent mandibular resection with IAN discontinuity and used a nerve allograft of ≥40 mm. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE: The primary predictor variable is the use of an immediate nerve allograft in mandibular reconstruction. MAIN OUTCOME VARIABLE(S): The main outcome variable is FSR at 1 year using the Medical Research Council Scale. COVARIATES: Covariates include subject age, sex, specific pathology, nerve gap length, and development of neuropathic pain. ANALYSES: Statistical analysis of comparison of neurosensory outcomes was measured by bivariate statistics, weighted values, repeated measures, analysis of variance, and McNemar test. RESULTS: The study sample was composed of 164 subjects, of whom 55 (33.5%) underwent nerve allograft reconstruction and 30 (18.3%) did not have nerve reconstruction. Seventy-nine subjects (48.2%) did not meet the inclusion criteria. In the entire nerve allograft group of 55 subjects, FSR was achieved in 80% at 1 year; however, in benign disease alone, 31 of 33 (94%) achieved FSR at 1 year. In the nonallograft group (all benign disease), only 2 of 30 (7%) achieved FSR at 1 year. The significant covariates were age and pathology. Benign pathologic resections were 5.2 times more likely to achieve FSR than malignancies, and all subjects ≤ 18 years of age achieved FSR. After adjusting for age, sex, pathology, nerve gap length, nerve allograft was significantly associated with achieving FSR at 1 year (adjusted odds ratio = 5.52, 95% confidence interval = (1.03, 29.51), P value = .045 < .05). CONCLUSION AND RELEVANCE: Immediate long-span IAN allograft reconstruction is effective in restoration of sensation with an overall 80% of subjects achieving FSR at 1 year, while benign disease resulted in 94% FSR at 1 year. Immediate IAN reconstruction should be considered with mandibular resection involving the IAN, especially for children and benign disease.

What Do I Do if There is No Distal Nerve Stump for Inferior Alveolar Nerve Reconstruction?

This technical note describes an innovation that addresses a clinical problem in inferior alveolar nerve (IAN) reconstruction. In some cases of mandibular resection, there is a need to resect a significant amount of the IAN along with the pathologic lesion and this may result in a lack of a distal nerve stump for completion of the neural anastomosis. This technical note offers the option to perform the distal neurorrhaphy into the residual soft tissues with the expectation that axonal sprouting will occur and result in lower lip and chin sensory reinnervation. There are no inherent risks or additional costs. The significance of this technique is that it permits IAN reconstruction in cases where the actual nerve stump is not available and improves patient care. There should be no challenges or delays to implementing this innovation for surgeons who reconstruct the IAN during ablative mandibular resection.

What Is the Linear Accuracy of Regional Voxel-Based Registration for Orthognathic Surgery Landmarks?

PURPOSE: While regional voxel-based registration (R-VBR) has been shown to have excellent reproducibility and angular accuracy, there are limited data on the linear accuracy of R-VBR for common orthognathic surgery landmarks, or on whether angular accuracy correlates with linear accuracy. The purpose of this study was to estimate the linear accuracy of R-VBR for several skeletal landmarks commonly used in orthognathic surgical planning, and to measure the correlation between angular and linear discrepancies. MATERIALS AND METHODS: This is a retrospective cross-sectional study of consecutive patients treated at a single center with nonsegmental LeFort I and bilateral sagittal split osteotomy surgery from January 2019 to November 2020. Cone beam computed tomography at the preoperative (T0) and immediate postoperative (T1) stages were analyzed to measure the postoperative positional changes of 11 orthognathic landmarks in 4 regions of interest (ROI) using R-VBR performed twice by two examiners. Pairwise correlation analysis and canonical correlation analysis were performed for the angular discrepancies (primary predictor variable) and the linear discrepancies (primary outcome variable) to measure the correlation between the two. RESULTS: In cone beam computed tomography analysis of 28 eligible subjects (16 males, 12 females; mean age 18.9 years, range 15 to 25), the mean absolute (MA) angular discrepancies ranged from 0.15° to 0.55°, while the corresponding MA linear discrepancies ranged from 0.05 to 0.41 mm. There was a strong correlation between angular and linear discrepancies that was statistically significant (P = .001 to .04, Spearman's rank correlation coefficient 0.38 to 0.87). CONCLUSIONS: For nonsegmental LeFort I osteotomies and bilateral sagittal split osteotomy, R-VBR has excellent linear accuracy within a single voxel size (0.3 mm) for commonly used orthognathic landmarks in the maxillary and distal mandibular ROI. The MA linear discrepancy for the proximal mandibular segment ROI was greater than a single voxel size, with a maximum of 0.41 mm.

Which Factors Affect the Reduction Quality of Open Reduction Internal Fixation of Mandibular Subcondylar Fractures?

BACKGROUND: Open reduction internal fixation (ORIF) of mandibular subcondylar fractures (MSF) involves several variables that could affect decision making. There is insufficient data regarding factors influencing the outcomes of MSF ORIF. PURPOSE: The purpose of this study was to investigate factors associated with quality of bony reduction of MSF and occlusion, after ORIF. STUDY DESIGN, SETTING, AND SAMPLE: We designed a retrospective cohort study of consecutively treated subjects for MSF ORIF, ages 18 to 64 years, by University of Illinois' Department of Oral and Maxillofacial Surgery, between January 1, 2013, and January 26, 2021. PREDICTOR VARIABLE: The primary predictor variable was the vertical level of MSF from the gonial angle. Secondary predictor variables included surgeon, fixation scheme (number and configuration of miniplate), surgical approach, time to surgery, mechanism of injury, vertical fragment overlap, overlying soft tissue thickness, presence of other mandibular fractures, and severity and direction of displacement. MAIN OUTCOME VARIABLES: The primary outcome variable was the mean radiographic reduction score (RRS), rated by 2 blinded observers on a 1 to 5 scale. The secondary outcome variable was presence of postoperative malocclusion as documented in the medical records. COVARIATES: Covariates were age and sex. ANALYSES: Descriptive statistics were computed. To investigate the influence of the predictor variables on reduction quality, multifactorial analysis of variance with post hoc Tukey test was performed. For malocclusion, χ2 test was performed. The level of significance was set at P < .05. RESULTS: Thirty-eight MSF in 37 subjects were included. Mean age was 32.7 years (range 18 to 64), and 83.8% were male. Mean RRS was 4.38 (standard deviation 0.77). Fixation scheme was the only variable that showed significant impact on RRS: single-straight miniplate had lower scores than double-straight (-1.50, P = .011), rhomboid (-1.29, P = .036), and ladder miniplates (-1.38, P = .048). There was 1 incidence of malocclusion (2.7%) which resolved without intervention. CONCLUSIONS AND RELEVANCE: Favorable reduction (anatomic reduction to mild discrepancies) can be achieved without malocclusion using double-straight, or rhomboid-shaped or ladder-shaped miniplates, without influences from patient or injury-related factors. In contrast, single-straight miniplate fixation resulted in moderate discrepancies in reduction, although it did not lead to malocclusion.

Novel Machine Learning Algorithms for Prediction of Treatment Decisions in Adult Patients With Class III Malocclusion.

BACKGROUND: Management of Class III (Cl III) dentoskeletal phenotype is often expert-driven. PURPOSE: The aim is to identify critical morphological features in postcircumpubertal Cl III treatment and appraise the predictive ability of innovative machine learning (ML) algorithms for adult Cl III malocclusion treatment planning. STUDY DESIGN: The Orthodontics Department at the University of Illinois Chicago undertook a retrospective cross-sectional study analyzing Cl III malocclusion cases (2003-2020) through dental records and pretreatment lateral cephalograms. PREDICTOR: Forty features were identified through a literature review and gathered from pretreatment records, serving as ML model inputs. Eight ML models were trained to predict the best treatment for adult Cl III malocclusion. OUTCOME VARIABLE: Predictive accuracy, sensitivity, and specificity of the models, along with the highest-contributing features, were evaluated for performance assessment. COVARIATES: Demographic covariates, including age, gender, race, and ethnicity, were assessed. Inclusion criteria targeted patients with cervical vertebral maturation stage 4 or above. Operative covariates such as tooth extraction and types of orthognathic surgical maneuvers were also analyzed. ANALYSES: Demographic characteristics of the camouflage and surgical study groups were described statistically. Shapiro-Wilk Normality test was employed to check data distribution. Differences in means between groups were evaluated using parametric and nonparametric independent sample tests, with statistical significance set at <0.05. RESULTS: The study involved 182 participants; 65 underwent camouflage mechanotherapy, and 117 received orthognathic surgery. No statistical differences were found in demographic characteristics between the two groups (P > .05). Extreme values of pretreatment parameters suggested a surgical approach. Artificial neural network algorithms predicted treatment approach with 91% accuracy, while the Extreme Gradient Boosting model achieved 93% accuracy after recursive feature elimination optimization. The Extreme Gradient Boosting model highlighted Wit's appraisal, anterior overjet, and Mx/Md ratio as key predictors. CONCLUSIONS: The research identified significant cephalometric differences between Cl III adults requiring orthodontic camouflage or surgery. A 93% accurate artificial intelligence model was formulated based on these insights, highlighting the potential role of artificial intelligence and ML as adjunct tools in orthodontic diagnosis and treatment planning. This may assist in minimizing clinician subjectivity in borderline cases.

Does Immediate Long-Span Nerve Allograft Reconstruction Affect the Incidence of Chronic Postsurgical and Neuropathic Pain in the Reconstructed Mandible Following Resection for Benign and Malignant Disease.

BACKGROUND: Peripheral nerve injury can lead to chronic postsurgical pain (CPSP) and neuropathic pain following major surgery. PURPOSE: Determine in patients undergoing ablative mandibular operations with transection of the trigeminal nerve: do those who undergo immediate repair, when compared to those whose nerves are not repaired, have a decreased or increased risk for CPSP or post-traumatic trigeminal neuropathic pain (PTTNp)? STUDY DESIGN, SETTING, SAMPLE: A multisite, retrospective cohort of patients who underwent resection of the mandible for benign or malignant disease with either no repair or immediate repair of the intentionally transected trigeminal nerve with a long-span nerve allograft were analyzed for the presence or absence of CPSP and PTTNp at 6 months. PREDICTOR VARIABLE: The primary predictor was the immediate repair or no repair of the trigeminal nerve. MAIN OUTCOME VARIABLE: The primary outcome was the presence or absence of CPSP and PTTNp at 6 months postsurgery. COVARIATES: There were 13 covariate variables, including age, sex, ethnicity, nerve injury, type of PTTNp, malignant or benign pathology and subtypes of each, use of radiation or chemotherapy, treatment of transected nerve end, longest follow-up time, pain scale, and onset of pain. ANALYSES: Two-tailed Student's t test and Welch's t test were performed on mean scores and post hoc logistics and linear regression modeling were performed when indicated. The confidence level for statistical significance was P value <.05. RESULTS: There were 103 and 94 subjects in the immediate and no-repair groups, respectively. The incidence of CPSP in the no-repair group was 22.3% and PTTNp was 2.12%, while there was 3.8% CPSP and 0% PTTNp in the repair group, which was statistically significant (P = <.001). Logistic regression modeling showed a statistically significant inverse relationship between the immediate repair and the incidence of CPSP/PTTNp with an odds ratio of 0.43, 95% confidence interval 0.18 to 1.01, P = .05. Greater age, malignant pathology, and chemo/radiation treatments were covariates found more frequently in the no repair group. CONCLUSION AND RELEVANCE: Immediate repair of an intentionally transected trigeminal nerve with a long-span nerve allograft during resection of the mandible for both benign and malignant disease appears to reduce CPSP and possibly eliminate the development of PTTNp.

Predictability of single versus double-barrel vascularized fibula flaps and dental implants in mandibular reconstructions: A systematic review and meta-analysis of prospective studies.

STATEMENT OF PROBLEM: Patients with vascularized bone flaps from the fibula have reduced bone height, in which case a higher prosthetic abutment is needed for their implant-supported prosthesis. Although the double-flap technique seems promising, systematic reviews and meta-analyses of prospective studies are lacking. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the grafted areas of single barrel fibular flaps (SBFF) and double-barrel fibular flaps (DBFF) by considering failure rates, dental implant complications, and bone union at the osteotomy sites. MATERIAL AND METHODS: A systematic review and meta-analysis was performed in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement, population, intervention, control, and outcomes (PICO) question, and the National Health and Medical Research Council scales. The event rate of complications and failures was calculated with a confidence interval (CI) of 95%. RESULTS: A total of 13 prospective studies with 441 participants and 330 graft sites were identified. A total of 235 participants had SBFF with 445 implants, and 95 had DBFF with 164 implants. The overall combined graft failure rates were 4.2% for SBFF and 3.2% for DBFF. The complication rate was 10% for SBFF and 1.9% for DBFF. Implant failure was at 4.7% in the SBFF group and 3.4% in the DBFF group. CONCLUSIONS: Complication rates and implant failures were similar for SBFF and DBFF. Therefore, for long-term oral rehabilitation, both SBFF and DBFF are suitable procedures for mandibular reconstruction.

What Are the Lessons Learned From the Virtual Interview Process for Oral and Maxillofacial Surgery Residency Programs Affected by COVID-19?

PURPOSE: With the outbreak of COVID-19, residency programs for the 2020 to 2021 OMS interview cycle were forced to quickly adapt to a new method of assessing candidates-virtual interviewing-for the first time. The purpose of this study is to describe applicants' perspectives regarding the advantages and disadvantages of the virtual interview process through an online descriptive survey. METHODS: This cross-sectional study utilizes a descriptive survey sent to the 2020 to 2021 interview cycle applicants of the University of Illinois at Chicago Oral and Maxillofacial Surgery (UIC OMS) residency program. The survey consisted of questions employing both scaled and open-ended designs. The questions were fabricated to extrapolate applicants' perceived advantages and disadvantages of virtual interviewing compared to their expectations of in-person interviewing by focusing on interactions, number of interviews received/attended, and overall applicant satisfaction. Descriptive statistics were computed for each variable for data analysis. RESULTS: In the 2020 to 2021 UIC OMS residency cycle, there were 288 applications. A total of 102 surveys were collected (response rate = 35.4%). Respondents attended more interviews during the virtual format due to accessibility (64.7%), and cost savings (63.7%). 42.2% of applicants felt they did not present themselves as well during the virtual interview as they would have in person and 46.1% felt they did not have a good understanding of the culture of the program after the interview. 49.0% of all participants do not feel that virtual interviews should continue in the future. CONCLUSIONS: Virtual formats would allow access to a greater number of interviews; however, they lack the ability to promote effective interaction between applicants, residents, and faculty members. The results of the study show that although applicants agreed that interviews were more accessible this year, they felt that the "personal" interaction was lacking and they could not present themselves effectively with the virtual format. Ultimately, almost half (49%) of the respondents do not wish for virtual interviews to continue in the future.

DANG (Depth-Adjusted Nerve Guide) - A Technical Note.

Traditional surgical approaches to the inferior alveolar nerve (IAN) pose a technical challenge and risk iatrogenic damage to healthy, uninvolved nerve tissue. The use of computer-assisted virtual surgical planning and fabrication of surgical guides has shown efficacy in various craniomaxillofacial surgical procedures, and may provide greater precision in accessing the inferior alveolar canal and allow for a more conservative approach. The addition of a depth control feature to a tooth-borne and bone-borne surgical guide, with the use of a standard contra-angle handpiece, provides safe and efficient access for IAN repair. This report describes this novel technique involving a guided transoral approach to the IAN for excision of a neurofibroma of the inferior alveolar nerve, with immediate peripheral nerve allograft IAN reconstruction.

Do We Need Safety Nets for Outsourced Computer-Aided Orthognathic Planning? A Two-Center Analysis.

PURPOSE: While the accuracy, cost-effectiveness, and time-efficiency of computer-aided orthognathic surgical planning (CAOP) have been studied, little is known about the influence of logistical factors of outsourced CAOP (OS-CAOP) on patient care. The purpose of this study was to investigate the limitations of OS-CAOP and their effect on treatment planning workflow and surgical outcomes. METHODS: A retrospective cross-sectional study was designed involving subjects who had undergone orthognathic surgery using CAOP from 2 academic oral and maxillofacial surgery centers in South Korea (Kyungpook National University, KNU) and the United States (University of Illinois Chicago, UIC) over an 8-year period. The primary predictor variable was use of modifications or alternatives to OS-CAOP. The primary outcome variable was the frequency of planning changes due to reasons that may have affected outcomes. Covariates included age and sex. Descriptive statistics was used, in addition to a chi-square test to analyze differences among categorical variables. RESULTS: Of a total of 642 eligible subjects in both centers, 5.8% used alternatives to OS-CAOP. 78.4% of these were due to reasons that may have affected outcomes (P < .001), representing 4.5% of all cases. The frequency of the need for OS-CAOP alternatives was identical in both centers (5.8%), but the specific reasons varied, with KNU having mostly plan-related changes (38.1% of alternatives), and UIC with more access and education-related reasons (68.8% of alternatives). At KNU, 71.4% of all alternatives were by repeat OS-CAOP, whereas at UIC, all were by in-house CAOP (IH-CAOP). CONCLUSIONS: In 2 major academic oral and maxillofacial surgery centers in South Korea and the United States, a substantial portion of OS-CAOP required pre-surgical modification, or use of alternatives. Most of the changes were for reasons that could potentially impact outcomes, prompting the need to consider establishing a "safety net" plan compatible with individual clinician's practice setting and healthcare system.

What Do We Know Beyond Reliability in Voxel-Based Registration? Validation of the Accuracy of Regional Voxel-Based Registration (R-VBR) Techniques for Orthognathic Surgery Analysis.

PURPOSE: Despite having excellent reproducibility, the accuracy of regional voxel-based registration (R-VBR) techniques used for postoperative orthognathic surgical analysis has not been validated. The purpose of this study was to validate the accuracy of R-VBR. METHODS: Preoperative (T0) and postoperative (T1) cone beam computed tomography (CBCT) of consecutive patients treated at a single center with nonsegmental LeFort I and bilateral sagittal split osteotomy were included. T1 CBCTs were oriented to match that of the standardized T0, and thus were assigned a known rotational transformation matrix in pitch/roll/yaw (P/R/Y), to create T1-prime (T1'). A copy of T1 (cT1) was made and was superimposed to T1' using R-VBR for 4 regions of interest (ROI): maxilla, distal mandible, right proximal mandible, and left proximal mandible, to create cT1'. The transformation matrix for each of the ROI was compared to those of T1' using paired t test and Bland-Altman analysis. RESULTS: Twenty-eight eligible subjects' CBCTs were analyzed. Mean difference between T1' and cT1' ranged from -0.08 to 0.14° (maximum 0.73°), with no statistically significant differences (P = 0.216 to 1). Mean absolute difference ranged from 0.13 to 0.31° (maximum 0.73°). Bland-Altman analysis showed good agreement between T1' and cT1', indicating excellent accuracy. CONCLUSIONS: R-VBR using the maxilla, distal mandible, and the bilateral proximal mandibular segments as ROI has excellent accuracy in terms of rotational measurements.

The Quality of the Evidence in Craniomaxillofacial Trauma: Are We Making Progress?

PURPOSE: The purpose of this study is to evaluate the level of evidence in the craniomaxillofacial trauma literature. The secondary purpose is to determine if improvement in the quality of evidence has been made over the past 2 decades. MATERIALS AND METHODS: This retrospective cohort study analyzed clinical articles published in select craniomaxillofacial surgery journals. Patient-focused articles were selected. The year of publication (1999, 2009, 2019) was the primary predictor variable. Secondary predictor variables included study funding status, anatomical facial region (eg maxilla, mandible, and so on), specific journal, and journal impact factor. The level of evidence was determined using the Center of Evidence-Based Medicine criteria, which served as the outcome variable. The statistical analysis included descriptive, bivariate, and regression analysis. RESULTS: The sample consisted of 469 craniomaxillofacial trauma articles, with 13.2% being published in 1999, 44.1% in 2009, and 42.6% in 2019. The majority of the studies (77.5%) were published in 4 journals. The impact factor varied among the journals with a significant improvement in the mean impact factor from (0.89 ± 0.29) in 1999 to (1.4 ± 0.47) in 2009 and a slight decline in 2019 (1.26 ± 0.71). Mandibular fractures (31.6%) and orbital trauma (26%) were the most investigated topics. Level 4 studies accounted for 67.4% of the sample, with level 3 evidence of 4.7%, level 2 of 22.6%, and level 1 of 5.3% of the included studies. Significant progress in the level of evidence has been made from 1999 but not since that time (P = .002). It is unclear why this may be but sheds light on the need for further development of high quality studies. Finally, a higher quality of evidence is associated with journal impact factor (odds ratio  = 1.9; P < .01) and funded research (odds ratio = 4.69; P = .02). CONCLUSIONS: While there has been some improvement in the level of evidence in the craniomaxillofacial trauma literature over the past 2 decades, the current quality remains low, and further progress is needed to support the practice of evidence-based medicine.

Mechanical Loading Disrupts Focal Adhesion Kinase Activation in Mandibular Fibrochondrocytes During Murine Temporomandibular Joint Osteoarthritis.

PURPOSE: Mechanical overloading is a key initiating condition for temporomandibular joint (TMJ) osteoarthritis (OA). The integrin-focal adhesion kinase (FAK) signaling axis is implicated in the mechanobiological response of cells through phosphorylation at Tyr397 (pFAK) but poorly defined in TMJ health and disease. We hypothesize that mechanical overloading disrupts TMJ homeostasis through dysregulation of FAK signaling. MATERIALS AND METHODS: To assess if FAK and pFAK are viable clinical targets for TMJ OA, peri-articular tissues were collected from patients with TMJ OA receiving a total TMJ replacement. To compare clinical samples with preclinical in vivo studies of TMJ OA, the joints of c57/bl6 mice were surgically destabilized and treated with and without inhibitor of pFAK (iFAK). FAK signaling and TMJ OA progression was evaluated and compared using RT-PCR, western blot, immunohistochemistry, and histomorphometry. To evaluate mechanical overloading in vitro, primary murine mandibular fibrochondrocytes were seeded in a 4% agarose-collagen scaffold and loaded in a compression bioreactor with and without iFAK. RESULTS: FAK/pFAK was mostly absent from the articular cartilage layer in the clinical sample and suppressed on the central condyle and elevated on the lateral and medial condyle in murine TMJ OA. In vitro, compressive loading lowered FAK/pFAK levels and elevated the expression of TGFß, NG2, and MMP-13. iFAK treatment suppressed MMP13 and Col6 and elevated TGFß, NG2, and ACAN in a load independent manner. In vivo, iFAK treatment moderately attenuated OA progression and increased collagen maturation. CONCLUSION: These data illustrate that FAK/pFAK is implicated in the signaled dysfunction of excessive mechanical loading during TMJ OA and that iFAK treatment can moderately attenuate the progression of cartilage degeneration in the mandibular condyle.

A Novel Prosthetically Driven Workflow Using Zygomatic Implants: The Restoratively Aimed Zygomatic Implant Routine.

PURPOSE: Zygomatic implants present a unique treatment option for patients with severe resorption of the maxilla; however, palatally positioned zygomatic implant platforms will result in a significant buccopalatal cantilever, speech disturbances, and unhygienic prosthesis contours. The purpose of the present study was to introduce a novel preoperative workflow to help attain predictable surgical and prosthetic outcomes with zygomatic implants. METHODS: To minimize prosthetic complications, an appropriate preoperative workup is imperative. A restoratively driven approach commonly used in traditional intra-alveolar implant dentistry has been adapted for zygomatic implant rehabilitation and described in the present report. RESULTS: With zygomatic implants, applying a prosthetically driven approach is possible. However, it involves a unique application of traditional biomechanical and soft tissue principles of implant dentistry and digital integration of the prosthetic and surgical treatment plans. CONCLUSIONS: Striving to attain zygomatic implant platforms as close as possible to the central fossae and cingulum of prosthetic teeth should be the goal when placing zygomatic implants. The restoratively aimed zygomatic implant routine introduced in the present report is a progressive and modern approach to prosthetically driven implant rehabilitation.

Does Immediate Inferior Alveolar Nerve Allograft Reconstruction Result in Functional Sensory Recovery in Pediatric Patients?

PURPOSE: Ablative mandibular resection may result in neurosensory loss and decreased quality-of-life, yet nerve reconstruction is not performed routinely for various reasons, including increased operative time. This study aimed to determine whether immediate inferior alveolar nerve (IAN) allograft reconstruction provides functional sensory recovery (FSR) in the pediatric age group. PATIENTS AND METHODS: This multicenter retrospective cohort study included pediatric patients who underwent mandibular resection with IAN discontinuity and a nerve allograft greater than 45 mm. A positive control group also was included, comprising pediatric patients who underwent mandibular resection without nerve reconstruction. The primary predictor variable was the use of a nerve allograft; a secondary variable was the time to achieve FSR using the Medical Research Council Scale. Comparisons were made to historical adult data. Statistical analysis of the comparison of neurosensory outcomes over time was measured by weighted values, repeated-measures analysis of variance, and the McNemar test. RESULTS: The study group consisted of 32 patients, 18 in the graft group and 14 in the non-graft group, without significant differences in age, gender, or nerve gap length. By 1 year, FSR was achieved in 100% in the study group and 0% in the control group (P < .00001). The median time to FSR was 75 days in the study group and 110 days in the historical adult study group. In comparison to historical adult data, there was a significant difference at 1 year, with adults at 87% FSR (P = .01562). CONCLUSIONS: Long-span nerve allografts were effective in restoring sensation to the lip and chin in pediatric patients, with 100% reaching FSR, whereas no patients without nerve reconstruction achieved FSR. Pediatric patients recovered to a higher level of FSR than adults at 1 year. Immediate IAN reconstruction in pediatric patients should be considered strongly when the mandible requires resection with sacrifice of the IAN.

"Monoblock" Occlusal Model to Enhance Occlusal Verification During Orthognathic Surgery.

Intraoperative verification of the planned occlusion is critical in ensuring the accuracy of orthognathic surgery. This step is limited to visual inspection, which can be especially challenging when the planned occlusal setup is less-than-stable. The authors introduce a cost-effective method of an accurate reproduction of the planned occlusion using additive manufacturing which can aid in intraoperative verification of positionally unstable occlusal setups. The authors present a case example, and discuss various technical considerations.

Does Metal Hypersensitivity Have Relevance in Patients Undergoing TMJ Prosthetic Replacement?

PURPOSE: Although concerns regarding implant-related metal hypersensitivity exist, no guidelines have been accepted for screening or treatment of patients with metal sensitivity before temporomandibular joint replacement (TMJR). The present study aimed to determine the trends in TMJR metal sensitivity screening and the effect of positive test results on patient treatment. MATERIALS AND METHODS: A questionnaire was distributed to members of the American Society of Temporomandibular Joint Surgeons and the European Society of Temporomandibular Joint Surgeons using a web-based data collection and analysis tool. The questions aimed to establish the screening methods used to establish a diagnosis of metal hypersensitivity and any changes in management when metal hypersensitivity had been documented. RESULTS: A total of 72 responses (32.43%) were collected through the survey, with respondents primarily practicing in the United States (47.22%). Of the participants, 75% believed that metal hypersensitivity occurs with TMJR and only 2.77% did not. Most agreed that patients should be questioned about any metal sensitivities before consideration for TMJR (91.66%), and 80.55% routinely asked their patients if they had a previous sensitivity to any metals. Nickel was the most commonly encountered metal allergen (64.28%). If a metal allergy were reported, 44.28% of surgeons would refer the patient to determine the specific metal allergen. The diagnosis for metal allergy was based primarily on patient signs and symptoms (52.85%) and an allergist or dermatologist consultation (44.28%). The lymphocyte transformation test was the test most used by respondents to confirm the diagnosis. Of the surgeons, 41.42% would choose to observe/monitor as their first choice for patients testing positive for metal hypersensitivity. In the case of a "mild" reaction to metal hypersensitivity testing, 54.28% would alter their implant choice to a nonreactive metal component. For "severe" reactions to preoperative metal hypersensitivity testing, 62.85% would alter their implant choice to a nonreactive metal component, and 22.85% would choose not to perform TMJR. CONCLUSIONS: The results from the present study have demonstrated that respondent TMJ surgeons agree that metal hypersensitivity occurs with TMJR. However, their approaches to screening and managing metal hypersensitivity vary. Further research of this topic is required to eventually develop specific management pre- and postoperative guidelines for the treatment of patients with metal sensitivities.

How Accurate Is 3-Dimensional Computer-Assisted Planning for Segmental Maxillary Surgery?

PURPOSE: The 3-dimensional (3D) accuracy of computer-assisted planning (CAP) of segmental maxillary osteotomies has seldom been reported with a comprehensive 3D analysis. The aim of the present study was to measure the accuracy of computer-planned segmental maxillary surgery and to identify the factors associated with accuracy. MATERIALS AND METHODS: The present retrospective, cross-sectional study investigated cone-beam computed tomography (CBCT) scans of patients who had undergone segmental maxillary osteotomy with CAP at a single center from January 2013 to October 2019. The predictor variables were age, gender, diagnosis, CAP method, type of maxillary segmentalization, surgeon, surgical sequence, and magnitude of planned and actual movements. The primary outcome variable was surgical discrepancy (linear differences between the actual and planned maxillary movements using CAP in the x, y, and z coordinates) at various 3D landmarks. The mean difference and absolute mean difference (AMD) were computed to estimate the direction and magnitude of the discrepancies. In addition, a 2.0-mm threshold of surgical discrepancy was used to determine clinically acceptable accuracy. The association between the predictor and outcome variables were analyzed statistically using correlation and regression analyses. RESULTS: The sample included 63 patients (mean age, 20.1 years; 42.9% male). The surgical discrepancy was similar for 2- and 3-piece segmental maxillary osteotomies. Overall, the AMD for all patients was 0.96 ± 0.69 mm transversely, 1.23 ± 0.83 mm vertically, and 1.16 ± 0.80 mm anteroposteriorly (P < .01 for all). The discrepancy between the actual and planned movements was within 2.0 mm for more than 80% of cases. The major predictor variable that affected surgical discrepancy was the magnitude of the actual surgical movements (P < .01). CONCLUSIONS: 3D CAP showed clinically acceptable accuracy for segmental maxillary osteotomies comparable to that of nonsegmental cases. Although the magnitude of actual surgical movements was shown to affect surgical accuracy, the sources of surgical discrepancies requires further investigation.