Orthodontic correction of anterior open bite using skeletal anchorage: systematic review and meta-analysis

The purpose of this study was to investigate the scientific evidence on the short- and long-term effects of orthodontic correction of anterior open bite (AOB) using skeletal anchorage (SA). Clinical studies on the use of SA for AOB in patients with permanent dentition, or at least 12 years of age, were searched. Short- and long-term (≥2 years) outcomes were collected. Mean differences were calculated from pooled data. Twenty-four eligible articles with a total of 362 subjects were selected for inclusion in the meta-analysis. There was a significant increase in overbite (3.88 mm, P < 0.001) and maxillary molar intrusion (-2.15 mm, P < 0.001). The mandible showed counterclockwise rotation with anterosuperior chin movement (all P < 0.001). Long term, the decrease in overbite was 19.9% and decrease in molar intrusion was 22.9%. The decrease in the mandibular projection was 14.6% for ANB (A-point-nasion-B-point angle) and 46.2% for mandibular anteroposterior position. The overall risk of bias in the included studies was rated as moderate to high, and publication bias existed for several key variables. SA for maxillary molar intrusion effectively improved dental and skeletal outcomes, but there was a long-term decrease in overbite and maxillary molar position. The variable data quality, heterogeneity, and publication bias in investigated outcomes are limitations in interpreting the findings.

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.

Does surgical volume correlate with outcomes in TMJ replacement surgery?

OBJECTIVE

To survey oral and maxillofacial surgeons (OMS) who perform temporomandibular joint replacement (TMJR) to determine whether length of surgery, specific TMJR protocols, or the incidence of complications are related to experience and case volume.

STUDY DESIGN

An anonymous electronic survey was emailed to 407 surgeon members of the American Association of Oral and Maxillofacial Surgeons, American Society of Temporomandibular Joint Surgeons, and European Society of Temporomandibular Joint Surgeons known to have TMJR experience via publications or reputation. The descriptive survey contained multiple choice and open-ended questions. Descriptive statistics were computed for each variable for data analysis.

RESULTS

Forty-nine surgeons completed the survey. The average stock TMJR cases included 54.6% unilateral and 50.5% bilateral cases. The average custom TMJR cases included 50.5% unilateral and 49.5% bilateral cases. Average procedure time for stock TMJR was 2.86 hours for unilateral, and 5.30 hours for bilateral cases. The average procedure time for a custom TMJR was 2.75 hours for unilateral, and 4.87 hours for bilateral cases. Average duration of hospital stay for stock and custom TMJR cases was 1.49 and 1.41 days (unilateral), and 1.98 and 1.95 days (bilateral).

CONCLUSIONS

This study provides some pilot data that demonstrates that the length of surgery, specific TMJR surgical protocols, and the incidence of complications may be related to surgeon TMJR experience and case volume.

Exploring the relationship between the number of systematic reviews and quality of evidence: an orthognathic surgery-based study

OBJECTIVE

We analyzed the quality and quantity of systematic reviews (SRs) of orthognathic surgery, the most frequently published topic in maxillofacial surgery.

STUDY DESIGN

We searched the PubMed database for SRs of orthognathic surgery with no restriction on the language of publication date. We assessed the certainty of evidence presented according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol and the Leiden Manifesto using the Grading of Recommendations Assessment, Development, and Evaluation approach. We analyzed the data using descriptive statistics, Pearson´s correlation test, and linear regression.

RESULTS

Of the 171 SRs evaluated, approximately one fifth presented evidence with a high level of certainty. The number of orthognathic surgery SRs has been increasing, and many SRs were published after very similar topics had already been published. There is no relationship between the impact factor and the certainty of evidence.

CONCLUSIONS

An excessive number of SRs of orthognathic surgery are published, and many SRs are superfluous, simply reporting previous findings. Clinicians should not base treatment decisions solely on the evidence presented in SRs, and journal editors and reviewers should evaluate these SRs more critically, particularly when they address topics that have already been covered in the literature.

What is the angular accuracy of regional voxel-based registration for segmental Le Fort I and genioplasty osteotomies?

Among the accuracy analysis techniques for orthognathic surgery, regional voxel-based registration (R-VBR) has robust data, but remains unvalidated for smaller jaw segments. The purpose of this study was to validate the angular accuracy of R-VBR for segmental Le Fort I (SLFI) and genioplasty osteotomies. Postoperative cone beam computed tomography (CBCT) of consecutive patients with three-piece SLFI or genioplasties was rotated to a known pitch/roll/yaw (P/R/Y). Using R-VBR, a copy of the raw CBCT was superimposed onto the rotated CBCT at four mutual regions of interest (ROI): anterior, right posterior, and left posterior maxilla, and chin. The P/R/Y of each was subtracted from those of the rotated CBCT to calculate the angular error. The predictor and outcome variables were ROI and absolute angular error, respectively. The accuracy threshold was 0.5°. Ten SLFI and 34 genioplasties were analyzed based on the sample size calculation. The one-sample t-test and Wilcoxon signed rank test were applied in the analysis. The mean absolute error was 0.20-0.54° for the maxillary segments (all P ≤ 0.01) and 0.83-2.51° for the genioplasty segments (all P < 0.001). R-VBR has variable angular accuracy for SLFI osteotomies and may be insufficient for genioplasty. The findings may allow the design and interpretation of studies on SLFI and genioplasty with greater rigor, thereby contributing to minimizing the discrepancy between planned and achieved outcomes.

The Opioid Analgesic Reduction Study (OARS) Pilot: A Double-Blind Randomized Multicenter Trial

BACKGROUND

With addiction rates and opioid deaths increasing, health care providers are obligated to help stem the opioid crisis. As limited studies examine the comparative effectiveness of fixed-dose combination nonopioid analgesia to opioid-containing analgesia, a comparative effectiveness study was planned and refined by conducting a pilot study.

METHODS

The Opioid Analgesic Reduction Study (OARS) pilot, a stratified, randomized, multisite, double-blind clinical trial, was designed to test technology and procedures to be used in the full OARS trial. Participants engaged in the full protocol, enabling the collection of OARS outcome data. Eligible participants reporting to 1 of 5 sites for partial or full bony impacted mandibular third molar extraction were stratified by biologic sex and randomized to 1 of 2 treatment groups, OPIOID or NONOPIOID. OPIOID participants were provided 20 doses of hydrocodone 5 mg/acetaminophen 300 mg. NONOPIOID participants were provided 20 doses of ibuprofen 400 mg/acetaminophen 500 mg. OARS outcomes data, including pain experience, adverse effects, sleep quality, pain interference, overall satisfaction, and remaining opioid tablets available for diversion, were collected via surveys, electronic medication bottles, eDiary, and activity/sleep monitor.

RESULTS

Fifty-three participants were randomized with 50 completing the OARS pilot protocol. Across all outcome pain domains, in all but 1 time period, NONOPIOID was better in managing pain than OPIOID (P < 0.05 level). Other outcomes suggest less pain interference, less adverse events, better sleep quality, better overall satisfaction, and fewer opioid-containing tablets available for diversion.

DISCUSSION

Results suggest patients requiring impacted mandibular third molar extraction would benefit from fixed-dose combination nonopioid analgesia.

KNOWLEDGE TRANSFER STATEMENT

Study results suggest fixed-dose nonopioid combination ibuprofen 400 mg/acetaminophen 500 mg is superior to opioid-containing analgesic (hydrocodone 5 mg/acetaminophen 500 mg). This knowledge should inform surgeons and patients in the selection of postsurgical analgesia.

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.

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.

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 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.

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.

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.

Should orthognathic surgery be performed in growing patients? A scoping review

The aim of this study was to determine whether the benefits of orthognathic surgery in a growing individual outweigh its risks. A scoping review was performed according to the PRISMA-ScR guideline. A bibliographic search from MEDLINE, Cochrane Library and LILACS was conducted until February 1, 2022. Scientific publications which reported orthognathic surgery in individuals under 18 years of age were considered. Inclusion criteria were performed according to PICOS model: do individuals with dentofacial deformity submitted to orthognathic surgery with an immature skeleton other than waiting growth cessation have overall benefits over any possible pos-operative consequences? Predictor of interest was growth status and outcome variables were positive benefits or negative consequences related to orthognathic surgery. Two reviewers screened records independently, and any disagreement between them was resolved by a third reviewer. Eligible studies were compiled into an extraction data form and were verified for validity and reliability. Risk of bias between studies was carried out using Review Manager. A total of 15 articles were included in this scoping review, comprising retrospective studies (9), case reports (3), and surveys (3). The topics covered varied from assessment of the functional needs, role, quality of life after orthognathic surgery, impact on growth, relation with temporomandibular joint surgical treatments, minimal referral age for surgery by orthodontists and complex cranio-maxillofacial deformities. Due to the heterogeneity of the articles, it was not possible to perform a meta-analysis. Within the limitations of the study it seems that the existing evidence seems favorable towards the intervention, improving quality of life in growing individuals, even at the risk of a second surgery.

The Opioid Analgesic Reduction Study (OARS)-a comparison of opioid vs. non-opioid combination analgesics for management of post-surgical pain: a double-blind randomized clinical trial

Background

Everyday people die unnecessarily from opioid overdose-related addiction. Dentists are among the leading prescribers of opioid analgesics. Opioid-seeking behaviors have been linked to receipt of initial opioid prescriptions following the common dental procedure of third molar extraction. With each opioid prescription, a patient’s risk for opioid misuse or abuse increases. With an estimated 56 million tablets of 5 mg hydrocodone annually prescribed after third molar extractions in the USA, 3.5 million young adults may be unnecessarily exposed to opioids by dentists who are inadvertently increasing their patient’s risk for addiction.

Methods

A double-blind, stratified randomized, multi-center clinical trial has been designed to evaluate whether a combination of over-the-counter non-opioid-containing analgesics is not inferior to the most prescribed opioid analgesic. The impacted 3rd molar extraction model is being used due to the predictable severity of the post-operative pain and generalizability of results. Within each site/clinic and gender type (male/female), patients are randomized to receive either OPIOID (hydrocodone/acetaminophen 5/300 mg) or NON-OPIOID (ibuprofen/acetaminophen 400/500 mg). Outcome data include pain levels, adverse events, overall patient satisfaction, ability to sleep, and ability to perform daily functions. To develop clinical guidelines and a clinical decision-making tool, pain management, extraction difficulty, and the number of tablets taken are being collected, enabling an experimental decision-making tool to be developed.

Discussion

The proposed methods address the shortcomings of other analgesic studies. Although prior studies have tested short-term effects of single doses of pain medications, patients and their dentists are interested in managing pain for the entire post-operative period, not just the first 12 h. After surgery, patients expect to be able to perform normal daily functions without feeling nauseous or dizzy and they desire a restful sleep at night. Parents of young people are concerned with the risks of opioid use and misuse, related either to treatments received or to subsequent use of leftover pills. Upon successful completion of this clinical trial, dentists, patients, and their families will be better able to make informed decisions regarding post-operative pain management.

Trial registration

ClinicalTrials.govNCT04452344. Registered on June 20, 2020

NG2/CSPG4 regulates cartilage degeneration during TMJ osteoarthritis

Changes in the mechanical homeostasis of the temporomandibular joint (TMJ) can lead to the initiation and progression of degenerative arthropathies such as osteoarthritis (OA). Cells sense and engage with their mechanical microenvironment through interactions with the extracellular matrix. In the mandibular condylar cartilage, the pericellular microenvironment is composed of type VI collagen. NG2/CSPG4 is a transmembrane proteoglycan that binds with type VI collagen, and has been implicated in the cell stress response through mechanical loading-sensitive signaling networks including ERK 1/2. The objective of this study is to define the role of NG2/CSPG4 in the initiation and progression of TMJ OA and to determine if NG2/CSPG4 engages ERK 1/2 in a mechanical loading dependent manner. In vivo, we induced TMJ OA in control and NG2/CSPG4 knockout mice using a surgical destabilization approach. In control mice, NG2/CSPG4 is depleted during the early stages of TMJ OA and NG2/CSPG4 knockout mice have more severe cartilage degeneration, elevated expression of key OA proteases, and suppression of OA matrix synthesis genes. In vitro, we characterized the transcriptome and protein from control and NG2/CSPG4 knockout cells and found significant dysregulation of the ERK 1/2 signaling axis. To characterize the mechanobiological response of NG2/CSPG4, we applied mechanical loads on cell-agarose-collagen scaffolds using a compression bioreactor and illustrate that NG2/CSPG4 knockout cells fail to mechanically activate ERK 1/2 and are associated with changes in the expression of the same key OA biomarkers measured in vivo. Together, these findings implicate NG2/CSPG4 in the mechanical homeostasis of TMJ cartilage and in the progression of degenerative arthropathies including OA.

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 TGFβ, NG2, and MMP-13. iFAK treatment suppressed MMP13 and Col6 and elevated TGFβ, 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.

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.

Are we able to predict airway dimensional changes in isolated mandibular setback?

The goal of this study was to determine whether a relationship exists between the amount of mandibular setback and the amount of airway dimensional changes. Records and cone beam computed tomography (CBCT) of patients who had undergone isolated bilateral sagittal split osteotomy setback between January 1, 2013 and March 16, 2020 at a single institution were reviewed retrospectively. The primary outcome variable was upper airway volume dimension change, and the predictor variable was the magnitude of mandibular setback as measured by six different methods. Thirty-one patients were included in the study, with a mean mandibular setback ranging from 1.41 mm to 6.11 mm. None of the predictor variables showed an association with oropharyngeal (P = 0.54) or hypopharyngeal (P = 0.33) volume. Stepwise regression analysis failed to show any significant relationships. Similarly, there was no statistically significant association between any of the predictor variables and oropharyngeal (P = 0.44) or hypopharyngeal (P = 0.74) minimum axial area. The results showed that no correlation exists between the magnitude of mandibular setback and the amount of static airway dimensional changes; therefore, it may not be possible to predict whether obstructive sleep apnea will develop following mild to moderate mandibular setback based upon CBCT measurements.

Management of Traumatic Trigeminal and Facial Nerve Injuries

In the area of craniomaxillofacial trauma, neurosensory disturbances are encountered commonly, especially with regard to the trigeminal and facial nerve systems. This article reviews the specific microanatomy of both cranial nerves V and VII, and evaluates contemporary neurosensory testing, current imaging modalities, and available nerve injury classification systems. In addition, the article proposes treatment paradigms for management of trigeminal and facial nerve injuries, specifically with regard to the craniomaxillofacial trauma setting.

How Many Oral Surgeons Does It Take to Classify a Nerve Injury?

PURPOSE

There is inconsistency in clinical grading of peripheral trigeminal nerve (TN5) injuries that impact patient care. The study goal is to assess the current status of evaluation and classification of TN5 injuries by oral and maxillofacial surgeons (OMSs).

PATIENTS AND METHODS

A cross-sectional study design used an electronic survey to 100 selected OMSs to determine their clinical TN5 injury practice, including neurosensory testing, confidence level with current protocols, and evaluation and treatment of a hypothetical TN5 injury case. The target sample was enhanced to reduce type 2 error, assuming prior experience in the diagnosis and management of TN5 injuries.

RESULTS

The sample was composed of 90 respondents. Nerve injury classification systems used by OMSs include Seddon (44%), Sunderland (70%), and Medical Research Council Scale (31%). Neurosensory testing protocols varied considerably among survey respondents. A sample case for Medical Research Council Scale grading produced inconsistent and inaccurate results. There was no consensus on TN5 injury management, and recommendations for timely nerve repair varied from 1 month to up to 1 year after injury. Half of the respondents stated that OMSs are not adequately prepared to assess inferior alveolar/lingual nerve injuries, and most oral-maxillofacial surgery respondents evaluate fewer than 10 TN5 injuries each year. Most OMSs (92%) have had a temporary inferior alveolar/lingual nerve injury, while 54% have had a permanent injury; of which, 21% required microsurgical repair. The majority of OMSs (74%) believed that a uniform TN5 injury classification system is needed.

CONCLUSIONS

Within the oral-maxillofacial surgery target group experienced in evaluation of TN5 injuries, respondents do not feel confident in the assessment of these injuries. There is inconsistency in evaluation methods, and there is agreement that a unified classification system is needed for more efficient patient evaluation and reporting of outcomes in the literature. The Medical Research Council Scale and clinical neurosensory testing is preferred for evaluation of TN5 injuries.

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.

Does early repair of trigeminal nerve injuries influence neurosensory recovery? A systematic review and meta-analysis

This systematic review and exploratory meta-analysis of the available evidence was performed to examine whether early nerve repair of lingual nerve (LN) and inferior alveolar nerve (IAN) injuries has an effect on neurosensory recovery. A literature search was conducted to identify relevant studies meeting the inclusion criteria. Two reviewers independently evaluated the methodological quality of the included studies and the risk of bias using the ROBINS-I quality assessment tool. For the quantitative analysis, data were pooled using the Mantel-Haenszel random-effects method due to the clinical heterogeneity across the studies. Sensitivity and subgroup analyses were performed based upon the group definition of timing from injury to nerve repair, with breakpoints of 2, 3, and 6 months. A total 1236 citations were identified, with a final 13 studies included in the systematic review. A clear definition of 'early' versus 'late' repair was not reported in six studies, allowing only seven to be included in the meta-analysis. The effect of early repair on functional sensory recovery was found not to be significant in nine studies, while four studies found a significant effect of early intervention. The meta-analysis showed a combined success rate of 93.0% for the early group and 78.5% for the late group. The odds of improvement were 5.49 (95% confidence interval 1.40-21.45) in the 3-month breakpoint studies and 2.28 (95% confidence interval 1.05-4.98) in the 6-month studies. A trend towards early repair achieving better functional sensory recovery outcomes was observed, but the specific time period is unknown.

Is There a Role for Absorbable Metals in Surgery? A Systematic Review and Meta-Analysis of Mg/Mg Alloy Based Implants

Magnesium (Mg) alloys have received attention in the literature as potential biomaterials for use as absorbable implants in oral and maxillofacial and orthopedic surgery applications. This study aimed to evaluate the available clinical studies related to patients who underwent bone fixation (patients), and received conventional fixation (intervention), in comparison to absorbable metals (comparison), in terms of follow-up and complications (outcomes). A systematic review and meta-analysis were performed in accordance with the PRISMA statement and PROSPERO (CRD42020188654), PICO question, ROBINS-I, and ROB scales. The relative risk (RR) of complications and failures were calculated considering a confidence interval (CI) of 95%. Eight studies (three randomized clinical trial (RCT), one retrospective studies, two case-control studies, and two prospective studies) involving 468 patients, including 230 Mg screws and 213 Titanium (Ti) screws, were analyzed. The meta-analysis did not show any significant differences when comparing the use of Mg and Ti screws for complications (p = 0.868). The estimated complication rate was 13.3% (95% CI: 8.3% to 20.6%) for the comparison group who received an absorbable Mg screw. The use of absorbable metals is feasible for clinical applications in bone surgery with equivalent outcomes to standard metal fixation devices.

"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.

Is There a Correlation Between Comprehensive Basic Science Examination and United States Medical Licensure Examination Step 1 Performance Among Oral and Maxillofacial Surgery Residents?

PURPOSE

Oral and maxillofacial surgery (OMS) applicant Comprehensive Basic Science Examination (CBSE) scores are scrutinized by residency programs and medical schools because of their perceived predictive value for United States Medical Licensure Examination (USMLE) Step 1 performance. The purpose of this study was to answer the following question: Is there a correlation between the OMS applicant's CBSE score and his or her later USMLE Step 1 score?

MATERIALS AND METHODS

We e-mailed all current 45 dual-degree OMS residency programs to request participation in the study. Participating programs submitted residents' CBSE scores and USMLE Step 1 scores.

RESULTS

Of 45 United States-based, dual-degree OMS residency programs, 23 (51%) enrolled in the study, including data for 152 residents from 2012 to 2018. The mean CBSE score was 71 (range, 47 to 99). The mean USMLE Step 1 score was 220 (range, 177 to 266). The Pearson correlation coefficient for the relationship between the CBSE and USMLE Step 1 scores was 0.36. The overall USMLE pass rate was 97%. On the USMLE Step 1, OMS residents outperformed their translated CBSE score by an average of 15 points. Of the 50 residents (33%) with a translated CBSE score below the passing level, 94% passed the USMLE Step 1. Residents who had a translated passing CBSE score outscored residents with a translated failing score by 14 points when taking the USMLE Step 1 (225 vs 211).

CONCLUSIONS

Although no statistically significant difference in the USMLE Step 1 pass rates was found between OMS residents with a translated passing CBSE score and those with a translated failing CBSE score, a weak positive correlation was noted between CBSE and USMLE Step 1 scores. These data do not support the use of a certain cutoff CBSE score for OMS applications by OMS program directors, especially as it pertains to interview offers.

What information do patients recall from the third molar surgical consultation?

The aim of this study was to determine whether the use of a professionally prepared educational video on third molar extraction enhances comprehension and retention of general and informed consent information. A prospective cohort study of adult patients undergoing consultation followed by extraction of third molars in the Oral and Maxillofacial Surgery Clinic, University of Illinois at Chicago was completed. At the initial consultation, the subjects viewed an educational video and received specific verbal individual information about their case. A written examination (group 1) was then completed; a subgroup of the subjects (group 2) was selected randomly to complete the same examination at the next visit prior to the procedure. The primary predictor variable was utilization of the video. The primary outcome variable was comprehension of information regarding third molars, assessed by examination scores. The secondary outcome variable was retention of the information, assessed by repeat examination scores. One hundred adults (34 male, 66 female; group 1) completed the examination at least once; 54 (19 male, 35 female) completed both examinations (group 2). Correct responses ranged from 64% to 100% in group 1 and from 37% to 100% in group 2. In group 2, all questions answered incorrectly at the first visit were answered correctly at the second visit, without any additional information being provided. Patient comprehension and retention of pertinent pre-surgical information is poor, despite use of an educational video to supplement the usual verbal consultation. These results confirm those of prior studies and may have medico-legal implications regarding the informed consent process for third molar surgery.

Interceptive Dentofacial Orthopedics (Growth Modification)

Although all dentofacial deformities involve deviation of skeletal and dental units that require correction, the timing and method of treatment can vary considerably. Growth is a key consideration when managing dentofacial deformities, because it has a direct impact on the timing and method of management. Some deformities may be intercepted and managed during growth, whereas others can only be definitively managed after cessation of growth. This article focuses on clinical considerations of growth in managing dentofacial deformities, and discusses methods of growth evaluation and interceptive orthodontic management strategies in different types of dentofacial deformities.