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.

Is Female Representation Increasing in Society and Journal Editorial Boards in Oral and Maxillofacial Surgery?

PURPOSE: Surgical specialties, including oral and maxillofacial surgery (OMS), are traditionally male-dominated fields. This study aimed to analyze the proportions of female surgeons on specialty society boards and journal editorial boards in OMS in the United States and to assess whether they were proportionate with female representation in OMS academic faculty between 2011 and 2020. METHODS: A retrospective cohort study was performed using information obtained from the websites of two major OMS journals and information obtained directly from six American specialty societies for OMS. The predictor variable was time. The outcome variable was gender. Temporal changes in the proportion of women on society and journal editorial boards were compared with those amongst full-time board-certified faculty. Chi-squared test and simple linear regression were used for statistical analyses. RESULTS: Between 2011 and 2020, the proportion of women on editorial and society boards was 6.7% (31 women among 463 editorial board members) and 7.8% (43 women among 553 society board members), respectively. The proportion of women on editorial boards increased from 4.5% in 2011 to 10.6% in 2020 (ß = 0.656 [95% confidence interval, 0.336-0.975], P = .001) and that of women on society boards increased from 4.3% in 2011 to 10.3% in 2020 (ß = 0.645 [95% confidence interval, 0.252-1.037], P = .005). The proportion of women on editorial boards in 2011-2012 was significantly lower than that in full-time board-certified faculty positions (4.3% vs 11.0%, P = .045), whereas by 2019-2020, there was no difference between the 2 groups (9.8% vs 12.5%, P = .454). Similarly, the proportion of women on society boards in 2011-2012 tended to be lower than that in full-time board-certified faculty positions (5.6% vs 11.0%, P = .111), while in 2019-2020, no difference was observed between the 2 groups (10.4% vs 12.5%, P = .531). CONCLUSION: The proportion of women on society and journal editorial boards in OMS remains low but has progressively increased from 2011 to 2020, resulting in proportionate female representation in these positions compared with the gender composition of academic faculty in recent years. The current upward trend of female representation in leadership positions will hopefully present more diverse opportunities and mentorship/role models for trainees.

Intrahepatic microbes govern liver immunity by programming NKT cells.

The gut microbiome shapes local and systemic immunity. The liver is presumed to be a protected sterile site. As such, a hepatic microbiome has not been examined. Here, we showed a liver microbiome in mice and humans that is distinct from that of the gut and is enriched in Proteobacteria. It undergoes dynamic alterations with age and is influenced by the environment and host physiology. Fecal microbial transfer experiments revealed that the liver microbiome is populated from the gut in a highly selective manner. Hepatic immunity is dependent on the microbiome, specifically the bacteroidetes species. Targeting bacteroidetes with oral antibiotics reduced hepatic immune cells by approximately 90%, prevented antigen-presenting cell (APC) maturation, and mitigated adaptive immunity. Mechanistically, our findings are consistent with presentation of bacteroidetes-derived glycosphingolipids to NKT cells promoting CCL5 signaling, which drives hepatic leukocyte expansion and activation, among other possible host-microbe interactions. Collectively, we reveal a microbial/glycosphingolipid/NKT/CCL5 axis that underlies hepatic immunity.