Three-dimensional cephalometric analysis of the maxilla: Analysis of new landmarks.

INTRODUCTION: Clinical evaluation of the midface including the paranasal and upper lip regions is highly subjective and complex. Traditional and 3-dimensional cephalometrics were not developed with the clinical appearance of these midfacial areas in mind and are therefore inappropriate surrogates for the clinical appearance of the midface, making them unsuitable as aids in diagnosing dentofacial deformities. The aim of this study was to evaluate traditional as well as newly defined landmarks and measurements and their correlation with clinical appearance of the midface. METHODS: Fifty-two subjects who underwent full-field cone-beam computed tomography were recruited for this study. A single examiner assessed each subject's midfacial region (paranasal and upper lip), and a second examiner obtained traditional and newly defined cephalometric measurements for each subject. Both examiners were blinded to each other's data throughout the study. Statistical analysis was performed to assess the correlations of the traditional and novel cephalometric measurements with clinical midfacial findings. The impact of the soft tissue thickness in the paranasal region was also analyzed. The performance of any classification derived from statistically significant variables was analyzed with the use of micro-F scores and area under the receiver operating characteristic curve (AUC). RESULTS: Both traditional (SNA) and newly defined measurements (SNANS, SNPR, SNNP, SNh) had no statistically significant correlation with clinical paranasal diagnosis. However, in the absence of upper lip procumbency or protrusion, SNNP and SNh had statistically significant correlations with clinical paranasal diagnosis (P = 0.047 and P = 0.003, respectively). For upper lip analysis, both traditional (SNA) and newly defined measurements (SNCEJ) had strong correlations with clinical upper lip diagnosis (P < 0.001). All statistically significant cephalometric variables had good intra- and interobserver reliability (correlation coefficients ≥0.972 and ≥ 0.968, respectively) except SNA, which had a low interobserver reliability (correlation coefficient 0.739). Fitted models for paranasal and upper lip analyses showed low micro-F scores, indicating low precision and recall. However, AUC values of 0.7019 and 0.6362 for the paranasal and upper lip analysis, respectively, suggest improved performance of the model when properly trained with a larger sample size. CONCLUSIONS: Newly defined measurements SNh and SNNP correlated with clinical paranasal diagnosis only in the absence of upper lip procumbency and protrusion. SNA and SNCEJ were strongly correlated with clinical upper lip diagnosis. However, fitted models based on this study sample yielded low micro-F scores, making the fitted models currently unsuitable for anything besides correlation with clinical findings. A larger sample size will be necessary to further clarify the potential roles of these measurements, especially given the reasonable AUC values. The findings of this study demonstrate the highly subjective and relative nature of midfacial diagnosis and the importance of clinical judgment despite the potential utility of some traditional and new measurements.

Senior Oral and Maxillofacial Surgery Resident Confidence in Performing Invasive Temporomandibular Joint Procedures.

PURPOSE: The purpose of this study was to evaluate the level of confidence that senior-level oral and maxillofacial surgery (OMS) residents have in the management of temporomandibular joint (TMJ) disorders, determine their exposure to various invasive TMJ procedures during training, and assess their confidence in performing those procedures on completion of residency. MATERIALS AND METHODS: A questionnaire was designed, and a link to a University of Illinois at Chicago Qualtrics Survey platform (Qualtrics, Provo, UT) was e-mailed to all program directors at Commission on Dental Accreditation-accredited OMS training programs in the United States. The program directors were asked to forward the 20-multiple-choice question anonymous survey to their senior-level residents for completion. The survey included the program's demographic characteristics, resident's confidence in assessing and managing patients with temporomandibular disorders (TMDs), resident's experience performing various invasive TMJ procedures, and whether the resident believed he or she had received sufficient education and clinical experience in the management of TMJ disorders. The data were collected and summarized by use of a standard spreadsheet analysis, as well as appropriate descriptive and analytical statistical tests. RESULTS: The response rate was 28.0%. Of the 56 respondents, 52 (92.9%) reported having received instruction in nonsurgical management of TMDs. All respondents confirmed that invasive TMJ procedures were performed in their program. The most commonly performed procedure was TMJ arthrocentesis (mean rating, 3.11), followed by open TMJ surgery (mean rating, 2.82). The least-performed invasive surgical procedure was autogenous total TMJ replacement surgery (mean rating, 1.39). Eighty percent of residents reported being comfortable managing the TMD patient. The only procedure with which the respondents were highly confident was TMJ arthrocentesis (mean rating, 3.89). CONCLUSIONS: This study suggests that confidence levels in the management of the TMD patient are related directly to the invasive TMJ procedure experience obtained during residency. This finding may have implications on the practice patterns of OMS surgeons as it relates to access to care for the TMD patient.

Is There an Association Between Comprehensive Basic Science Examination Score and Acceptance into an Oral and Maxillofacial Surgery Residency Program?

Sparse data exist regarding the association between applicants' Comprehensive Basic Science Examination (CBSE) scores and acceptance into an oral and maxillofacial surgery (OMFS) residency program. The aims of this study were to assess the association between applicants' CBSE scores and acceptance into one OMFS residency program; to determine the association between other applicant-related variables and acceptance into the program; and to identify the mean CBSE score of accepted applicants by their dental schools' American Association of Oral and Maxillofacial Surgeons (AAOMS) district. For this retrospective data analysis conducted in 2017, the study sample consisted of applicants to the University of Illinois at Chicago OMFS residency program for the application cycles of 2013-14, 2014-15, and 2015-16. The primary predictor variable was CBSE score. The primary outcome variable was acceptance to the program. A total of 477 applicants were in the sample. In the multivariate analysis, CBSE score was found to be significantly associated with an increased chance of acceptance into the program (OR=1.11, 95% CI: 1.08, 1.15; p<0.001). Other variables associated with acceptance, though to a non-significant degree, were age (p=0.01), dental school grade point average (GPA) (p=0.01), and number of externships completed prior to application (p=0.02). These findings may be useful for both applicants and program directors.

Patient morbidity among residents extracting third molars: does experience matter?

OBJECTIVE: The aim of this study was to evaluate the complication rates for third molar extractions, based on resident level within an oral and maxillofacial surgery program, and to identify the risk factors associated with postoperative complications following third molar extractions. STUDY DESIGN: Records of 1992 patients (5466 third molar extractions) over a 5-year period were reviewed. Data were collected by using appropriate Current Dental Terminology codes from July 1, 2011, to June 30, 2016. The cases were analyzed by using demographic statistics, Pearson χ2 test, and regression analysis. RESULTS: Of the total number of patients, 1855 had sufficient data available for analysis and inclusion in the study. There were 146 adverse outcomes. The common complication was alveolar osteitis. Nerve injuries and retained root tips were encountered less frequently. There was a significant association between the depth of impaction and developing a postoperative complication. There was a direct correlation between the level of resident training and the likelihood of an adverse outcome. CONCLUSIONS: The study indicates that there are identifiable risk factors associated with postoperative complications following third molar extraction in an oral and maxillofacial surgery residency program. These factors include location, depth of impaction, use of a surgical drill, and level of resident training, which are correlated directly with the development of negative outcomes following third molar extractions.