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 median lingual foramen in the era of orthognathic virtual surgical planning.

The median lingual foramen (MLF), which contains neurovascular bundles, is located in an area commonly considered safe for surgical procedures. However, published reports of severe complications after interventions in the mandibular symphysis area indicate the need for caution when approaching this region surgically. The aim of this study was to evaluate the vertical location of the MLF and the median lingual canal (MLC) by measuring the distances of these landmarks to the root apex of the lower central incisors (LCI) and to the menton cephalometric point (Me) on pre-orthognathic surgery cone beam computed tomography scans (N = 100). The results were analyzed in relation to the patients' type of deformity, age, sex, and number of foramina (single vs multiple). The median MLF-LCI and MLF-Me distances were 5.9 mm and 15.0 mm, respectively, while the mean MLC-LCI and MLC-Me distances were 9.7 mm and 11.6 mm, respectively. The mean LCI-Me distance was 21.3 mm, while the mean MLC length was 3.4 mm. Apart from the length of the MLC, the distances were all significantly greater in the male patients than in the female patients. The MLC-Me distance and MLC length differed significantly according to the number of foramina. In preoperative planning, the vertical locations of the MLF and respective MLC appear to be relevant for avoiding neurovascular complications.

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.

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.

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.

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.

Do positional changes of the inferior alveolar canal after sagittal split mandibular osteotomy affect neurosensory recovery?

The purpose of this study was to assess the pre- and postoperative position and dimensions of the inferior alveolar canal (IAC) following sagittal split osteotomy (SSO) and identify any association with postoperative neurosensory deficit (NSD) at 1 year. This retrospective cohort study enrolled consecutive patients who had SSO performed to correct skeletal malocclusion. The pre- and postoperative cone beam computed tomography data were superimposed to visualize differences in IAC position and dimensions. Subjective and objective neurosensory tests were used to determine NSD in the inferior alveolar nerve distribution. A total of 20 subjects were included. The preoperative distance from the lateral cortex of the IAC to the inner aspect of the lateral cortex of the mandible was significantly greater in sides with NSD when compared to sides without NSD (P = 0.01). A significantly greater reduction in the postoperative distance measurement was seen in sides with NSD when compared to sides without NSD (P = 0.01). The magnitude of mandibular movement was significantly increased in sides with NSD (P = 0.02). The preoperative location of the IAC, as well as certain changes in the mediolateral and vertical positions as a result of SSO, are risk factors for postoperative NSD.

Does a learning curve exist for accuracy in three-dimensional planning for maxillary positioning in bimaxillary orthognathic surgery?

The purpose of this study was to investigate the influence of time, and experience, on the accuracy of maxillary repositioning in bimaxillary orthognathic surgery performed using virtual surgical planning (VSP). Patients who had undergone bimaxillary orthognathic surgery were reviewed. Maxillary position on pre- and postoperative computed tomography scans was compared. The patients were divided into groups according to the year in which VSP was performed and surgery completed. Linear distances between upper jaw reference landmarks were measured in all three planes of space to determine accuracy between the preoperative VSP and the surgical outcome at various time points. One hundred subjects met the eligibility criteria for assessment and were allocated to groups: 2013 (n=10), 2014 (n=17), 2015 (n=39), 2016 (n=20), and 2017 (n=14). Overall, the results demonstrated improved precision in maxillary position over the years, with more accurate results in patients who underwent surgery in 2015, 2016, and 2017. Mean linear differences between planned and obtained results demonstrated more accurate results in the horizontal direction, followed by transverse and vertical directions. An overall average difference within 1mm was observed for 51.3% of the measurements included in the sample group. Time, and surgeon experience, can influence the accuracy of maxillary positioning in bimaxillary orthognathic surgery.

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.

Status of alloplastic total temporomandibular joint replacement procedures performed by members of the American Society of Temporomandibular Joint Surgeons.

The purpose of this study was to assess the number of alloplastic total temporomandibular joint replacement (TMJ TJR) devices implanted and the complications encountered by members of the American Society of Temporomandibular Joint Surgeons (ASTMJS). A questionnaire was developed using REDCap (Chicago, IL) and an on-line link was e-mailed four times over a 6-week period (February to March 2015) to all members of the ASTMJS. The questionnaire included eight questions related to the surgeon's TMJ TJR experience. A Likert scale was included to assess the respondents' opinions concerning the future demand for TMJ TJR and their thoughts on potential device improvements. The study sample was composed of 36 ASTMJS respondents (42.4%). TMJ TJR is performed successfully and in relatively high numbers by members of the American Society of Temporomandibular Joint Surgeons.

Mandible-first sequence in bimaxillary orthognathic surgery: a systematic review.

The sequencing of bimaxillary orthognathic surgery remains controversial, although the traditional maxilla-first approach is performed routinely. The goal of this study was to present a systematic review of the mandible-first sequence in bimaxillary orthognathic surgery, to provide data that may assist in the decision as to which jaw should undergo osteotomy first in bimaxillary orthognathic surgery cases. A literature search was conducted for articles published in the English language, reporting the use of the altered sequence for bimaxillary orthognathic surgery (mandible-first), using the following descriptors: 'orthognathic' and 'double-jaw', 'orthognathic' and 'two-jaw', 'orthognathic' and 'mandible-first', 'orthognathic' and 'bimaxillary'. Eight hundred eighty-seven abstracts were initially identified and were evaluated for inclusion according to the proposed inclusion criteria. After evaluation of these abstracts and relevant references, six publications met the criteria for consideration. Performing mandible-first surgery in bimaxillary orthognathic cases dates back to the 1970s; however the decision regarding the jaw to be operated on first seems to rely on accurate preoperative planning based upon the surgeon's experience and preference. While there appear to be significant theoretical advantages to support the use of the altered orthognathic sequence (mandible-first), future prospective studies on its reliability, accuracy, and short- and long-term outcomes are required.

Transoral endoscopic-assisted styloidectomy: How should Eagle syndrome be managed surgically?

Eagle syndrome, or calcification of the stylohyoid ligament, is a rare condition that may present a clinical diagnostic dilemma for those unfamiliar with its existence and its typical presenting signs and symptoms. Management of this disease process may involve either non-surgical or surgical treatment options. When surgery is indicated, the choice of a specific surgical modality is highly variable and is generally dependent upon individual surgeon preference and experience, since the location of the styloid process is consistent between patients, and the required surgical access is also similar depending upon the specific surgical plan. This paper reports a case of Eagle syndrome managed with a transoral endoscopic-assisted approach, explores the advantages and disadvantages of each surgical approach, and reviews the literature regarding surgical management options for Eagle syndrome.

Accuracy of perioperative mandibular positions in orthognathic surgery.

Mandibular position is an important parameter used for the diagnosis of dentofacial deformities, as well as for orthognathic surgery planning and execution. Centric relation (anterior and superior relationship of the mandibular condyles interposed by the thinnest portion of their disks against the articular eminencies), centric occlusion (when lower teeth contact upper teeth at centric relation), and maximal intercuspation (complete interdigitation of lower and upper teeth) are not often addressed as factors that influence the results of orthognathic surgery, although these relationships are critical to ensure accuracy during the surgery. The present study assessed occlusal measurements taken before and after the induction of general anaesthesia from consecutive orthognathic surgery subjects. The variables assessed included the differences between these occlusal measurements, patient age, gender, type of deformity, and type of proposed orthognathic surgical procedure. The results demonstrated statistically significant differences for mandibular retrusion from maximal intercuspation to centric occlusion position, whereas the mandible appeared not to change significantly from centric occlusion after the induction of general anaesthesia. Patient age and the type of deformity appeared to influence the results. While in most instances centric occlusion can be adequately reproduced under general anaesthesia, for some specific orthognathic cases more accurate results might be obtained if the mandible-first sequence is used.

Is there consistency in cephalometric landmark identification amongst oral and maxillofacial surgeons?

There may be significant variation amongst oral and maxillofacial surgeons (OMFS) in the identification and placement of cephalometric landmarks for orthognathic surgery, and this could impact upon the surgical plan and final treatment outcome. In an effort to assess this variability, 10 lateral cephalometric radiographs were selected for evaluation by 16 OMFS with different levels of surgical knowledge and experience, and the position of 21 commonly used cephalometric landmarks were identified on radiographs displayed on a computer screen using a computer mouse on a pen tablet. The database consisted of real position measurements (x, y) to determine the consistency of landmark identification between surgeons and within individual surgeons. Inter-examiner analysis demonstrated that most landmark points had excellent reliability (intra-class correlation coefficient >0.90). Regardless of the level of surgeon experience, certain landmarks presented consistently poor reliability, and intra-examiner reliability analysis demonstrated that some locations had a higher average difference for both x and y axes. In particular, porion, condylion, and gonion showed poor agreement and reliability between examiners. The identification of most landmarks showed some inconsistencies within different parameters of evaluation. Such variability among surgeons may be addressed by the consistent use of high-quality images, and also by periodic surgeon education of the definition of the specific landmarks.

Metastatic pancreatic adenocarcinoma to the mandibular condyle: a rare clinical presentation.

Metastatic disease to the oral cavity is rare, representing only 1-8% of oral malignancies, and involvement of the mandibular condyle is even less prevalent. In a recent literature review of 796 cases of metastatic disease to the oral cavity, only 39 (13.8%) involved the condyle. This report is a unique case of metastatic pancreatic adenocarcinoma to the condyle. There are only 5 documented cases of metastatic pancreatic adenocarcinoma to the oral cavity, one of which metastasized to the condyle. This is an important case because metastatic lesions to the condyle may mimic temporomandibular joint disorders making clinical diagnosis and decision-making extremely challenging for the oral and maxillofacial surgeon. The requirement for arrival at an appropriate and prompt diagnosis is crucial for determining the most appropriate treatment regimens and improved outcomes. Additionally, in approximately 33% of cases, the oral metastatic lesion may be the first indication of an undiscovered distant primary tumor, making timely evaluation and treatment critical from an oncologic perspective.

Expanded polytetrafluoroethylene entubulation of the rabbit inferior alveolar nerve.

OBJECTIVE: The purpose of this study was to evaluate the use of an expanded polytetrafluoroethylene conduit in the treatment of a 6. 0-mm gap in the rabbit inferior alveolar nerve and compare the results with those of an autogenous interpositional tibial nerve graft. STUDY DESIGN: The inferior alveolar nerves of 5 adult New Zealand White female rabbits (10 nerves) were exposed bilaterally, and a 6-mm segment of each nerve was resected. On one side, chosen at random, the gap was immediately bridged through use of an 8.0 x 2. 0-mm expanded polytetrafluoroethylene conduit; on the other side, the gap was grafted with an autogenous tibial nerve graft. Two randomly selected nerves served as sham-dissected controls. At 15 weeks after surgery, the animals were killed and the entire nerve segments were harvested and prepared according to standard fixation and embedding techniques. The sections were examined histomorphometrically to quantify the degree of axonal regeneration through definition of fascicular number, total fascicular surface area, axonal density, and mean axonal diameter at 3 locations along the repair site. RESULTS: Light microscopic examination revealed the presence of disorganized neural tissue in both groups, with slightly more fibrovascular interfascicular tissue in the expanded polytetrafluoroethylene group. Histomorphometric analysis revealed no significant differences between groups for most of the measured variables. The mean axonal diameter varied between groups, and the fascicular number was greater in the expanded polytetrafluoroethylene group at the middle site. CONCLUSIONS: This study demonstrates that regeneration of the inferior alveolar nerve can occur across a 6.0-mm gap through an expanded polytetrafluoroethylene tube with results comparable to those of an autogenous nerve graft, significant donor site morbidity being avoided. The significant differences between groups were probably due to greater containment of regenerating axonal fibers in the expanded polytetrafluoroethylene group.

Low-level laser effect on neurosensory recovery after sagittal ramus osteotomy.

OBJECTIVES: This study examined the potential benefit of perioperative and short-term postoperative low-level laser (LLL) therapy on objective and subjective neurosensory recovery after bilateral sagittal split osteotomy surgery. METHODS: Six consecutive patients undergoing bilateral sagittal split osteotomy procedures were enrolled in this prospective study. A complete preoperative clinical neurosensory test, consisting of brush stroke directional discrimination, 2-point discrimination, contact detection, pin prick nociception, and thermal discrimination, was performed on each patient; and a subjective assessment of neurosensory function was made by using a visual analog scale (VAS). The protocol for LLL treatments consisted of real LLL (4 x 6 J per treatment) along the distribution of the inferior alveolar nerve at 4 sites, for a total of 7 treatments, delivered immediately before surgery; at 6 and 24 hours after surgery; and on postoperative days 2, 3, 4, and 7. The clinical neurosensory test and VAS were completed just before each of the treatment sessions and on days 14 and 28, by one examiner. RESULTS: When the results of the patients treated with LLL were compared with published values for neurosensory recovery after orthognathic surgery, there was a significant acceleration in the time course, as well as in the magnitude, of neurosensory return. Brush stroke directional discrimination approached normal values by 14 days, whereas 2-point discrimination and contact detection showed significant improvement at 14 days and returned to near-normal values by 2 months. The results of thermal discrimination and pin prick nociception revealed few neurosensory deficits; however, those patients who were affected showed a slower recovery trend and remained neurosensory-deficient for up to 2 months. The VAS analysis revealed a rapidly progressive improvement in subjective assessment, showing a 50% deficit at 2 days and only a 15% subjective deficit at 2 months. CONCLUSIONS: This study demonstrates that neurosensory recovery after bilateral sagittal split osteotomy procedures can be significantly improved, both in terms of time course and magnitude of return of function, with the adjunctive use of LLL therapy.