Utility of BRAF V600E immunohistochemistry in the diagnosis of mandibular ameloblastomas.

Ameloblastoma, odontogenic keratocyst (OKC), and dentigerous cyst (DC) can have similar radiographic and histological appearances. The purpose of this study was to determine the utility of BRAF immunohistochemistry in discerning mandibular ameloblastomas from OKCs and DCs. This retrospective cohort study included patients treated between 1998 and 2018. Inclusion criteria include incisional biopsy-proven mandibular ameloblastoma, OKC, or DC, and sufficient tissue for immunohistochemistry. The primary predictor variable was the type of lesion. The primary outcome variable was the presence/absence of BRAF V600E immunoreactivity. The cohort consisted of 43 patients (19 female, 24 male; mean age 48 ± 17 years). There were 22 ameloblastomas, 11 OKCs, and 10 DCs. Among ameloblastomas, 68.2% (15/22) stained positive for BRAF V600E; no OKC or DC was positive (P < 0.001). By subtype, the majority of the follicular (83.3%), unicystic (83.3%), desmoplastic (66.7%), and acanthomatous (100%) subtypes were positive, but only 33.3% of the plexiform subtype were positive. BRAF immunohistochemistry may be a useful adjunct in the differentiation of ameloblastoma from OKCs and DCs on incisional biopsies. It may be particularly useful for small samples with a prominent cystic component or equivocal histopathology. Mandibular lesions that are BRAF immunohistochemistry positive are unlikely to be DCs or OKCs.

Accuracy of skeletal scintigraphy for the evaluation of mandibular growth disorders: a systematic review.

Bone scans, reflecting blood flow and metabolic activity in a region of interest, are frequently used to evaluate mandibular growth disorders. Increased uptake is a non-specific finding and can occur as a result of multiple causes. The correlation between radioactive tracer uptake and growth activity has not been consistently demonstrated. The aim of this study was to assess the accuracy of planar skeletal scintigraphy (SS), single-photon emission computed tomography (SPECT), and SPECT with computed tomography (CT) images (SPECT/CT) in detecting abnormal mandibular growth activity compared to clinical and radiographic/tomographic methods (reference standard) and histologic findings. A systematic review was conducted following the PRISMA guidelines. Sensitivity, specificity, and accuracy were calculated for planar SS, SPECT, and SPECT/CT. Compared to the reference standard, SPECT/CT had the best diagnostic accuracy (76.5% sensitivity, 90.4% specificity, 83.2% accuracy), followed by planar SS (81.8% sensitivity, 84.5% specificity, 83.0% accuracy) and SPECT (77.7% sensitivity, 72.4% specificity, 74.5% accuracy). The results of this study indicate that SPECT/CT has the best clinical correlation, but the certainty of the evidence is low. The differences in sensitivity and specificity between the three index tests were not clinically significant. The three tests can be useful, with only a small difference in their diagnostic value. Histopathology was found not to be satisfactory as a reference standard.

Association of craniomaxillofacial fractures and blunt cerebrovascular injuries.

High energy trauma has been considered a risk factor for blunt cerebrovascular injuries (BCVI). The purpose of this study was to determine the incidence and risk factors for BCVI specifically in patients with maxillofacial fractures in an urban level I trauma center. A retrospective cohort study of patients aged ≥ 18 years, admitted to Massachusetts General Hospital (MGH) between 2007 and 2017, was implemented. There were 23,394 patients treated and entered into the MGH Trauma Registry: 22,287 sustained blunt trauma. Of the total blunt trauma patients, 68 (0.3%) had BCVI. There were 2421 patients with CMF fractures from blunt trauma (mean ± standard deviation age, 53 ± 22 years; 29.9% female included as study subjects, of whom 24 (1.0%) had BCVI). In a multivariate model, all mandible fracture (odds ratio (OR) 4.3, 95% confidence interval (CI) 1.6-11.6, P = 0.004), crush injury, defined as blunt compression injury (OR 11.1, 95% CI 2.1-58.1, P = 0.004), and cervical spine injury (OR 10.1, 95 CI 3.7-27.5, P < 0.001) were independent risk factors for BCVI. Mortality was 4.3 times higher in craniomaxillofacial fracture patients with BCVI versus those without BCVI; complications of BCVI (stroke) contributed to the majority of deaths. Appropriate screening and treatment of BCVI in patients with maxillofacial fractures is important.

Variables associated with stability after Le Fort I osteotomy for skeletal class III malocclusion.

The purpose of this study was to assess skeletal stability and predictors of relapse in patients undergoing an isolated Le Fort I osteotomy. A retrospective cohort study of 92 subjects undergoing Le Fort I osteotomy for Class III malocclusion was implemented. Predictor variables were demographic and perioperative factors. The primary outcome variable was postoperative skeletal position with relapse defined as >2mm sagittal and/or vertical change at A-point on serial lateral cephalograms at immediate postoperative, 1 year, and latest follow-up time points. Mean advancement at A-point was 6.28±2.63mm and mean lengthening was 0.92±1.76mm. Eight subjects (8.70%) had relapse (>2mm) in the sagittal plane, and two subjects (2.17%) in the vertical plane. No subjects required reoperation for relapse as overbite and overjet remained in an acceptable range due to dental compensation. In regression analysis, magnitude of maxillary advancement was an independent predictor of relapse in the sagittal plane (P=0.008). There were no significant predictors of relapse in the vertical plane. This study suggests that isolated Le Fort I osteotomy for correction of skeletal Class III malocclusion is a stable procedure and that greater advancement is an independent risk factor for sagittal relapse.

Regional differences in temporomandibular joint inflammation in patients with juvenile idiopathic arthritis: a dynamic post-contrast magnetic resonance imaging study.

The purpose was to determine whether there are regional differences in temporomandibular joint (TMJ) inflammation in patients with juvenile idiopathic arthritis (JIA). This was a retrospective study of all patients with dynamic, contrast-enhanced magnetic resonance imaging through the TMJs at Massachusetts General Hospital between January 2015 and July 2016. The patient cohort included those with a history of JIA and control patients who underwent MRI for other routine clinical purposes. TMJ inflammation was quantified as the difference between post-gadolinium and pre-gadolinium articular T1 signal intensity normalized to post-gadolinium signal intensity of the longus capitis muscle. TMJ enhancement profiles were generated for the lateral, central, and medial portions of the TMJ. Regional differences in TMJ enhancement were investigated using basic descriptive statistics. Medial edge enhancement of the TMJs was highest in symptomatic JIA joints, followed by asymptomatic JIA, then control joints. Medial edge enhancement was a significant discriminator between symptomatic JIA TMJs and control joints (P = 0.0001), between symptomatic and asymptomatic JIA TMJs (P = 0.0003), and between asymptomatic JIA TMJs and controls (P = 0.0019). A shift in distribution of TMJ enhancement towards the medial edge that was seen uniquely in both asymptomatic and symptomatic JIA TMJs compared to control joints was found. This suggests a pattern of worsening medial edge inflammation with disease.

Frequency of cervical spine injuries in patients with midface fractures.

The aim of this retrospective cohort study was to determine the frequency and risk factors for cervical spine injury (CSI) in patients with midface fractures. Patients ≥18 years of age entered in the Massachusetts General Hospital Trauma Registry from 2007 to 2017 were identified. Those with a midface fracture, computed tomography and/or magnetic resonance imaging of the cervical spine, and complete medical records were included. There were 23,394 patients in the registry; 3950 (16.9%) had craniomaxillofacial fractures and 1822 (7.8%) had a CSI. Craniomaxillofacial fractures included fractures of the midface (n=2803, 71.0%), mandible (n=873, 22.1%), and midface plus mandible (n=274, 6.9%). The overall frequency of CSI in patients with midface fractures was 11.4% (350/3077). Patients with midface fractures had a higher risk for CSI compared to patients without a midface fracture (odds ratio 2.4, 95% confidence interval 2.1-2.4, P<0.001). In a multivariate model, nasal and orbital fractures, chest injuries, age, injury severity score, and motor vehicle crash or fall as the etiology were independent risk factors for CSI. Mortality was two times higher in subjects with CSI. Early and accurate diagnosis of CSI is a critical factor when planning the treatment of patients with these fractures.

Optimization of Quantitative Dynamic Postgadolinium MRI Technique Using Normalized Ratios for the Evaluation of Temporomandibular Joint Synovitis in Patients with Juvenile Idiopathic Arthritis.

BACKGROUND AND PURPOSE: MR imaging has been shown to be useful in the diagnosis of juvenile idiopathic arthritis of the temporomandibular joint. Prior MR imaging approaches have relied mainly on the subjective interpretation of synovial enhancement as a marker for synovial inflammation. Although, more recently, several attempts have been made to quantify synovial enhancement, these methods have not taken into account the dynamic enhancement characteristics of the temporomandibular joint and the effect of sampling time. Our aim was to develop a clinically feasible, reproducible, dynamic, contrast-enhanced MR imaging technique for the quantitative assessment of temporomandibular joint synovitis in patients with juvenile idiopathic arthritis and to study the effect of sampling time on the evaluation of synovitis. MATERIALS AND METHODS: This was a retrospective study of all patients who had dynamic, contrast-enhanced coronal T1 3T MR imaging through the temporomandibular joint at our institution between January 1, 2015, and July 8, 2016. Patients in this cohort included those with a history of juvenile idiopathic arthritis and control patients who underwent MR imaging for other routine, clinical purposes. Synovial enhancement was calculated for each temporomandibular joint using 3 different types of equations termed normalization ratios. The enhancement profiles generated by each equation were studied to determine which provided the best discrimination between affected and unaffected joints, was the least susceptible to sampling errors, and was the most clinically feasible. RESULTS: A ratio of synovial enhancement (defined as the difference between the postgadolinium and the pregadolinium T1 signal of the synovium) to the postgadolinium signal of the longus capitis provided the best discrimination between affected and unaffected joints, the least susceptibility to sampling error, and was thought to be the most clinically feasible method of quantification of synovial inflammation. Additional synovial enhancement ratios studied did not provide the same level rates of discrimination between the affected and unaffected joints and were thought to be too temporally variable to provide reliable clinical use. CONCLUSIONS: We provide a robust, reproducible, dynamic gadolinium-enhanced MR imaging technique for the quantitative assessment of temporomandibular joint synovitis in patients with juvenile idiopathic arthritis.

Comparison of time required for traditional versus virtual orthognathic surgery treatment planning.

Virtual surgical planning (VSP) is a tool for predicting complex surgical movements in three dimensions and it may reduce preoperative laboratory time. A prospective study to compare the time required for standard preoperative planning versus VSP was conducted at Massachusetts General Hospital from January 2014 through January 2015. Workflow data for bimaxillary cases planned by both standard techniques and VSP were recorded in real time. Time spent was divided into three parts: (1) obtaining impressions, face-bow mounting, and model preparation; (2) occlusal analysis and modification, model surgery, and splint fabrication; (3) online VSP session. Average times were compared between standard treatment planning (sum of parts 1 and 2) and VSP (sum of parts 1 and 3). Of 41 bimaxillary cases included, 20 were simple (symmetric) and 21 were complex (asymmetry and segmental osteotomies). Average times for parts 1, 2, and 3 were 4.43, 3.01, and 0.67h, respectively. The average time required for standard treatment planning was 7.45h and for VSP was 5.10h, a 31% time reduction (P<0.001). By eliminating all or some components of part 1, time savings may increase to as much as 91%. This study indicates that in an academic setting, VSP reduces the time required for treatment planning of bimaxillary orthognathic surgery cases.

[Obstructive Sleep Apnea: review and a case presentation].

Obstructive sleep apnea may be a life threatening situation if does not get proper attention. Risk factors are easy to find, therefore general dental surgeons should be aware of them and refer if needed. This literature review clearly explains how obstructive sleep apnea is diagnosed and treated. We present a case of a patient with severe obstructive sleep apnea (apnea hypopnea index of 87.5/hour), who underwent bi jaw surgery with 2 piece Le Fort 1 maxiilary advancement, mandibular bilateral sagittal split osteotomy (BSSO) advancement, and genial tubercle advancement. Post-surgery sleep study demonstrated near resolution of previously severe obstructive sleep apnea with overall apnea hypopnea index (AHI) of 3.7/hour consistent with a successful surgical outcome.

Metastatic epithelioid angiosarcoma to the mandible: report of a case and review of the literature.

Angiosarcoma and its epithelioid variant are vascular malignancies that rarely affect the facial skeleton. Epithelioid angiosarcoma resembles carcinoma and can be difficult to diagnose. A case is presented of metastatic epithelioid angiosarcoma to the mandible from an angiosarcomatoid portion of renal carcinoma. The diagnostic challenge is outlined and the literature is reviewed.

Replication of ancient Egyptian osteotomies of the facial skeleton: insights into the mummification process.

A recent radiographic study of an Egyptian mummified head from the Middle Kingdom revealed methodical mutilations of the facial skeleton that were performed after death and prior to wrapping the corpse for burial. These mutilations consisted of removal of the coronoid processes of the mandible and portions of the zygomas presumably via an intraoral approach. They are unique in the archaeological record. The authors hypothesize that the procedures were carried out to facilitate jaw opening and may be related to a ritual known as the 'Opening of the Mouth' ceremony. The purpose of this study was to demonstrate the feasibility of performing these remarkable osteotomies on two human cadavers using instruments similar to those available to the ancient embalmer. Bilateral osteotomies of the zygomas and coronoid processes were carried out transorally and the bones removed. Pre- and postoperative maximal incisal opening measured 25 mm and 53 mm, respectively. Postoperative high-resolution computed tomographic (CT) scans were obtained. Comparison of the postoperative cadaver and mummy CT scans demonstrate remarkable similarity between the resections. Results of this study demonstrate that the ancient skeletal mutilations could have been performed transorally during the mummification process and would have enhanced jaw opening.

Influence of microparticle formulation on immunogenicity of SYI, a synthetic peptide derived from Streptococcus mutans GbpB.

Subcutaneous immunization with SYI, a peptide construct based on Streptococcus mutans glucan binding protein B (GbpB) residues 113-132, significantly reduces experimental dental caries. Since mucosal immunization may be preferred for human vaccine applications, the present objective was to determine what formulation of SYI combined with polylactide-coglycolide microparticles could give rise to significant levels of salivary IgA antibody reactive with the native GbpB protein. A comparison of the SYI construct, loaded into or mixed with polylactide-coglycolide revealed the SYI-loaded microparticles to induce significant and sustainable levels of salivary and nasal wash IgA antibody to the peptide and the native protein. SYI mixed with unloaded microparticles was less effective in mucosal antibody response induction. These studies indicate that mucosal immunization with the SYI construct can induce salivary IgA antibody to a pathogenesis-associated component of S. mutans if delivered within polylactide-coglycolide microparticles, suggesting that this approach could successfully induce protective salivary immunity to dental caries caused by S. mutans.