Comparison of the Pharyngeal Airway Volume Between Patients With Ectodermal Dysplasia and Unaffected Controls: A Cone-Beam Computed Tomography Study.

PURPOSE: Ectodermal dysplasias (EDs) are a diverse set of hereditary conditions in which 2 or more ectodermal structures develop abnormally. The purpose of this study was to use cone-beam computed tomography (CBCT) scans to measure the pharyngeal airway volume and minimum cross-sectional area (MC) among patients with ED and compare them with healthy controls. PATIENTS AND METHODS: The pretreatment CBCT scans of 9 individuals with ED and 61 controls were analyzed. Lateral cephalograms were created from the CBCT volumes and then traced and compared between the 2 groups. Airway volumes were evaluated by Dolphin 3D software (Dolphin Imaging, Chatsworth, CA) to compare the total pharyngeal volume, nasopharyngeal volume, oropharyngeal volume, hypopharyngeal volume, and MC. The mean airway volumes of the 2 groups were compared, and the odds ratio and relative risk of having an MC of less than 100 mm2 in the ED group were calculated. RESULTS: Intraclass correlation analysis showed excellent inter-rater reliability. All cephalometric features of controls were within the norms of patients with ideal skeletal-dental relationships. Patients with ED displayed significantly lower values for SNA (angle between sella-nasion and nasion-A point) (P = .018), ANB (angle between nasion-A point and nasion-B point) (P = .002), L1-MP (angle between long axis of mandibular incisor and gonion-menton plane) (P = .013), and L1-NB (distance between mandibular incisor and perpendicular line between nasion and B point) (P < .001). Although the ED group exhibited slightly smaller airway volumes for all subregions, the differences were not statistically significant for total pharyngeal volume, nasopharyngeal volume, oropharyngeal volume, hypopharyngeal volume, or MC (P > .05). The odds of having an MC of less than 100 mm2 were almost 3 times greater among ED patients, and the relative risk of an MC of less than 100 mm2 among ED patients was double that of controls. CONCLUSIONS: Although the craniofacial structures of individuals with ED are characterized by maxillary and midface deficiency, the airway volumes among affected individuals may not be significantly different from those of unaffected controls. However, patients with ED displayed a higher risk of having an MC of less than 100 mm2, which may be of clinical significance and warrants further investigations with larger samples.

Overexpression of dicer as a result of reduced let-7 MicroRNA levels contributes to increased cell proliferation of oral cancer cells.

Recent reports have demonstrated that Dicer, an RNase III endonuclease required for microRNA (miRNA) maturation, is aberrantly expressed in different types of cancer. Furthermore, Dicer has been reported to be regulated by the let-7 family of miRNA genes. We hypothesize that Dicer is aberrantly expressed in oral cancer cells due to altered expressions of let-7 and that Dicer contributes to the development and progression of the disease. Western blot examination of Dicer protein levels in four head and neck squamous cell carcinoma (HNSCC) cell lines, including two oral cancer cell lines, demonstrated that Dicer had between 4- and 24-fold higher expression levels when compared to normal human primary gingival epithelial cells. Furthermore, five of six oral cancer tissues analyzed by indirect immunofluorescence had increased Dicer protein expression, compared to normal gingival epithelial tissue. The Dicer mRNA levels were not found to correlate well with protein expression in the HNSCC cell lines, suggesting that Dicer protein expression was post-transcriptionally regulated. Analysis of let-7a and let-7b levels in HNSCC cell lines by real-time PCR demonstrated that let-7b, but not let-7a, was significantly reduced in the HNSCC cell lines compared to control cells. Lastly, transfection of oral cancer cells with chemically synthesized let-7b and small interfering RNAs targeting Dicer significantly inhibited cell proliferation up to 83% and >100%, respectively, as early as 3 days post-transfection. Together, these data demonstrate that elevated expression levels of Dicer in oral cancer cells correlate with downregulation of let-7b and increased cell proliferation.

TMJ arthroscopy in patients with Ehlers Danlos syndrome: case series.

OBJECTIVE: The purpose of this report was to assess the outcome of temporomandibular joint (TMJ) arthroscopy in patients with temporomandibular disorders (TMDs) associated with Ehlers Danlos syndrome (EDS). STUDY DESIGN: This retrospective case series describes 18 patients with EDS who underwent arthroscopy for temporomandibular disorders. The patients' demographics were recorded, along with preoperative TMJ symptoms, Wilkes classification, mouth opening, and the presence of systemic involvement. The incidence of early and late postoperative complications and the final outcome were noted. RESULTS: All of the patients were females, with EDS Type III, and had a mean age of 34 years. A high proportion of the patients had joints other than the TMJ affected. Five patients were classified as stage II according to the Wilkes classification, 9 patients were stage III, 3 patients were stage IV, and only 1 patient was diagnosed with stage V Wilkes before intervention. Arthroscopy, followed by arthrocentesis and balloon dilatation of the affected TMJs was performed and intra-articular morphine injections were given to all patients. The main pre- and early postoperative complaint was pain, but this resolved in most cases. Improvement of mouth opening was noted from 23.4 +/- 4.2 to 27.8 +/- 5.1 mm after arthroscopy. Patients were followed for an average of 62 months and all were asymptomatic at their last review appointment. CONCLUSION: For patients where conservative measures of treating TMD are not effective, arthroscopy is a minimally invasive surgical procedure that has been shown to result in a satisfactory outcome, with no need to resort to open joint surgery. This case series is limited by its size and further research on surgical intervention on EDS patients with temporomandibular disorders is recommended.

Risk factors associated with injury to the inferior alveolar and lingual nerves following third molar surgery-revisited.

OBJECTIVE: Earlier reports, including a preliminary study within our unit, have shown that the surgeon's experience is one of the most influential factors in determining the likelihood of both permanent inferior alveolar nerve (IAN) and lingual nerve (LN) paresthesia, following third molar surgery. The effect of this and other factors influencing such prevalence are assessed in this study. STUDY DESIGN: This prospective study involved 3236 patients who underwent surgical removal of impacted third molars. Patients' demographics and radiological parameters were recorded along with the grade of the treating surgeon. The prevalence of inferior alveolar and lingual nerves paresthesia at 1 month, 6 months, and 18 to 24 months postoperatively were also traced. RESULTS: At 1 month postoperatively, the incidence of IAN paresthesia was 1.5% and the LN was 1.8%. These figures decreased over time and 18 to 24 months postoperatively, the incidence of permanent dysfunction of the IAN was 0.6% and LN was 1.1%. With regard to inferior alveolar nerve paresthesia, risk factors included the patient's age (26-30 years), horizontally impacted teeth, close radiographic proximity to the inferior alveolar canal (IAC), and treatment by trainee surgeons. With regard to the lingual nerve, risk factors included male patients, distoangular impactions, close radiographic proximity to the IAC, and treatment by trainee surgeons. CONCLUSION: One of the main risk factors of developing permanent sensory dysfunction in the distribution of these nerves is related to the surgical skills/experience of the operator. Other factors are associated with the type of impaction and the radiographic proximity of the tooth to the inferior alveolar nerve. Such long-term complications can affect the patient's quality of life; the impact on profession, education, and research is unknown.