What Is a Safe Distance for Preservation of the Inferior Alveolar Nerve in Lower Gingival Squamous Cell Carcinoma? A Radiographic and Histopathological Study.

PURPOSE: Involvement of the inferior alveolar nerve (IAN) is important in the prognosis and treatment of gingival squamous cell carcinoma (SCC). METHODS: In this cross sectional study, patients with gingival SCC (T4a), undergoing hemimandibulectomy or subtotal hemimandibulectomy, were examined. The distance between the lesion and inferior alveolar canal (IAC) was measured, using axial computed tomography scans before resection. Following that, histopathological evaluation of IAN was conducted. The receiver operating characteristic curve was plotted to determine the association of IAN involvement in histopathological evaluation with various distances between the lesion and IAC. RESULTS: A total of 29 patients were examined in this study. The mean distance between the lesion and IAC was 9.40 ±â€Š2.21 mm. Nerve involvement was documented in 9 (45%) out of 20 males, while 11 (55%) men showed no involvement. Thirteen (44.82%) patients showed IAN involvement. The receiver operating characteristic curve demonstrated a cut-off point of 9.75 mm for the lesion-IAN distance. The possibility of IAN involvement was 23.33 times higher in patients who reported paresthesia, compared with patients without nerve involvement (odds ratio, 23.33; 95% CL; P = 0.001) CONCLUSION:: It seems that in a CT scan view, a 9.75-mm safe margin is associated with high accuracy for preserving IAN in patients with gingival SCC. Also, neurosensory disturbance can be considered a strong predictor of IAN involvement.

Comparison of Envelope and Modified Triangular Flaps on Incidence of Dry Socket after Surgical Removal of Impacted Mandibular Third Molars: A Double-blind, Split-mouth Study.

AIM: This study aimed to investigate the impact of modified triangular flap (MTF) compared with the envelope flap (EF) on the incidence of dry socket and healing degree after lower-impacted third molar surgery. MATERIALS AND METHODS: Present research was executed on 31 patients between the ages 17 and 24 years with the indication of removing impacted mandibular third molars in both sides with similar difficulty. The impacts of MTF and EF on degree of incidence of dry socket and healing on 3rd day and 1 week after surgery were recorded and investigated in a double-blinded manner. The significant changes in mentioned indices in two groups were statistically judged using Chi-squared and Wilcoxon's statistical tests. RESULTS: Three patients were excluded during the survey and 28 patients (56 samples) remained. The patients' average age was 20.1 years. Totally, 19 patients were female and 11 of them had academic education. Degree of dry socket incidence in MTF group was 11.76% and it was 41.17% in EF group (p = 0.042). In the follow-up session after 3 days since the surgery, healing degree mean in MTF group was 3.16 ± 1.5 and it was 4.37 ± 1.8 in EF group (p = 0.112). In follow-up session 7 days after the surgery, mean healing degree in MTF group was 0.037 ± 0.6 and it was 0.89 ± 0.73 in EF group (p = 0.005). CONCLUSION: Present study indicated that application of MTF may lead to a reduction in dry socket incidence and an increase of healing after 7 days since lower-impacted third molar surgeries. CLINICAL SIGNIFICANCE: Reducing postsurgery complication incidences following third molar surgery is an important issue, which could easily be achieved by designing appropriate flaps.