Locoregional recurrence rate and disease-specific survival following marginal vs segmental resection for oral squamous cell carcinoma with mandibular bone invasion.

BACKGROUND AND OBJECTIVES: To determine locoregional recurrence rate (LRR) and disease-specific survival (DSS) following marginal vs segmental mandibulectomy. METHODS: Included were 210 patients, who had marginal or segmental mandibulectomy between 2000 and 2017. Marginal resection was performed when complete removal of the tumor was deemed feasible on the condition that at least 1 cm bone height of the inferior border of the mandible could be preserved. Segmental resection was performed in case less than 1 cm bone height of the mandible would remain. Clinical and histopathological data were collected from medical records. LRR and DSS were computed using Kaplan-Meier analysis. Cox-regression analysis was used to identify risk factors for LRR and DSS. RESULTS: A total of 59 marginal and 151 segmental resections had been performed. There was no significant difference in 3- and 5-year LRR (P = .904) and no significant difference in 3- and 5-year DSS (P = .362) between the marginal and segmental resection group. Cox-regression analysis showed a trend for surgical margin less than equal to 1 mm, to affect LRR (P = .05) and surgical margin less than equal 1 mm, perineural invasion and lymph node metastasis to affect DSS (P < .05). CONCLUSIONS: There was no difference in outcome between the two types of mandibulectomy.

Is the lingual fracture line influenced by the mandibular canal or the mylohyoid groove during a bilateral sagittal split osteotomy? A human cadaveric study.

PURPOSE: Although the bilateral sagittal split osteotomy (BSSO) is a routinely performed procedure, exact control of the lingual fracture line remains problematic. The purpose of this study was to determine the various lingual splitting patterns in cadaveric human mandibles after a BSSO and the possible influence of the mandibular canal and mylohyoid groove on the lingual fracture line. MATERIALS AND METHODS: The investigators designed and implemented a case series to compare different lingual fracture lines. A standardized SSO was performed on 40 cadaveric hemimandibles using elevators and splitting forceps. The primary outcome variable during this study was the lingual fracture pattern possibly influenced by independent variables: the mandibular canal, the mylohyoid groove, and dental status. Descriptive and analytic statistics were computed for each study variable. RESULTS: Most lingual fractures (72.5%) ended in the mandibular foramen. Only 25% of fractures were "true" Hunsuck fractures, and no "bad splits" occurred. In addition, 35% of lingual fractures ran more than halfway or entirely through the mandibular canal, whereas only 30% of fractures ran along the mylohyoid groove. However, when the lingual fracture ran along this groove, it had a 6-fold greater chance of ending in the mandibular foramen. CONCLUSIONS: The hypothesis that the mandibular canal or mylohyoid groove would function as the path of least resistance was only partly confirmed. The use of splitters and separators did not increase the incidence of bad splits compared with the literature.

Downregulation of SERPINB13 expression in head and neck squamous cell carcinomas associates with poor clinical outcome.

Tumorigenesis of head and neck squamous cell carcinomas (HNSCC) is associated with various genetic changes such as loss of heterozygosity (LOH) on human chromosome 18q21. This chromosomal region maps a gene cluster coding for a family of intracellular serine protease inhibitors (serpins), including SERPINB13. As SERPINB13 expression in HNSCC has recently been shown to be downregulated both at the mRNA and protein levels, here we investigated if such a low SERPINB13 expression is associated with histopathological and clinical parameters of HNSCC tumors and patient survival. By generating specific antibodies followed by immunohistochemistry on a well-defined cohort of 99 HNSCC of the oral cavity and oropharynx, SERPINB13 expression was found to be partially or totally downregulated in 75% of the HNSCC as compared with endogenous expression in non-neoplastic epithelial cells. Downregulation of SERPINB13 protein expression in HNSCC was significantly associated with the presence of LOH at the SERPINB13 gene in the tumors (p = 0.006), a poor differentiation grade of the tumors (p = 0.001), the presence of a lymph node metastasis (p = 0.012), and a decreased disease-free (p = 0.033) as well as overall (p = 0.018) survival of the patients. This is the first report demonstrating that downregulation of SERPINB13 protein expression in HNSCC is positively associated with poor clinical outcome. Therefore, SERPINB13 seems to act as an important protease inhibitor involved in the progression of HNSCC.