Correlation between the malignancy and prognosis of oral squamous cell carcinoma in the maximum standardized uptake value.

Positron emission tomography/computed tomography (PET/CT) examinations are indispensable in determining the stage, evaluating the treatment response, and diagnosing recurrence and metastasis during oral cancer treatment. In this study, we examined the correlation between the maximum standardized uptake value (SUVmax) for 18F-FDG PET/CT and the progressive factors, biological characteristics, and prognosis of oral cancer. We included 52 cases of oral squamous cell carcinoma with surgery as the initial treatment. Inclusion criteria included tumor diameter of ≥ 1 cm excluding superficial cancer. We performed 18F-FDG PET/CT examinations before surgery and determined the correlation between SUVmax and clinicopathological factors, such as histological grade, Ki-67 expression, as well as progress factors. SUVmax was significantly correlated with clinical T stage, vascular invasion, lymphatic invasion, Ki-67 expression, and postoperative event (recurrence or metastasis) in Student's t test. Using a cut-off SUVmax of 8.0, clinical T stage, lymph node metastasis, vascular invasion, infiltrative pattern, and Ki-67 expression significantly correlated in chi-squared test. Although observed and expected 3-year overall survival rates were not significantly different, observed and expected 3-year disease-free survival rates were significantly different. Analyzing each clinicopathological factor using various data obtained from 18F-FDG PET/CT scans may be useful to determine prognosis during oral cancer treatment.

Usefulness of Early Plate Removal in Patients With Occlusal Discrepancies After Sagittal Split Ramus Osteotomy.

The aim of this study was to evaluate the effects of early removal of fixed plates in patients with occlusal discrepancies after sagittal split ramus osteotomy (SSRO) with a focus on the positional relationship of the temporomandibular joint (TMJ). Sagittal split ramus osteotomy with/without Le Fort I osteotomy was performed on 98 patients with mandibular prognathism. Of these 98 patients, 15 with occlusal discrepancies and/or TMJ symptoms underwent early plate removal after SSRO. Finally, 12 consecutive patients were evaluated in this study: 7 underwent bilateral SSRO, 1 underwent unilateral SSRO, and 4 underwent bilateral SSRO with maxillary advancement. The axiolateral TMJ Schuller method was used to evaluate the TMJ position. The authors measured 3 spaces (anterior, superior, and posterior joint spaces) between the condyle and glenoid fossa in the sagittal plane. The anterior and superior joint spaces were significantly larger immediately after the operation than before the operation. After early plate removal, these spaces significantly decreased in size. The posterior joint space increased, but with no significant difference. Three months after SSRO, the size of each of the 3 spaces was closely related to its preoperative size. In conclusion, these results suggest that early removal of fixed plates is 1 treatment option for postoperative occlusal discrepancies after SSRO.

Toll-like receptor 2 activation implicated in oral squamous cell carcinoma development.

Recent studies have revealed that Toll-like receptors (TLRs) are highly expressed and activated in many types of cancer. Physiologically, TLR2 recognizes bacteria and other microorganisms in the oral cavity; however, the role of TLR2 in oral squamous cell carcinoma (OSCC) is unclear. In this study, we demonstrated that TLR2 is highly expressed in OSCC in comparison with adjacent non-malignant tissue. TLR2 was also expressed in OSCC-derived cell lines, and its expression was activated by ligands derived from bacteria and mycoplasma. Furthermore, to elucidate the mechanism of OSCC progression via TLR2 signal transduction, we focused on microRNAs (miRNAs) that are induced by TLR2 activation. Interestingly, ligand activation of TLR2 induced the expression of miR-146a and we found that downregulation of caspase recruitment domain-containing protein 10 (CARD10) mRNA in OSCC-derived cell lines. Moreover, knockdown of CARD10 induced resistance to cisplatin-induced apoptosis in OSCC cells. These findings suggest that the activation of TLR2 by bacterial components can enhance the progression of OSCC and may be implicated in acquired resistance to cisplatin-induced apoptosis through regulation of the miR-146a pathway.