Plumbagin suppresses tumor cell growth in oral squamous cell carcinoma cell lines.

OBJECTIVES: Plumbagin (PL), a naturally occurring quinoid, exerts antitumoral effects in diverse types of cancer cells. However, the effect of PL on tumor cell proliferation in oral squamous cell carcinoma (OSCC) remains poorly understood. In this study, we assessed the efficacy of PL, in human OSCC cells. METHODS: The effect of PL on the cell growth and apoptosis of OSCC cell lines was evaluated using MTT and Annexin V assays, respectively. The effect of PL on mitochondrial membrane potential loss and reactive oxygen species (ROS) generation was evaluated using flow cytometry analysis. RESULTS: MTT assay showed that PL dose-dependently suppressed OSCC cell growth, with IC50 values ranging from 3.87 to 14.6 µM. Flow cytometry analysis revealed that PL treatment resulted in a significant decrease in mitochondrial membrane potential and an increase in the number of apoptotic cells. Notably, ROS generation was significantly elevated after PL treatment. Furthermore, a ROS scavenger, N-acetylcysteine (NAC), clearly suppressed the decrease in mitochondrial membrane potential, increase of caspase-3/7 activity, and apoptosis after PL treatment. CONCLUSION: This study provides the considerable evidence of the tumor-suppressive effect of PL, thereby highlighting its therapeutic potential for OSCC treatment.

Effective three-dimensional evaluation analysis of upper airway form during oral appliance therapy in patients with obstructive sleep apnoea.

The oral appliance (OA) is considered to be an effective treatment modality for obstructive sleep apnoea (OSA). Upper airway enlargement during OA therapy is critical, and lateral cephalometry has been used for the two-dimensional evaluation of upper airway form during this therapy. However, this method cannot provide an accurate three-dimensional (3D) view of upper airway form. To confirm the effects of OA on the upper airway in patients with OSAS, we performed CT in the presence and absence of OA in 15 Japanese patients (12 males, 3 females) who responded to OA therapy. CT in the presence and absence of OA was consecutively performed for each patient, and upper airway cross-sectional area in six arbitrary planes parallel to the palatal plane was measured. Next, 3D image reconstruction was performed; morphological changes in upper airway form were evaluated, and upper airway volume at three levels from the palatal plane to the deepest point of the epiglottis was measured. The cross-sectional area of two planes in the posterior soft palate region significantly increased in the presence of OA compared with that in the absence of OA. In the presence of OA, upper airway cross-sectional area and volume significantly increased in the posterior soft palate region compared with those in the posterior tongue region. 3D CT image reconstruction accurately confirmed morphological changes in the upper airway during OA therapy. Continued use of this 3D evaluation is expected to improve the results of OA therapy in the future.

Functional reconstruction after a total maxillectomy using a fibula osteocutaneous flap with osseointegrated implants.

The fibula osteocutaneous flap with osseointegrated implants was used for reconstruction of a total maxillectomy defect. We have achieved satisfactory reconstruction of three-dimensional facial structure, orbit support, and a functional prosthesis. Our procedure restored the patient's masticatory function of the maxilla and enabled good speech and a natural facial appearance. A very high quality of function was obtained without any complications, but long-term follow-up is necessary for maintenance of the implants.