Second-Degree Atrioventricular Block Occurring After Tooth Extraction.

Although cardiac arrhythmias are occasionally associated with dental extractions and dental anesthesia, atrioventricular block is rarely seen during dental procedures. We report a rare case of type I second-degree atrioventricular block (Wenckebach phenomenon) occurring after bilateral extraction of impacted mandibular third molars under general anesthesia in a 16-year-old Japanese girl. Under consultation with a cardiovascular physician, we carefully monitored the patient's vital signs postoperatively, including blood pressure, oxygen saturation, and electrocardiogram, using a bedside monitor. Her postoperative course was uneventful. A 12-lead electrocardiogram the following day revealed no abnormality. In this case, we hypothesize that extubation of the nasotracheal tube or oral/pharyngeal suction might have triggered a vagal reflex that caused type I second-degree atrioventricular block. Our experience indicates that standard cardiovascular monitoring should be used for patients undergoing dental treatment under general anesthesia, even for young, healthy patients, to prevent and detect cardiovascular emergencies.

Clinicopathological implications of vascular endothelial growth factor 165b expression in oral squamous cell carcinoma stroma.

Vascular endothelial growth factor (VEGF) is one of the most important angiogenic factors. VEGF165b was recently isolated as the anti-angiogenic VEGF splice variant. In the present study, we examined the association between VEGF165b expression and clinicopathological characteristics in order to determine how VEGF165b produced from oral squamous cell carcinoma (OSCC) affects the stromal cell biological activity. We examined the relationships between the expressions of both VEGF isoforms in normal human dermal fibroblasts (NHDFs) and OSCC cell lines (HSC2, 3, 4 and SAS). Our analyses indicated that both the mRNA and protein expression levels of VEGF165b in the HSC2 and SAS cells were higher than those in the NHDFs. VEGF165b did not promote cell growth or invasive capabilities, but it induced the cell adhesive capabilities to ECM. Although strong expression of the VEGF165 isoforms in tumor cells of OSCC tissues was observed, there was no significant difference in the VEGF165b expression level among the various degrees of malignancy. OSCC cells secrete VEGF165b into the stroma, and this factor may contribute to the process of anti-angiogenesis by inhibiting gelatinase-expressing cells and activating cell adhesive capabilities to ECM, such as that of fibroblasts surrounding tumor cells.

Myositis ossificans traumatica of the masticatory muscles.

Myositis ossificans traumatica (MOT) is a disease in which muscular ossification develops following trauma. Almost all cases of MOT are found in skeletal muscle. The authors report in a 39-year-old man MOT involving several muscles in the head and neck, namely, bilateral masseter muscles, the left temporal muscle, the left lateral pterygoid muscle, and the left frontal muscle. Involvement of the lateral pterygoid muscle is especially rare.