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Oral carcinoma cuniculatum (CC) is defined as a rare variant of low-grade, well-differentiated squamous cell carcinoma (SCC). The diagnosis of oral CC has remained very difficult, due to the lack of familiarity of clinicians and pathologists with this pathology. Oral CC is therefore often initially diagnosed as osteomyelitis, dental abscess, or keratocyst. Histopathologically, oral CC is characterized by keratinized tissue lined by epithelium with no or only mild cellular atypia, which invades locally and rapidly into the bone. In the present case, oral CC developed from a state of leukoplakia. A white lesion on the lower gingiva was pathologically diagnosed as epithelial dysplasia without cellular atypia, but kept recurring after repeated local removal. Two years and nine months after the first visit, the lesion showed rapid invasion into alveolar bone, in which richly keratinized tissue was observed. The patient then underwent marginal mandibulectomy and the tumor was pathologically diagnosed as SCC. Based on the clinical follow-up, we suspected the lesion represented oral CC and wide resection with reconstructive surgery was performed. If oral CC can be diagnosed at an earlier stage, the area of resection can be minimized. As oral CC tends to be misdiagnosed because of a lack of evidence of malignant tumor, both clinicians and pathologists should consider oral CC when leukoplakia shows frequent recurrence.

Posterior disc displacement (PDD) is a rare temporomandibular joint disorder. PDD without reduction sometimes causes malocclusion. Splint therapy, arthrocentesis and manipulation are sometimes undertaken to reposition the disc in PDD without reduction. However, these treatment strategies are not always effective for chronic PDD without reduction. Here, we report a case of a 36-year-old Japanese male who presented with malocclusion with an anterior open bite. He was diagnosed with chronic PDD without reduction, and underwent a discectomy. His occlusion improved after surgery and became stable. This case suggests that a discectomy is an effective treatment option for malocclusion with anterior open bite caused by chronic PDD without reduction.

Adenosquamous carcinoma is a high-grade malignant tumor and is known to be more aggressive than conventional squamous cell carcinoma in the head and neck region. Initial precise diagnosis of ASC and consequent appropriate surgical resection of the primary lesion with neck dissections of regional lymph nodes is significantly important to achieve a good prognosis from ASC. Keywords: Adenosquamous carcinoma, Tongue, Differential diagnosis

The correction of deformities of the jaw in patients with facial asymmetry is challenging because of the high rate of relapse, which may partly be caused by skeletal interference and inappropriate seating of the condylar head. We evaluated outcomes in 30 patients who were treated by short lingual osteotomy with physiological positioning. Nine had facial symmetry (absolute displacement of the menton2mm), 14 had minor asymmetry (displacement of2 to4mm), and 7 severe asymmetry (displacement of4mm). The postoperative position of the menton (Me) was stable in each group, but deviated by 3.56mm in those with severe asymmetry. This deviation remained immediately after operation and after more than one year in this group, which implies that the Me was not on the mandibular midline. The lateral swing of both sides of the proximal segment did not change immediately after operation in any group. Although short lingual osteotomy with physiological positioning can result in skeletal stability, it is important to assess the association between the dental arch and the mandible using computed tomography to ensure a good outcome in patients with a skeletal class III deformity and facial asymmetry.

The present study was designed to investigate the physicochemical and bioactive properties of a nano-submicro sized octacalcium phosphate (OCP)-dispersed gelatin (Gel) composite (nano-submicro OCP/Gel) used as a bone substitute material in various bone defects. Well-grown, synthesized OCP was mechanically ground from 100 to 300 μm-sieved granules to particles that were approximately 500 nm in size. Then, 50 wt% of the nano-submicro OCP was mixed with porcine skin-derived acid extracted gelatin. The mixture was molded and lyophilized and then subjected to dehydrothermal crosslinking. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy showed that the structure of OCP was retained even after mechanical grinding to a nano-submicro scale level as well as inclusion in the Gel matrix. The bioactivity of nano-submicro OCP/Gel was examined by immersing the composite in simulated body fluid (SBF) for 7 days and by implanting it in rat critical-sized calvaria defects for 8 weeks. The nano-submicro OCP tended to convert to low crystalline hydroxyapatite (HA) in SBF as assessed by XRD. The nano-submicro OCP/Gel exhibited osteoconductivity in vivo, yielding new bone formation that was closely associated with the implanted composite. These results suggest that the nano-submicro OCP/Gel composite exhibits similar osteoconductivity as observed in other OCP-based materials previously reported and could be used as a bone substitute material for repairing various defects in bone.