We studied maxillofacial fractures treated by departments of oral and maxillofacial surgery in Tokyo. A retrospective review of records and radiographs for patients admitted during the 5-year period from 2000 to 2004 was conducted at five departments in Tokyo. Date, age, gender, cause of injury, fracture site, concomitant injury, domestic violence against women, and treatment were reviewed. 674 patients with maxillofacial fractures were admitted. Male-to-female ratio was 3.6:1. The most frequent age group was 21-25 years. Fractures of the mandible were most frequent (87%), followed by the maxilla (14%) and the zygomatic bone (12%). Thirty-one percent of fractures were due to traffic accidents, 29% to accidental falls, 23% to violence and 14% to sports. The incidence of maxillofacial fractures caused by traffic accidents was lower, and that caused by falls and violence were higher than in other countries. Seventeen percent of the maxillofacial fracture patients had concomitant injuries. The incidence of domestic violence-related maxillofacial fracture was 1.6% of all cases. These cases were mainly caused by a husband (55%) or a sexual partner (36%). Most patients (67%) were treated by open reduction surgery. However, condylar fracture alone was usually treated by closed reduction surgery.

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Cyclin D1 gene (CCND1) numerical aberrations are independent prognostic indicators of head and neck squamous cell carcinomas (HNSCCs). High epidermal growth factor receptor gene (EGFR) copy number is associated with poor prognosis in lung cancer, but such findings are controversial in oral SCCs (OSCCs). We analyzed copy number status in CCND1 and EGFR in OSCC patients and its association with clinical outcome.
EGFR and CCND1 statuses were analyzed in 85 OSCC patients by fluorescence in situ hybridization (FISH) of specimens obtained by fine-needle aspiration biopsy.
CCND1 numerical aberration was found in 35 of 85 tumors (41%), and aberrant EGFR copy number was observed in 36 (42%). Gene amplification (GA) was dominant among CCND1 copy number changes (14/35:40%). Balanced trisomy (BT) was the most frequently observed EGFR aberration (17/36:47%). In a multivariate Cox's proportional hazards analysis, CCND1 GA was correlated with disease-free survival (P<0.001), whereas EGFR BT was significantly correlated with overall survival (P=0.001). Patients with a combination of CCND1 GA and/or EGFR BT had significantly poorer clinical outcome.
CCND1 and EGFR copy number changes were frequent in OSCC and had differing aberration patterns. CCND1 GA and EGFR BT statuses by dual-color FISH were the predominant predictors of clinical outcome. Further investigation is needed to determine the implications for EGFR inhibitor therapy in OSCC.

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The purpose of this study was to evaluate the influence of a bottled green tea beverage on dentin demineralization with a demineralization gel system in vitro. Samples were cut from bovine root dentin. Each sample was immersed in 8% methylcellulose gel onto which a layer of green tea beverage was placed. For comparison, sugar-free coffee beverage, deionized water, and 0.8-ppm F solutions were used. After two weeks, the treatment solutions were replaced with demineralization solution. The mineral profiles and mineral loss values of the lesions were obtained by transversal microradiography (TMR) after one-week demineralization. The green tea, coffee, and fluoride solution treatments induced a significantly thicker surface layer when compared with the deionized water treatment. In particular, the mineral volume % of the demineralized dentin specimens treated with green tea was approximately seven times higher than that of the de-ionized water treatment. The green tea treatment showed significantly lower mineral loss than the other three treatments. TMR measurements clearly showed that the sugar-free bottled green tea beverage inhibited dentin lesion progression, presumably due to the effect of sub-ppm fluoride levels.

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The objective of this study was to assess the possibility of developing a clinical minimally invasive and standardized method to evaluate the relationship between the microstructure of the jaw bone and systemic bone turnover. For this purpose, we performed standardized bone biopsy of the alveolar bone, and compared the 3D bone microstructure using micro-computed tomography (micro-CT) with bone mineral density (BMD) of the lumbar spine and biochemical markers of bone turnover. We evaluated a total of 9 samples taken from 6 patients by standardized biopsy using a trephine bur. BMD was evaluated using dual energy X-ray absorptiometry (DXA). Regarding the biochemical markers of bone turnover, serum bone-specific alkaline phosphatase (BAP) and serum osteocalcin (OC) were used as bone formation markers, and urinary cross-linked N-telopeptides of type I collagen (NTx) and urinary deoxypyridinoline (DPD) were selected as bone resorption markers. We scanned micro-CT images of these samples. Bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular spacing (Tb.Spac), fractal dimension, trabecular bone pattern factor (TBPf) and node-strut (Nd.Nd/TV, TSL/TV) were measured. Regarding the correlations between the parameters of bone microstructures, TB/TV, Tb.N, fractal dimension, and node-strut seemed to be positively correlated and Tb.Spac and TBPf seemed to be negatively correlated with each other, but Tb.Th seemed to have a low correlation with other parameters. OC and/or BAP showed a significantly high correlation with many structural parameters (p<0.05%). In conclusion, some microstructural parameters may change according to the systemic bone turnover.

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Palatalized articulation is one of the major articulation disorders which patients with cleft palate face after palatoplasty. Various causal factors have been suggested to date, but the main cause remains poorly understood. To clarify the possible causes of palatalized articulation in speakers with cleft palate, three-dimensional palatal morphology in patients with/without palatalized articulation in unilateral cleft lip and palate (UCLP) was analyzed.
Twelve UCLP patients with palatalized articulation (P group) and 20 UCLP patients with normal articulation (N group) participated in the present study. Speech was assessed in the two groups at the age of about four. Dental casts of the maxilla taken at the same time were analyzed three-dimensionally, and measurements in the horizontal, frontal, and sagittal planes were compared between patients with palatalized articulation and those with normal articulation. All dental casts were measured with a non-contact 3D laser scanner and the 3D data were analyzed with 3D-analyzing software.
Our study demonstrated three major findings of palatal morphology in UCLP patients with palatalized articulation when compared with their non-palatalized counterparts: 1) the posterior region of the palate was narrow in the horizontal plane, 2) asymmetry of the anterior palate was severe in the frontal plane, and 3) the palate was flat and shallow in the sagittal plane.
These findings suggested that palate deformities can affect the lingual-contact pattern, and may account for the backward movement of the articulation point.

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Microvascular free flap transfers have become a preferred reconstructive technique; however, rare complications may still prove devastating. This study reviewed 213 consecutive free-tissue transfers in order to assess the incidence and causes of complications in patients undergoing microvascular free flap reconstruction in the oral and maxillofacial region. In most cases, reconstruction was undertaken after resection of a malignant tumor. The flap donor sites were the radial forearm (n=111), rectus abdominis (n=88), scapula (n=13), and latissimus dorsi (n=1). The superior thyroid artery and the external jugular vein were commonly used as recipient vessels for anastomosis. The overall flap success rate was 99%. There were 7 cases of postoperative vascular thrombosis (6 venous and 1 arterial), constituting 3.3% of the entire series. Five flaps were salvaged, representing a 71.4% successful salvage rate in cases of vascular complications. Most of the successful salvage attempts were made within 24 hours of the end of the initial operation, and the successful salvage rate for re-exploration was 100%. Finally, the total flap loss rate was 0.9% and the partial flap loss rate was 2.3%. We conclude that early re-exploration should be the first choice for management of vascular compromised flaps. Complications at the donor site occurred in 17 cases (8.0%), the most common complication of which was partial skin graft loss after harvesting a radial forearm flap (n=10; 9.0%). Recipient and donor site morbidity was limited and considered acceptable.

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This study was intended to determine whether mouth-opening exercise reduces pain sensitivity in remote regions as well as in the trigeminal region. Seven female subjects with disk displacement with reduction were asked to perform a three-minute repetitive mouth opening and closing exercise (exercise A) and a three-minute continuous mouth opening exercise (exercise B) on two separate days. Sensory/nociceptive perception thresholds were measured at the point over the right masseter and the skin overlying the volar aspect of the right forearm immediately after exercises A and B, and were compared to data in which no exercise was performed (baseline). Significant elevation in the heat-induced pain threshold was seen as a result of both exercises in the cervical region and in the trigeminal region. Also, a significant elevation in the cold-induced pain threshold was seen after exercise B in the cervical region. Further, there was a tendency toward a higher warm sensation threshold after exercise A in the cervical region. These results indicate that mouth opening training produces non-segmental analgesic effects mediated by C fiber and A-delta fiber.

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