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Tumor eradication and esthetic and functional recovery of upper jaw defects are two of the greatest challenges in the treatment of an extensive maxillary tumor affecting the paranasal sinus. Here, we report a case of successful treatment of an advanced maxillary ameloblastoma extending to the maxillary and ethmoid sinuses and affecting the orbital floor. A 45-year-old man, who presented with a large mass in the left maxilla and a marked swelling of the cheek was referred to our department. He had a medical history of being given a diagnosis of ameloblastoma in the maxilla 13 years ago, but he had not undergone any treatment. Pre-operative radiographic examinations, CT, and MRI revealed a large tumor destroying the maxillary bone and extending into maxillary and ethmoid sinuses. The left nasal cavity was completely obstructed, and the bone of the orbital floor was lifted and deformed. After confirming the tumor as ameloblastoma, excision of the total left maxilla, palate, and orbital floor bone including the tumor extending to the nasal cavity and ethmoid sinus was carried out in joint surgery with an otolaryngologist. The surgical wound of the orbital floor and in the buccal area was covered by a forearm flap and skin graft in order to maintain a direct view of possible tumor recurrence near the skull base. Two years after the operation, there was no recurrence of the tumor. Disturbance of eyeball movement was not detected. Occlusal and speech functions were recovered using a maxillofacial prosthesis made by a prosthodontist. [ABSTRACT FROM AUTHOR]

Objective: The purpose of the present study was to elucidate the anatomic characteristics of the maxillary premolars for the planning of dental treatment using cone beam computed tomography (CBCT).Study Design: CBCT images were obtained for 150 maxillary premolars in 68 patients. The internal angle formed by the long axis of the maxillary premolars and the long axis of the alveolar bone was evaluated on the cross-sectional images. The vertical relationships between the maxillary premolars and the maxillary sinus were classified into 5 categories. The bone width and internal angle were compared among the images classified into the 5 categories.Results: The internal angle was 25.5 ± 6.9° at the maxillary first premolars. The incidence of Type I in the maxillary first premolars was 46.7%. In the maxillary second premolars, the incidence of Type I (14.7%) was significantly lower than the total incidence of Types II, III, IV, and V (85.3%). Type I had the significantly largest internal angle (28.0 ± 7.7°) among all types for the maxillary first premolars.Conclusion: When considering dental treatment in the maxillary premolars, one should observe the inclination of the maxillary premolars to the alveolar bone as well as the position of the inferior wall of the maxillary sinus. [ABSTRACT FROM AUTHOR]

Object The aim of this study was to assess our diagnosis system for cervical node metastasis for oral squamous carcinoma (OSCC) based on the combined results of computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US), and 18-fluorodeoxyglucose positron emission ( 18 F-FDG-PET/CT). Methods 106 patients with primary OSCC who underwent surgical treatment were divided into 3 groups. In group 1, cervical node metastasis was diagnosed by disunity combinations of diagnostic devices. In groups 2 and 3, it was assessed according to a set of diagnostic criteria that included the results of the CT/MRI, US and 18 F-FDG-PET/CT. In group 2, node status was considered negative when the results of both CT/MRI and US were negative. In group 3, node status was considered negative when the results of both CT/MRI and US were negative and the maximum standardized uptake value determined via 18 F-FDG-PET/CT was <3.2. Results 67 patients were diagnosed as cN0. 50 cN0 patients adopted the wait and watch policy, 12 of whom (24.0%) developed cervical node metastasis without recurrence at the primary site. Metastasis rates after surgery improved 33.3%, 23.5%, and 13.3% in groups 1, 2, and 3, respectively. In contrast, positive predict value (PPV) were worst (50.0%, 40.0% and 33.3%). Conclusions Our diagnosis system reduces the rate of cervical lymph node metastasis after surgery. [ABSTRACT FROM AUTHOR]

Objective: Various types of wound-healing dressings have been used to assist in the healing of surgical wounds. We analyzed the wound-healing process in an animal model using different existing wound dressings.Study Design: Full-thickness defects were created using a biopsy punch on the backs of 7-week-old rats. The wounded areas were covered with NEOVEIL (polyglycolic acid [PGA]) or TERUDERMIS (collagen sponge [CS]) affixed using a rat jacket. The wound area, neo-epithelium length, and α-smooth muscle actin (α-SMA) expression were evaluated and compared among the control, PGA, and CS groups.Results: The wound areas in the control group on days 4 and 7 were significantly smaller than those in the PGA and CS groups. The expression of α-SMA in granulation tissue peaked on day 4 for all groups. The expression of α-SMA in the control group on days 4 and 7 after injury was greater than in the PGA and CS groups. However, there was no significant difference in the expression of α-SMA between the PGA and CS groups.Conclusions: In this study, PGA and CS suppressed wound contracture and reduced expression of α-SMA in wound areas. However, PGA and CS did not affect the neo-epithelium length at the wound site. [ABSTRACT FROM AUTHOR]

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare odontogenic malignant tumor, and the origin is considered remnant odontogenic epithelium, odontogenic cyst, and rarely benign odontogenic tumors. We report an extremely rare case of PIOSCC arising from ameloblastoma. A 62-year-old man complained a large hard mass at the sublingual to the submental region. The computed tomography images revealed a large multilocular soft tissue mass extending into the bilateral molar areas with expansion of the mandible and also into the subcutaneous layer at the submental and the submandibular regions. He had received a curettage treatment of unicystic ameloblastoma in the right mandible 23 years ago. Malignant odontogenic tumor was suspected, and sectional mandibulectomy following reconstruction using a titanium plate and pedicle latissimus dorsi flap were performed. Histological examination disclosed a close correlation of intraosseous growth of squamous cell carcinoma and ameloblastoma. PIOSCC arising and dedifferentiated from long term existed ameloblastoma was mostly considered. There has been no recurrence and no metastasis for more than five years after the surgical treatment. [ABSTRACT FROM AUTHOR]

The fatigue of C/C composites was investigated in bending and shear modes. In bending, a large stress ratio resulted in a decrease in strength; the decrease became small without water present. However, a large ratio led to a decrease in Young''s modulus, regardless of the presence of water. In shear, degradation in strength or fatigue life decreased with increasing the ratio. For specimens fatigue degraded in air, static strength in water decreased as compared with that in air. It is strongly suggested that fatigue degradation in C/C composites is promoted by a combination of stress corrosion and crack propagation promoted by a wedge effect. [Copyright &y& Elsevier]