Morio Tonogi

Investigation of environmental factors for diagnosing malignant potential in oral epithelial dysplasia

A study was conducted in rats with early tongue carcinoma induced by 4-nitroquinoline 1-oxide (4NQO), in order to investigate the early diagnosis of malignant potential of epithelial dysplasia. The rat tongue lesions were classified by their severity into three groups corresponding to early cancer, dysplasia and no change. The grade of epithelial changes was determined according to 13 items of WHO Epithelial Dysplasia Criteria. The expression levels of p53 and Bcl-2 proteins were detected immunohistochemically, and apoptotic cells were detected using the TUNEL method. In addition, a p53 mutation by lesions was detected. The expression ratio of p53 protein was high in dysplasia, and the ratio of Bcl-2 protein was high in early cancer and dysplasia. The TUNEL-positive cells were observed primarily in the granular layers of the no change cells, and their numbers decreased as the cells shifted to the early cancer stage. The p53 mutation was detected using a microdissection method in dysplasia, where it was found in three out of nine lesions. All the mutations in dysplasia detected were on the same codon that was found to be mutated in the early cancer. These results indicate that the association between the p53 mutation and histological changes in carcinogenesis epithelial dysplasia is strong, and that both the identification of p53- and Bcl-2-positive epithelium, and decrease in the TUNEL positive ratio, were useful for the diagnosis of the malignant potential of precancerous lesions.

Factors affecting independence in eating among elderly with Alzheimer's disease

Aim:  In elderly patients with dementia, disturbed eating behavior is understood to be a core symptom or a behavioral and psychological symptom of dementia (BPSD). The purpose of the present study was to investigate the factors affecting self‐feeding in elderly patients with Alzheimers disease (AD).

Carbon Ion Radiation Therapy Improves the Prognosis of Unresectable Adult Bone and Soft-Tissue Sarcoma of the Head and Neck

PURPOSE To evaluate the safety and efficacy of carbon ion radiotherapy (C-ion RT) with 70.4 GyE for unresectable bone and soft-tissue sarcoma of the adult head and neck. METHODS AND MATERIALS Twenty-seven patients (mean age, 46.2 years) were enrolled in this prospective study on C-ion RT with 70.4 GyE/16 fractions (fr) between April 2001 and February 2008. The primary end points were acute and late reactions of normal tissues, local control rate, and overall survival rate. The secondary end point was efficacy of the treatment in comparison to historical results with 57.6 or 64.0 GyE/16 fr. RESULTS The 3-year local control rate and overall survival rate for all patients were 91.8% (95% confidence interval [CI] = 81.0-100%) and 74.1% (95% CI = 57.5-90.6%), respectively. Acute reaction of Grade 3 or more was observed in only 1 patient. With regard to late reactions, visual loss was observed in 1 patient and a Grade 3 reaction of the maxillary bone was observed in 4 patients. A comparison with historical results revealed that the local control rate with 70.4 GyE was significantly higher than that with 57.6 or 64.0 GyE (3-year, 91.8% vs. 23.6%, p < 0.0001). Furthermore, the overall survival with 70.4 GyE tended to be higher than that with 57.6 or 64.0 GyE (3-year, 74.1% vs. 42.9%, p = 0.09). CONCLUSION C-ion RT with 70.4 GyE/16 fr for bone and soft-tissue sarcoma of the adult head and neck appears to be effective with acceptable toxicities in comparison to conventional RT and C-ion RT with lower doses.

Biomechanical three-dimensional finite-element analysis of maxillary prostheses with implants. Design of number and position of implants for maxillary prostheses after hemimaxillectomy.

The present study analyzed stress distributions in craniofacial structures around implant-supported maxillary prostheses. Using post-hemimaxillectomy computed tomography (CT) of a patient, the authors constructed a three-dimensional (3D) solid model using Digital Imaging and Communications in Medicine data (DICOM data) for maxillofacial and cranial bones. The effects of different prosthesis designs on stress distributions in craniofacial bones and osseous tissues around the implants were biomechanically investigated using 3D finite-element analysis. Maxillary prostheses were designed with 2 implants in the zygoma on the affected side and 2-3 implants in the maxillary alveolar bone on the unaffected side, without using a cantilever. Zygomatic implants provided suitable stress dispersal to the zygomatic and craniofacial bones on the affected side. This information is useful for designing maxillary prostheses.

Metastatic malignant ameloblastoma of the kidneys

Ameloblastoma is an uncommon disease in the urological field. The resulting tumors or cysts are of odontogenic epithelial origin, are usually benign in nature and rarely metastasize to distant organs. We describe a case of metastatic ameloblastic carcinoma in both kidneys of a 38‐year‐old Japanese man, who had a history of malignant ameloblastoma and was referred to us for evaluation because of gross hematuria and left flank pain. Computed tomography showed irregular cystic masses in both kidneys. After we confirmed that the primary lesion and the lung metastatic lesion had not recurred, we treated the patient surgically. Approximately 4 months postoperatively the patient suffered a local recurrence of tumors that was very invasive and aggressive. The patient died 2 months later and the autopsy showed local metastasis only, without any metastatic lesion in the lungs or other organs. The present case showed that malignant ameloblastoma is highly aggressive, and in the case of metastases the prognosis is usually extremely poor.

Expression of β-catenin in rat oral epithelial dysplasia induced by 4-nitroquinoline 1-oxide

The aim of this study was to evaluate whether β-catenin accumulation is useful for diagnosing the malignant potential of oral precancerous lesions. We investigated oral epithelial dysplasia adjacent to early cancer induced by 4-nitroquinoline 1-oxide in rats. Localization of β-catenin and cell proliferation were detected immunohistochemically, and exon 3 of the β-catenin gene was analyzed. Accumulation of β-catenin in the cytoplasm and nucleus was evident in 10 of 16 dysplasia lesions. Since almost all of the dysplastic lesions in these rats transformed to invasive cancer, β-catenin accumulation may contribute to the early stage of carcinogenesis. The Ki-67 labeling index was significantly higher in dysplasia and early cancer than in no change. However, there were no significant differences between the expression patterns of β-catenin protein, suggesting that other proliferation pathways are involved in the early stage of tumor development in addition to β-catenin accumulation. No mutations of exon 3 of the β-catenin gene were detected in any of the dysplasia or early cancer lesions. These findings suggested that β-catenin accumulation in the cytoplasm and nucleus without mutation of exon 3 is an early event during carcinogenesis in this tongue cancer model.

Effect of Maxillomandibular Advancement on Morphology of Velopharyngeal Space

PURPOSE The objectives of the present study were to assess the changes in upper airway morphology and function in response to advancement of the maxilla and mandible. PATIENTS AND METHODS Orthognathic surgery was performed. During the surgery, the maxilla and mandible were each advanced as a maxillomandibular advancement simulation. A total of 18 patients with a chief complaint of malocclusion were studied. The distance in jaw advancement and the anteroposterior and left-right diameters of the velopharyngeal space before and after jaw advancement were measured. After the anteroposterior and left-right dilation rates and area enlargement rates were calculated, we compared advancement of the maxilla with that of the mandible. RESULTS Each of the jaw advancements resulted in statistically significant increases in the anteroposterior and left-right diameters of the velopharyngeal space, and the area was significantly enlarged. The anteroposterior dilation rate was significantly greater after advancement of the maxilla, and the left-right dilation rate was significantly greater after advancement of the mandible. The velopharyngeal space area enlargement rate was significantly greater with advancement of the maxilla. CONCLUSIONS These data suggest that the mode of dilation of the velopharyngeal space differs between maxillary advancement and mandibular advancement. Jaw advancement affects the soft palate muscles, and the velopharyngeal space is expanded 3-dimensionally by each of those muscles. The difference in the pattern of expansion of the velopharyngeal space was related to differences in the functions of the soft palate muscles.

Histopathological characteristics of malignant melanoma affecting mucous membranes: a unifying concept of histogenesis

Aims: To investigate histopathological characteristics of melanocytic lesions affecting mucous membranes in various anatomical sites. Particular attention was paid to elucidation of morphological characteristics of early phases of mucosal melanoma in order to contribute to effective detection of this highly malignant neoplasm in the curable stages. Methods: A total of 87 melanocytic lesions of mucous membranes were investigated histopathologically. There were 55 malignant melanomas including eight lesions of melanoma in situ, three in the radial growth phase (RGP) and 44 in the vertical growth phase (VGP), and 28 benign melanocytic lesions including four melanotic macules, 19 melanocytic naevi and five blue naevi. In addition, this series also included four equivocal lesions for which diagnoses were not definitely determined. With regard to malignant melanoma, histopathological patterns of in situ phase and RGP were intensely evaluated. Results: Histopathological features of benign melanocytic lesions were essentially the same as those of the corresponding lesions of the skin. In the vast majority of mucosal melanomas, irrespective of anatomical sites, the main histopathological pattern seen in melanoma in situ and in RGP was the lentiginous pattern, which shows proliferation of atypical melanocytes in the lower layer of more or less acanthotic epithelium, though subtle variations of the pattern were detected. No association of melanocytic naevus was detected in any cases of melanoma. Based on these findings, we have proposed a unifying concept of de novo histogenesis of mucosal malignant melanoma. Conclusions: Our concept of histogenesis of mucosal melanoma assists in the identification of this highly malignant neoplasm in the early curable stages.

Factor analysis on oral health care for acute hospitalized patients in Japan

Aim:  We conducted a survey to investigate the status regarding the implementation of oral health care for inpatients aged 65 years and older who were in the acute stages of stroke and to examine the factors related to the details of excellent model hospitals.

Observation of the Internal Structure of the Zygomatic Bone by Micro-Computed Tomography

Abstract The purpose of this study was to use micro-computed tomography to investigate the internal structure of the zygomatic bone, and to evaluate the effects of biting force on the zygomatic bone by comparing the internal structure of this bone between dentulous and edentulous maxillae. In this study, 20 zygomatic bones of dentulous maxillae and 28 zygomatic bones of edentulous maxillae were used (mean age: dentulous maxillae, 72.6 years; edentulous maxillae, 79.6 years). Specimens were obtained from the skulls of cadavers, from the sutura frontozygomatica, posterior to the sutura temporo-zygomatica, down to the sutura zygomatico-maxillaris. From 2-dimensional slice images, we reconstructed the three-dimensional structure by volume rendering methods using micro-computed tomography. We used two anthropological reference points: jugale Ou) at the most concave point between the lateral margin of the upper zygomatic bone and the upper margin of the zygomatic arch ; and zygomaxillare (Zm) at the lowermost point of the zygomaticomaxillary suture. We examined the structure of the zygomatic bone at Ju, Zm and the mid-point between Ju and Zm. The dentulous maxillae had thicker trabeculae at these points than the edentulous maxillae. The thicker trabecular structure in the Ju area was especially pronounced in the dentulous maxillae. These findings indicate that stress from biting force influences the trabecular structure in the zygomatic bone. They also suggest that stress in the zygomatic bone is concentrated in the Ju area, because the masseter muscle and fascia temporalis adhere to the zygomatic bone.