To investigate applicability of Ra needle interstitial brachytherapy, 93 cases of oral squamous carcinoma were examied. The patients underwent Ra needle interstitial brachytherapy as thorough therapy in our hospital. The criteria of applying Ra needle interstitial brachythrapy was diameter of within 5 cm and depth within 2 cm of tumor size. Ra needle interstitial brachytherapy was applied to 82 cases of tongue, 10 cases of oral floor and one case of lower lip carcinomas.
The local control rate was 92.5%, and secondary neck metastasis was 32.3% in all cases applied Ra needle interstitial brachytherapy. The results were not bad compared with surgical treatment. However, the 5-year cumulative survival rate was 64.9%, which was not good enough at the result to obtain a good local control rate and secondary neck metastasis rate. The result was relative to low treatment result of local recurrence cases with Ra needle interstitial brachytherapy. To improve the result, it is important of distinguish local recurrence from radioinduced ulcer, and to start early secondary treatment.
The cases in which cervical lymph node metastasis was found as the first examination underwent neck dessection after Ra needle interstitial brachytherapy. The 5-year cumulative survival rate was 83.3% in N1 cases and 40.6% in N2 cases, and the result of N2 cases was poorer than N1 cases with a significant difference.
The results indicate that a needle having a diameter of within 5 cm, depth of within 2 cm and less than N1 can be applied during Ra needle interstitial brachytherapy for complete cure of cancer.

View full abstract

The purpose of this study was to standardize the methods for evaluation of postoperative articulatory function. Japanese monosyllable intelligibility and conversation intelligibility were examined in 113 oral cancer patients, and patient's own assessment was also carried out by a questionnaire given to 74 patients. These three methods are relatively simple and easy and have been available for assessment of speech function.
1) Monosyllable intelligibility is variable, depending on the number of syllables. In case of moderate and severe speech disorders, the results of 25 syllables intelligibility test were considerably lower than those of 100 syllables. On the other hand, 67 syllables intelligibility tended to be slightly higher than those of 100 syllables in all degrees of disorder.
2) In case of mild disorder, the correlation between syllable intelligibility and conversation intelligibility was not significant. Conversation intelligibility with a finer scale is desirable in case of mild disorder.
3) Patient's own assessment (subjective evaluation) did not agree with conversation intelligibility (objective evaluation) . The patients had a tendency to underestimate their own speech function.

View full abstract

This study was conducted to investigate masticatory function of postoperative oral cancer patients via various methods to establish an appropriate for assessing functional states of the pateints.
Postoperative oral cancer patients, who had been treated at the First Department of Oral and Maxillofacial Surgery, Showa Dental Hospital, or Department of Oral and Maxillofacial Surgery, School of Medicine, University of Hannover, participated in this study along with controls: subjects with natural dentition and edentulous patients wearing conventional dentures, and non-tumor patients who had undergone implant therapy. Masticatory function was evaluated subjectively with a four-grade scale on masticatory satisfaction and Yamamoto's masticatory grade on diet. The balance of occlusal load and the area of occlusal contact were measured objectively with Occlusal Prescale. Chewing performance was also evaluated with the low-adhesive color-developing chewing gummethod. The relationship between subjective and objective methods were also investigated.
The results indicated that simulatneous evaluation with some subjective and objective methods, which coincided with the purpose and subjects of the study, reveals masticatory function of postoperative oral cancer patients appropriately.

View full abstract

Combined appropriate diagnosing techniques and optimal rehabilitation program are needed to obtain early improvement of dysphagia in postoperative oral cancer patients. This paper presents diagnosis techniques for dysphagia.

View full abstract

For reducing the postooperative dysfunction of oral cancer, an exact understanding of tumor malignant characteristics and its progression is necessary. Based on the above diagnoses, preoerative chemoradiotherapy has been actively performed on the patients with oral cancer with favorable clinical and histological results. In the treatment of oral cancer, especially for carcinoma of the maxilla, the use of maxillof acial prosthesis is necessary. The postoperative application of apatite implant may enable an early prosthetic reconstruction and the improvement of oral function and patient's QOL can be expected.

View full abstract

This study was conducted to investigate postoperative swallowing function, functional reconstructive method and a preventive aspiration method for defects of the tongue, floor of the mouth and oropharynx using free tissue transfer in 41 patients who had undergone resection of advanced oral cancer. The free tissue transfer used included 29 (71%) anterolateral or anteromedial thigh flaps, 5 radial forearm flaps, 5 rectus abdominis flaps and 2 fibula osteocutaneous flaps. The defect resulting from resection of half of the oral tongue or hemiglossectomy was reconstructed with a pliabel and large flap, such as an anterolateral thigh flap, a rectus abdominis flap or a radial forearm flap to preserve mobility of the residual tongue. Superior swallowing function was achieved in this surgical group. Defects following subtotal or total glossectomy were reconstructed with a large anterolateral thigh flap that was packed by a de-epithelialized proximal portion of the flap to provide bulk for the neotongue. Postoperatively, three of five patients who underwent this reconstruction experienced severe dysphagia. A reconstructive technique that provides bulk for the neotongue and counteracts the loss in tongue height is required. Further laryngeal suspension to prevent aspiration should be performed at the time of reconstruction.
Combined defects of the soft palate and oropharyngeal wall were reconstructed with an anterolateral thigh flap, the distal portion of which was made thinner for soft palate repair by the removal of fatty tissue. The de-epithelialized proximal portion was packed to provide bulk for the lateral wall. The reconstructed soft palate showed sufficient synchronized motion with the remaining soft palate. Good velopharyngeal closure and swallowing function were achieved with this reconstructive method.

View full abstract

From 1974 to 1998, reconstruction for defects of the mandible (123 cases) and maxilla (7 cases) was carried out at the First Department of Oral and Maxillof acial Surgery of Tsurumi University. The original disease of 72 of these cases was malignant tumor and that of the remaining 58 cases was benign tumor.
Three kinds of materials were used for reconstruction of bone defects. These consisted of 57 cases (60 operations) of non-vascularized bone grafts (58 iliac bones and two scapulae), 28 cases (30 operations) of porous hydroxylapatite (HAP) blocks and 45 vascularized bone grafts (41 iliac bones and 4 radial bones combined with forearm flaps) .
In 15 of the 26 malignant cases reconstructed by non-vascularized bone graft, major flaps were used to reconstruct soft tissue defects. In three of the 11 HAP block reconstruction cases, two PMMC-f laps and a rectus abdominal flap were used, and 29 of the 35 cases were reconstructed by vascularized bone grafts, five PMMC-f laps, 24 forearm flaps, and three groin flaps were used.
In more than half of the cases using vascularized and non-vascularized bone grafts, prosthodontic treatment was carried out and ten of them required dental implants. However, in cases using HAP blocks, prosthodontic treatment was performed in only one case.
The success rates of these three materials for reconstruction were 86.7% for non-vasularized bone grafts, 66.7% for HAP blocks, and 86.7% for vascularized bone grafts respectively.

View full abstract

Twenty-five implants were placed in 6 himimaxillectomy patients. After 11 to 79 months of follow-up, 2 of 25 implants were removed and 4 were buried. Sixty-seven implants were placed in vascularized bone grafts of 16 patients. After 9 to 69 months of follow-up, no implants were removed and 6 of 48 implants placed simultaneously with bone grafts were buried. In a multicenter study, 228 implants placed in irradiated tissues of 44 patients were evaluated. Of 228 implants, 59 were placed in the maxilla, and 169 were placed in the mandible.
Seventeen of 59 implants placed in the maxilla were removed ; and 3 of 169 were removed from the mandible.

View full abstract

The purpose of this study was to clarify the clinical and histopathological characteristics of oral leukoplakia and its malignant transformation and to delineate the clinical characteristics of early squamous cell carcinoma in order to diagnose oral squamous cell carcinoma in the early stage for a desirable outcome.
Four hundred forty-four patients with 601 oral leukoplakias were reviewed. 275 were males and 169 females. The ages ranged from 19 to 83 years. 25% of the 601 lesions were located on the mandible, 24.8% on the tongue, and 20.8% on the buccal mucosa. The lesions were classified into four clinical types, 76.2% into type I (leukoplakia without elevation nor red component), 14% into type II (leukoplakia with red component) . 4.8% into type III (slightly exophitic leukoplakia), and 5% into type N (markedly exophitic leukoplakia) . Malignant transformation rate (MTR) of type II was the highest (21.4%) type and that of the tongue was the highest (16.4%) of all the affected sites. MTR of female, older patients, and the lesions with epithelial dysplasia was higher than that of male, the younger under 50, and the lesions without epithelial dysplasia respectively. MTR after surgery was lower than that after any other treatment or no treatment.
Eighty-six patients with 88 early squamous cell carcinomas were examined and sixty-eight of 88 lesions were located on the tongue. As for the clinical type, 34.1% were classified into the mixed type and 21.6% into the leukoplakic and the granular types respectively. A ten-year cumulative survival rate of 86 patients was about 90%.

View full abstract

A pathological study was performed to investigate epithelial dysplasia, early cancer and early invasive carcinoma of tongue, gingiva, oral floor and buccal mucosa. The results were as follows
1. The expression of the cell proliferated relation marker was strongly observed in severe epithelial dysplasia, and in comparison with the early cancer and early invasive carcinoma, no significance was found.
2. The expression of cell function related marker was also strengthened in severe epithelial dysplasia, and in comparison with the early cancer and early invasive carcinoma, no significance was found.
3. In cell invasion marker, the expression of the matrix metallopretease (MMP) was also recognized in the normal epithelium, and by considering, adding and significantly strong expression in severe epithelial dysplasia compared to the normal epithelial cell, the expression of MMP was recognized in the connective tissue under the epithelium of epithelial dysplasia.
4. From the above results, promotion was begun, severe epithelial dysplasia even if it seemed to be the time at which the initiation had already ended in the stage of carcnogenesis, and even if the expression of MMP was observed ; and it was suggested to be the initial stage which starts the invasion into the connective tissue.

View full abstract

In an attempt to predict cervical lymph node metastasis of squamous cell carcinoma of the tongue, relationship between clinicopathological factors and metastasis in 280 patients was investigated by multivariate analysis (discriminate analysis the quantification theory type II) . In addition, expression of vascular endothelial growth factor (VEGF) and nm23H1-protein in 54 specimens of the primary tongue cancer was examined immunohistochemically in relation to metastasis.
Discriminate analysis showed that 4 factors such as the histopathological mode of invasion, the T category, the site of primary tumor (posterior, mid, and anterior) and the clinical type (elevated type, ulcerative type, granular type, and papillary or leukoplakic type) was significantly related to metastasis (p<0.05) . In the external check of discriminate analysis in 47 patients of stage I and II, 78.7% of the patients could be accurately distinguished for with and without late metastasis by a discriminate score (a total sum of the standardized scores of 4 factors) . Immunohistochemically, the frequency of metastasis was significantly higher (p<0.01), as the intensity of VEGF expression was increased. On the other hand, nm23-hl protein-positive group was apt to have a lower frequency of metastasis than the negative one (p<0.01) . The results suggested that this multivariate analysis using clincal and pathological findings, including immunohisochemical examination of VEGF or nm23-H1 protein, might be useful for predicting cervical lymph node metastasis and selsecting the therapeutic method for stage I and II of squamous cell carconoma of the tongue.

View full abstract

Oral squamous cell carcinomas (SCCs) correlating histopathologic findings with different clinical features were studied. Further, types of HPVs, p53 status, and EIAF expression in SCCs were investigated.
First the prevalence rate of HPV DNAs in normal oral mucosa was investigated. The nested PCR method was utilized to detect target DNA sequences using the HPV-E6/E7 consensus primer pairs. Of 56 patients examined, HPV-6 and HPV-16 DNA sequences were detected in a 46-year-old male and a 35-year-old female, respectively. Seventy-seven oral SCCs were examined to detect HPV DNAS by PCR and dot blot hybridization. HPV-16 DNA was detected in 23 cases of oral SCC and both HPV-16 and HPV-18 DNA were detected in one case of tongue SCC. HPV is one of the causative factors of oral squamous cell carcinomas.
The p53 status is very important for tumorigenesis and was examined by SSCP analysis and the yeast functional assay. Mutated p53 was detected in 30 % of oral SCCs by SSCP, while almost 80 % of oral SCC had been shown to be mutant p53 by the yeast functional assay.
EIAF is a newly-identified ets-oncogene family transcription factor. Previous reports have noted that EIAF can up-regulate promoter activities of several matrix metalloproteinase (MMP) genes and showed that invasive potentials of oral squamous cell carcinoma-derived cell lines are correlated with expression of EIAF and MMPs. Twenty-seven oral SCC specimens were examined using RT-PCR. Southern blot hybridization and in situ hybridization (ISH) and compared to the clinico-pathological parameters. Among the 27 patients, E1AF was detected in 15 cases. E1AF mRNA was detected in 13 of 17 invasive SCCs, whereas the majority of SCCs not expressing EIAF showed an expansive growth pattern. Increased prevalence of EIAF-positive oral SCC was observed in cases with nodal metastasis. The results indicate that EIAF may be involved in cancer cell malignancies through its ability to promote invasive potential.

View full abstract

Squamous cell carcinomas generally show close morphological similarities to each other, but different features vary in prominence according to the degree of differentiation. Ultrastructure of different oral SCC types has been reported by a number of authors. The results of ultrastructural studies of oral squamous cell carcinoma (SCC) have provided a clearer understanding of the differences between well-differentiated and poorly-differentiated SCCs.
Disturbances in growth, including the carcinogenesis, are often linked with an increased rate of cell proliferation. Over the past few decades, there has been considerable interest in markers of cell proliferation that can be used as indicators of the histopathological grade and the tumor behavior of human cancers. The number of mitoses per high-power field is one of the morphological features used to grade oral SCC. Many studies utilizing immunohistochemical markers of cell cycle antigens, including PCNA and Ki-67, to derive a labeling index in oral carcinomas have been reported. These immunohistochemical methods are now widely accepted. The significance of prolif erative activity depends on the number of cells undergoing apoptosis. Disordered balance between proliferation and apoptosis may contribute to carcinogenesis. Bcl-2 has been shown to antagonize the cell death pathway. Overexpression of bcl-2 has been reported in a number of oral SCCs. p53 is also a key gene involved in human malignancies. p53 is known to be a tumor suppressor gene and can induce apoptosis of unnecessary cells. The avoidance of apoptosis by the mutation of the p53 can contribute to the development of a malignant tumor. Many studies have examined the relationship of overexpression of p53 protein with the statee of cell proliferation in oral carcinomas.
This review focuses on the relationship between the histopathological grade and the characteristics of SCC, which include the ultrastructural features, cell proliferation, and apoptosis-related genes.

View full abstract