The main purpose of this study was to experimentally classify the histogenesis and malignant course of gingival carcinoma, showing its relationship to the clinical progress of chronic periodontitis. The experiment was performed using an oral cancer model induced by the oral administration of 4 NQO solution. Seventy S-D rats were given administered with a 0.001% 4 NQO solution for 34 weeks. Ten rats were prepared as controls. Fifty-seven rats were killed with ether at intervals between 30 and 75 weeks after the beginning of administration of 4 NQO, and the gingiva was histologically examined at the first and second molars, and at the retromolar area in both maxilla and mandible. The incidence of gingival carcinoma was relatively high; 80% between 60-64 weeks. All carcinomas induced were of the squamous cell type. Carcinogenesis in the gingiva was observed in the junctional and differentiation and gingival epithelium. Histogenesis in the junctional epithelium was also discernable parthy as a result of malignant processes in the inner epithelium; particularly by malignant changes localized in the junctional epithelium, slight dysplasia of the gingival oral epithelium, and the maintenance of on obvious border between junctional and gingival epithelium. Malignant changes in the junctional epithelium, combined with extension of epithelium in to the cementum, exfoliation of epithelium and retraction away from the enamel by dysplastic changes all resulted in the formation of a gingival pocket. Finally, invasion of the periodontium by cancer nests resulted in the so-called “floating tooth” Carcinogenesis in the junctional epithelium may indicate the histogenesis of human gingival carcinoma, whilst appearing clinically to follow the course of chronic periodontitis. It is considered that formation of gingival pockets by malignant changes of junctional epithelium further indicate the clinical charactristics of gingival carcinoma of this type. Malignant processes in junctional epithelium by replacement of epithelium by atypical cells indicates “epithelial dysplasia-carcinoma in situ-early invasive carcinoma”. In the gingival epithelium, the malignant processes showed “epithelial dysplasia-early invasive carcinoma” by atypical downward proliferation of epithelium.
To elucidate the effect of long-term intake of ethanol on the parotid gland, observations of parotid glands from male Wistar Strain rats given 20% ethanol ad lib. instead of water were performed, using light and electron microscopy. Results were as follows:(1) Under the light microscope, 3 rats (11%) demonstrated several lesions involving complete lobular units, and (2) under the electron microscope, the earliest and most consistent changes after ethanol intake were the irregular formation of microvilli and interdigitation between parenchymal cells. These were accompanied by widening of the intercellular spaces and disappearance of the basal infolding structure with severe mitochondrial alteration in striated duct cells. Tortous proliferation of intercalated duct cells was observed after 4 months of ethanol intake. These results suggest that the intake of ethanol leads to injury of the inter-parenchymal cell membranes and to the basal membranes of striated duct cells. Repeated degeneration and regeneration of duct cells during the repair process results in deformation of ductal structure at the level of the intercalated ducts, followed by the degeneration and subsequent atrophy of the acini.
Many dental implant materials used clinically have been subject to basic investigation. Recently, bioceramics have become the main materials used in dental implantation. This study notes that SiC is a non-hydrated material exhibiting superior hardness and lower weight. We have compared SiC with ZrO2 in terms of cytotoxicity. And this is a comparative study with ZrO2 in cytotoxity test and compatibility with soft tissue and bone. The results were as follows. 1) Amount of dissolved Zr4+and Si4+ ions were below 1.0 ppm. 2) Cytotoxity was the same as that of ZrO2 and glass, examined by the colony formation method, investigation of cell growth and SEM findings of the cell forms on the materials. 3) SiC exhibited the same biocompatibility as ZrO2, as demonstrated by light and electron microscopic examination of subcutaneous implantation in the rats and femurs marrow space implantation in the rabbit. Results suggest that SiC is not cytotoxic and exhibits biocompatibility equal to that of ZrO2. The author therefore feels able to recommend the clinical use of SiC as soon as possible.
Several recent studies suggest that the demonstration of ras p 21 may serve as el useful marker of tumor proliferation and in the prognosis of the malignant patient.In this study, immunohistochemical investigation was performed to elucidate possible correlations between ras p 21 products and disease prognosis, and/or other factors. Demonstration of ras p 21 products in 48 oral squamous cell carcinomas and 15 benign lesions was investigated using a monoclonal anti-ras p 21 antibody in the avidin-biotinperoxidase complex method. Immunohistochemical demonstration of ras p 21 products was observed in 54.2%(26/48) of squamous cell carcinomas and in 20%(3/15) of benign lesions.Demonstration of ras p 21 products bore no correlation with clinical stage, incidence of lymph node metastasis or recurrence rate. They were, however demonstrated in 67.6%(25/37) of differentiated squamous cell carcinomas, but in only 9.1%(1/11) of poorly differentiated cancers. These results suggest that demonstration of ras p 21 products cannot be considered a reliable marker of malignancy and that ras p 21 is associated with cellular differentiation rather than cell proliferation.
The effect of unilateral duct ligation on submandibular salivary glands was studied by autoradiography, angiography and the radioactive microsphere technique. A. Ligated side: After several days, ligation of the main secretory duct led to acute atrophy, degeneration and tissue necrosis; fibroblast and adenoepithelial prolifecation was noted in this region and labelled with 3H-thymidine. Blood vessels were dilated and congested, and blood flow was found to be increased. At 14 days, glandular regeneration and blood flow levels were found to have decreased to about 85% of normal. B. Non-ligated side: No pathological changes were noted. At 2-3 days, acinar cells were labelled with 3Hthymidine; blood vessels were found to be dilated blood flow increased.
An in vitro model designed for studying the mechanism of oral squamous cell carcinomas invasion was developed using a specific culture matrix composed of a collagen gel combined with human fibroblasts. Five SCC cell lines cultured on collagen-only gels showed stratified growth. However, all five cell lines demonstrated invasion into the matrix when cultured on the fibroblast-incorporating collagen gels. Moreover, fibroblastconditioned medium was shown to promote the invasion of HSC-3 cells into the collagen gels. HSC-3 cells were examined for their ability to degrade collagen gels. HSC-3 cells showed enhanced matrix degradation when cultured on [3H]-labeled collagen gels with fibroblast feeder layers. These results suggest that fibroblasts may play an important role in the invasion of oral SCC cell lines in vitro. Four cell lines newly established in our laboratory were tested in this assay system. These cell lines cultured on fibroblast-incorporating collagen gels expressed morphologic and biologic characteristics in vitro similar to those in vivo. This assay system therefore proved a reliable and sensitive model for analysis of the invasive behaviour of human SCC cells. The system also demonstrates potential as a guide to prognosis and treatment in the evaluation of oral cancer.
Hypertrophy of the masseter muscle is relatively uncommon. Legg described this condition in 1880, about 130 cases have been reported since then. The authors have recently experienced three cases of masseter hypertrophy. Case 1 was 17-year-old man whose chief complaint was bulging at the right angle of the mandible during forceful occlusion. Case 2 was a 44-year-old man with large swelling of the left cheek. Case 3 was a 20-year-old man with swelling at the left angle of the mandible. CT proved effective in diagnosis All three cases presented with asymmetry of the face and were treated surgically. Asymmetry of the face was objectively evaluated both pre-and post-operatively by CT imaging and P-A cephalometric radiography. Results of surgical correction were satisfactory.
Osteosarcoma is second only to multiple myeroma in the incidence of tumours of bone, but its occurrence in the mandible is relatively rare. This article reports on two cases of osteosarcoma in the mandible. Case 1: A 47-year-old female complained of paresthesia of the right mental region. Osteomyelitis of the mandible was suspected on clinical examination. After extraction of the lower right second molar, the right molar region of the mandible rapidly swelled and tumorous tissue developed in the tooth socket. Radiation therapy was chosen since malignant lymphoma was suspected based on histopathological findings, but the swelling increased. On histopathological re-examination, a diagnosis of osteosarcoma was established. Although high dose methotrexate (MTX)-citrovorum factor (CF) therapy was instituted (100-200 mg/kg) after radical surgery the patient died of pneumonia resulting from lung metastasis. Case 2: A 48-year-old male complained of swelling in the right molar region of the mandible. Examination revealed tumorous tissue with sequestration in the molar region. Based on histologic examination, a diagnosis of fibroosseous lesion was made. Marginal resection of the mandible was performed, but local recurrence was noted 6 months later. Histologic examination of the second biopsy was negative for malignancy, and segmental resection was performed. However, swelling of the mandible recurred soon after the 2nd operation. The patient underwent further surgery, and a final diagnosis of osteosarcoma was reached. High dose MTX-CF therapy was instituted soon after surgery. There has been no sign of recurrence or metastasis in the 2 years since the 3 rd operation.
Dermoid cyst and epidermoid cyst generally occur in the anal region and ovary, and occurrence in the oral region is relatively rare. The authors reported in the literature a case of large epidermoid cyst in the floor of the mouth. The patient, a 55-year-old man, noticed a mass in the floor of the mouth during childhood. The mass gradually enlarged. At the initial consultation he complained of motor disturbance of the tongue and speech difficulties. Using general nasoendotracheal anesthesia, the mass, which had invaded the submental region through the mylohyoid muscle, was extirpated by the intra-oral method. The specimen measured, 8×6×3.5 cm, was ovoid shaped and weighed 120g. Microscopically, the cystic wall was found to be composed of keratinized squamous epithelium and connective tissue, but did not contain skin inclusions. Based on histological findings, a diagnosis of epidermoid cyst was established.
The cementifying fibroma is a rare benign fibro-osseouse lesion of the jaw, and is generally believed to originate from the periodontal ligament, which possesses the capacity to form cementum, and alveolar bone and fibrous tissues. We present a case of central cementifying fibroma with an impacted tooth in the mandible. The patient was a 28-year-old woman who, since age 15, had noticed diffuse swelling in the region of the right mandible. Multiple angle radiography and CT scanning demonstrated well-defined radiolucent area on the right side of the body of the mandible, exhibiting sharply circumscribed borders and containing irregular radiopaque areas and an impacted tooth. The tumor was completely excised by a segmental mandiblectomy as lower cortical bone was found to be resorped. Immediate reconstruction was undertaken using an aluminaceramic mandibular prosthesis. Microscopic examination of the tumor revealed a spindle cell stroma containing collagen fibers surrounding various-sized islands of hard cementum-like tissue. Based on these findings a diagnosis of cementifying fibroma was reached.
A case of basal cell nevus syndrome is reported. The patient, a 25-year-old man, had no family history of this condition. The patient showed multiple mandibular cysts, calcification of the falx cerebri, bridging of the sella turcica, ocular hypertelorimsm, a broad nasal root, and pitting of the palms. These findings correlate with reports in the literature and permitted the diagnosis of basal cell nevus syndrome.
A case of carcinoma in pleomorphic adenoma which developed in the deep lobe of the left parotid gland of a 75-year-old Japanese man is described. The case was clinically prediagnosed as a benign salivary gland tumor; however, examination of excised tissue revealed small areas of adenoid cystic carcinoma invading the capsule and of pleomorphic adenoma comprising almost all the tumor tissue. The surgical procedure choice included complete excision of the tumor tissue with lobectomy of the superficial part of the left parotid gland. Recurrence or metastasis has not been noted in the one year and 8 months since operation. The excised material was also examined from an immunohistochemical aspect, using the peroxidase-antiperoxidase method. The staining of S-100 protein, lysozyme, transferrin, secretary component, and keratin showed similar findings as have been already reported.
Pleomorphic adenoma occurs most frequently at the parotid gland in the major salivary gland and at the palate in the minor salivary gland. Reports of pleomorphic adenoma in the lip and the buccal mucosa are rare. Two cases of pleomorphic adenoma considered to have originated at the lip and the buccal mucosa are presented. The first was a 52-year-old male in whom tumor occurred in the upper lip. The second was a 43-year-old female with a tumor in the right buccal mucosa. The tumors were surgically removed and on pathological investigation were diagnosed as pleomorphic adenoma case. No recurrence has been reported in either.
In the past 6 years, from 1982 to 1987, 24 patients received reconstructive surgery using various pedicle flaps for oral and maxillofacial defects. Various flaps were utilized for reconstruction: 14 deltopectoral 5 pectoralis major myocutaneous and 2 forehead flaps for larger defects; and 7 cervical island skin and 4 sternocleidomastoid flaps for moderate defects. As to results, most of the flaps used for the repair of soft tissue enabled sufficient recovery of shape to satisfy these patients. However, recovery of speech and mastication function was not always reliable with these flaps, especially after reconstruction for defects of tongue or gum for which mandibular reconstruction was performed. In this report, some problems which should be considered in oral and maxillofacial defect reconstruction are discussed.
Methods of mandibular reconstruction using an intact portion of the ascending ramus are described. The patient was a 71-year-old male, diagnosed as having gingival carcinoma in the left lower molor region. Preoperative radiation therapy with 60Co (total dose 36 Gy) was administered. Osteoectomy from the first premolar to the region of the angle was performed to enable single piece resection of the tumor. Under direct observation the bone necessary for reconstruction, about 5-1cm size, was separated from the resected segment of mandible. The mandible was then reconstructed by bridging the gap with the autogenous bone. No clinical evidence for tumor recurrence was found at 12 months. Although the patient's left cheek developed a slight depression, occlusion was satisfactory. We therefore feel the method reported is useful for immediate mandibular reconstruction after lower molar excision, providing that the excision does not exceed 5cm in length.
Good progress has recently been reported in the reconstruction of the mandible after resection in the treatment of tumors. However, younger patients undergoing resection during the period of growth are left with many problems, both esthetic and functional. Good results were obtained in the successful restoration of severe disorders. Correction of occlusal malfunction and esthetic improvement were obtained with reconstruction of the mandible by osteotomy and bone graft after the cessation of mandibular growth. A 13-year-old patient underwent mandibular resection from the premolar area to the condyle and dissection of the upper right neck in the treatment of ameoblastic fibrosarcoma. Reconstruction using fresh autogenous iliac bone was performed at 18 years. However post-operative bone growth resulted in severe jaw deformity. Therefore, secondary reconstruction was performed, involving vertical osteotomy at the region between the canine and first premolar on the left side and the distal region of the right canine, and a left sagittal splitting procedure (parallel method) of the ramus. Fresh autogenous iliac bone was then grafted to complete correction.
The neck is said to be the most common site in the incidence of lipoma. Lipoma of the neck is treated in various hospital departments. However, few comprehensive investigations into this pathology have been reported. We report here a case of huge lipoma of the neck with a review of the literature.
Benign tumors or tumor-like lesions occurring in the base of the maxilla and in the maxillary sinus are routinely extirpated through the canine fossa. However, complete extirpation may be difficult with the possible risk of recurrence when the lesion is relatively large, as this technique may not permit adequate visualization of the procedure. Hemimaxillectomy to produce complete extirpation may, on the other hand, produce considerable morphologic as well as functional disturbances. We recently experienced a case of relatively extended osteoma originating in the maxilla. Extirpation was performed by means of the modified Le Fort I osteotomy, usually utilized in the field of orthognathic surgery, with favorable results. This approach will in the future be considered the operative procedure permitting of choice, extensive lesions removal of even under direct vision and symmetric countenance post-operatively by performing bone grafting into the bone defect site.
An analysis was made of the clinicopathological features of 32 odontogenic keratocysts from 24 patients in the files of the 2nd Department of Oral surgery, Tohoku University, School of Dentistry. And the relationships between developmental odontogenic cysts and odontogenic keratocysts were discussed. Case selection of odontogenic keratocysts was made on the basis of Pindborg and associates histologic criteria. Odontogenic keratocysts were found in 16 males and 8 females. Patient age rangedfrom 13 to 62 years old. Peak incidence was in the second decade of life. The mandible: maxilla ratio was 2.2:1, with the mandibular third molar and ramus area being the most common site. The radiographic appearance of 27 regions of 32 odontogenic keratocysts inthis study could be described as having unilocular smooth periphery in 13 regions, a unilocular scalloped periphery in 8 regions, and a multilocular periphery in 6 regions. Clinically, 12 odontogenic keratocysts were found in association with an impacted tooth, and 3 of these were of the dentigerous type. Histologically, total parakeratinization was the most common finding and occurred in the epithelial lining of 29 cysts. In 3 cysts, the epithelial lining contained areasof parakeratinization and orthokeratinization. Budinglike proliferation of basal cells was found in the epithelial lining of 17 cysts. Seventeen cysts contained islands or foci of odontogenic epithelium. Daughter cysts were present in 7 cysts. In 19 cases permitting 1 year follow-up, 6 cases of recurrence were noted with arate of 32%. In this study, the rate of recurrence of cysts totally extirpated in one piece was only 8%, whereas the rate of recurrence of cysts removed in several pieces was 71%. We therefore considered that the most significant factor in the recurrence of odontogenic keratocyst was the incomplete extirpation of the cystic wall.
Secondary closure of alveolar clefts without bone graft were performed in six patients with narrow alveolar clefts. The patients' ages ranged from 10 to 12 years 4 months. The surgical technique was similar to bone grafting methods. The alveolar clefts were completely exposed and the bone surfaces were carefully roughened by chiselling. The maxillary defect was then closed by suturing the nasal, palatal and labial mucoperiosteal flaps. As a result, a bone the bridge was formed in the alveolar clefts of all cases. Bone bridging time was from 3 months to 1 year 2 months after operation.
Clinical application of the polyvinylalcohol (PVA) sponge in the extirpation of maxillary bone cyst is presented. PVA sponge material is now widely employed industrial products, household utensils, and medical instruments. PVA sponge is highly hydrophilic and water-absorbant due to its continuous microporous structure. Because of this, we considered that PVA sponge might possess both tamponade and drainage functions. Thus, we used PVA sponge in the extirpation of maxillay bone cyst when radical surgery of the maxillary sinuses was simultaneously performed. PVA sponge was introduced into the antral cavity and brought out through the nose. PVA sponge was usually removed on the second day after operation. The result was satisfactory: little pain and bleeding was noted when the PVA sponge was removed. In addition, postoperative buccal swelling was considerably reduced.
Clinicostatistical observation was made into 34 cases of mandibular condylar fracture in children under 15 years by reviewing recent results of treatment given at our hospital during the past 16 years, from April 1971 to March 1987. Results obtained were as follows: 1. Fractures to the condyle were diagnosed in 58.6% of 58 cases of childhood mandibular fractures. 2. Of 34 cases, 26 cases showed fractures to the condayle combined with other fractures of the mandible. 3. Closed reduction was performed in 26 cases. 4. Open reduction was performed in 8 cases and condylar process was performed in only 1 case which showed combined subcondylar and other mandibular fractures. 5. Long-term follow-up study gave the following results: 1) Disturbances were found to bear some relation to age. 2) Open reduction for condylar process fracture was performed in 1 case, showing good prognosis. 3) There was no obvious difference in the clinical course between closed and open reduction. 4) Temporo-mandibular movement and range of movement were satisfactorily restored, but in most cases deformity of the condylar process remained. 5) 3 cases with growth disturbance of the mandible were observed.
Cells with a transparent cytoplasm are often seen in organs such as the kidney and adrenal glands, and often appear in salivary gland tumor cells such as mucoepidermoid or acinic cell tumors. However, clear cell adenoma of salivary glands is very rare. A 53-year-old male demonstrated a mass in the left oral floor and was treated by surgical resection. It was not strongly adherent to the surrounding tissue. Histo-pathologically the tumor tissue was found to be exclusively composed of clear cells arranged focally and linearly. The clear cells in this case were of a nonmucoid type which may or may not contain glycogen. I mmunohistochemical staining was negative for CEA, S-100 protein and SCC antibody. The average number of Ag-NORs were 1.47 suggesting a low grade of malignancy. Morphologically speaking, clear cell adenoma can be divided into two variants: bimorphic and monomorphic. The case in study was of the monomorphic type. Follow up was performed for 2 and half years no evidence of metastasis or local recurrence was noted during that time.
A 54 year-old male patient with lateral lingual lymph node metastasis from tongue cancer is reported. A well-differentiated T 2 N 0 squamous cell carcinoma of the right tongue border was treated primarily with interstitial radium irradiation. However, local recurrence was noted 4 months later. At the same time, a slight articular disorder developed. Hemiglossectomy in conjunction with bilateral neck dissection was carried outby pullthrough operation. A solitary lesion 0.8cm in diameter was encountered abovethe greater cornu of the hyoid bone, invading into the digastric and hyoglossal muscles and the hypoglossal nerve. Hemiglossectomy was accompanied by the inclusion of the right half of the hyoid, upper part of the strap muscles and extracranial hypoglossal nerve in the surgical specimen. From its anatomical location and histologic findings, the lesion exhibited metastasis in the lateral lingual node that showed extracapsular spread. No other cervical nodes were involved. No evidence of disease was noted during the 6 month follow-up period.
The diagnostic significance of findings in salivary gland biopsies was evaluated in 4 groups. Group I (32 cases): control (normal female) Group II (22 cases): sialaporia (10-20ml/10 min by gum-test) Group III (21 cases): “probable” Sjögren's syndrome. Group IV (55 cases): “definite” Sjögren's syndrome. The diagnosis of Sjögren's syndrome was based on criteria established by the Ministry of Health and Welfares Sjögren's syndrome Committee. The results were as follows: 1. Changes in duct epithelium (destruction and/or proliferation of the duct epithelial cells, formation of epimyoepithelial island-like structures) were observed tobe more prominent in group ET than in other groups. 2. Changes in intralobular duct epithelium were more severe in group IV than in other groups. 3. The incidence of periductal foci (an aggregate of 100 or more lymphoid cells and histiocytes) in d labial salivary glands was 72.7% in group IV, higher than the other groups. Diffuse lymphoid cell infiltrations were observed to be prominent in group IV. 4. The incidence of cases demonstrating one or more periductal foci (an aggregate of 50 or more lymphoid cells) per lobule was noted to be highest in group IV. 5. The periductal foci recognized in groups III and IV were composed mainly of lymphocytes. 6. Changes in glands (interstitial fibrosis, atrophy, destruction and disappearance of acinal parenchyma) were more severe in group IV than in other groups. 7. Although salivary gland biopsies are an important addition to available diagnostic procedures for Sjögren's syndrome, this method may not be entirely adequate to confirm the diagnosis of this disease.
The present paper reports two cases of calcifying odontogenic eyst, including a review of previously reported cases of the lesion in Japan. Case 1: A 24-year-old woman had a painless swelling in the right maxillary incisor region. The radiographic examination showed an ovoid radiolucent area containing several small radiopaque spots. The lesion was enucleated. Histopathological findings from the specimens showed the presence of ghost cells and calcified tissues in the connective tissue around the cyst wall. The patient had an uneventful postoperative course and the follow-up radiographs were not available for study. Case 2: A 32-year-old man was referred complaining a mental mandibular swelling which had been present for one year. The radiographic examination showed two cystic radiolucent area from the right incisor to the left second premolar area, and tooth-like appearance could be found in the left one. These cysts were enucleated and HAP was consolidated into the bone defect occurred postoperatively. Histopathological findings revealed that the epithelium of the right side cyst contained ghost cells, calcified tissues, and foreign body giant cells. The left one was complex odontoma. Postoperative courses were uneventful and no relapse was found.
Clinical investigation and details of four cases of skeletal class I patients who received simultaneous repositioning of the maxilla and mandible are reported in this paper. Indications for simultaneous two-jaw surgery for select class III dentofacial deformities are also discussed. The restoration of normal jaw function, optimal facial esthetics and long term stability is the sine qua non of successful corrective surgery to class I dentofacial deformities. The keys to this are accurate three dimensional analysis, planning and surgery based on foundations of clinical, biological and biomechanical examination. The following four groups of select class I dentofarial deformities qualify for simultaneous two-jaw surgery: (1) severe class I dentofacial deformities without vertical and transverse deformities, (2) class jil dentofacial deformities with vertical maxillary excess, (3) class III dentofacial deformities with vertical maxillary deficiency and (4) class I dentofacial deformities with maxillary asymmetry. However, group (1) was small. The majority of class III dentofacial deformities requiring simultaneous two-jaw surgery were types (2), (3) and (4).
Fracture of mandible is frequently seen in the oral and maxillofacial surgical field. We treated 38 of 363 mandibular fracture cases by open reduction, and divided these cases into two groups, with and without condylar fracture. Patients with condylar injuries were treated by several methods including arthroplasty, condylectomy, excision of the fractured segment and K-wire pinning. Patients with no condylar fracture were treated by A-0 plating and/or miniplating. Postoperative complications included two infections in pathologic fracture cases and one infection in a condylar pinning case; other complications were two cases of minor occlusal discrepancy and one case of slight nerve injury related to condylar fracture.