Yukio Fujioka

Evaluation of mandibular reconstruction techniques following resection of malignant tumors in the oral region

Over the past 15 years, reconstruction following excision of malignant oral tumors was performed on 27 patients with segmental resection and five patients with hemiresection of the mandible. Following segmental resection, the mandible was reconstructed using an autogenous bone graft in eight patients in whom the surrounding soft tissues were fairly well preserved. Bony union was achieved in six of them. In the remaining two, the graft was removed because of postoperative infection, and one patient underwent secondary bone grafting. A pedicled myocutaneous flap and bone graft was used in seven patients who underwent extensive resection of the surrounding soft tissue. Bony union was achieved in three patients, and one developed pseudoarthrosis. The graft was removed in the remaining three because of postoperative infection. Reconstruction with only a metallic plate for stabilization of the mandible was carried out in six aged or sarcoma-affected patients. In two of them, the postoperative course was uneventful for 4 to 7 years. In the remaining four patients, plate removal was required because of exposure or tumor recurrence. In 5 of 11 patients in whom reconstruction was carried out with a combination of a pedicled myocutaneous flap and metallic plate, the postoperative course was uneventful for 2 to 8 years. Two of these five patients underwent secondary bone grafting. In four of the remaining six patients, the plate was removed because of exposure or improper adaptation to the stump. Two others died of disseminated intravascular coagulation syndrome within 1 month. A prosthesis was used more frequently by patients when reconstruction was performed using a pedicled osteomyocutaneous flap. The metallic reconstruction plate was helpful for restoring mandibular contour.(ABSTRACT TRUNCATED AT 250 WORDS)

Multiple cemento-ossifying fibroma

This report concerns a case of multiple cemento-ossifying fibroma involving the maxilla and mandible of a 55-year-old Japanese male. The clinical, radiographic and histopathological findings are presented and discussed.

Auto-immune mechanisms as a probable aetiology of Behet's syndrome, an electron microscopic study of the oral mucosa

A constant and characteristic feature of Behcets syndrome was the association of macrophages with degenerated prickle cells in the prickle-cell layer of the oral mucosa adjacent to ulcerations. Three types of macrophages could be identified: Thetype I macrophage, rich in cytoplasmic organelles, phagocytosed material from degenerated cells. Thetype II macrophages with scant endoplasmic reticulum came in contact with small lymphocytes which they gave immunological information, inducing them to undergo blastoid transformation. These lymphoblasts produced immunoglobulins. Lymphoid cells that contained numerous ribosomes and polysomes were attached to the prickle cells and probably elaborated a cytotoxic factor, since the cytoplasm of the prickle cells ultimately degenerated and the ulcer expanded. The cytoplasm of prickle cells apparently acts as an auto-antigen. Immune responses against it are mediated by the macrophages and the lymphoid cells. The changes seen are consistent with those of delayed hypersensitivity reactions.Type III macrophages had Birbeck granules and were regarded as Langerhans cells. Thymus-dependenttype III macrophages may have an important role in developing and controlling the ulceration in Behcets syndrome. The involvement of lysosomes in initiating the ulceration is discussed.A constant and characteristic feature of Behçets syndrome was the association of macrophages with degenerated prickle cells in the prickle-cell layer of the oral mucosa adjacent to ulcerations. Three types of macrophages could be identified: Thetype I macrophage, rich in cytoplasmic organelles, phagocytosed material from degenerated cells. Thetype II macrophages with scant endoplasmic reticulum came in contact with small lymphocytes which they gave immunological information, inducing them to undergo blastoid transformation. These lymphoblasts produced immunoglobulins. Lymphoid cells that contained numerous ribosomes and polysomes were attached to the prickle cells and probably elaborated a cytotoxic factor, since the cytoplasm of the prickle cells ultimately degenerated and the ulcer expanded. The cytoplasm of prickle cells apparently acts as an auto-antigen. Immune responses against it are mediated by the macrophages and the lymphoid cells. The changes seen are consistent with those of delayed hypersensitivity reactions.Type III macrophages had Birbeck granules and were regarded as Langerhans cells. Thymus-dependenttype III macrophages may have an important role in developing and controlling the ulceration in Behçets syndrome. The involvement of lysosomes in initiating the ulceration is discussed.

Massive osteolysis of the mandible.

This report deals with a massive osteolysis, which is a rare disease characterized by the progressive dissolution of contiguous osseous structure, occurring in the mandible of a 46‐year‐old Japanese female. Histopathologic examination of the amputation material revealed that the mandibular body, ramus, condylar and coronoid processes were completely replaced by fibrous tissue, but inferior alveolar nerve and artery in the lesion were intact. A few small islands of osteoid tissue or immature fibrous bone were seen in the lesion. In the transitional area between the lesion and normal bone, active absorption of bone trabeculae was in progress and intertrabecular spaces were occupied by densely packed fibroblastic cells, however, angiomatous proliferation of vessels was not observed. A few bone trabeculae were surrounded by osteoclasts, but osteoclasts might not play a primary etiological role in massive osteolysis.

Possible role of apoptotic cells of the oral epithelium in the pathogenesis of aphthous ulceration

Electron microscopic examination of the normal oral mucosa of patients with recurrent aphthous ulceration or Behçets syndrome revealed that the degenerate dark prickle cells are apoptotic cells. Such dark prickle cells showed characteristic findings of apoptosis, such as the shrinkage of nucleus and cytoplasm and the formation of contraction vacuoles. The number of intraepithelial mononuclear cells phagocytosing apoptotic cellular debris increased remarkably at the preulcerative stage of the aphthous lesions. The apoptotic debris also attracted neutrophilic leukocytes in the prickle cell layer at the preulcerative stage but not in the normal oral epithelium. It is speculated that the onset of aphthous ulceration is closely related to phagocytosis of these apoptotic cells by intraepithelial mononuclear cells.

MELANOCYTES IN ODONTOGENIC KERATOCYST

Melanocytes in odontogenic keratocyst (OKC) were studied histopath‐ologically. As a result, melanocytes were observed within the basal layer of lining epithelium in five of 47 cases with OKC, with the overall prevalence being 10.6 per cent. Although no conclusion could be drawn from the present examination as to the origin of melanocytes in OKC, its possible histogenesis was discussed. ACTA PATHOL. JPN. 35: 899–903, 1985.

PIGMENTED VARIANT OF CALCIFYING ODONTOGENIC

A case of the pigmented variant of calcifying odontogenic cyst occurring in a 21‐year‐old Japanese male is reported, and a review of previously reported cases of the lesion is included. In addition to the characteristic histopathologic features of calcifying odontogenic cyst, dendritic cells containing melanin pigment were widely distributed in the epithelial layer and melanin pigment was also found in the epithelial cells including ghost cells in the present case. Although no conclusion could be drawn from the present examination as to the origin of melanin pigment in the calcifying odontogenic cyst, it is thought that the role of racial pigmentation is one of the important factors in occurrence of pigmented odontogenic lesions. ACTA PATHOL. JPN. 35 : 1023–1027, 1985.

Clinical application of dental implant with root of coated bioglass: Short-term results

During the last 4 years 73 dental implants with root-coated bioglass to replace one to three teeth in the premolar and molar sites of the mandible were inserted. The bonding ratio between implant and bone was observed clinically 1 year after implantation and installation of the superior structure. This ratio measured 52.4% to 63.3%. An acoustoelectric tester was developed that advanced our skills. The emphasis was placed on a tight fit between implant and surrounding bone.

XANTHOGRANULOMA OF THE ORAL CAVITY IN ADULT A Case Report and Review of the Literature

A case of xanthogranuloma arising in the palatal gingiva of the maxilla in a 38‐year‐old Japanese male was investigated. Histopathological findings of the excised lesion were indistinguishable from the xanthogranulomas in infants and children (juvenile xanthogranuloma), and like those in the young, the present case was not associated with abnormalities of serum lipids and was not associated with other lesions. A review of the English literature yielded only two histopathologically documented cases of xanthogranuloma in the oral cavity, arising in young patients. A case of xanthogranuloma of oral cavity in an adult was not documented previously. ACTA PATHOL. JPN. 36: 1565‐1570, 1986.

Clinical course and evaluation of shape and function after reconstruction using various pedicle flaps for oral and maxillofacial defects

In the past 7 years, reconstruction using various pedicle flaps for oral and maxillofacial defects, was carried out for 40 patients. Pectoralis major myocutaneous, deltopectoral and scalp-forehead flaps for large defects, and sternocleidomastoid, cervical island skin and palatal flaps for moderate defects were indicated. As for results, most of the flaps used at the reconstructed site for the defects of soft tissue repaired the shape and patients were satisfied. However, the recovery of functions concerning speech, swallowing or mastication was not always successful with the larger defects, especially after the reconstruction for defects of tongue, floor of the mouth, cheek and mandible for which mandibular reconstruction was performed. It was pointed out that the main causes for less tongue mobility were due to scar contracture after reconstruction, and difficulty of mandibular reconstruction due to postoperative infection were associated factors. Accumulated survival rate of patients for 5 years was 62.6%, in which 38 advanced malignant tumors were reconstructed following surgery. In the clinical course after reconstruction, patients with primary tumors experienced much better results than those with secondary tumors.