Hisatoshi Tanaka

Long-term restoration of masticatory function with fixed mandibular implants in cases of oral cancer.

The results of the present study show that the fixed mandibular implant system enables patients who have operations to treat oral cancer to use a stabilized denture continuously over an extended period of time.

Effectiveness of Absorbable Electrified Poly-L-lactic Acid Membrane for Bone Regeneration in Rats.

目的: 本研究は, 生体吸収性で圧電性を有するポリ乳酸膜 (poly-L-lactic acid, 以下, PLLA) を用いた骨誘導再生法が人工的骨欠損部の再生に及ぼす効果を病理組織学的に検索し, Gore-Tex Augmentation material (GTAM®) および圧電性を有しないポリ乳酸膜 (polylactic acid, 以下, PLA) の効果と比較検討することを目的とした.方法: 実験には, 生後13～15週齢のWistar系雄性ラットを使用し, 直径2.0mmの骨窩洞を右大腿骨に形成した. 骨窩洞は, 実験A群ではGTAM®, B群では圧電性を有しないPLA, C群では圧電性を有するPLLA (分子量10万), D群では圧電性を有するPLLA (分子量30万) で被覆して囲続結紮した後, 軟組織で覆い縫合した. 実験期間は2週, 4週とし, 屠殺後, 硬組織研磨標本により病理組織学的観察を行った.結果: C, D群はA群に比較して早期より骨形成と成熟化が促進されていた. 特に, D群で新生骨の形成が窩洞全体に著明にみられ皮質骨全体の厚みを増し, 成熟度も高く, 既存皮質骨と同化していた. A群の骨再生はB群と同程度であり, 各実験期間でC, D群より劣っていた. またPLLAは皮質骨の上に望ましい形態を得るための賦形性に優れていた.結論: PLLAはGTAM®に比較して骨再生促進効果に優れ, 骨誘導再生法により有用であることが示された.

Improved Occlusal Relationship by Prosthodontic Treatment in a Patient of Severe Anterior Open Bite with Rheumatoid Arthritis: Report of Case.

A prosthodontic treatment of a 39-year-old female who had severe anterior open bite with rheumatoid arthritis was reported. Rheumatoid arthritis had been diagnosed 5 years previously, and she had been hospitalized for infection of the spine, shoulder and knee joints. In her medical history, the patient stated that her mandible had continued to gradually retrude for the past 3 years, resulting in severe anterior open bite.Because of the progressive nature of rheumatoid arthritis, the decision was made to perform a reversible procedure to apply a prosthesis made of acrylic resin for stable occlusal contact with a posterior tooth. Afterthe eighth month, even distribution of posterior tooth contact was acquired with decreased vertical overbiteof 1 mm. After maxillary anterior prosthesis made of acrylic resin were provided with suitable verticaloverbite and anterior guidance, the metal prosthesis were provided at fourteen months after the first examination.In this report, it was suggested that occlusal management could improve anterior open bite caused byrheumatoid arthritis of TMJ, however, lateral transcranial radiography of TMJ findings still showed deformityand flattening of the condyle and the articular eminence of bilateral TMJ after treatment.

A prosthodontic approach to the surgical treatment of the epulis fissuratum

Simple excision of the epulis fissuratum results in loss of sulcus dept hand scar formation, hence the peripheral seal of full denture are obstructed. In order to avoid these condition, lyophilized porcine skin or dermis were used to excised surface for wound dressing, and treatment dentures were inserted one week after the operation which act as a splint maintaining sulcus depth. Furthermore, occlusal correction, which included to restore an optimal vertical dimension of occlusion of the old dentures, and correction of the extent of the tissue coverage by the old denture base were accomplished by modifying the old (treatment) dentures.Consequently, it seems that loss of sulcus depth and scar formation were reduced. The ridge relation was improved, and this improvement faciliated the eventual registration of the jaw relation.In broad lesion, it is difficult to correct the extent of tissue coverage by the resin bordermolding materials. Therefore, the extent of tissue coverage of old dentures without lesion by the impression technique before operation, and refitting the excised surface by instant chairside reline technique after the operation, it may be useful for the resolution of this difficulty.