In this study, we ultra structurally evaluated the interface between granular diopside and diopside-induced hydroxyapatite (HAp), and presented a growth mechanism of HAp at the surface of diopside.Specimens were prepared in the following two experiments.
1) Granular diopside immersed in the simulated body fluid for 5 days.
2) Granular diopside implanted into the rabbit bone cavity and left for 1 month.
In the first step, epitaxial crystal growth of octacalcium phosphate (OCP) occurs in the diopside surface layer.The epitaxial relationship of OCP on diopside are as follows,
(001) _di// (010) _ocp
[110] _di, // [100] _ocp
The lattice mismatch between the c-axis of OCP and [110] of diopside is 3.7% whereas between the a-axis of OCP and three times of [110] period of diopside is 0.05%.
In second step, OCP changed to HAp by topotactic phase transition. The topotactic relationship between OCP and HAp are as follows,
a_ocp=2a HAp
b_ocp=b_HAp
c_ocp=c_HAp
In the early period, HAp crystals observed were platelet-shaped.It is influecned considerably by the shape of OCP. HAp grows into a hexagonal prism shape.

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5例の嚢胞摘出後の顎骨欠損部に対し, 旭光学社製の非吸収性生体活性ハイドロキシアパタイト・セラミックス顆粒(アパセラムG^®)を応用し, その使用方法と臨床経過について検討を加えた。

その結果, 本顆粒の使用により, 術後の歯槽骨の形態が保持できた。また, 嚢胞腔内の膿汁貯溜例には, アパセラムを抗生剤溶液に浸漬した後に使用したところ, 術後の感染例はなかった。術後12~15ヵ月の経過観察期間ではあるが, 患者は補綴物を装用でき, また, 術創の異常経過もみられていない。

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A model of severely atrophic mandible is modified with wax to a desired postoperative ridge form. An extended surgical splint is produced from clear acrylic resin.
After completion of the subperiosteal tunnel dissection, the surgical splint is fixed to the mandible with circummandibular ligatures. Hydroxyapatite particles are injected into the tunnel.
This method can prevent migration of hydroxyapatite particles and reduce extension of the alveolar ridge.

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Properties of diopside, CaMgSi₂O₆, powder prepared from metal alkoxides were investigated examine for its application as a biomaterial. Gel powder was synthesized by hydrolysis of mixed alkoxides, i.e. Ca(OEt)₂, Mg(OC₂H₄OEt)₂ and Si(OEt)₄. The hydrolyzed product was characterized by SEM, DTA, XRD, ICP and so on. The dry gel powder was X-ray amorphous and crystallized into diopside at 840°C. This amorphous powder showed better sinterability than that of the crystallized powder. The calcined powder could be coated on Ti metal by a thermal treatment at 800°C for 2h. The diopside coated Ti metal composite was expected to be useful for biomaterials as artificial bone and dental root.

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The hydration and hardening characteristic of materials in the system CaO-MgO-SiO₂ have been investigated by XRD, SEM, FT-IR and calorimetry. 2CaO⋅MgO⋅2SiO₂ glass hydrated and calcium silicate hydrate gels (C-S-H) were formed after 90min of curing. Diopside did not hydrate. The compressive strength of the hardened cement (at 37°C for 6h) was 27MPa. The setting time for the crystalline sample in ammonium phosphate solution was 4-6min and that for the glass sample was less than 3min. It is expected that CaO-MgO-SiO₂ cement is useful as a biomaterial.

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This article presents four cases of erectile hemangioma in the masseter muscle. These four patients, age 48 female, 18 male, 17male, 21 female, had same symptoms; enlargement of masseter portion follows muscle contraction. In all of cases, the swelling lesion took many years to become large. On the clinical examination, the swellings were immediately followed by masseter muscle contraction. The size and the hardness of the swelling gradually reduced during the patient kept contract on. In case 1 and case 2, the operations were performed after injecting silicon impression materials (for dental use) into the main cavities of hemangioma. This method makes it easier to resect the tumor. Case 3 was treated by extraoral approach and case 4 resected by intraoral approach. The pathological diagnosis of the first two cases were cavernous hemangioma and the last two cases were venous hemangioma. No patient had complications and recurrence.

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Sebastian platelet症候群は, 1990年にGreinacherらにより報告された, 巨大血小板を伴う血小板減少症と白血球封入体の存在と出血傾向を特徴とする遺伝性の疾患である. 今回われわれは, 本疾患の下顎智歯抜去を経験した. 症例は19歳, 男性で歯科矯正医より智歯抜去依頼にて紹介され当科を受診した. 問診および術前検査において血液疾患を疑い, 諸検査の結果, 血液内科にてSebastian platelet症候群と診断された. 抜歯後の止血管理について検討した結果, 血小板減少患者の抜歯基準に沿って行うこととした. 局所麻酔下で抜歯術を施行し, 局所止血にはアテロコラーゲンの填塞と縫合を行った. 術中および術後に著しい出血などの異常は認めなかった.

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Glass-ceramics were searched for in the systems based on CaO-MgO-SiO₂-TiO₂-Ag₂O. The glasses melted at 1500°C could be cast. The absorptions were measured. Silver colloids formed in the glasses of composition CaO⋅MgO⋅2SiO₂⋅0.375TiO₂⋅0.007Ag₂O, and CaO⋅MgO⋅2SiO₂⋅0.49TiO₂⋅0.007Ag₂O. The crystallization of diopside of these glasses are controlled by volume nucleation and growth processes. It is shown that the activation energy for crystallization of diopside decreases of these glasses. A fluidity of diopside glass was observed at 800-900°C by the viscous flow mechanism. It can be formed precisely and crystallized under pressure of 0.15MPa at 850°C for 40min, and the glass-ceramics contained crystalline diopside. The bending strength was about 350MPa. This glass-ceramics crystal phase look similar to natural teeth in color and translucency without any deformation. Such a press-forming method is superior to casting method because it is free from pores, and it can be formed lower temperature than 900°C regardless of the glass has high melting point.

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May-Hegglin anomaly is a rare autosomal dominant inherited disorder characterized by giant platelets, thrombocytopenia, and inclusion bodies in granulocytes. Clinically, because of thrombocytopenia, a mild hemorrhagic diathesis may occur. We extracted the mandibular third molar in a patient with May-Hegglin anomaly whose platelet count was visually reduced to 1.6 × 10⁴/μL. The patient was a 27-year-old woman, and the right mandibular third molar to be removed had completely erupted. In this case, good results were obtained with no postoperative bleeding only with local hemostasis (use of an absorptive hemostatic agent, gingival suture). In conclusion, in patients with May-Hegglin anomaly, even if the platelet count on visual observation is as low as 1.6 × 10⁴/μL, tooth extraction is considered possible when an appropriate local hemostatic method is applied.

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This case report describes an erectile hemangioma of the masseter muscle. The patient was a 21-year-old male with a 10-year history of illness who experienced bulging of his right cheek when he chewed. Because a hemangioma of the masseter muscle was suspected on the basis of a MRI study, resection was performed from within the oral cavity. The histopathological diagnosis was a cavernous hemangioma containing 3 phlebolith within the tumor mass. At the present, 3 years postoperatively, there are no signs of recurrence.

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Hydroxylapatite is a particulate bone substitute material that has been studied extensively for use in oral and maxillo-facial surgery. This material, however, is limited in its application due to its particulate nature. At the time of placement it lacks form and cohesive strength, and particles may be misplaced or may compress, dislodge, or migrate under externally applied forces. In light of these problems, it seemed appropriate to develop a method for containing the particles during a period of the time following implantation, until natural healing occurs. A preliminary report of the use of Polyglactin 910 tube (Vicryl^[○!R]-Schlauch : V-S) to contain particulate hydroxylapatite (HAP) used for implantation of bone defects in rabbits is presented. V-S, approximately 10mm in diameter, were fabricated, placed, and filled with HAP on surgically created bone defects against the buccul cortex of the mandible in rabbits. Specimens were obtained at 1, 3, 6, 8, 12 and 18 weeks, the results showed that when the HAP was contained within V-S, displacement of particles was prevented and better HAP forming was possible. Absorption of V-S took place between 6 and 12 weeks, after which the histologic features were the same as those seen when HAP was implanted alone. Using V-S as container material achieved guided tissue regeneration effects. A new, efficacious delivery system is proposedfor the augmentation of atrophic alveolar ridge as well as implantation of bone defects using HAP contained within V-S.

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The May-Hegglin anomaly is an extremely rare, autosomal dominant inherited disorder characterized by the triad of thrombocytopenia, giant platelets, and Döhle-like inclusion bodies in granulocytes. As a result of thrombocytopenia, a mild hemorrhagic diathesis may occur clinically, and special consideration is needed for surgical treatment. However, high-dose γ-globulin therapy, cortical steroids, and immunosuppressants are reported to be ineffective. We performed bilateral extraction of impacted wisdom teeth in a patient with May-Hegglin anomaly. Preoperative hematological examination revealed that the platelet count was 5.5×10⁴/μl. We applied cotton type atelocollagen to the extraction cavity, and complete primary hemostasis was obtained. The patient was not given platelet transfusion. No postoperative hemorrhage occurred, and the patient's progress was good.

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Hemangiomas involving the skeletal muscles are relatively uncommon and often difficult to diagnose. A 16-year-old male patient was referred to our department for treatment of erectile hemangioma in the masseter muscle. The erectile hemangioma was characterized by the swelling in the malar region during contraction of masseter muscle. Surgical removal of the tumor was performed by an extraoral approach. The postoperative course was uneventful and facial palsy did not occur. A case of erectile hemangioma in the masseter muscle is presented along with a review of the literature.

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Six cases of myxoma of the jaw were studied clinicopathologically. The subjects included four males and two females aged 16-59 years (mean 34.5 years). Tumors developed in the mandibule in all cases and were located between unilateral anteriors and molars in three cases, in the unilateral molar region in one case and between bilateral molars in two cases. Expansion of the mandibular bone was noted in each case. Radiographically, multilobular and unicystic appearances were observed in two and four cases respectively. No case revealed impacted teeth. Two cases each were treated by partial mandibular resection, regional resection, and enucleation with curettage. Follow-up was performed from nine months to two years and nine months for each case, and there has been no evidence of recurrence. Histologically, tumors revealed sharp spindle cells arranged in regular or random directions in the background of loose, mucoid-rich stroma. A case showed cystic structures, including mucoid materials, and another was rich in odontogenic epithelia.

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The bone formation in the soft tissue with combined grafts of three categories of HAP granules and autogeneous bone marrow were examined histologically.
Two kinds of HAP granules were on the market (Apaceram^® and Bonetite^®) and another was newly developed (Kobeceram). Autogeneous bone marrow was obtained from New Zealand white rabbit tibia. Combined materials of each HAP granule and bone marrow were grafted into the abdominal subcutaneous regions of rabbits, and bone formation at four weeks after graft were observed histologically.
The results were as follows: In all groups, new bone formations, which were induced with osteoprogenitor factor in bone marrow, were observed, and histological examination of the 4-week specimens revealed excellent HAP-bone complex formations in the Apaceram^® and Kobeceram groups. Process of HAP-bone complex formation with combined graft of HAP granules and autogeneous bone marrow was similar to that which was observed when HAP granules were grafted into the rabbit tibia.

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There exists many clinical and pathological classifications of the division of hemangioma. Recently, an opportunity arose to treat an unusual case of cavernous hemangioma in the masseter muscle (WHO classification). To date, only 11 such cases have been reported in Japan. Strong mastication by the patient resulted in a clear swelling of the tumor region, but without mastication no swelling was observed. These clinical characteristics identified this case as erectile hemangioma of the masseter muscle. The patient, a 15 year-old male, was admitted to our hospital in September, 1988 complaining of abnormal feeling and swelling of the left buccal region.
With strong mastication, a limited hemisphere, painless, elastic soft swelling measuring 48×28mm was seen. It was necessary to identify the origin of this tumor and to find a successful operation method.
There are three possible excision methods for cases of erectile hemangioma, dependent on the location of the incision which can made both extra-orally and intra-orally. The extra-oral incision can be made at the anterior auricular or at the submandible.
The intra-oral method is popular for avoiding the effects of scar tissue. However, this method affords no clear view of the incision line, and can result in excessive bleeding, facial palsy and possible recurrence of the tumor. For the above mentioned reasons, and with the tumor region which was positioned centrally and near the surface of the face, it was decided to make the incision extra-orally at the submandible. The operation appears to have been successful with a good prognosis.

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In a 10-year-old girl, computed tomography showed a lobulated encapsulated mass in the masseter muscle. The mandible was greatly deformed by the tumor. Although benign tumor of the masseter muscle was suspected, we could not rule out malignancy. Histological examination of frozen sections revealed hemangioma. The tumor was removed totally without complications. In this patient, the extraoral approach, which provides wide exposure and facilitates total removal of the tumor, seemed more suitable than the intraoral approach. The characteristics, clinical features and treatment of intramuscular hemangioma are discussed.

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A new method of ridge extension using hydroxyapatite particles is described. This method was applied to a patient who received transplanted iliac bone after the resection of gingival carcinoma. Ridge extension using autogenous bone has the disadvantage of possible resorption neccessitating further surgery. Hydroxyapatite however, is not absorbed and was therefore selected as being suitable for ridge extension. There are various types of hydroxyapatite ie porous particular, dense particular, porous block and dense block types.
Block type is most suitable for alveolar process formation, but perforation is a frequent problem. Porous particular type resists infection due to of discharging particle individually. Alveolar process formation is difficult, and suitable methods for the application of hydroxyapatite particles to the resected and reconstructed jaws have yet to be found.
We report a new method of ridge extension using hydroxyapatite particles, obtaining satisfactory results even in a unfavorable cases.

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