Chapter 13 : Clinico-Pathological Healing of Periapical Tissues in Aged Patients by Root Canal Filling using Calcium Hydroxide: Case resentation

Two root canal filling materials, Calvital and Vitapex (Neo Dental Chemical Products Co., Ltd., Tokyo, Japan), were used to treat six teeth in a 78-year-old man and one tooth in an 82-year-old woman, respectively. Both of these filling materials were paste, consisting chiefly of calcium hydroxide and iodoform. One year later these teeth, along with surrounding alveolar bone, were examined histopathologically following the patients’ deaths. Of the six teeth treated with Calvital, four were instrumented prior to root canal obturation and two were not. The teeth that were instrumented prior to obturation showed good healing, while those that were not showed poor healing. The tooth treated with Vitapex was instrumented prior to obturation and showed good periapical healing and osteoid closure of the apical foramen. This finding suggests that canal instrumentation followed by obturation with Vitapex can allow favorable healing even in aged patients.Editor, Toshiyuki KawakamiLanguage Editor, David M Carlsonviii, 232 p. ill. (some col.

Chapter 2 : Tissue Reaction to Root Canal Filling Material Embedded Subcutaneously in Rats

The reaction of subcutaneous connective tissues to root canal filling material pastes, made chiefly of calcium hydroxide, has been studied by means of radiography, histopathology, and electron microscopy. Radiography has revealed that embedded paste displays a well-demarcated radiopaque mass just after embedding, then gradually disappears over time. The resulting images have shown granulation tissue appearing, as well as and the phagocytosis by macrophages and giant cells, as observed histopathologically. Furthermore, there have been heterotopic calcifications within the proliferating granulation tissues in some cases, with electron microscopic examinations revealining phagocytosis. In the present study, the ultrastructural aspects of initial calcification in rat subcutaneous tissues elicited by root canal filling material paste, made up of calcium hydroxide and iodoform with the addition of silicone oil, were examined. The embedded paste caused heterotpic calcifications, which can be divided into two types: dystrophic calcification; and matrix vesicle calcification, which resembles that of bone tissue. These data suggest that the paste may elicit the differentiation of osteoblasts and/or cementoblasts from mesenchymal cells in periodontal ligament.Editor, Toshiyuki KawakamiLanguage Editor, David M Carlsonviii, 232 p. ill. (some col.

Chapter 5 : Deciduous Tooth Resorption after Overfilling of Root Canal Filler: Function and Nature of Multinucleated Giant Cells

There are numerous reports on physiological root resorption claiming that the root resorption process of primary teeth is regulated in a manner similar to bone remodeling [28]. However, complex histological changes occur under several pathological conditions. Abnormal tooth resorption could be found in primary teeth due to certain causes until the completion of the permanent dentition. In Japan and eastern Asia, calcium hydroxide paste with silicon oil added iodoform is widely used for endodontic treatment of deciduous teeth. This material is sometimes excessively filled within root canals, and pathological reactions have been already discussed in previous sections. In this part, the influences on deciduous tooth endodontic therapy will be described in detail. The most characteristic feature is abnormal tooth resorption via osteoclast-like multinucleated giant cells (MGCs) and foreign body giant cells (FBGCs). In the later part of this section, the characteristics of foreign body type giant cells will be discussed through in vivo experiments.Editor, Toshiyuki KawakamiLanguage Editor, David M Carlsonviii, 232 p. ill. (some col.

bFGFの皮下注射は授乳期における新生児マウスの下顎頭の発育を促進する

To elucidate the effect of local bFGF administration, we administered a total of 0.3μg rhbFGF was to the left mandibular condyle by three injections of 0.1μl bFGF solution for 3 days after birth. The contralateral condyles with three injections of 0.1μl physiologic saline served as controls. Serial sections including the widest condyle were evaluated with H-E staining and immunostaining for PCNA. The maximum width of condyle, proliferative zone thickness, proliferative zone thickness ratio and proliferating index were analyzed using image analysis software after digital image capture of H-E stained sections. All condyles were composed of fibrous, proliferative, maturation and hypertrophic cell zones without significant abnormal findings. Experimental condyles demonstrated a markedly thickened proliferative zone compared with that of the controls at 1 day after the injection. At 4 and 7 days, chondrocytes and hypertrophic chondrocytes of the experiments increased in thickness. However, at 14 days after the injection, both the controls and experiments showed similar features with an upward shift of ossification front and active formation of bone trabeculae. Morphometrically, all values of experiments were significantly higher than those of the controls. Especially at 4 days after the final injection, proliferative zone thickness and proliferative index values of the experiment reached a peak and were nearly 1.6-fold higher than those of the control, which were statistically significant compared to other experimental groups. Despite the short half-life of rhbFGF, its effect seems to be prolonged by synergic actions of growth factors such as bFGF or TGF beta1. In conclusion, we showed that local administration of bFGF was feasible for accelerating mesenchymal cell proliferation of mandibular condyles of newborn mice in the lactation period after birth.2013博士（歯学）松本歯科大

含歯性嚢胞より生じた原発性骨内歯原性癌腫

Malignant tumors arising from dentigerous cysts are classified as primary squamous cell carcinoma derived from an odontogenic cyst or as odontogenic carcinoma according to the 2005 WHO classification and are extremely rare. We report a malignant tumor arising from a dentigerous cyst in the right maxillary anterior teeth , together with a literature review. The patient was a 75-year-old man who visited a hospital with complaining of discomfort in the lingual part of the right maxillary anterior teeth. On panoramic radiography and plain computed tomography (CT), dentigerous cyst, keratocystic odontogenic tumor or ameloblastoma was suspected. The extirpated material was histopathologically diagnosed as an odontogenic carcinoma (in situ) arising from the dentigerous cyst. Postoperative ultrasonography (US) and contrast enhanced CT revealed no metastasis to the cervical lymph nodes. The patient is currently being followed up without resection or anticancer drug administration. Neither local recurrence nor metastases were observed 18 month after surgery.症例は75歳男性で、右上顎前歯の舌部不快感を主訴として受診した。パノラマX線撮影とCT検査により含歯性嚢胞、角化細胞歯原性腫瘍またはエナメル上皮腫が疑われた。切除切片の病理組織学的検査の結果、含歯性嚢胞より生じた歯原性癌腫と診断した。術後超音波検査と造影増強CT画像では頸部リンパ節への転移は見られなかった。抗癌剤投与はせずに経過観察中で、術後18ヵ月時点で再発や転移は見られていない。含歯性嚢胞より生じる悪性腫瘍は2005年のWHO分類によれば歯原性嚢胞由来の原発性扁平上皮癌または歯原性癌腫に分類され、極めて稀である。本症例は右上顎前歯の含歯性嚢胞より生じた悪性腫瘍であった。他の症例についても文献レビューした

Ectopic transglutaminase 1 and 3 expression accelerating keratinization in oral lichen planus

Abstract Objective: Oral lichen planus (OLP) characterized by interface mucositis frequently shows hyper-keratinization. To clarify mechanisms of excess keratinization, we investigated key molecules for cornified cell envelope (CE). Methods: Involucrin (IVL), loricrin (LOR), transglutaminase 1 (TGase 1) and transglutaminase 3 (TGase 3) were immunohistochemically examined in 20 specimens of OLP; five specimens of buccal mucosa served as controls. Subsequently, the data were statistically analyzed. Results: IVL in OLP was localized in the cell membrane, in contrast to its localization in the cytoplasm in controls. No positive reaction indicative of LOR was noted in any specimens. Although the TGase 1 localization in controls was restricted to the upper three-quarters of the membrane, the localization in OLP was in both membrane and in the cytoplasm of full thickness mucosal layers. The TGase 3 localization pattern was dramatically altered from cytoplasmic to membranous in OLP. Conclusion: Our data suggest that aberrant TGase 1 and TGase 3 localization and distribution are closely related to hyper-keratinization in OLP. This is the first report of ectopic transglutaminase localization in OLP

多形腺腫における細胞分化因子としてのNotchの可能性

The expression of Notch in 30 cases of pleomorphic adenoma was examined by immunohistochemistry.Comparing the results of our study with previous literatures, from the partial CK7 expression and substantial Notch expression in ductal epithelial cells as well as the Notch expression in solid tumor nests, it can be inferred that Notch is involved in cell differentiation. CK13 expression was observed in cells undergoing squamous metaplasia and Notch expression was seen in the nucleus of basal and squamous cells. The intense Notch expression in basal cells and weak expression in squamous cells suggests that Notch is involved in the differentiation from basal to squamous cell. Moreover, the loss of nuclear expression on the inner layer would signify that differentiation is about to end or has been terminated. Notch was expressed in the cytoplasm of cartilage cells and in the cell membrane of mucous cells but not in the nucleus indicating that differentiation has been concluded. Notch involvement is suspected in cell differentiation in areas showing ductal structures and squamous metaplasia. In summary, Notch is involved in cell differentiation of ductal cells in PA. Nuclear expression was shown in tumor cells in solid nests and surrounding structures. Moreover, Notch is expressed by basal cells undergoing squamous metaplasia suggesting the participation of Notch in cell differentiation in PA.2015博士（歯学）松本歯科大

マウスにおける実験的に発生させた歯根膜ポリープへのGFP移植骨髄由来細胞の移動と分化

Perforation of floor of the dental pulp is often encountered during root canal treatment in routine clinical practice of dental caries. If perforation were large, granulation tissue would grow to form periodontal polyp. Granulation tissue consists of proliferating cells however their origin is not clear. It was shown that the cells in granulation tissue are mainly from migration of undifferentiated mesenchymal cells of the bone marrow. Hence, this study utilized GFP bone marrow transplantation mouse model. The floor of the pulp chamber in maxillary first molar was perforated using ½ dental round bur. Morphological assessment was carried out by micro CT and microscopy and GFP cell mechanism was further assessed by immunohistochemistry using double fluorescent staining with GFP-S100A4; GFP-Runx2 and GFP-CD31. Results of micro CT revealed alveolar bone resorption and widening of periodontal ligament. Histopathological examination showed proliferation of fibroblasts with some round cells and blood vessels in the granulation tissue. At 2 weeks, the outermost layer of the granulation tissue was lined by squamous cells with distinct intercellular bridges. At 4 weeks, the granulation tissue became larger than the perforation and the outermost layer was lined by relatively typical stratified squamous epithelium. Double immunofluorescent staining of GFP and Runx2 revealed that both proteins were expressed in spindle-shaped cells. Double immunofluorescent staining of GFP and CD31 revealed that both proteins were expressed in vascular endothelial cells in morphologically distinct vessels. The results suggest that fibroblasts, periodontal ligament fibroblasts and blood vessels in granulation tissue were derived from transplanted-bone marrow cells. Thus, essential growth of granulation tissue in periodontal polyp was caused by the migration of undifferentiated mesenchymal cells derived from bone marrow, which differentiated into fibroblasts and later on differentiated into other cells in response to injury.2016博士（歯学）松本歯科大

A case of intramuscular lipoma of the left buccal region

We report a case of intramuscular lipoma of the left buccal region, along with a review of the relevant literature. Magnetic resonance imaging showed a spindle–shaped mass extending from the canine region to the anterior portion of the masseter muscle in the buccal–alveolar portion of the left mandible. The inner part was visualized as homogeneous high–signal intensity on both T1– and T2–weighted images, and a partial linear region with the same signal intensity as muscle was also observed. The removed tumor measured 35×40×15mm in size, and histopathological findings showed an intramuscular lipoma composed of adipose, muscle and connective tissues. Intramuscular lipomas account for 1.7%–2% of all lipomas, and they very rarely occur in the oral and maxillofacial region. Twenty–three cases with intramuscular lipomas in the oral and maxillofacial region, including our case, have been reported in Japan. The postoperative healing process is generally good. We followed–up our patient after explaining to him the importance of careful, long–term follow–up. It has been only 2 months, to date, since surgery but the outcome appears to be good

A case that has been diagnosed with glandular odontogenic cyst by histopathological examination

Glandular odontogenic cyst (GOC) is a rare odontogenic cyst, classified as a developmental odontogenic cyst by the WHO histological typing of odontogenic tumours in 1992. GOC generally occurs in the mandible and arises in each age. The clinical differential diagnosis of odontogenic tumor and cyst is important however, it is difficult to discriminate between them in clinical and radiographical findings. Thus, pathological searches become an essential step for the definite diagnosis. We report a case of GOC, that primary diagnosis was dentigerous cyst by biopsy, but the definite diagnosis was GOC after total extirpation of cyst. Because of a high recurrence rate of GOC, the patients should be followed for a long term