アブストラクト(16巻2号:神奈川歯学)

神奈川歯学

Japanese

Title : 複根を有する下顎永久犬歯の組織像
Subtitle : 原著
Authors : 北村博則, 伊藤哲儀, 坪田不二雄
Authors(kana) :
Organization : 神奈川歯科大学口腔組織学教室
Journal : 神奈川歯学
Volume : 16
Number : 2
Page : 311-320
Year/Month : 1981 / 9
Article : 原著
Publisher : 神奈川歯科大学学会
Abstract : 「まえがき」 下顎乳犬歯の複根例の報告は少ないが, 下顎永久犬歯の複根例は比較的多く, 藤田, 上条, 尾崎, 小林らの報告がある. 藤田は0.5%, 岡本と長田は0.3%, Lenhossekは約9%の頻度で下顎犬歯の複根が発現するというが, 著者らは数万本の抜去歯牙の中から1例を発見したにすぎない. 過去の報告例では, 下顎乳犬歯でも下顎永久犬歯でも唇舌的に分岐した複根をもつものが大多数である. 畑らは下顎の乳犬歯で近遠心的に分岐した珍しい複根例を報告している. 本症例は唇舌的に分岐した複根を有する下顎永久犬歯であるが, この症例の切片を正常の複根歯である上顎第1小臼歯の組織像と比較して, この奇形発現が表現型模写であるのか, 復古型(いわゆる先祖返り)であるのかをきわめる手がかりを見つけようとする次第である.
Practice : 歯科学
Keywords :

English

Title : A Histological Observation of the Two-rooted Permanent Mandibular Canine
Subtitle :
Authors : Hironori KITAMURA, Tetsuyoshi ITOH, Fujio TSUBOTA
Authors(kana) :
Organization : Department of Oral Histology, Kanagawa Dental College
Journal : Kanagawa Shigaku
Volume : 16
Number : 2
Page : 311-320
Year/Month : 1981 / 9
Article : Original article
Publisher : Kanagawa Odontological Society
Abstract : The right mandibular canine with labio-lingually bifurcated roots was examined histologically as a ground section. For the control of this two-rooted canine, three maxillary first premolars with bifurcated roots were examined in the same manner. The following differences were obtained as to the bifurcated area of dentin. 1) An interradicular crista and its related dentin nucleus or nuclei are found in the normal tooth, whereas neither the crista nor dentin nucleus is found in the malformed tooth. 2) The D-C junction demarcated with the granular layer of Tomes is generally relatively clear in the normal tooth, whereas it is obscure in the limited central area of the bifurcated part in the malformed tooth. 3) A very small ectopic piece or pieces of irregular dentin with a number of necrotic cells which resemble intermediate cement are found in the normal case, whereas the ectopic intermediate cement-like tissue with dentinal tubules is very extensively found in the cement area of the malformed tooth. 4) The size of the malformed mandibular canine is smaller as a whole than that of the normal one. Especially the length of both crown and root is relatively short. These findings strongly suggest that the permanent mandibular two-rooted canine is not protostylid but of phenocopy.
Practice : Dentistry
Keywords :