乳歯癒合歯の発現部位と乳歯列に及ぼす影響

The Effects Fused Deciduous Teeth haveon Successional Permanent Teeth and Dentition

松下 愛

海原 康孝

桑原 さつき

池上 明雄

森本 英樹

天野 秀昭

長坂 信夫

小児歯科学雑誌

乳歯癒合歯が後継永久歯の状態,および歯列へ及ぼす影響を検討することを目的とし,乳歯癒合歯を有する80名の口腔内状態および37名のHellmanの歯齢IIA期の研究用模型について,癒合歯の発現部位別に検討した結果,以下の結論を得た。1.乳歯癒合歯は107症例中,上顎18症例,下顎89症例であり,下顎に多く認められた。また,下顎AB癒合が最も多く46症例あり,ついで下顎BC癒合で43症例であった。双生歯は上顎に2症例認められた。2. 両側性に乳歯癒合歯を認めたものは80名中22名(27.5%)であり,そのほとんどは左右対称に癒合歯を有していたが,下顎において左右非対称な部位に癒合歯を有したものを2名認めた。3. 乳歯癒合歯の後継永久歯の状態は,上顎AB癒合15症例中9症例(60.0%) に後継永久歯の欠如を認めた。下顎AB癒合では46症例中9症例(19.6%) に後継永久歯の欠如4症例(8.7%) に後継永久歯の癒合,下顎BC癒合の場合, 43症例中29症例(67.4%)に後継永久歯の欠如, 7症例(16.3%) に後継永久歯の癒合が認められた。4. ターミナルプレーンは癒合側と非癒合側とで大きな差は認められず上顎もしくは下顎AB癒合歯保有歯列では垂直型が多く,片側性下顎BC癒合歯保有歯列では近心型が増加する傾向にあった。乳犬歯佼合関係では片側性下顎AB癒合歯保有歯列では癒合側でE型が増加する傾向が認められた。5. 下顎に癒合歯が存在する場合,下顎歯列弓幅径が狭窄する傾向にあり,特に下顎BC癒合歯保有歯列では顕著であった。下顎の歯列弓長径は両側性に癒合歯が存在する場合,短縮する傾向が強く認められた。

To examine the effects fused deciduous teeth have on successional permanent teeth and teeth alignments,we carried out an investigation of such sites based on a study of the intraoral status of 80 childrenwith fused deciduous teeth, and the use of study casts from 37 people in Hellman Dental ages ofstage II A.1) We observed a total of 107 cases with fused deciduous teeth, and of these, 18 cases were maxillary,and 89 cases were mandibular. The greatest number, 46 cases, was observed for mandibular ABfused teeth, followed by 5 cases of mandibular BC fused teeth.2) Bilateral cases of fused deciduous teeth were observed in 22 out of the 80 cases, with most ofthese cases possessing fused teeth in locations with left-right symmetry,3) Successional permanent teeth deficiencies were observed in 9 out of the 15 cases of fused maxillaryAB teeth. Of the 46 cases of mandibular AB fused teeth, successional permanent teeth deficiencieswere also observed in 9 cases, while fusion of successional permanent teeth Were observed in 4cases. Of the 43 cases of mandibular BC fused teeth, successional permanent teeth deficiencies wereobserved in 29 cases, and fusion of succe~sional permanent teeth was observed in 7 cases.4) Concerning the terminal planes, we were unable to observe any major differences between sideswith fused teeth, and sides without. Tooth alignments where maxillary and mandibular AB were fusedteeth, were of the vertical types, but the mesial types were more numerous in tooth alignments withBC fused teeth on one side of the mandibular. Concerning deciduous canine occlusion relationships,there was a tendency for there to be an increase in type 3 on the fused side of the tooth alignmentswith AB fused teeth on one side of the mandibular.5) There was also a tendency for there to be a narrowing of the lower dental arch width in caseswhere fused teeth were found to exist in the mandibular, and this trend was particularly conspicuousfor tooth alignments where BC were fused teeth. A s

乳歯癒合歯

発現部位

乳歯列

Fused deciduous teeth

Successional Permanent teeth

Dentition

医学 [ 490 ]

日本語

日本小児歯科学会

Copyright (c) 2000 Authors, 日本小児歯科学会

[ISSN] 0583-1199

[NCID] AN00116228