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Delayed development or congenital absence of a single first permanent molar in Japanese child patients
Author(s) -
Nakano K.,
Matsuoka T.,
Takahashi A.,
Matsumura M.,
Sobue S.,
Ooshima T.
Publication year - 1999
Publication title -
international journal of paediatric dentistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.183
H-Index - 62
eISSN - 1365-263X
pISSN - 0960-7439
DOI - 10.1111/j.1365-263x.1999.00145.x
Subject(s) - molar , medicine , permanent teeth , dentistry , crown (dentistry) , tooth eruption , orthodontics , mandibular second molar , radiography , cusp (singularity) , surgery , geometry , mathematics
Summary.Objective . Delayed eruption of the first permanent molar (M1) is a relatively rare finding. This report describes the occurrence of delayed development and eruption of a single M1 in Japanese child patients. Design . Cases were identified by surveying 353 orthopantomograms taken of child patients attending a Dental Hospital. Dental age, crown morphology and the presence of third permanent molars (M3) were determined from radiographs and clinical examination. Setting . Osaka University Dental Hospital in Japan. Results . Nine cases were identified from radiographs. The occlusal morphology of the affected molars showed a reduction of the distolingual cusp. Dental ages correlated more closely to chronological ages when the affected teeth were assumed to be second permanent molars (M2) than they did when the teeth were assumed to be M1. M3 proximate to the affected molar was congenitally absent in the orthopantomograms of all affected subjects. Conclusions . It is suggested that in the cases seen here the affected teeth were likely to have been second permanent molars that had migrated mesially in association with the congenital absence of M1, although congenital absence of M1 has been reported to be extremely rare.