Classification and sequelae of arrested eruption of primary molars.
OBJECTIVE
The aim of this study was to classify early arrested eruption of primary molars and to analyse and explain the sequelae for the surrounding alveolar bone and the succeeding premolar.


METHODS
The position of the arrested primary molars in the mandible, the height of the local alveolar bone, and the morphology and location of the succeeding premolar were evaluated on radiographs from 29 children.


RESULTS
Four groups of arrest from mild to severe with regards to infra-position were categorized (Groups I-IV). Mean ages at the time of referral decreased from Groups I (8 years, 10 months) to Group IV (5 years, 9 months). SEQUELAE: (i) Reduction of alveolar bone height (Groups I-III); (ii) delayed maturity of the succeeding premolar (two-thirds of the cases); (iii) malformation of the succeeding premolar (mainly Groups III and IV); and (iv) ectopically located premolar occlusal to the retained molar (Group IV).


CONCLUSIONS
The deeper in the alveolar process a primary molar is retained, the earlier the disturbance in the eruption has occurred, and the greater is the risk of the permanent tooth germ being malformed and malpositioned. It is estimated that the earliest occurrences of arrested eruption of primary molars supposedly occur before the age of 3.
Kjaer
Inger
I
Department of Orthodontics, School of Dentistry, University of Copenhagen, Copenhagen, Denmark. ik@odont.ku.dk
Fink-Jensen
Merete
M
Andreasen
Jens Ove
JO
D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000473:pathology; D001641:Bicuspid / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D006801:Humans; D008963:Molar / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011859:Radiography; D014078:Tooth Eruption / Q000502:physiology*; D014094:Tooth, Deciduous / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014097:Tooth, Unerupted / Q000145:classification / Q000000981:diagnostic imaging* / Q000209:etiology