Abstract
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 children with fused deciduous teeth, and the use of study casts from 37 people in Hellman Dental ages of stage 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 AB fused 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 of these 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 maxillary AB teeth. Of the 46 cases of mandibular AB fused teeth, successional permanent teeth deficiencies were 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 were observed in 29 cases, and fusion of successional permanent teeth was observed in 7 cases.
4) Concerning the terminal planes, we were unable to observe any major differences between sides with fused teeth, and sides without. Tooth alignments where maxillary and mandibular AB were fused teeth, were of the vertical types, but the mesial types were more numerous in tooth alignments with BC 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 alignments with 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 cases where fused teeth were found to exist in the mandibular, and this trend was particularly conspicuous for tooth alignments where BC were fused teeth. A strong tendency towards a shortening of the lower dental arch length was also observed when fused teeth existed on both the left and right sides.
