Unerupted second primary molars: report of two cases.

Two cases with an unerupted primary left mandibular second molar are described. second premolar was congenitally missing, in the other the unerupted primary molar was positioned inferiorly and lingually to its permanent successor. Unerupted primary molars should be extracted, but the time of extraction should be defined carefully by taking into consideration the development of the succedaneous premolar and the space relations in the permanent dentition.