Abstract
Schedules based on tooth development are useful in age assessments of children,but in early infancy they are based on only a few studies. The radiographicappearance of the mandibular symphysis during the first postnatal months hasnot gained attention. The present study describes the formation of teeth andthe development of fusion between the mandibular halves during the first fivepostnatal months, as seen in panoramic tomograms taken in medicolegal autopsiesof 29 ethnic Finns, 19 boys and 10 girls, at the Department of Forensic Medicine,University of Helsinki. In the majority of the infants, the criteria of suddeninfant death (SID) were fulfilled. The stages of tooth formation used werethose applied by Moorrees et al. (5) with one modification (Nystrom et al.(7)).
Mineralization of all primary teeth proceeded rapidly during the firstpostnatal months, the change being on average two developmental stages infour months. Considerable variation in tooth development existed in infancy.The mandibular halves were separated at birth. Complete fusion had occurredin the majority of infants aged four months, and the tomograms of the remaininginfants showed a thin vertical line in a part of the symphysis. The markedchanges, which during the first postnatal months occur in the radiographicalappearance of the mandibular symphysis, and in the formation of primary teeth,provide valuable information for age assessments of infants.
