Tooth agenesis: dental anomalies and effects on dentofacial structures

This study evaluate the frequence, distribuition and the prevalence of tooth agenesis, excluding the third molar, in relation to each tooth; furthermore it aims to determine a relationship between agenesis and other dental anomalies and possible effects on skeletal growth patterns. 500 Italian patients, 257 girls and 243 boys were examinated. From clinical examinations, photographs, various radiographs and cranio-facial measurements obtained from lateral cephalograms, the following results were noted: 5,2% of the patients had congenitally missing teeth, the mandibular second premolar was the most frequently absent tooth, that occurred with a prevalence of 1,4-1,8%. The most commonly observed associated dental anomaly was hypodontia of other teeth, found in more than 50% of subject with agenesis. We stated that the differences observed between subjects with agenesis and the control group, were related much more with dental anomalies than with skeletal factors. In subjects with agenesis, the SNB and Z angles decreased and the ANB increased compared with the control group.