Department of Orthodontics, School of Dentistry, Iwate Medical University
Abstract
Using photodensitometry for 47 patients who had congenitally missing permanent teeth, excluding for third molars, bone mineral content (BMC), determined via dental radiographs, was compared with a control group of 43 patients who have all their teeth. In addition, bone age was determined by hand-wrist radiographs using the TW 2 method, and the differences of skeletal maturation between both groups were evaluated. The results are as follows : 1. The average BMC was significantly lower in the group missing teeth than in the control group both for young males (aged 7-15 years old) and young females (aged 6-15 years old). 2. The BMC in the group of people missing more than three teeth was significantly lower than those in the groups of people missing one or two teeth. 3. Regarding the average BMC by the location of missing teeth : The maxillo-mandibular group had the lowest BMC, followed by the second lowest mandible group and finally the maxillary group. By type of missing teeth : The molar, which contained at least one molar and anterior-premolar teeth group, had the lowest BMC. Second lowest was the group missing premolar followed by the group missing anterior. 4. In the groups with missing teeth, bone age was lower by 0.97 years in young males compared to 1.18 years in young females. These results show delayed skeletal maturation. In conclusion, this study clearly indicates that compared to the control group BMC is lower, and skeletal maturity has a tendency to be delayed in children with missing teeth. These results can assist planning of orthodontic treatment to patients with congenitally missing teeth
