A case-control study of dental development in Hypodontic and Hyperdontic children.

PURPOSE: The purpose of this study was to investigate the rate of dental development in children with nonsyndromic hypodontia and nonsyndromic hyperdontia compared to age- and gender-matched controls. METHODS: Dental age assessment was performed using orthopantomograms on 115 children (63 girls, 52 boys) with hypodontia and 61 children (22 girls, 39 boys) with hyperdontia and compared with 176 normal controls, case-matched for gender and age. RESULTS: Both girls and boys with hypodontia showed a significant delay in dental development compared to case controls. The mean differences between dental age and chronological age in hypodontia girls and boys were -0.1+/-1.5 years and -0.1+/-1.2 years, respectively, compared to 1.0+/-1.0 years and 0.8+/-0.8 years in the case controls, respectively (P<.001 for both boys and girls). The delay in dental development was accentuated during puberty. By contrast, no significant differences were observed between hyperdontic children and case controls. CONCLUSIONS: Nonsyndromic hypodontia children experience delayed dental development, whereas nonsyndromic hyperdontia children have similar rotes of dental development compared to normal children. These findings have implications for management of dental growth and development in children with agenesis of the teeth and supernumerary teeth.

Taurodontism in children with hypodontia and supernumerary teeth: a case control study.

PURPOSE: The aim of the present investigation was to compare the prevalence of taurodontism in the permanent mandibular first molars of nonsyndromic children with hypodontia and supernumerary teeth with age- and gender-matched controls. METHODS: The crown-body root ratios of the permanent first molars were determined from orthopantomograms of 83 children with hypodontia (> or =1 missing teeth) and 37 children with supernumerary teeth (> or =1 extra teeth) compared with normal case controls. RESULTS: In children with hypodontia, only girls showed a significantly higher tendency for taurodontism compared to case controls (P=.003), while boys with hypodontia showed a similar prevalence of taurodontism as controls (P=.83). Children with multiple missing teeth were significantly more susceptible to taurodontism than children with a single missing tooth (P=.004). By contrast, the prevalence of taurodontism in children with supernumerary teeth was not significantly different from that of controls. CONCLUSIONS: Compared to normal case controls, children with nonsyndromic hypodontia are more likely to show taurodontism of the permanent first molar teeth whereas children with nonsyndromic supernumerary teeth are not.