Mesiodistal root angulation of permanent teeth in children with mixed dentition and normal occlusion

Objective

There is little information regarding the mesiodistal angulation of permanentteeth in mixed dentition. The aim of this study was to evaluate mesiodistal rootangulation of permanent incisors, canines and first molars of 100 Brazilianchildren, using a new horizontal reference plane based on the midpoint of theintercuspation of primary canines and permanent first molars in panoramicradiographs during the mixed-dentition phase.

Material and methods

Children were equally divided between the genders with a mean age of 8.9 years(SD=0.76), normal occlusion and no eruptive disturbances.

Results

The angulation of the permanent maxillary first molars was close to the vertical,whereas the mandibular molars presented approximately 25 degrees of distal rootangulation. The maxillary canines were the most distally angulated teeth, whereasthe permanent mandibular canines were vertically positioned. The evaluation of theanterior maxillary area showed vertical position of permanent lateral, and centralincisors with a slight distal angulation, whereas the permanent mandibularincisors tended to a mesial radicular convergence.

Conclusions

The proposed reference line could be useful in mixed dentition root angulationevaluation; there was a slight asymmetry in the mesiodistal angulation amonghomologous teeth, and also a small variation between the male and the femalegroups, but no difference between 8-and 10-year-old children.