Evaluation of maxillary and mandibular arch forms in an Italian adolescents sample with normocclusion

Aim The purpose of this restrospective study was to evaluate the maxillary and mandibular arch forms in an Italian adolescents sample with normocclusion. Materials and methods The dental casts of 106 adolescents (48 females and 58 males; mean age: 14 ± 0.5 years old) were included. Twelve clinical bracket points were measured for each cast and six parameters were evaluated: intercanine and intermolar width, canine and molar depth, canine and molar ratio. Moreover, each cast was classified into tapered, ovoid, or square form. Chi-square test and odds ratio for categorical variables and Student’s T-test for continuous parameters were adopted and the level of significance was set at p< 0.05. Results A similar ovoid (43.4%) and tapered (46.2%) arch form was found, while the square form was the rarest (10.4%). Males exhibit higher dental arch values in comparison to females (p< 0.05). Slight variations in maxillary and mandibular intercanine width and canine ratio were observed, while higher variations were seen in the maxillary intermolar width, in the maxillary and mandibular canine and molar depth. Conclusion These results are relevant since individualisation of orthodontic therapy leads to more effective treatment by working within the subject’s natural dental arch shape.