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Updated: Apr 8, 2026
Systematic Assessment of Mammalian Skull Specimens for Dental and Temporomandibular Joint Pathology
Published on: August 22, 2022
Is arch form influenced by sagittal molar relationship or Bolton tooth-size discrepancy?
Abdullah M Aldrees1, Abdulmajeed M Al-Shujaa2, Mohammad A Alqahtani3
1Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, P.O. Box 60169-38, Riyadh, 11545, Saudi Arabia. amaldrees@ksu.edu.sa.
Background:
Orthodontic patients show high prevalence of tooth-size discrepancy. This study investigates the possible association between arch form, clinically significant tooth-size discrepancy, and sagittal molar relationship.
Methods:
Pretreatment orthodontic casts of 230 Saudi patients were classified into one of three arch form types (tapered, ovoid, and square) using digitally scanned images of the mandibular arches. Bolton ratio was calculated, sagittal molar relationship was defined according to Angle classification, and correlations were analyzed using ANOVA, chi-square, and t-tests.
Results:
No single arch form was significantly more common than the others. Furthermore, no association was observed between the presence of significant Bolton discrepancy and the sagittal molar relationship or arch form. Overall Bolton discrepancy is significantly more prevalent in males.
Conclusions:
Arch form in a Saudi patient group is independent of gender, sagittal molar relationship, and Bolton discrepancy.
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