Mandibular Arch Forms and Malocclusion among Hausa Adults in Northern Nigeria: A Preliminary Survey

Abstract

Background: Data on prevalent arch forms and their relationship with malocclusion may guide treatment. This study sought to relate mandibular arch-forms to sagittal relationships and certain malocclusion features among an adult Hausa cohort in Northwestern Nigeria.

Methods: Consenting adults who met inclusion criteria were assessed. Their mandibular arch forms, sagittal relationships, and presence of crowding or spacing were recorded from gypsum models.

Descriptive statistics were performed. Chi2 and Fischer's Exact tests were used to test for associations. The strengths of associations were tested with the Phi coefficient and Cramer's Vtests. The level of statistical significance was set at p ? 0.05

Results: Ahundred and fifty-eight adults with a male: female ratio of 1.5: 1; aged between 18 and 58 years (26.1 ± 8.2) were assessed. The ovoid arch form (78.5%) was predominant, while the tapered (6.3%) was the least. Angles Class I (90.5%) was predominant while the Canine relationship was of a similar pattern. There were 43(27.2%) participants with anterior crowding, 11(7%) with posterior crowding, 12(7.6%) with anterior spacing and 2(1.3%) with posterior spacing.

Anterior crowding (p=0.01) and posterior crowding (p=0.001) were associated with females. Anterior crowding (p=0.04) was associated with incisor class III. All arch forms were mostly with Angles Class I relationship (p=0.02) and Class I Canine relationship (p<0.001). Posterior crowding was associated with tapering arches (p=0.04), while posterior spacing was associated with tapering and square arches (p=0.02).

Conclusion:There were discernible associations between mandibular arch forms, sagittal relationships and the presence of crowding or spacing.