Dental Arch Dimensions and Form in a Sudanese Sample

The aim of this study is to determine the dental arch dimensions (width and length) and form in a group of a Sudanese sample population.

The size and shape of dental arches have significant implication in orthodontic diagnosis and treatment planning as it affects the space available, dental esthetics and stability of the occlusion.

This study is a biometric analysis of dental casts of 50 adult Sudanese dental students (20 males, 30 females) aged between 19 to 22 years with normal occlusion. The study was conducted at the orthodontic clinics, Faculty of Dentistry, University of Khartoum. Each student was interviewed and written consent was given. The inclusion criteria were: complete permanent dentition fully erupted to the occlusal plane, no proximal caries or restorations, no attrition or dental anomalies, no extractions, no previous or ongoing orthodontic treatment and no fractures or jaw surgeries. Paired-test, ANOVA test, and Pearson's correlation were used for statistical analysis with a p-value set at 0.05.

The result showed normal occlusion is higher in males than in females. Upper arch dimensions (width and length) found to be higher in males than females, inter canine width (ICW), males 36, and females 34.45; interpremolar width (IPmW) males 48.08, females 47.58; inter-molar width (IMW) males 53.04, females 52.4; the length for males 37.98 and for females was 37.09. Comparison of Lower arch dimensions between males and females showed ICW (27.08 and 26.86); IPmW (40.97 and 39.67); IMW (45.61 and 45.69); depth was (33.91 and 33.91) consequently. The ovoid-shaped arch form was more common in both genders.

Length dimension showed the highest value with square arch form. The width dimensions increase with little change in the inter-canine region but appreciably more in the distal part of the arch. Men have a more massive arch form than females. The ovoid arch form dominates in the Sudanese population.

Knowledge of arch dimensions that are associated with normal occlusion is helpful in determining treatment goals and proper diagnosis and treatment plan by choosing the right arch form for each race.