RESUMEN
UNLABELLED: The standards or proportions commonly used as guides for the selection of maxillary anterior teeth for a removable prosthesis have been developed mainly on Caucasian populations with normal ridge relationships. PURPOSE: This study was conducted to determine the canine position in relation to commissures in different maxillomandibular relationships among Egyptian and Saudi populations. MATERIAL AND METHODS: Two hundred subjects participated in this study, 100 from each population. The location of the corners of the mouth for each subject was marked on the buccal surface of a screen previously constructed on the maxillary cast and transferred to the casts. The distances between the corners of the mouth and the canines' distal aspect were measured on the casts. The measurements were subdivided according to their relation to the commissures: at commissures, medial to commissures, or distal to commissures. The data were then statistically analyzed. RESULTS: Coincidence between the canine distal aspects and commissures was recorded only within 8% of both Egyptian and Saudi populations. Additionally, within the Egyptian population, coincidence was recorded only at Class-I ridge relationship. CONCLUSION: Commissures are not a reliable landmark for determination of the distal aspect of the canine distal aspects of both Egyptian and Saudi populations.