Analysis of Malay Arch Width and Anthropometric Correlations

The objectives of the study were to determine the normal dental arch width of Malays, their correlation with the facial framework and the ideal size of orthodontic impression trays that fit the dental arch. Eighteen adult Malays with normal Class I occlusion were evaluated. Arch width was measured on each subject’s dental cast. Direct anthropometric measurements were taken for 8 facial landmarks. Orthodontic impression trays were tried on each subject’s dental cast to determine the best fitting tray. Correlations analysis was made between the arch widths and the best fitting impression trays used and also with various craniofacial anthropometric measurements. The eight measurements from the craniofacial region were compared with the maxillary and mandibular intercanine, interpremolar and intermolar widths. In the maxillary arch, there were significant correlation between the face width and the interpremolar and intermolar widths respectively, while in the mandibular arch, significant correlations were noted between the mandible depth and the interpremolar and intermolar widths respectively. The most common fitting impression tray was size 6 for the upper jaw and size 5 for the lower jaw. There was a significant correlation between the maxillary intercanine width and the size of the impression trays. The significant correlation between upper and lower interpremolar and intermolar widths and the anthropometric measurements of this Malay population may assist in predicting arch expansion to achieve Class 1 occlusion during orthodontic or maxillofacial surgical treatment. The significant correlation between the upper intercanine width and the size of impression tray can be a useful parameter when determining the size of impression tray.