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.