Primary dentition occlusion in Chinese, Indian and Malay groups in Malaysia

A survey of the primary occlusion in the three ethnic groups, Chinese, Indians and Malays was carried out in Malaysian preschool children between the ages of 3 to 6 years. The main criteria used in the selection of sample was the presence of only the primary dentition. A wide combination of different types of spacing was found. Approximately one third of the cases had incisor spacing and primate spacing in both arches. The occurrence of spacing mesial and distal to canines was just as common as the primate spacing. Chinese and Malay had almost similar distribution of different types of occlusion, whilst the Indians had a higher incidence of Class II malocclusion. An average of 2 4% of the sample had posterior crossbite. Rotation of the incisors formed an average of 17 79% of the cases, with significantly more rotation of the lower arch. The most common rotated teeth were the bilateral mesiolabial rotation of the lower central incisors. Where the rotation of the unilateral lateral incisor was present it was in the distolabial direction.