lower facial height and lip protrusion. This can be linked to lower maxillary to mandibular plane angles. A more acute mandibular angle and flatter chin may develop as a result. These characteristics become more prominent as the condition becomes progressively severe, particularly when more than one tooth is missing. Other dental and radiographic features Data derived from principal component analysis of radiographic images show that children with mild hypodontia may display significant increase of the interincisal angle and decrease in the maxillary and mandibular incisor angles. Cephalometric tracing is commonly used to study a patient's dentofacial proportions in the craniofacial complex. This can aid in predicting growth changes, allowing dentists, especially orthodontists, to develop a suitable treatment plan. Coupled with that, findings consistent among individuals include: Anterior hypodontia associated with hyper divergent craniofacial pattern; A tendency toward a class III malocclusion identified in maxillary hypodontia, and; Reduced lower posterior facial height in children with posterior and mandibular hypodontia. Associated anomalies Reduction in coronal or radical dimensions Retained primary teeth Ectopic canine eruption Abnormal morphology such as peg-shaped maxillary lateral incisors and taurodontism, characterized by an enlarged tooth body and roots that are reduced in size Extracted teeth Cause Several theories regarding the aetiology of hypodontia have been proposed in existing literature. There have been various theories mostly looking into genetic and environmental aspects and how they may both be involved. However, the exact cause remains unclear. The extent of individual influences of genetic and environmental factors is still widely debated. Theories regarding the mechanism through which hypodontia occurs can be categorised into evolutional or anatomical. Preliminary studies focused on an evolutionary approach which suggested shortening of the intermaxillary complex and thus shorter arches may contribute to a decrease in number of teeth. This was also suggested in 1945 by Dahlberg using Butler's Field Theory that focused on evolution and development of mammalian teeth into human dentition in an attempt to analyse different of agenesis. In each jaw, four morphological sites were identified (incisors, canines, premolars and molars). The tooth at the end of each region was less genetically stable and hence more prone to absence. In contrast, the tooth most mesial in each region seemed to be more genetically stable. A subsequent theory hypothesised the teeth at the end of each region were possibly "vestigial bodies" that became obsolete during the evolutionary process. At present, it has been theorised that