Genetics of the dentofacial variation in human malocclusion

Abstract

Malocclusions affect individuals worldwide, resulting in compromised function and esthetics. Understanding the etiological factors contributing to the variation in dentofacial morphology associated with malocclusions is the key to develop novel treatment approaches. Advances in dentofacial phenotyping, which is the comprehensive characterization of hard and soft tissue variation in the craniofacial complex, together with the acquisition of large-scale genomic data have started to unravel genetic mechanisms underlying facial variation. Knowledge on the genetics of human malocclusion is limited even though results attained thus far are encouraging, with promising opportunities for future research. This review summarizes the most common dentofacial variations associated with malocclusions and reviews the current knowledge of the roles of genes in the development of malocclusions. Lastly, this review will describe ways to advance malocclusion research, following examples from the expanding fields of phenomics and genomic medicine, which aim to better patient outcomes.

Keywords: candidate genes; cephalometry; craniofacial; genetics; genomic medicine; genotype-phenotype correlation; phenomics.

Fig. 1

Individuals in the extreme opposite ends for the first three principal components explaining about 50% of the total variation in Class II malocclusion. PC1 refers to variation in the inclination of the mandibular plane angle. PC2 depicts maxillary incisor angulation. PC3 refers to the mandibular AP and vertical length and posterior facial height.

Fig. 2

Cluster analyses for Class II malocclusion showing dentofacial features of cluster centroids and their main features. Pro, profile; Cb, cranial base; Mx, maxilla; Md, mandible; Vert, vertical; U1, upper incisor; L1, lower incisor; St, soft tissue.

Fig. 3

Individuals in the extreme opposite ends for the first three principal components explaining about 54% of the total variation in Class III malocclusion. PC1 shows the anteroposterior position of the mandible in relationship to the cranial base. PC2 depicts the maxillomandibular horizontal and vertical size discrepancies. PC3 refers to the lower incisor and lower lip variation.

Fig. 4

Cluster analyses for Class III malocclusion showing dentofacial features of cluster centroids and their main features. Pro, profile; Cb, cranial base; Mx, maxilla; Md, mandible; Vert, vertical; U1, upper incisor; L1, lower incisor; St, soft tissue.