Comparison of the malocclusion and orthodontic treatment needs of Down syndrome and non-syndromic subjects by using the dental aesthetics index.

OBJECTIVE: To evaluate the prevalence and significance of the malocclusion traits and orthodontic treatment needs of Down syndrome (DS) subjects with matched non-syndromic (NS) controls. METHODOLOGY: This cross-sectional study involved 222 subjects (50% DS, 50% NS) who were matched by gender and age. The casts were digitized into three-dimensional images. These images were used alongside the ten occlusal characteristics of the Dental Aesthetic Index (DAI) to determine malocclusion severity and the need for orthodontic treatment. RESULTS: There were 58 (52.3%) females and 53 (47.7%) males with a mean age of 18.4 ± 8.4 years in both groups. The most common and significant (p < .05) malocclusion traits among the DS subjects were missing teeth (56.2%), incisal spacing segments (73.0%), anterior maxillary irregularity (95.5%), mandibular overjet (36.0%), and full cusp deviation of the molar relationship (61.3%). On the other hand, increased maxillary overjet (69.3%) is a more significant (p < .05) trait amongst NS subjects. There were 85 (76.6%) DS subjects who presented severe malocclusion, which implies a highly orthodontic treatment need (DAI > 30). The DS showed some impact of malocclusion traits components of the DAI. CONCLUSION: The occurrence of malocclusion was higher in DS, implying a higher need for orthodontic treatments than for NS subjects.