ObjectiveTo evaluate the prevalence and significance of the malocclusion traits and orthodontic treatment needs of Down syndrome (DS) subjects with matched non‐syndromic (NS) controls.MethodologyThis 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.ResultsThere 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.ConclusionThe occurrence of malocclusion was higher in DS, implying a higher need for orthodontic treatments than for NS subjects.