['To evaluate if prematurely born children have higher prevalence of malocclusion traits and greater orthodontic treatment need than matched full-term born controls.', 'Seventy-three preterm children were selected from the Medical Birth Register and divided into two subgroups according to their gestational age. One group consisted of 37 very preterm children (VPT), born in gestational week 29-32, and the other of 36 extremely preterm children (EPT), born before the 29th gestational week. The subjects were compared with a control group of 41 full-term children, who were matched for sex, age, and nationality. Data from clinical examinations, study casts, and panoramic radiographs were used to determine malocclusion traits. The dental health component of the index of orthodontic treatment need (IOTN) was used to rank the treatment need.', 'Two or more malocclusion traits occurred significantly more often among EPT (83.3%) and VPT children (73.0%), compared with the full-term children (51.2%). Significantly higher prevalence of deep bites and was found in EPT and VPT groups compared with the full-term control group. Deep bite was the most common malocclusion trait in the EPT and VPT group. Higher orthodontic treatment need was found for the preterm children but no differences in prevalence of malocclusion traits and treatment need were found between VPT and EPT children.'] Does malocclusion traits and orthodontic treatment need in prematurely born children?