Résumé
The purpose of this study was to assess the feasibility of the use of Index of Orthodontic Treatment Need (IOTN) on labial segment malocclusion in determining the need for orthodontic treatment among 8 to 10-year old children. Convenient sample of one hundred and six (106) children (54 boys and 52 girls) were examined extra and intra-orally. Their skeletal and dental discrepancies were assessed in all three dimension planes. Any presence of mandibular displacement was identified. The IOTN score was determined for each child. Respectively it was found that 39.6%, 49.1% and 11.3% of the children presented with skeletal Class I, Class II and Class III malocclusion(p<0.05). Inter-arch relationship showed a significant difference of the midline condition of the upper arch and the presence of anterior and posterior crossbite (p<0.05). About 17.8% of the children had increased overjet of more than 6 mm. Increased overbite was seen in 55.7% of the children with 7.6% presenting with palatal contact. There was a higher prevalence (57.5%) of crowding in the mandibular arch, while the maxillary arch had a higher prevalence (62.2%) of spacing. More than half (62.2%) of the children were in need of treatment (IOTN Grade 3, 4 and 5).This study showed a high prevalence of labial segment malocclusion among 8 to 10-year-old children which indicate orthodontic intervention. The IOTN is not a suitable index for mixed dentitions to be used for developing occlusion for the population group.