Aim: This study aimed to use the Index for Preventive and Interceptive Orthodontic Treatment Needs (IPION) in high caries children and to investigate the IPION components that differentiate level of preventive and interceptive orthodontic treatment need (P&I Tx need).
Methods: A sample of 202 children (8-9 years of age) was randomly selected from the schools in urban and rural areas in Songkhla Province, Southern Thailand. Dental models, intra-oral photographs, and the examination of oral function were collected and the P&I Tx need was determined according to IPION. Chi-square or Fisher's exact test were performed to test the difference in proportions of each component of IPION among levels of P&I Tx need.
Results: Almost all children (96.0%) needed preventive and interceptive orthodontic treatment. The characteristics that were significantly different among P&I Tx need groups were primary molar proximal caries, anterior crossbite, lower permanent molar tipping, and abnormal molar relationship (p < 0.05). The major part of the IPION scores in the definite treatment need group came from caries, early loss, and crossbite.
Conclusions: The P&I Tx need in this group of children was very high. Primary molar proximal caries, anterior crossbite, lower permanent molar tipping, and abnormal molar relationship were the dominant factors that indicated P&I Tx need in these children.
Keywords: Caries; Children; IPION; Index; Orthodontic treatment need; Preventive and interceptive.