The Impact of Premature Extraction of Primary Teeth on Orthodontic Need in a Longitudinal Birth Cohort

Background: VI Abstract Extraction of primary teeth is common. The impact of premature extraction of primary teeth (PEPT) is uncertain on the future need for orthodontic treatment and oral health-related quality of life (OH-RQoL). Aim: To investigate the association between PEPT and orthodontic need based on the Index of Orthodontic Treatment Need (IOTN) and OH-RQoL based on the short form of the Child Oral Health Impact Profile (COHIP-SF 19) Methods: This was a cross-sectional study that recruited children aged 7-11 years participating in the Born in Bradford (BiB) birth cohort in England. An earlier dental data linkage study had identified BiB children who received PEPT under general anaesthetic (exposures). BiB children who had PEPT under local anaesthetic were identified during data collection. Trained examiners collected data from participants with and without PEPT (controls) in consented primary schools in Bradford. Data collected included dental examination, extra-oral and intra-oral photographs, and alginate impressions. Participants completed the COHIP-SF 19 questionnaire to assess OH-RQoL. A blinded expert panel, consisting of three specialist orthodontists, independently assessed the records for orthodontic need using the Dental Health Component of the IOTN. Descriptive statistics using means, standard deviations or medians, interquartile ranges were calculated. The proportion of VII participants assessed in need for orthodontic treatment and the odds ratio were calculated. Differences in COHIP-SF 19 scores by group were assessed using the Mann-Whitney U test. Results: Three hundred seventy-four participants were recruited with 82 participants with PEPT and 292 without PEPT. The proportion of participants with PEPT who were assessed in need for orthodontic treatment was 69.2% (n=54/78) compared to 40.6% of participants without PEPT (n=99/244). PEPT was significantly associated with an increased need for orthodontic treatment (OR=3.3, 95% CI=1.91-5.68, P<0.001). The difference in the median total COHIP-SF 19 scores between participants with PEPT (57, IQR 52-60) and without PEPT (58, IQR 51-64) was not statistically significant. Conclusion: PEPT was strongly associated with an increased need for orthodontic treatment when assessed in the mixed dentition, using the IOTN-DHC. No impact of PEPT on the OH-RQoL was found.