Dental arch relationship outcomes for children with complete unilateral and complete bilateral cleft lip and palate in New Zealand

Objectives: To evaluate dental arch relationships of patients with complete unilateral and complete bilateral cleft lip and palate (CUCLP/CBCLP) in New Zealand. Setting and sample population: Retrospective nationwide observational outcomes study involving 100 CUCLP and 32 CBCLP non-syndromic patients. Material and methods: Four calibrated assessors, blinded to the origin of the randomized digital models, used the GOSLON (UCLP) and the Bauru-BCLP (BCLP) Yardsticks and a 100 mm visual analogue scale (VAS) (UCLP&BCLP) to assess dental arch relationships. Weighted Kappa statistics were used to determine the intra- and inter-rater reliability for the GOSLON/Bauru-BCLP Yardsticks and correlations for the VAS. Results: Intra-rater reliability ranged from 0.57 to 0.88 (GOSLON), 0.62-0.84 (Bauru-BCLP) and 0.45-0.93 (VAS). Inter-rater reliability ranged from 0.62 to 0.86, (GOSLON), 0.48-0.75 (Bauru-BCLP) and 0.64-0.93 (VAS). Of the 100 CUCLP models, 46% had poor/very poor, 28% fair and 26% had good/very good dental arch relationships. Of the 32 CBCLP models, 37.5% were poor/very poor, 40.6% fair and 21.9% had good/very good dental arch relationships. The mean CUCLP VAS score was 50.5 mm (SD 19.9 mm) whilst the mean CBCLP VAS score was 40.0 mm (SD 22.0 mm) and both showed a strong relationship with their respective Yardstick scorings. Conclusion: The dental arch relationships of children in New Zealand with CUCLP are similar to those centres in the Eurocleft and Americleft studies which had less favourable outcomes. Those with CBCLP are inferior to those reported elsewhere. Continued monitoring will allow for tracking of improvement in outcomes.