Scandcleft randomized trials of primary surgery for unilateral cleft lip and palate. Dental arch relationships in 8 year-olds

Background and trial design: The Scandcleft intercentre study evaluates the outcomes of four surgical protocols for treatment of children with unilateral cleft lip and palate (UCLP). Originally 10 cleft centres in Denmark, Finland, Norway, Sweden, and the UK participated in a set of three randomized trials of primary surgery. Three groups of centres (Trials 1, 2, and 3) tested their traditional local surgical protocols (Arms B, C, and D) against a common protocol (Arm A).

Objectives: To evaluate dental arch relationships at age 8 years after four different protocols of primary surgery for UCLP. These results are secondary outcomes of the overall trial.

Methods: Study models of 411 children (270 boys, 141 girls) with non-syndromic UCLP at a mean age of 8.1 (range 7.0-10.0) years were available. Dental arch relationships were analysed using the GOSLON Yardstick by a blinded panel of 11 orthodontists. To assess reliability, Kappa statistics were calculated. The trials were tested statistically with t-tests.

Results: Comparisons within each trial showed no statistically significant differences in the mean 8-year index scores or their distributions between the common protocol and the local team protocol. The mean index scores were Trial 1: Arm A 3.03, Arm B 2.82, Trial 2: Arm A 2.78, Arm C 2.64, and Trial 3: Arm A 3.06, Arm D 3.08. Comparisons between the trials detected a significantly (P < 0.005) better mean index score Trial 2 Arm C than in Trial 3 Arm D. The intra- and inter-rater reliabilities were acceptable.

Conclusion: The results of these three trials do not provide evidence that one surgical protocol is better than the others.

Trial registration: ISRCTN29932826.