Scandcleft randomized trials of primary surgery for unilateral cleft lip and palate: occlusion in 8-year-olds according to the Modified Huddart and Bodenham index

Background: The Scandcleft international multicenter study is a prospective clinical trial of the long-term outcome after four different surgical protocols for palatal closure in patients born with unilateral cleft lip and palate (UCLP). This paper is one of a series of follow-up studies in 8-year olds.

Objectives: To evaluate the dental occlusion of 8-year-old patients after four different protocols of primary surgery for UCLP.

Trial design: Ten cleft centres in five countries tested three different surgical procedures for primary palatal repair in three parallel trials (Arms B, C, and D) against a common procedure (Arm A).

Methods: Initially 448 children born with non-syndromic UCLP were included in the project. At 8 years of age, 428 children remained in the study. Dental casts of 411 patients (270 boys, 141 girls), mean age 8.1 years (range 7.0-10.0) were taken. The casts were blindly assessed with the Modified Huddart and Bodenham (MHB) index by four orthodontists. The main outcome measures were anterior (+2 to -6) and posterior (0 to -8) mean scores. Comparisons were made with previous data in 5-year-olds.

Results: The inter- and intra-examiner reliability was good to excellent (0.75-0.90; 0.73-0.97), respectively. The mean total scores varied from -7.09 (Trial 2C) to -10.13 (Trial 3D). The mean anterior scores varied from -1.75 (Trial 2C) to -3.18 (Trial 1A). The mean posterior cleft-side scores varied from -4.32 (Trial 1B) to -5.21 (Trial 3D) and the mean non-cleft-side scores varied from -0.88 (Trial 2C) to -2.40 (Trial 3A). No significant differences were found within the trials. A significant difference was found between Trials 2 and 3 (Arm C/D) for the total score (P = 0.004).

Conclusions: There was no evidence of clinically significant differences in occlusion between the two surgical methods in each trial or between the trials. All mean scores showed more negative values in 8-year-olds compared with previously reported values in 5-year-olds.

Trial registration: ISRCTN29932826.