Treatment outcome in unilateral cleft lip and palate evaluated with the GOSLON yardstick: a meta-analysis of 1236 patients.

Background: The goal of this study was to assess determinants for treatment outcome in unilateral cleft lip and palate, evaluated according to the Great Ormond Street London and Oslo (GOSLON) Yardstick and 5-year-index ratings by means of a meta-analysis.
Methods: Multiple databases were searched for publications in which patient groups were evaluated by GOSLON ranking or the GOSLON-like 5-year index. From the 15 selected publications, the following background variables could be extracted and were evaluated as determinants for treatment outcome in unilateral cleft lip and palate: year of birth, average age of the patient at the time of GOSLON classification, racial background, presence of Simonart's band, infant orthopedics, palatal closure before the age of 3 versus palatal closure at a later age, bone graft, and number of surgeons.
Results: The total number of patients included in the meta-analysis was 1236. Patients whose soft and hard palate were closed before the age of 3 presented significantly poorer (p = 0.003) GOSLON scores (mean score, 2.9; SD 0.4) than patients whose palate was closed at a later age (mean GOSLON score, 2.3; SD 0.2).
Conclusions: Delayed palatal closure generally results in better dental arch relationships than early palatal closure. Well-designed, randomized clinical trials are required for further investigation of the optimal timing for palatal closure.