Predictors for long-term relapse of orthodontic treatment in patients with cleft lip and palate. A clinical follow-up study

Objectives: To identify predictors for long-term relapse of orthodontic therapy in patients with cleft lip and palate (CLP).

Materials and methods: Patients with uni- and bilateral non-syndromal CLP were followed up at least two years after completion of their orthodontic therapy. Plaster casts of the start of treatment (T1), after completion of treatment (T2), and at follow-up (T3) were measured using the modified Huddart Bodenham Index. Characteristics of multidisciplinary therapy were taken from the patient files. Potentially influencing factors of relapse were investigated using logistic regression analyses and Spearman correlations.

Results: In total 58.07% of the included 31 patients showed a stable treatment outcome at follow-up after an average of 6.9 years. Even if relapse occurred, 61.54% of these patients still showed improvement regarding their occlusion compared to baseline. Predictors for the occurrence of relapse were the severity of dysgnathia at baseline (p = 0.039) and the extent of therapeutic change (p = 0.041). The extent of therapeutic change was additionally a predictor for the extent of post-therapeutic relapse (ρ = 0.425; p = 0.019).

Conclusions: Patients with CLP benefit from their orthodontic therapy in the long term despite an increased tendency to relapse.

Clinical relevance: Results of this long-term study could be used to adapt the treatment concept for patients with CLP and reinforce the significance of a patient-centered orthodontic treatment concept for affected patients.