Prospective Clinical Investigation of Orthodontic Relapse from Gingival Clefts

Background: Orthodontic space closure following premolar extraction may result in gingival cleft formation. This may contribute to orthodontic relapse due to reopening of extraction spaces. Purpose: 1) To see the effects gingival clefts have on relapse and opening of closed extraction spaces after orthodontic treatment. 2) To record any changes in cleft severity that may occur. 3) To evaluate any relationship between gingival phenotype and cleft severity. Methods: Subjects recruited from previous study in which gingival clefts were measured during space closure. The clinical measures included the occurrence and severity of clefts and their relationship to gingival phenotype. Results: Sites with a cleft (N=42) had 42.86% relapse and those without (N=19) had 36.84% relapse. Conclusions: As gingival cleft severity increases, the amount of relapse distance is likely to increase. Patients with a thick gingival phenotype who obtain gingival clefts in extraction sites during orthodontic treatment are more likely to have relapse post-treatment compared to sites which did not develop a gingival cleft.