Objective: The aim of this study was to evaluate quantitatively the effectiveness and feasibility of the modified supracrestal fiberotomy (MSF) and the contact point reproximation (CPR) in decreasing the relapse of anterior segments rotating and/or crowding after orthodontic treatment.
Methods: A total of 129 patients with crowding and/or rotated anterior teeth were selected for this study, and the average age was 13.07 years (54 males, 75 females). The modified supracrestal fiberotomy was performed on the anterior segments of patients in the experimental group (48 cases). After the anterior teeth were aligned, 23 of the 48 cases received a further treatment of the contact point reproximation on the anterior segments (the subgroup of MSF + CPR), and the other 25 subjects did not receive this treatment (the subgroup of MSF). The control group consisted of 81 cases. All cases wore Hawley retainers for 1.8 to 2.3 years, and all the patients were revisited 2.4 years postretention. The maxillary and mandibular dental models of all the patients were taken before treatment (T1), at the end of the treatment (T2) and 2.4 years postretention (T3).
Results: The relapse rate in the experimental group [(T3-T2)/T1 x 100%] was 21.6%, lower than that in the control group (P < 0.001). The relapse rate of mandible in the subgroup of MSF + CPR was 6.56% lower than that of the subgroup of MSF (P < 0.05). But the relapse rate of maxillary in the subgroups of MSF + CPR was similar as that of the subgroup of MSF (P > 0.05).
Conclusion: The modified supracrestal fiberotomy can effectively alleviate relapse after orthodontic treatment of the crowding and/or rotation of anterior teeth. The treatment combining MSF and CPR can help maintain the stability of post-retention of mandibular anterior teeth.