White spot lesions after fixed appliance treatment—Can we expect spontaneous long-term (≥15 years) improvement?

Abstract

Summary Objective To investigate the extent to which post-orthodontic white spot lesions (WSLs) change in appearance over a period of ≥15 years and whether an association with caries data exists. Subjects and Methods Seventy-two patients treated with a Herbst-Multibracket appliance at age 14.0 ± 2.7 years for 20.1 ± 5.1 months who attended a recall 18.3 ± 2.9 years post-treatment. Post-treatment (T1) intraoral photographs were assessed by a panel of five dentists using a modified version of the WSL-Index by Gorelick. For affected incisors, photographs from before treatment (T0) and recall (T3) were evaluated. In addition, the WSL-Change Index by Pancherz and Muehlich was assessed for all adequately visible incisors considering T1, T2 (if available), and T3. Radiographic (T0, T1, and T2—if available) and clinical (T3) MFT data were used. Results 37.5% of the patients exhibited WSLs on ≥ 1 incisor at T1; in total, 81 incisors (14.9%) were affected. At T3, 48% of the WSLs had improved. The modified WSL-Index decreased from 1.2 ± 0.4 to 0.8 ± 0.6 (P < .001), with a score 0 in 28% of the previously affected incisors. When comparing T2 vs. T3, additional improvement after T2 occurred in 11% of the teeth. While no difference existed at T0, the MFT values at T1, T2, and T3 were higher (P ≤ .05) in patients with WSLs at T1 than in those without. Limitations The homogeneity of the subjects was limited and no patient-reported outcome was assessed. Conclusions Long-term, post-orthodontic WSLs showed spontaneous full recovery in 28% and improvement in 48% of the teeth. Patients affected with WSLs exhibited higher post-treatment MFT values.