Effects of previous orthodontic treatment on periodontal status of patients in long-term supportive periodontal care

Abstract Background While many German children and young adults receive orthodontic treatment (OTx), the number of patients requiring periodontal treatment is increasing due to demographic changes. Investigating the long-term effects of orthodontic treatment on periodontal health, particularly in patients developing periodontitis, is therefore of public health interest. Primary aim was to evaluate whether an anamnestic history of OTx affects the progression of periodontal parameters over a ten-year period of supportive periodontal care (SPC). Additionally, the study aimed to determine whether orthodontic treatment need in SPC patients correlates with periodontal and dental parameters change during the preceding ten years of SPC. Methods Sixty periodontitis patients with ten years (± six months) of SPC received digital intraoral scans during cross-sectional SPC follow-up examination (T1). Patients’ previous orthodontic treatment (POT) or no treatment (NOT) was recorded. The Index of Orthodontic Treatment Need (IOTN) at T1 was assessed. Dental and periodontal parameters were recorded and compared with retrospective data from ten years (± six months) earlier (T0). The association between changes in clinical attachment levels (CAL T0-T1) and treatment group (POT/NOT) was analysed (multiple linear regression). Spearman correlation between IOTN and clinical parameters change was assessed. Results The change in parameters from T0 to T1 was as follows (POT: n = 24 patients, NOT: n = 36 patients): Mean tooth loss: 0.92 ± 1.74 vs. 0.64 ± 0.90; Mean probing pocket depth: -0.03 ± 0.33 mm vs. 0.05 ± 0.51 mm; Mean CAL: 0.11 ± 0.59 mm vs. 0.09 ± 0.66 mm. No association was found between CAL change and treatment group. Only a negligible correlation between IOTN and changes in dental, periodontal, and oral hygiene parameters was found. Conclusions Patients with successfully treated periodontitis, both with and without a history of orthodontic treatment, show a high level of periodontal stability during long-term SPC and comparable orthodontic conditions. Trial registration Clinical trial registration number on the German clinical trials register: DRKS00011316 (Registration date 17th November 2016).