In recent years, there has been a growing interest in adult orthodontics due to increasing aesthetic demands and advancements in treatment modalities. As more adults seek orthodontic treatment, clinicians frequently encounter patients with pre-existing periodontal conditions, highlighting the need to understand the effects of orthodontic tooth movement (OTM) on periodontal tissues. The aim of this study was to evaluate the response of periodontal tissues to OTM, in healthy conditions and after 14 days of ligature-induced periodontitis, by assessing periodontal ligament (PDL) width and the expression of receptor activator of nuclear factor-κB (RANK)-RANK ligand (RANKL)-osteoprotegerin (OPG) in a rat model of experimental periodontitis and orthodontic tooth movement. Experimental periodontitis was induced by ligating the left maxillary second molars (experimental side) of 36 Wistar rats. The maxillary right sides (control sides) were left unligated as positive controls. After 14 days, the ligatures were removed, and orthodontic appliances for mesialization were placed on three maxillary molars combined in one unit and activated. The rats were sacrificed post-activation on days 1, 7, and 14, with 12 rats per sacrifice day. The amount of OTM was measured and PDL widths were assessed histopathologically. RANK-RANKL-OPG expression was assesed immunohistochemically. No statistically significant difference was found between the experimental and control sides regarding OTM and PDL width measurements and RANK-RANKL expressions. OPG expression levels were significantly higher on the control sides on day 14 in pressure areas (P < 0.05). Our data indicate that OTM causes similar changes in bone metabolism activity and PDL width in periodontally compromised tissues, compared to healthy controls. These results underscore the clinical relevance of orthodontic treatment as a safe option for patients with a history of periodontitis.
Feyizoglu et al. (Wed,) studied this question.