Purpose: The prevalence of gingival recession in orthodontically treated patients and the relative impact of retainer type on its occurrence remain poorly understood. The objective of this study was to investigate the association between previous orthodontic treatment and retainer type on the long-term prevalence of gingival recession and to evaluate the role of other patient-related factors, such as gender, age, smoking and gingival phenotype.
Materials and Methods: We included subjects both with and without a history of previous orthodontics (at least 5 years post-treatment). The periodontal status assessment and the presence of gingival recession were recorded. A generalised estimating equation (GEE) logistic regression model was used to examine the effect of the mode of retention and tooth type on recession adjusted for age, smoking, gender and gingival phenotype.
Results: A total of 251 individuals (mean age of 32 ± 9.43 years) were included. Ninety-nine (39.4%) had a history of orthodontics with an observation period of 15.7 years. Those undergoing orthodontics followed by fixed retention had the highest prevalence and magnitude of recession; a history of orthodontics was statistically associated with the occurrence of recession (odds ratio: 2.40; 95% CI: 1.52; 3.82; P 0.001). Both age and the presence of a thin gingival phenotype were significant predictors for recession (P 0.001). The adjusted probabilities of recession per tooth indicated that the mandibular central incisors had the highest probability for recession, with either a fixed or removable retainer.
Conclusions: Based on this observational study, the provision of orthodontic treatment followed by removable or fixed retention had a bearing on the occurrence of recession. The aetiology of gingival recession is multifactorial with a thin periodontal phenotype, age and smoking history being risk factors, while mandibular central incisors are particularly susceptible. Keywords: gingival recession, periodontal disease, orthodontic retainers, orthodontics