Effect of periodontal phenotype characteristics on post-extraction dimensional changes of the alveolar ridge: A prospective case series

Abstract

Aim: This study was primarily aimed at assessing the effect that specific periodontal phenotypical characteristics have on alveolar ridge remodelling after tooth extraction. Materials and Methods: Patients in need of extraction of a non-molar maxillary tooth were enrolled. Baseline phenotypical characteristics (i.e., mid-facial and mid-palatal soft tissue and bone thickness, and supracrestal soft tissue height [STH]) were recorded upon extraction. A set of clinical, digital imaging (linear and volumetric), and patient-reported outcomes were assessed over a 14-week healing period. Results: A total of 78 subjects were screened. Forty-two subjects completed the study. Linear and volumetric bone changes, as well as vertical linear soft tissue and alveolar ridge volume (soft tissue contour) variations, were indicative of a marked dimensional reduction of the alveolar ridge over time. Horizontal facial and palatal soft tissue thickness gain was observed. Thin facial bone (≤1 mm) upon extraction, compared with thick facial bone (>1 mm), was associated with greater linear horizontal (−4.57 ± 2.31 mm vs. –2.17 ± 1.65 mm, p =.003) and vertical mid-facial (−0.95 ± 0.67 mm vs. –4.08 ± 3.52 mm, p < 0.001) and mid-palatal (−2.03 ± 2.08 mm vs. –1.12 ± 0.99 mm, p = 0.027) bone loss, as well as greater total (−34% ± 10% vs. 15% ± 6%, p < 0.001), facial (−51% ± 19% vs. 28% ± 18%, p = 0.040), and palatal bone volume reduction (−26% ± 14% vs. –8% ± 10%, p < 0.001). Aside from alveolar bone thickness, STH was also found to be a predictor of alveolar ridge resorption since this variable was directly correlated with bone volume reduction. Patient-reported discomfort scores progressively decreased over time, and the mean satisfaction upon study completion was 94.5 ± 0.83 out of 100. Conclusions: Alveolar ridge remodelling is a physiological phenomenon that occurs after tooth extraction. Post-extraction alveolar ridge atrophy is more marked on the facio-coronal aspect. These dimensional changes are more pronounced in sites exhibiting a thin facial bone phenotype (Clinicaltrials.gov NCT02668289).