UCSF

Periodontium is defined as the tissues that surround and provide support to the natural dentition. Throughout orthodontic tooth movement, the forces on the teeth cause periodontal soft tissue and hard tissue remodeling. Degree of orthodontic rotation and proclination, keratinized tissue width (KTW), mid-facial recession, tissue phenotype and interdental papilla dimension are the main parameters of interest in this study as they affect the esthetic outcomes of not only orthodontic treatment, but also, other restorative dental procedures. Thus, the purpose of the study is to analyze the effect of orthodontic rotation and proclination produced by low levels of orthodontic force on the periodontium in the esthetic zone (canine to canine) during the first six months of treatment. This study is a prospective cohort study. Patients of the University of California, San Francisco (UCSF) postgraduate orthodontic clinic receiving orthodontic treatment with full fixed appliances or removable clear aligners are included. The variables measured for this study are the degrees of rotation of each tooth before and after orthodontic alignment, KTW, mid-facial recession, tissue phenotype and interdental papilla dimension. During the first six months of treatment, this study found: 1) An increase in orthodontic rotation is significantly correlated with a decrease in the alveolar housing width at the level of S1, or 3 mm apical to the cementum enamel junction (CEJ). 2) Orthodontic rotation has minimal impact on soft tissue changes in the anterior dentition. 3) Changes in degree of upper incisor inclination are correlated with an increase in papilla height and width, a decrease in midfacial recession, and a decrease in alveolar housing at the level of S1.