Alveolar bone assessment by cone-beam computerized tomography
Ma ZG, Yang C, Fang B, Xia YH, Mao LX, Feng YM. Three-D imaging of dental alveolar bone change after fixed orthodontic treatment in patients with periodontitis. Int J Clin Exp Med 2015;8:2385-91
Although combined periodontal-orthodontic therapy is an ideal treatment option when periodontal inflammation is well controlled, moving periodontally compromised teeth presents many challenges. Evaluation of alveolar bone status is paramount before orthodontic tooth movement. Cone-beam technology now provides a 3-dimensional radiographic method for the evaluation of both alveolar bone height and density. The aim of this study was to quantify bone density and height in periodontally compromised patients and normal patients who had fixed orthodontic treatment. Eighty-one adults from 18 to 39 years of age with Angle Class II malocclusion were selected and divided into 2 groups. Group 1 consisted of 40 patients with chronic periodontitis and inflammation controlled before orthodontic treatment. They received routine periodontal maintenance every 3 months during orthodontic treatment. Group 2 included 41 patients with healthy periodontal tissues. These groups were matched for degree of malocclusion, sex, and age. Cone-beam computed tomography images were taken before and after orthodontic treatment and analyzed for bone density and alveolar bone height. The results showed that although there was no significant bone height loss in either group, there was a significant loss in bone density in both groups. The pretreatment values for alveolar bone density and height were both, on average, smaller in patients with chronic periodontitis. In addition, group 1, with inflammation well controlled, showed a greater decrease in bone density than did group 2. This study indicates that orthodontic therapy may preserve bone height but cannot maintain bone density. The authors concluded that orthodontists should be more concerned about bone density loss in patients undergoing combined orthodontic-periodontal treatment.
Reviewed by Tyler Rathburn
Maxillary fixed retention: survival rate and periodontal health
Dietrich P, Patcas R, Pandis N, Eliades T. Long-term follow-up of maxillary fixed retention: survival rate and periodontal health. Eur J Orthod 2015;37:37-42
The importance of retention to the maintenance of postorthodontic alignment is supported by the work of Little, who reported that only 10% of patients have acceptable mandibular anterior alignment after 20 years. Previous studies have shown that long-term retention of mandibular incisors with a fixed retainer had no negative effects on the teeth and periodontal health, and their main benefit is prevention of relapse without active forces. The objectives of this retrospective study were to assess the long-term stability of maxillary bonded retainers and their effect on gingival health. Forty-one consecutively treated patients (25 female, 16 male) participated in the study. Retainers were fabricated of 0.016 × 0.016-in stainless steel and bonded to the maxillary central and lateral incisors. The variables assessed included the irregularity index for the incisors and canines, previous irregularity index at debond, plaque index, probing depths, bleeding on probing, and incidences of loose retainers, wire fractures, and total retainer loss. The irregularity index findings demonstrated that the incidence of change was low in patients whose retainer was maintained, with only 6 of 41 patients having a change. Periodontal health indicators showed a median value of the gingival index of 1.10, corresponding to mild inflammation, and a median value of the plaque index for all bonded teeth of 1.14. Bleeding on probing of the teeth bonded to the retainer for each participant was 22.3%. Additionally, 46% of the patients had at least 1 periodontal site with a probing depth of more than 3 mm. Twenty-eight of the 41 patients experienced no failure of the maxillary bonded retainer (68.3%). The authors concluded that maxillary bonded fixed retainers seem to cause no significant negative effects on periodontal health, despite a slight increase in plaque accumulation.
Reviewed by Jose Morales Gonzalez