A comparative assessment of failures and periodontal health between 2 mandibular lingual retainers in orthodontic patients. A 2-year follow-up, single practice-based randomized trial.

INTRODUCTION: The objective of this study was to compare the survival rates and periodontal health in patients with 3-strand round twisted (RT) vs 8-strand rectangular braided (RB) fixed retainers bonded to all 6 anterior teeth in the mandible. METHODS: A total of 133 patients completing orthodontic treatment (median age, 24.6 years; 25th percentile, 17.2 years; 75th percentile, 32.4 years; minimum, 15.1 years; maximum, 49.8 years) were randomly allocated in a 1:1 ratio to receive either an RT or RB wire retainer. Inclusion criteria were all mandibular permanent incisors and canines present, no active caries, no restorations, no fractures on the mandibular incisors and canines, no periodontal disease. Patients with poor oral hygiene before debonding were excluded from the trial. The primary outcome was any first-time retainer failure. Secondary outcomes were periodontal index, bleeding on probing, plaque index, gingival index, and probing depth. Randomization was accomplished with random permuted blocks of size 4, 6, or 8 with allocation concealed in sequentially numbered, opaque, sealed envelopes. Blinding was not possible in this trial. Patients were evaluated at baseline, 3, 6, 12, 18, and 24 months after placement of the retainer. Retainer survival was assessed using Cox regression. Periodontal parameters were reported at each time point and generalised estimating equations were used to assess the effect of treatment, time, tooth and treatment X time interaction on the indices. RESULTS: Baseline characteristics were similar between groups; in 1 patient, the intervention was discontinued. During 2-year follow-up 37 of 66 (56.1%, RT group) and 32 of 66 (48.5%, RB group) retainers failed at least once (log-rank test, P = 0.55). The adjusted hazard ratio was 0.69 (95% confidence interval, 0.42-1.12; P = 0.13). Neither age nor gender was a predictor of failure. All periodontal parameters (periodontal index, bleeding on probing, plaque index, gingival index, and pocket depth) were comparable between groups and remained relatively stable during follow-up. CONCLUSIONS: The overall risk for first-time failure was high and amounted to 52.3% (56.1% in the RT group and 48.5% in the RB group). There was no difference in terms of survival or periodontal health between the examined retainers.

One-stage (Warsaw) and two-stage (Oslo) repair of unilateral cleft lip and palate: Craniofacial outcomes.

The aim of this study was to compare facial development in subjects with complete unilateral cleft lip and palate (CUCLP) treated with two different surgical protocols. Lateral cephalometric radiographs of 61 patients (42 boys, 19 girls; mean age, 10.9 years; SD, 1) treated consecutively in Warsaw with one-stage repair and 61 age-matched and sex-matched patients treated in Oslo with two-stage surgery were selected to evaluate craniofacial morphology. On each radiograph 13 angular and two ratio variables were measured in order to describe hard and soft tissues of the facial region. The analysis showed that differences between the groups were limited to hard tissues ­ the maxillary prominence in subjects from the Warsaw group was decreased by almost 4° in comparison with the Oslo group (sella-nasion-A-point (SNA) = 75.3° and 79.1°, respectively) and maxillo-mandibular morphology was less favorable in the Warsaw group than the Oslo group (ANB angle = 0.8° and 2.8°, respectively). The soft tissue contour was comparable in both groups. In conclusion, inter-group differences suggest a more favorable outcome in the Oslo group. However, the distinctiveness of facial morphology in background populations (ie, in Poles and Norwegians) could have contributed to the observed results.