Evaluation of the effectiveness of piezocision-assisted flapless corticotomy in the retraction of four upper incisors: A randomized controlled clinical trial.

BACKGROUND: Comprehensive orthodontic treatment may last for 20-24 months. Reducing the treatment time has become a common demand from both patients and orthodontists. Minimally invasive piezocision is one of the suggested approaches to accelerate the orthodontic tooth movement. OBJECTIVES: The aim of this randomized controlled clinical trial was to assess the effectiveness of the flapless piezocision procedure in accelerating the retraction of upper incisors. MATERIAL AND METHODS: A single-blinded, parallel-group randomized controlled clinical trial was conducted at the Department of Orthodontics at the University of Damascus Dental School, Syria. The study involved 42 patients (11 males, 31 females) at the age of 16-31 years (mean age: 19.15 years). The patients had class II division I malocclusion and were treated with fixed appliances using the two-step retraction technique. With an allocation ratio of 1:1, the participants were randomly assigned to either the experimental group (n = 21) or the control group (n = 21) using a computer-generated list of random numbers. Allocation was concealed due to the use of sequentially numbered, opaque, sealed envelopes. The primary outcomes were the rate of incisor retraction (RIR) and the time required for retraction. The outcome assessor was blinded. RESULTS: The data analysis included 20 patients in each group. The rate of incisor retraction significantly increased in the experimental group by 53%, with a significant shortening of the retraction time in the experimental group by 27% (p < 0.001). The rate of anchorage loss was significantly lesser in the experimental group (p < 0.001). Regarding the cephalometric assessment, incisor tipping was significantly greater in the control group than in the experimental group. Skeletal measurements showed insignificant changes following retraction between the 2 groups. CONCLUSIONS: The piezocision procedure was found to be effective in accelerating the retraction of 4 upper incisors, reducing the retraction time, preserving anchorage and enhancing root torque control during retraction.

The Effect of Using a Modified Dentoalveolar Distractor on Canine Angulation following Rapid Canine Retraction: A Split-mouth Design Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: New studies have been published and aimed to retract canines by means of distraction osteogenesis to reduce treatment time. Although a great care has been given to achieve a bodily movement of the canines, a significant amount of tipping of the canines has been observed. This trial aimed to assess the effect of applying a modified distractor on canine angulation. MATERIALS AND METHODS: The sample of the study consisted of 14 canines in seven patients (16-25 years). After the osteotomy procedure, two distractors were applied (one distractor on each side). After 5 days of a latency period, the two distractors were activated at a rate of 1 mm/day. RESULTS: There was a significant difference between the two distractors regarding the time required to retract the canines (p = 0.008) and the observed change in canine angulation following retraction (p = 0.028). The change in the overjet and the mandibular plane angle was statistically insignificant. Eight out of 14 distracted canines reacted positively to the pulp vitality tester after 3 months of completion of distraction. There was no clinical sign of discoloration or pulpal pain in any canine. CONCLUSION: Within the limits of this study, the modified distractor caused a bodily movement of the canine with a minimal tipping. Further research is required on a long-term basis on a larger group of patients to gain more insight on the observed changes.