Alignment efficiency of Damon3 self-ligating and conventional orthodontic bracket systems: A randomized clinical trial

Introduction: The aim of this study was to compare the efficiency of mandibular tooth alignment and the clinical effectiveness of a self-ligating and a conventional preadjusted edgewise orthodontic bracket system. Methods: A multicenter randomized clinical trial was conducted in 2 orthodontic clinics. Sixty-two subjects (32 male, 30 female; mean age, 16.27 years) with mandibular incisor irregularities of 5 to 12 mm and a prescribed extraction pattern including the mandibular first premolars were randomly allocated to treatment with Damon3 self-ligating (Ormco, Glendora, Calif) or Synthesis (Ormco) conventionally ligated brackets. Fully ligated 0.014-in nickel-titanium archwires were used first in both groups, followed by a sequence of 0.014 x 0.025-in and 0.018 x 0.025-in nickel-titanium, and 0.019 x 0.025-in stainless steel. Study casts were taken at the start of treatment (T1), the first archwire change (T2), and the placement of the final 0.019 x 0.025-in archwire (T3). Cephalometric lateral skull and long-cone periapical radiographs of the mandibular incisors were taken at T1 and T3. Results: No significant difference was noted (P >0.05) in initial rate of alignment for either bracket system. Initial irregularity influenced subsequent rate of movement, but sex, age, and appliance type were statistically insignificant. Alignment was associated with an increase in intercanine width, a reduction in arch length, and proclination of the mandibular incisors for both appliances, but the differences were not significant. Incisor root resorption was not clinically significant and did not differ between systems. Conclusions: Damon3 self-ligating brackets are no more efficient than conventional ligated preadjusted brackets during tooth alignment. (Am J Orthod Dentofacial Orthop 2008;134:470.e1-470.e8)