Self-ligating Vs conventional twin brackets during En-masse space closure with frictionless mechanics

MATERIALS AND METHODS: Twenty consecutive patients who met the selection criteria were included in the study in the Dept. of Orthodontics, Ragas Dental College & Hospital, Chennai. The inclusion criteria for all twenty patients were as follows. 1. Adolescent / younger adult in permanent dentition of either gender 2. All first bicuspid extraction 3. Class 1 molar relation 4. Group A anchorage 5. First and second molars to be banded or bonded in upper and lower jaw Previous history of orthodontic treatment, any missing tooth other than third molar, root canal treated tooth or any temporomandibular dysfunction were excluded from the study. Twenty patients were randomly divided into two groups of ten each: Group A and Group B. Group A patients was bonded with conventional pre-adjusted edgewise, Roth 0.022 slot brackets (Ovation;Dentsply,GAC) Fig(2) and Group B patients was bonded with self-ligating pre-adjusted edgewise, Roth 0.022 slot brackets (In-Ovation-R; Dentsply, GAC) Fig(2). which were positioned with Boon’s gauge, in both upper and lower arch. The first and second molars were banded with Roth prescription with weldable buccal tube and lingual sheath was used in the first molars for transpalatal arch Leveling and aligning was done with 0.016-inch NiTi (Lancer orthodontics) in the upper arch and 0.014-inch or 0.016-inch NiTi in the lower arch depending on the crowding followed by 0.018inch SS (A.J. Wilcock special plus Australia.) and 19×25 NiTi (Lancer orthodontics) wire in both upper and lower arch. After alignment, preformed 19×25-inch SS double key-hole loop archwire (Truforce stainless steel, Ortho Technology USA) was placed passively for 4 weeks. Then 100 gable bend with reverse curve was placed bilaterally mesial to the second loop and the loop was activated by 1mm to produce a force of 150g/side and tied with Suzuki tie from the second molar hook to the second loop of the wire Fig (5). Reactivation was done once in four weeks after canine attains its mesial tip. Lateral cephalograms and models were taken at the beginning of retraction (T1) and at the end of retraction (T2) Fig (6, 7, 8, 9). To differentiate the right and left sides on the lateral cephalogram, a jig was fabricated using 19×25-inch SS wire in ”Z” shape for the right side and “L” shape for the left side, ligated to the canine bracket and first molar buccal tube in both arches Fig(1). All lateral cephalograms were traced by the same investigator. RESULTS: This study comprised of 20 patients divided into two groups, Group A and Group B, of 10 patients each. The mean age of the patient were16 years ±3.2 years in both the groups. The results are discussed under the following headings: Molar Anchorage Loss in Group A between right and left sides: Table 1a Molar anchor loss within group A is tabulated in Table 1a. Results showed there was no statistically significant difference in molar anchor loss between right and left side in both the arches. Molar Anchorage Loss in Group B between right and left sides: Table 1a Molar anchor loss within group B is tabulated in Table 1a. Results showed there was no statistically significant difference in molar anchor loss between right and left side in both the arches. CONCLUSION: The following conclusions can be made from the present study. 1. There was no difference in the quantum of molar anchorage loss between conventional brackets and self-ligating brackets in both the arches. 2. No difference in the quantum of anterior retraction between conventional brackets and self-ligating brackets in both the arches was observed. 3. Conventional and self-ligating brackets were no different in the amount of anterior torque expression and molar tipping in both the arches. 4. However there was perceivable difference in total retraction time with self-ligating brackets being faster compared to the conventional brackets. Therefore, both the bracket systems are equally efficient during en-masse retraction with loop mechanics