Conventional and self-ligating lingual orthodontic treatment outcomes in Class I nonextraction patients: A comparative study with the American Board of Orthodontics Objective Grading System

This study aimed to assess and compare the duration and outcomes of orthodontic treatment with conventional and self-ligating lingual fixed appliances with the American Board of Orthodontics (ABO) Objective Grading System. Thirty consecutive patients with a complete dentition and Angle Class I malocclusion treated with a conventional lingual bracket system (STb; Ormco, Glendora, Calif) or self-ligating lingual bracket system (GC Experience-L; GC Orthodontics, Breckerfeld, Germany) were included. The occlusal outcome was assessed with the ABO instrument. The treatment duration and ABO scores of the 2 groups were recorded. Statistical analyses were evaluated using independent-sample t tests. The conventional group had a mean treatment time of 2.10 ± 0.69 years, and the self-ligating group had a treatment duration of 1.68 ± 0.48 years (P >0.05). The mean posttreatment ABO scores in the conventional group were 20.23 ± 5.13, and the mean posttreatment ABO scores in the self-ligating group were 21.00 ± 5.66. No difference was found between the groups regarding the criteria of ABO (P >0.05). The highest scores were given in the assessment of buccolingual inclinations in both conventional and self-ligating lingual bracket groups. The design of the lingual appliances used in this study did not influence the treatment duration and the total ABO scores in treating patients with a Class I relationship in this sample. Both types of lingual brackets were especially deficient in correcting buccolingual inclinations. The strengths were their ability to close spaces and correct anterior rotations and overjet regardless of the bracket types. •Treatment results were compared between self-ligating and conventional lingual brackets.•The choice of lingual bracket type affected the total Objective Grading System scores.•Self-ligating lingual brackets did not reduce the duration of treatment.•Buccolingual inclination appears to complicate lingual orthodontic treatment the most.•Lingual appliances presented difficulties in ensuring the root parallelism of the premolars.