Overjet, overbite, and anterior crowding relapses in extraction and nonextraction patients, and their correlations Manoela F avaro Francisconi, a Guilherme Janson, b Karina Maria Salvatore Freitas, c Renata Cristina Gobbi de Oliveira, a Ricardo C  esar Gobbi de Oliveira, a Marcos Roberto de Freitas, b and Jos e Fernando Castanha Henriques b Bauru, S~ ao Paulo, and Maring a, Paran a, Brazil Introduction: In this study, we aimed to compare the relapse of maxillary and mandibular anterior crowding, overjet, and overbite 5 years after treatment in subjects with Class I and Class II malocclusions treated with and without extractions, and also to evaluate the correlations among these factors. Methods: The sample comprised 84 subjects with Class I and Class II malocclusions, treated with and without extractions. Group 1 comprised 44 subjects with an initial mean age of 12.96 years treated without extractions. Group 2 included 40 subjects with an initial mean age of 13.01 years treated with 4 premolar extractions. Data were obtained from dental casts at the pretreatment, posttreatment, and long-term posttreatment stages. Intergroup comparisons were performed with t tests. To verify the correlations among the relapse of overjet, overbite, and anterior crowding, the Pearson correlation test was used. Results: Maxillary incisor irregularity and its relapse in the nonextraction group were significantly greater at the long-term posttreatment stage and the long-term posttreatment period, respectively. Long-term postreatment overjet changes were similar in the groups. Overbite and its relapse were significantly greater in the extraction group in the long-term posttreatment stage and period, respectively. There was a positive correlation of the relapse of mandibular incisor crowding with the relapse of overjet and overbite, and also a correlation of overjet and overbite relapses. Conclusions: There was greater maxillary crowding relapse in the nonextraction group and greater overbite relapse in the extraction group. There were significant and positive correlations of overjet and overbite relapses with mandibular anterior crowding relapse and conse- quently between overjet and overbite relapses. (Am J Orthod Dentofacial Orthop 2014;146:67-72) O rthodontic treatment has several goals, and one of the most important is the stability of the achieved corrections. It is a consensus in the literature that some occlusal changes will inevitably occur after ortho- dontic treatment. 1,2 It would be greatly interesting if orthodontists could precisely predict the occlusal changes that occur after treatment. For this reason, the effects of different diagnosis and treatment factors in long-term treatment stability have been extensively stud- ied. 1,3-5 It is well accepted that the stability of tooth alignment is highly variable and unpredictable. 1 Many authors have considered stability of the mandibular inci- sors after orthodontic treatment as an unreachable ideal and suggested long-term retention as the most plausible solution. 1,2,6 Recent research has also shown that overjet is often corrected during treatment; however, a significant post- treatment relapse of this characteristic is often observed. 7,8 Relapse is related to the amount of overjet at the beginning of treatment, the initial inclination of the maxillary incisors, the labial inclination of the maxillary incisors in the postretention period, the lingual inclination of the mandibular incisors in the postretention period, and the increase of the interincisal angle at the end of treatment. 8,9 Several factors are related to overbite relapse, including overjet, movement of the incisors and molars, interincisal angle, anterior face height, pattern of craniofacial growth, initial incisor crowding (the Little a Graduate student, Department of Orthodontics, Bauru Dental School, University of S~ ao Paulo, Bauru, S~ ao Paulo, Brazil. b Professor, Department of Orthodontics, Bauru Dental School, University of S~ ao Paulo, Bauru, S~ ao Paulo, Brazil. c Associate professor, Department of Orthodontics, Ing a Dental School, Maring a, Paran a, Brazil. All authors have completed and submitted the ICMJE Form for Disclosure of Po- tential Conflicts of Interest, and none were reported. Address correspondence to: Manoela F avaro Francisconi, Department of Ortho- dontics, Bauru Dental School, University of S~ ao Paulo, Alameda Oct avio Pinheiro Brisolla 9-75, Bauru, S~ ao Paulo 17012-901, Brazil; e-mail, manuff@usp.br. Submitted, October 2013; revised and accepted, April 2014. 0889-5406/$36.00 Copyright Ó 2014 by the American Association of Orthodontists. http://dx.doi.org/10.1016/j.ajodo.2014.04.012 67 ORIGINAL ARTICLE