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Alignment stability in Class II malocclusion treated with 2- and 4-premolar extraction protocols.
Am J Orthod Dentofacial Orthop. 2006 Aug; 130(2):189-95.AJ

Abstract

INTRODUCTION

The purpose of this study was to compare the postretention stability of the correction of mandibular anterior-tooth irregularity in patients with Class II malocclusions whose orthodontic treatments included extraction of 2 or 4 premolars.

METHODS

A total of 66 patients were selected who initially had at least one-half-cusp Class II malocclusions. Nineteen patients (9 male, 10 female) with an initial mean age of 14.04 years were treated with extraction of 2 premolars (group 1); 47 patients (20 male, 27 female) with an initial mean age of 13.03 years were treated with extraction of 4 premolars (group 2). A subgroup of group 2, with a similar amount of initial anterior-tooth irregularity as group 1, was also compared with group 1. Little's irregularity index was used to evaluate anterior tooth irregularity in dental casts obtained from each patient before treatment, after treatment, and 5 years after active treatment. Initial cephalometric variables, initial treatment priority index, pretreatment age, treatment time, and posttreatment time of the groups were compared with t tests. Similarly, Little's irregularity index values at prettreament, posttreatment, and postretention were also compared with the t test. Cephalometric treatment changes within groups were evaluated with dependent t tests.

RESULTS

There were no statistically significant differences in posttretention anterior-tooth irregularity between groups 1 and 2 or the subgroup.

CONCLUSIONS

Treatment of Class II malocclusion with extraction of either 2 maxillary premolars or 4 premolars provides the same mandibular anterior-tooth alignment stability.

Authors+Show Affiliations

Department of Orthodontics, Bauru Dental School, University of São Paulo, São Paulo, Brazil. jansong@travelnet.com.brNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

16905063

Citation

Janson, Guilherme, et al. "Alignment Stability in Class II Malocclusion Treated With 2- and 4-premolar Extraction Protocols." American Journal of Orthodontics and Dentofacial Orthopedics : Official Publication of the American Association of Orthodontists, Its Constituent Societies, and the American Board of Orthodontics, vol. 130, no. 2, 2006, pp. 189-95.
Janson G, Busato MC, Henriques JF, et al. Alignment stability in Class II malocclusion treated with 2- and 4-premolar extraction protocols. Am J Orthod Dentofacial Orthop. 2006;130(2):189-95.
Janson, G., Busato, M. C., Henriques, J. F., de Freitas, M. R., & de Freitas, L. M. (2006). Alignment stability in Class II malocclusion treated with 2- and 4-premolar extraction protocols. American Journal of Orthodontics and Dentofacial Orthopedics : Official Publication of the American Association of Orthodontists, Its Constituent Societies, and the American Board of Orthodontics, 130(2), 189-95.
Janson G, et al. Alignment Stability in Class II Malocclusion Treated With 2- and 4-premolar Extraction Protocols. Am J Orthod Dentofacial Orthop. 2006;130(2):189-95. PubMed PMID: 16905063.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Alignment stability in Class II malocclusion treated with 2- and 4-premolar extraction protocols. AU - Janson,Guilherme, AU - Busato,Mauro Carlos Agner, AU - Henriques,José Fernando Castanha, AU - de Freitas,Marcos Roberto, AU - de Freitas,Lívia Maria Andrade, PY - 2004/09/28/received PY - 2004/11/15/revised PY - 2004/11/22/accepted PY - 2006/8/15/pubmed PY - 2006/8/22/medline PY - 2006/8/15/entrez SP - 189 EP - 95 JF - American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics JO - Am J Orthod Dentofacial Orthop VL - 130 IS - 2 N2 - INTRODUCTION: The purpose of this study was to compare the postretention stability of the correction of mandibular anterior-tooth irregularity in patients with Class II malocclusions whose orthodontic treatments included extraction of 2 or 4 premolars. METHODS: A total of 66 patients were selected who initially had at least one-half-cusp Class II malocclusions. Nineteen patients (9 male, 10 female) with an initial mean age of 14.04 years were treated with extraction of 2 premolars (group 1); 47 patients (20 male, 27 female) with an initial mean age of 13.03 years were treated with extraction of 4 premolars (group 2). A subgroup of group 2, with a similar amount of initial anterior-tooth irregularity as group 1, was also compared with group 1. Little's irregularity index was used to evaluate anterior tooth irregularity in dental casts obtained from each patient before treatment, after treatment, and 5 years after active treatment. Initial cephalometric variables, initial treatment priority index, pretreatment age, treatment time, and posttreatment time of the groups were compared with t tests. Similarly, Little's irregularity index values at prettreament, posttreatment, and postretention were also compared with the t test. Cephalometric treatment changes within groups were evaluated with dependent t tests. RESULTS: There were no statistically significant differences in posttretention anterior-tooth irregularity between groups 1 and 2 or the subgroup. CONCLUSIONS: Treatment of Class II malocclusion with extraction of either 2 maxillary premolars or 4 premolars provides the same mandibular anterior-tooth alignment stability. SN - 1097-6752 UR - https://www.unboundmedicine.com/medline/citation/16905063/Alignment_stability_in_Class_II_malocclusion_treated_with_2__and_4_premolar_extraction_protocols_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0889-5406(06)00541-5 DB - PRIME DP - Unbound Medicine ER -