Effects of unilateral premolar extraction treatment on the dental arch forms of Class II subdivision malocclusions

Abstract Objectives: To determine the amount of variation in overjet and overbite that may result from changes in upper and lower incisor angulations following upper first premolar extraction treatment in Class II malocclusions. Materials and Methods: Typodonts were set up to simulate a skeletal Class II occlusion treated with upper first premolar extractions. The upper incisor angulation was altered through a range from 100° to 120° to the palatal plane by 2° increments. The overjet and overbite were measured with every 2° of upper incisor angulation change. A regression analysis was performed on the experimental data, and the regression coefficients, slope, and intercept were estimated. Results: Excessive proclination of the lower incisors will result in an abnormal overjet and overbite relationship for any magnitude of upper incisor angulation. A normal lower incisor angulation facilitates the attainment of an optimal occlusion. Excessive palatal root torque of the upper incisors will result in an increase in overjet and a consequent decrease in overbite. If the upper incisors are excessively retroclined, an edge-to-edge incisor relationship will result. Conclusion: Class II camouflage treatment with upper first premolar extractions requires correctly angulated incisors to achieve optimal buccal segment interdigitation and incisor relationship. Labial root torque and interproximal reduction of the lower anterior teeth should be considered when the lower incisors are excessively proclined.

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Extraction or non-extraction treatment for Class II division 2 malocclusion?

Evidence-Based Dentistry ◽

10.1038/sj.ebd.6401329 ◽

2018 ◽

Vol 19 (3) ◽

pp. 88-89

Author(s):

Benjamin J Goldstein ◽

Analia Veitz-Keenan

Keyword(s):

Class Ii ◽

Division 2 ◽

Extraction Treatment

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Recovery of anterior torque loss and correction of deep bite occurred during orthodontic treatment with premolar extraction in Class II patients

AJO-DO Clinical Companion ◽

10.1016/j.xaor.2021.01.007 ◽

2021 ◽

Author(s):

Ki-Ho Park ◽

Young-Guk Park ◽

Jae Hyun Park

Keyword(s):

Orthodontic Treatment ◽

Class Ii ◽

Deep Bite ◽

Premolar Extraction ◽

Torque Loss

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Mandibular growth direction with conventional class II non extraction treatment

American Journal of Orthodontics and Dentofacial Orthopedics ◽

10.1016/s0889-5406(08)80047-9 ◽

1991 ◽

Vol 100 (3) ◽

pp. 295

Keyword(s):

Class Ii ◽

Growth Direction ◽

Mandibular Growth ◽

Extraction Treatment

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Influence of unilateral maxillary first molar extraction treatment on second and third molar inclination in Class II subdivision patients

The Angle Orthodontist ◽

10.2319/100414-710.1 ◽

2015 ◽

Vol 86 (1) ◽

pp. 94-100 ◽

Cited By ~ 3

Author(s):

Christos Livas ◽

Nikolaos Pandis ◽

Johan Willem Booij ◽

Demetrios J. Halazonetis ◽

Christos Katsaros ◽

...

Keyword(s):

Private Practice ◽

Orthodontic Treatment ◽

Statistical Significance ◽

Third Molar ◽

Class Ii ◽

Second Molar ◽

Inclination Angles ◽

And Gender ◽

Extraction Treatment ◽

Over Time

ABSTRACT Objective: To assess the maxillary second molar (M2) and third molar (M3) inclination following orthodontic treatment of Class II subdivision malocclusion with unilateral maxillary first molar (M1) extraction. Materials and Methods: Panoramic radiographs of 21 Class II subdivision adolescents (eight boys, 13 girls; mean age, 12.8 years; standard deviation, 1.7 years) before treatment, after treatment with extraction of one maxillary first molar and Begg appliances and after at least 1.8 years in retention were retrospectively collected from a private practice. M2 and M3 inclination angles (M2/ITP, M2/IOP, M3/ITP, M3/IOP), constructed by intertuberosity (ITP) and interorbital planes (IOP), were calculated for the extracted and nonextracted segments. Random effects regression analysis was performed to evaluate the effect on the molar angulation of extraction, time, and gender after adjusting for baseline measurements. Results: Time and extraction status were significant predictors for M2 angulation. M2/ITP and M2/IOP decreased by 4.04 (95% confidence interval [CI]: −6.93, 1.16; P = .001) and 3.67 (95% CI: −6.76, −0.58; P = .020) in the extraction group compared to the nonextraction group after adjusting for time and gender. The adjusted analysis showed that extraction was the only predictor for M3 angulation that reached statistical significance. M3 mesial inclination increased by 7.38° (95% CI: −11.2, −3.54; P < .001) and 7.33° (95% CI: −11.48, −3.19; P = .001). Conclusions: M2 and M3 uprighting significantly improved in the extraction side after orthodontic treatment with unilateral maxillary M1 extraction. There was a significant increase in mesial tipping of maxillary second molar crowns over time.

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