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Long-term profile changes associated with successfully treated extraction and nonextraction Class II Division 1
E C Zierhut1, D R Joondeph, J Artun
1Department of Orthodontics, University of Washington, Seattle, USA. ezierhut@aol.com
The Angle Orthodontist
|August 5, 2000
Summary
Orthodontic treatment for Class II, division 1 malocclusions, whether with or without first premolar extractions, resulted in similar soft tissue facial profiles. Maturational changes, not extractions, influenced profile flattening over time.
Area of Science:
- Orthodontics and Dentofacial Orthopedics
- Cephalometric Analysis
- Facial Profile Esthetics
Background:
- Class II, division 1 malocclusion is a common dental anomaly affecting facial aesthetics.
- Treatment decisions, including premolar extractions, can influence long-term soft tissue profiles.
- Understanding the impact of extraction versus nonextraction therapy on facial profiles is crucial for treatment planning.
Purpose of the Study:
- To compare the post-treatment and long-term soft tissue facial profiles of Class II, division 1 malocclusions treated with either first premolar extractions or nonextraction therapy.
- To test the hypothesis that well-executed extraction decisions lead to comparable soft tissue profiles with nonextraction cases.
Main Methods:
- A sample of 63 Caucasian adolescents with Class II, division 1 malocclusions was analyzed.
- Patients were divided into two groups: 23 treated with 4 first premolar extractions and 40 treated nonextraction.
- Lateral cephalometric radiographs were evaluated at pretreatment, post-treatment, and long-term post-retention stages.
Main Results:
- No significant differences were found in soft tissue facial profiles between the extraction and nonextraction groups post-treatment and long-term.
- Progressive flattening of the facial profile was observed in both groups, attributed to natural maturational changes (mandibular growth, nasal development).
- Long-term lip positions were more retrusive than some established ideals but comparable to untreated adults.
Conclusions:
- Extraction decisions in Class II, division 1 malocclusion treatment, when successful, do not negatively impact long-term soft tissue facial profiles compared to nonextraction therapy.
- Maturational changes, including mandibular growth and nasal development, are primary drivers of facial profile changes during adolescence and early adulthood.
- Pretreatment lower lip position and thickness, along with the initial maxillomandibular relationship, may predict long-term lip positioning.