Does Lip Change Following Premolar Extraction Differ in Patients with High and Normal Vertical Growth Patterns?

Area of Science:

• Orthodontics
• Cephalometric analysis
• Soft tissue changes

Background:

• Understanding soft tissue changes is crucial in orthodontic treatment planning.
• Vertical growth patterns significantly influence facial aesthetics and treatment outcomes.

Purpose of the Study:

• To evaluate the relationship between incisor retraction and lip repositioning in high vertical (HVP) and normal vertical (NVP) growth patterns.
• To assess the influence of vertical growth patterns on soft tissue changes after extraction treatments.

Main Methods:

• Analysis of pre- and post-treatment lateral cephalograms of 79 patients who underwent premolar extractions.
• Classification of patients into HVP (FMA >30°) and NVP (22° < FMA ≤30°) groups.
• Measurement of horizontal and vertical lip changes, labiomental fold, and lip strain, assessing correlations with incisor movements.

Main Results:

• Greater upper lip retraction observed in the HVP group (2.86 mm) compared to the NVP group (1.97 mm).
• Significant decrease in upper lip height and strain in both groups, more pronounced in HVP for strain.
• Strong correlation between incisor retraction and upper lip changes in both groups; also with lower lip and labiomental fold in NVP group.

Conclusions:

• Soft tissue response to incisor retraction is influenced by vertical growth patterns.
• Greater upper lip retraction in HVP patients necessitates consideration of vertical growth patterns for optimal soft tissue outcomes.