Three-dimensional assessment of soft tissue changes associated with bone-anchored maxillary protraction protocols

Area of Science:

• Orthodontics and Dentofacial Orthopedics
• Craniofacial Biology
• Biomaterials in Orthodontics

Background:

• Class III malocclusion often involves maxillary deficiency in growing individuals.
• Maxillary protraction is a key treatment strategy for these cases.
• Bone anchorage offers enhanced stability and control for orthodontic movement.

Purpose of the Study:

• To evaluate 3D soft tissue changes in growing Class III patients with maxillary deficiency.
• To compare two bone-anchored maxillary protraction protocols against an untreated control group.
• To assess the efficacy of different miniplate placements for maxillary advancement.

Main Methods:

• Study included growing skeletal Class III patients (10-14 years).
• Group 1: Skeletally anchored facemasks with miniplates at zygomatic buttress.
• Group 2: Class III elastics from infrazygomatic to symphyseal miniplates; Group 3: Untreated controls.
• 3D stereophotogrammetry and lateral cephalometry were used for analysis.

Main Results:

• Significant forward maxillary advancement (4.87mm in Group 1, 5.81mm in Group 2) compared to controls.
• 3D soft tissue analysis revealed significant positive sagittal displacement in upper lips, cheeks, and midface for both treatment groups.
• Lower lip and chin showed significant negative sagittal changes, indicating growth restraint, more pronounced in Group 1.

Conclusions:

• Both bone-anchored maxillary protraction protocols effectively improved the concave soft tissue profile in Class III patients.
• The findings support the use of skeletal anchorage for predictable maxillary advancement.
• Differential effects on lower facial soft tissues were noted between the two protocols.