Nasolabial morphological changes following anterior vs. subapical maxillary segmental osteotomy: a comparative study

Area of Science:

• Orthodontics and Maxillofacial Surgery
• 3D Cephalometric Analysis
• Skeletal and Soft Tissue Morphology

Background:

• Maxillary protrusion presents challenges in achieving optimal facial aesthetics and function.
• Surgical correction often involves anterior maxillary osteotomies to reposition the maxilla.
• Comparing different osteotomy techniques is crucial for refining treatment outcomes.

Purpose of the Study:

• To compare the effects of anterior maxillary segmental osteotomy (AMSO) and subapical anterior maxillary segmental osteotomy (SAMSO) on nasolabial morphology.
• To evaluate hard and soft tissue changes following these surgical procedures using 3D cephalometry.
• To analyze correlations between skeletal movements and soft tissue alterations.

Main Methods:

• Retrospective analysis of 45 patients with maxillary protrusion treated with AMSO or SAMSO.
• Pre- and post-operative cone-beam computed tomography (CBCT) scans obtained ≥1 year after surgery.
• Measurement of 11 distances and 4 angles on lateral views, and 4 distances and 1 angle on frontal views to assess hard and soft tissue changes.

Main Results:

• Both AMSO and SAMSO effectively achieved posterior displacement of the anterior maxilla and reduced maxillary prognathism.
• AMSO resulted in greater vertical impaction of the anterior maxilla and more significant upper lip protrusion retraction compared to SAMSO.
• AMSO led to increased alar base width, while SAMSO showed significant increases in nasal height and nasal tip angle.

Conclusions:

• Both AMSO and SAMSO are effective in correcting maxillary protrusion, improving lip protrusion, and enhancing facial profiles.
• AMSO demonstrates a more pronounced impact on both sagittal and frontal nasolabial soft tissue dimensions.
• SAMSO primarily influences sagittal soft tissue changes with less effect on frontal nasal morphology.