Mandibular ramus remodeling after vertical osteotomy: a three-dimensional quantitative and qualitative assessment...

Area of Science:

• Oral and Maxillofacial Surgery
• 3D Imaging and Modeling
• Skeletal Remodeling

Background:

• Intraoral vertical ramus osteotomy (IVRO) is a key surgical technique for correcting mandibular prognathism and asymmetry.
• Understanding the long-term three-dimensional (3D) bone remodeling patterns of the mandibular ramus post-IVRO is crucial for surgical success.

Purpose of the Study:

• To quantitatively and qualitatively analyze the 3D remodeling patterns of the mandibular ramus one year after IVRO.
• To investigate the relationship between segmental overlapping patterns and bone remodeling (resorption and apposition).

Main Methods:

• Reconstruction of 3D mandibular models from CT data of 108 hemi-mandibles from 54 patients.
• Direct segmental-isolated marrow superimposition to compare immediate postoperative and one-year postoperative segments.
• Categorization of patients into groups (A, B, C, D) based on segmental overlapping patterns.

Main Results:

• Significant regional bone resorption and apposition were observed, leading to a remodeled ramus.
• Resorption-dominant remodeling occurred in more overlapped segments (Groups A and B) compared to less overlapped ones (Groups C and D).
• Bone resorption correlated negatively with protrusion delta, while apposition correlated positively with maximum mouth opening.

Conclusions:

• The study demonstrates dynamic remodeling of the ramus after IVRO, influenced by segmental overlap, aiming to create a smooth skeletal contour.
• The novel superimposition method effectively reveals detailed bone remodeling patterns following IVRO.