Functional stability analyses of maxillofacial skeleton bearing cleft deformities

Area of Science:

• Craniofacial biology
• Biomechanical engineering
• Dental and Maxillofacial Surgery

Background:

• Congenital craniofacial deformities, particularly orofacial clefts, are associated with bony defects impacting facial structure and stability.
• Maxillary instability and secondary deformities are common in patients with orofacial clefts, but the precise relationship with bony defects remains unclear.
• Understanding the biomechanics of maxillary instability is crucial for improving treatment outcomes in patients with craniofacial deformities.

Purpose of the Study:

• To investigate the detailed relationship between cleft-related bony defects and maxillary instability under occlusal loading using finite element modeling.
• To explore the pattern and extent of maxillary instability associated with different types of orofacial clefts.
• To correlate observed instability patterns with secondary maxillary deformities in patients with craniofacial deformities.

Main Methods:

• Generation of craniofacial models from cone-beam computed tomography (CBCT) data for normal and cleft individuals.
• Application of finite element analysis (FEA) to simulate occlusal loading and assess craniofacial deformation.
• Comparison of biomechanical responses, including asymmetry, arch contraction, and protrusion, across different cleft types (palatal, alveolar, unilateral, bilateral).

Main Results:

• All cleft models exhibited greater asymmetry in deformation during mastication compared to normal models.
• Models with palatal clefts showed increased asymmetry, dental arch contraction, and reduced maxillary protrusion compared to alveolar clefts.
• Unilateral clefts resulted in differential protrusion and elevation of the alveolus, while bilateral clefts presented with severely contracted arches and premaxillary displacement.

Conclusions:

• Cleft type dictates specific patterns of maxillary instability, correlating with observed dentoalveolar morphological features.
• The study elucidates the biomechanical link between bony defects and maxillary instability in orofacial clefts.
• Findings provide a foundation for studying abnormal maxillary and dental arch growth in patients with craniofacial deformities.