Biomechanics of Root Resorption: PDL Necrosis, Occlusal Trauma and Root Flexure

Despite a relatively low force to deflection rate for initial archwires, the highest risk for external apical root resorption (EAAR) is during the first 6 months of treatment (initial alignment). Relative to biomechanics, the major risk factors for EARR are genetic predisposition, occlusal trauma, root flexure, PDL inflammation and cell necrosis.

Learning Objectives:

• Recognize the role of PDL necrosis in the biomechanics of applied loads.
• Analyze the relationship between occlusal trauma and root flexure.
• Compare the interactive biomechanics of PDL necrosis, occlusal trauma, and root flexure on the expression of root resorption.