What is the primary effect of orthodontic tooth movement on surrounding bone?

• A. Hypertrophy of alveolar bone without remodeling
• B. Alveolar bone remodeling to accommodate tooth movement
• C. Densification without remodeling
• D. Bone resorption distant from tooth

Answer: (B)

Orthodontic tooth movement relies on remodeling of the surrounding alveolar bone to let the tooth shift while preserving bone integrity. When a force is applied, the pressure side of the tooth’s periodontal ligament area is compressed, triggering resorption of bone in that region. At the opposite, tension side, the ligament is stretched and signals bone formation. This coordinated removal and new bone deposition—bone remodeling—allows the tooth to move along its path with the surrounding bone reorganizing to accommodate it.

This differs from ideas like separate bone hypertrophy without remodeling or densification without restructuring, which wouldn’t enable the tooth to migrate. The resorption and new bone formation occur adjacent to the tooth within the alveolar bone, not distant from it, which is essential for guiding the tooth’s movement.