During which stage do PDL fibroblasts primarily facilitate axial tooth movement?

• A. Preeruptive stage
• B. Post-eruptive stage
• C. Eruptive stage
• D. Post-gingival stage

Answer: (C)

Axial eruption is driven by the periodontal ligament fibroblasts remodeling the ligament and coordinating bone changes as the tooth moves along its long axis into the functional position. In the eruptive stage, these cells generate and transmit forces within the PDL and regulate bone resorption in front of the moving tooth and bone formation behind it, creating a coordinated push that allows the tooth to progress toward the occlusal plane. Earlier, in the preeruptive stage, the tooth resides within the jaw with limited PDL function for eruption, so axial movement isn’t driven by PDL fibroblasts in the same way. After eruption, during the post-eruptive period, the tooth is already in place and any further axial adjustments relate more to growth and wear than to eruption itself, so PDL fibroblasts aren’t the primary drivers of axial movement then. The post-gingival stage isn’t a standard phase for eruption-driven axial movement.