In orthodontic tooth movement, which cell type predominates on the TENSION side of the periodontal ligament?

During orthodontic tooth movement, the PDL is subjected to different forces on opposite sides of the root: Tension side — the PDL is stretched; osteoblasts are stimulated to deposit new bone, filling in the space created by tooth movement. This is called apposition or bone deposition. Pressure side — the PDL is compressed; osteoclasts resorb the alveolar bone, allowing the tooth to move through the bone. This is called resorption. The mnemonic: Tension = deposition (add bone); Pressure = resorption (remove bone).