Korean J Orthod.  2004 Dec;34(6):506-513.

Effects on osteoclast in periodontal ligament space by denerveation of inferior alveolar nerve in young and adult rats

• Park KD
• Sung JH
• Bae YC
• Kyung HM

Abstract

Osteoclast action is necessary for alveolar bone remodeling in orthodontic tooth movement. The nervous system has also been reported to be associated with bone remodeling. This study was aimed to investigate the changes of osteoclasts in the periodontal ligament (PDL) space after surgical resection of the inferior alveolar nerve (IAN). Experimental rats were divided into young and adult groups. A surgical resection procedure of the IAN was carried out in the left side of the mandible and a sham operation in the right side of the mandible. The number of osteoclasts on the bundle bone surface and the resorption activity of the osteoclasts were histomorphometrically measured. The changes in distribution of substance P (SP) immunoreactive (IR) nerve fiber were evaluated in the PDL and pulp. SP-IR nerve fiber was depleted in both the PDL and pulp of the IAN resection side in both groups, which confirmed the resection of IAN to be successfully conducted. The number of osteoclasts in the IAN resection side was significantly reduced in both the young and adult groups (p<0.01 and p<0.05), whereas the resorption activity of osteoclasts did not show any significant difference between the IAN resection side and the sham operation side in both groups (p>0.05 and p>0.05). The adult group showed that the number of osteoclasts reduced significantly (p<0.01) and the resorption acitvity didn't change in comparison with the young group (p>0.05). These results suggest that surgical resection of the IAN and aging reduce the population of the recruited osteoclasts within the PDL, but don't affect on the osteoclastic resorption activity.

Keyword

Osteoclast; Inferior alveolar nerve; Denervation; Periodontal ligament space

MeSH Terms

Adult*
Aging
Animals
Bone Remodeling
Denervation
Humans
Mandible
Mandibular Nerve*
Nerve Fibers
Nervous System
Osteoclasts*
Periodontal Ligament*
Rats*
Substance P
Tooth Movement
Substance P