Korean J Orthod.  2006 Aug;36(4):242-250.

Expression of UNC-50 DNA in periodontal tissue of rats after application of intermittent orthodontic force

• Park MK
• Park JC
• Lim SH
• Kim KW

Abstract

OBJECTIVE
Periodontal ligament fibroblasts have an ectomesenchymal origin and are thought to play a crucial role for not only homeostasis of periodontal tissues but also bone remodeling, wound healing and regeneration of tissues. Recently, it has been reported that UNC-50 is not expressed in gingival fibroblasts but in PDL fibroblasts. The purpose of this study was to examine the expression of UNC-50 and osteocalcin in the periodontium after application of intermittent force.
METHODS
Twelve rats had 40 grams of mesially-directed force applied at the upper molar for 1 hour/day. Four rats were sacrificed at 1, 3 and 5 days. Immunohistochemical localization of UNC-50 and osteocalcin antibody was carried out. The results showed apposition of new cellular cementum and a slight increase in periodontal space at the tension side.
RESULTS
Strong UNC-50 expression was observed in the differentiating cementoblasts close to PDL fibroblasts in the tension side whereas it was barely expressed at the compression side. Expression was strong at day 3, and decreased at day 5. Osteocalcin immunoreactivity expression was strong in differentiating cementoblasts at the tension side.
CONCLUSION
It can be suggested that UNC-50 is related to the differentiation of cementoblasts, and may be responsible for the molecular event in PDL cells under mechanical stress.

Keyword

Mechanical stress; UNC-50; Cementoblast

MeSH Terms

Animals
Bone Remodeling
Dental Cementum
DNA*
Fibroblasts
Homeostasis
Molar
Osteocalcin
Periodontal Ligament
Periodontium
Rats*
Regeneration
Stress, Mechanical
Wound Healing
DNA
Osteocalcin