The major objective of the proposed research is to test the hypothesis that orthodontic tooth movement and root resorption can be predicted by and will correlate with biochemical and histomorphometric measures of alveolar bone turnover. This will be tested in rats of two developmental stages (prepubertal and adult) with four levels of initial orthodontic force (0, 20, 40, and 60 grams). This research design will facilitate the measurement of bone turnover parameters in the alveolar bone adjacent to treated teeth under conditions where tooth movement and root resorption should vary considerably. About 2/3 of the population can be categorized as having a treatable malocclusion. Moreover, the demand for orthodontic services has risen steadily in recent decades such that orthodontics now constitutes a major category of dental treatments. Orthodontic tooth movement remains one of the major means by which malocclusions are treated and represents a rate- limiting step in treatment time. Root resorption is cited as one of the major unwanted sequelae to orthodontic tooth movement. There is considerable individual variation in orthodontic tooth movement and root resorption and the degree to which biological parameters contribute to this variation is not well understood. The long-term goal of this work is to identify the significant bone turnover parameters in orthodontic tooth movement and root resorption and to study their impact on individual variation in the clinical context. Using the rat model we will alter one biological (developmental stage) and one biomechanical (force magnitude) parameter, to create significant changes in the rates of tooth movement and root resorption. These will then be followed as a function of time post-appliance activation. Alveolar bone turnover will be monitored biochemically and histomorphometrically. The biochemical parameter of bone formation will be tissue alkaline phosphatase and osteocalcin; for the resorption, they will be acid phosphatase and tartrate-resistant acid phosphatase. Histomorphometric measures of bone turnover will include measurements of several specific histological features characteristic of bone formation and resorption utilizing routine undecalcified histological preparations and tetracycline- generated vital bone stains.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
1R01DE008659-01
Application #
3222472
Study Section
Oral Biology and Medicine Study Section (OBM)
Project Start
1988-12-01
Project End
1991-11-30
Budget Start
1988-12-01
Budget End
1989-11-30
Support Year
1
Fiscal Year
1989
Total Cost
Indirect Cost
Name
University of Florida
Department
Type
Schools of Dentistry/Oral Hygn
DUNS #
073130411
City
Gainesville
State
FL
Country
United States
Zip Code
32611
Konoo, T; Kim, Y J; Gu, G M et al. (2001) Intermittent force in orthodontic tooth movement. J Dent Res 80:457-60
Gu, G; Lemery, S A; King, G J (1999) Effect of appliance reactivation after decay of initial activation on osteoclasts, tooth movement, and root resorption. Angle Orthod 69:515-22
King, G J; Archer, L; Zhou, D (1998) Later orthodontic appliance reactivation stimulates immediate appearance of osteoclasts and linear tooth movement. Am J Orthod Dentofacial Orthop 114:692-7
Hughes, B; King, G J (1998) Effect of orthodontic appliance reactivation during the period of peak expansion in the osteoclast population. Anat Rec 251:80-6
King, G J; Latta, L; Rutenberg, J et al. (1997) Alveolar bone turnover and tooth movement in male rats after removal of orthodontic appliances. Am J Orthod Dentofacial Orthop 111:266-75
Zhou, D; Hughes, B; King, G J (1997) Histomorphometric and biochemical study of osteoclasts at orthodontic compression sites in the rat during indomethacin inhibition. Arch Oral Biol 42:717-26
Svanberg, G K; King, G J; Gibbs, C H (1995) Occlusal considerations in periodontology. Periodontol 2000 9:106-17
King, G J; Latta, L; Rutenberg, J et al. (1995) Alveolar bone turnover in male rats: site- and age-specific changes. Anat Rec 242:321-8
Dolce, C; Anguita, J; Brinkley, L et al. (1994) Effects of sialoadenectomy and exogenous EGF on molar drift and orthodontic tooth movement in rats. Am J Physiol 266:E731-8
Nixon, C E; Saviano, J A; King, G J et al. (1993) Histomorphometric study of dental pulp during orthodontic tooth movement. J Endod 19:13-6

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