Root resorption associated with orthodontic force in inbred mice: genetic contributions

• Published in: European journal of orthodontics 2006-02, Vol.28 (1), p.13-19
• Main Authors: Al-Qawasmi, Riyad A., Hartsfield, James K., Everett, Eric T., Weaver, Marjorie R., Foroud, Tatiana M., Faust, Deidra M., Roberts, W. Eugene
• Format: Article
• Language: English
• Subjects: Acid Phosphatase - metabolism; Animals; Biomarkers - metabolism; Dental Stress Analysis; Dentistry; Disease Models, Animal; Genetic Predisposition to Disease - genetics; Genotype; Isoenzymes - metabolism; Male; Mice; Mice, Inbred Strains; Random Allocation; Reproducibility of Results; Root Resorption - etiology; Root Resorption - genetics; Tartrate-Resistant Acid Phosphatase; Tooth Movement Techniques - adverse effects
• ISSN: 0141-5387; 1460-2210
• DOI: 10.1093/ejo/cji090

Root resorption (RR) is an unwanted sequela of orthodontic treatment. Despite rigorous investigation, no single factor or group of factors that directly causes RR has been identified. The purpose of this study was to examine the effect of the genotype on susceptibility or resistance to develop RR secondary to orthodontic force. Nine-week-old male mice from eight inbred strains were used and randomly distributed into control (C) or treatment (T) groups as follows: A/J (C = 9,T = 9), C57BL/6J (C = 7,T = 8), C3H/HeJ (C = 8,T = 6), BALB/cJ (C = 8,T = 6), 129P3/J (C = 6,T = 8), DBA/2J (C = 8,T = 9), SJL/J (C = 8,T = 10), and AKR/J (C = 9,T = 8). Each of the treated mice received an orthodontic appliance to tip the maxillary left first molar mesially for 9 days. Histological sections of the tooth were used to determine RR and tartrate resistant acid phosphatase (TRAP) activity. The Wilcoxon ranked-sum non-parametric test was used to evaluate differences between the groups. The results showed that the DBA/2J, BALB/cJ, and 129P3/J inbred mouse strains are highly susceptible to RR, whereas A/J, C57BL/6J and SJL/J mice are much more resistant. The variation in the severity of RR associated with orthodontic force among different inbred strains of mice when age, gender, food, housing, and orthodontic force magnitude/duration are controlled support the hypothesis that susceptibility or resistance to RR associated with orthodontic force is a genetically influenced trait.