Incidence of canal calcification in the orthodontic patient.

References in the endodontic literature specifically warn that orthodontic treatment may initiate the formation of secondary dentin deposition within a tooth to the extent of obstructing the entire root canal. Comparison of forty-six orthodontically treated patients with a control group of age- and sex-matched patients who had not undergone orthodontic treatment revealed two orthodontically treated patients with a total of three teeth that showed evidence of canal calcification. Although this incidence is not statistically significant, the clinical significance of canal calcification in the orthodontic population is discussed.