Radiographs of the mandible can be utilized to characterize loss of bone density elsewhere. In addition this investigation indicated that optical densitometry is an inexpensive and low risk method for studying bone density.

Background and Aim: Captopril is an oral angiotensin-converting-enzyme (ACE) inhibitor extensively used in the treatment of hypertension and heart failure. ACE has been suggested to function in bone cells and might therefore impact orthodontic tooth movement (OTM). Considering the controversy surrounding the effects of ACE and its inhibitors on osseous tissues, we aimed to evaluate the effect of captopril on OTM for the first time in a rat model. Materials and Methods: Orthodontic appliances were fixed between the left first molars and incisors of 30 rats divided into three groups (n=10) receiving captopril, saline or no treatment. Following sacrifice on day 21, the amount of tooth movement was measured as the distance created between the first and second molars. Bone density was assessed by lateral cephalograms on days 1 and 21 and osteoclast number, root resorption and periodontal ligament (PDL) width were analyzed histologically. One-way ANOVA followed by post-hoc test were used for statistical analysis (P<0.05) Results: OTM significantly increased in the captopril group compared to the saline and no-treatment groups (P<0.05). Bone density significantly decreased in the mandible of the captopril group from day 1 to 21 (P<0.05). No significant differences were found in the histological variables except for the significant increase in PDL width at the mesioapical aspect in the captopril group. Conclusion: The present study showed that captopril administration could lead to increased OTM and decreased bone density in rats. Further studies are suggested to clarify its exact role at the cellular and molecular levels.

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Background: This study aimed to evaluate the cone-beam computed tomography (CBCT) technique considering its reliability to diagnose resorption due to maxillary impacted canine. Methods: In this cross-sectional study, 68 CBCT images were observed by two oral and maxillofacial radiologists. The position of the impacted maxillary canine was assessed, and the severity of root resorption in adjacent teeth was determined in two rounds by viewing. Finally, statistical analyses were performed according to the percentage of agreement, intra-class correlation coefficient, and kappa. The data sheets were filled out by two radiologists who observed the CBCT images in two separate weeks and recorded their opinions about the position of the crown and root of the impacted maxillary canine. Further, four adjacent teeth were examined for root resorption. Results: In most cases, no root resorption was observed in the lateral, central, and first premolars; however, the reported percentage of root resorption in the lateral premolar was higher than that of the others, and no root resorption was reported in the second premolars. Agreement on crown and root position was reported to be above 90% in all observations. In addition, the percentage of agreement was 98.5%, 95.6%, 98.5%, and 100% for root resorption, central incisor, lateral incisor, the first premolar, and the second premolar, respectively. Maxillary impacted canines were examined considering root resorption in adjacent teeth using CBCT, and its interpretation was reliable. Conclusions: Utilization of CBCT provides a worthy data about the impacted maxillary canine localization and effects on adjacent teeth, for more explanation and treatment of these cases.