External apical root resorption (EARR) is a common complication of orthodontic treatment. Nevertheless, effective preventive strategies have not yet been established. Here, we demonstrated that administration of green tea catechin (epigallocatechin gallate: EGCG), at concentrations equivalent to habitual human daily intake when adjusted for rat body weight, prevented root resorption while preserving tooth movement in rats. An L-loop orthodontic appliance was used to induce vertical intrusive tooth movement for the maxillary first molar; EGCG was administered at doses of 1 and 2 mg every other day for 14 days (without EGCG for control). Tooth movement and root resorption were assessed using micro-computed tomography (µCT) as well as histological staining hematoxylin and eosin (H-E) and tartrate-resistant acid phosphatase (TRAP). Despite no impairment in tooth movement in all groups, root resorption was significantly suppressed in the EGCG-administered groups. These findings suggest that habitual consumption of tea containing EGCG at daily concentrations may provide safe and effective strategies for orthodontic treatment.
TATSUMI et al. (Thu,) studied this question.