Root resorption during orthodontic tooth movement: a literature review

ABSTRACT

External root resorption [ERR] of permanent teeth is an unpredictable consequence of orthodontic treatment, usually diagnosed on periapical radiographs. The etiological and biochemical mechanisms are still unclear. Theories include excessive force that leads to the development of an avascular area referred to as hyalinized, resulting, through a cascade of cellular events, in increased cementoclast-osteoclast activity. Yet, risk .factors are incriminated that may be classified in two major categories constitutional factors [gender, chronologic and dental ages, genetics, individual susceptibility, systemic factors, tooth structure, alveoloar hone density, specific tooth vulnerability to root resorption]; physiologic and environmental factors [nutrition, habits, occlusal trauma, endodontic treatment, trauma prior to orthodontic treatment, mechanical pressure such as types of orthodontic movement, appliances, and forces, duration of orthodontic treatment, repeated orthodontic treatment]. When resorption is detected, treatment objectives should be modified to maintain appropriate crown-to-root ratio and periodontal health, while light forces are used and root length monitored