[Vitality loss: influence of orthodontic process].

Vitality loss is an unusual event that can occur before, during or after an orthodontic treatment. It can lead to loss of sensitivity, color change or necrosis of the pulp tissue. Before starting the orthodontic treatment, we have to identify the tooth's risk (injured tooth, included occlusal trauma...). Knowing that, if an endodontic treatment has to be done, it is better to do it before starting orthodontic forces. Lamps do not provide problems except high intensity halogen ones. RPE on children, Le Fort I and mandibular osteotomies, corticotomies, genioplasties are responsible of a transitory ischemia without reaching a pathogen level. Mini-screws or mini-plates may be iatrogenic, if they impact the root. The repair options depend on the delay before removing the miniscrew and the nature of injured tissue.