title: [Study on biomechanics of incisor movement retracted by Hawley labial wire of removable appliance].
abstract: The authors used the space three point location Approximation method and L-positioner instrument to study the biomechanics of incisor movement retracted by Hawley labial wire of removable appliance. The magnitude, direction and effective point of orthodontic force from the X-ray films and models were measured. More than 2800 data groups were collected. The results showed that; 1) the force of retracted Hawley wire acts on the incisors can be divided into incisal and lingual components, and there was a stable contact point on the incisors; 2) The Hawley wire was constructed by stainless wire of 0.7-0.8 mm in diameter (made in Shanghai Dental Material Factory), retracting it 1mm horizontally may produce 100-150 gm orthodontic force and 3) the direction of tooth movement is not the same direction of orthodontic force, and is affected by resistant force of the periodontal tissue.
authors.affiliation: Nanjing Stomatological Hospital.
authors.forename: F H
authors.initials: FH
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D002648:Child; D003799:Dental Stress Analysis / Q000379:methods; D005260:Female; D006801:Humans; D007180:Incisor; D008297:Male; D009968:Orthodontic Appliances, Removable; D009969:Orthodontic Wires