Fabio Savoldi1, Stefano Bonetti2, Domenico Dalessandri3, Gualtiero Mandelli3, Corrado Paganelli4. 1. Postgraduate Student, Department of Orthodontics, Dental School, University of Brescia , Brescia, Italy . 2. Assistant Professor, Department of Orthodontics, Dental School, University of Brescia , Brescia, Italy . 3. Adjunct Assistant Professor, Department of Orthodontics, Dental School, University of Brescia , Brescia, Italy . 4. Professor and Director, Department of Orthodontics, Dental School, University of Brescia , Brescia, Italy .
Abstract
BACKGROUND: Root resorption shall be taken into consideration during every orthodontic treatment, and it can be effected by the use of different techniques, such as the application of low friction mechanics. However, its routinely assessment on orthopantomography has limitations related to distortions and changes in dental inclination. AIM: The aim of this investigation was to evaluate the severity of apical root resorption of maxillary and mandibular incisors after low-friction orthodontic treatment, using the combination of panoramic and lateral radiographs, and applying a trigonometric correction. SETTINGS AND DESIGN: A hospital based Retrospective study at the orthodontic Department (Dental School, University of Brescia, Spedali Civili di Brescia, Brescia, Italy). MATERIALS AND METHODS: Ninety-three subjects (53 females and 40 males; mean age, 14 years) with mild teeth crowding were treated without extractions by the same operator using a low-friction fixed appliance following an integrated straight wire (ISW) protocol. The pre- and post-treatment tooth lengths of the maxillary and mandibular incisors were measured on panoramic radiographs. A trigonometric factor of correction for the pre-treatment length was calculated based on the difference between the pre and post-treatment incisal inclination on lateral cephalograms. STATISTICAL ANALYSIS: The changes in lengths were investigated using the Student's t-test for paired values (p<0.05). RESULTS: Maxillary central incisors showed no changes (0.3%, 0.6%), maxillary lateral incisors showed a small increase (1.4%, 1.8%) that was attributed to the completion of root development in younger patients, mandibular central and lateral incisors underwent slight resorption (-3.1%, -3.4%). A statistically significant difference was found for the mandibular incisors but not for the maxillary ones. CONCLUSION: In patients with mild crowding and consequent low amount of root movement, a low-friction orthodontic treatment can lead to slight apical root resorption, mainly involving lower incisors. The use of a trigonometric correction in the panoramic radiograph analysis may reduce the limitations of this 2D evaluation.
BACKGROUND: Root resorption shall be taken into consideration during every orthodontic treatment, and it can be effected by the use of different techniques, such as the application of low friction mechanics. However, its routinely assessment on orthopantomography has limitations related to distortions and changes in dental inclination. AIM: The aim of this investigation was to evaluate the severity of apical root resorption of maxillary and mandibular incisors after low-friction orthodontic treatment, using the combination of panoramic and lateral radiographs, and applying a trigonometric correction. SETTINGS AND DESIGN: A hospital based Retrospective study at the orthodontic Department (Dental School, University of Brescia, Spedali Civili di Brescia, Brescia, Italy). MATERIALS AND METHODS: Ninety-three subjects (53 females and 40 males; mean age, 14 years) with mild teeth crowding were treated without extractions by the same operator using a low-friction fixed appliance following an integrated straight wire (ISW) protocol. The pre- and post-treatment tooth lengths of the maxillary and mandibular incisors were measured on panoramic radiographs. A trigonometric factor of correction for the pre-treatment length was calculated based on the difference between the pre and post-treatment incisal inclination on lateral cephalograms. STATISTICAL ANALYSIS: The changes in lengths were investigated using the Student's t-test for paired values (p<0.05). RESULTS: Maxillary central incisors showed no changes (0.3%, 0.6%), maxillary lateral incisors showed a small increase (1.4%, 1.8%) that was attributed to the completion of root development in younger patients, mandibular central and lateral incisors underwent slight resorption (-3.1%, -3.4%). A statistically significant difference was found for the mandibular incisors but not for the maxillary ones. CONCLUSION: In patients with mild crowding and consequent low amount of root movement, a low-friction orthodontic treatment can lead to slight apical root resorption, mainly involving lower incisors. The use of a trigonometric correction in the panoramic radiograph analysis may reduce the limitations of this 2D evaluation.
Authors: G R Janson; G De Luca Canto; D R Martins; J F Henriques; M R De Freitas Journal: Am J Orthod Dentofacial Orthop Date: 2000-09 Impact factor: 2.650
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Authors: Fabio Savoldi; Aggeliki Papoutsi; Simona Dianiskova; Domenico Dalessandri; Stefano Bonetti; James K H Tsoi; Jukka P Matinlinna; Corrado Paganelli Journal: Korean J Orthod Date: 2018-07-06 Impact factor: 1.372