title: The effect of central incisor's root proximity to the cortical plate and apical root resorption in extraction and non-extraction treatment.
abstract: OBJECTIVE
  The present study was conducted to investigate the relevance of cortical plate proximity of maxillary central incisor root, maxillary alveolar bone width, and the apical root resorption in extraction and non-extraction orthodontically treated cases. Further, the correlation between the apical root resorption and the various parameters was investigated.
  
  
  METHODS
  A total of 80 lateral head cephalographs, 40 pre-treatment and 40 post-treatment, of orthodontic subjects with a mean age of 15 years treated with fixed standard edgewise appliance were obtained. All subjects were divided into two groups as extraction and non-extraction cases. Twelve linear and three angular parameters were measured and evaluated. The paired "t"-test, Pearson's correlation coefficient, and the stepwise regression analysis were done to test the relationship between the apical root resorption and the various parameters.
  
  
  CONCLUSIONS
  The study revealed slightly greater amount of apical root resorption in extraction subjects as compared to non-extraction subjects. However, no statistically significant difference was found between the two treatment modalities. In extraction subjects, the apical root resorption was directly proportional to the pre-treatment length of maxillary central incisor and inversely proportional to the root width in apical one-third region, though there was a weak correlation. In non-extraction subjects, the pre-treatment anteroposterior position of the root apex of maxillary central incisor in the alveolar bone, in combination with its root width in the apical one-third region formed the predictive factors for the variance in the amount of the apical root resorption, though there was a weak correlation. Furthermore, the changes in the alveolar widths at the root apex and mid-root region were considered as predictive factors for the amount of apical root resorption during extraction and non-extraction treatment, respectively.
authors.affiliation: Department of Orthodontics, Babu Banarasi Das College of Dental Sciences, Lucknow, Uttar Pradesh, India.
authors.forename: Akhil
authors.initials: A
authors.lastname: Agarwal
authors.affiliation: Department of Orthodontics, Faculty of Dental Sciences, C. S. M. Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Vijay P
authors.initials: VP
authors.lastname: Sharma
authors.affiliation: Department of Orthodontics, Faculty of Dental Sciences, C. S. M. Medical University, Lucknow, Uttar Pradesh, India.
authors.forename: Gulshan K
authors.initials: GK
authors.lastname: Singh
authors.affiliation: Department of Orthodontics, Babu Banarasi Das College of Dental Sciences, Lucknow, Uttar Pradesh, India.
authors.forename: Tripti
authors.initials: T
authors.lastname: Tikku
authors.affiliation: Department of Oral Pathology, Babu Banarasi Das College of Dental Sciences, Lucknow, Uttar Pradesh, India.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Agarwal
authors.affiliation: Department of Orthodontics, Government Dental College, Jammu, Jammu and Kashmir, India.
authors.forename: Arvind
authors.initials: A
authors.lastname: Mengi
keywords: Apical root resorption; cortical plate proximity; maxillary alveolar bone width; maxillary central incisor