IADR Abstract Archives

Volumetric Evaluation of Root Resorption during Orthodontic Treatment with Extractions

Objectives: Root resorption (RR) of maxillary incisors has been shown to occur during orthodontic treatment. Traditionally, RR has been quantified using 2-dimensional images. However, determination of volumetric changes associated with RR is clinically more relevant than linear changes.

Objectives: To determine the loss of root volume of maxillary incisors in patients who have received orthodontic treatment with and without extractions.
Methods: Records of 215 consecutively treated patients who received orthodontic treatment with or without extractions were obtained for this study. Pre- and Post- treatment cone beam computed tomography (CBCT) were reconstructed. Pre- and Post- treatment root lengths of maxillary central and lateral incisors were measured in CBCT using Invivo 5.4. Pre- and Post- treatment tooth volumes of maxillary central incisors were determined using segmentation software ITK-SNAP 3.8.0.
Results: Maxillary incisors in the extraction group displayed a greater root length loss during treatment compared to non-extraction group. Lateral incisors in the extraction group exhibited the greater root length loss during treatment. Difference in the numbers of incisors experiencing greater than 25% linear root loss and less than 25% loss was not significant (Table 1). Loss of incisor root volume in the extraction group was slightly higher than non-extraction group. There was no statistically significant difference in the number of incisors exhibiting root volume loss of greater than 25% between the extraction and non-extraction groups (Table 2). After adjusting for initial length, treatment duration, tooth, sex, race, bracket type, and malocclusion status, reduction of root length in extraction group was 0.37 mm greater than patients without an extraction (p = 0.003) and the difference in volume change between extraction and no extraction group was not significant ( p = 0.29).
Conclusions: Even though the amount of root resorption is more in the extraction group, we could not find a significant difference in the loss of root volume between two groups
IADR/AADR/CADR General Session
2020 IADR/AADR/CADR General Session (Washington, D.C., USA)
Washington, D.C., USA
2020
1804
Craniofacial Biology Research
  • Patel, Jaykishan  ( University of Nebraska Medical Center , Lincoln , Nebraska , United States )
  • Kim, Sung  ( University of Nebraska Medical Center College of Dentistry , Lincoln , Nebraska , United States )
  • Premaraj, Thyagaseely  ( University of Nebraska Medical Center , Lincoln , Nebraska , United States )
  • Premaraj, Sundaralingam  ( University of Nebraska Medical Center , Lincoln , Nebraska , United States )
    • None
    Poster Session
    Orthodontic Research
    Table 1. Number of Patients Experiencing ≥25% Loss of Root Length
    GroupMaxillary Incisor<25%≥25%p-value
    Extraction    
     Right Lateral87(94.57%)5(5.43%)0.11
     Right Central87(94.57%)5 (5.43%)0.27
     Left Central86(93.48%)6 (6.52%)0.16
     Left Lateral90(97.83%)2 (2.17%)1
    Non-Extraction    
     Right Lateral95 (98.96%)1 (1.04%)0.11
     Right Central94 (97.92%)2 (2.08%)0.27
     Left Central94 (97.92%)2 (2.08%)0.16
     Left Lateral93 (96.88%)3 (3.13%)1

    Table 2. Number of Maxillary Central Incisors Experiencing ≥25% Volumetric Loss
    Group Maxillary Incisor

    		<25%≥25%p-value
    Extraction     
     Right Central 90 (97.83%)2 (2.17%)1
     Left Central 91 (98.91%)1 (1.09%)0.49
    Non-Extraction

    		    
     Right Central 94 (97.92%)2 (2.08%)1
     Left Central 96 (100.0%)0 (0.00%)0.49