Imaging Sci Dent.  2016 Mar;46(1):17-24. 10.5624/isd.2016.46.1.17.

A posteriori registration and subtraction of periapical radiographs for the evaluation of external apical root resorption after orthodontic treatment

Affiliations
  • 1Department of Dental Radiology, School of Dentistry, Ponta Grossa State University, Ponta Grossa, Paraná, Brazil. elianekreich@gmail.com
  • 2Department of Pediatric Dentistry, School of Dentistry, Ponta Grossa State University, Ponta Grossa, Paraná, Brazil.
  • 3Department of Orthodontics, School of Dentistry, Ponta Grossa State University, Ponta Grossa, Paraná, Brazil.
  • 4Department of Dental Radiology, School of Dentistry, State University of São Paulo, São José dos Campos, São Paulo, Brazil.

Abstract

PURPOSE
This study employed a posteriori registration and subtraction of radiographic images to quantify the apical root resorption in maxillary permanent central incisors after orthodontic treatment, and assessed whether the external apical root resorption (EARR) was related to a range of parameters involved in the treatment.
MATERIALS AND METHODS
A sample of 79 patients (mean age, 13.5±2.2 years) with no history of trauma or endodontic treatment of the maxillary permanent central incisors was selected. Periapical radiographs taken before and after orthodontic treatment were digitized and imported to the Regeemy software. Based on an analysis of the posttreatment radiographs, the length of the incisors was measured using Image J software. The mean EARR was described in pixels and relative root resorption (%). The patient's age and gender, tooth extraction, use of elastics, and treatment duration were evaluated to identify possible correlations with EARR.
RESULTS
The mean EARR observed was 15.44±12.1 pixels (5.1% resorption). No differences in the mean EARR were observed according to patient characteristics (gender, age) or treatment parameters (use of elastics, treatment duration). The only parameter that influenced the mean EARR of a patient was the need for tooth extraction.
CONCLUSION
A posteriori registration and subtraction of periapical radiographs was a suitable method to quantify EARR after orthodontic treatment, and the need for tooth extraction increased the extent of root resorption after orthodontic treatment.

Keyword

Root Resorption; Orthodontics; Subtraction Technique; Image Processing, Computer-Assisted; Tooth Extraction

MeSH Terms

Humans
Image Processing, Computer-Assisted
Incisor
Orthodontics
Root Resorption*
Subtraction Technique
Tooth Extraction
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