Evaluation of the Validity and Reliability of Measurements Made on Intra-oral Images of the Dental Arches Compared to Those Made on Poured Plaster Models in the Assessment of Tooth-size-arch-length-discrepancy, Bolton's Analysis and Little's Index of Irregularity.

Detailed Summary

The general trend in the orthodontic practice is to become digital in many aspects. Since 1980s, digital photographs have been available and they play a principal role in the orthodontic practice for documentation and diagnosis purposes. Now photographs have an important role in teaching, scientific research and medical examination. Successful orthodontic treatment is based on a comprehensive diagnosis and treatment planning. A few of the fundamental factors in the diagnosis are the spacing condition, tooth size, arch form and dimensions, as well as the tooth-arch discrepancies. Intraoral photographs' major role is to enable orthodontists to document and analyze the occlusal relationships as well as the dental and soft-tissue features in order to arrive at a good diagnosis and an appropriate treatment plan. In 1975, Robert Little developed Little's irregularity index (LII). The index was proposed to assess teeth irregularity, crowding, relapse, and alignment of anterior teeth as it measured the linear displacements in the horizontal plane between contact points of anterior teeth, ignoring vertical displacement, from mesial surface of one canine to the contra-lateral one. The sum of the 5 liner measurements of displacements was the LII score. The higher the index value, the more severe irregularity of the teeth was. LII has been originally developed for mandibular incisors to study relapse; however, researchers have used it to assess upper and lower incisors irregularity Tooth-size-arch-length discrepancy (TSALD) is widely used on study models to assess the level of harmony between tooth size and the supporting basal bone. Bolton analysis is another important measurement used to identify disharmony between maxillary and mandibular tooth size which is considered an important factor to ensure the success of orthodontic treatment. With the application of the suggested formulas, the overall ratio should be 91.3% (±1.91) and the partial (anterior) ratio should be 77.2% (±1.65). The validity and reliability of performing the above mentioned analyses on images taken of the dental arches have not been evaluated yet in the literature. This is the aim of the current project.

Study Details

Timeline

Interventions