Evaluation of the agreement by examiners according to classifications of third molars

Cj Lima,Mr Melo,Lc Silva,Ja Santos,Ts Santos

doi:10.4317/medoral.17483

Abstract

Objectives. This study recorded and evaluated the intra- and inter-group agreement degree by different examiners for the classification of lower third molars according to both the Winter’s and Pell & Gregory’s systems. Study Design. An observational and cross-sectional study was realized with forty lower third molars analyzed from twenty digital panoramic radiographs. Four examiner groups (undergraduates, maxillofacial surgeons, oral radiologists and clinical dentists) from Aracaju, Sergipe, Brazil, classified them in relation to angulation, class and position. The variance test (ANOVA) was applied in the examiner findings with significance level of p<0.05 and confidence intervals of 95%. Results. Intra- and inter-group agreement was observed in Winter’s classification system among all examiners. Pell & Gregory’s classification system showed an average intra-group agreement and a statistical significant difference to position variable in inter-group analysis with greater disagreement to the clinical dentists group (p<0.05). Conclusions. High reproducibility was associated to Winter’s classification, whereas the system proposed by Pell & Gregory did not demonstrate appropriate levels of reliability. Key words: Agreement, reproducibility, classifications, third molars.

Highlights

The third molars frequently present in a wide range of anatomic positions and angulations which commonly result in a high degree of dental impaction
There has been no previous research in the literature which has proved the reproducibility of such classifications nor the objectivity of their utilization as clinical and scientific parameters [7]
Fifty digital panoramic radiographs which presented at least one lower third molar with indication for surgical removal were involved in this research

Summary

Introduction

The third molars frequently present in a wide range of anatomic positions and angulations which commonly result in a high degree of dental impaction Whether it be for prophylactic, orthodontic and prosthetic reasons or for the diagnosis of several associated pathologies, the surgical removal of these teeth is one the most performed dentoalveolar procedures in oral and maxillofacial surgery [1]. Radiological individual anatomy, demographic aspects and operative factors are considered important variables to the determination of surgical difficulties and postoperative complication risks [3] These methods have been extensively adopted and applied in clinical practice and in several types of studies which have employed a range of study design, from systematic reviews to correlational prospective analysis with pre-, trans- and postoperative variables [4,5,6]. The current study aims: 1) to register the angulation, class and position of lower third molars by four groups of examiners through analysis of digital panoramic radiographs and; 2) to estimate and evaluate the agreement degree intra- and inter-group of examiners, in order to investigate the reliability of both the Winter’s and Pell & Gregory’s classifications

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Conclusion