Detection of dentine caries using the oblique lateral radiograph

The aim of the study was to evaluate the level of agreement between bitewing radiographs and oblique lateral radiographs for the diagnosis of dental caries extending into dentine, and to draw conclusions from the results as to which view is more useful.

Radiographs were selected from patients attending an orthodontic assessment clinic: 53 patients, 52% male, 48% female, aged 6-18 years old. Total 105 bitewings and 105 oblique lateral radiographs.

Contemporaneous bitewing and oblique radiographs taken over the period 1987-97 were independently assessed by two dentists for the presence of caries extending into dentine.

The agreement between the oblique lateral and the bitewing radiographs for the presence of approximal caries expressed in the form of Cohen's Kappa gave values of 0.64 for observer 1 and 0.53 for observer 2. For occlusal caries, values were 0.72 for observer 1 and 0.56 for observer 2. Kappa values for the level of agreement between observers and for the same observer on different occasions were within the range 0.5-0.95 for both types of film.

The Kappa values for the agreement between the two views as well as the intra- and inter-observer agreement and reproducibility of the oblique lateral view all fall in the range K = 0.5-0.75. Results suggested a fair to good agreement in diagnoses made using the two types of film. However, levels were lower than estimates of reproducibility reported for bitewing films alone.