The radiographic determinability of the distance between the pulp horns in the permanent first and second molar teeth

The purpose of this study was to investigate the determinability of the distance between the pulp horns (PHD) radiographically under routine clinical conditions. This study was carried out on 36 maxillary and 28 mandibular first and second molars which were extracted because of periodontal diseases. Prior to extraction two radiographs were taken from each tooth, one using the bisecting-angle technique and the other by using the bitewing technique. After the extractions, each tooth was burred on the distal and mesial approximal surfaces and pulp horns were found. The distance between the pulp horns was measured (anatomical measurement). Using bisecting-angle and bitewing radiographs, 11 clinicians measured the PHD values of each tooth (radiographic measurement). In our study the residual error in mandibular molar teeth was statistically lower when compared to maxillary molar teeth (p < 0.01). Statistically significant differences were found between anatomic and radiographic measurements (p< 0.01) in maxillary molars. No statistically significant difference was found between anatomical and bisecting-angle measurements in mandibular first and second molars. As a result, it is concluded that bisecting-angle techniques are useful in correctly determining the PHD values in mandibular molars. (J. Oral Sci. 40, 143-146, 1998)