External Marker in Bisecting-Angle-Technique: A New Approach to Minimize Dental Radiographic Error

Bisecting-angle-technique is a method  used  to improve  patient  comfort  during periapical radiography. This technique is usually  performed without  X-ray beam aiming device and has been commonly associated with dental radiographic error. The use of external marker as a beam  aiming device  in bisecting-angle-technique is potentially  effective to reduce  the number  of errors occurring  during periapical radiography. In this study, 240 periapical radiographs were taken by undergraduate dental  students.  Periapical  radiographs were  taken  using  traditional  method  of bisecting-angle-technique (BAT), bisecting-angle-technique with the use of external marker  (BAT-M) and  the  standard  method  in periapical radiography; paralleling technique (PT). All radiographic images were evaluated and errors were classified and tabled according to the type and number of errors. Chi-square test was used to compare the total number of radiographic errors made using these three techniques. One  of the most common errors with BAT was cone  cut error (13.8%). This error had been  markedly  reduced to 1.3% and 2.5% by implementation of BAT-M and PT, respectively.  The total number of errors was also found to be significantly lesser for BAT-M compared to BAT, p< 0.05.