IADR Abstract Archives
Reliability of Panoramic-radiographs To Determine Third-molar’s Vertical Position From Inferior-alveolar-canal.
Objectives: Cone-beam-computed- tomography (CBCT) has been useful in providing insights of relevant anatomy prior to surgical procedures, including the assessment of the proximity of impacted mandibular-third-molar to the inferior-alveolar-canal (IAC). It is important to understand the reliability of conventional panoramic- radiograph in the assessment of this criterion since it is more commonly used as first line radiographic approach due to its availability and lower radiation dose. Objective of study: This study is aimed to investigate the reliability of conventional panoramic-radiograph in the evaluation of the proximity of impacted mandibular-third-molar root tip to the IAC by correlating the results with CBCT.
Methods: A total of 65 root tips of impacted mandibular-third-molars that had both panoramic-radiographs and CBCT images were included in this retrospective study. Two trained observers participated in all image evaluations. A prepared standard 1-cm ruler was used to measure the proximity of the third-molar root apices to the IACs. Measurements recorded in this study were categorized into positive (root apex above a roof of IAC), zero (root apex was superimposed on IAC) and negative (root apex below a roof of IAC) measurements. Data analysis was done using student t-test.
Results: From this study, both observers showed significant difference between panoramic-radiographs and CBCT images when measuring the vertical position between the third-molar root apices to the roof of IACs (P<0.001). Eleven out of 44 roots that were located within the canal from panoramic-radiographs were actually located superior to the canal on CBCT panoramic reconstruction slices.
Conclusions: The low reliability of panoramic-radiograph to assess the vertical proximity between these two anatomical structures suggests the importance of additional assessment with CBCT especially in cases where panoramic-radiograph suggests presence of third-molar root below the roof of the IAC.
Methods: A total of 65 root tips of impacted mandibular-third-molars that had both panoramic-radiographs and CBCT images were included in this retrospective study. Two trained observers participated in all image evaluations. A prepared standard 1-cm ruler was used to measure the proximity of the third-molar root apices to the IACs. Measurements recorded in this study were categorized into positive (root apex above a roof of IAC), zero (root apex was superimposed on IAC) and negative (root apex below a roof of IAC) measurements. Data analysis was done using student t-test.
Results: From this study, both observers showed significant difference between panoramic-radiographs and CBCT images when measuring the vertical position between the third-molar root apices to the roof of IACs (P<0.001). Eleven out of 44 roots that were located within the canal from panoramic-radiographs were actually located superior to the canal on CBCT panoramic reconstruction slices.
Conclusions: The low reliability of panoramic-radiograph to assess the vertical proximity between these two anatomical structures suggests the importance of additional assessment with CBCT especially in cases where panoramic-radiograph suggests presence of third-molar root below the roof of the IAC.