Does the Use of Cone Beam CT for the Removal of Wisdom Teeth Change the Surgical Approach Compared with Panoramic Radiography?

Statement of Purpose:

The aim of the present study was to evaluate if the additional information provided by CBCT images influences the surgical strategy in the treatment of patients with impacted mandibular third molars in high-risk cases. More specifically, it considered whether there is any difference in risk assessment for IAN injury when using CBCT and panoramic radiography and whether this results in a different surgical approach.

This study evaluated the role of cone beam computed tomography (CBCT) in the treatment of patients with impacted mandibular third molars at increased risk of inferior alveolar nerve (IAN) injury. Subjects with an increased risk of IAN injury, as diagnosed on panoramic radiographs, were enrolled in this study and underwent additional CBCT imaging.

Materials and Method:

The study sample consisted of 52 impacted third molars from 36 patients (20 women and 16 men) with an average age of 24.6 years (range 19–33 years). Three board certified oral maxillofacial surgeons independently evaluated the panoramic radiographs of all patients in randomized order followed by the CBCT images of the same teeth on a 17 in. PC monitor. The surgeons were asked to answer questions pertaining to removal of buccal bone, elevator placement, need for tooth sectioning, direction of tooth removal, prediction of nerve Injury, integrity of Inferior Alveolar canal and treatment planning based on the panoramic radiographs and CBCT images provided.

Statistical analyses

The McNemar test  and the Wilcoxon signed ranks tests were used.

All statistical analyses were performed using SPSS 22.0 statistical software.

Results

There were inconsistencies across the surgeons for how well CBCT findings matched panoramic radiographic findings. Item 1 (removal of buccal bone) showed no difference for surgeons 1 and 3 (p > 0.05 for each), but a significant difference between CBCT and PAN for surgeon 2 (p = 0.016). Item 3b (removal of extra bone safely after tooth sectioning) revealed differences between CBCT and PAN for surgeon 1 (p = 0.004) and surgeon 2 (p = 0.021), but no difference for surgeon 3. Item 6 (Integrity of alveolar canal) showed a significant difference between the methods for surgeon 2 (p = 0.001) and surgeon 3 (p = <0.001), but no difference for surgeon 1. Item 4 (direction of tooth removal) showed differences for surgeon 1 (p =0.027) and surgeon 3 (p < 0.001), but no difference for surgeon 2. For item 7 (treatment plan) there was only a difference between CBCT and PAN for surgeon 1 (p = 0.040) but no differences for surgeons 2 and 3. Items 2 (elevator placement), 3a (tooth sectioning), and 5 (prediction of nerve injury) showed no significant difference between CBCT and PAN for any of the surgeons.

Conclusion:
The results of this study show that CBCT imaging does not change the surgical planning and technique when compared with panoramic radiography. To prove the usefulness of CBCT in reducing the prevalence of IAN injury, a large randomized clinical trial is warranted with larger sample size uniformly distributed in groups undergoing CBCT imaging and panoramic radiography. Due to ethical issues, such a study cannot be carried out.

In the authors’ opinion, there seems to be no statistical difference with treatment planning and surgical technique when compared to panoramic radiographs neither was there any difference in risk assessment for IAN injury.

Reference:

1. Assael LA. The presurgical workup: how much is enough? JOMS 2002: 60: 977.

 

1. Ghaeminia, Meijer, Soehardi , Borstlap , Mulder, Vlijmen, Berge, Maal : The use of cone beam CT for the removal of wisdom teeth changes the surgical approach compared with panoramic radiography: a pilot study. IJOMS. 2011; 40: 834–839.