Influence of Acquisition Parameters on the Evaluation of Mandibular Third Molars Through Cone Beam Computed Tomography

• Published in: Oral surgery, oral medicine, oral pathology and oral radiology Vol. 124; no. 2; pp. 183 - 190
• Main Authors: Lagos De Melo, Larissa Pereira, Oenning, Anne Caroline Costa, Nadaes, Mariana Rocha, Nejaim, Yuri, Neves, Frederico Sampaio, Oliveira, Matheus Lima, Freitas, Deborah Queiroz
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-08-2017
• Subjects: Cone-Beam Computed Tomography - methods; Dentistry; Humans; In Vitro Techniques; Molar, Third - diagnostic imaging; Radiation Dosage; Surgery; Tooth, Impacted - diagnostic imaging; Diagnostic Imaging; Molar; Third; Cone-Beam Computed Tomography
• ISSN: 2212-4403; 2212-4411
• DOI: 10.1016/j.oooo.2017.03.008

Abstract Objectives To assess the influence of cone-beam computed tomography (CBCT) acquisition parameters on the evaluation of mandibular third molars and their relation to the mandibular canal. Study design Eight dry human mandibles with thirteen mandibular third molars were scanned with one CBCT unit. Voxel size (0.2 and 0.3 mm), field of view (FOV) size (12x8.5cm and 5x5cm), and number of basis images (450 and 720) were the variables studied. Two examiners evaluated the images, and the resulting data was compared through McNemar, McNemar-Bowker, and Student’s t tests. Additionally, dosimetry was determined for all protocols tested and radiation doses were compared through ANOVA. Results The variables did not influence third molar evaluation, except for the voxel size when assessing contact between tooth and canal (p= 0.021). While FOV and number of basis images affected radiation dose, voxel size did not. Conclusion FOV size and number of basis images did not influence the evaluation of third molars and their relation to the mandibular canal in the CBCT unit used. Conversely, smaller voxel size affected the assessment of contact between the tooth and the mandibular canal. In units in which voxel size does not influence radiation dose, the most appropriate CBCT protocol is the one using a smaller voxel size and delivering the lowest radiation dose to the patient.