Nerve Damage Assessment Following Implant Placement in Human Cadaver Jaws: An Ex Vivo Comparative Study
The present study compared the use of cone beam computerized tomography (CBCT) images and intra-oral radiographs in the placement of final implant drills in terms of nerve damage to cadaver mandibles. Twelve cadaver hemimandibles obtained from 6 cadavers were used. Right hemimandibles were imaged using peri-apical radiography and left hemimandibles using CBCT, and the images obtained were used in treatment planning for the placement of implant drills (22 for each modality, for a total of 44 final drills). Specimens were dissected, and the distances between the apex of the final implant drill and the inferior alveolar neurovascular bundle and incisive nerve were measured using a digital calliper. Nerves were assessed as damaged or not damaged, and the Chi-square test was used to compare nerve damage between modalities (P < 0.05). Nerve damage occurred with 7 final drills placed based on peri-apical radiography (31.8%) and 1 final drill placed using CBCT images (4.5%). The difference in nerve damage between imaging modalities was statistically significant (P = 0.023), with CBCT outperforming intraoral film in the placement of final implant drills ex vivo. In order to prevent nerve damage, CBCT is recommended as the principal imaging modality for pre-implant assessment.

(a) Intra-oral peri-apical radiography of the anterior foraminal region of an edentulous cadaver mandible section before implant placement. (b) Intra-oral peri-apical radiography of the premolar region of an edentulous cadaver mandible section before implant placement.

Cross-sectional cone beam computerized tomography image of an edentulous cadaver mandible section and available bone measurement obtained by built-in measurement tool.

Damage to the inferior alveolar nerve in right mandibular section is shown by a dissection microscope Zeiss (Carl Zeiss Inc., Jena, Germany) with magnification ×4.0.

Damage to the thin branches of incisive nerve structures in right mandibular section is shown by a dissection microscope Zeiss (Carl Zeiss Inc., Jena, Germany) with magnification ×4.0.
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