In certain patients, the mandibular canal cannot be clearly visualized in preoperative radiographic studies, as observed in the present case.
To ensure surgical safety, periapical radiographs (PAR) were obtained at multiple stages of the drilling sequence.
An initial PAR at 7 mm depth confirmed the possibility of safely advancing an additional 3 mm, while a subsequent PAR at 10 mm verified that further preparation could proceed without risk of injury to the inferior alveolar nerve (IAN).
Implementing sequential PAR assessments during osteotomy preparation provides a reliable intraoperative protocol to reduce uncertainty, enabling the selection of the longest feasible implant while preserving IAN integrity.