The canalis sinuosus (CS) and its accessory canals (ACs) are anatomical structures in the anterior maxilla. These structures are often neglected when planning implant surgery because their clinical significance is still not well-defined. After a retrospective evaluation of 194 patients rehabilitated with dental implants in the anterior maxilla, 3 patients were identified who presented unexpected chronic neurosensory disturbances without any clinical signs supportive of implant failure. Tomographic assessment using cone-beam computed tomography (CBCT) revealed the invasion of the CS and ACs by dental implants, which appeared to explain the patients' symptoms. The purpose of this report was to familiarize practicing dentists and specialists with the CS and its ACs. Unanticipated neurosensory symptoms after implant placement in the anterior maxilla justify the use of CBCT to rule out an injury to this neurovascular bundle.