Letter to the Editor

Abstract

To the Editor: Recently, an interesting research article by Romanos et al1 was published that related the frequency, and the importance, of the mandibular incisive canal (MIC) and its nerve in preoperative planning for implant surgery. For most surgeons, the anatomy and content of the MIC are controversial,2–5 and in many books or articles, there is no reference to its existence,6–8 whereby the anterior mandible region is considered a safe area for implant placement. However, the high rate of incidence reported in anatomical and imaging studies conclude that the MIC (and its nerve) corresponds to a constant anatomical structure rather than an anatomical variation,5,8 with an origin at the level of mental foramen, term at the apex of the mandibular lateral incisor, and an average diameter between 1.8 (±0.5)5,9 and 1.48 (±0.57) mm.1 Neurosensory disorders have been reported after installation of implants in the anterior region of the mandible.6,10,11 Other complications such as bruising and swelling during or after surgical procedures, or even a traumatic neuroma,10 can arise due to direct7,10 or indirect6,9 trauma of the canal or it's nerve. Another complication is the failure of osseointegration because of the migration of soft tissue around the implant.7 The high detection rate of MIC by cone beam computed tomography indicates the high value of the analysis for preoperative surgical procedures in the anterior mandibular area.3 Current evidence has described the microsurgical approach by endoscopic visualization of neurovascular structures in oral surgery and implantology, including MIC and its nerve,2,3,12 as we can see in Figure 1, which uses an immersion endoscopic technique for precise location and removal of the mandibular incisive nerve after implant placement. Mandibular incisive nerve and other nerves of the maxillofacial area have rarely been seen with this quality and amplification.Fig. 1: A, Evaluation of the visibility and the course of the mandibular incisive canal using cone-beam computed tomography. B, Intraoperative visualization by immersion endoscopy (Karl Storz 1.9mm diameter) of mandibular incisive nerve (terminal branch) prior to resection in the area of implant placement. Red arrow indicates the osseous border of the mandibular incisive canal and white arrow its nerve.The presence, and anatomy, of the MIC and its nerve should not be ignored in the planning of implants and other surgical procedures in the anterior mandible. This could play a fundamental role in avoiding any risk of neurovascular damage and obtaining successful osseointegration. We agree with Romanos et al1 that there is no doubt that orthopantomographs underestimate the real presence of MIC and a more precise examination should be taken into consideration when surgical procedures in this anatomical area have to be performed. Cone beam computed tomography is recommended to identify these structures before any surgical procedure in this region, along with the use of intraoperative endoscopy for a successful outcome (see Fig. 1 A and B).