We read the article ‘Rehabilitation of edentulous posterior atrophic mandible: inferior alveolar nerve lateralization by piezotome and immediate implant placement’ by Fernández Díaz & Naval Gías with great interest, and we congratulate the authors for their review of inferior alveolar nerve lateralization (IANL) and for describing the challenges in re-using an updated technique.
The use of piezosurgery is an appealing concept in maxillofacial surgery due to the frequent proximity of the bone surgical site to the nerve and/or vascular tissues; many studies have suggested this application in implant surgery, and have reported satisfactory in vivo and in vitro results compared with the bur technique.
In the discussion section, Fernández Díaz and Naval Gías refer to the common habit of the surgeon to choose techniques based on their own experience. We partially agree with this concept, as young surgeons and researchers often introduce new techniques or use validated theories from other medical disciplines to find better postoperative outcomes; hence this appears to be a related condition, more due to the specific personal characteristics of some surgeons than to a common habit.
Fernández Díaz and Naval Gías discuss mandibular atrophy, a common case in prosthetic dentistry, and refer to the occurrence of vertical bone resorption and postoperative infections due to wound dehiscence as complications in mandibular bone grafts that could suggest the use of IANL to obtain the needed vertical bone instead. They also relate the use of a sandwich technique as a key factor in decreasing the occurrence of such situations. With the evidence of many studies, we think that the type and origin of the bone graft have a strong influence on graft resorption, and in recent years many authors have reported better outcomes with calvarial grafts compared with iliac crest grafts in the rehabilitation of mandibular atrophy.
I turriaga and R uiz determined a crestal height reduction of 1.5–2.5 mm in 6% of 233 dental implants inserted on calvarial grafts in 58 patients.
Hence mandibular grafts are still a matter of interest in maxillofacial surgery, and the indication for and choice between IANL and graft appears to be the target to focus on, rather than the techniques themselves, which have both been shown to be reliable.We recently used the IANL for a different reason: a 48-year-old man was referred due to IAN hypoesthesia after implant surgery on the posterior mandible. We used the preoperative and postoperative trigeminal evoked potential to assess neurosensory function. After a panoramic radiograph and computed tomography (CT) scan ( Fig. 1 ), it was discovered that the implant fixture interrupted the IAN.A simple implant removal with counter-torque ratchet technique or high speed bur could have caused further damage to the nerve during implant removal, due to the spiral shape of the implant. Hence IANL was performed under general anesthesia to obtain a correct lateralization of the IAN during implant removal. Differently to Fernández Díaz and Naval Gías, we achieved a bevel shape on the contours of the osteotomy section to obtain an improved direct view of the mandibular nerve and to better place the cortical outer bone after IANL ( Fig. 2 ).
