Simultaneous Reconstruction of Atrophic Mandible and Inferior Alveolar Nerve for Dental Implants

This is a case report of 56 year-old African-American female who presented for evaluation of left mandibular dysesthesia and atrophic mandible. She was consulted for appropriate treatments.  The patient had 2 dental implants in the left mandible with bone graft at edentulous areas #18 and #19. Postoperatively she immediately developed numbness and sharp shooting pains in her left mandible. After that, she underwent a second surgery for debridement of bone graft in the left mandible. The implants in the left mandible were left in place for 1 year and ultimately removed. The patient still complained of pain and hypersensitivity in her left lower jaw and asked for help. Materials and methods: The clinical evaluation of trigeminal nerve injuries was performed on this patient.  Clinical examinations showed atrophic edentulous areas # 18, 19 and 30 with buccal mucosal scar. The patient was positive for spontaneous pain and dysesthesia of the left lower lip. She had unpleasant altered sensation with pain sensitivity (Level C): hyperalgesia – exhibited exaggerated response to pin pick, decreased pressure (algometer) pain threshold, or decreased thermal pain threshold on test site. The sensation test of the left lower lip with a von Grey hair (Semmes-Weinstein Monofilament/pressure aesthesiometer) was utilized. The left and right lower lips were positive to the monofilament sizes 3.61 and 1.65, respectively. The two-point discrimination threshold (2PDT) was measured to reflect impaired spatial discrimination acuity. The preoperative static 2PDT of left and right lower lips were 13 mm and 6 mm, respectively. The diagnostic nerve block of the left inferior alveolar nerve was judiciously employed to weigh the relative contributions of peripheral and central factors to the pain. The peripheral nerve block proximal to the site of injury significantly decreased the pain complaint. Therefore peripheral factors were accepted as responsible for the discomfort. The left inferior alveolar nerve injury was a diagnosis with left atrophic mandible. The patient underwent microreconstructive inferior alveolar nerve surgery and bone graft reconstruction. The sequence of steps in the cascade was exposure, external neurolysis, internal neurolysis, resection of neuroma or fibrosed segment, mobilization, approximation, coaptation, direct neurorrhaphy, interpositional nerve graft and nerve transfer. Results: After 9 months of left inferior alveolar nerve repair, patient underwent placement of 2 dental implants at areas # 18 and 19 without any complications. After 17 months of left inferior alveolar nerve repair, patient continued having normal wound healing. Patient reported 60% sensation of pin prick and light touch on the left V3 region compared to the right. There was no dysesthesia or spontaneous pain at left lower lip. Directional brush stroke and sharp/dull were intact bilaterally. The postoperative static 2PDT of left and right lower lips were 15 mm and 8 mm, respectively. Conclusion: Simultaneous reconstruction of atrophic mandible and inferior alveolar nerve could be considered prior to placement of dental implants.