Inferior Alveolar Nerve Function Research Articles

Comprehensive Long-Term Outcomes Following Mandibular Distraction Osteogenesis.

To describe long-term outcomes and complications following mandibular distraction osteogenesis (MDO) in a diverse patient cohort. Cross-sectional study. Single tertiary-care pediatric center. Forty-eight patients previously undergoing MDO with minimum 4-year follow-up. Respiratory outcomes, feeding patterns, dental development, motor/sensory nerve function, temporo-mandibular joint function, and postsurgical scarring. Forty-six patients with a median age of 7 years were evaluated. Of 20 nonsyndromic patients, none required additional airway procedures, none required continuous positive airway pressure (CPAP) during sleep, and 19 (95%) fed exclusively by mouth. Among 26 syndromic patients, 7 (27%) required CPAP and 8 (31%) were tube fed. Permanent first molar differences were seen in the majority of subjects; patterns of damage interfering with function were more common in syndromic (13/28, 46%) compared to nonsyndromic (5/24, 21%; P = .014) subjects. MDO prior to age two was associated with more frequent and worse dental damage (P = .001). Inferior alveolar nerve and marginal mandibular nerve function were fully intact in 37 (80%) and 39 (85%) of patients, respectively. Three patients (6%), all with associated genetic syndromes, demonstrated severe nerve impairment. By the Vancouver scar scale, ≥ 80% of surgical scars were rated in the most favorable category for each quality assessed. Temporomandibular joint dysfunction was rare. MDO shows highly favorable long-term respiratory, feeding, nerve, and scar outcomes in nonsyndromic patients, although permanent molar changes not precluding tooth viability are commonly seen. Patients with associated syndromes demonstrate respiratory and feeding benefits, but higher rates of dental and nerve abnormalities.

Buccally or Lingually Tilted Implants in the Lateral Atrophic Mandible: A Three-Year Follow-Up Study Focused on Neurosensory Impairment, Soft-Tissue-Related Impaction and Quality of Life Improvement.

Background and Objectives: In the severely resorbed posterior mandible, implant placement requires either bone regenerative procedures, subperiosteal implants or short implant placement with drawbacks including morbidity and increased treatment costs and duration. To overcome these inconveniences, some unconventional alternatives have been suggested, such as buccally or lingually tilted implants in the lateral mandible, bypassing the inferior alveolar nerve. The aim of the present retrospective study was to evaluate the three-year survival rate of implants inserted in the posterior atrophic mandible, bypassing the inferior alveolar nerve. The assessment was focused on the occurrence of postoperative complications related to neurosensory impairment and soft tissue impaction, as well as overall improvement in quality of life. Materials and Methods: Patients with severe bone atrophy in the lateral area of the mandible were included in the present study. Only the implants tilted either buccally or lingually to bypass the inferior alveolar nerve were analysed. The relation between peri-implant soft tissue and the healing abutment was assessed and a secondary revision surgery was performed when indicated. The Semmes-Weinstein pressure neurological test was used for qualitative assessment of inferior alveolar nerve function and the Geriatric Oral Health Assessment Index (GOHAI) was used for evaluating Oral-Health-Related Quality of Life (OHRQoL). Results: Fourteen implants were placed in nine patients during the evaluation period. Survival rate was 100%, temporary paraesthesia occurred in one patient and a limited definitive paraesthesia was seen in another patient. Mild or significant discomfort related to soft tissue impaction with healing abutment was observed in six out of nine patients. A statistically significant OHRQoL improvement was observed in all patients. Conclusions: Despite the limited number of patients and observation time, insertion of implants buccally or lingually bypassing the inferior alveolar nerve is a predictive treatment option for patients with severe bone atrophy in the posterior mandible.

TREATMENT INJURY OF THE INFERIOR ALVEOLAR NERVE DURING IMPLANT PLACEMENT USING MAGNETIC-LASER THERAPY

Objective: The aim of this study was to assess the effectiveness of magnetic-laser therapy in complex treatment of neuropathy after dental implantation Materials and methods: The present study is based on the results of the analysis of clinical, instrumental and radiation studies of 27 patients, with post-traumatic neuropathy inferior alveolar nerve. Diagnosis of damage to the inferior alveolar nerve was based on the clinical manifestations of neuropathy (pain, paresthesia, loss of sensation, etc.). The study of the sensitivity of the skin of the lower lip and chin in the segment of the inferior alveolar nerve dysfunction and in the symmetrical segment performed using sensory tests. Conservative treatment included: Anti-infl ammatory, analgesics, antioxidants, B complex of the vitamins group. Magnetic-laser therapy included in a conservative treatment complex for patients. To conduct a comparative analysis of effectiveness of magnetic-laser therapy, two groups were formed: Patients fi rst group (n= 14), whose treatment complex included magnetic- laser therapy, Patients second group (n= 13), whose treatment complex did not include magnetic-laser therapy. Results: Most patients after implant placement complained of pain of varying degrees, a decrease or lack of sensitivity of the lower lip, chin skin, and the mucous membrane of the alveolar process of the lower jaw, paresthesia or hyperesthesia. Some patients did not have pain, however noted that sensitivity disorders have a negative effect ongeneral well-being and interfere with work. When comparing 2 group the best pain relief was patients first group. The average area of skins sensory impairment in patients was mean 9.4cm2. Patients first group complete recovered function of inferior alveolar nerve within mild 1 month, patients in the second group, whose treatment complex did not include magnetic laser therapy, fully recovered function of inferior alveolar nerve within mild 2 months. Conclusion: Thus, the inclusion of magnetic laser therapy in the post-implantation traumatic neuropathy treatment shows the biostimulation effect, complex allows to reduce the recovery time of functional disorders of the inferior alveolar nerve, to reduce the area of skins sensory impairment and increase the effectiveness of treatment.

Fully Guided Tooth Bud Ablation in Pigs Results in Complete Tooth Bud Removal and Molar Agenesis

Fully guided microwave tooth bud ablation has the potential to become a minimally invasive means for managing third molars in adolescent patients. If developed, this new modality could provide improved outcomes and reduced complications compared to traditional third molar management strategies. The purpose of this 28-day longitudinal characterization study was to determine if the healing response following fully guided microwave ablation of secondmolar tooth buds in juvenile pigs would result in the complete removal of targeted tooth bud tissues, molar agenesis, and no significant collateral tissue damage. Investigators performed fully guided microwave ablation on 24 mandibular secondmolar tooth buds (#18 and #31) in seven-week-old pigs. Postablation healing assessment consisted of radiographic and histological evaluation of 3 subcohorts (consisting of 4 animals each) at 7-, 14- and 28-days post ablation. Controls were untreated, opposing maxillary secondmolar tooth buds. Neurological assessment was performed to determine if there was any detectible loss of inferior alveolar nerve function. Healing processes were nearly complete at 28days post ablation. While one tooth bud was identified as partially ablated at 14days post treatment, all treated tooth bud tissues were replaced with trabecular new bone formation by the end of this study. There was no detectible loss of inferior alveolar nerve function. The thermal dosing strategy used in this study appears to deliver prescribed ablation volumes and-within the context of this animal model-there was no detected collateral tissue damage. The results of this study confirm the hypothesis that healing processes following fully guided tooth bud ablation resulted in removal of targeted tooth bud tissues, complete molar agenesis, and trabecular new bone growth at 28-days post treatment.

Evaluation of Neurosensory Deficits Following the Use of Computer Assisted Surgical Guide for Inferior Alveolar Nerve Bypass versus Inferior Alveolar Nerve Lateralization (Randomized Controlled Trial)

Objective : To evaluate the neurosensory function of inferior alveolar nerve following the placement of animplant with Bypassing versus lateralization method. Methods : Twenty six partially edentulous patientswere selected and equally grouped into 2 groups. In 1st group: implants placed by inferior alveolar nervelateralization with Piezosurgery, while in 2nd group implants placed by computer guided surgical stentto bypass the inferior alveolar nerve. Then the neurosensory deficits are evaluated by subjectively andobjectively tests. Assessment occurred at period intervals 2 ,8 & 24 weeks postoperatively. Results: therewas statistically significant difference between the IANL & IANB especially at the early post-operativefollow up, but with time there was no statistically significant difference. Conclusion: The inferior alveolarnerve lateralization technique has a higher initial rate of sensory dysfunction than the nerve bypassingtechnique with the aid of computer guided stent.

Assessment of Post-Traumatic and Postoperative Inferior Alveolar Nerve Function in Mandibular Angle Fracture

Assessment of Post-Traumatic and Postoperative Inferior Alveolar Nerve Function in Mandibular Angle Fracture

Somatosensory changes in Chinese patients after coronectomy vs. total extraction of mandibular third molar: a prospective study

ObjectivesThis study aimed to quantitatively compare the somatosensory function changes of inferior alveolar nerve (IAN) after mandibular third molar extraction with a surgery protocol of coronectomy, as opposed to the conventional method.Materials and methodsPatients with a lower third molar directly contacting IAN were recruited and assigned either to a test group (coronectomy group) or a control group (conventional extraction). A standardized quantitative sensory testing (QST) battery was performed for four times: one week before surgery and the second, seventh, and 28th days after surgery. Z-scores and the loss/gain coding system were applied for each participant.ResultsA total of 140 molars (test group: n = 91, control group: n = 49) were enrolled. The sensitivity of the mechanical detection threshold (MDT) and pressure pain threshold (PPT) significantly increased after surgery more than before surgery in both groups (P ≤ 0.001). After the surgery, the sensitivities of the cold detection threshold (CDT), cold pain threshold (CPT), and heat pain threshold (HPT) were significantly higher in the test group than in the control group (P ≤ 0.027). The risk of IANI was significantly larger (P = 0.041) in the test group than in the control group.ConclusionsQST was a sensitive way to detect somatosensory abnormalities even with no subjective complaint caused by surgery. Coronectomy had less influence on IAN function than conventional total extraction.Clinical relevanceThe somatosensory function changes after mandibular third molar extraction were quantitatively studied, and coronectomy was proved a reliable alternation to reduce IAN injury rate.

Mandibular reconstruction: a review

Mandibular defects may occur from maxillofacial injury, inflammatory disease, benign or malignant tumour resections and osteoradionecrosis. Mastication, speech and facial disfigurement are often severely compromised without reconstruction leading to poor quality of life. The goal of mandibular reconstruction is to restore facial form and function, repair of mandibular continuity and soft tissue reanimation. Implant insertion should be feasible to allow occlusal rehabilitation and if possible the inferior alveolar nerve function should be restored. Mandibular reconstruction principles and techniques have evolved dramatically over the years. Refinements in techniques continue to improve patient quality of life. This paper reviews short history, current techniques and few promising future endevours related to mandibular reconstruction.
 Update Dent. Coll. j: 2019; 9 (2): 50-54

Effects of inferior alveolar nerve rupture on bone remodeling of the mandible

Although various animal studies have indicated that sensory nerves played an important role in bone metabolism and nerve injury could impair the process of bone remodeling, the actual effect of sensory nerve rupture on human bones remains unclear. The aim of this preliminary study was to investigate the effect of inferior alveolar nerve (IAN) rupture on mandibular bone remodeling of patients underwent bilateral sagittal split ramus osteotomy (BSSRO).Ten patients with unilateral IAN rupture during BSSRO were involved in this study. Neurosensory examinations were employed to assess the sensory function of bilateral IAN. The remodeling process of the post-operational mandible was evaluated by panoramic radiographs and computed tomography (CT) scans.Neurosensory examinations indicated that nerve rupture resulted in significant hypoesthesia at the IAN-rupture side. Assessment of panoramic radiographs showed no evident alterations of bone structure at the IAN-rupture side of mandible. Evaluation of CT images also indicated no statistical difference in bone density and thickness between IAN-rupture side and contralateral side.Accordingly, our study indicated that IAN rupture may not significantly impair the short-term bone remodeling process of human mandible.

Modified Mandibular Sagittal Split Osteotomy.

Mandibular osteotomies aim to displace the dental arch to the necessary position, ideally without limitation, while preserving inferior alveolar nerve (IAN) function. Supraforaminal osteotomies offer nerve safety but limit the extent of advancement, whereas Epker and Obwegeser-Dal Pont osteotomies enable unchallenged mandibular advancement but are associated with an inferior border notch. Here, we describe a new technique to avoid such disadvantages. The beginning of the procedure was similar to Epker's technique, with sectioning of the lingual cortex up to the level of the lingula. Sectioning of the buccal cortex was stopped 3 to 4 mm above the inferior border and then performed horizontally up to the gonial angle in total thickness. The inferior border periosteum and muscles attachments were conserved and hence, appropriately vascularized. This technique offers 4 advantages: absence of the inferior border notch, lower risk of damage to the IAN than with Epker's technique, sufficiently large bony surface to obtain bone healing as in Epker's technique, and no limitation to setback movement in contrast to Obwegeser-Dal Pont's or the supraforaminal osteotomy techniques.

Management of Mandibular Osteomyelitis With Segmental Resection, Nerve Preservation, and Immediate Reconstruction

The purpose was to present our experience with management of mandibular osteomyelitis with segmental resection, nerve preservation, and immediate reconstruction with nonvascularized bone grafts. We completed a retrospective analysis of 18 cases overseen by a single practitioner at a university medical center from June 2011 to July 2018. All patients had osteomyelitis and were treated with segmental mandibular resection, inferior alveolar nerve (IAN) preservation, and immediate reconstruction with autogenous bone graft from the tibia. Data obtained from medical records included the chief complaint at initial presentation, resection size, and IAN neurosensory recovery at 6months, as well as descriptive statistics of the patient cohort. The university institutional review board granted this study exempt status. The patient cohort had a mean age of 50.9years, ranging from 29 to 70years, and included 11 female and 7 male patients. The mean follow-up time was 15months. The most common chief complaint at initial presentation was pathologic fracture (39%), followed closely by abscess (33%). The average mandibular resection size of all patients was 8.1cm (standard deviation [SD], 3.3cm). The resection size measured 7.1cm (SD, 2.6cm) in patients with successful bone grafts (n=15) and 13.1cm (SD, 2.0cm, P=.0016) in those with graft failure (n=3). IAN neurosensory testing showed that 54% of patients had no meaningful recovery at 6months, 25% had partial recovery, and 21% had full recovery. Finally, osteomyelitis was eliminated in all patients. Segmental mandibular resection is an effective method for eradicating mandibular osteomyelitis. Furthermore, immediate reconstruction via nonvascularized grafts is successful in cases with large defects, with a mean defect size of 7.1±2.6cm. However, IAN-sparing surgery is not effective for preserving patient IAN function. Taken together, our findings show that mandibular resection with immediate reconstruction is a viable method in the treatment of mandibular osteomyelitis. This method removes infection and shortens the disease course.

Relationship of distraction rate with inferior alveolar nerve degeneration-regeneration shift.

Distraction osteogenesis is an important technique for the treatment of maxillofacial abnormities and defects. However, distraction osteogenesis may cause the injury of the inferior alveolar nerve. The relationship between distraction rate and nerve degeneration-regeneration shift remains poorly understood. In this study, 24 rabbits were randomly divided into four groups. To establish the rabbit mandibular distraction osteogenesis model, the mandibles of rabbits in distraction osteogenesis groups were subjected to continuous osteogenesis distraction at a rate of 1.0, 1.5 and 2.0 mm/d, respectively, by controlling rounds of screwing each day in the distractors. In the sham group, mandible osteotomy was performed without distraction. Pin-prick test with a 10 g blunt pin on the labium, histological and histomorphometric analyses with methylene blue staining, Bodian's silver staining, transmission electron microscopy and myelinated fiber density of inferior alveolar nerve cross-sections were performed to assess inferior alveolar nerve conditions. At 28 days after model establishment, in the pin-prick test, the inferior alveolar nerve showed no response in the labium to a pin pricks in the 2 mm/d group, indicating a severe dysfunction. Histological and histomorphometric analyses indicated that the inferior alveolar nerve suffered more degeneration and injuries at a high distraction rate (2 mm/d). Importantly, the nerve regeneration, indicated by newborn Schwann cells and axons, was more abundant in 1.0 and 1.5 mm/d groups than in 2.0 mm/d group. We concluded that the distraction rate was strongly associated with the inferior alveolar nerve function, and the distraction rates of 1.0 and 1.5 mm/d had regenerative effects on the inferior alveolar nerve. This study provides an experimental basis for the relationship between distraction rate and nerve degeneration-regeneration shift during distraction osteogenesis, and may facilitate reducing nerve complications during distraction osteogenesis.

Incidence of inferior alveolar nerve affection with and without nerve exposure during bilateral sagittal split osteotomy

Objective: The aim of this study was to determine the presence and severity of inferior alveolar nerve (IAN) affection during bilateral sagittal split osteotomy (BSSO) in two groups of patients with and without direct exposure and visualization of the nerve during surgical procedure.Patients and Methods: In this prospective randomized clinical study, 14 patients (28 sides) indicated for BSSO were included. The sides were randomly divided into two groups with equal number of sides (14 sides). Group I with wide soft tissue dissection of the medial side of the ramus and exposure of IAN above the ligula and group II with minimal soft tissue dissection of the medial side of the ramus without exposure of IAN. For evaluation of neurosensory function of IAN, two methods were used including subjective evaluation and two-point discrimination test.Results: According to the subjective evaluation, there was a statistically significant difference between both groups in favor of group II in all follow-up recalls except in the final one at 12 months postoperatively. Considering the results of two-point discrimination test, the improvement obviously continued during the successive follow-up periods in both groups, with a statistically significant difference in favor of group II until the ninth month, and then in the last follow-up at the 12th month, the records were almost equal.Conclusion: To markedly reduce the postoperative neurosensory disturbances of IAV and to accelerate the full recovery of sensation of the lower lip and chin regions following BSSO, limited exposure and dissection of the medial soft tissues of the ramus should be practiced with avoidance of direct exposure and manipulation of IAN.

Neurosensory evaluation of inferior alveolar nerve after bilateral sagittal split ramus osteotomy of mandible

Mandibular skeletal deformities are mostly corrected by Sagittal Split Ramus Osteotomy. One of the main complications of Bilateral Sagittal Split Ramus Osteotomy is impairement of sensory function of Inferior Alveolar Nerve. ObjectivesTo evaluate the occurrence of neurosensory disturbance by comparing the subjective and objective assessment of neurosensory responses after bilateral sagittal split ramus osteotomy.To assess the progress of recovery from the first post operative day till six months. To explain the factors causing neurosensory disturbances. MethodA series of 24 patients with clinically and radiographically diagnosed mandibular skeletal deformity were treated with Bilateral Sagittal Split Ramus Osteotomy. For evaluation of the neurosensory responses, the parameters consist of subjective and objective test in order to compare the subjective and objective assessment. ResultsOn the first post operative day neurosensory disturbances were seen in all the patients. Recovery of sensation was seen in all the patients at the end of this study. ConclusionThe incidence of functional nerve disturbances is acceptable, since the progression towards recovery is inevitable. Prolonged neurosensory disturbance is greatly related to the degree of manipulation of the inferior alveolar nerve.

Subjective and qualitative assessment of neural disturbance after inferior alveolar nerve transposition for dental implant placement.

BackgroundThe purpose of this retrospective study was to accumulate data regarding the quality of postoperative neurosensory function after inferior alveolar nerve (IAN) transposition for dental implant placement.MethodsThe study included seven consecutive patients who underwent IAN transposition surgery for the insertion of a dental implant into the atrophic posterior mandible. Of these, six patients (seven sides) were available for long-term assessment of postoperative IAN function. Neurosensory disturbance of the IAN was assessed objectively using the modified SW perception test reported by Semmes and Weinstein. In addition, the quality of nerve paralysis was assessed according to the criteria reported by Highet.ResultsThe median follow-up time was 49 months (range 12–105 months). No implant loss was observed during the follow-up. All patients experienced numbness immediately and the days after surgery. Complete recovery of neural function was observed on two sides; weak hypoesthesia was observed on two sides, moderate hypoesthesia on two sides, and severe hypoesthesia on one side. However, only one patient expressed concern about IAN function.ConclusionsIAN transposition is a useful method for placing implants in the atrophic posterior mandible. However, the procedure is complicated, with the possibility of some degree of neurosensory disturbance, although in most of our cases, it resolved within a clinically acceptable period.

The use of piezoelectric surgery to lateralize the inferior alveolar nerve with simultaneous implant placement and immediate buccal cortical bone repositioning: a prospective clinical study

A prospective study was conducted to assess a variation of inferior alveolar nerve (IAN) lateralization. This study included 13 patients. An osteotomy was made with a piezoelectric device, and the IAN bundle was moved buccally. Dental implants were then inserted medial to the nerve bundle, and the inner surface of the buccal cortical bone plate was shaped to reduce its thickness. Finally, the bone plate was repositioned to restore the original shape and contour of the mandible. Neurosensory examinations of the lower lip and chin were performed using three tests: light touch, pain, and two-point discrimination. Three months after surgery, the function of the IAN was judged to be completely restored at 11 of the 13 surgical sites. Differences in the tests comparing the operated and non-operated sides were not significant. No implants were lost, and all patients were satisfied with the result. Although IAN lateralization in conjunction with dental implant placement is rarely indicated, the use of a piezoelectric device to perform a buccal osteotomy with final repositioning of the buccal cortical plate over the bony defect contributes to the recovery of the contour and shape of the mandible, without impairment of IAN function.

Neurosensory disturbance after bilateral sagittal split osteotomy: A retrospective study

AimTo retrospectively evaluate neurosensory disturbance (NSD) after bilateral sagittal split osteotomy (BSSO). Material and methodsA retrospective review was carried out to assess inferior alveolar nerve function in patients treated by BSSO from 2010 to 2013. All patients included in the study were assessed using objective (cotton swabs and pin prick testing) and subjective testing (questionnaire) for inferior alveolar nerve function after a minimum of 1 year of follow-up. Medical records of the patients were used to assess the incidence of NSD in the immediate post-operative period. Results15 patients (30 sides) had undergone BSSO during the specified time period. On subjective testing, NSD was reported in 22 operated sides (73.3%) in the immediate post-operative period, while 4 operated sides (13.3%) reported persistent NSD. On objective testing, immediate post-operative NSD was seen in 20 operated sides (66.7%). After a minimum of 1 year follow-up, recovery was seen in 18 operated sides while persistent NSD was seen in 2 operated sides (6.7%). ConclusionNSD of the inferior alveolar nerve is a common complication after BSSO in the immediate post-operative period. However in a long term, nerve function usually recovers.

Inferior alveolar nerve function recovers after decompression of large mandibular cystic lesions.

The treatment of large mandibular cystic lesions (diameter>35mm) is controversial. Few studies determine the inferior alveolar nerve function after decompression which is one of the major options for treating such lesions. We aim to investigate the recovery of inferior alveolar nerve function after decompression. Twenty-two patients with large mandibular cystic lesions, diagnosed as keratocystic odontogenic tumor, ameloblastoma, or dentigerous cyst, were included. Inferior alveolar nerve function was observed by monitoring the pulp vitality of involved teeth (n=64) with electric pulp test before decompression and 1, 3, 6, 9, 12, and 24months after decompression, respectively. The pulp vitality of the involved teeth was significantly decreased before decompression. Recovery of pulp vitality could be observed after decompression, indicating the recovery of inferior alveolar nerve function. A majority (96.9%) of the vital pulp was preserved in the involved teeth after decompression. Recovery of inferior alveolar nerve function was remarkable in patients with large mandibular cystic lesions after decompression, indicated by the recovery of pulp vitality of involved teeth. When decompression is preferred, conservative therapy rather than root canal therapy is recommended for the teeth with root tip exposed in the cystic lesions and without pulposis.

Inferior Alveolar Nerve Function After Sagittal Split Osteotomy by Reciprocating Saw or Piezosurgery Instrument: Prospective Double-Blinded Study

The aim of this prospective study was to objectively evaluate inferior alveolar nerve (IAN) sensory disturbances in patients who underwent sagittal split ramus osteotomy (SSRO) by comparing 1 side treated with a reciprocating saw with the other side treated with a piezosurgery device. Clinical evaluation of IAN sensory disturbance was undertaken preoperatively and at 1 week, 4 weeks, 2 months, and 6 months postoperatively in 20 patients who underwent SSRO at the Division of Oral and Maxillofacial Surgery, Araraquara Dental School, São Paulo State University. The 20 patients were examined at all periods for IAN functionality by Semmes-Weinstein testing; neither the patients nor the examiner knew which side was treated using piezosurgery or a reciprocating saw. The mean age of the patients was 28.4 years (range, 20 to 48 yr). Before surgery, no patient had impaired function of the IAN in any of the 8 zones in the mental and inferior lip areas. All patients reported feeling the first monofilament at the time of the preoperative test. Seven days postoperatively, all patients reported some kind of altered sensitivity in at least 1 zone evaluated. The results of this study suggest there was no statistically significant difference in the sensitivity of the labiomental area regarding the instrument used to perform the osteotomy. Future studies will focus on enlarging the sample and evaluating the results.

Electrophysiologic Evaluation of Inferior Alveolar Nerve Regenerated by Bifocal Distraction Osteogenesis in Dogs

Bifocal distraction osteogenesis has been shown to be a reliable method for reconstructing missing bone segments. However, there are no reports regarding inferior alveolar nerve regeneration during bifocal distraction. In the present study, the authors evaluated the function of inferior alveolar nerve regenerated by bifocal distraction after segmental resection in the mandibles of dogs. Using a bifocal distraction osteogenesis method, the authors produced a 10-mm mandibular defect and distracted the transport disk at a rate of 1 mm/day. The regenerated inferior alveolar nerve was evaluated by electrophysiologic analysis that was performed on all dogs after euthanasia at 3, 6, and 12 months after the first operation. At 6 and 12 months, stable evoked potential measurements were obtained from the nerves throughout the study on electrophysiologic analyses. The authors' results indicate that the inferior alveolar nerve regenerated by bifocal distraction osteogenesis functioned electrophysiologically at 6 months after the first operation. Although our research is still at the stage of animal experiments, future application in humans is considered to be possible.