Inferior alveolar nerve transposition in conjunction with implant placement

PURPOSE: The aim of this prospective study was to determine the incidence of neurosensory disturbance and the cumulative survival and success rates of ITI solid-screw implants placed in conjunction with an inferior alveolar nerve (IAN) transposition technique. MATERIALS AND METHODS: 46 ITI implants were placed in 15 patients following transposition of the IAN. In 4 patients nerve transpositioning was performed bilaterally, so a total of 19 IAN mobilization surgeries were performed. Neurosensory dysfunction was objectively evaluated by using light touch (LT), pain (PT), and 2-point discrimination (2-DT) tests. In addition, patients were asked to answer a short questionnaire to investigate individual feelings of discomfort and advantages related to this surgical technique. The mean follow-up period was 49.1 months (range, 12 to 78 months). RESULTS: The cumulative implant survival and success rates were 95.7% and 90.5%, respectively. Only 2 implants were lost. Neurosensory disturbance (ie, disturbance registered by the LT, PT, and 2-DT tests) was experienced in 4 of 19 cases. However, at the time of data analysis (12 to 78 months after surgery), all patients indicated that they would go through the surgery again. DISCUSSION: The IAN transposition technique, when used in the severely atrophied posterior mandible, allowed placement of implants with adequate length and good initial stabilization. All patients felt that they had received significant benefits from their new prostheses. CONCLUSION: Based on the results of the present study, it can be concluded that lateral nerve transposition can be used as a surgical procedure to enable ITI implant placement in the severely resorbed posterior mandible.     

Inferior alveolar nerve lateral transposition

Purpose

We determined the outcomes of 18 inferior alveolar nerve lateral transposition procedures in 15 consecutive patients. The advantages and disadvantages of this technique are discussed.

Results

The surgical protocol for inferior alveolar nerve transposition, followed by implant placement, presented excellent results, with complete recovery of the sensitivity within 6 months after the surgical procedure.

Discussion

Inferior alveolar nerve transposition is an option for prosthetic rehabilitation in cases of moderate or even severe bone reabsorption for patients that do not tolerate removable dentures.

Conclusions

It is concluded that inferior alveolar nerve transposition can be safely and predictably performed with low risk to the mental nerve sensibility. Each patient should be advised of the chance of permanent nerve deficit throughout the distribution of the mental nerve. Alternative restorative solutions should also be considered.     

Inferior alveolar nerve transposition in combination with Br?nemark implant treatment.

The surgical protocol for inferior alveolar nerve transposition together with the Br?nemark implant treatment is described. The short-term follow-up results of the first ten procedures are presented and show an initial 2- to 3-week duration of anesthesia. In all regions treated, signs of paresthesia/hypoesthesia have been registered for 1 to 7 months. After 6 months, seven of the regions recovered completely with regard to nerve sensation.     

Inferior alveolar nerve lateralization and implant placement in atrophic posterior mandible

The aims of this article were to describe the surgical technique of the inferior alveolar nerve lateralization followed by implant installation by means of a clinical report and also to discuss the importance of an adequate surgical and prosthetic planning for atrophic posterior mandible rehabilitation.     

Fixture placement posterior to the mental foramen with transpositioning of the inferior alveolar nerve.

The results of 10 fixture placement operations with transpositioning of the inferior alveolar nerve are presented. Nerve transpositioning increased the operating time, but with experience this time should be reduced. Neurosensory dysfunction of the inferior alveolar nerve was found in 7 of 10 operated sites 1 week after surgery. Six months postoperatively, altered sensation was still present in 2 patients. Nerve function was normal in all patients 1 year postoperatively. The stability of fixtures was satisfactory throughout the examination period and the procedure should prove useful in treatment of the resorbed mandible posterior to the mental foramina.     

Inferior alveolar nerve transposition and reposition for dental implant placement in edentulous or partially edentulous mandibles: a multicenter retrospective study

The aim of this study was to evaluate the success and complications following inferior alveolar nerve (IAN) transposition/reposition for dental implant placement in edentulous or partially edentulous mandibles. This was a multicenter retrospective study; patients who had undergone IAN transposition/reposition at four surgical clinics were retrospectively evaluated. Adverse effects, especially neural disturbances, were recorded and followed. Overall, 68 IAN reposition and 11 nerve transposition procedures were performed in 57 patients (only three patients reported on smoking). The residual bone above the IAN was an average 3.88 ± 1.98 mm. A total of 232 dental implants were inserted in the area after transposition/reposition of the nerve. The average follow-up time was 20.62 ± 9.79 months, ranging from 12 to 45 months. One implant loss was observed during the follow-up period. Four patients reported prolonged transient neural disturbances immediately following surgery (5% of the operations). The duration of neural disturbances after the surgery ranged from 1 to 6 months. No permanent neural damage was reported. Thus, within this study's limitations, it can be concluded that IAN transposition and reposition are useful adjunct techniques for managing severely atrophic edentulous or partially edentulous mandibles with dental implants. The risk of neural dysfunction appears to be low.     

Inferior alveolar nerve repositioning in implant surgery

Severe resorption of the posterior mandible possesses one of the most difficult restorative challenges to the implant surgery today. This resorption may prevent the placement of dental implants without the potentially damage to the inferior alveolar nerve. To create the opportunity of insertion dental implants of adequately length in those cases, the technique of nerve repositioning has been advocated. The purpose of this article is to describe two cases of nerve repositioning combined with placement of dental implants. Both cases showed appropriate postoperative healing without damage to the inferior alveolar nerve. The inferior alveolar nerve repositioning technique seems to be an acceptable alternative to augmentation procedure prior to dental implants placement in cases exhibiting atrophic posterior mandibular ridges.     

Endosseous implant placement in conjunction with inferior alveolar nerve transposition: a report of an unusual complication and surgical management

Inferior alveolar nerve transposition and placement of endosseous implants is one of the treatment options for patients with an edentulous posterior mandible with inadequate bone height superior to the inferior alveolar canal. The possible complications associated with this technique include prolonged neurosensory disturbances, infection, and pathologic fracture. This report presents the surgical management of a patient who sustained a mandibular fracture after inferior alveolar nerve transposition for the placement of 3 endosseous implants.     

Inferior alveolar nerve repositioning

Nerve repositioning is a viable alternative for patients with an atrophic edentulous posterior mandible. Patients, however, should be informed of the potential risks of neurosensory disturbance. Documentation of the patient's baseline neurosensory function should be performed with a two-point discrimination test or directional brush stroke test preoperatively and postoperatively. Recovery of nerve function should be expected in 3 to 6 months. The potential for mandibular fracture when combining nerve repositioning with implant placement also should be discussed with the patient. This can be avoided by minimizing the amount of buccal cortical plate removal during localization of the nerve and maintaining the integrity of the inferior cortex of the mandible. Additionally, avoid overseating the implant, thus avoiding stress along the inferior border of the mandible. The procedure does allow for the placement of longer implants, which should improve implant longevity. Patients undergoing this procedure have expressed overall satisfaction with the results. Nerve repositioning also can be used to preserve the inferior alveolar nerve during resection of benign tumors or cysts of the mandible. This procedure allows the surgeon to maintain nerve function in situations in which the nerve would otherwise have to be resected.     

Lateralization of the inferior alveolar nerve with simultaneous implant placement: a modified technique

PURPOSE: Several nerve repositioning techniques have ben presented in the literature, each with limitations. This article presents a new technique involving the use of 2 osteotomies, with minimizes particularly the potential duration of sensory disruption and the risk of nerve paresthesia and inadvertent nerve transection or compression. MATERIALS AND METHODS: Ten patients ranging in age from 47 to 67 years were selected for nerve lateralization utilizing the modified technique. A total of 23 cylindrical implants were placed. An average follow-up period was 29.8 months. RESULTS: Of the 10 patients, 4 experienced total return of sensation within 3 to 4 weeks. One patient experienced complete recovery at 6 weeks. DISCUSSION: Creating 2 osteotomies as described minimizes the chances for postoperative neuropraxia and nerve paresthesia or anesthesia. CONCLUSION: When there is moderate-to-severe bone resorption of the mandible posterior to the mental foramen, repositioning the inferior alveolar nerve using both an anterior and posterior osteotomy allows for more bone to accommodate ideal placement and greater length of implant.     

Risk assessment of inferior alveolar nerve injury for immediate implant placement in the posterior mandible: A virtual implant placement study

Objectives

To investigate the prevalence and morphological parameters of lingual concavity, and whether these factors are related to a higher risk of inferior alveolar nerve (IAN) injury when performing an immediate implant surgery in posterior mandible region.

Methods

The CBCT images from 237 subjects (1008 teeth) were analysed the shape of the mandibles (C, P, U type), dimensional parameters of lingual concavity (angle, height, depth), and its relation to inferior alveolar canal (IAC) (A, B, C zone), RAC (distance from root apex to IAC) and probability of IAN injury. Multiple logistic regression modelling to determine the odds ratio of variables that made an important contribution to the probability of IAN injury and to adjust for confounding variables.

Results

The U type ridge (46.7%) and the most concave point located at C zone (48.8%) are most prevalent in this region. The mandibular second molar presents highest risk for IAN injury than other tooth type (p < 0.001), which were 3.82 times to occur IAN injury than the mandibular second premolar. The concave point located at A zone and B zone were 7.82 and 3.52 times than C zone to have IAN damage, respectively. The probability of IAN injury will reduce 26% for every 1 mm increase in RAC (p < 0.001).

Conclusions

The tooth type, morphological features of lingual concavities, and RAC are associated with risks of IAN injury during immediate implant placement.

Clinical significance

Pre-surgical mapping of the IAC and identification of its proximity relative to the lingual concavity in the posterior mandible regions may avoid unpleasant complications, specifically when performing immediate implant procedures.     

Complications associated with inferior alveolar nerve repositioning for dental implant placement: a systematic review

Inferior alveolar nerve (IAN) repositioning has been used widely in recent years as an alternative approach for dental implant placement in the atrophic posterior mandible. The aim of this study was to answer the question: What are the complications associated with IAN repositioning? A systematic literature review performed in accordance with the PRISMA statement, using the PubMed (MEDLINE), Cochrane Library, and Scopus databases, identified a total of 116 articles related to this technique. Of those articles, 24 were included in the final review. Lateralization was the chosen technique in seven studies, transposition in 15 studies, and two studies reported both techniques. The longest follow-up period was 49.1 months and the shortest 6 months. Of the patients who underwent lateralization, 95.9% initially showed a neurosensory disturbance, and the condition remained at the end of the study for 3.4% of those patients. With regard to the patients who underwent transposition, neurosensory alterations were observed in 58.9% of patients initially, and the condition remained for 22.1% of those affected at the end of the study. Only one study found no neurosensory disturbance at any time. More data consolidation is necessary to determine scientifically if, which, and when the IAN repositioning technique can be recommended.     

Inferior alveolar nerve repositioning in conjunction with placement of osseointegrated implants: a case report

A procedure for relocation of the inferior alveolar nerve to facilitate placement of endosseous implants is described. The technique permits placement of implants in an atrophied mandibular alveolar ridge that lacks sufficient vertical height superior to the mandibular canal. Placement of a fixed prosthesis instead of a removable appliance is facilitated.     

The mental foramen and nerve: clinical and anatomical factors related to dental implant placement: a literature review

BACKGROUND: The mental foramen is a strategically important landmark during osteotomy procedures. Its location and the possibility that an anterior loop of the mental nerve may be present mesial to the mental foramen needs to be considered before implant surgery to avoid mental nerve injury. METHODS: Articles that addressed the position, number, and size of the mental foramen, mental nerve anatomy, and consequences of nerve damage were evaluated for information pertinent to clinicians performing implant dentistry. RESULTS: The mental foramen may be oval or round and is usually located apical to the second mandibular premolar or between apices of the premolars. However, its location can vary from the mandibular canine to the first molar. The foramen may not appear on conventional radiographs, and linear measurements need to be adjusted to account for radiographic distortion. Computerized tomography (CT) scans are more accurate for detecting the mental foramen than conventional radiographs. There are discrepancies between studies regarding the prevalence and length of the loop of the mental nerve mesial to the mental foramen. Furthermore, investigations that compared radiographic and cadaveric dissection data with respect to identifying the anterior loop reported that radiographic assessments result in a high percentage of false-positive and -negatives findings. Sensory dysfunction due to nerve damage in the foraminal area can occur if the inferior alveolar or mental nerve is damaged during preparation of an osteotomy. CONCLUSIONS: To avoid nerve injury during surgery in the foraminal area, guidelines were developed based on the literature with respect to verifying the position of the mental foramen and validating the presence of an anterior loop of the mental nerve. These guidelines included leaving a 2 mm zone of safety between an implant and the coronal aspect of the nerve; observation of the inferior alveolar nerve and mental foramen on panoramic and periapical films prior to implant placement; use of CT scans when these techniques do not provide clarity with respect to the position of the nerve; surgical corroboration of the mental foramen's position when an anterior loop of the mental foramen is suspected of being present or if it is unclear how much bone is present coronal to the foramen to establish a zone of safety (in millimeters) for implant placement; once a safety zone is identified, implants can be placed anterior to, posterior to, or above the mental foramen; and prior to placing an implant anterior to the mental foramen that is deeper than the safety zone, the foramen must be probed to exclude the possibility that an anterior loop is present. In general, altered lip sensations are preventable if the mental foramen is located and this knowledge is employed when performing surgical procedures in the foraminal area.     

MRI在下牙槽神经移位牙种植术前的临床应用

目的:利用先进的MRI方法显示IAN,用于IAN移位牙种植术前分析.方法:6例牙槽嵴严重萎缩患者,全景片、CT显示可用牙槽骨量严重不足,特别是IAN走行显示不清.MRI 3D MP-RAGE扫描,检查IAN走行和分支.结果:6例患者MRI图像清晰的显示出IAN的位置和分支及环状结构,准确测量牙槽嵴顶与IAN的距离.讨论:这种新的MRI方法清楚的显示IAN走行并且能够显示其环形结构.MRI图像也能够测量IAN与牙槽嵴顶之间距离.对于一些手术创伤感染导致全景片、CT显示下颌管不清的病例,MRI也能够显示其走行和环状结构.结论:MRI显示IAN用于牙种植术前设计,具有较良好的应用价值和CT无可比拟的临床特点.     

The incidence of altered sensation of the mental nerve after mandibular implant placement

PURPOSE: This study was designed to determine the incidence of altered sensation in patients undergoing mandibular endosseous implant placement. PATIENTS AND METHODS: Ninety-four consecutive patients who underwent the placement of mandibular implants constituted the study group. The only patients that were excluded from this study were those who had preexisting injury to the trigeminal nerve. Patients were followed using standard neurologic testing during the period immediately following implant placement through 6 months. Four hundred five implants were placed in 43 female and 51 male patients. Implant length selection was based on panoramic radiographs using known markers to correct for distortion. In 13 of the patients, the mandibular canal was not adequately visualized, and a computed tomography (CT) scan was used to plan the implant locations. Implants were selected to be located 2 mm above the inferior alveolar canal based on the panoramic images and 1 mm above the canal based on CT images. RESULTS: Eight patients reported altered nerve sensation at their first postimplant visit (8.5%). None of the patients experienced hyperesthesia or dysesthesia. Four of the eight patients with altered sensation had no objective findings or decreased nerve function. One of the patients remained totally anesthetic for 2 months, but reported return to normal function at 4 months. CONCLUSIONS: These findings indicate that a small percentage of patients experience altered sensation after the placement of mandibular endosseous implants. Unlike previous studies, no permanent altered sensation was found. By using proper treatment planning, one can offer endosseous implants with minimal risk of injury to the trigeminal nerve.