Sensory Rehabilitation after Trigeminal Nerve Injury or Nerve Repair

Diagnosis and Management of Lingual Nerve Injuries

Injury to the lingual nerve is a well-recognized risk associated with certain routine dental and oral surgical procedures. The assessment and management of a patient with a traumatic lingual nerve neuropathy requires a logical and stepwise approach. The proper application and interpretation of the various neurosensory tests and maneuvers is critical to establishing an accurate diagnosis. The implementation of a surgical or nonsurgical treatment strategy is based not only on the established diagnosis, but also a multitude of variables including patient age, timing and nature of the injury, and the emotional or psychological impact.

Outcomes of Direct Lingual Nerve Repair After an Injury: A Systematic Review

PURPOSE

The purpose of this study was to conduct a systematic review with meta-analysis to investigate the outcomes of direct lingual nerve repair after injury.

MATERIALS AND METHODS

The studies in this review were compiled by using PubMed/Medline and ScienceDirect, which were searched by a single reviewer (M.K.) from their inception until March 10, 2020. Two independent reviewers (M.K. and V.B.Z.) who were blinded to each other's assessments reviewed full-text articles to assess for study inclusion. Outcomes were dichotomized as either functional sensory recovery (FSR) or no FSR. Clinical testing must have been assessed at a minimum of 6 months postoperatively. FSR was defined as grade S3, S3⁺, or S4 on the British Medical Research Council scale of neurosensory function. Studies were only eligible if they provided the number of patients treated with conduits or time from injury to repair and the associated rates of FSR with each intervention.

RESULTS

The initial search using the key terms yielded 4,921 results, which was then eventually filtered down to 6 articles after multiple levels of appraisal. Five articles were retrospective cohort studies and 1 was a randomized controlled study. Four of the 6 studies reported an FSR of grade S3 or higher in 85% or more of the patients. Conduit use was not associated with a significantly greater likelihood of achieving FSR (pooled risk ratio = 1.10; 95% confidence interval, 0.96 to 1.27; P = .17). Repair within 6 months was associated with significantly improved likelihood of achieving FSR (pooled risk ratio = 0.84; 95% confidence interval, 0.71 to 0.99; P = .04).

CONCLUSIONS

The use of conduits during repair was not associated with clinically significant increased FSR. Early repair was associated with a beneficial effect on FSR; however, heterogeneity was an issue with the studies. There is a lack of strong evidence owing to the nature of studies analyzed and the need for further research is required.

Use of Fibrin Glue as an Adjunct in the Repair of Lingual Nerve Injury: Case Report

This report describes a case of lingual nerve injury repair using a novel technique in which Tisseel fibrin glue was used to stabilize an Axoguard nerve conduit placed around the site of primary neurorrhaphy to decrease the number of sutures required for stabilization. Five months postoperatively, the patient subjectively had increased sensation and improved taste in the left lingual nerve distribution. At neurosensory examination, the patient exhibited functional neurosensory recovery (S3+ on the Medical Research Council Scale).

Interventions for iatrogenic inferior alveolar and lingual nerve injury

BACKGROUND

Iatrogenic injury of the inferior alveolar or lingual nerve or both is a known complication of oral and maxillofacial surgery procedures. Injury to these two branches of the mandibular division of the trigeminal nerve may result in altered sensation associated with the ipsilateral lower lip or tongue or both and may include anaesthesia, paraesthesia, dysaesthesia, hyperalgesia, allodynia, hypoaesthesia and hyperaesthesia. Injury to the lingual nerve may also affect taste perception on the affected side of the tongue. The vast majority (approximately 90%) of these injuries are temporary in nature and resolve within eight weeks. However, if the injury persists beyond six months it is deemed to be permanent. Surgical, medical and psychological techniques have been used as a treatment for such injuries, though at present there is no consensus on the preferred intervention, or the timing of the intervention.

OBJECTIVES

To evaluate the effects of different interventions and timings of interventions to treat iatrogenic injury of the inferior alveolar or lingual nerves.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Oral Health Group's Trial Register (to 9 October 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 9), MEDLINE via OVID (1946 to 9 October 2013) and EMBASE via OVID (1980 to 9 October 2013). No language restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving interventions to treat patients with neurosensory defect of the inferior alveolar or lingual nerve or both as a sequela of iatrogenic injury.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by The Cochrane Collaboration. We performed data extraction and assessment of the risk of bias independently and in duplicate. We contacted authors to clarify the inclusion criteria of the studies.

MAIN RESULTS

Two studies assessed as at high risk of bias, reporting data from 26 analysed participants were included in this review. The age range of participants was from 17 to 55 years. Both trials investigated the effectiveness of low-level laser treatment compared to placebo laser therapy on inferior alveolar sensory deficit as a result of iatrogenic injury.Patient-reported altered sensation was partially reported in one study and fully reported in another. Following treatment with laser therapy, there was some evidence of an improvement in the subjective assessment of neurosensory deficit in the lip and chin areas compared to placebo, though the estimates were imprecise: a difference in mean change in neurosensory deficit of the chin of 8.40 cm (95% confidence interval (CI) 3.67 to 13.13) and a difference in mean change in neurosensory deficit of the lip of 21.79 cm (95% CI 5.29 to 38.29). The overall quality of the evidence for this outcome was very low; the outcome data were fully reported in one small study of 13 patients, with differential drop-out in the control group, and patients suffered only partial loss of sensation. No studies reported on the effects of the intervention on the remaining primary outcomes of pain, difficulty eating or speaking or taste. No studies reported on quality of life or adverse events.The overall quality of the evidence was very low as a result of limitations in the conduct and reporting of the studies, indirectness of the evidence and the imprecision of the results.

AUTHORS' CONCLUSIONS

There is clearly a need for randomised controlled clinical trials to investigate the effectiveness of surgical, medical and psychological interventions for iatrogenic inferior alveolar and lingual nerve injuries. Primary outcomes of this research should include: patient-focused morbidity measures including altered sensation and pain, pain, quantitative sensory testing and the effects of delayed treatment.

Sensory retraining: a cognitive behavioral therapy for altered sensation

Sensory retraining teaches the patient to ignore or blot out postinjury unpleasant orofacial sensations to optimally tune into and decipher the weakened and damaged signals from the tissues. Sensory retraining is a simple, inexpensive, noninvasive exercise program, which initiated shortly after injury, can lessen the objectionable impression of orofacial altered sensations. Sensory retraining exercises are most effective on decreasing the perceived burden associated with hypoesthetic orofacial altered sensations.

Management of mandibular nerve injuries from dental implants

Treatment of the patient who has sustained a nerve injury from dental implant procedures involves prompt recognition of this complication, evaluation of sensory dysfunction, the position of the nerve vis-à-vis the implant, and timely management of the injured nerve. In some patients, removal or repositioning of the implant and surgical exploration and repair of the injured nerve will maximize the implant patient's potential for a successful recovery from nerve injury.

Nerve injuries from mandibular third molar removal

Injuries to peripheral branches (IAN, LN, LBN) of the trigeminal nerve during the removal of M3s are known and accepted risks in oral and maxillofacial surgery practice. These risks might be reduced by modifications of evaluation or surgical techniques, depending on the surgeon's judgment in individual patients. If a nerve injury does occur, prompt recognition, subjective and objective evaluation,and development of a treatment plan, if the sensory deficit fails to resolve in a reasonable period and is unacceptable to the patient, give the patient the best chance of achieving improvement or recovery of sensory function in the distribution of the injured nerve. Microneurosurgery may produce return of useful sensory function or complete sensory recovery, if done in a timely fashion by an experienced microsurgeon, in greater than 80% of patients who sustain nerve injuries during the removal of M3s.

Sensory retraining after orthognathic surgery: effect on patients' perception of altered sensation

PURPOSE

The primary research hypothesis was that the magnitude and duration of the perceived burden from altered sensation reported by patients after bilateral sagittal split osteotomy and trauma to the third division of the trigeminal nerve are decreased when facial sensory retraining exercises are performed in conjunction with standard opening exercises as compared with standard opening exercises alone.

SUBJECTS AND METHODS

A total of 186 subjects were enrolled in a multicenter, double-blind, 2 parallel group-stratified block randomized clinical trial. Oral and facial pain, unusual sensations, numbness, and loss of sensitivity were scored from "no problem" to "serious problem" before surgery and 1 month, 3 months, and 6 months after surgery. A proportional odds model for the ordered multinomial response was used to compare the responses of the 2 exercise groups.

RESULTS

The 2 exercise groups did not differ significantly at any postsurgical time in terms of perceived problem level from intraoral of facial pain. The difference between the 2 groups at each visit was not statistically significant for unusual sensations, although the trend was for the sensory retraining group to have a higher likelihood of reporting fewer problems. By 6 months, the likelihood of a subject reporting lower problem or interference level related to numbness or decreased lip sensitivity was significantly higher in the sensory-retraining group, approximately twice that of the opening exercise-only group.

CONCLUSIONS

Our results support the premise that a simple noninvasive exercise program initiated shortly after orthognathic surgery can lessen the objectionable impression of negative altered sensations.

Effect of distraction osteogenesis on the severely hypoplastic mandible and inferior alveolar nerve function

PURPOSE

The purpose of this study was to examine the effect of distraction osteogenesis surgery on the inferior alveolar nerve (IAN) and on the stability of the occlusion in patients undergoing mandibular osteotomy and advancement for correction of severe retrognathia.

MATERIALS AND METHODS

Five patients (4 women and 1 man) underwent vertical posterior body osteotomy or bilateral sagittal split ramus osteotomy with the application of a distraction device for advancement of the mandible of 10 to 14 mm. After a period of latency, each mandible was advanced 1 mm per day until the patient achieved a Class I occlusion. Distraction devices were removed after a suitable period of consolidation (4 to 11 months). IAN sensory function was evaluated by 2-point discrimination, response to painful stimulus, and moving brush stroke identification. Testing of the IAN was performed on all patients at 7 different time intervals: preoperative (T0), postsurgery and predistraction (T1), within 7 days after the end of distraction (T2), 3 months after T2 (T3), 6 months after T2 (T4), 9 months after T2 (T5), and 1 year after T2 (T6). The same surgeon performed all IAN testing.

RESULTS

There were no instances of malunion or fibrous union. At the 1-year follow-up, all 5 patients showed no relapse of their advancement as assessed by their maintenance of a Class I occlusion. Radiographic analysis was not done to discern skeletal versus dental stability. All 10 IANs were intact after the initial surgery. As time progressed, all 10 nerves showed improvement of function as measured by 2-point discrimination, response to painful stimulus, and moving brush stroke identification. At 1 year postsurgery, all 10 nerves showed function consistent with or very near presurgery levels.

CONCLUSION

Stable mandibular advancements of 10 mm and greater can be successfully accomplished by distraction osteogenesis without producing significant damage to the IAN.