The nerves which supply sensation to the tongue, lower lip and chin can be injured during facial and mouth surgery, including surgery to remove lower wisdom teeth. 90% of these injuries are temporary, but if they last longer than 6 months then further treatment may be needed. Damage to these nerves can lead altered sensation, or even altered taste perception. There are many treatments available: surgical, laser treatment, drug treatments (antiepileptics, antidepressants, painkillers), and counselling. This research considers which one of these interventions is the most effective.
What was the research?
A systematic review of the evidence to find out which treatment for accidental damage to the lingual and alveolar nerves is most effective.
Who conducted the research?
The research was conducted by a team led by Paul Coulthard from the University of Manchester, on behalf of the Cochrane Oral Health Group. Evgeny Kushnerev, Julian M. Yates, Tanya Walsh, Neil Patel, Edmund Bailey and Tara F. Renton were also on the team.
What evidence was included in the review?
Data was extracted from two randomised controlled trials. A total of 31 people participated in the trials, and were randomly assigned to low level laser therapy or placebo. There were no trials on any of the other treatments.
What did the evidence say?
There was some evidence of an improvement with low level laser therapy when participants reported whether or not sensation was better in the lip and chin area. No studies reported on the effects of treatment on other outcomes such as pain, difficulty in eating or speaking or taste perception. No studies reported on quality of life or possible harms from the treatment.
How good was the evidence?
The overall quality of the evidence is very low as a result of limitations in the conduct and reporting of the two included studies, and the low number of participants.
What are the implications for dentists and the general public?
There is a lack of evidence to support or refute the effects of surgical, medical and psychological treatments for these types of injury, and very low quality evidence to support the effects of laser therapy on the condition. All front-line healthcare staff should be educated and trained in this area to increase and improve awareness, and to recognise and provide support for people with these injuries.
What should researchers look at in the future?
There is a need for randomized controlled trials to investigate the effectiveness of treatments for injuries to the nerves in the face and mouth. These trials should be conducted in specialist centres, with large numbers of patients presenting with the injuries. Researchers should look at altered sensation, pain and the effects of delayed treatment, amongst other issues. Improved partnership between general practitioners and specialist healthcare organizatons may be the first crucial step in the development of such trials.
Coulthard P, Kushnerev E, Yates JM, Walsh T, Patel N, Bailey E, Renton TF. Interventions for iatrogenic inferior alveolar and lingual nerve injury. Cochrane Database of Systematic Reviews 2014, Issue 4. Art. No.: CD005293. DOI:10.1002/14651858.CD005293.pub2.