Is Botulinum Toxin Effective in Treating Orofacial Neuropathic Pain Disorders? A Systematic Review.

BACKGROUND: The aim of this paper is to provide a systematic review of the literature regarding the clinical use of botulinum toxin (BTX) to treat various orofacial neuropathic pain disorders (NP). METHODS: A comprehensive literature search was conducted using Medline, Web of Science, and the Cochrane Library databases. Only randomized clinical trials (RCT) published between 2003 and the end of June 2023, investigating the use of BTX to treat NP, were selected. PICO guidelines were used to select and tabulate the articles. RESULTS: A total of 6 RCTs were selected. Five articles used BTX injections to treat classical trigeminal neuralgia, and one to treat post-herpetic neuralgia. A total of 795 patients received BTX injections. The selected studies utilised different doses and methods of injections and doses. All the selected studies concluded superiority of BTX injections over placebo for reducing pain levels, and 5 out 6 of them highlighted an improvement in the patient's quality of life. Most of the studies reported transient and mild side effects. CONCLUSION: There is evidence of the efficacy of BTX injections in orofacial pain management. However, improved study protocols are required to provide direction for the clinical use of BTX to treat various orofacial neuropathic pain disorders.

Botulinum Toxin for Treating Temporomandibular Disorders: What is the Evidence?

AIMS: To systematically review the scientific literature for evidence concerning the clinical use of botulinum toxin (BTX) for the management of various temporomandibular disorders (TMDs). METHODS: A comprehensive literature search was conducted in the Medline, Web of Science, and Cochrane Library databases to find randomized clinical trials (RCT) published between 2000 and the end of April 2021 investigating the use of BTX to treat TMDs. The selected articles were reviewed and tabulated according to the PICO (patients/problem/population, intervention, comparison, outcome) format. RESULTS: A total of 24 RCTs were selected. Nine articles used BTX injections to treat myofascial pain, 4 to treat temporomandibular joint (TMJ) articular TMDs, 8 for the management of bruxism, and 3 to treat masseter hypertrophy. A total of 411 patients were treated by injection of BTX. Wide variability was found in the methods of injection and in the doses injected. Many trials concluded superiority of BTX injections over placebo for reducing TMD pain levels and improving maximum mouth opening; however, this was not universal. CONCLUSION: There is good scientific evidence to support the use of BTX injections for treatment of masseter hypertrophy and equivocal evidence for myogenous TMDs, but very little for TMJ articular disorders. Studies with improved methodologic design are needed to gain better insight into the utility and effectiveness of BTX injections for treating both myogenous and TMJ articular TMDs and to establish suitable protocols for treating different TMDs.

Leprosy presenting as orofacial pain: case report.

This article reports an unusual case of neuropathic orofacial pain secondary to leprosy. To the authors' knowledge, it is the first case of leprosy reported in the Western literature that was initially thought to be dental pain, then mistaken as a temporomandibular disorder before the correct diagnosis was made. The patient had migrated to Australia from India 24 years previously and was otherwise healthy without any overt features suggestive of infection. A review of the literature revealed that the trigeminal nerve is frequently involved in leprosy, usually associated with sensory loss rather than neuropathic pain. Even in Western countries, patients originally from countries where leprosy is endemic may develop symptoms of the disease many years later. The possibility of leprosy should be considered in the diagnosis of neuropathic orofacial pain in such patients.

Trigeminal autonomic cephalalgias: a review and implications for dentistry.

BACKGROUND: The authors review the epidemiology, clinical features, pathophysiology, diagnosis, treatment, orofacial presentations and dental implications of trigeminal autonomic cephalalgias (TACs): cluster headache (CH), paroxysmal hemicrania (PH) and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT). TYPES OF STUDIES REVIEWED: The authors conducted PUBMED searches for the period from 1968 through 2007 using the terms "trigeminal autonomic cephalalgias," "cluster headache," "paroxysmal hemicrania," "short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing," "epidemiology," "pathophysiology," "treatment," "oral," "facial" and "dentistry." They gave preference to articles reporting randomized, controlled trials and those published in English-language peer-reviewed journals. RESULTS: TACs refers to a group of headaches characterized by unilateral head pain, facial pain or both with accompanying autonomic features. Although their pathophysiologies are unclear, CH, PH and SUNCT may be differentiated according to their clinical characteristics. Current treatments for each of the TACs are useful in alleviating the pain, with few refractory cases requiring surgical intervention. Patients with TACs often visit dental offices seeking relief for their pain. CLINICAL IMPLICATIONS: Although the prevalence of TACs is small, it is important for dentists to recognize the disorder and refer patients to a neurologist. This will avoid the pitfall of administering unnecessary and inappropriate traditional dental treatments in an attempt to alleviate the neurovascular pain.