The management of oromandibular motor disorders and facial spasms with injections of botulinum toxin

A Novel Injection Technique to the Lateral Pterygoid Muscle for Temporomandibular Disorders: A Cadaveric Study

BACKGROUND

Lateral pterygoid muscle activity is associated with the pathological mechanisms of some temporomandibular disorders. The authors aimed to define and demonstrate a novel, practical, and safe technique for botulinum toxin type A injection to the lateral pterygoid muscle based on their findings. Their secondary aims were to standardize the injection pattern according to the variations of the lateral pterygoid muscle and its surrounding anatomical structures, and to establish its advantages over intraoral injection.

METHODS

Twenty cadaver heads were dissected. The lateral pterygoid muscle and its surrounding structures were investigated for anatomical variations. Based on these findings, a standardized extraoral injection protocol was defined and compared with the intraoral technique for accuracy and safety.

RESULTS

The average depth of the lateral pterygoid plate from the skin surface was 49.9 ± 2.2 mm, and the mean width of the lateral pterygoid plate was 10.5 ± 3.9 mm. The extraoral injection approach based on the location of the maxillary tuberosity, tragus, and lateral pterygoid plate was consistent in all dissections for the accuracy of the intramuscular injection. In the intraoral approach, standardization of the entry point of the needle through the oral mucosa is difficult, which makes adjustment of the depth of the injection challenging while increasing the risk of neurovascular injury.

CONCLUSIONS

The clinical significance of the lateral pterygoid muscle makes it worthwhile to implement minimally invasive treatments before considering more invasive options. The authors define a safe, accurate, and reliable approach with ease of administration in patients with temporomandibular disorders.

The Consequences of Oromandibular Dystonia on Communicative Participation: A Qualitative Study of the Insider's Experiences

Purpose The purpose of this study was to obtain a self-reported account of the experience of living with oromandibular dystonia (OMD) to gain a better understanding of both the daily facilitators and barriers to communicative participation and the strategies used for adapting to life with OMD. Method Eight individuals with OMD and dysarthria participated in 1 face-to-face, semistructured interview. Interviews were audio-recorded and transcribed verbatim. Qualitative, phenomenological methods of coding, immersion, and emergence were used in the analysis of interview data. Results Three major themes and 7 subthemes emerged from the analysis of interview data. First, "speaking is different now" provided examples of how speech changes are manifested in various life situations. Second, "my roles have changed" addressed how OMD has impacted work, home, and social roles. Third, "I accept it and move on" involved finding strategies that help and adopting a different perspective. Conclusion We suggest that the management of OMD must take a more holistic approach by addressing consequences beyond the physical symptoms and be tailored to each individual based on his or her personal concerns and goals.

Dental Management of Patients Who Have Undergone Oral Cancer Therapy

Oral cancer therapies are associated with orofacial complications that could result in dose-limiting cancer treatment and consequent suboptimal tumor control. Oral cancer treatment complications include oral mucositis, salivary gland hypofunction, odontogenic infections, pain, dermatitis, neurotoxicity, soft tissue fibrosis, trismus, osteoradionecrosis, and potential cancer recurrence. These complications significantly affect cancer survivorship, quality of life, and psychosocial status. Effective dental management of patients with oral cancer involves the coordination of care among several health care professionals before, during, and after cancer therapy. The goal is to minimize complications, and establish optimal quality of life for survivors.

BOTOX: Broadening the Horizon of Dentistry

Botox has been primarily used in cosmetic treatment for lines and wrinkles on the face, but the botulinum toxin that Botox is derived from has a long history of medically therapeutic uses. For nearly 13 years, until the introduction of Botox Cosmetic in 2002, the only FDA-approved uses of Botox were for crossed eyes (strabismus) and abnormal muscle spasms of the eyelids (blepharospasm). Since then botulinum A, and the seven other forms of the botulinum toxin, have been continuously researched and tested. Botox is a neurotoxin derived from bacterium clostridium botulinm. The toxin inhibits the release of acetylcholine (ACH), a neurotransmitter responsible for the activation of muscle contraction and glandular secretion, and its administration results in reduction of tone in the injected muscle. The use of Botox is a minimally invasive procedure and is showing quite promising results in management of muscle-generated dental diseases like Temporomandibular disorders, bruxism, clenching, masseter hypertrophy and used to treat functional or esthetic dental conditions like deep nasolabial folds, radial lip lines, high lip line and black triangles between teeth.

Change of distribution and timing of bite force after botulinum toxin type A injection evaluated by a computerized occlusion analysis system

PURPOSE

The aim of this study was to determine the force distribution and pattern of mastication after injection of botulinum toxin type A (BTX-A) into both masseter muscles. The hypothesis to be tested was that the difference between right and left balance of occlusal force diminishes over time following BTX-A injection.

MATERIALS AND METHODS

Fifteen patients were submitted to BTX-A injection therapy for subjective masseter hypertrophy. A total of 25 U of BTX-A (50 U in total) was injected into two points located 1 cm apart at the center of the lower one-third of both masseter muscles. All patients were examined using the T-Scan occlusion analysis system before and 4, 8, 12, and 24 weeks after BTX-A injection.

RESULTS

A significant change in force balance was found between the right and left sides over time and the difference between the two sides decreased with the time post-injection, reaching a minimum at 12 weeks. Comparison of the force balance between the anterior and posterior occlusions revealed no significant difference at any of the time points. The occlusion and disclusion times (right and left sides) did not differ significantly with time since BTX-A injection.

CONCLUSION

A decline in the difference in the clenching force between the left and right sides was found with increasing time up to 12 weeks following BTX-A injection.

Botulinum toxin: The Midas touch

Botulinum Toxin (BT) is a natural molecule produced during growth and autolysis of bacterium called Clostridium botulinum. Use of BT for cosmetic purposes has gained popularity over past two decades, and recently, other therapeutic uses of BT has been extensively studied. BT is considered as a minimally invasive agent that can be used in the treatment of various orofacial disorders and improving the quality of life in such patients. The objective of this article is to review the nature, mechanism of action of BT, and its application in various head and neck diseases.

Effects of botulinum toxin on jaw motor events during sleep in sleep bruxism patients: a polysomnographic evaluation

STUDY OBJECTIVES

To investigate the effects of botulinum toxin type A (BoNT-A) injection on jaw motor episodes during sleep in patients with or without orofacial pain who did not respond to oral splint treatment.

METHODS

Twenty subjects with a clinical diagnosis of SB completed this study. Ten subjects received bilateral BoNT-A injections (25 U per muscle) into the masseter muscles only (group A), and the other 10 received the injections into both the masseter and temporalis muscles (group B). Video-polysomnographic (vPSG) recordings were made before and at 4 weeks after injection. Rhythmic masticatory muscle activity (RMMA) and orofacial activity (OFA) were scored and analyzed for several parameters (e.g., frequency of episodes, bursts per episode, episode duration). The peak amplitude of electromyographic (EMG) activity in the two muscles was also measured.

RESULTS

BoNT-A injection did not reduce the frequency, number of bursts, or duration for RMMA episodes in the two groups. The injection decreased the peak amplitude of EMG burst of RMMA episodes in the injected muscles (p < 0.001, repeated measure ANOVA) in both groups. At 4 weeks after injection, 9 subjects self-reported reduction of tooth grinding and 18 subjects self-reported reduction of morning jaw stiffness.

CONCLUSIONS

A single BoNT-A injection is an effective strategy for controlling SB for at least a month. It reduces the intensity rather than the generation of the contraction in jaw-closing muscles. Future investigations on the efficacy and safety in larger samples over a longer follow-up period are needed before establishing management strategies for SB with BoNT-A.

CITATION

Shim YJ; Lee MK; Kato T; Park HU; Heo K; Kim ST. Effects of botulinum toxin on jaw motor events during sleep in sleep bruxism patients: a polysomnographic evaluation.

Review of the complications associated with treatment of oropharyngeal cancer: a guide for the dental practitioner

OBJECTIVES

Oropharyngeal cancer (OPC) is the sixth most common cancer worldwide. Focus on risk factors, improved diagnostic methods and effective management strategies have made it possible to successfully treat OPC. However, the 5-year survival rate has not improved for several years due to multiple treatment complications, tissue morbidity, loss of function, and diminished quality of life. Survivors are faced with complications like oral mucositis, hyposalivation, osteoradionecrosis, tissue fibrosis, morbidity from jaw resection, disfigurement, and loss of function that further diminish quality of life. The aim of this review is to highlight major complications associated with treatment of OPC via a literature search and review of available options for identification and management of these complications.

DATA SOURCES

Relevant publications on oral complications of OPC therapy were thoroughly reviewed from the literature published between the years 1988 and 2012. We evaluated reported incidence, prevalence, and risk factors for oral complications of chemotherapy and radiotherapy for OPC. The authors conducted an electronic search using English language databases, namely PubMed Plus, Medline (Pre-Medline and Medline), Cochrane Database of Systematic Reviews (evidence-based medicine), Dentistry & Oral Sciences Source, A ccessScience, Embase, Evidence-Based Medicine Reviews Multifile, Google Scholar, ISI Journal Citation Reports, and Ovid Multi-Database.

CONCLUSION

We identified the most common complications associated with the treatment of oral cancers. Based on the information gathered, there is evidence that survival of OPC extends beyond eradication of the diseased tissue. Understanding the potential treatment complications and utilizing available resources to prevent and minimize them are important. Caring for OPC survivors should be a multidisciplinary team approach involving the dentist, oncologist, internist, and social worker to improve the currently stagnant 5-year survival rate of OPC. More emphasis on improved quality of life after elimination of the cancer will ultimately improve OPC survivorship.

Adult-onset dystonia

Dystonia is defined as involuntary sustained muscle contractions producing twisting or squeezing movements and abnormal postures. The movements can be stereotyped and repetitive and they may vary in speed from rapid to slow; sustained contractions can result in fixed postures. Dystonic disorders are classified into primary and secondary forms. Several types of adult-onset primary dystonia have been identified but all share the characteristic that dystonia (including tremor) is the sole neurologic feature. The forms most commonly seen in neurological practice include cranial dystonia (blepharospasm, oromandibular and lingual dystonia and spasmodic dysphonia), cervical dystonia (also known as spasmodic torticollis) and writer's cramp. These are the disorders that benefit most from botulinum toxin injections. A general characteristic of dystonia is that the movements or postures may occur in relation to specific voluntary actions by the involved muscle groups (such as in writer's cramp). Dystonic contractions may occur in one body segment with movement of another (overflow dystonia). With progression, dystonia often becomes present at rest. Dystonic movements typically worsen with anxiety, heightened emotions, and fatigue, decrease with relaxation, and disappear during sleep. There may be diurnal fluctuations in the dystonia, which manifest as little or no involuntary movement in the morning followed by severe disabling dystonia in the afternoon and evening. Morning improvement (or honeymoon) is seen with several types of dystonia. Patients often discover maneuvers that reduce the dystonia and which involve sensory stimuli such as touching the chin lightly in cervical dystonia. These maneuvers are known as sensory tricks, or gestes antagonistes. This chapter focuses on adult-onset focal dystonias including cranial dystonia, cervical dystonia, and writer's cramp. The chapter begins with a review of the epidemiology of focal dystonias, followed by discussions of each major type of focal dystonia, covering clinical phenomenology, differential genetics, and diagnosis. The chapter concludes with discussions of the pathophysiology, the few pathological cases published of adult-onset focal dystonia and management options, and a a brief look at the future.

Orofacial movement disorders

This article reviews three poorly recognized yet relatively common presentations of hyperactive orofacial movement disorders: oromandibular dystonia, orofacial dyskinesia, and drug-induced extrapyramidal syndrome reactions. Orofacial movement disorders are often misdiagnosed as temporomandibular disorders, hence understanding these conditions is pertinent for the practitioner treating orofacial pain. Aspects of epidemiology, etiology, pathophysiology, clinical presentation, and diagnosis are discussed along with treatment considerations for these orofacial movement disorders.

Botulinum toxin for radiation-induced facial pain and trismus

OBJECTIVE

To report the efficacy of botulinum toxin A for radiation-induced pain, trismus, and masticator spasm in head and neck cancer.

PATIENTS AND METHODS

This prospective nonrandomized study included patients in complete remission with radiation-induced pain and trismus with or without masticator spasms. Fifty units of Botox (Allergan) or 250 units of Dysport (Ipsen) were injected transcutaneously into the masseter muscles. Jaw opening was measured and patients answered 20 questions about jaw opening, pain, and cramps, before injection at 1 month.

RESULTS

Nineteen patients (7 women, 12 men) were included. Median time after radiation therapy was 5 years (range, 11 months to 22 years). At 1 month, no significant increase in jaw opening was recorded. Improvement was noted in the functional domain (P = 0.004), for pain (P = 0.002) and cramps (P = 0.004), but not in the social (P = 0.83) or emotional (P = 0.43) domains. No side effects occurred.

CONCLUSIONS

Botulinum toxin did not improve trismus but significantly improved pain scores and masticator spasms (oromandibular dystonia).

Orofacial pain and neurosensory disorders and dysfunction in cancer patients

Orofacial pain and altered nerve sensation may be the initial sign of oropharyngeal or nasopharyngeal cancer. This article focuses on the most common orofacial pain conditions and neurosensory alterations that affect cancer patients, such as neuropathic pain, muscle spasm or contractures, mucositis, and increased or decreased sensory discrimination in the affected area. The various pharmacotherapeutic modalities for cancer pain management ranging from non steroidal anti-inflammatory drugs (NSAIDs) for mild pain to opioids for severe pain are discussed in detail.

Four oral motor disorders: bruxism, dystonia, dyskinesia and drug-induced dystonic extrapyramidal reactions

This article reviews four of the involuntary hyperkinetic motor disorders that affect the orofacial region: bruxism, orofacial dystonia, oromandibular dyskinesia, and medication-induced extrapyramidal syndrome-dystonic reactions. It discusses and contrasts the clinical features and management strategies for spontaneous, primary, and drug-induced motor disorders in the orofacial region. The article provides a list of medications that have been reported to cause drug-related extrapyramidal motor activity, and discusses briefly the genetic and traumatic events that are associated with spontaneous dystonia. Finally, it presents an approach for management of the orofacial motor disorders. The contraindications, side effects, and usual approach for medications and injections are covered. An overview of the indications, contraindications, and complications of using botulinum toxin as a therapeutic modality is discussed briefly.

A critical review of the use of botulinum toxin in orofacial pain disorders

This article reviews the appropriate use, cautions, and contraindication for botulinum neurotoxin (BoNT) and reviews the peer-reviewed literature that describes its efficacy for treatment of various chronic orofacial pain disorders. The literature has long suggested that BoNT is of value for orofacial hyperactivity and more recently for some orofacial pain disorders; however, the results are not as promising for orofacial pain. The available data from randomized, double-blind, placebo-controlled trials (RBCTs) do not support the use of BoNT as a substantially better therapy than what is being used already. The one exception is that BoNT has reasonable RBCT data to support its use as a migraine prophylaxis therapy. The major caveat is that the use of BoNT in chronic orofacial pain is "off-label".

Orofacial pain and sensory disorders in the elderly

Many orofacial pain conditions occur in the elderly. Specifically,this article reviews the prevalence of general and orofacial-related pain in the elderly. The authors also describe and discuss the likely disorders and diseases that produce facial pain and burning pain in the mouth. They do not cover jaw joint pain, oral sores, or ulceration-induced pain, as these conditions are better discussed in the context of arthritis and oral pathologies of the mouth. The authors discuss oral motor disorders, myogenous pain, vascular pain, headaches, trigeminal neuralgia, trigeminal neuropathic dis-ease, postherpetic neuralgia, burning mouth syndrome, and occlusal dysesthesia.

Update on botulinum toxin use in facial plastic and head and neck surgery

PURPOSE OF REVIEW

The purpose of this review is to discuss current trends in the medicinal use of botulinum toxin in head and neck and facial plastic surgery. The basic science of botulinum toxin is presented along with a comparison of the subtypes currently available on the market. Site-specific applications of botulinum toxin in the head and neck region are presented.

RECENT FINDINGS

The use of botulinum toxin continues to expand, both in volume and in number of applications. The main application of botulinum toxin in facial plastic surgery is in the effacement of dynamic or hyperkinetic facial lines. The granting of US Food and Drug Administration approval for the use of Botulinum Toxin type A in the treatment of glabella lines marks a major milestone for the more widespread usage of this product in cosmetic settings. Additional cosmetic applications include crow's feet, marionette lines, and platysma banding. Noncosmetic applications in the head and neck include dystonias (including torticollis), facial and generalized muscle spasms, migraine headaches, hyperhidrosis, spasmodic dysphonia, sialorrhea, gustatory sweating, and involuntary movement disorders.

SUMMARY

The use of botulinum toxin in the treatment of hyperkinetic conditions and disorders of excessive salivation is well established and enjoys an excellent safety profile. The cosmetic use of botulinum toxin continues to expand. The chronic use of botulinum toxin specifically for cosmetic purposes is worthy of additional study.