The Use of Low-Dose Botulinum Toxin Injection Into the Masseter Muscle to Treat Sleep Bruxism
Condition: Nocturnal Bruxism
MeSH terms: Bruxism; Sleep Bruxism
Study type: Interventional

Summary: 
      Botulinum toxin (BOTOX®) injections into the masseter muscle are an effective treatment for
      nocturnal bruxism, with several trials using various dosages of botulinum toxin for this
      purpose. The aim was to evaluate the effectiveness of injecting 10MU of botulinum toxin A
      (BTXA) into the masseter muscle to reduce nocturnal bruxism, the sample will randomly divided
      into 2 groups.

      In the injection group, Patients will inject with 10 MU of botulinum toxin type A (BOTOX® -
      Allergan Inc. - Dublin - Ireland) per side at two sites into the masseter muscle bilaterally.

      In this Placebo group, patients will prick twice at the inferior prominent part of the
      masseter muscle observed using the stinger pen used in the blood glucose meter.

      The evaluation will make by Electromyography (EMG) analysis, Visual Analogue Scale (VAS)
      values.
    

Detailed description: 
      Nocturnal bruxism (NB) is a disorder of maxillomandibular activity characterized by
      nonfunctional grinding and clenching of teeth while sleeping.

      NB can cause teeth attrition, dental prostheses/implant failure, tooth sensitivity, pain in
      the teeth, jaw, masticatory muscle, and temporomandibular joint (TMJ), neck pains and
      headache, periodontal disease, oral or facial pain, and perhaps tooth loss. The diagnosis of
      nocturnal bruxism is based on complaints of tooth grinding or clenching, as well as one or
      more of the following signs: nonfunctional teeth attrition, sounds consistent with bruxism,
      and jaw muscle discomfort. Teeth wear and TMJ dysfunction can both be caused by bruxism. In
      some circumstances, delaying therapy might lead to luxation and degenerative arthritis of the
      temporomandibular joint.

      For the treatment of bruxism, many treatment approaches such as occlusal splints and
      pharmacologic medications such as psychobehavioral therapy or L-dopa, and psychobehavioral
      therapy have been examined but is not enough evidence to define a standard of reference
      approach for SB treatment.

      Botulinum toxin (Botox®) is an exotoxin generated by the bacteria Clostridium botulinum that
      causes muscle inactivity by blocking acetylcholine release from cholinergic nerve terminals
      into the neuromuscular junction. In the last two decades, several studies have been conducted
      to investigate the efficacy of botulinum toxin type A (BTXA) in reducing nocturnal bruxism,
      and the results have been promising. These studies have used different doses of botulinum
      toxin ranging from 20 mouse units (MU) and 25 MU to 30 MU in the masseter. Most of these
      studies did not take into account the relationship between the amount of botulinum toxin dose
      and alteration of the masseter muscle's size and the shape of the lower third of the face,
      where injection of more than 20 MU into the masseter muscle affects its size and is an
      effective treatment for masseter muscle hypertrophy for at least 9 months. To avoid the
      unwanted side effects of doses greater than 20 MU, the trial aimed to evaluate the
      effectiveness of injecting 10 MU of the Botulinum toxin into the masseter muscle in reducing
      the nocturnal bruxism.

      The idea of the research will explain to all patients, and the information sheets will
      distribute to them, then their consent will obtain.
    

Intervention name(s): BOTOX® Injection; Prick skin
Intervention type(s): Drug; Other
Intervention description(s): 100 MU of botulinum toxin type A (BOTOX® - Allergan Inc. - Dublin - Ireland) were diluted in 2ml of saline. Patients were injected with 10 MU of BTXA per side at two sites into the masseter muscle bilaterally. The first site was the inferior prominent part of the masseter muscle observed when the subject was asked to clench, and the other site was 5 mm below the first point; patients were pricked twice at the inferior prominent part of the masseter muscle observed using the stinger pen used in the blood glucose meter; it is less painful and provides psychological benefits, instead of injecting the physiological saline into the muscle to avoid the severe pain without a benefit to the patient which would not conform to the ethical standards.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Nocturnal bruxism; Botulinum toxin; Masseter muscle; Electromyography