J Korean Assoc Oral Maxillofac Surg.  2015 Jun;41(3):165-167. 10.5125/jkaoms.2015.41.3.165.

Screening for variations in anterior digastric musculature prior to correction of post-traumatic anterior open bite by injection of botulinum toxin type A: a technical note

• Zdilla MJ

• KMID: 1797848
• DOI: http://doi.org/10.5125/jkaoms.2015.41.3.165

Abstract

It has recently been reported that long-standing post-traumatic open bite can be successfully corrected with botulinum toxin type A (BTX-A) injection into the anterior belly of the digastric muscle (ABDM). The report documented an individual with bilaterally symmetrical and otherwise unremarkable anterior digastric musculature. However, the existence of variant anterior digastric musculature is common and may complicate the management of anterior open bite with BTX-A injection. Screening for variant ABDM can be accomplished via ultrasound, computed tomography, and magnetic resonance imaging. Screening for variant ABDM should be performed prior to BTX-A injection in order to account for musculature that may exert undesired forces, such as inferolateral deviation, on the anterior mandible in patients with anterior open bite.

Keyword

Nerve block; Malocclusion; Mandibular injuries; Orthognathic surgery; Regional anatomy

MeSH Terms

Anatomy, Regional
Botulinum Toxins, Type A*
Humans
Magnetic Resonance Imaging
Malocclusion
Mandible
Mandibular Injuries
Mass Screening*
Nerve Block
Open Bite*
Orthognathic Surgery
Ultrasonography
Botulinum Toxins, Type A

Figure

• 

  Fig. 1 Side-by-side comparison between normal and variant anterior digastric musculature with regard to botulinum toxin type A (BTX-A) injection sites. A. The line drawing from Seok et al.1, illustrating the BTX-A injection sites in bilaterally symmetrical anterior digastric muscle bellies (starburst with arrow: injection site). Image from the article of Seok et al. (J Korean Assoc Oral Maxillofac Surg 2013;39:188-92)1. B. A cadaveric example of an accessory oblique anterior digastric muscle belly crossing from the left digastric fossa of the mandible to the right intermediate tendon of the right digastric muscle that may complicate BTX-A injection for the correction of posttraumatic anterior open bite. Note that no injection site corresponding to those in Fig. 1. A is located on the accessory oblique digastric belly. (OB: oblique belly of the anterior digastric muscle, asterisk: injection site that correspond to those in Fig. 1. A). Image modified from the article of Zdilla et al. (J Surg Case Rep 2014. doi: 10.1093/jscr/rju131)7.

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