Trigger Point Therapy: Digastricus

About the digastricus

From the Latin digastricus: having two (muscle) bellies

Origin

Anterior belly (a): digastric fossa on the inner side of the lower border of the mandible, near symphysis.
Posterior belly (b): mastoid notch of the temporal bone.

Insertion

Body of hyoid bone via a fascial sling over an intermediate tendon.

Action

Raises hyoid bone. Depresses and retracts mandible as in opening the mouth.

Nerve

Anterior belly: mylohyoid nerve, from trigeminal V nerve (mandibular division).
Posterior belly: facial (V11) nerve.

Trigger Point Referred Pain 

Anterior: lower four incisor teeth, tongue, and lip, occasionally to chin.
Posterior: strong 2 cm zone around mastoid and vaguely the zone to chin and throat, occasionally to scalp.

Indications

Throat pain, dental pain (four lower incisors), headache, jaw pain,
renal tubular acidosis, prolonged/ extensive dental work (blurred vision and dizziness), lower mouth opening, difficulty swallowing, vocal/singing problems.

Causes

• Head-forward/upper crossed pattern
• poor bite mechanics and/or clenching/grinding of teeth (bruxism)
• whiplash
• telephone to chin
• musical instruments (e.g. violin or wind instruments)

Differential Diagnosis

• Dental problems—malocclusion
• Hyoid bone
• Thyroid problems
• Thymus gland
• Sinusitis
• Carotid artery

Connections

• SCM
• sternothyroid
• mylohyoid
• stylohyoid
• longus colli/capitis
• geniohyoid
• cervical vertebrae
• temporalis
• masseter

General Self Help:

Bite Plates/Blocks/Occlusal Splints

Opinion varies as to the efficacy, type, and duration of use for occlusal devices. An evidence base suggests they can be beneficial.

Advice

• Breathing patterns
• Bruxism
• Head postures

Posture

Head forward or upper crossover patterns can be treated by a range of manual and trigger point therapists.

Learn more

Treating TMJ Disorders

About the author

Stuart Hinds is one of Australia’s leading soft tissue therapists, with over 27 years of experience as a practitioner, working with elite sports athletes, supporting Olympic teams, educating and mentoring others as well as running a highly successful clinic in Geelong.

Stuart has a strong following of practitioners across Australia and globally who tap into his expertise as a soft-tissue specialist. He delivers a range of highly sought after seminars across Australia, supported by online videos, webinars and one-on-one mentoring to help support his colleagues to build successful businesses.

In 2016, Stuart was awarded a lifetime membership to Massage & Myotherapy Australia for his significant support and contribution to the industry.

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This trigger point therapy blog is intended to be used for information purposes only and is not intended to be used for medical diagnosis or treatment or to substitute for medical diagnosis and/or treatment rendered or prescribed by a physician or competent healthcare professional. This information is designed as educational material, but should not be taken as a recommendation for treatment of any particular person or patient. Always consult your physician if you think you need treatment or if you feel unwell.