Head and neck muscles (chewing, facial, and throat muscles)
Mentalis Muscle
Musculus mentalis
- Origin
- Incisive fossa of the mandible, below the incisors
- Insertion
- Skin of the chin
- Function
- Raises and wrinkles the skin of the chin, and everts the lower lip forward (e.g. pouting or holding liquid in the mouth)
- Innervation
- Marginal mandibular branch of the facial nerve (CN VII)
- Movement & chain
- Raises and wrinkles the skin of the chin and everts the lower lip forward; a mimetic movement.
- Palpation
- Palpable as a nodular firmness on the chin when the lower lip is actively pushed forward ('pouting').
- Clinical
- Overactivity produces the 'orange-peel' chin pattern; relevant in orthodontic assessment of lip closure.
- Segmental innervation
- CN VII, motor.
- In clinical practice
- Elevates and puckers chin skin ('peau d'orange' chin); botulinum toxin for mentalis strain/hyperactivity; lip competence therapy.
- Region in the model
- Head and neck muscles (chewing, facial, and throat muscles)