1. Platysma
Origin: Skin of infra- and supraclavicular regions
Insertion: lower bone of the mandible, skin of the cheek region, lower lip, modiolus, and orbicularis oris muscle
Action: draws the corners of the mouth downwards, tenses the skin of lower face, depresses the lower jaw
2. Mentalis
Origin: incisive fossa of the mandible
Insertion: skin of chin (Mentolabial sulcus)
Action: elevates and protrudes lower lip, wrinkles skin of the chin
3. Orbicularis oris
Origin: Medial aspects of maxillia and mandible, other muscles of the cheek, mediolus
Insertion: Skin and mucous membranes of the lips
Action: Closes mouth, compresses and purses the lips
4. Corrugator supercilia
Origin: medial part of superciliary arch, running in a superolateral direction
Insertion: into the skin above the middle part of the eyebrow
Action: pulls skin of eyebrows together downward and medially, producing vertical wrinkles on forehead
5. Orbicularis oculi
Origin: Nasal part of frontal bone, frontal process of maxilla, medial palpebral ligament, lacrimal bone
Insertion: Skin around the orbital region, lateral palpebral raphe, and the superior and inferior tarsal plates
Action: closes the eyelids gently (palpebral part), drainage of tears (lacrimal part), and tightly closes the eyelids (orbital part)
6. Occipitofrontalis
Origin: Epicranial aponeurosis
Insertion: into the fascia of the facial muscles
Action: Frontal belly: Elevates eyebrows, wrinkles skin of forehead, and Occipital belly: Retracts scalp
References:
MD, G. S. (2022, July 6). Platysma. Kenhub. Retrieved September 23, 2022, from https://www.kenhub.com/en/library/anatomy/the-platysma
MD, J. V. (2022, August 2). Mentalis muscle. Kenhub. Retrieved September 23, 2022, from https://www.kenhub.com/en/library/anatomy/mentalis-muscle
MD, J. V. (2022, July 6). Occipitofrontalis muscle. Kenhub. Retrieved September 23, 2022, from https://www.kenhub.com/en/library/anatomy/occipitofrontalis-muscle