Search databaseBooksAll DatabasesAssemblyBiocollectionsBioProjectBioSampleBioSystemsBooksClinVarConserved DomainsdbGaPdbVarGeneGenomeGEO DataSetsGEO ProfilesGTRHomoloGeneIdentical Protein GroupsMedGenMeSHgimpppa.org web Sitegimpppa.org CatalogNucleotideOMIMPMCPopSetProteinProtein ClustersProtein family ModelsPubChem BioAssayPubChem CompoundPubChem SubstancePubMedSNPSRAStructureTaxonomyToolKitToolKitAllToolKitBookgh

gimpppa.org Bookshelf. A service of the national Library that Medicine, nationwide Institutes of Health.

You are watching: What muscle pulls the scalp posteriorly

StatPearls . Sweetheart Island (FL): StatPearls Publishing; 2021 Jan-.


*

Anatomy, Head and Neck, Frontalis Muscle

Kenneth Pessino; Jay Patel; Bhupendra C. Patel.

Author Information

Introduction

The frontalis muscle theatre a far-reaching role in ours day-to-day social interactions. As the only muscle the raises the eyebrows, its function goes past simply keeping the brows the end of one’s visual field; it is likewise necessary for conveying emotions and also nonverbal communication. The antagonist muscle to the frontalis muscle are the procerus muscle, the corrugator supercilii muscle, and the orbicularis oculi muscle. (Fig 1) The frontalis, corrugator, procerus, and also orbicularis muscles all have actually cutaneous insertions and have a confluence in ~ the glabella, and the orbit rim, where their respective movements and forces expanded to the skin may reason cutaneous rhytids (frown lines, laugh lines, forehead lines, horizontal nasal lines). The balance between these muscles determines the eyebrow position and also shape. 


Structure and also Function

The frontalis muscle is top top the former of the head, and while it may seem come behave together an live independence muscle, it is actually part of a larger structure described as the occipitofrontalis muscle or epicranius.<1> A beneficial tool because that remembering the great of the scalp is the acronym SCALP:

S: Skin

C: subCutaneous connective tissue

A: Aponeurosis (galea)

L: loose areolar connective tissue

P: Periosteum

The occipitofrontalis is written of two muscle bellies: frontalis and occipitalis, which are attached and encased by thick connective tissue referred to as the epicranial aponeurosis or galea aponeurotica. The occipital part of the occipitofrontalis muscle moves the scalp forwards, and the frontalis component lifts the brows and also moves the anterior scalp backward. As soon as the frontalis muscle contracts, the upright fibers traction the skin of the eyebrows upward.

The superficial musculoaponeurotic mechanism (SMAS) continues above the zygomatic arch and also includes the temporoparietal fascia (as that blends right into the galea) and also the frontalis muscle as part of the SMAS. 

The antagonist muscles to the frontalis muscle are the orbicularis oculi, corrugated, and procerus muscles. The frontalis muscle has no bony attachments. The corrugator muscle is below the frontalis and the orbicularis muscles and has a bony origin from the medial orbital rim.

Surface Anatomy

Frontalis muscle activity produces horizontal forehead lines. Four species of forehead lines have actually been described <2>:


Full, straight lines that run across the whole forehead (45%)
Gull wing-shaped lines through a main depression and also lateral key (30%)
Short main horizontal lines end the center of the forehead but few or no currently laterally (10%)

Blood Supply and Lymphatics

The frontalis muscle receive its blood supply from branches the both the internal and external carotid arteries. The supratrochlear and also supraorbital arteries supply the muscle native the worse margin after they exit the orbit and also travel increase the forehead. The supraorbital artery can exit from the supraorbital notch/foramen, if the supratrochlear artery exits an ext medially indigenous the orbit. They are both branches the the ophthalmic artery, i beg your pardon is a branch that the internal carotid artery. Shortly after their particular exits, the supratrochlear and also supraorbital arteries separate additional into both superficial and deep branches.<4><5> The superficial arteries it is provided the muscle, galea, and also skin, if the depths layer supplies the periosteum. The supratrochlear and supraorbital arteries supply a mass of the blood medially, and the frontal branch, which comes off of the superficial temporal artery, provides the muscle an ext laterally. The arteries type an anastomosis with one another to form a extremely vascularized network.

The lymphatic drainage that the forehead is facility and no well understood. Researches looking in ~ the drainage have discovered that the an ext lateral portion of the forehead most most likely drains differently than the medial portion.<6> Regardless, it shows up the forehead drains mainly into the preauricular nodes and also parotid nodes.<6><7>

The main venous drainage occurs between three veins: the supratrochlear vein being many medial, climate the intermediary supraorbital vein, and also finally, the lateral frontal vein. The three further connect through a transverse vein that runs remarkable to the orbit, accordingly named the transverse supraorbital vein <8>. The transverse supraorbital vein connects medially come the angular vein, which eventually drains into the ophthalmic vein and cavernous sinus. It is important to psychic this relationship as soon as considering the hazard of outside facial infections causing potentially harmful intracranial infections or cavernous sinus thrombosis.


Nerves

The muscle of face expression get nerve it is provided from cranial nerve VII (the face nerve), i beg your pardon separates into five main branches: temporal, zygomatic, buccal, marginal mandibular, and also cervical. The face nerve exits the skull in ~ the stylomastoid foramen and its temporal branch the cross over the zygomatic arch, passes with the areolar organization on the surface of the temporal fascia, and also subsequently enters right into the frontalis muscle to carry out its deep innervation. 3 branches the the temporal nerve, the anterior, middle, and posterior, are responsible for innervating the orbicularis oculi, frontalis, and the corrugator muscles.<9> The temporal (also dubbed the frontal) branch that the face nerve runs within the superficial class of the temporoparietal fascia, through the temporal artery just anterior come the nerve. The temporal branch enters the frontalis muscle right into its depth part. Injury to the temporal branch the the facial nerve is avoided by one of two people dissecting subcutaneously or just anterior to the superficial part of the deep temporal fascia (the glistening layer in former of the temporalis muscle).

The supratrochlear and supraorbital nerves that operation along their particular arteries, permeate through the frontalis in stimulate to reach the superficial skin. These are branches the the ophthalmic division of the trigeminal nerve and also do not directly innervate the muscle, yet instead innervate the overlying skin. The medial branches that the supraorbital nerve room superficial and also the lateral branches are deep.


Muscles

The frontalis muscle is comprised of upright striations in a fan-like distribution. Clinically, the muscle is sometimes split into medial, intermediate and lateral fibers, return no anatomical or histological distinguish exist. That originates posteriorly indigenous the galea aponeurotica, which synchronizes with the hairline ~ above the surface. Inferomedially, the muscle interdigitates with fibers that procerus muscle, while more inferolaterally, it has attachments to the orbicularis oculi and also corrugator muscles. Generally, the frontalis inserts in ~ the eyebrow dermis and also terminates laterally at the temporal ridge, but there is some variance and also occasionally might terminate more medially together well.<10><11> While overall, that is a slim muscle v high vascularity, the mass of it is located right above the brow. The is thinnest laterally, which represents an area the weakness and the first area to sag together we age.


The lateral-most degree of the frontalis muscle where it interdigitates v the orbital orbicularis muscle varies: as soon as measured from the supraorbital notch, it may be small, medium, or large. (Fig 2) The exact circulation in the normal population is unknown. However, the lateral brow will have actually less support from the frontalis in topics that have actually a smaller sized horizontal frontalis muscle, thereby resulting in more significant brow ptosis and lateral brow ptosis with second dermatochalasis in particular
The angle between where the frontalis interdigitates with the orbit orbicularis muscle (the frontalis-orbicularis angle) might be small, medium, and also large, and also there is evidence that that may end up being smaller through age, in order to causing further lateral brow ptosis and second dermatochalasis. (Fig 4)
The lateral sheet of the frontalis muscle may prolong to the linea temporalis (temporal ridge or crest), or may extend beyond it or may fall brief of it.

Surgical Considerations

An knowledge of frontalis anatomy is important for reconstructive and also cosmetic procedures. In cases where children are born through an absent or dysfunctional levator palpebrae superioris, such together in bilateral congenital ptosis, the ptosis have the right to be so substantial that it leader to vision obstruction and amblyopia. In those patients, frontalis-orbicularis muscle breakthrough is possible. This procedure, first described end 100 years ago, now entails making an incision at the folds of the upper eyelid, followed by vertical incisions into the frontalis muscle. Finally, the muscle flap is progressed inferiorly to type a connection with the orbicularis oculi muscle.<14> Another choice for ptosis correction making use of the frontalis is referred to as a frontalis sling or frontalis suspension. This procedure is regularly favored end a muscle flap advance and entails a similar approach, other than that it provides a suture to affix the frontalis come the tarsal plate.<15> Similar to the flap, this supplies the vital pull to elevate the eyelid v frontalis contraction. Ptosis have the right to be second to mechanical, neurological, traumatic, and muscular dysfunctions, for every one of which surgery deserve to be the potential last line of defense.<16>


Clinical Significance

Improvement the forehead skin:

The forehead is a website that many people seek to rejuvenate to preserve a youthful appearance. Peaceful skin anxiety lines, likewise called wrinkles, form perpendicular come the basic muscles and as we age. A trial of nonsurgical choices is regularly the first step to try and alleviate lines, vascular changes, and skin pigment changes. Nonsurgical choices can include creams, peels, abrasives, and also lasers.<17>

Use that botulinum toxin for forehead and also frown lines:

The prestige of anatomy theatre a role when dealing with minimally invasive steps like botulinum injections. Botulinum toxin is an effective tool for dealing with rhytides and also wrinkles and can it is in injected directly into the frontalis muscle. The decreased muscular contraction leader to a decrease in rhytid production and a much more youthful appearance. This procedure requires multiple injections right into the frontalis. The target is come avoid finish paralysis of the frontalis muscle: 10 come 20 units of botox distributed throughout the forehead yields satisfactory be sure of the horizontal rhytids. When injecting the frontalis, the corrugator and also procerus muscle should additionally be injected. A for sure zone for frontalis muscle injections is 2 cm above the brow. If done improperly, the toxin have the right to spread come the levator palpebrae superioris and also lead to nonpermanent ptosis. Also, the is important to keep the balance in between the depressors the the brow and also the levators. A weak frontalis muscle and also dominant set of depressors would cause the brow to descend. Also, improper circulation of botulinum into the medial frontalis deserve to lead come a "Spock" deformity, in i m sorry the lateral part of frontalis is qualified of contraction, however the medial section is relaxed. The various other area of frontalis action, specifically in ladies that often goes undertreated is wherein the frontalis is close to the anterior hairline, which results in influential residual high horizontal rhytids. 

Fillers because that grooves at the glabella:

Fillers are additionally often put into the forehead to create volume and also fullness in the horizontal wrinkles at the source of the sleep (caused by the procerus muscle) and the verticle "elevenses" at the medial end of each brow, led to by the corrugator muscles. Knowing the basic anatomy, including the depth and location of the miscellaneous muscles, is vital for avoiding devastating complications throughout injections. For example, too lot filler or misplaced filler when targeting the glabella (the region between the eyebrows and above the nose) can lead to a retinal artery occlusion and blindness.<4> An unreasonable injection right into an artery, because that example, the supratrochlear, could lead come acute necrosis the the tissue. Fillers are never injected with pressure or in boluses. An additional approach we have found to be safe is to pinch the skin upwards with small amounts of filler injected gently. 

Upper and also lower motor neuron face palsy:

Understanding the nerve it is provided to the forehead is likewise essential when analyzing a patient with a potential stroke. Center cerebral artery strokes can reason contralateral facial paralysis, but these strokes often spare the forehead. This presentation is since the lower motor neurons responsible for innervating the top half of the challenge receive input native both hemispheres, if the lower half does not. If the injury is in ~ the level that the reduced motor neuron, as seen through Bell palsy, climate we check out a complete hemifacial paralysis.

Tissue expansion:

Tissue growth is essential when repairing big forehead or nasal defects. Whereas in the neck, expanders are placed in prior of the platysma, in the forehead, that is vital to ar expanders under the frontalis muscles, through insertion via incisions made within the hairline. 


The frontalis muscle is actually part of the occipitofrontalis muscle, i beg your pardon is 2 muscle bellies associated by the galea aponeurotic.
The frontalis muscle is responsible because that elevating the eyebrows, if the corrugator supercilii, orbicularis oculi, and procerus play a function in its depression. 
To avoid injury come the sensory and also motor nerves come the frontalis muscle, dissection planes have to be subcutaneous, subperiosteal or subgaleal.

See more: Chem Is Heating Copper A Chemical Change S, If I Hold A 5


The variations in the horizontal level of the frontalis muscle must be appreciated together these sports may have a bearing ~ above the degree of brow ptosis.
The surface and applied anatomy the the forehead and the degree of the frontalis muscle must be appreciated as soon as performing surgery in this region or injecting toxins. (Fig 5)