The whole world can identify with the person that has a muscle twitch. Most everyone knows what a “charlie horse” or a muscle spasm is.
Not all twitches are painful or can be seen by others. It depends on where they occur and whether clothing or body position hides the tic from others.
On the simplest level, a muscle is repeatedly contracting and releasing spontaneously.
Our discussion here focuses on the significance of lower lip myoclonus.
Upper and Lower Lips
A casual look at the face reveals several surface structures that comprise our lips.
The upper lip has flesh (the “pillars”) that rises above the other lip tissue (the “philtrum”). These structures connect to our “lips,” the “vermilion” where lipstick or lip balm is applied.
The vermilion is the connecting tissue linking our exterior skin to the interior mucosa and the moisture of the mouth.
These surface structures cover the musculature of the lips. The “orbicularis oris” is the muscle of both the upper and lower lips, nurtured by the “superior and inferior labial arteries.”
The vermilion is nurtured via capillaries. “Salivary glands,” “sebaceous glands,” and various hair cells reside within these lip tissues.(3)
The upper and lower lips receive blood supply via the “external carotid’s” “facial artery.” It proceeds from the neck, supplying the “inferior and superior labial artery” lying beneath the orbicularis oris.
The nervous system’s “subdermal plexus” receives its blood supply from both the facial and labial arteries.(4)
The nervous system consists of efferent nerves from the brain and afferent nerves to the brain. The nerves innervate muscles and verify what is happening via afferent feedback.
The “buccinator,” “levator anguli oris,” and “mentalis”—deeper musculature elements—are served by cranial nerve V, the “trigeminal.” (5)
The motor nerves serving the lips come from “cranial nerve VII,” the “facial nerve.” They arise from the mandibular branch of the nerve. The sensory component of the lower lip connects to the trigeminal’s mandibular branch and travels through the mental foramen to the brainstem.(6)
There are 12 lip muscles with three serving the lower lips alone, the “depressor labii inferioris,” the “mentalis,” and the “platysma.”
The depressor labii inferioris links the mandible to the dermis and orbicularis in a fan shape, allowing the lower lip to move in and laterally.
The mentalis connects the mandible to the chin, allowing the raising of the lower lip, giving us the ability to pout. The “sheet muscle,” the platysma, connects the neck with the mandible, allowing us to depress our lower lip.(7)
Why Is Your Bottom Lip Twitching?
Locus of the Lower Lip Twitch
Our brief anatomy discussion reveals that a lower lip twitch relates to myoclonus within the depressor labii inferioris, the mentalis, the platysma, or within some combination of the three.
Alternatively, the source of the twitch may reside within the muscle’s innervation.
A Differential Approach to Identify Cause
The twitch may relate to muscle abuse, damage, fatigue, or circulation anomaly near the muscle or deep within the central nervous system.
Neurosurgeon Ravish Patwardhan notes that twitching lips are far from uncommon.(8)
Stressing muscles with overuse or pushing them to the point of fatigue may induce spasm. The VIIth nerve as it leaves the brainstem may be impacted by circulation problems, causing the twitch of the bottom lip.
The facial nerve innervation may affect the whole face with twitching in such event, inducing lip and eye spasms. Certain central events like seizures may affect those face muscles as well.
Even general well-being concerns like anxiety, relationship issues, problems with finances or work setting, etc. may set that spasm flutter in motion.
Psychosomatic Causes with Physiologic Basis
Continuous or episodic stress activates our autonomous nervous system, our internal chemical balance mechanism, and other compensation systems at both a cellular and a systems level.(9)
When we consider muscle groups impacted by stress, it is no wonder that facial myoclonus at the lower lip level may result.
Subconscious contraction of muscles in the neck, grinding of teeth with its jaw muscle action, internal muscle contraction stimulated by our “fight or flight” response to trouble in our environment—all may cause circulation anomalies at the bottom lip muscle level or at the nerve or circulation level in the neck or more centrally in our brainstem.
People get injured. Trauma has consequences, sometimes seen visibly in those black-and-blue patches on our skin, sometimes invisibly but perceived by pain, sometimes not readily measurable by testing methodology.
Motor vehicle accidents are a typical example of this kind of variability response to injury. Significant in our discussion is the implication that these kinds of trauma may induce facial tics affecting the lower lip.
But non-traumatic causes are not negated just because there is no pain. A college exam can alter those internal stress responses as readily as a MVA does in others. Unfortunately, unique events may cause long-term stress, inept coping skills, and even sequellae like tics.(10)
When lower lip quivers continue and may be worsening, a visit to your physician or a neurologist may be in order.
You can anticipate your doctor using some version of S-O-A-P, a charting system that breaks down your evaluation into modules.
These letters stand for the components of your visit, i.e., subjective, objective, assessment, and plan.
The subjective relates to your description of your tic, its history, and its symptoms.
The subjective also includes your own personal medical history (diseases, traumas, circulatory issues, etc.), your genetic data (familial data), social history impacting health (addictions, use of needles, etc.), and other relevant facts relating to your malady.
Medical school training is very specific about the need for a good history because it defines the problem.
The objective component is your physician’s physical examination.
The doc will measure your touch sensitivity and the extent of the area experiencing the tic, if it is present at the time of examination.
Given the muscular, neurological, and circulatory systems that may impact tics, your MD will want to assess muscle tone in the bottom lip, evaluate your face and neck for space occupying lesions (i.e., lumps impacting nerves or circulation), determine skeletal asymmetry in the neck region, and listen to your heart and follow arterial sounds from your neck to your lips (blood stream turbulence having relevance as to actual site of cause for the tic).
The assessment component relates to fine tuning that physical exam.
There will be lab work that may be indicated. If your physical appearance shows stress, a blood panel revealing your metabolism functioning may be appropriate to reveal anomalies or dysfunction. If your circulatory system sounds suggest underlying arterial turbulence, a blood flow study via ultrasound or radiologic procedure may be indicated.
If there is a lump, a biopsy or an MRI may be indicated to determine its extent. If there is a deviation in the neck alignment, a CT scan may enable your doc to assess pinched nerves or blood vessels.
There are other tests and evaluation procedures that may be indicated.
Your MD may do an initial assessment and recognize that you need evaluation by another kind of physician and make a referral before this further evaluation has commenced, in the middle of your lab work, or at the point your work-up has been completed.
By the time you get to this component of your doctor visit, you have gone through the first three components.
Your physician will discuss the results with you, establish a diagnosis, and together plan the next step. This plan may involve the intervention of some sort. If your metabolism is off, medications or dietary adjustment may be the result. If circulation problems are present, you may be referred to an appropriate specialist.
If you have a mass or lump, referral for further assessment may be the recommendation.
There are all kinds of recommendations that may come from a physician visit for a lip flutter. The reality of the matter is that most medical assessments for fluttering in the lower lip will be “negative,” meaning no cause for the problem has been delineated.
Advice may be simply to reduce stress in your life and return in a year or two for routine follow-up unless your symptoms change.(11)
There are causes for those three little muscles of your lower lip quivering, the vast majority of them being benign, short-lived, and related to stress in your life.
Jettison those stress red-flag factors, get in that easy-chair, put your feet up, read a book, and give up violent television.
If your problem persists, consider talking to your primary care provider and have that once-over physical exam and possible treatment or referral.
Consider looking over NINDS’ “Myoclonus Fact Sheet” for more in-depth information.