Causes of Constant Mouth Smacking in Older Adults
Observing repetitive mouth movements in an elderly loved one can be unsettling. While it might be an unconscious habit, it's often a sign of an underlying medical issue that requires attention. Constant lip smacking, chewing, or puckering could stem from various physical, neurological, or dental causes, which are frequently more prevalent in older age.
Tardive Dyskinesia: A Medication-Induced Condition
Tardive Dyskinesia (TD) is one of the most well-documented causes of involuntary facial and oral movements. It is a neurological syndrome that develops as a side effect of long-term use of certain medications, particularly older antipsychotic (neuroleptic) drugs. While newer, 'atypical' antipsychotics carry a lower risk, they don't completely eliminate it. Other medications, including some used for nausea, mood stabilization, and depression, can also trigger TD.
Symptoms of TD can develop months or even years after starting a medication and can include:
- Lip smacking or puckering
- Chewing motions
- Tongue protrusion or thrusting
- Rapid eye blinking
- Grimacing
- Puffing cheeks
Older adults are particularly vulnerable to developing TD, even at lower medication dosages, due to age-related changes in the brain's dopamine pathways. TD can be particularly distressing as the movements are often irreversible, though early intervention can sometimes lead to improvement.
Dental Problems and Oral Discomfort
For many seniors, oral health issues are a direct contributor to repetitive mouth behaviors. Ill-fitting or uncomfortable dentures are a frequent culprit, as the person might unconsciously smack their mouth to adjust the appliance or alleviate discomfort. A visit to the dentist to have dentures properly fitted is a straightforward solution that can offer significant relief.
Beyond dentures, other dental issues can play a role:
- Missing Teeth: The absence of teeth can cause the mouth and facial muscles to weaken, leading to involuntary movements in an attempt to maintain muscle activity.
- Dry Mouth (Xerostomia): A very common problem in older adults, often caused by medication side effects (over 400 medications list dry mouth as a side effect), dehydration, or medical conditions like diabetes. Without enough saliva, the mouth can feel sticky, prompting the person to smack their lips to generate moisture. Chewing sugar-free gum or sucking on sugar-free candies can sometimes help stimulate saliva flow.
Neurological and Cognitive Disorders
Several neurological conditions can manifest with involuntary oral movements, including:
- Parkinson's Disease: This progressive disorder affects movement control and can cause facial tremors, including repetitive jaw and lip movements. The primary medication used to treat Parkinson's, levodopa, can also cause dyskinesia as a side effect.
- Dementia: As cognitive function declines, individuals with dementia may exhibit repetitive behaviors known as perseveration. In the case of Frontotemporal Dementia (FTD), compulsive actions like lip smacking can become common. Involuntary chewing motions, sometimes called 'geriatric chewing,' can also be a symptom of later-stage dementia.
- Meige Syndrome: A type of focal dystonia that involves involuntary muscle contractions of the jaw, tongue, and eyelids. This can cause jaw thrusting, grimacing, and other oral spasms.
Other Contributing Factors
In addition to the primary causes, other factors can exacerbate or contribute to the problem:
- Stress and Anxiety: High stress levels can worsen many involuntary movement disorders. For individuals with conditions like TD or Meige syndrome, anxiety can trigger or intensify symptoms.
- Substance Abuse History: Older adults with a history of alcohol or substance abuse may have an increased risk of developing movement disorders like TD.
Comparison of Causes for Oral Dyskinesia
Understanding the subtle differences between potential causes is crucial for accurate diagnosis. A clinician will use this information, along with patient history, to differentiate between conditions.
| Feature | Tardive Dyskinesia (TD) | Dental Issues (Dentures, Dry Mouth) | Neurological Disorders (Parkinson's, Dementia) |
|---|---|---|---|
| Primary Cause | Long-term use of dopamine-blocking medication (antipsychotics, anti-nausea) | Poorly-fitting dentures, missing teeth, or inadequate saliva | Neurodegeneration in the brain affecting movement control (Parkinson's) or cognitive function (Dementia) |
| Movement Type | Involuntary, repetitive, irregular movements like chewing, smacking, puckering | Often a conscious or semi-conscious adjustment for comfort, or a reaction to dryness | Parkinson's: Resting tremors or stiffness. Dementia: Repetitive, purposeless actions (perseveration) |
| Onset | Often delayed; develops months or years after medication use begins | Onset can be sudden, related to recent dental work or changes in health status | Gradual and progressive, associated with the natural course of the disease |
| Associated Symptoms | Can include tremors in limbs, fidgeting, restlessness | Discomfort while chewing, oral sores, difficulty swallowing | Tremors, rigidity, balance issues (Parkinson's). Memory loss, behavioral changes (Dementia) |
| Medical Intervention | Medication adjustment or VMAT2 inhibitors. | Dentist visit for refitting/repair or treatment of dry mouth. | Management of underlying condition, possibly with medication. |
What to Do If You Notice Repetitive Mouth Smacking
If you are caring for an elderly person exhibiting this behavior, it's important to approach the situation with patience and a calm demeanor. The movements are not something they can easily control. Here are some constructive steps to take:
- Consult a Doctor: Schedule an appointment with a healthcare professional, preferably a neurologist or a general practitioner familiar with geriatric care. Provide a detailed list of medications the person is taking, including over-the-counter drugs, as well as any existing health conditions.
- Conduct a Dental Check-Up: Visit a dentist to rule out or address any oral issues. The dentist can check the fit of dentures, assess for dry mouth, and examine overall oral health.
- Document the Movements: Keep a diary noting when the movements occur, what they look like, and if any specific activities or medications seem to trigger them. You can also discreetly record a video to show the doctor, as symptoms can sometimes be intermittent.
- Offer Hydration and Saliva Stimulation: If dry mouth is a factor, encourage frequent sips of water or offer sugar-free gums or lozenges to stimulate saliva production.
- Focus on Comfort and Support: Realize the person may be embarrassed or unaware of the movements. Offer reassurance and maintain a supportive, low-stress environment. Reducing stress can help manage symptoms. For more information on caring for a loved one with TD, visit the WebMD resource on Tardive Dyskinesia.
Conclusion
Constant mouth smacking in an older person is a symptom, not a condition in itself, with several potential root causes. While it can be a side effect of necessary medications like antipsychotics (Tardive Dyskinesia), it can also be linked to straightforward dental problems like ill-fitting dentures or dry mouth. Other possibilities include underlying neurological disorders such as Parkinson's or dementia. Regardless of the cause, a thorough medical evaluation is the first and most critical step. Early detection and proper management are key to improving the person's comfort and overall quality of life. By staying informed and communicating effectively with healthcare professionals, caregivers can play a vital role in addressing this sensitive issue.
