Why do older people chew with their mouth open? Understanding the causes

As people age, many experience physiological changes that can affect eating habits. To understand why do older people chew with their mouth open, one must explore factors ranging from dental issues to neurological conditions, a common concern in senior care. This guide provides a compassionate and comprehensive overview of the contributing factors.

Quick Summary

This behavior is often linked to age-related changes like weakened facial muscles, ill-fitting dentures, dry mouth, or compromised nerve function. Underlying health issues, including some forms of dementia and certain medication side effects, can also contribute to this eating pattern.

Key Points

• Muscle Weakness: Weakening of facial muscles, including those controlling the lips, can make it difficult to keep the mouth closed during chewing.

• Dental Issues: Poorly fitting dentures or natural tooth loss can cause discomfort or instability, leading an older person to chew with their mouth open.

• Neurological Conditions: Disorders like tardive dyskinesia, a side effect of some medications, and cognitive decline from dementia can cause involuntary chewing motions.

• Sensory Decline: A diminished sense of smell and taste may cause an older person to chew with their mouth open to get more aromatic feedback from their food.

• Airway Restriction: Chronic mouth breathing due to respiratory problems can carry over into eating, making it difficult to close the mouth while chewing.

• Loss of Proprioception: The body's sense of its position can decline with age, meaning an older person may not be consciously aware that their mouth is open while eating.

Unpacking the Physiological Reasons

Observing an older adult chewing with their mouth open can be confusing or even frustrating for family members. However, this behavior is rarely a sign of disrespect or forgetfulness. Instead, it is often a symptom of underlying physiological changes related to the aging process. These changes can affect the muscles, senses, and neurological pathways responsible for coordinated chewing and swallowing.

The Impact of Dental and Oral Health Changes

Oral health is a significant factor in how a person chews. Over time, several issues can alter eating mechanics:

• Tooth Loss and Dentures: The loss of natural teeth is common among seniors. Dentures, while a great solution, are not always a perfect fit. Poorly fitting dentures can shift during chewing, causing discomfort or instability. This may cause an older person to keep their mouth slightly open to adjust the positioning or to avoid irritation.
• Weakened Facial Muscles: Just like other muscles in the body, the muscles used for chewing and jaw control weaken with age. The orbicularis oris muscle, which controls the lips, can lose tone, making it difficult to maintain a tight seal around the mouth while eating. This involuntary muscle weakening is a key reason for open-mouth chewing.
• Dry Mouth (Xerostomia): A decrease in saliva production, often a side effect of medication, can lead to dry mouth. Saliva plays a crucial role in lubricating food and assisting with swallowing. When the mouth is dry, an individual may chew with their mouth open to help introduce air, moisten the food, and facilitate the chewing process.

Neurological Factors and Sensory Decline

Beyond the physical structure of the mouth, the brain's ability to coordinate and process sensory information during eating can change with age.

• Diminished Proprioception: Proprioception is the sense of knowing where your body parts are in space without looking. As this sense declines, older adults may lose the intuitive feedback that tells them their mouth is open or that their lips need to be sealed during chewing. They may not be consciously aware they are doing it.
• Tardive Dyskinesia: This is a neurological disorder characterized by involuntary, repetitive body movements. It is a potential side effect of long-term use of certain antipsychotic medications. Tardive dyskinesia can cause involuntary movements of the jaw, lips, and tongue, which can directly lead to open-mouth chewing or repetitive smacking noises.
• Dementia and Cognitive Decline: For individuals with dementia, the simple act of eating can become a complex and confusing task. They may forget the social etiquette of closing one's mouth or lose the motor control needed to keep it closed. This is a form of perseveration, a symptom where a person gets stuck on a repetitive action or movement. Caregivers often need to gently remind the person to close their mouth.

Airway and Respiratory Issues

Some older adults may be mouth breathers due to chronic nasal congestion, enlarged adenoids, or other respiratory conditions. If breathing through the nose is difficult, a person will naturally breathe through their mouth. This can be difficult to turn off while eating, resulting in continuous mouth breathing and open-mouth chewing.

Compensating for Sensory Loss

For some, chewing with an open mouth is an unconscious attempt to enhance the dining experience. Both taste and smell diminish with age, and chewing with the mouth open can allow more food aromas to reach the nasal passages, boosting the overall flavor perception. It's a compensatory mechanism for a weakened sense of smell.

Comparison: Normal Aging vs. Clinical Concerns

This table helps distinguish between typical age-related changes and signs that might require a professional evaluation.

Attribute	Normal Aging Variation	Potential Clinical Concern
Chewing Action	Slower, more deliberate chewing; occasional open mouth.	Persistent, involuntary chewing motions (even without food); inability to close the mouth.
Lip Control	Lips may not seal perfectly due to muscle laxity.	Constant lip smacking, puckering, or involuntary movements.
Dentures	Minor adjustments for comfort.	Frequent complaints of ill-fitting or painful dentures; difficulty wearing them.
Cognition	Some mild forgetfulness.	Forgetting how to chew or swallow; inability to respond to reminders to close the mouth.
Awareness	Can correct behavior when gently reminded.	No response or comprehension when reminded; no apparent awareness of the behavior.

Addressing the Issue with Compassion

When an older person chews with their mouth open, the best approach is to act with empathy and patience. Rather than reprimanding them, consider these steps:

1. Check for Discomfort: First, evaluate if the behavior is caused by pain. Ask about their dental comfort. An appointment with a dentist may be necessary to check denture fit or address any underlying issues. A dry mouth can also be very uncomfortable; offering sips of water can help.
2. Use Positive Reinforcement: Instead of saying, “Don't chew with your mouth open,” try a gentle, positive reminder like, “Let's remember to keep our lips closed while eating.” This is less confrontational and more effective.
3. Adjust the Dining Environment: Ensure the dining area is calm and free from distractions. A stressful or overstimulating environment can exacerbate cognitive issues and make concentration difficult.
4. Consult a Professional: If the behavior is new, worsening, or accompanied by other involuntary movements, a visit to a doctor is warranted. This could be a sign of a neurological issue like tardive dyskinesia or a progression of a condition like dementia.
5. Address Sensory Needs: Offering foods with stronger, more distinct flavors might satisfy the urge to seek sensory input through open-mouth chewing. Also, ensure a person is not eating so quickly that they forget proper chewing etiquette.

The Role of Awareness

It's important to recognize that an older person may simply be unaware of their actions. The ability to monitor one's own body movements can decrease with age, particularly if cognitive function is declining. In these cases, the behavior is not a choice but an involuntary physiological response. Understanding this helps caregivers and family members approach the situation with greater patience and less judgment.

For more information on the impact of aging on sensory function, consult reliable health resources such as the National Institutes of Health. They offer extensive studies and reports on the topic. By understanding the root causes and approaching the situation with compassion, we can ensure that dining remains a pleasant and dignified experience for everyone involved. Addressing the core medical issue is always the first step, so be sure to consult a healthcare professional for a proper diagnosis and care plan.

Frequently Asked Questions

Is open-mouth chewing a sign of dementia in older adults?

While not a definitive sign, open-mouth chewing can sometimes be a symptom of dementia. In individuals with cognitive decline, the ability to control facial muscles and remember social etiquette can be affected. However, it is one of many potential causes and should be evaluated in context with other symptoms.

Can ill-fitting dentures cause older people to chew with their mouth open?

Yes, ill-fitting or uncomfortable dentures are a common cause. If dentures are loose or cause pain, an older person may keep their mouth slightly open to minimize movement and irritation, or to adjust the position of the dentures while chewing.

What is tardive dyskinesia and how does it relate to open-mouth chewing?

Tardive dyskinesia is a neurological disorder causing involuntary, repetitive movements. It can affect the facial muscles, causing involuntary chewing, lip smacking, or tongue movements. It is often a side effect of long-term use of certain antipsychotic medications and can cause open-mouth chewing.

Does a dry mouth contribute to open-mouth chewing in seniors?

Yes, dry mouth, or xerostomia, can be a contributing factor. A lack of saliva makes it harder to break down food. Some older adults may chew with their mouth open to help introduce air and moisten the food, making it easier to swallow.

How should a caregiver address open-mouth chewing with an older adult?

Address the issue with compassion, not confrontation. Try a gentle, positive reminder like, "Let's remember to close our lips." Focus on identifying the underlying cause, such as checking for dental pain or dry mouth, and consult a doctor if the behavior is new or worsening.

Can a loss of taste and smell cause someone to chew with their mouth open?

Yes, a diminished sense of taste and smell is common with age. By chewing with an open mouth, an older person can allow more food aromas to reach their nasal passages, unconsciously trying to enhance their sensory experience and make their food more flavorful.

Is it possible for older people to simply be unaware they are chewing with their mouth open?

Absolutely. A decline in proprioception, the sense of body position, can cause an older person to lose the subconscious awareness of their mouth being open. They may genuinely not realize they are doing it, especially if also experiencing some cognitive decline.