Popular Science Article | What are the manifestations of dysphagia in the oral stage? (Previous issue)

Whether we are eating or drinking, we need to swallow. The swallowing cycle is divided into the pre-oral stage, oral preparation stage, oral stage, pharyngeal stage, and esophageal stage. Some people in life have various difficulties when swallowing. Below we will start with the manifestations of swallowing disorders in the oral stage.

The organs involved in oral dysfunction include mandible, lips, tongue, soft palate and other structures. In terms of movement, lip dysfunction usually manifests as inability to close the lips, food leaking from the corners of the mouth, dysarthria and drooling; cheek dysfunction manifests as inability to puff the cheeks, inability to suck, bolus formation disorder and food residue in the mouth; tongue dysfunction manifests as bolus formation disorder, bolus propulsion disorder, swallowing with the head tilted back and premature aspiration, food retention in the mouth and swallowing in batches, dysarthria and epiglottic trough retention; masticatory muscle dysfunction manifests as difficulty chewing, bolus formation disorder and inability to open the mouth; soft palate dysfunction manifests as premature aspiration, nasal regurgitation and dysarthria.

In addition, the sensory organs are like scouts, collecting various stimuli from the world around us, and then reflecting them to our brain, which then responds to various external stimuli through commands. Therefore, sensory disorders of the lips, cheeks, tongue and oral mucosa can also cause oral stage dysfunction.

Above, we roughly gave examples of functional disorders caused by various structural disorders, but disorders of different structures may sometimes present the same or similar symptoms. Next, let’s take a closer look at the abnormal manifestations and see which structures may be the problem?

(1) Drooling

Drooling: commonly known as drooling, is a group of syndromes caused by excessive secretion of the salivary glands (salivary glands), swallowing disorders, or a combination of the two. The consequence is saliva overflowing from the corners of the mouth or frequent discomfort in swallowing and spitting out.

Drooling can be divided into physiological and pathological. We often see infants and young children drooling a lot. This is physiological. Generally, it stops by itself when the child is 15-18 months old. If it does not disappear after 4 years old, it is considered pathological drooling. Sometimes we drool while sleeping soundly. Most of them are normal phenomena, and some are related to body position. Because the muscles around the corners of the mouth are in a relaxed state during sleep, the saliva in the mouth will flow out automatically. However, if there is inexplicable drooling recently, it should be taken seriously. It cannot be ruled out that it is caused by pathological factors.

Pathological drooling is relatively complicated, and there are generally the following reasons:

Increased salivation

Saliva secretion is normal, but due to cerebral palsy, stroke, Parkinson's disease, facial palsy causing tongue muscle paralysis or facial muscle paralysis, it leads to swallowing difficulties and overflow;

Loss of sensation, especially in the front of the mouth and tongue, leads to drooling due to unawareness of saliva overflowing from the corners of the mouth and inability to swallow actively;

Psychological factors such as hysterical salivation.

(2) Articulation disorders

Dysarthria: refers to speech disorders caused by paralysis or uncoordinated movement of speech-related muscles due to damage to the nervous system. In layman's terms, dysarthria means unclear speech, unclear pronunciation and unfluent speech.

Lips, tongue, and soft palate are not only involved in chewing and swallowing, but also in pronunciation. Dysfunction of these organs can lead to articulation disorders. Weak lip muscles can affect certain pronunciations, such as the inability or unclear pronunciation of b, p, and m. The same is true for the tongue. We cannot speak without the tongue. The "three-inch indestructible tongue" vividly illustrates this point. Paralysis and inflexibility of the tongue muscles can lead to pronunciation disorders. Weakness at the root of the tongue leads to the inability or unclear pronunciation of g, k, h, etc. The soft palate is also involved in pronunciation. If the soft palate activity is weakened and cannot stick to the posterior wall of the pharynx, the nasal sound will increase when speaking, and in severe cases, the pronunciation will be difficult to understand.

(3) Difficulty opening the mouth

Stroke and tetanus can cause increased tension in the masticatory muscles. When the tension in the masticatory muscles increases, we will experience difficulty opening the mouth, the mouth opening range will decrease, affecting the delivery of food into the mouth, making eating more difficult and taking longer. In severe cases, the mouth may not open at all, the jaws may be tightly closed, and the person may not be able to eat. Abnormal function of the external laryngeal muscles can also lead to an inability to open the mouth.

(4) Inability to puff up cheeks

The cheek puffing action requires the cooperation of the lips, soft palate, tongue and cheeks. Buccinator muscle dysfunction affects the cheek puffing action.

Under normal circumstances, the buccinator muscle can pull the corners of the mouth outward and upward. If the buccinator muscle is paralyzed, it cannot pull the corners of the mouth outward and upward.

(5) Difficulty in sucking

In life, we often hear people say that someone has "gone all the way", to describe that person has tried his best. But how much "giving all the way" really means?

Some data say that the force of a baby's sucking is equivalent to a 7000Pa vacuum cleaner. Adults do not have as developed cheek muscles as babies, but the movement of cheek muscles is also a component of sucking. In life, when you use a straw to drink a cup of milk tea or suck a piece of lamb rib, you will use the sucking action. If the cheek muscles are paralyzed, it will cause difficulty in sucking.

(6) Nasal reflux

Under normal circumstances, the soft palate rises and bulges, and can be closely connected with the posterior pharyngeal wall. When the soft palate is paralyzed, the speed of the soft palate rising slows down, the lifting amplitude decreases, and the ability to rise and deform is poor.

If the soft palate cannot contact the posterior pharyngeal wall normally, the nasopharynx and oropharynx will be separated. During swallowing, if the food cannot enter the esophagus smoothly and flows back into the pharyngeal cavity, the food may be squeezed upward through the soft palate and the posterior pharyngeal wall into the nasal cavity and cause nasal reflux. This is manifested as food flowing out or spraying out of the nostrils when eating or drinking. If this happens frequently, it will lead to damage to the pharyngeal mucosa, chronic rhinitis and otitis media.

In addition, oral disorders related to eating include difficulty in chewing and food bolus formation, food bolus propulsion, food residue in the mouth, fractional swallowing, epiglottic retention, food leakage from the corners of the mouth, etc. We will continue to describe them in the next article.

Name: Huang Junni, Shanghai Pudong Hospital

Reviewer: Shen Xiafeng, Chief Physician, Director of the Rehabilitation Department of Shanghai Pudong Hospital, Standing Committee Member of the Science Popularization Working Committee of the Chinese Rehabilitation Medicine Association