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

In the previous article, we mentioned some common oral disorders. Next, there are some common disorders regarding eating, which we will continue to describe.

1. Difficulty chewing and difficulty in forming food bolus

The masticatory muscles include the masseter, temporalis, medial and lateral pterygoid muscles. Their main function is to lift the mandible and move it laterally, and to cooperate with the suprahyoid muscles to move the mandible up and down and laterally, which is beneficial for cutting and grinding food. If the masticatory muscles weaken, the ability of the oral cavity to deform during chewing will be weakened, making it difficult to place solid food during chewing, and the food cannot be effectively cut and ground. Eating fatigue is likely to occur, and a swallowable food bolus cannot be formed, so that swallowing cannot be initiated, or swallowing is delayed.

In addition to the chewing muscles, as mentioned earlier, the cheeks and tongue also play an important role in pushing food during chewing.

Therefore, dysfunction of the tongue and cheek muscles will lead to difficulty in forming a food bolus. If the cheek muscles are dysfunctional, food cannot be pushed from the oral vestibule to the oral cavity, and fingers or other tools are needed to return the food remaining in the oral vestibule to the oral cavity for further chewing. If the tongue muscles are weak, especially if the motor function of the front 2/3 of the tongue is abnormal, the tongue will lift and push the food abnormally, and the food in the mouth cannot be processed into a food bolus through chewing. If a food bolus cannot be formed, swallowing cannot be initiated in time.

2. Food Bolus Propulsion Disorder

The tongue plays a vital role in the process of pushing the food bolus forward. If the tongue muscles are weak or obviously paralyzed, the tongue moves clumsily, slowly, and with a small amplitude, and cannot shrink and deform at will, making eating extremely difficult and unable to push food to the back of the mouth and pharynx. At this time, although the tongue will move back and forth and try hard, it is all ineffective and futile.

In this case, the patient often uses compensatory postures to complete the food bolus propulsion, such as tilting the head back. In this case, since the food has gravity, the food will flow to the back of the mouth and enter the pharynx by its own gravity.

Although this method solves the problem of food entering the pharynx, it also has disadvantages, that is, the patient cannot control the time when food enters the pharynx, especially for liquid food, which has low viscosity and strong fluidity, and requires strong oral control ability. If the control ability is poor, food will flow into the pharynx before the swallowing action is started, that is, if the pharyngeal swallowing is not started in time, the consequence is premature aspiration.

3. Food residue in the mouth

The function of the buccinator muscle is to push food into the oral cavity. Its dysfunction will often result in food residue in the oral vestibule after swallowing. When the tongue muscle is weak, it cannot push the entire food bolus to the back of the oral cavity, and can only push part of the food to the pharynx. Therefore, after swallowing, there will be food left in the mouth, which is called oral food retention. If the tongue muscle on one side is weak, you can find that some food is still left in the mouth on the same side after swallowing.

4. Swallow in several times

From a health perspective, eating small meals frequently can help relieve stress, lose weight and improve your appearance, but this is not the case when it comes to "fractional swallowing". When swallowing becomes difficult and you cannot swallow food all at once, the tongue will try again to swallow the remaining food once or more before sending the food in the mouth into the pharynx. This phenomenon is called fractional swallowing.

5. Epiglottic retention

The tongue root is the main structure that pushes the food bolus into the pharynx. During the pharyngeal phase of the swallowing process, the tongue root will continue the previous oral phase action, continue to contract backward and downward, and at the same time contact the posterior pharyngeal wall that contracts forward, jointly pushing the food bolus downward and clearing the food in the vallecula epiglottis. If the tongue root is weak or the propulsion force is weakened, it can no longer push the food bolus into the pharynx, which can cause food retention in the vallecula epiglottis and prolong the pharyngeal phase.

6. Food leaks from the corners of the mouth

When patients with dysphagia eat, food sometimes leaks out of one corner of their mouth, and food will be scattered on their body or on the table, just like a child eating. This situation is more common in patients with facial paralysis, which can cause paralysis of the muscles around the mouth, such as the orbicularis oris, on one or both sides. In mild cases, the corner of the mouth droops slightly, the cheeks leak, and whistling is affected. In severe cases, the lips cannot be closed and sucking movements cannot be made. The corner of the mouth on the affected side will drool, and food will sometimes flow out of one corner of the mouth. If facial paralysis occurs on both sides, the closed mouth cannot be maintained due to weak bilateral facial muscles. The mouth is usually open and drooling. The lips cannot be closed during chewing and swallowing. When food is squeezed in the oral cavity, some food leaks out from between the lips, significantly affecting swallowing efficiency.

In daily life, when the obstacles we mentioned exist, we should seek medical treatment and rehabilitation as soon as possible so that we can better devote ourselves to life.

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