"Corn kernels" grow in the mouth, and they smell bad when you squeeze them. What are they?

Some people spit out or cough up yellowish-white objects that look like millet grains and smell bad when they cough, swallow, or sneeze.

Some people come to the doctor because of throat discomfort. During the examination, yellow-white irregular objects can be seen stuck in the tonsils.

Tonsil stones before and after falling off

In either case, the yellow-white objects mentioned above are most likely " tonsil stones ".

Some people may even experience a foreign body sensation in the throat or more severe discomfort in the throat because the substance remains stuck in the tonsils.

As the name suggests, tonsil stones are stone-like substances formed in the tonsils . The "tonsils" we often refer to are usually the palatine tonsils, which are the two lumps of tissue on both sides of the uvula that can often be seen when you open your mouth.

Tonsils diagram

Although there are cases of tonsil stones in pharyngeal tonsils (referring to adenoids) and lingual tonsils, the vast majority of tonsil stones occur in the palatine tonsils (hereinafter referred to as tonsils).

Causes of tonsil stones

It is generally believed that the formation of tonsil stones is related to chronic inflammation of the tonsils.

At present, the specific mechanism of tonsil stone formation has not been confirmed, but it may be related to the following points:

1 The structure and function of tonsils

Tonsils are a healthy line of defense in the throat. They are lymphoepithelial organs composed of a tight connection between lymphatic tissue and epithelium.

The surface of tonsils is not smooth. On the contrary, in order to be exposed to as many pathogens as possible and form immune memory, the tonsil epithelium chooses to fold in a limited space and sink into the tonsil parenchyma, forming "tonsil crypts" of varying depths.

Each adult's palatine tonsil has an average of 10-20 crypts, as shown in the following figure:

Palatine tonsil anatomy

This allows the cell to more effectively contact pathogens and present antigens to immune cells per unit volume, while also helping immune cells that have already formed memory to kill pathogens.

However, this also creates the conditions for the formation of tonsil stones:

When the crypt opening is enlarged, food debris can fall into the crypt opening;

When the pathogen load and virulence exceed the body's load, it will cause tonsil infection or chronic tonsil inflammation;

Tonsillar crypts are anaerobic environments, which are conducive to the growth of anaerobic bacteria.

2. Garbage accumulation

Food residues, bacteria, clumps formed by metabolic products and purulent secretions (including immune cells), desquamated cells and calcium salts secreted by glands that fall into the crypts will continue to wrap and deposit, forming stone-like cheesy substances that gradually increase in size and are discharged to the crypt openings.

3 Biofilm formation

In addition, some bacteria can transform from a free state to a biofilm state to form bacterial biofilms.

Biofilms have very high resistance, which can help stones resist drugs and escape the immune attack of tonsils, allowing them to colonize in the tonsil epithelial layer for a long time, repeatedly inducing inflammation, thereby aggravating the obstruction of the crypts and promoting the formation of stones.

Are tonsil stones common?

The answer is yes, but most people have no symptoms.

Several retrospective analyses have evaluated the incidence of tonsil stones in Asian populations: ranging from 30.3% to 46.1%.

In addition, epidemiological results show that although tonsil stones can occur in people of all ages, the majority of them occur in adults.

According to the current large-scale CT imaging tests, the prevalence of tonsil stones in men is higher than that in women, and the probability of developing tonsil stones increases accordingly with increasing age.

Symptoms of tonsil stones

Because of the location of the tonsils, most of the symptoms caused by tonsil stones are related to pharyngeal sensation and swallowing function.

Small tonsil stones do not cause symptoms, but as tonsil stones grow larger and pass out of the crypts, they may cause the following symptoms:

Foreign body sensation in the throat

Pain (direct irritation from tonsil stones)

Ear pain (radiating pain to the glossopharyngeal nerve)

Dysphagia (pharyngeal motor traction)

Bad breath

Because tonsil stones usually contain bacteria and their products, they may have a special odor. This is why some people still have bad breath even if they pay great attention to oral hygiene.

The above symptoms may be relieved after the tonsil stones fall off, but they will reappear as new tonsil stones are formed and expelled.

Treatment of tonsil stones

1What can we do ourselves?

As mentioned before, tonsil stones are located in the tonsillar crypts, so the most direct and effective treatment method is manual cleaning.

Measures that can be taken include squeezing, grasping, and flushing (forced cleaning is not recommended if there is no obvious sign of outward migration). If the tonsil stones can be discharged smoothly, the symptoms can be effectively relieved.

In addition, improving oral hygiene such as rinsing your mouth after meals and brushing your teeth carefully may help reduce the occurrence of tonsil stones.

2 Medical treatment methods

Because the stones originate from the tonsillar crypts, there are some reports of using CO2 laser ablation, thermodynamic destruction (plasma) and other methods to open the tonsillar crypts in order to reduce the formation of tonsillar stones. Small-scale studies have shown that this method is effective.

Laser ablation for tonsil stones

However, due to the limited concentration of antibiotics reaching the tonsil epithelium, the strong resistance of biofilm bacteria to antibiotics, and the unknown species of colonizing bacteria, antibiotics are generally not recommended for the treatment of tonsil stones.

In addition, although tonsillar crypt stones are a rare cause of bad breath, tonsillectomy surgery may be considered for those who have obvious and persistent bad breath after other possible causes such as oral hygiene and dental health have been ruled out and have been adequately treated by self-cleaning of the tonsillar crypts.

References

[1]Niedzielski A, Chmielik LP, Mielnik-Niedzielska G, et al. Adenoid hypertrophy in children: a narrative review of pathogenesis and clinical relevance. BMJ Paediatr Open. 2023 Apr;7(1):e001710. doi: 10.1136/bmjpo-2022-001710. PMID: 37045541; PMCID: PMC10106074.

[2]BuSaba, N. & Doron, S. (2021). Tonsillectomy in adults: Indications. Uptodate.

[3]Kim, MJ, et al., Multidetector computed tomography imaging characteristics of asymptomatic palatine tonsilloliths: a retrospective study on 3886 examinations. Oral Surg Oral Med Oral Pathol Oral Radiol, 2018. 125(6): p. 693-698.

[4]Takahashi, A., et al., Prevalence and imaging characteristics of palatine tonsilloliths evaluated on 2244 pairs of panoramic radiographs and CT images. Clin Oral Investig, 2017. 21(1): p. 85-91.

[5]Oda, M., et al., Prevalence and imaging characteristics of detectable tonsilloliths on 482 pairs of consecutive CT and panoramic radiographs. BMC Oral Health, 2013. 13: p. 54.

[6]Krespi, YP and V. Kizhner, Laser tonsil cryptolysis: in-office 500 cases review. Am J Otolaryngol, 2013. 34(5): p. 420-4.

[7]Ferguson, M., M. Aydin, and J. Mickel, Halitosis and the tonsils: a review of management. Otolaryngol Head Neck Surg, 2014. 151(4): p. 567-74.

Planning and production

Source: Yihe Science

Author: Dr. Chen Shan, an otolaryngologist

Editor: He Tong