Teeth that grind at night as if they had their own will or that clench during the day without realizing it, tense jaws without knowing why... These unconscious movements are a disorder called bruxism, as well as being clear symptoms of stress or anxiety, and usually have consequences not only for the teeth. Although some recent studies indicate that they can also be alerts that prevent worse evils.
Bruxism has increased remarkably in recent years. The General Council of Dentists of Spain confirms in the 2023 White Paper the growth of this problem in the country: it has gone from 6% in 2019 to 23% at present, and this increase is attributed to the pandemic, which aggravated anxiety and stress among the population. And although clenching can be normal to a certain point, when it affects the quality of life causing a series of discomforts, it must be monitored and consult with the experts.
But what exactly is bruxism? As Óscar Castro Reino, president of the General Council of Dentists of Spain, explains, it is a dysfunction of the temporomandibular joint (TMJ), which is located between the temporal bone and the jaw, allowing jaw dynamics. This articulation is important for the functions of chewing, swallowing and phonation. This disorder can occur both day and night. "The daytime type is related to external stimuli of a psychosocial or environmental type, while the nocturnal type is muscular, which causes jaw movements and teeth grinding during sleep hours with an involuntary rhythm," Castro details.
Rather than talk about daytime or nighttime, other specialists such as Eva Willaert Jiménez-Pajarero, a doctor in dentistry, prefer to classify it as wakefulness or sleep bruxism. "Wakefulness would be the one in which we are awake, we clench our teeth and we only realize it until something hurts, it would be like when you have a bad posture on the computer, you don't realize it until the pain warns you", In contrast, "in sleep bruxism what we do is clench or grind our teeth, that is, a repetitive activity while we sleep, even if we do it during the day," says Willaert, who is also an associate professor of prosthetics and Craniomandibular Dysfunction at the University of Barcelona (UB).
Of course, sleep bruxism and wakefulness can also appear in many people together, which is called comorbidity. In other words, it is possible to have both disorders at the same time, although studies have not been able to determine if one is a risk factor for the other. However, it should be noted that they are two different entities that can be treated independently, Willaert clarifies.
“The most frequent causes of bruxism are stress and tension, but there are other reasons that can cause it, such as malocclusion, skeletal asymmetry, arthritis, or degenerative and inflammatory disorder of the temporomandibular joints,” says Castro.
Several recent investigations have provided new perspectives on bruxism. In a recent study from the Complutense University of Madrid, carried out before, during and after the pandemic, it was concluded that the different states of anxiety influenced the type of bruxism. Thus, wakefulness was more closely linked to immediate daytime activity, while sleep bruxism was more closely related to passive stress.
Another study reported by The New York Times, citing the American Dental Association (ADA) as a source, stressed that stress caused overproduction of stomach acid and reflux, and encouraged more alcohol drinking, which relaxes neck muscles These three would be factors that favor bruxism.
The change of perspective proposed by these investigations even goes so far as to suggest that bruxism could have some positive aspect. On the one hand, it could be an escape mechanism from stress when you are awake. And on the other, it could somehow protect against gastric reflux and obstructive sleep apnea. "Perhaps bruxism is serving as a protective factor, that is, if the apnea is a lack of air passage, a collapse of the pathway through the tongue while you sleep, one of the hypotheses is that bruxism serves to activate the muscles and open the via,” says Willaert.
The relationship between stress and anxiety with waking bruxism is unquestionable and numerous studies have shown this, comments Castro. "These investigations logically escape the purely dental field, but in any case, whether or not it is a stress escape mechanism, it seems obvious that it causes unhealthy effects on oral health," Castro points out.
It should also be noted that today bruxism is considered one of the sleep disorders, adds Castro. According to the specialist, to find out the origin and degree of severity of this pathology, you should go to the dentist at the first symptoms, which are usually headache and neck pain, discomfort in the muscles of the face, dental wear and clicking when opening Or shut your mouth. "It is vitally important to know how to treat bruxism in order to improve the patient's quality of life and avoid major problems," warns Castro.
“However, it is normal to grind your teeth. And what does this mean? Well, there may be people who do it and do not suffer from bruxism since this activity is common every night, ”says Willaert. Because, contrary to popular belief, teeth grinding doesn't happen while you're dreaming. Studies on sleep indicate that these episodes occur during the non-REM phase, where there is muscular activity, in which at times what we call microarousals occurs, where there is cerebral, muscular and cardiorespiratory activation and a last event of muscular activity that sometimes it is accompanied by dental contact, sometimes not, Willaert details
Normally, the person who 'bruxes' has these rhythmic episodes more frequently, which occur during the non-REM phase and which are called AMMR (Rhythmic Masticatory Muscular Activity), as described by Willaert. “The frequency of these episodes, according to sleep medicine studies, indicates that two or three per hour are normal, but if there are more than four it is when what we popularly call teeth grinding appears or is heard. We are currently doing studies at the university with 21-year-old students and there are people who even do up to eight episodes”, concludes Eva Willaert, who is also an expert in dental sleep medicine, certified by the Spanish Federation of Sleep Medicine Societies. Dream (Fesmes).
It has not been possible to determine, however, a correlation between a greater number of episodes and more pain or more problems. "Bruxism is not the same in all individuals, there are people who have a high index during the night and the next day they don't even notice and it doesn't hurt at all, but there are others who have muscle pain, worn or broken teeth, tongues that appear with slits to squeeze them and even implants that loosen even when well made, Willaert argues. "When a person has episodes and it does not imply any alteration in their quality of life, it does not represent a problem - continues the expert - but when it is causing jaw pain, sleep disorders, they wake up crushed or with a headache, they have to worry about looking at it and correct it."
The main risks of untreated bruxism are, on the one hand, dental wear (due to attrition of the teeth) that leads to a loss of enamel and dentin, with the subsequent appearance of dental sensitivity. And, on the other hand, the appearance of disorders in the temporomandibular joint with the possible presence of pain, clicks and even limitation of the opening of the mouth, warns Óscar Castro.
As Castro explains, treatment is usually multidisciplinary and may include neuromuscular dentistry, physiotherapy, treatment of possible malocclusions and the use of splints, in addition to prior treatment of possible carious lesions or missing teeth. “In some cases, drugs are used both to treat anxiety and inflammation of the joint, as well as relaxation techniques, stress control and physiotherapy. Surgery is only recommended in extreme cases”, qualifies the president of the General Council of Dentists of Spain.
It is relatively frequent that it is necessary to resort to combined treatments, both of a purely dental nature (splints, rehabilitation, orthodontics, etc.) and interdisciplinary with the intervention of other professionals (experts in sleep medicine, physiotherapists, psychologists, etc.). Determining the cause that produces it is key to correcting it in the medium term, emphasizes Castro.
Eva Willaert warns that it should be taken into account that bruxism is not a disease but a pathology, like fever, for example, and since it can have more than one cause, it will be necessary to investigate it. “You cannot apply orthodontic treatment just because someone tells us that they grind their teeth; Individuals with a perfect mouth can still clench or grind their teeth because the switch is in our brain and we cannot tell someone that by changing their bite they will stop doing it”, clarifies the dentist.
According to Willaert, bruxism is like the tip of the iceberg. The American Association for Dental Sleep Medicine recommends inquiring about the frequency of grinding, signs of wear or damage, dietary factors or dental erosion (such as the consumption of carbonated drinks) or habits such as the consumption of tobacco, alcohol or drugs of synthesis. Each case is different. According to their data, sleep bruxism usually occurs in 14-18% of children and adolescents, 8-10% in adults, and only 3% over 50 years of age.
