A pattern has been identified linking joint and muscle complications to periodontitis.

Periodontitis is the inflammation of the tissues surrounding the tooth, which leads to the destruction of the tooth's ligaments and the bone tissue of the jaw. If left untreated, periodontitis can result in tooth loss and disrupt the integrity of the dental arch. According to data from the World Health Organization as of November 2024, in 194 countries worldwide, the prevalence of periodontal diseases among the adult population exceeds 51 percent. Approximately 19 percent of the global adult population suffers from periodontitis, amounting to over one billion cases worldwide.

— According to forecasts from our research group, by 2050 more than one and a half billion people will suffer from generalized periodontitis, which is an increase of 44.32 percent compared to 2024, — explained Elena Bulycheva, head of the Department of Continuing Education for Dental Specialties at NovSU. — More than 660 million will experience partial or complete tooth loss, which is an increase of 84.40 percent compared to now.

The etiology of periodontitis involves the interaction of microbiological, local, immune, and genetic factors. A central role in the pathogenesis of the disease is played by the disruption of the oral microbiome, as demonstrated by numerous studies. The disease is caused by an increase in the number of bacteria such as Porphyromonas gingivalis, Tannerella forsythia, Aggregatibacter actinomycetemcommitans, and others.

— When teeth are lost, changes in the tilt and shortening of teeth occur, which creates excessive traumatic pressure on the surrounding tissues, — said Elena Bulycheva. — Computer tomography data show that there is destruction of the jawbone, exacerbating the course of the disease.

The study also involved medical doctors, professors from the First Saint Petersburg State Medical University named after Academician Pavlov, Vladimir Trezubov, Roman Rozov, as well as PhD Darja Bulycheva, PhD Irina Naidanova from the Chita State Medical Academy, PhD Natalia Shevkunova from the Izhevsk State Medical Academy, and dentist Eldar Valeev from the Gulliver dental clinic in Ufa.

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The experimental group consisted of 675 individuals aged 37 to 64 with generalized periodontitis of moderate to severe severity. The control group included 54 individuals aged 28 to 36 with mild periodontitis. The study employed both clinical methods – surveys, examinations, palpation, auscultation (listening), and paraclinical methods – computer tomography, muscle bioelectrical activity studies, and others.

Results from the experimental group indicated the development of functional disorders in the masticatory muscles. In periodontitis, the perception of inter-tooth contact force decreases, which reflexively provokes an increase in muscle tone. Moreover, over time, the degree of tooth mobility worsens, forming blocks between them, which necessitates changes in the trajectory of lower jaw movements.

As a result, functional disorders develop first, followed by morphological changes in the masticatory muscles and the temporomandibular joint. This fact led to the implementation of a comprehensive approach for relaxing the masticatory muscles: 64.9 percent of patients were prescribed injections of botulinum toxin, while 35.1 percent of patients who declined received Sirdalud (a muscle relaxant that affects the function of skeletal muscles and reduces muscle tone).

— In our study, we identified muscle and joint complications in patients with moderate or severe periodontitis, — explained Elena Bulycheva. — Pathological changes in the masticatory muscles manifested as disruption of their function – non-productive activities not related to natural acts of chewing, swallowing, or speaking. Different clinical forms were noted: teeth clenching – 35.9 percent of patients, teeth grinding (bruxism) – 62.8 percent of patients, non-food chewing (bruxomania) – 1.3 percent of patients.

The leading symptom is spasm of the masticatory muscles; additionally, the following manifestations may occur: pain and rapid muscle fatigue, more frequently in the morning, teeth grinding during sleep, clenching teeth during the day under physical or emotional stress, decreased work capacity, headaches, dizziness, and sleep disturbances.

As the researcher notes, joint complications developed following functional disorders of the muscle complex: temporomandibular joint pain dysfunction syndrome (a complex of symptoms including pain and clicking in the joint, along with tinnitus and headaches) – 52.4 percent of patients, "clicking" jaw – 29.3 percent of patients, and arthrosis (a joint disease characterized by the destruction of intra-articular cartilage) of the temporomandibular joint – 18.3 percent of patients.

Additional Measures

The study also revealed changes in immune status – differences in the levels of immune proteins in the oral cavity between the experimental and control groups. Patients with moderate and severe periodontitis showed increased levels of inflammatory proteins – IL-1β and INF-γ – and decreased concentrations of anti-inflammatory proteins IL-4 compared to patients with mild periodontitis. Additionally, the experimental group had reduced immunoglobulins – sIgA and IgM – and increased IgA levels.

— These data suggest that the local immunity in the oral cavity of the experimental group patients is reduced, which contributes to a more severe course of periodontitis, — explained Elena Bulycheva. — It is important to prescribe immunomodulators and antioxidants to such patients to restore immunity and ensure the most effective treatment of periodontitis. We prescribed immune stimulants such as Taktyvin, Betaleikin, and Bestim.

The proposed additional therapeutic measures allow for more effective treatment of periodontitis and better prepare patients for dental prosthetics.

The findings of the study laid the groundwork for clinical recommendations on "Treatment of Patients with Diseases of the Temporomandibular Joint and Masticatory Muscles," which outline the clinical picture, diagnostics, and medical tactics for alleviating muscle and joint complications in moderate and severe periodontitis. These clinical recommendations are the first of their kind in Russia.

The scientific discovery can be utilized by orthodontists, general dentists, and dental practitioners for planning medical tactics in patients with chronic generalized periodontitis of moderate and severe severity (decompensated dental arches) who have joint and muscle complications.

Currently, the discovery is being applied in dental clinics in Veliky Novgorod, Saint Petersburg, Ufa, and other cities, and is also included in the lecture and practical materials for dental specialties in the residency and specialization programs at Novgorod State University and the First Saint Petersburg State Medical University named after Academician Pavlov.

The authors of the scientific discovery have been awarded a diploma from the International Academy of Authors of Scientific Discoveries and Inventions. Based on a decision from the Presidium of the Russian Academy of Natural Sciences, the authors were honored with the Ivan Pavlov Medal for their contribution to the development of medicine and healthcare.