Acta Universitatis Dentistriae et Chirurgiae Maxillofacialis

Partial tooth loss and dentition defects result from dental caries and its complications, as well as periodontal diseases, and are among the most prevalent dental conditions in Russia and worldwide. These conditions impair all functions of the dentoalveolar system and lead to a range of physical and psychological complications. When addressing dentition defects, one of the treatment options may be a properly fabricated removable partial denture, as well as a combined removable prosthesis with attachment systems. Such a design is particularly relevant for patients who seek to obtain a functional and esthetic dental prosthesis with reliable fixation and for whom treatment involving dental implants is not feasible due to anatomical features, general health status, financial limitations, or psychological considerations. Combined removable dentures with precision attachments demonstrate the most favorable outcomes in the prosthetic rehabilitation of dentition defects. These designs provide minimal invasiveness and reversibility of treatment, enable physiological redistribution of masticatory load between abutment teeth and the oral mucosa, unite preserved teeth into a single functional system, restore masticatory and speech function, and exhibit high esthetic performance along with other substantial advantages. At the same time, achieving optimal retention remains a key requirement for long-term and comfortable use of prosthetic constructions. The type of retention element plays a decisive role in ensuring prosthesis stability; therefore, the development of new fixation methods for combined removable prostheses remains a relevant challenge.

Clinical studies by Russian and international authors demonstrate that temporomandibular joint disorders and masticatory muscle dysfunction represent common dental condition. A distinct nosological entity among temporomandibular joint disorders is forced mandibular position syndrome, a pathological condition characterized by compensatory or non-physiological displacement of the mandible. The clinical presentation of this syndrome is polymorphic and includes a complex of specific clinical and paraclinical signs, such as myoarticular dysfunction, occlusal disturbances, pain in the temporomandibular joint region, and other impairments of the masticatory and speech apparatus. A key component of rehabilitation in this condition is verification of the vector of mandibular displacement followed by registration of the centric relation. Successful completion of this stage establishes the foundation for subsequent restoration of physiological occlusal relationships and normalization of mandibular articulatory movements. The treatment protocol included clinical and laboratory stages of temporary and definitive prosthetic rehabilitation. At the first stage, a removable stabilization splint was used to reposition the mandible. The splint was fabricated following transcutaneous electrical nerve stimulation and prescribed for 24 hours per day wear. After 6 months of splint therapy, provisional restorations were fabricated in the newly established maxillomandibular relationship. At the final stage, definitive fixed denture constructions with combined support (teeth and implants) were delivered. Because forced mandibular position syndrome manifests as a constellation of specific symptoms, its diagnosis and management must be individualized. The presented clinical case demonstrates that staged treatment according to the proposed comprehensive protocol improves rehabilitation outcomes in patients with this condition.

BACKGROUND: Orthodontic microimplants placed in the infrazygomatic region are increasingly used in clinical practice. However, no systematic studies have been identified that comprehensively characterize the anatomy of this region and the magnitude of forces acting on a microimplant placed in the infrazygomatic region.

AIM: To evaluate the effects of orthodontic force applied to a microimplant and the surrounding maxillary structures using finite element analysis.

METHODS: A digital model of the maxilla was constructed for a patient undergoing orthodontic treatment with a fixed appliance system and a microimplant placed in the infrazygomatic region. Finite element analysis was performed to assess the influence of orthodontic force on the microimplant and adjacent maxillary structures (including the movable oral mucosa, the cortical plate, and the cancellous bone of the alveolar process).

RESULTS: Under applied loading, the model demonstrated changes in physical parameters. The total deformation of the microimplant was 0.0002 mm, which may be interpreted as minimal and not affecting its stability. Equivalent stress in the model was concentrated in the cortical plate of the maxilla, with the limit reaching 0.021 MPa. Due to the high density of the cortical bone, equivalent stress values in the cancellous bone were several times lower.

CONCLUSION: The deformation processes were localized and remained within physiological limits, confirming appropriate load distribution between the implant and surrounding tissues.

The article presents key milestones in the biography and outlines the principal achievements of Professor Alexander V. Tsymbalistov (1948–2025), Doctor of Medical Sciences, honored physician of the Russian Federation, head of the Department of Prosthodontics at the Medical Institute of Belgorod National Research University BelSU, president of the Belgorod Regional Public Organization Dental Association, and editor-in-chief at the journal The Dental Institute. Professor A.I. Tsymbalistov left a remarkable legacy in Russian dentistry. He never feared competition and consistently promoted active creative collaboration among scientists in dentistry and other medical specialties. He supported young and talented clinicians and generously shared his knowledge and professional experience. For many years, A.I. Tsymbalistov served as Head of the Department of Prosthodontics at the State Institute for Advanced Medical Studies (later St. Petersburg Medical Academy of Postgraduate Education and subsequently North-Western State Medical University named after I.I. Mechnikov) and as Dean of the Faculty of Dentistry. His contribution to the development of a new scientific direction aimed at improving prosthodontic rehabilitation of patients with complicated dental status and underlying systemic diseases—of substantial applied importance for medical science—was invaluable. He was also a talented organizer of annual international and Russian scientific and practical events, including the annual federal championship of professional skills for dental technicians. The achievements of A.I. Tsymbalistov were recognized by numerous awards. The memory of A.I. Tsymbalistov—an extraordinary personality, distinguished leader, highly skilled professional, and a remarkable human being—will forever remain in the hearts of his colleagues, friends, and students.