Clinical Anatomy of the Ligaments of the Face and Their Fundamental Distinguishing Features.

Our study aimed to clarify the anatomical features of the zygomatic, upper masseteric, lower masseteric and mandibular ligaments and their possible contribution to age-related gravitational ptosis. The study was carried out by the method of layered dissection of fresh cadavers. In several observations, the zygomatic ligament is represented by the fibers originating from the zygomaticus major muscle fibers. It is a true ligament with the fibers inserted directly into the skin. The upper and lower masseteric ligaments originate from the parotideomasseteric fascia and weave into the thickness of the SMAS. The mandibular ligament consists of two connective tissue laminae originating from the parotideomasseteric fascia at the lower edge of the mandible and from the inner surface of this fascia, along the anterior edge of the masseter muscle, skirting the facial vein sheath and the facial artery, traveling toward the platysma and the depressor anguli oris muscle, and merging with their fibers. The zygomatic ligament should be considered an osteo-musculocutaneous ligament, emphasizing the role of the associated zygomaticus major muscle in the mechanism of aging. The upper and lower masseteric and mandibular ligaments are false fascio-SMAS ligaments rather than osteo-cutaneous ones, playing the barrier role and fixing the superficial fascia and the platysma muscle.

Polytrauma Caused by a Bear Attacking a Human with a Benign Outcome.

Injuries to humans caused by wild animals, particularly bears, are rarely mentioned in the literature. Such injuries are frequent in Siberia, which is a territory surrounded by dense forests inhabited by brown bears. In the last 4 months alone (September-December 2023), four bear attacks on humans were registered in Khakassia, Russia. This article presents a clinical case of rehabilitating a patient after a bear attack, who suffered multiple fragmentary fractures of the facial skeleton with displaced bone fragments, subcutaneous emphysema of the soft tissues of the face, damage to the parietal and right occipital regions and paranasal sinus hemorrhage on the left side. The nature of the injuries was enhanced by trauma to the upper extremity caused by the patient defending himself against the animal. In addition to the damage to his face, the bear tried to open his cranium, as evidenced by four furrows caused by its canines, including two each on the frontal and occipital bones of the skull. The patient's complex treatment included both maxillofacial and reconstructive surgeries, and outpatient treatment involved the formation of normotrophic scars using a neodymium laser and injections of a heterogeneous composition consisting of microparticles of "crosslinked" collagen of animal origin placed in a gel identical to the natural extracellular matrix.

A New Way to Model Periodontitis in Laboratory Animals.

The prevalence of periodontal diseases is increasing, tends to increase with age and is considered as one of the main causes of tooth loss. To assess the effectiveness of new methods of treatment of periodontal diseases, studies on laboratory animals can be promising. THE AIM OF THE STUDY: to develop a new method of accelerated modeling of experimental periodontitis on laboratory animals. MATERIAL AND METHODS: The study was carried out on 22 female rats. A wire ligature was applied to the cervical area of the incisors of the animals in an eight-shaped manner. Plaque obtained from a patient with periodontitis was placed under the wire, and nicotine and ethyl alcohol solutions were injected under the gingival mucosa. A complex index has been proposed to assess inflammation. At the end of the experiment the animals were euthanized, their jaws were dissected into dentoalveolar blocks and further descriptive histologic analysis was performed. RESULTS: On the second day the gingiva of the rats acquired a cyanotic-pink color, on the fourth day the consistency of the gingiva became friable, mobility appeared in the lower incisors. Complex index of inflammation in animals of the main group: before the study-9, on the 7th day-195. Gingival preparations showed signs of exudative inflammation. In alveolar processes-irreversible resorption of bone structures. The difference of indicators in animals before and after the experiment was statistically significant (p < 0.05). CONCLUSION: The new experimental model of periodontitis is reproduced in a short period of time, provides intensive development of inflammation, leads to disruption of the integrity of epithelial and connective tissue attachment, destruction of alveolar bone.

Comparative Analysis of Mechanical Properties and Microbiological Resistance of Polyfilament and Monofilament Suture Materials Used in the Operation "Tooth Extraction".

In surgical dentistry, suture material is the only foreign body that remains in the tissues after surgery, and it can lead to several negative reactions, for example, infection of the wound. The purpose of this study was to compare the mechanical properties and microbiological resistance of mono- and polyfilament suture materials used in tooth extraction operations. The study of elongation and knot force was carried out on an Instron 5969 Dual Column Testing System device. The capillarity of the materials was studied on a setup assembled by the authors manually by immersing the ends of the filaments in a colored manganese solution. A microbiological study was carried out on the threads taken for the experiment immediately after wound suturing, and on day 7, at which time they were removed. The comparison was made according to Rothia mucilaginosa, Streptococcus sanguinis, Staphylococcus epidermidis. Results: monofilament suture materials (Prolene and Glycolon), after calculating the Kruskal-Wallis and Mann-Whitney indices, showed better performance in all experiments compared to polyfilament sutures (Vicryl and PGA). In capillarity comparison, there was a significant difference between groups (p = 0.00018). According to the sum of the results of three microbiological studies on day 7, monofilament suture materials absorbed less of the studied bacteria on their surface compared to the polyfilament ones (p < 0.05). Conclusions: Of the studied suture materials, Prolene had the best microbiological resistance and good mechanical properties.

X-ray and anatomical features of the lower jaw alveolar cortical layer in children.

INTRODUCTION: the world studies showed the interest in measurement of the buccal or anterior cortical plate thickness. Data indicate a significant superiority of the spongy substance over the compact one in the distal part of the jaw, which makes it possible to think about a higher effectiveness of transcortical injections. The empirical "rule of 10″ provides for the choice of a method of anesthesia in children for primary teeth but demonstrates difficulties with high-quality anesthesia accompanied for permanent teeth. Therefore, the importance of clinical examination and anatomical investigation of the jaw cortical plate in children for competent planning of transcortical interventions has been determined. AIM: To study the features of the clinical and X-ray anatomy of the cortical layer in distal alveolar part of the mandible in children. MATERIAL AND METHODS: The assessment of the X-ray anatomical characteristics of the mandible was carried out according to 150 anonymized cone-beam computed tomograms of patients aged 6-12 years, performed for the treatment of major diseases. Qualitative assessment and examination of the cortical plate of the distal alveolar part of the mandible were carried out on the skeletonized certified preparations of aged 6-12 in the amount of 50. RESULTS: The age characteristics of the cortical plate in the area of the chewing group of teeth in the mandible were determined according to macro anatomical studies, which confirms with the X-ray results. Therefore, the obtained images serve as actual confirmation of X-ray studies, which are ranked by age. The thickness of the cortical plate in the second primary molar of the mandible in subgroups 6, 7 and 8 years has a proportional increase from the cervical region to the apical projection. The average thickness of the cortical plate is 1.57 mm at 6 years, 1.52 mm at 7 years, 1.6 mm at 8 years and 1.84 at 9 years. The cortical plate thickness in the first primary molar of the mandible in subgroups 6 and 7 years has a proportional decrease from the cervical region to the apical projection as well as an inverse proportion to age. The average thickness of the cortical plate is 1.33 mm. In the first molar of the mandible at the age limit of 6-12 years the attention is drawn to the linear increase in tissue volume from the cervical region to the apical projection up to 8 years. At 6-8 years the average thickness of the cortical plate in this age group is 1.74 ± 0.2 mm, at 9 years - 2.03 mm, at 10 - average value in the cervical region it is 1.53 ± 0.23 mm, in the root middle it is 2.19 ± 0.13 mm and in the apical projection it is 1.98 ± 0.16 mm, at 11-2.22 mm and at 12-2.35 mm. For the second primary molar the average thickness of the buccal cortical plate of the second primary molar is 1.4 mm in cervical part, 1.68 mm in the root middle and 1.81 mm in the apical projection. Finally, thickness of the buccal cortical plate in the cervical region of the first permanent molar is 2 mm in groups. CONCLUSION: The study makes it possible to determinate with noninvasive way the age limit for the least pronounced zone of the buccal cortical plate.

Evaluation of the Changes of Salivary pH among Dental Students Depending on Their Anxiety Level.

OBJECTIVES: The aim of this study was to determine the correlation between the state of anxiety (S-anxiety and T-anxiety based on the state-trait anxiety inventory [STAI] test) and the manifestation of dentophobia with changes in salivary pH. MATERIALS AND METHODS: The data of 105 patients, aged 18 to 23 were considered. The student's anxiety levels were evaluated by the STAI test and they were distributed into three groups. To determine dental anxiety, Corah's dental anxiety scale (CDAS) testing was performed. To determine the changes in salivary pH, samples were obtained, and pH level of the collected whole saliva was evaluated immediately using pHSCAN 5.4-10.0 litmus paper and a scale in 0.1 to 0.4 increments. Statistical significance was set at 0.05. RESULTS: Group I experienced a low level of anxiety and included 33 students (31.4%). Group II comprised of 32 (30.5%) students presenting with a moderate level of anxiety. In group III, 40 students (38.1%) were having a high level of anxiety. Out of the 105 participants, 85% of students showed low level of dentophobia, 27% of them showed a low level of anxiety, 29% showed moderate level of anxiety, and 28% showed high level of anxiety. The average salivary pH value among all the participants (105 students) at rest was 6.79 and in a state of anxiety 6.43. CONCLUSION: within the limits of this study, a correlation was found between the anxiety level and the salivary pH level. Furthermore, a change in the salivary pH toward acidity was registered in each group of students when in a stressful situation.