Diagnosis and treatment of Eagle's syndrome and possible complications.

BACKGROUND: Eagle's syndrome (ES) is a term describing a group of symptoms associated with the elongation of the styloid process (SP) of the temporal bone or with ossification of the stylohyoid ligament. Clinically, it manifests through pain in the orofacial and pharyngeal regions, similar to that experienced by patients with temporomandibular joint disease. The presented paper aims to assess the evaluation of the success of surgical treatment and the complications associated with such treatment. METHODS: Our retrospective study includes nine patients with ES treated in our Department Oral and Maxillofacial Surgery in years 2019-2023 (median age of 47 years) - all patients affected with this disease out of 2,716 patients examined at our department due to a temporomandibular joint disease. Eight of these patients underwent a surgical resection of the SP. The success and complications in these patients are evaluated in this study. RESULTS: In seven patients, the problems disappeared or at least diminished, which is consistent with data from the literature. Postoperative complications such as deficit of the marginal branch of the facial nerve (n. VII), limited sticking the tongue out (n. XII), and velopharyngeal insufficiency (n. IX) occurred in three patients. CONCLUSION: The wide spectrum of clinical manifestations makes ES a condition that should be considered in the differential diagnosis of temporomandibular joint disorders, post-traumatic conditions, or complicated eruption of wisdom teeth or their extraction. ES can be treated conservatively or (mostly) surgically. Surgical treatment can be relatively successful and effective, but it is necessary to respect the anatomical placement of the SP, which can be associated with the development of complications, especially in cases with extremely long SP.

GUNSHOT INJURIES OF THE OROFACIAL REGION.

Between 2000 and 2010, approximately 10,000 gun attacks resulting in death were registered in the EU countries. In the same period and region, approximately 40,000 suicides took place, 1,500 of which were in the Czech Republic. 82% of suicides or suicide attempts using a firearm (or another projectile weapon) led to a head injury. Typically, the shots target the temporal or submental region. The severity of the suffered injuries depends besides the wound site, projectile calibre and energy also on other factors such as the projectile trajectory, formation of secondary projectiles, shot reflection from the skeletal structures, etc. Gunshot wounds aimed at the splanchnocranium usually lead to injuries of the mandible(s), maxilla(e), orbit(s) and nose, i.e. of regions associated with multiple fields of medicine requiring multidisciplinary cooperation. The presented paper aims to explain in detail the destructive effects of gunshot injuries in the orofacial regions and to describe the recommended procedure during primary medical treatment. The team of authors aimed to clearly present important information originating both from literature and practical experience with this type of injury.

Radiography, computed tomography and magnetic resonance imaging of craniofacial structures in pig.

The pig has recently become popular as a large animal experimental model in many fields of biomedical research. The aim of this study is to evaluate the basic anatomical structures in the head region of the pig to lay the groundwork for its practical clinical usage or pre-clinical research in the future. We used three different diagnostic imaging methods: radiography, computed tomography (CT) and magnetic resonance imaging (MRI). The analysis showed that radiographic imaging is suitable only for general evaluation of the facial area of the pig skull. CT images showed excellent spatial definition of bony structures of the whole craniofacial area, and MRI images revealed fine soft tissue details. Radiography is preferentially suited to general assessment of bone structures of the facial skeleton; however, the thick layer of adipose tissue in the craniofacial region of the pig makes the imaging of some parts difficult or even impossible. CT is useful for revealing morphological details of mineralized tissues, whereas MRI is more suitable for soft tissue analysis and the detection of subtle pathologic changes in both bone and soft tissues. Therefore, before using pigs as an experimental model in craniofacial research, it is necessary to evaluate the suitability and disadvantages of potential imaging methods and how appropriate they are for accurate visualization of desired structures.

Investigation of an autologous blood treatment strategy for temporomandibular joint hypermobility in a pig model.

Many different surgical and non-surgical techniques are used for the treatment of temporomandibular joint (TMJ) hypermobility. One of these methods is autologous blood injection into the TMJ. The fate of the autologous blood used for treatment of recurring condylar dislocation is still not completely understood. The authors used 12 pigs (Sus scrota f. domestica) as a model species for autologous blood delivery into the TMJ. Blood injection was followed by histopathological analysis at different times after treatment (1h, 1, 2 and 4 weeks). Samples were examined by magnetic resonance imaging, macroscopic and histological methods. The deposition of the remaining blood was observed in the form of clots in the distal parts of the upper joint cavity 1h and 1 week after treatment. 2 weeks after treatment, small blood clots were still apparent in the distal part of the upper joint cavity. 4 weeks after surgery, no remnants of blood, changes or adhesions were apparent inside the TMJ. No morphological or histological changes were observed in the TMJ after the injection of autologous blood suggesting another mechanism is involved in the hypermobility treatment.

The pig as an experimental model for clinical craniofacial research.

The pig represents a useful, large experimental model for biomedical research. Recently, it has been used in different areas of biomedical research. The aim of this study was to review the basic anatomical structures of the head region in the pig in relation to their use in current research. Attention was focused on the areas that are frequently affected by pathological processes in humans: the oral cavity with teeth, salivary gland, orbit, nasal cavity and paranasal sinuses, maxilla, mandible and temporomandibular joint. Not all of the structures have an equal morphology in the pig and human, and these morphological dissimilarities must be taken into account before choosing the pig as an experimental model for regenerative medicine.

Early regression of the dental lamina underlies the development of diphyodont dentitions.

Functional tooth germs in mammals, reptiles, and chondrichthyans are initiated from a dental lamina. The longevity of the lamina plays a role in governing the number of tooth generations. Monophyodont species have no replacement dental lamina, while polyphyodont species have a permanent continuous lamina. In diphyodont species, the dental lamina fragments and regresses after initiation of the second tooth generation. Regression of the lamina seems to be an important mechanism in preventing the further development of replacement teeth. Defects in the complete removal of the lamina lead to cyst formation and has been linked to ameloblastomas. Here, we show the previously unknown mechanisms behind the disappearance of the dental lamina, involving a combination of cell migration, cell-fate transformation, and apoptosis. Lamina regression starts with the loss of the basement membrane, allowing the epithelial cells to break away from the lamina and migrate into the surrounding mesenchyme. Cells deactivate epithelial markers (E-cadherin, cytokeratin), up-regulate Slug and MMP2, and activate mesenchymal markers (vimentin), while residual lamina cells are removed by apoptosis. The uncovering of the processes behind lamina degradation allows us to clarify the evolution of diphyodonty, and provides a mechanism for future manipulation of the number of tooth generations.