Interspecies Comparison of Alveolar Bone Biology, Part I: Morphology and Physiology of Pristine Bone.

INTRODUCTION: Few interspecies comparisons of alveolar bone have been documented, and this knowledge gap raises questions about which animal models most accurately represent human dental conditions or responses to surgical interventions. OBJECTIVES: The objective of this study was to employ state-of-the-art quantitative metrics to directly assess and compare the structural and functional characteristics of alveolar bone among humans, mini pigs, rats, and mice. METHODS: The same anatomic location (i.e., the posterior maxillae) was analyzed in all species via micro-computed tomographic imaging, followed by quantitative analyses, coupled with histology and immunohistochemistry. Bone remodeling was evaluated with alkaline phosphatase activity and tartrate-resistant acid phosphatase staining to identify osteoblast and osteoclast activities. In vivo fluorochrome labeling was used as a means to assess mineral apposition rates. RESULTS: Collectively, these analyses demonstrated that bone volume differed among the species, while bone mineral density was equal. All species showed a similar density of alveolar osteocytes, with a highly conserved pattern of collagen organization. Collagen maturation was equal among mouse, rat, and mini pig. Bone remodeling was a shared feature among the species, with morphologically indistinguishable hemiosteonal appearances, osteocytic perilacunar remodeling, and similar mineral apposition rates in alveolar bone. CONCLUSIONS: Our analyses demonstrated equivalencies among the 4 species in a plurality of the biological features of alveolar bone. Despite contradictory results from older studies, we found no evidence for the superiority of pig models over rodent models in representing human bone biology. KNOWLEDGE TRANSFER STATEMENT: Animal models are extensively used to evaluate bone tissue engineering strategies, yet there are few state-of-the-art studies that rigorously compare and quantify the factors influencing selection of a given animal model. Consequently, there is an urgent need to assess preclinical animal models for their predictive value to dental research. Our article addresses this knowledge gap and, in doing so, provides a foundation for more effective standardization among animal models commonly used in dentistry.

[Treatment Options for Inveterate Injuries of Deep Finger Flexors - Primary Transplantation with Tendon Graft]. / Moznosti osetrení u zastaralých poranení hlubokých flexoru prstu ruky ­ primární transplantace slachovým stepem.

Injuries of the flexor finger apparatus are very common. Primarily, it is routinely treated by suture of the tendon. Isolated deep flexor injuries, when the flexion restriction only reaches the DIP joint, are sometimes overlooked by the surgeon or by the patients themselves, especially if the deep flexor is injured, after a closed rupture or cutaneous injury with a small skin wound. The patient is then sent to a department specializing in hand surgery after a few weeks. Subsequent shortening of the tendon apparatus makes flexor suture more difficult or sometimes even impossible. Many ways of suturing the tendons and subsequent treatment are described. The treatment results vary immensely. It depends on the mechanism of injury, injury zone, the suture suture technique used, time that has elapsed since primary treatment, surgeon experience and subsequent postoperative and rehabilitative care. One of them is reconstruction of the flexor apparatus by primary transplantation of an autologous tendon graft. Most commonly, the tendon graft is taken from the palmaris longusfrom the same hand. The tendon graft can subsitute the entire area of zones I and II. The tendon suture is made in the palm proximal to the A1 pulley outside the tendon sheath in the area where the muscular belly of thelumbricalis is located on the tendon of the deep flexor. The distal end is reinserted to the base of the distal phalanx. The primary use of the autologous tendon graft can be used in the reconstruction of obsolete deep-flexor injuries in Zone II, but also in primary treatments. This type of treatment has a number of advantages. Performing the reinforcement of the tendon at the base of the distal phalanxand the suture in the palm of the hand completely eliminates the complications caused by the tendon suture in zone II. There is no injury to the tendon sheath, or the need for intersection of the tendons. The transplanted tendon is smaller in diameter than the deep flexor, so it can also be used for older injuries when the tendon sheath is in partially missing. It removes painful palmar resistance by restoring the right position and a tension of tendon of lumbricalis and the tendon of the deep flexor. This type of reconstruction allows immediate active or semi-rehabilitation of the hand and fingers. Key words:tendon, injury, hand, transplantation, surgery, flexor, reconstruction, rupture, treatment.

CURRENT TREATMENT OPTIONS OF DUPUYTREN´S DISEASE.

Dupuytren's disease (fibromatosis of the palmar fascia, benign neoplastic fibromatosis, Dupuytren's contracture) is a disease characterized by growth and successive contracture of single parts of the palmar aponeurosis. This condition is known and has been treated for several centuries. In the advanced stages of the disease, it leads to significant limitation of hand function, resulting in reduced quality of life of the patient. Dupuytren's disease (DD) is a life-long disease with a variable course and a heterogeneous clinical presentation. Therapy focuses on the clinical manifestations of the disease as well as on reduction of the functional limitation of the hand caused by the disease. In addition to conservative and surgical procedures, there are also some mini-invasive methods available. Treatment should be reserved for centres and experienced surgeons specialized in hand surgery.

CURRENT CONCEPTS IN PERIPHERAL NERVE INJURY REPAIR.

Even though reconstructive surgery of the nerves underwent significant progress due to experimental and clinical research over the past 40 years, injuries to the peripheral nerves still remain a great challenge for microsurgery. Literature results of these procedures are often evaluated as very good but the final result is often characterized by an achievement of only a useful and not full function, which is rather rare. It is not only a simple suture; the success is also based on functional regeneration and interconnection of the nerve fibres. This is limited by correct surgical technique, the age of the patient, delay from the time of injury and the mechanism or localization of the injury. Some injuries even now remain untreatable (such as the most severe brachial plexus injuries or long traction injuries of the peroneal nerve). Apart from standard neurolysis and epi- or perineural suture with or without nerve grafts, distal nerve transfers (in case of proximal injuries) and end-to-side neurorrhaphy (mainly in trauma of sensitive nerves) have recently been frequently used. The future is however based on influence of nerve regeneration at the cellular level using substances with growth potential. The main prerequisite of successful surgery is however early indication of surgical revision in a specialized centre.

HAS A GLOMUS TUMOR ALWAYS A QUICK DIAGNOSIS?

INTRODUCTION: Glomus tumor is a rare and benign vascular tumor. Although symptoms specific for this tumor are quite clear, there is still a delay between the onset of symptoms, diagnosis and subsequent surgical therapy. The authors monitor the time from the onset of symptoms to the diagnosis and management of the problems. MATERIAL AND METHODS: Between 2004-2012, a total of 5 patients were diagnosed with subungual glomus tumor in the area of the distal phalanges of the hand. It involved 3 women and 2 men with the mean age of 32.2 years (26-47 years). During the first examination, we monitored the duration of symptoms, number and specialty of the doctors who examined the patient, and what examinations were performed. When the cold test was positive, MRI was performed and the patients were indicated for surgical revision. Tissue samples in all patients were histologically examined. Patients were followed for 2 years. RESULTS: It was found that the patients had clinical symptoms for an average of 2.4 years. In our group, the patients were examined by an average of 5.4 physicians (3-9 physicians). On examination before surgery, three patients reported changes in the nail bed and two patients reported no change. When following the patients 2 years after the surgery, relapse occurred in one patient and it was treated with reoperation. During regular follow-up 2 years after the surgery, 4 patients were without nail deformity. In one patient, there was resulting nail deformity. Relapse occurred in only one case. DISCUSSION: Because the glomus tumor is a rare lesion, occurring most frequently in the nail bed, early diagnosis is still a problem. Even in literature, we encounter a similar time frame from the onset of symptoms until the final diagnosis of 1.9 to 8 years. CONCLUSION: Although clinical signs and problems concerning the glomus tumor are very obvious, there still remains a long time for diagnosis. It would certainly be most beneficial for patients with persistent symptoms not to be referred to different specialists, but directly to a department that specializes in hand surgery.