Tissue changes and tissue reactivity following osteotomy by a conventional rotary device, an ultrasonic unit, and an Er: YAG laser - A comparative study in humans.

INTRODUCTION: Innovative technologies from other fields of science are constantly being introduced in medicine. Research works on animals strongly confirm the belief in better results following ultrasound and laser surgery. The main conclusions are based on observations from different animal species, whose biological characteristics differ from those of humans. This requires scientific experiments to be performed and confirmed in humans. MATERIAL & METHODS: Human mandible specimens harvested in vivo by a conventional low-speed rotary device, an ultrasonic unit, or an Er: YAG laser were studied and analyzed to compare their effects on bone morphology and tissue response following surgery. RESULTS: The cutting surface of eighty biopsies was studied, as well the facial edema, pain levels, and jaw dysfunction were followed up in the same eighty patients from whom the slices were obtained. In the piezosurgery and drill groups, the borders exhibited irregular edges full of bone fragments and debris. Thermal alterations within the superficial surface in all bone samples were generally minimal. In all specimens, intact osteocytes were detectable away from the area of direct action of the bone-cutting device. It was established, that the reactive facial edema, pain levels, and jaw disfunction were with milder values following in vivo osteotomy by an ultrasonic unit and Er: YAG laser compared to the conventional drilling. Moreover, the recovery of the patients in these two groups was more pronounced. The observed tissue changes proved to affect the follow-up tissue reactions in the postoperative period (p ≤ 0.05). DISCUSSION: Based on the established effects on human bone by its in vivo cutting, it can be concluded that laser and ultrasonic bone surgery was a superior alternative osteotomy method in humans to conventional drilling.

Conventional drilling versus ultrasound and laser osteotomy in mandibular third molar surgery: A comparative study.

BACKGROUND: There are few research works with in-depth studies and direct simultaneous comparisons of the effects on tissue reactions and patients' recovery following in vivo conventional drilling, ultrasound- and laser-assisted osteotomy in humans. OBJECTIVE: The current study aims to compare bone cutting duration, pain, swelling, and trismus in patients following surgical mandible third molar extraction by bone removal using three different osteotomes-a conventional rotary device, an ultrasonic unit, and an Er:YAG laser. METHODS: A prospective, randomized three-group comparative clinical trial was performed. As an experimental setting for the study, аn open mandible third molar surgery was chosen because osteotomy is included in its protocol. Patients were divided into three groups according to the used device for bone removal. Bone cutting time intraoperatively, facial swelling, trismus, and pain on the first, second, and third postoperative days were assessed. The statistical analyses were performed using the SPSS v. 17.0-Kolmogorov-Smirnov test, one-way ANOVA, Student's t-test, Mann-Whitney test, and χ2  test. Statistical results were considered significant at p < 0.05 (confidence interval of difference, 95% CI). RESULTS: Eighty patients (34 males and 46 females with an average age of 25.18 years) were included in the study. The average time for bone removal by the conventional low-speed device (4.95 min), by the ultrasonic unit (5.13 min), and by the Er:YAG laser (9.00 min) differed significantly (p = 0.001). The mean postoperative facial swelling showed a marked difference between the groups (p < 0.05), in favor of the laser and piezo groups. The osteotome proved to influence pain intensity not only immediately after surgery (p = 0.002), but also during the followed-up period (p = 0.001), again in favor of the two above-mentioned groups. No association was found between trismus and the osteotome used by the followed-up patients (p > 0.05). CONCLUSION: Bone-cutting mechanism and the biological influence of the laser beam and ultrasound on living tissues proved to be favorable factors for patients' pain levels and tissue swelling postoperatively independent of the longer osteotomy duration compared to conventional drilling.

Intraosseous Epidermoid Cyst: a Case Report.

Background: Epidermoid cysts are benign lesions that occur throughout the body. Their development in the oral cavity is extremely rare. Intraosseous epidermoid cysts of the jaw are even rarer and difficult to distinguish from other lesions. For this reason, we would like to draw the attention of practitioners to this pathology as a differential diagnosis through the presented clinical case. Methods: This study presents an unusual case of a type of epidermoid cyst in an edentulous maxilla. A 70-year-old man was referred to the Maxillofacial Surgery Division at the University Multiprofile Hospital for Active Treatment and Emergency Medicine "N. I. Pirogov", Sofia, Bulgaria, for a single radiolucent area in his anterior maxilla. The patient underwent surgery to extract the cyst. Results: Based on the clinical and radiographic evaluation, a preliminary diagnosis of dentigerous residual cyst was made. The histopathological examination of the hematoxylin and eosin stained sections revealed an epidermoid cyst based on the observed thick keratin layer resembling epidermis together with the stratified squamous epithelium lining with many layers of sheaves of orthokeratin. Conclusions: This report presents an uncommon case of an intraosseous epidermoid cyst occurring without a history of maxillary trauma. Although intraosseous epidermoid cysts are extremely rare in jaws, they should be considered in the differential diagnosis of radiolucent lesions.

Palmaris Longus Muscle Variations: Clinical Significance and Proposal of New Classifications.

BACKGROUND: The palmaris longus muscle is one of the most variable muscles in the human body and there have been numerous variations reported. The different palmaris longus variations are interesting not only from an anatomical point of view, but they could also have definite clinical significance. AIM: The aim of this study was to examine the different types of variations of palmaris longus muscle in the Bulgarian population. MATERIALS AND METHODS: Over a period of 15 years, 56 formol-carbol fixed human cadavers were studied to investigate the different variations of palmaris longus muscle (PLM). RESULTS: Various anatomical variations of PLM have been reported: absence (2.68%); reversed palmaris longus coexisting with an additional abductor digiti minimi muscle (0.89%); digastric (0.89%); palmaris longus with intermediate muscle belly (1.79%) and duplication (1.79%). CONCLUSIONS: To reveal the wide variety of the types of palmaris longus muscle and their importance for clinical practice, we make a brief literature review concerning the different types of variations, their role in the median and ulnar neuropathy in the wrist or as structures simulating a soft tissue tumour and the application of palmaris longus tendon in plastic and reconstructive surgery as grafting material. We also present new systematic anatomical and clinical classifications of palmaris longus variations by dividing them into two simple groups.

Topographical distribution and morphology of NADPH-diaphorase-stained neurons in the human claustrum.

We studied the topographical distribution and morphological characteristics of NADPH-diaphorase-positive neurons and fibers in the human claustrum. These neurons were seen to be heterogeneously distributed throughout the claustrum. Taking into account the size and shape of stained perikarya as well as dendritic and axonal characteristics, Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPHd)-positive neurons were categorized by diameter into three types: large, medium and small. Large neurons ranged from 25 to 35 µm in diameter and typically displayed elliptical or multipolar cell bodies. Medium neurons ranged from 20 to 25 µm in diameter and displayed multipolar, bipolar and irregular cell bodies. Small neurons ranged from 14 to 20 µm in diameter and most often displayed oval or elliptical cell bodies. Based on dendritic characteristics, these neurons were divided into spiny and aspiny subtypes. Our findings reveal two populations of NADPHd-positive neurons in the human claustrum-one comprised of large and medium cells consistent with a projection neuron phenotype, the other represented by small cells resembling the interneuron phenotype as defined by previous Golgi impregnation studies.

Light and electron-microscopic study of leucine enkephalin immunoreactivity in the cat claustrum.

The claustrum is a complex telencephalic structure owing to its reciprocal connectivity with most--if not all--cortical areas. However, there is a paucity of data in the literature concerning its histochemical components, including opioid peptide neurotransmitters. The aim of the present study was to examine the morphology, distribution and ultrastructure of leucine-enkephalin-immunoreactive (Leu-enk-ir) neurons and fibers in the dorsal claustrum (DC) of the cat. Seven healthy, adult male and female cats were used in our study. All animals received humane care. They were irreversibly anesthetized and transcardially perfused with fixative. Brains were removed, postfixed, blocked and sectioned. Sections were incubated with polyclonal anti-Leu-enk antibodies using the Avidin-Biotin-Peroxidase Complex method. Leu-enk-ir neurons and fibers were distributed throughout the DC. Some of the neurons were lightly-stained, while others were darkly-stained. Light-microscopically, they varied in shape: oval, fusiform, multipolar and irregular. With regard to size, they were categorized as small (15 µm or less in diameter), medium (16-20 µm in diameter) and large (21 µm or more in diameter). No specific pattern of regional distribution was found. On the electron microscope level, immunoproduct was observed in neurons, dendrites and terminal boutons. Different types of Leu-enk-ir neurons differ in their ultrastructural features, including two types of synaptic boutons. No gender-specific features were observed. In conclusion, it is our hope that our study will serve to contribute to a better understanding of the functional neuroanatomy of the DC in the cat, and that it can be extrapolated and applied to other mammals, including humans.