Piezosurgery prevents brain tissue damage: an experimental study on a new rat model.

Piezosurgery is a promising meticulous system for bone cutting, based on ultrasound microvibrations. It is thought that the impact of piezosurgery on the integrity of soft tissue is generally low, but it has not been examined critically. The authors undertook an experimental study to evaluate the brain tissue response to skull bone removal using piezosurgery compared with a conventional drilling method. In Wistar male rats, a circular bone window was drilled to the parietal bone using piezosurgery on one side and a conventional bone drill on the other side. The behavioural performance of animals was evaluated using the motor BBB test and sensory plantar test. The brains of animals were evaluated by magnetic resonance imaging (MRI) and histology. The results of MRI showed significantly increased depth and width of the brain lesion in the region of conventional drilling compared with the region where piezosurgery was used. Cresylviolet and NF 160 staining confirmed these findings. There was no significant difference in any of the behavioural tests between the two groups. In conclusion, piezosurgery is a safe method for the performance of osteotomy in close relation to soft tissue, including an extremely injury-sensitive tissue such as brain.

The role of intraoperative positioning of the inferior alveolar nerve on postoperative paresthesia after bilateral sagittal split osteotomy of the mandible: prospective clinical study.

Bilateral sagittal split osteotomy (BSSO) aims to correct congenital or acquired mandibular abnormities. Temporary or permanent neurosensory disturbance is the most frequent complication of BSSO. To evaluate the influence of IAN handling during osteotomy, the authors undertook a prospective study in 290 patients who underwent BSSO. The occurrence and duration of paresthesia was evaluated 4 weeks, 3 months, 6 months, and 1 year after surgery. Paresthesia developed immediately after surgery in almost half of the patients. Most cases of paresthesia resolved within 1 year after surgery. A significantly higher prevalence of paresthesia was observed on the left side. The authors found a correlation between the type of IAN position between the left and right side. The type of split (and IAN exposure) did not have a significant effect on the occurrence or duration of neurosensory disturbance of the IAN. The authors did not find a correlation between the occurrence and duration of paresthesia and the direction of BSSO. Mandibular hypoplasia or mandibular progenia did not represent a predisposition for the development of paresthesia. In the development of IAN paresthesia, the type of IAN exposure and the split is less important than the side on which the split is carried out.

Hemimandibulectomy and therapeutic neck dissection with radiotherapy in the treatment of oral squamous cell carcinoma involving mandible: a critical review of treatment protocol in the years 1994-2004.

This retrospective non-randomized 10-year follow-up study compared 147 patients with squamous cell carcinoma (SCC) of the oral cavity requiring hemimandibulectomy, treated by surgical resection, therapeutic neck dissection and radiotherapy. The 5-year survival rates were compared related to localization, size of the tumour, infiltration of locoregional lymph nodes, distant metastases, histopathological grading, radicality of surgery, and invasion of tumour into the mandible. Occurrence of tumour relapse and its localization was studied. The mean 5-year survival rate was 26%. Patients with SCC of the mandibular alveolar process had higher rates; the lowest rates occurred in SCC of the buccal mucosa. Survival rate was significantly lower with insufficient resection of the tumour (85% relapse). An important number of patients with radical resection died within 3 months of surgery. In almost 55% of the mandibles tumour was not present. In 5% of infiltrated mandibles, dissemination into inferior alveolar nerve was proven. Decreasing survival rate was seen with increasing size of tumour and higher histological grade. Therapeutic neck dissection significantly reduces survival rate and increases the percentage of lymph node relapse. Elective neck dissection should be performed in SCC requiring hemimandibulectomy. Primary reconstruction should reverse the high percentage of postoperative complication arising from increased radicality.

[Experience with the Thymatron DG apparatus in determining the duration of electroconvulsions]. / Zkusenosti s prístojem Thymatron DG pri stanovení délky elektrokonvulze.

Electroconvulsive therapy was administered, using a Thymatron apparatus DG in a group of 29 female patients with a total number of 150 convulsions. The apparatus makes it possible to take an EEG reading and to evaluate it automatically. Moreover, the paroxysm were evaluated clinically and visually from EEG tracings. The authors proved a significant disagreement as regards evaluation of the length of electroconvulsions assessed by the three methods of evaluation (clinical, automatic EEG analyzer and visual EEG evaluation). They identified moreover in the group, using the automatic EEG analyzer, 11.7% abortive convulsions, by visual EEG evaluation 10.3%, while according to clinical evaluation the rate was as high as 59.2%. Conversely on clinical evaluation no convulsion appeared to be protracted, while according to EEG this was the case in 9.6% (automatic analyzer) and in 10.3% (visual evaluation). On qualitative discrimination of abortive and protracted convulsions and convulsions with a satisfactory duration the automatic and visual EEG evaluation did not differ significantly, and the function of the automatic analyzer seems satisfactory for this basic evaluation of electroconvulsions.

[Sleep apnea syndrome--serious complications in a female patient treated with psychopharmaceutic agents]. / Syndrom spánkové apnoe--závazné komplikace u pacientky lécené psychofarmaky.

The authors present the case-history of a patient treated in the past on account of depressive syndrome who suffered repeatedly from somnolence or even unconsciousness with dyspnoea which called for hospitalization in an anaesthesiological and resuscitation department. The repeatedly expressed suspicion of attempted suicide by drugs was always ruled out by toxicological examination. Based on the clinical picture a preliminary diagnosis of the sleep apnoea syndrome was established confirmed later by polysomnographic examination. The evoking factors of the mentioned serious complications were probably respiratory infections and psychiatric medication, in particular hypnotics--flunitrazepam and triazolam.