Search

BackgroundLoss of the remaining dentition in one or both jaws has a significant bearing on chewing patterns and related forces. Full-arch implanttherapy with fixed prosthetic rehabilitation (All-on-4 technique) aims to accurately restore patients' chewing ability.Aim/HypothesisThe objective of the study was to assess the maximum occlusal bite force among patients equipped with implant-supported fixed orremovable dentures and draw a comparison to dentate and complete denture patients.Materials and MethodsThe bite force of 5 groups of patients (All-on-4 implant bridges, implant overdentures, complete dentures and fully dentate patients)was assessed using a custom-made device measuring forces while chewing in Newton (N) and compared between the groups.Resultats (1000 characters maximum)The mean bite force was 199.2 u00b1 97.0 N for dentate patients, 283.1 u00b1 142.1 N for patients with All-on-4 implant bridges in both jaws,108.1 u00b1 55.7 N in case of All-on-4 rehabilitation in one jaw only (combined with complete dentures or implant overdentures), 90.6 u00b128.6 N with implant overdentures, and only 83.5 u00b1 48.0 N in complete denture patients.Conclusions and Clinical ImplicationsThe results of the present clinical investigation suggest that patients with fixed full-arch implant bridges (All-on-4 technique)demonstrate bite forces similar to or even exceeding fully dentate patients. Patients wearing complete dentures, implant overdenturesor implant bridges in just one jaw, by contrast, show a bite force reduction of -53%.

BackgroundImmediate provisional loading at the day of implant placement according to the All-on-4/5/6-concept offers major benefits for thepatient, such as total avoidance of removable prostheses and no need to adapt to changes regarding function, esthetics as well asphonetics.Aim/HypothesisThe aim of the present study was to investigate technical as well as biological complications (implant failure) associated withprovisional implant bridges in edentulous jaws.Materials and Methods (1000 characters maximum)A total of 765 provisional resin-bonded bridges (glass-fibre reinforced, no cantilevers) supported by 3609 implants were manufacturedfor 652 patients at the day of immediate All-on-4/5/6 implant therapy. The provisional restoration was followed-up until final prostheticdelivery after at least 3 months.ResultatsThe rate of technical complications was 60%, however, three quarters were considered minor and could be solved in office. Majorcomplications (requiring lab technicians) were seen in only 15% and the implant failure rate was 2.2%. Biomechanical complications(bridge fracture, veneer fracture, abutment or screw loosening, screw access channel fillings) were most frequent (66%). 75% ofimplant failures occured within the first 9 months while technical complications were low after 6 months and started accelerating notbefore the first year of loading.Conclusions and Clinical ImplicationsTechnical complications with resin-bonded glass-fibre reinforced full-arch implant bridges are frequent within the first 6 months afterimmediate provisionalization, however, 45% of patients show minor problems that can be solved chairside and only 15% needextensive repair. Extending the provisional phase to up to 1 year does not significantly increase rates of biomechanical complications.

UNLABELLED Various techniques to induce deliberate hypotension (DH) have different influences on splanchnic perfusion. The aim of our study was to determine whether splanchnic perfusion is clinically impaired during DH by using either isoflurane (ISO) or a combination of esmolol and nitroglycerin (E/N). We randomized 16 patients undergoing elective maxillofacial surgery to receive either ISO (0.7%-1.8%) or E (105 g x kg(-1) x min(-1)) and N (1-6 mg/h) to induce DH. General anesthesia was performed in both groups by IV midazolam 0.07 mg/kg, fentanyl 0.003 mg/kg, propofol 1.5 mg/kg, and vecuronium 0.1 mg/kg followed by a propofol infusion with 6 mg x kg(-1) x h(-1). After the induction of anesthesia, a gastric tonometer (TRIP NGS Catheter) and a radial artery catheter were inserted. Baseline values of gastric intramucosal pH (pHi) were determined 60 min after placement of the catheter and before the induction of DH. The pHi values were calculated every 60 min until DH was discontinued. In both groups, DH was satisfactorily established. None of the pHi values calculated was less than 7.37 in the E/N or 7.41 in the ISO group. Arterial blood lactate levels did not increase in any of the patients. We conclude that neither method of producing DH compromises splanchnic tissue oxygen balance in healthy patients. Furthermore, overall organ perfusion was sufficient in both groups, because none of the patients showed an increase in blood lactate. IMPLICATIONS Neither the isoflurane nor the esmolol/nitroglycerin method of producing deliberate hypotension compromises splanchnic tissue oxygen balance in healthy patients. Furthermore, overall organ perfusion was sufficient in both groups, because none of the patients showed an increase in blood lactate.

27 patients, clinically suspected of having parotid tumours, were examined prospectively by sonography (high frequency linear array) and MRI (1.5 T, T1- and T2-weighted SE sequences before, and T1-weighted SE sequences after contrast). In 23 patients, 25 intraglandular tumours were demonstrated (two were multicentric); they consisted of 6 malignant parotid tumours, 11 pleomorphic adenomas, 7 cystadenolymphomas and one oncocytic adenoma. 4 patients had extraglandular tumours. All tumours were demonstrated by either method, but two extraglandular tumours were incorrectly diagnosed by sonography as being intraglandular and 8 tumours (28%) were not completely delineated by sonography. MRI localised the tumours correctly in all cases and demonstrated all lesions accurately, independent of their position or size. In summary, sonography appears suitable as the primary imaging method in the investigation of parotid tumours but in case of large, parapharyngeal or malignant tumours, MRI is clearly superior to sonography.

From October 1990 to March 1994, 90 patients entered a prospectively randomised trial in head and neck cancer. All patients had verified squamous cell carcinoma and were referred for primary radiation therapy. Tumours originated in the oral cavity in 25, oropharynx in 37, larynx in 15 and hypopharynx in 13 cases. Patients' stages were predominantely T3 and T4 (71/90) and had lymph node metastases (60/90). Seventy-nine male patients and 11 female patients, with a median age of 57 years (range 37-76 years) were treated. Patients were randomised to one of three treatment options: conventional fractionation (CF) consisting of 70 Gy in 35 fractions over 7 weeks or continuous hyperfractionated accelerated radiation therapy (Vienna-CHART) or Vienna-CHART with administration of a single dose of mitomycin C on day 5 of treatment (V-CHART + MMC). By the accelerated regimen a total dose of 55.3 Gy was given in 33 fractions within 17 consecutive days. Acute mucositis was the main toxicity recorded in those patients treated by accelerated fractionation, although the overall duration of mucosal reaction did not differ in the three treatment groups. There was no influence on local toxicity if MMC was added to radiation therapy or not. Those patients treated with additional MMC experienced a grade III/IV haematological toxicity in 4/28 cases. Complete remission (CR) was recorded in 48% following CF, 79% after Vienna-CHART (P < 0.05) and 71% after Vienna-CHART + MMC. The overall local failure rates were 73%, 59% and 42% (P = NS) for patients treated by CF, Vienna-CHART and Vienna-CHART + MMC respectively.