Dieter Weingart

Cytokeratin 8/18 expression indicates a poor prognosis in squamous cell carcinomas of the oral cavity

BackgroundIntermediary filaments are involved in cell motility and cancer progression. In a variety of organs, the expression of distinct intermediary filaments are associated with patient prognosis. In this study, we seeked to define the prognostic potential of cytokeratin and vimentin expression patterns in squamous cell carcinomas (SCCs) of the oral cavity.Methods308 patients with histologically proven and surgically treated squamous cell carcinomas of the oral cavity were investigated for the immunohistochemical expression of a variety of intermediary filaments including high- and low-molecular weight cytokeratins (Cks), such as Ck 5/6, Ck 8/18, Ck 1, CK 10, Ck 14, Ck 19 and vimentin, using the tissue microarray technique. Correlations between clinical features and the expression of Cytokeratins and vimentin were evaluated statistically by Kaplan-Meier curves and multivariate Cox regression analysis.ResultsThe expression of Ck 8/18 and Ck 19 were overall significantly correlated with a poor clinical prognosis (Ck 8/18 p = 0.04; Ck19 p < 0.01). These findings could also be reproduced for Ck 8/18 in primary nodal-negative SCCs and held true in multivariate-analysis. No significant correlation with patient prognosis could be found for the expression of the other cytokeratins and for vimentin.ConclusionThe expression of Ck 8/18 in SCCs of the oral cavity is an independent prognostic marker and indicates a decreased overall and progression free survival. These results provide an extended knowledge about the role of intermediary filament expression patterns in SCCs.

Masseter muscle thickness, chewing efficiency and bite force in edentulous patients with fixed and removable implant‐supported prostheses: a cross‐sectional multicenter study

OBJECTIVES Edentulous patients may be restored with conventional dentures (C/C), implant-supported overdentures (IOD) or implant-supported fixed dental prostheses (IFDP). Null-hypotheses: chewing efficiency, maximum voluntary bite force (MBF) and masseter muscle thickness (MMT) are lower in patients with C/IOD compared with the patients with bimaxillary IFDPs. Both groups perform better than C/C and are inferior to fully dentate controls. MATERIAL AND METHODS Ethical approval was obtained. For this multicenter cross-sectional study, 80 patients were recruited. Four groups of different dental states comprised of either implant-supported prostheses (C/IOD and IFDP/IFDP) or served as control-groups (C/C and fully dentate D/D). Chewing efficiency was assessed with a two-colour mixing ability test. MBF was measured bilaterally with a force gauge. Two dimensional ultrasonography was used to measure MMT bilaterally. RESULTS Chewing efficiency in C/IOD and IFDP/IFDP (difference NS) was better than in C/C, but not as good as in D/D. MBF in C/IOD was lower than in IFDP/IFDP. Chewing efficiency and MBF were significantly lower in IFDP/IFDP, who had experienced chipping or fracture of the prosthetic superstructure. Median MMT of patients with implant-supported prostheses was between those with C/C and fully dentate participants. There was no significant difference in MMT between C/IOD and IFDP/IFDP. CONCLUSION Supporting complete prostheses with oral implants seems to have positive effects on the thickness of the masseter muscle, maximum bite force as well as chewing efficiency. The type of implant-supported prostheses may have an influence on the magnitude of the effect.

Submerged and transmucosal healing yield the same clinical outcomes with two‐piece implants in the anterior maxilla and mandible: interim 1‐year results of a randomized, controlled clinical trial

OBJECTIVES To test whether or not transmucosal healing at two-piece implants is as successful as submerged placement regarding crestal bone levels and patient satisfaction. MATERIAL AND METHODS Adults requiring implants in the anterior maxilla or mandible in regions 21-25, 11-15, 31-35 or 41-45 (WHO) were recruited for this randomized, controlled multi-center clinical trial of a 5-year duration. Randomization was performed at implantation allowing for either submerged or transmucosal healing. Final reconstructions were seated 6 months after implantation. Radiographic interproximal crestal bone levels and peri-implant soft tissue parameters were measured at implant placement (IP) (baseline), 6 and 12 months. Patient satisfaction was assessed by a questionnaire. A two-sided t-test (80% power, significance level α=0.05) was performed on bone-level changes at 6 and 12 months. RESULTS One hundred and twenty-seven subjects were included in the 12-month analysis (submerged [S]: 52.5%, transmucosal [TM]: 47.2%). From IP to 6 months, the change in the crestal bone level was -0.32 mm (P<0.001) for the S group and -0.29 mm (P<0.001) for the TM group. From IP to 12 months, bone-level changes were statistically significant in both groups (S -0.47 mm, P<0.001; TM -0.48 mm, P<0.001). The mean differences of change in the bone levels between the two groups were not statistically significant at either time point, indicating the equivalence of both procedures. For both groups, very good results were obtained for soft tissue parameters and for patient satisfaction. CONCLUSIONS Transmucosal healing of two-piece implants is as successful as the submerged healing mode with respect to tissue integration and patient satisfaction within the first 12 months after IP.

Use of a mandibular fracture score to predict the development of complications

PURPOSE Mandibular fractures are common facial injuries. Classifications are diverse and sometimes correlated with specific treatment modalities. Osteosynthesis using plate and screws is the standard method of fracture treatment. To evaluate the outcome of such fracture management in our clinic, we developed a numeric scoring system for mandibular fractures and investigated the relationship between the scoring of the fracture being treated and the incidence of complications after surgical treatment. PATIENTS AND METHODS Seventy-six adult patients treated over a 2-year period were evaluated, and the fractures were classified using the mandibular trauma score. This score was based on clinical and radiologic evaluation of each fracture line and ranks from 0 to 15 points. Osteosynthesis was performed using the AO plate systems. Patients were followed-up postoperatively for the presence of complications. RESULTS During the 2-year period, 76 patients with 134 fractures underwent plate osteosynthesis. Fracture scoring indicated a homogeneous distribution between uncomplicated and severe fractures. The incidence of complications increased with the fracture severity, assessed by the fracture score index. Severe fractures showed fewer complications when treated with a rigid plate system, whereas low-score fractures showed better results when treated with less rigid systems. CONCLUSIONS The numeric scoring system for mandibular fractures allows an objective and standardized assessment of the degree of severity of a fracture and may facilitate decisions about the use of specific treatment modalities.

Hämostyptische Wundversorgung bei Marcumarpatienten

Unter einer Marcumardauerantikoagulation wurden 124 Patienten zur Effektivität hämostyptischer Wundversorgungsarten nach oralchirurgischen Eingriffen untersucht. Der therapeutische Bereich der erforderlichen Antikoagulation wurde nach den Empfehlungen der American Heart Association festgelegt („low risk“: 2,0 < INR < 3,0; „high risk“ 2,5 < INR ¶< 3,5) und während der Behandlung eingehalten. Bei einer Gruppe wurden die Alveolen mit Kollagenvlies versorgt, bei einer 2. Gruppe kam ein Mundspülregime mit Tranexamsäurelösung zur Anwendung. 23 Patienten wurden wegen Abweichung ihrer Gerinnungsparameter vom therapeutischen Bereich ausgeschlossen. In der mit Kollagen versorgten Gruppe verblieben 31, in der Gruppe „Tranexamsäurelösung“ 32 Patienten. Ein 3. Patientenkollektiv (n = 38), in welchem unter kontrollierter Reduktion der Marcumarmedikation alle Alveolen zur Hämostase plastisch gedeckt worden waren, wurde mit den oben genannten Gruppen verglichen. Das chirurgische Vorgehen wurde detailliert vorgeschrieben. Die Nachblutungshäufigkeit war bei Kollagenvlies 19%, bei Tranexamsäurebehandlung 6%, bei plastischer Deckung 40%. Die Fallzahl und die Vielzahl der Parameter ließen keine statistischen Tests zu. Das Datengut wurde deskriptiv betrachtet: anhand von Tabellen der Binominalverteilung wurden Konfidenzintervalle festgelegt. Zwischen der Gruppe „Tranexamsäurelösung“ und der Gruppe „plastische Deckung“ ließ sich der Unterschied in der Häufigkeit der Nachblutungen bestätigen. A total of 124 patients on oral anticoagulation therapy with coumarin were treated by orosurgical procedures and entered into a study to determine the hemostatic efficiency of different methods. The therapeutic anticoagulation level was determined in accordance with the recommendations of the American Heart Association (low risk: 2.0 < INR < 3.0; high risk: 2.5 < INR < 3.5) and maintained during treatment. In one group, the alveoli were treated with collagen, in a second group a mouthrinse regime with tranexamic acid was implemented. Twenty-three patients had to be excluded because anticoagulation levels differed from the recommended values. The group treated with collagen included 31 patients, the group with tranexamic acid mouthwashes, 32 patients. A third group was analyzed in which a controlled change in the anticoagulation level had been performed and all treated alveoli had been covered by mucosal flaps (n = 38); they were compared to the other two groups. The surgical proceedings were outlined precisely. Patients treated with collagen had a bleeding rate of 19%, patients with tranexamic acid mouthwash 6%, and those treated with mucosal flaps 40%. The data were not suited for statistical evaluation, they were objected to a descriptive analysis: the confidence intervals were determined by tables for binomial distributions. These did confirm the difference in the frequency of bleeding for the tranexamic acid and mucosal flap groups.

Clinical and Radiologic Outcomes after Submerged and Transmucosal Implant Placement with Two‐Piece Implants in the Anterior Maxilla and Mandible: 3‐Year Results of a Randomized Controlled Clinical Trial

PURPOSE The aim of this investigation was to evaluate the 3-year outcomes regarding crestal bone level, clinical parameters, and patient satisfaction, following submerged and transmucosal implant placement for two-piece implants in the anterior maxilla and mandible. MATERIALS AND METHODS Patients requiring dental implants for single-tooth replacement in the anterior maxilla or mandible were enrolled in a randomized, controlled, multicenter clinical trial. The implants were randomized at placement to either submerged or transmucosal healing, with final restorations placed after 6 months. Radiographic and clinical parameters were recorded after 1, 2, and 3 years; a questionnaire was also used to assess patient satisfaction. A two-sided, unpaired T-test (significance level p ≤ .05) was used to statistically evaluate the differences between the two groups. RESULTS A total of 106 patients were included in the 3-year analysis. The mean change in crestal bone level from implant placement to 3 years was 0.68 ± 0.98 mm (p < .001) and 0.58 ± 0.77 mm (p < .001) in the submerged and transmucosal groups, respectively; the differences between the groups were not significant. Clinical parameters remained stable throughout the study, with no significant differences between the groups, and patient satisfaction was good or excellent for over 90% of subjects in both groups. CONCLUSIONS The results demonstrate excellent clinical and radiographic conditions after 3 years for implants supporting single-tooth restorations, regardless of whether a submerged or transmucosal surgical technique was used.

Resorbierbares Osteosynthesematerial bei Kraniosynostosen

Hintergrund: Die Ergebnisse der über 4-jährigen Anwendung resorbierbarer Osteosyntheseplatten und -schrauben (82% Polymilchsäure und 18% Polyglykol) zur Kraniosynostosenkorrektur werden dargestellt. Dabei war insbesondere die Frage von Interesse, ob mit dieser Technik im Hinblick auf die Stabilität und die Gewebeverträglichkeit eine Alternative zur Verwendung von Titan besteht. Ergebnisse: Die mit dieser Methode behandelten 30 Kinder mit Kraniosynostosen wurden regelmäßig hinsichtlich der Stabilität und der Symmetrie der Schädelform, der Palpabilität und der Sichtbarkeit der Platten und auf Gewebeunverträglichkeitsreaktionen klinisch untersucht und fotodokumentiert. Die technische Durchführung der Osteosynthesen mit den resorbierbaren Platten und Schrauben erwies sich als zuverlässig. In 1 Fall war die Knochenstärke für den Schraubenhalt nicht ausreichend. Während der Nachbeobachtungszeit von maximal 4 Jahren und 1 Monat zeigten sich die Fixationen als stabil und ohne Nebenwirkungen. Diskussion: Der Einsatz von resorbierbaren Materialien ist, bei weiterer Bestätigung im Langzeitergebnis, ein Erfolg versprechendes Konzept zur Stabilisierung der Segmente in der kraniofazialen Chirurgie bei Kindern. Background: The results of using resorbable plates and screws (82% polylactic acid and 18% polyglycolic acid) in craniofacial surgery for the correction of craniosynostosis after more than 4 years of experience are presented. Special attention is focussed on the degree of stability and the clinical tissue response to the material employed to answer the question of whether the material is an adequate alternative to titanium. Methods: Thirty patients who had been treated with this method for craniosynostoses were examined at regular intervals regarding the shape and stability of the forehead region, visibility and palpability of the plates, and tissue reactions. Results: The technical handling of the osteosynthesis material proved to be simple and reliable. In one case the bone was not strong enough for the screw pitch. After an observation period of a maximum of 4 years and 1 month, the fixations were stable with no signs of adverse reactions. Discussion: If the long-term results remain favorable, we consider the use of resorbable material a promising method for the stabilization of segments in craniofacial surgery in children

Orale Manifestationen bei Patienten mit systemischem Lupus erythematodes

Bei 46 Patienten mit gesichertem systemischen Lupus erythematodes (SLE) wurden die Häufigkeit und Schwere oraler Läsionen und Parodontalerkrankungen bestimmt. Innerhalb des untersuchten Kollektivs wurde nach klinischen Kriterien der Ausprägung des SLE zwischen leicht (n=20) bzw. schwer (n=26) erkrankt differenziert. Die Manifestationsrate oraler Läsionen in dem untersuchten Patientengut lag bei 48%, mit einer höheren Rate bei schwerer (54%) gegenüber leichter (40%) Erkrankung. Bei vergleichbarer Zahnpflege (bestimmt anhand des Approximalen-Plaque-Indexes) zeigten, sich bei Patienten mit ausgeprägterer Systemerkrankung eine erhöhte Rate fehlender Zähne, eine im Durchschnitt größere Parodontaltaschentiefe sowie eine stärkere Entzündungsreaktion im Gingivabereich [gemessen anhand des Sulcusblutungsindexes (SBI)]. Die Schwere der Parodontalläsionen korrelierte mit Veränderungen im Spektrum der Immunglobuline, insbesondere einer Erhöhung der γ-Immunglobulin Fraktion, sowie der C4-Komplementfraktion. Stärker ausgeprägte Symptome der Immunkomplexvaskulitis mit der dann auch häufiger durchgeführten, immunsuppressiven Therapie scheinen für die erhöhte Manifestationsrate oraler Läsionen sowie Parodontalerkrankungen bei Patienten mit schwerer SLE verantwortlich zu sein. Forty-six patients with systemic lupus erythematous underwent thorough dental examination to determine the frequency and severity of oral lesions and periodontal diseases. According to clinical criteria, disease was classified as severe (n=26) or less severe (n=20). The overall rate of mucosal involvement in the studied patients was 48% — from 54% in patients with severe disease, 40% in those with less severe disease. Patients with severe disease were found to have a higher rate of tooth loss and an increased rate of gingival inflammation. The severity of periodontal lesions correlated with alterations in the immunoglobulin pattern, particularly with an increase in gamma-immunoglobulins. Thus it is suspected that complex immunodysregulation in combination with immunosuppressive therapy is responsible for the high rate of oral and periodontal lesions in patients with systemic lupus erythematosus.

Strip ostectomy and radical ostectomy in the treatment of craniosynostosis: an experimental animal study

In an experimental animal study using rabbits, growth phenomena were simulated which are comparable to craniosynostosis in humans. The radiological and histological findings after surgical management of these artificial craniosynostosis by means of strip ostectomy or radical ostectomy were compared with the findings obtained in control animals. Following strip ostectomy, bone defects were rapidly filled by the formation of suture-like structures. After radical ostectomy, structures consisting of connective tissue dispersed among islands of ossification were preserved over a considerable period of time, making it possible for the calvarium to adapt to the fast-growing brain. In contrast to strip ostectomy, after radical ostectomy growth of both the neurocranium and the viscerocranium, as well as the total sagittal growth of the skull, were almost identical to the corresponding growth in the control animals.

The ITI Dental Implant System

The ITI Dental Implant System is a unique, single-stage implant with research of 20-years duration. The technique, developed by Schroeder and coworkers, was designed to simplify the surgical and restorative aspects of implant therapy for both the patient and the clinician. This article describes the system, its advantages over two-stage systems, and indications for its use.