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Biomedical subjects

J Zöller

Publications and source records attributed to J Zöller.

At least 19 recordsLinked to original sources
PubMed2002

[Trans-facial distraction of the facial skull at the LeFort III level].

BACKGROUND: Several craniofacial deformities and syndromes feature hypoplasia of the midface skeleton. Until now different treatment options were based primarily on a modified LeFort III osteotomy: (1) the conventional LeFort III osteotomy with bone transplantation and intraoperative osteosynthesis, (2) distraction using subcutaneous distraction devices fixed on both sides at the os zygomaticum, and (3) bone distraction using a rigid external distraction device (RED distractor), which is fixed to the skull and pulling at the maxilla or the upper teeth. METHODS AND RESULTS: A modification of the distraction technique using the RED distraction device is presented. The tensile forces are applied to the ramus infraorbitalis or the apertura piriformis, and the tensile wires penetrate through the skin laterally to the nose. By using this new approach near the center of rotation or the center of resistance, optimal control of the vector of distraction is guaranteed. With sufficient distraction of the midface, overcorrection of the os zygomaticum can be avoided. Clinical data of seven patients are presented. DISCUSSION: Due to the good clinical results, external transfacial distraction with tensile forces pulling at the apertura piriformis seems to improve the treatment of these complex facial deformities.

Acrocephalosyndactylia↗
PubMed2001

Standardized evaluation and documentation of findings in patients with craniosynostosis.

Surgical correction of craniosynostosis is usually performed according to standard procedures. However, a standard for clinical examination and report of findings for patients with craniosynostosis does not exist as yet. To compare findings from different hospitals, a documentation system was developed by a national craniosynostosis group. This system comprises a two-page document, clinical photographs, radiographs, CT scans, anthropometric measurements and molecular genetic findings. Data from craniosynostosis patients collected from participating hospitals are stored in a database, which facilitates online access.The documentation system was developed in cooperation with the group during 3 years since 1996. It was evaluated as being practicable and reliable and enables a comparability of findings reported in different hospitals. Molecular genetic analysis was found to support the investigation of patients with craniosynostosis and should therefore be integrated in the clinical evaluation. Copyright 2001 European Association for Cranio-Maxillofacial Surgery.

Journal Article↗
PubMed1998

Possibilities and developments of intraoperative image-guided surgery in craniofacial surgery.

The standardised operational techniques of fronto-orbital osteotomy and the various modifications used today make it possible to perform extensive surgery for the treatment of craniofacial malformations and advanced tumours in this region, while also allowing for a good extra- and intracranial view. Osteotomies and resections in areas of the skull base that are normally hard to reach have been considerably facilitated and the operational risk has been lowered. Our aim is to achieve a further reduction of the operational risks and of the post-surgical morbidity rate through the use of techniques of computer-assisted surgery. Especially in the area of the complex anatomy of the skull base, use of the systems for the purpose of orientation and realisation of operational planning as well as for the control of how radical a tumour resection needs to be, have proved quite successful. Meanwhile, we have acquired experience in more than 100 clinical applications of mechanical and optoelectronical navigation systems. However, it is not possible to make changes to the presurgical data. Also, the flexibility of the system is still somewhat limited. By introducing a new referencing system, the flexibility and possible applications of navigation have been increased. The current possibilities and indications for the use of intraoperative navigation are discussed.

Computer Simulation↗
PubMed1998

[Long-term outcome after corrective surgery of the neuro- and viscerocranium of patients with simple and syndrome-related premature craniosynostosis].

A retrospective and partly prospective study was conducted to analyse both clinically and cephalometrically the craniofacial growth pattern of patients with isolated and syndrome-related premature craniosynostosis after standardized fronto-orbital and midface advancement. The file data of 293 children with fronto-orbital advancement were evaluated over an average period of 4.4 years. In addition, lateral teleradiographies of 117 patients from this group were cephalometrically analysed. Moreover, late results of 36 children and 8 adults with midface-advancement with an average follow-up period of 4.5 years were assessed. In contrast to linear craniectomy and so-called lateral canthal advancement, in only 8.2% of cases (24 out of 293 patients) were relapses requiring reoperation found in this study after fronto-orbital advancement. The evaluations indicate that with simple forms of craniosynostosis such as trigonocephaly and plagiocephaly predominantly very good or good growth can be observed. Cephalometric evaluation confirmed the limited potential of growth in the area of the anterior skull base and in the midface in the presence of syndrome-related faciocraniosynostoses. In such cases the cephalometrically confirmed maxillary hypoplasia, which increases in severity in the following order of syndromes 'Saethre-Chotzen-Crouzon-Apert-Pfeiffer', could be influenced only to a limited degree by fronto-orbital advancement. For this reason midface advancement is of secondary importance in children with very severe anomalies. In the present evaluation, a high rate of relapse of midfacial hypoplasia was to be found in children and adolescents after this operation in accordance with other references. Therefore, the indication for Le Fort III osteotomy in the growth period should be limited.

Adult↗
PubMed1998

[Results of surgical therapy of orbital abnormalities].

Dystopies of the bony orbit are caused mainly by craniosynostosis, facial clefts and encephaloceles. This article presents the results of the surgical correction of orbital hypertelorism in 24 patients. Using this operation technique, the bony interorbital distance was decreased from an average of 47.6 mm to 22.8 mm. However, the distance between the soft tissues was not reduced by the same amount as the distance between the bony orbits. The intercanthal distance decreased from an average of 58.5 mm to 44.5 mm, whereby an additional refixation of the medial palpebral ligament resulted in a reduction of the intercanthal distance to 40.8 mm. A strabismus divergens was seen preoperatively in 18 patients, postoperatively only in 8 patients. Four of the latter had to undergo operative correction of the diplopia. We conclude that the operative technique is not reserved only for complex cases of hypertelorism because it shows satisfactory functional and aesthetic results with a low complication rate.

Adolescent↗
PubMed1998

Establishment of oral mucosa phenotype in vitro in correlation to epithelial anchorage.

Cell-matrix interactions and the ordered deposition of basement membrane (BM) components are of major importance for the maintenance of tissue homeostasis in complex epithelia. This aspect was studied in vitro in a coculture system designed as an oral mucosa model. As crucial epithelial features the kinetics of proliferation, expression of site-specific keratins as well as integrin patterns in correlation to synthesis of BM components were assessed by immunohistochemistry and in situ hybridization. Comparison with non-cornified gingiva as tissue of origin revealed different stages of epithelial development, eventually leading to complete reconstruction within a time frame of 1-3 weeks. First, the initial activated stage up to 1 week was characterized by (a) high keratinocyte proliferation, (b) extended expression of the basal cell-specific keratin K5 and (c) a patchy pattern of the differentiation-specific keratins K4 and K13. Second, after 2 weeks the improvement of histoarchitecture correlated to (a) predominant K5 expression in the basal and (b) extension of K4 and K13 within the suprabasal cell compartment, (c) high expression of integrins alpha3 beta1 and alpha6 beta4 including their ligand laminin-5 and (d) accumulating deposition of basement membrane components. Third, virtually complete tissue normalization at 3 weeks was indicated by (a) restriction of K5 to the basal cell area, (b) regular suprabasal localization of K4 and K13, (c) polarization of integrins to basal and parabasal cells and (d) linear codistribution of collagen IV, "classical" laminin (-1 or -10) and laminin-5 underneath the basal cells. Thus, these organotypic cocultures represent relevant equivalents for non-keratinized oral mucosa with typical gingival differentiation features and in addition suitable models for preclinical trials such as prospective dental material testing.

Cell Differentiation↗
PubMed1998

[Squamous epithelial carcinoma in a 27-year-old patient with cellular immune defect].

Squamous cell cancer of the oral cavity mainly occurs in older patients or in patients with alcohol or nicotine abuse. Younger patients are seldom involved. The case of a 27-year-old woman with a squamous cell cancer of the right cheek will be presented. Without any risk factors, an immune defect resulting in chronic Candida infection of the oral cavity seems to be responsible for the carcinogenesis.

Adult↗
PubMed1998

[Low-dose computerized tomography of the jaw bone in pre-implantation diagnosis. Limits of dose reduction and accuracy of distance measurements].

Absorbed radiation doses delivered by computed tomography and panoramic radiography were measured in 16 anatomic sites using a head and neck phantom and thermoluminescent dosimetry. The recommended kilovoltage and scan time for dental scanning was reduced step by step, rating the quality of the low-dose scans. A reduction of up to 76% could be achieved without loss of diagnostic accuracy. Measured absorbed radiation dose ranges from 0.30 mGy (thyroid) to 29 mGy (skin) at 187.5 mAs and 1.0 mm-slices (25 mm scanning distance for maxilla, 30 mm for mandible). After reduction to 45 mAs, 0.07 mGy (thyroid) to 6.9 mGy (skin) was measured. Distance measurements on human jaw specimens were compared with corresponding CT image measurements. Average deviation was 0.1-0.3 mm. A dose reduction of 75% had no effect on the results. However, the doses of CT-scans reduced by 76% exceed by an average factor of 10 the doses of conventional panoramic radiography. Therefore, CT should be reserved for the planning of complex implant treatment in the direct vicinity of the maxillar sinus and nerves and for multiple implant insertion.

Body Burden↗
PubMed1998

Preoperative planning and intraoperative navigation in skull base surgery.

Experience with the commercially available, 3-D navigation systems Viewing Wand (ISG, Mississauga, Ontario, Canada) and SPOCS (Aesculap, Germany) in skull base surgery is presented. Having meanwhile been tested in over 60 clinical trials, the systems achieved an accuracy of < or = 2.7 mm which, at the moment, we deem sufficiently acceptable to proceed with their clinical evaluation. There was no difference in intraoperative accuracy between the mechanical and the optical navigation systems. The systems proved to be very helpful in identifying the extent of the tumours and in visualizing the proximity of vital structures. 3-D-planning, simulation and intraoperative navigation especially facilitates surgery in anatomically complicated situations, without risk of damaging neighbouring structures. The SPOCS (Surgical Planning and Orientation Computer System) revealed a considerably improved flexibility in handling and a better integration into the surgical procedure in comparison with the relatively inflexible and space-demanding Viewing Wand arm. Especially, the 'offset' function of the SPOCS offers the possibility of a virtual elongation of the instrument and thus, in combination with the on-line visualization of the corresponding images, of a 'look ahead' operation. By using computer-assisted simulation and navigation systems, we can expect quality improvement and risk reduction. More extensive and radical interventions seem possible.

Computer Simulation↗
PubMed1997

[Multi-local angiosarcoma of the oral mucosa].

A 64-year-old man presented with a bluish, livid swelling in the region of the lateral alveolar processes of all four quadrants. Evaluation and histopathological findings resulted in the diagnosis of an angiosarcoma at multiple sites. A survey of the literature and an epidemiologic review of our own patients prove this to be an extremely rare occurrence. A partial resection of the maxilla and the mandible on both sides was performed in sano. After discharge, however, a sarcoma was detected in the region of the right scapula 5 months after surgery. Therefore radiation treatment was initiated. The patient died 4 weeks later. The course confirms the poor prognosis of this tumor.

Bone Neoplasms↗
PubMed1997

[Ultrasound criteria for staging and follow-up of malignant lymphoma].

Ultrasonography is an integral part of the radiological imaging of malignant lymphomas for staging, therapy planning, monitoring, follow-up, post-therapeutic care, and detection of recurrences, as well as the diagnostic differentiation of benign lesions and metastasis of solid tumors. None of the imaging methods, including sonography, however, can safely determine the stage (UICC certainty level C4) in agreement with the pathohistological examination. Also considering the clinical appearance the sonographic criteria in the synoptic evaluation will nevertheless provide important indications for diagnosis and therapy planning. Not only changes in size and shape, but also the echogenicity (gray-scale histogram) and vascularization (color Doppler) of nodal and extranodal processes are decisive criteria for estimating the therapeutic response rates and detecting relapses.

Follow-Up Studies↗
PubMed1997

Redifferentiation of oral dysplastic mucosa by the application of the antioxidants beta-carotene, alpha-tocopherol and vitamin C.

In a clinical trial the effect of chemoprevention with beta-carotene, vitamin E and C on dysplastic tissue was studied. The study included 24 patients with oral leukoplakia and 24 patients after radical resection of a primary oral cancer. There was a reduction of increased cell kinetic parameters like the S-phase portion or the average number of nuclear-organizer regions (NOR) per cell nucleus, a decrease of the micronuclei portion and a normalization of the cytokeratin gene-expression. The general response was 97.5%. Stopping the alcohol and tobacco abuse the effect of the antioxidative vitamins on redifferentiation of the oral mucosa was more intense than by persistance of the alcohol and tobacco abuse, but a long term prevention seems to be ineffective.

Antioxidants↗
PubMed1997

[Outcome of profile-improving operations in craniofacial abnormalities].

In 52 children with craniosynostosis, we studied the effect of fronto-orbital advancement onto the forehead profile and the growth tendency of the forehead and midface. As a reference, the following kephalometric data were used: SN line. N-Spna line, SNA angle, N-tf line (as an indicator of the forehead profile) and the tf-TF line (as an indicator of the forehead size). The operation was carried out at an mean age of 10.5 months. Follow-up with X-ray control covered a period of 37.2 months on average. In patients with brachycephalus the SNA line was reduced and the post-operative growth tendency was the most unfavorable. Also the forehead profile (N-tf-line) did not become normal after the operation in patients with brachycephalus. Besides this, the increase in the forehead size indicated a new growth-tendency disorder. In all children with brachycephalus as well as in most children with oxycephalic growth tendency, sagittal midface growth was inhibited (NSA angle) while vertical midface growth was normal (N-Spna line). The success of fronto-orbital advancement was dependent on the kind of growth disorder, the location, and the age when the operation was carried out. Only early operative treatment could interrupt the pathological growth tendency even in cases with a major development disorder.

Cephalometry↗
PubMed1996

Expression of CD44 splice variants in squamous epithelia and squamous cell carcinomas of the head and neck.

Splice variants of the adhesion molecule CD44 have been described as essential for the lymphatic spread of rat tumour cells and are claimed to be involved in the metastatic spread of several human tumours. Immunohistochemistry has been used to analyse the expression pattern of CD44 standard (CD44s) and variant (CD44v) isoforms in normal and dysplastic squamous epithelia, as well as in primary and metastatic squamous cell carcinomas (SCCs), which spread predominantly by way of the lymphatic system. Frozen sections of squamous epithelia and of squamous cell carcinomas were stained with a panel of monoclonal antibodies recognizing epitopes of CD44s as well as of the variant exons v5, v6, v7, v7-v8, and v10. The stratum basale and stratum suprabasale of squamous epithelia stained with all antibodies; the stratum spinosum stained with anti-CD44v5, anti-CD44v6, anti-CD44v7-8 and anti-CD44v10; the lower layers of the stratum corneum stained with anti-CD44v5. This expression profile was seen in epithelia of the lip, the tongue, the gingiva, the hard palate, the floor of the mouth, the buccal mucosa, and the pharynx. The same pattern of expression was also noted in dysplastic epithelia, but expression of the variant exons v7, v8, and v10 was significantly downregulated in primary squamous cell carcinomas and was not detected at all in the majority of metastasis-derived specimens. Expression of CD44v5 and CD44v6, on the other hand, was mainly unaltered. Thus, epithelial cell layers representing different stages of differentiation express distinct sets of CD44 variant isoforms, where especially exons v8-v10 might be required for the maintenance of the structural integrity of squamous epithelium. Downregulation of these exons on tumour cells could indicate that they are irrelevant for tumour progression or may even hamper infiltration of surrounding tissue or of lymphatics.

Adult↗
PubMed1996

[Ultrasound diagnosis in primary staging of head-neck tumors].

The radiologic imaging methods play an important role in the precise staging as basic requirement for an effective concept of tumor therapy. The accuracy of ultrasound in the primary staging according to the TNM-classification (UICC) was therefore prospectively investigated in 260 patients with head and neck tumors of the clinical stages T1N0 to T4N3. The clinically (C1) and sonographically (C2) evaluated pretherapeutic stages were compared to the postoperative histopathologic tumor classifications. The clinical staging was correct in 75.0%, high in 7.7%, low in 17.3%, the N-stages were correct in 59.2%, high in 17.7%, low in 23.1%. The sonographic staging was apparently superior with the T-classifications correct in 92.3%, high in 7.7%, low 0.0%. The N-stages were correct in 89.6%, high in 9.2%, low in 1.2%. The accuracy of combined TN classification rose from clinical 46.5% to 84.6% by sonography. Accompanying inflammations, foregoing biopsies and tooth extractions were the main reasons for incorrect staging. Therefore, the thorough sonographic investigation performed after the clinical examination and before invasive procedures, due to little patient discomfort, good availability and high accuracy, is an excellent sectional imaging method for staging, therapy-planning and follow up of tumors of the head and neck especially of the orofacial regions.

Adult↗
PubMed1996

[Effects of chronic alcohol drinking on mouth mucosa. A morphometric study].

BACKGROUND: Chronic alcohol consumption is a major risk factor for oral and pharyngeal cancer. Besides other mechanisms a toxic effect of ethanol and/or its metabolite acetaldehyde on the oral mucosa and a resulting increased cell regeneration seem to play an important role in tumor promotion. METHODS: In the present study the effect of chronic ethanol consumption on the morphology of the oral mucosa of 20 male wistar rats that had been fed nutritionally adequate liquid diets containing 36% of total calories either as ethanol or isocaloric carbohydrates for six months was investigated. RESULTS: Morphometric analysis showed that in the ethanol rats, the size of the basal cell nuclei of the oral mucosa from the floor of the mouth, the edge of the tongue, and the base of the tongue was significantly increased (p < 0.001). The size of the basal cell layer in these rats was increased, and the stratification of the cells was altered. Mean epithelial thickness of the mucosa from the floor of the mouth was significantly reduced in the ethanol rats (p < 0.01). CONCLUSIONS: In conclusion, our results indicate that chronic ethanol consumption causes oral mucosa atrophy associated with hyperregeneration, which may result in an enhanced susceptibility of the mucosal epithelium to chemical carcinogens.

Alcohol Drinking↗
PubMed1996

[Cancer of the oral cavity in machine workers].

BACKGROUND: So far, only few studies exist which investigated the influence of occupational factors on the risk of oral cancer. PATIENTS: A case control study enrolling 100 patients with carcinomas of the oral cavity and 400 randomized control persons was performed to analyze occupational risk factors for oral cancer. RESULTS: Twenty-two percent of the tumor patients and only 8.5% of the control persons were employed as machine workers. The relative risk for squamous cell carcinoma of the oral cavity was 3.4 (K.I.: 1.7-7.0) for machine workers (adjusted for alcohol and tobacco). Single case analysis showed that 96.3% of the machine workers with oral cancer and only 17.3% of the machine workers in the control group were exposed to dust, especially metal dust (55.5% vs. 9.7%). Also the exposure to paint, lacquer, and varnish containing chromium and nickel was significantly higher in machine workers with cancer of the oral cavity than in the machine workers without cancer (29.6% vs. 10.9%). CONCLUSIONS: The findings suggest that exposition to various types of dust, especially metal dust, increases the risk of oral cancer in machine worker patients.

Adult↗