Magnetic resonance imaging in isolated sagittal synostosis.

Isolated fusion of the sagittal suture is the most prevalent form of craniosynostosis. Although the typical clinical appearance usually points the way to the right diagnosis, computed tomographic (CT) scans are still recommended as necessary tools for both the diagnosis of scaphocephaly and the preoperative planning. Because CT scans are accompanied by the biological effects of ionizing radiation, some authors have already postulated the use of magnetic resonance imaging (MRI) especially because MRI seems to be valuable for detecting intracranial anomalies compared with CT scans. Hence, we investigated the preoperative MRIs of 42 children with isolated sagittal synostosis to evaluate the frequency of brain anomalies and their therapeutic consequences.In our study, 10 patients (23.8%) showed pathologic MRI findings such as ventricular dilatation and hypoplastic corpus callosum, whereas 32 patients (76.2%) had an unremarkable MRI except a pathognomonic secondary deformation of the brain caused by the abnormally shaped skull, which was present in all patients. Seven patients showed clinically significant symptoms including papilledema or psychomotoric developmental delay; however, the clinical appearance was not predictive for pathologic MRI findings and vice versa.As the detection of brain anomalies had no influence on the surgical procedure or led to any additive therapy in our patients, we conclude that evaluation of possible pathologic brain findings does not legitimate the general use of MRI in clinically normal children with isolated sagittal synostosis.

Trigonocephaly: results after surgical correction of nonsyndromatic isolated metopic suture synostosis in 54 cases.

Children with nonsyndromatic isolated metopic suture synostosis suffer from a significant deformity of the supraorbital ridges, the temporal regions and hypotelorism. We retrospectively analyzed 54 consecutive cases of isolated nonsyndromatic metopic synostosis treated over a 14-year-period. The data were evaluated using patients' clinical records, skull radiographs in two planes, CT-scans, MRI scans and pre-/post-operative photographs. Surgery with standardized fronto-orbital advancement was performed at a median age of 11.5 months. Follow-up ranged from 4.5 months to 177.4 months, with an average of 51.9 months. The average blood loss was less than 255ml and the average post-operative length of stay was 5 days. Not a single major complication was observed except for uncomplicated dural tears in six cases. According to the classification of Whitaker, results were considered good to excellent (Category I and II) in all except one case (Category IV). As the current techniques have been standardized for routine use, surgical risks are reasonably low with no mortality or permanent morbidity. We think that the treatment of single metopic synostosis is safe with very low reoperation rates and short length of hospital stay. Overall, our results showed acceptable minor complication rates and generally satisfactory aesthetic outcomes.

Resorbable versus titanium osteosynthesis devices in bilateral sagittal split ramus osteotomy of the mandible - the results of a two centre randomised clinical study with an eight-year follow-up.

BACKGROUND: This study was conducted to compare the long-term clinical outcome of patients with jaw disproportion who had had fixation with resorbable polylactic acid containing positioning screws with those who had had titanium positioning screws in bilateral sagittal split ramus osteotomy of the mandible (BSSO). PATIENTS AND METHODS: Sixty-six patients with isolated mandibular jaw disproportion were included and divided randomly into two treatment groups (resorbable and titanium). Patients were followed for 8 years postoperatively using a standardised protocol. Material-specific complications, functional problems and clinical findings within the former operation field were documented. Treatment stability was determined by occlusion criteria. RESULTS: Thirty-four patients (54%) were followed until the end of the study. No significant differences were observed in the outcomes of patients in the two groups related to the materials used for osteosynthesis or the long-term treatment stability. During the study, no foreign body reactions were observed. CONCLUSION: This study showed that resorbable and titanium positioning screws were equally effective as fixation devices in sagittal split osteotomy. Complete resorption of the resorbable screws could not be verified because of the absence of histological examination, however, the use of resorbable positioning screws can be considered as an alternative osteosynthesis material to conventional titanium osteosynthesis devices in sagittal split osteotomy.

Haemangiopericytoma of the mandible.

Haemangiopericytomas (HPCs) found in bony structures are rare sarcomas of vascular origin. Here, we report the case of a 41-year-old female with a HPC originating in the right ramus of the mandible. After tumour staging and biopsy for histological reference the tumour was surgically removed. The surgical technique is described and therapy options of these rare cases are discussed and compared with these cases already documented. To the best of our knowledge, this is the 6th case of mandibular HPC reported in the literature.

Analgesic effects of intra-articular morphine in patients with temporomandibular joint disorders: a prospective, double-blind, placebo-controlled clinical trial.

PURPOSE: A number of reports have shown a direct analgesic effect of opioids by way of the peripheral receptors. Nevertheless, only a very few studies have reported using opioids in the temporomandibular joint (TMJ), and nearly all of them were connected to surgical patient groups. The present study was designed to evaluate the analgesic efficacy and safety of repeated intra-articular morphine applications compared with a local anesthetic and saline solution in the management of TMJ pain. PATIENTS AND METHODS: A total of 48 patients with articular pain related to the TMJ were entered in a clinical, prospective, randomized, double-blind, single-center study. The analgesic effect of repeated intra-articular infiltration with morphine (5 or 10 mg morphine sulfite), bupivacaine 0.5% (Carbostesin; AstraZeneca, London, UK), and isotonic saline solution as a placebo in the TMJ was examined. The efficiency after 3 injections of the same substance with an interval of 48 hours between each application was measured using a pain relief scale, visual analog scale, pain intensity scale, and the potential need for accessory peripheral analgesics (paracetamol). RESULTS: All patients showed, independent of the treatment group, pain relief within 60 minutes after the first injection. Patients with saline and Carbostesin reported almost complete pain recurrence before the second injection. At 1 week after the last and third injection, the 10-mg morphine group still showed a distinct effect, with 16.7% reporting complete (no pain) and 41.7% distinct pain relief. In addition, 33.3% had a poor response and 8.3% had no improvement. None of the other groups reported complete improvement; however, 25% of the patients who received 5 mg morphine had distinct pain relief, and 50% had at least poor pain relief. In the Carbostesin group, distinct improvement was reported by 8.3%, with a poor response in 41.7%, and no effect in the remaining 50%. Patients treated with saline had a poor response in 16.7%, but most (83.3%) reported no improvement 1 week after treatment. CONCLUSIONS: Independent of the applied substances, initial pain relief can be registered in the TMJ: either from the arthrocentesis effect or at least the placebo effect. Morphine at a dosage of 10 mg showed the best and most long-lasting analgesic efficiency. Morphine, in general (5 and 10 mg), and, with limitations, Carbostesin were more or less efficient for postoperative pain control but without distinct effects in the long term. With regard to our results, we can recommend intra-articular morphine application at a dose of 10 mg for pain management. Carbostesin showed no promising long-term effects.

Accuracy of template-based dental implant placement.

PURPOSE: The accuracy of a system for image-guided dental implant planning and placement based on individually fabricated oral templates was investigated in a phantom study. MATERIALS AND METHODS: The study was performed on identical phantoms of a partially edentulous mandible. In one phantom mandible (the master model), pilot boreholes for dental implants were placed. Computerized tomography image data were then acquired. Using a system for template-based dental implant placement, identical boreholes were planned on the image data and then reproduced in the 10 remaining phantom mandibles (the "slave" models). The resulting positions were compared to the positions in the master model using a three-dimensional digitizer arm. RESULTS: The mean deviation of borehole apex positions in the slave phantoms, as compared to the master phantom, was 0.50+/-0.04 mm and was below 1 mm in 29 of 30 models. The accuracy was highly reproducible, irrespective of the template used and the surgeon involved. CONCLUSIONS: The use of templates for image-guided insertion of dental implants is a method with high and reproducible accuracy.

Clinical use of navigation based on cone-beam computer tomography in maxillofacial surgery.

Image-guidance in maxillofacial surgery is based predominantly on computed tomographic (CT) images. Its main disadvantage is the considerable amount of radiation to which the patient is exposed, and dental metal artefacts. Recently, a new class of devices based on the concept of cone-beam computed tomography (CBCT) has been introduced for maxillofacial imaging, which we have investigated. In a clinical study, the first seven patients to be operated using a navigation system based on CBCT images, were evaluated. In all cases patient to image recording was uneventful and the surgical objective was reached. The guidance given by the navigation system was helpful. CBCT is an alternative to conventional CT, gives a lower dose of radiation, and costs less. Limitations in the quality of the images and the size of the field of view may restrict its use. It is suitable for image-guided surgery using a navigation system as long as the images show enough of the relevant anatomy and pathology.

Recurrent craniofacial dermatofibrosarcoma protuberans: long-term prognosis after close surgical removal.

Dermatofibrosarcoma protuberans (DFSP) is a low-grade malignant neoplasm of the dermis that rarely manifests in the craniofacial area. In this retrospective analysis, we investigated the long-term survival of 7 patients with recurrent craniofacial DFSP. This study includes all patients in our department with recurrences of DFSP between 1989 and 2006. All patients were treated by radical surgery with 1-cm free safety margin in every direction and remained in routine long-term follow-up for tumor patients. Two of the 7 patients showed a local recurrence, which was again successfully treated surgically with the same technique. Advanced reconstruction with free full-thickness skin transfers, regional flaps, and forearm flaps, respectively, was required in 5 of the 7 patients. The other 2 patients were reconstructed locally. The long-term prognosis of craniofacial DFSP can be assessed optimistically even if the tumor already reoccurred. All 7 patients included in this study are still alive and so far not suffering from local recurrence. Advanced reconstructive techniques are often required in the management of reoccurring craniofacial DFSP. Late recurrences have been reported; therefore, a long-term follow-up for these patients should be considered.

The accuracy of image guided surgery based on cone beam computer tomography image data.

OBJECTIVE: The objective of this study was to verify if accurate patient-to-image registration for precision navigation in maxillofacial surgery is possible based on cone beam computed tomography (CBCT) image data. STUDY DESIGN: A maxillary registration template was placed on a standard plastic skull phantom that was equipped with a custom made model of the maxilla and with target markers. Imaging was performed with a CBCT device (Newtom 9000 Digital Volume Tomograph (DVT), QR s.r.l., Verona, Italy) and a computed tomography (CT) scanner (Somatom 4, Siemens, Forchheim, Germany). Using an infrared navigation system (Polaris, NDI, Waterloo, Ontario), multiple pair-point registration of both image data sets and the phantom were performed. The target registration error (TRE) was evaluated. RESULTS: A total of 243 registrations were performed for either image data set. The spatial distribution of TRE on the skull showed increasing inaccuracy with growing distance from the registration markers. The average target registration error was 1.50 +/- 0.82 mm with CBCT and 1.57 +/- 0.84 mm with CT image data and did not differ significantly. Error distribution correlated strongly between CT- and CBCT-based registration. CONCLUSIONS: The overall registration accuracy based on CBCT image data was similar to CT. The strong correlation of the geometric distribution of TRE between CT- and CBCT-based measurements proves that CBCT can be equivalent to CT in image-guided maxillofacial surgery.

System design of a hand-held mobile robot for craniotomy.

This contribution reports the development and initial testing of a Mobile Robot System for Surgical Craniotomy, the Craniostar. A kinematic system based on a unicycle robot is analysed to provide local positioning through two spiked wheels gripping directly onto a patients skull. A control system based on a shared control system between both the Surgeon and Robot is employed in a hand-held design that is tested initially on plastic phantom and swine skulls. Results indicate that the system has substantially lower risk than present robotically assisted craniotomies, and despite being a hand-held mobile robot, the Craniostar is still capable of sub-millimetre accuracy in tracking along a trajectory and thus achieving an accurate transfer of pre-surgical plan to the operating room procedure, without the large impact of current medical robots based on modified industrial robots.

Neoadjuvant concurrent radiochemotherapy followed by surgery in advanced oral squamous cell carcinoma (OSCC): a retrospective analysis of 207 patients.

Locally advanced operable oral squamous cell carcinoma (OSCC) continues to be a major therapeutic challenge despite the implementation of novel multi-modal treatment approaches. To improve local and local-regional control and to allow functional reconstruction after ablative surgery, neoadjuvant protocols have been developed during the last decade implementing radiochemotherapy prior to selective surgery. In the present retrospective analysis, the results of concurrent radiotherapy with 40 Gy and low-dose cisplatin-based chemotherapy followed by major surgery are presented for n=207 patients with an OSCC of stage III or IV. The overall survival for all patients analyzed was 49.5% after 60 months and 37.0% after 120 months. Further subgroup analysis found that histopathologic N0 tumours had a significantly better 5-year and 10-year overall survival rate than N+ tumours (p=0.004). In multivariate analysis, only postoperative N0 stage was a significant predictor for a favourable outcome (p=0.004). Overall disease-free survival of the whole patient collective was 70.4% after 60 months and 62.6% after 120 months with superior 60 month and 120 month disease-free survival for T0 (p=0.018) and N0 tumours (p=0.007), which was verified by multivariate analysis (p=0.019 and p=0.055, respectively). T+ tumours inherited a 2.5-fold increased risk for the development of local or loco-regional failure (p=0.05), and N+ tumours a 6.1-fold increased risk for the development of distant metastases (p<0.001). In conclusion, neoadjuvant radiochemotherapy with 40 Gy and concurrent low-dose cisplatin monotherapy followed by selective surgery is a feasible and reliable therapy concept, which results in encouraging overall and disease-free survival rates for therapy responders and which reliably selects therapy non-responders by the histopathological assessment of the neck dissection preparation. Those therapy non-responders might profit from intensified systemic therapy approaches.

Computer-assisted condyle positioning in orthognathic surgery.

PURPOSE: Le Fort I repositioning osteotomy can affect the position of the temporomandibular joints (TMJs). During the operation, the surgeon does not have direct visual control of the TMJ. In this study, the TMJ movements in patients undergoing a Le Fort I repositioning osteotomy were recorded intraoperatively using the Surgical Segment Navigator (SSN) computer-assisted navigation system. PATIENTS AND METHODS: Unintended TMJ positions resulting from conventional repositioning of the maxillary segment were recorded. The TMJ positions in these patients were then corrected in relation to the skull base, using information obtained from the SSN. The position of the condyle was then redetermined. The accuracy of conventional and SSN-guided segment adjustments were compared in terms of their influence on TMJ position in the same group of patients. RESULTS: The median spacial malposition of the condyles without navigation was 2.4 mm. Corrective "SSN positioning" on the same patients reduced this to 0.7 mm. CONCLUSIONS: SSN allows accurate intraoperative navigation of the TMJ.

Verification of extensive bone marrow hyperplasia using magnetic resonance imaging.

PURPOSE: Bone marrow hyperplasia of the rib, lumbar spine, knee, and iliac crest is frequently encountered in patients undergoing magnetic resonance imaging (MRI) examination. In this study, we investigated extensive areas of bone marrow hyperplasia of the ascending mandibular ramus, posterior to the inferior alveolar nerve, the size of the lesions ranging from 5 to 7 cm. PATIENTS AND METHODS: In a prospective study, an orthopantomography (OPT) was performed in 15,412 patients. Seven patients in the study group (0.05%) showed extensive bone marrow hyperplasia in the ascending mandibular ramus. The diagnosis derived by means of the OPT was confirmed by T1-weighted MRI with and without fat signal suppression and was finally proved by means of the histological findings from a bone biopsy. RESULTS: This investigation shows that a T1-weighted MR image with and without fat signal suppression shows a typical heterogeneous distribution of signal intensity with a unique pattern not found in other lesions. The MRI-based diagnosis in our study group was always confirmed by means of a bone biopsy performed via a transbuccal approach. CONCLUSION: We conclude that properly selected MRI studies are by themselves adequate to diagnose these lesions and that these imaging studies supplant the need for a bone biopsy.

Template-based registration for image-guided skull base surgery.

OBJECTIVES: To evaluate whether patient-to-image registration with the use of a maxillary template is sufficiently accurate for image guided skull base surgery. STUDY DESIGN AND SETTING: In an experimental phantom study, pair-point registration of a skull phantom to its CT image data was performed with 243 different configurations of a maxillary template with markers. Then artificial skull mounted target markers were located with an infrared tracking device as used in navigation systems. RESULTS: The average target registration error was 1.57 mm in the anterior skull base (95% confidence interval, 1.53 to 1.61 mm), but 3.31 mm in the lateral skull base (95% confidence interval, 3.26 to 3.37 mm). CONCLUSIONS: Fiducial marker registration based on a maxillary template is sufficiently accurate for image-guided surgery in the anterior skull base, but not for the lateral skull base. SIGNIFICANCE: Template-based registration is an accurate yet noninvasive registration method for frontal skull base surgery.

Operative correction and follow-up of craniofacial duplication.

BACKGROUND: Anterior craniofacial duplication (diprosopus) is an extremely rare form of conjoined twins. The children share a single trunk with normal extremities and varying degrees of facial malformation. Duplication of specific structures, such as the nose (diprosopus dirrhinus), eyes (diprosopus tetraophthalmus), and ears, is possible. The authors present a case of partial facial duplication (diprosopus dirrhinus) in a male infant. METHODS: The clinical and radiographic findings and the surgical correction and follow-up are described. RESULTS: In a single surgical session, the authors were able to achieve not only a functionally but also an aesthetically acceptable result. In the postoperative course, the child showed nearly normal growth and satisfactory psychosocial and motor development. However, 40 months postoperatively, we noticed a tendency of the orbitae to diverge (i.e., toward hypertelorism). CONCLUSIONS: The surgical management of complex craniofacial malformations such as diprosopus needs a precise morphologic analysis of the patient's deformity followed by a clear treatment plan. A staged reconstructive approach is carried out to coincide with facial growth patterns and brain and eye function. If the interorbital distance in our patient increases progressively, a second operation for reduction of the interorbital distance may be necessary.

Inverted papilloma of paranasal sinuses.

INTRODUCTION: Inverted papilloma (Schneiderian papilloma) is a primarily benign lesion that occurs in the nasal cavity and paranasal sinuses. Clinical problems include a tendency towards local destruction, recurrence and malignant transformation into squamous cell carcinoma. Hence, complete surgical removal is the therapy of choice and a meticulous follow-up is mandatory. STUDY DESIGN: This is a review including a short introduction to the different histological types of nasal papilloma, their pathogenesis and the clinical and histopathological diagnosis. Staging systems, therapeutic approaches, and surgical concepts are discussed. RESULT: The detection and definition of factors that allow a prognosis of recurrence or malignant transformation of inverted papilloma is an active field of research. The results of studies dealing with the definition of prognostic factors, that investigated immunohistochemical methods, virus detection, molecular genetics, and histomorphological studies are discussed including our own results on the prognostic value of histology. A concept for the diagnosis, management, therapy and follow-up of inverted papilloma is proposed.

Diagnostic imaging in the management of craniosynostoses.

Craniosynostoses are the most frequent craniofacial malformations. However, with a prevalence of 3-6 cases per 10,000 live births they are amongst the rarely seen diseases and their definite diagnosis thus poses a challenge to the physician. When an abnormal calvarial configuration is detected, a radiological evaluation is necessary to characterize the deformity and to guide the corrective surgical procedure. The demand for clear diagnostic criteria is justified by the severity of the disease and the possible consequences of delayed diagnosis. In addition to the clinical signs (deformation of the head), conventional skull X-rays show typical radiological alterations and are used for basic diagnostics. Diagnostic tests that may be performed to confirm the diagnosis and assess the extent of the problem, include computed tomography (CT), 3D-CT, magnetic resonance imaging (MRI) scans, and ultrasonography. In the present review we will describe the most important clinical and radiological characteristics of craniosynostosis by means of clinical, radiological and operative situs examples.

Recurrent FGFR1 amplification and high FGFR1 protein expression in oral squamous cell carcinoma (OSCC).

Chromosomal aberrations are known to have an impact on the initiation and progression of oral squamous cell carcinoma (OSCC), but individual genes involved in OSCC pathogenesis are poorly described. To elucidate the molecular events underlying oral carcinogenesis, a set of primary OSCC were screened for distinct genetic imbalances by means of array-based comparative genomic hybridisation. For this, a DNA array was used containing 812 genomic targets including oncogenes, tumour-suppressor genes and chromosomal regions frequently altered in human neoplasms. The most frequent aberrations were amplification of MYC, EGFR, CCND1 and PIK3CA, whereas deletions affected TRAILR1 and ATM. Furthermore, a distinct high-level amplification of the fibroblast growth factor receptor 1 (FGFR1) locus was detected in two cases. Detailed FISH analysis on OSCC tissue microarray sections revealed amplification prevalence for FGFR1 of 17.4% (16/92). Furthermore, FGFR1 protein analysis by immunohistochemistry on a TMA containing 178 OSCC found a high FGFR1 expression in tumours of early t-stadium and UICC stage (T1/2 vs. T3/4: p=0.002; SI-II vs. S III-IV: p=0.048). Our results indicate that an increase in FGFR1 expression contributes to oral carcinogenesis at an early stage of development.