Mandibular cortical shape index in non-standardised panoramic radiographs for identifying patients with osteoporosis as defined by the German Osteology Organization.

The aim of this prospective controlled study was to determine the validity of the mandibular cortical shape index (CI) on panoramic radiographs in distinguishing patients with osteoporosis as defined by the German Osteology Organization (Dachverbands der Deutschsprachigen Osteologischen Fachgesellschaften, DVO). The study group contained 50 patients (33 female, 17 male, mean age: 74.9 years), who had a high risk of osteoporosis. 50 young patients (33 female, 17 male, mean age: 37.9 years) with no anamnestic evidence of osteoporosis served as control. Three blinded observers evaluated panoramic views of the study and the control group in a mixed manner regarding the mandibular cortical shape index. The study group underwent bone mineral density measurement using dual energy X-ray absorptiometry and received a diagnosis according to the Organization's guidelines (normal, osteopenia, osteoporosis). The CI showed a high sensitivity of 72.2% and a high specificity of 93.9% with a highly significant predictive value (Chi-square = 22.96, p < 0.001), while the observer's agreement was moderate (kappa = 0.47). We concluded that patients with a cortical shape index of the category assessed as "severe" on non-standardised panoramic radiographs have a higher risk of suffering systemic osteoporosis. The CI in panoramic radiographs is a good screening tool, which could be implemented in the routine assessment of panoramic radiographs in elder patients.

Long-term donor-site morbidity after microsurgical fibular graft: is there a difference between the medial approach and the lateral approach?

PURPOSE: Microvascular fibula harvesting for osseous reconstruction is a valuable aid in maxillofacial surgery. We assessed whether the lateral and the medial harvesting techniques differed with respect to long-term donor-site morbidity. MATERIALS AND METHODS: We conducted a retrospective cohort study of patients who had undergone free fibula harvesting at the University Medical Center Hamburg-Eppendorf, Hamburg, Germany, between 1987 and 2008. The primary predictor variable was the surgical approach. The primary and secondary outcome variables were the American Orthopaedic Foot & Ankle Society score and the result of the Short Form 36 Health Survey on quality of life, respectively. Other variables were age, gender, harvest length, operation time, and specific impairments and surgical complications. Statistical analysis was performed with SPSS, version 14.0 (SPSS, Chicago, IL); P < .05 was considered significant. RESULTS: The 42 patients had a mean age of 55.5 years. The mean follow-up period was 81 months (range, 7-174 months). In the medial group, the mean American Orthopaedic Foot & Ankle Society score was 94.4 points and the total number of impairments was 34, as compared with 85.6 points and 46 impairments, respectively, in the lateral group. This tendency for less morbidity with the medial approach was only found in female patients. The Short Form 36 scores were not statistically different between the 2 surgical approaches. CONCLUSIONS: The medial approach led to less functional impairment of the foot and ankle. Our results support the medial approach as a viable alternative, especially in women, but only in cases when a skin paddle is not necessary.

Primary implant stability after maxillary sinus augmentation with autogenous mesenchymal stem cells: a biomechanical evaluation in rabbits.

OBJECTIVES: To mechanically evaluate the effect of transplantation of precultured preosteoblasts derived from autogenic adult mesenchymal stem cells (aMSC) for experimental sinus floor augmentation on primary dental implant stability in comparison with conventional augmentation procedures in rabbits. MATERIAL AND METHODS: After experimental sinus floor augmentation with a synthetic bone substitute, autogenous bone transplantation or osteoblast precursor cells, the primary stability of implants inserted in the edentulous part of the upper jaw of New Zealand White Rabbits was examined. Mechanical evaluation was performed by determination of insertion torque values (Osseocare(™) ), percussion testing (Periotest(™) ), resonance frequency analysis (Osstell(™) and scanning laser Doppler vibrometer) and measurement of extraction forces. RESULTS: Evaluation of mechanical properties with percussion testing and resonance frequency analysis with Osstell(™) revealed slightly higher primary stability of the stem cell group whereas the scanning laser Doppler vibrometer and measurement of pull-out forces showed no significant difference to the bone substitute group. Transplantation of autogenous bone graft resulted in the highest primary implant stability. CONCLUSIONS: The three examination modalities proved suitable for the determination of primary implant stability. The experimental maxillary sinus floor augmentation with precultured osteoblast precursor cells from autogenic stems cells clearly enhanced the primary stability of implants compared with the unaugmented sinus and lead to comparable primary mechanical properties to bone substitutes in rabbits. In comparison with the autogenous bone graft stability enhancement by stem cell transplantation declined.

Metastases in odontogenic cysts: literature review and case presentation.

Malignant tumors in the oral cavity are relatively rare. About 5% of all malignant growths in the body are localized in the oral cavity. The vast majority of oral malignancies are primary tumors with squamous cell carcinoma being the most frequent and sarcomas occurring very seldom. Secondary tumors caused by hematogenous spread arising from a tumor localized elsewhere in the body are extremely rare. About 1% of all oral cancers are metastases to the jawbones and the surrounding soft tissues. Metastases to the jaws are mainly caused by malignant tumors of the breast, lung, kidney, bone, and colon. They occur in the late state of the disease and are regularly detected by staging examinations including scintigraphy. Even more rare are metastases into odontogenic cysts. Odontogenic cysts include dentigerous cysts, periapical or radicular cysts, and the keratocysts-nowadays declared as keratocystic odontogenic tumor. The incidence of odontogenic cysts is about 10% to 15% of all oral biopsies and therefore general dentists are frequently faced with these types of lesions. The aim of this study was to review the literature regarding metastasis into odontogenic cysts and to further highlight this rare entity with the help of a clinical case.

Clinical follow-up examination of surgically treated fractures of the condylar process using the transparotid approach.

PURPOSE: The surgical approaches for the open treatment of condylar process fractures have been controversial. In our study, we evaluated the morbidity of the transparotid approach during 2 years of follow-up. PATIENTS AND METHODS: A total of 48 patients with condylar process Class II and IV fractures according to classification of Spiessl and Schroll, were included in the present study. Of the 48 patients, 16 were female and 32 male. The patient age range was 16 to 79 years (average 36.52). All patients were treated using the transparotid approach, with rigid internal fixation using miniplates. Follow-up examinations were performed for a minimum of 6.5 months and a maximum of 25 months (average 12.16) after surgical treatment. At the follow-up examination, the patients completed the Mandibular Function Impairment Questionnaire, and the examiner completed the Helkimo index. X-rays taken before, directly after, and 6 months after surgery were compared. RESULTS: None of our patients had problems with wound healing; 2 patients developed a fistula of the parotid gland; and 4 patients developed palsy of the facial nerve that was completely reversible after 6 weeks. The results of the Mandibular Function Impairment Questionnaire and the Helkimo index revealed only a few subjective and objective problems after 6 months. CONCLUSIONS: The transparotid approach to condylar process fractures is most appropriate for strongly displaced Class II fractures. Especially for very old patients with dementia, for whom maxillomandibular fixation is contraindicated, this approach is very appropriate. Another benefit to this type of patient is the short operating time, with an average of 45 minutes.

Impact of rhBMP-2 on regeneration of buccal alveolar defects during the osseointegration of transgingival inserted implants.

OBJECTIVE: New approaches to enhance vertical bone regeneration in clinically relevant implant models are needed. Therefore, we analyzed the impact of recombinant human bone morphogenic protein 2 (rhBMP-2) on the healing of large buccal alveolar defects during osseointegration of transgingivally inserted implants. STUDY DESIGN: Twenty-four dental implants were inserted transgingivally in the mandibles of 6 labrador/golden retriever cross-bred dogs. Before implantation, a standardized buccal bone defect was created and refilled with either calcium phosphate as a carrier containing rhBMP-2 or calcium phosphate alone. Either ceramic abutments that enabled immediate implant loading or healing distance collars to prevent loading were mounted. Sixteen weeks after intervention, bone implant units were analyzed by radiofrequency analysis and histomorphometry. RESULTS: In total, 14 implants (58.3%) were available for further analysis. The mean depth of the bone defects, the gain of regenerated bone, the vertical osseointegration of the implants, and the bone-to-implant contact in the newly formed bone were slightly greater in the rhBMP-2-containing samples. In contrast, the osseointegration in the preexisting bone was even superior within the non-rhBMP-2-treated specimen. However no differences were statistically significant. CONCLUSIONS: When rhBMP-2-conducted bone regeneration was compared with control samples, no significant differences of newly formed bone were found at the bone-implant interface. The amounts of rhBMP-2 applied do not seem suitable to enhance implant osseointegration in large buccal defects.

Primary osteoplasty using calvarian bone in patients with cleft lip, alveolus and palate.

PURPOSE: The results of primary bone grafting in terms of initial cleft width, existence or absence of a lateral incisor and scar formation in the donor area are compared. METHODS: After primary osteoplasty with calvarian bone at an average age of 24 months (4-56 months) radiographic assessment was carried out in 31 patients with 40 alveolar clefts. The bone formation in the grafted area was assessed using dental radiographs taken at 66 months on average (13-114 months) after primary bone grafting. According to the Abyholm classification patients were assigned to 4 groups (indices I-IV) with indices I and II being rated as a success. RESULTS: We observed success (indices I and II) in 76% and poor results (index IV) in 14%. The causes for the poor results were an alveolar cleft width of 11-12 mm in three cases, an extraction of a decayed deciduous tooth 17 months after bone grafting in one case and a traumatic transplant loss in another case. The non-existence of a lateral incisor and a broad cleft are related to poor results. CONCLUSION: Based on the results presented, primary bone grafting using calvarial bone seems to be a promising alternative in bridging narrow alveolar defects. This method allows early intervention at an age in which children do not recognize themselves as cleft patients. The preservation of the deciduous teeth is equally important regarding their functional stimulus for bone development.

Intraoperative cone-beam computed tomography in oral and maxillofacial surgery using a C-arm prototype: first clinical experiences after treatment of zygomaticomaxillary complex fractures.

PURPOSE: To describe the first clinical applications of intraoperative cone-beam computed tomography with an integrated flat-panel detector in oral and maxillofacial surgery after surgical treatment of zygomaticomaxillary complex fractures PATIENTS AND METHODS: Nine cone-beam computed tomography datasets of patients with zygomaticomaxillary complex fractures were intraoperatively acquired using a mobile isocentric C-arm (PowerMobil; Siemens Medical Solutions, Erlangen, Germany), including a flat-panel detector. Datasets based on 400, 200, and 100 fluoroscopic images were performed with different tube currents (4.6 mA, 3.3 mA, 2.3 mA, 1.2 mA, and 0.5 mA) and a current tube voltage of 100 kV. Postprocessing resulted in 15 different datasets available for comparison with corresponding preoperative computed tomography datasets. Four oral and maxillofacial surgeons and 2 experienced radiologists evaluated each dataset regarding noise, transition, and the delimitation of landmarks. RESULTS: All examinations were successfully performed. Reconstructed datasets showed high-resolution images of all midfacial osseous structures in near-computed tomography quality. Regarding high-contrast structures, detailed analyses of datasets acquired in this study suggest that the parameters 400 projections, 1.2 mA, and 100 kV are sufficient. In terms of soft-tissue visualization, a higher level of mA seems preferable. CONCLUSIONS: The tested prototype predicts a new era in cone-beam computed tomography imaging. The integration of a flat-panel detector will overcome the limitations of current available systems. The size of the field of view is increased allowing regularly the visualization of the whole facial skeleton. Particularly in cases of open reduction of unilateral fractures, the assessment of symmetry is of clinical value.

Conditioning of myocutaneous flaps.

PURPOSE: The improvement of the ischaemic tolerance of myocutaneous flaps is of clinical importance and hence the subject of numerous investigations. METHODS: In an attempt to increase the ischaemic tolerance, 20 myocutaneous flaps (rectus abdominis muscle) in pigs were elevated and perfused with various, established solutions prior to the onset of ischaemia. The flaps were elevated, utilizing the superior epigastric vessels as the pedicle. Ten flaps were flushed with the University of Wisconsin solution, five with the Euro-Collins solution and the last five with a Ringer-Lactate solution, prior to the 6h long, normothermic ischaemia. On the day of operation, the first, third, fifth, seventh and tenth postoperative day clinical examinations and thermography were performed as well as biopsies. Additionally, on the tenth postoperative day, the rate of necrosis was determined morphometrically as the average of three measurements. RESULTS: Ten days after surgery, the flaps pretreated with the University of Wisconsin solution displayed a vital surface area of 89%, the Euro-Collins solution 23% and the Ringer-Lactate solution 14%. Histologically, muscle tissue proved to be more susceptible to ischaemia than skin. CONCLUSION: Regarding the rectus abdominis flap in a pig model, the University of Wisconsin solution proved superior in the prevention of ischaemic injury compared with the Euro-Collins solution and Ringer Lactate. In accordance with the literature, muscle tissue proved to be more susceptible to ischaemia than skin in our study.

Distraction osteogenesis in secondary microsurgical mandible reconstruction: report of seven cases.

INTRODUCTION: Fibula, ilium and scapula are the preferred donor areas for vascularised bone grafts. For secondary mandibular reconstruction, however, compromises often have to be made as a result of the poor quality of the covering soft tissue and recipient vessels especially in irradiated patients. Callus distraction osteogenesis is a complementary method for optimising the intermaxillary relationship and the facial profile from an aesthetic point of view. MATERIALS AND METHODS: Thirteen distractions were performed in seven patients following microsurgical mandibular reconstruction over a period of 4 years, all by the same surgeon. Intra-oral distraction devices were predominantly applied. After a 7-day healing period, the callus distraction was begun, involving two advisements per day of 0.5mm each. The distraction devices were removed after a consolidation phase of 4-5 months. RESULTS: Ten of the 13 distractions were uneventful with an average bone lengthening of 20mm, retained after a follow-up time of 6-47 months (average 27 months). The intermaxillary relationship and the facial profile were improved in all cases. Distraction plate fractures, screw loosening or absence of new bone formation were the complications encountered in the other three patients. CONCLUSION: Regarding the high complication rate, a successful outcome cannot be expected with greater certainty. Thus the indication should be stringent when including this procedure within the possible treatment alternatives available to the clinician.

Clinical implementation of a multidirectional, angular stable osteosynthesis system in maxillofacial traumatology.

AIM: To investigate whether a multidirectional, angular stable osteosynthesis system is suitable for the treatment of mandibular fractures and to compare it with well established available systems. MATERIAL AND METHODS: Following preliminary testing in an animal model, the multidirectional angular stable system TiFix 2.3 obtained from Litos (Hamburg, Germany) was utilised for internal fixation of 39 mandibular fractures. These involved four symphyseal fractures, 17 parasymphyseal, 16 of the angle of the mandible and two comminuted fractures. The surgical and postoperative course was closely scrutinised. Radiographs were taken after 6 months and all plates removed under local anaesthesia. Photographs were taken intraoperatively and the plates and surrounding soft tissues were salvaged for histological analysis. Additionally, these operations were compared with treatment of equivalent fractures which were treated with conventional, non-angular stable systems. The relative costs have also been evaluated. RESULTS: In 33 of the 39 fractures one TiFix plate sufficed for osteosynthesis. The plate most often used was a 2-hole plate which was applied in 25 (55.5%) fractures, followed by the 4-hole plates used in 16 (35.5%) fractures. In two comminuted fractures, four 6-hole plates were used (9%). In 17 patients the operation lasted less than 30 min, in 20 patients less than 60 min, in two less than 120 min. In all cases, the operations were shorter, and due to the plates' dimensions fewer screws had to be used, thus reducing the costs. DISCUSSION: This angular stable system enabled reduction of the amount of the implant material. Also reduced were the operation time and the cost of the procedure. Furthermore, in the future it will allow smaller access incisions and better preservation of the soft tissue integrity.

Mechanical aspects of a multidirectional, angular stable osteosynthesis system and comparison with four conventional systems.

BACKGROUND: Following open reduction, internal fixation of fractures of the mandible is predominantly achieved using plates and screws. Today, a multitude of osteosynthesis systems are available on the market. One therapy modality, primarily developed for orthopaedic surgery, is using angular stable osteosynthesis plate systems. The dominating principle of these is the bond between screw and plate following insertion. This principle of an "internal fixateur" results in a more stable fixation of the fragments associated with less compression of the bone surfaces. MATERIAL: A new multidirectional osteosynthesis system (TiFix=Smartlock, Hamburg - Germany) was modified to fit the maxillofacial region and compared with four other well established osteosynthesis systems developed by Mondial, Medicon, Synthes, Leibinger-Stryker, one of these (Unilock by Synthes) being also angular stable. The resistance to deformation in varying directions was investigated following fixation in four different materials. RESULTS: The TiFix system proved more resistant to deformation even when mounted with fewer screws than the non-angular stable systems. CONCLUSION: This system results in greater stability even when fewer screws are used. For the clinician this means smaller access incisions, less soft tissue trauma, better aesthetic results, decreased duration of operation and a reduction of costs.

The medial approach to the fibula: a feasible alternative.

PURPOSE: Since the first harvesting of a microsurgical fibula in 1974 by Ueba and in 1975 by Taylor, using the fibula for osseous reconstruction has proven to be a valuable approach. The harvesting technique, which has been refined by subsequent investigators, has become increasingly standardized, today providing a clear, reproducible method. The procedure involves elevating the fibular graft from lateral, choosing the shortest route to reach the fibula. One disadvantage of this approach is that the bone often obstructs visualization of the vascular pedicle, which lies medially, promoting unintentional injury. In addition, this method is associated with some donor site morbidity, prompting further investigations into accessing the fibula. Here we present an alternative approach for harvesting the fibula and highlight the pros and cons of each approach. PATIENTS AND METHODS: Between 1999 and 2006, a total of 38 microsurgical (23 for the mandible, 9 for the extremities, and 6 for the maxilla) fibula grafts were harvested through the medial approach. RESULTS: In all cases, the patency of the posterior tibial, peroneal vessels, and the tibial nerve could be visualized. Two flaps failed (both mandible, for a success rate of 94.7%). No ischemic or wound healing complications of the lower limb were observed. CONCLUSIONS: The medial approach for harvesting the fibula is a feasible alternative to the lateral approach and provides the surgeon with a comparable likelihood of success. If for some reason access from the lateral approach is contraindicated, then the medial route should be considered.

Major mandibular surgical procedures as an indication for intraoperative imaging.

PURPOSE: This study investigated 3-dimensional (3D) imaging with intraoperative cone beam computed tomography (CBCT) in major mandibular reconstruction procedures. PATIENTS AND METHODS: The study group was comprised of 125 patients (83 males, 42 females) admitted for surgical treatment of the mandible. The patients ranged in age from 3 months to 91 years (average age, 40.72 +/- 22.843 years). Surgical procedures of the mandible were subdivided into repair of body fractures (17 patients), angle fractures (21 patients), condylar fractures (14 patients), and multiple fractures (30 patient). In addition, the study group included 21 patients undergoing orthognatic surgery and 22 undergoing reconstructive surgery on the mandible. Intraoperatively, 3D images were generated with a mobile CBCT scanner (Arcadis Orbic 3D; Siemens Medical Solutions, Erlangen, Germany). RESULTS: During open reduction of mandibular fractures, not all fracture sites can be readily exposed for direct visual control. For example, the lingual cortical bone of the mandible is difficult to assess intraoperatively. This structure and others can be effectively visualized using the 3D mode of CBCT. Furthermore, screw placement can be evaluated, specifically in insertions near the alveolar nerve. The intraoperative acquisition of the data sets is uncomplicated, and the image quality is sufficient to allow evaluation of the postoperative result in all cases. CONCLUSION: Intraoperative CBCT has proven to be a reliable imaging technique for providing visual control during major mandibular procedures.

Retrospective assessment of the peri-implant mucosa of implants inserted in reanastomosed or free bone grafts from the fibula or iliac crest.

PURPOSE: To investigate the susceptibility of implants to inflammation following autogenous bone transplantation and to evaluate whether various factors affect outcomes. MATERIALS AND METHODS: This retrospective cross-sectional clinical investigation involved patients who were treated between the years 1994 and 1996. The donor site, mode of transplantation, primary disease, gender, smoking habits, and age were evaluated with respect to outcomes. Clinical and radiologic assessments were the basis for the classification into 3 categories: (1) no inflammation, (2) mucositis, and (3) peri-implantitis. Lost implants were also noted. The data were evaluated statistically to determine whether significant differences existed. RESULTS: Forty-three patients (23 men and 20 women) were involved in this retrospective study. These patients received a total of 216 oral implants over a follow-up time of 8 to 10 years. Depending on the type of reconstruction, rates of peri-implant inflammation between 9% and 38% were observed. For mucositis, rates of 16.3% to 24.1% were seen, and 30% to 70.9% of sites showed no inflammation. CONCLUSION: High rates of soft tissue inflammation adjacent to implants were observed. The choice of donor site in conjunction with the mode of transplantation seemed to influence the development of peri-implant inflammation. The microsurgically reanastomosed fibula seemed most resistant to inflammatory processes, followed by the microsurgically reanastomosed iliac crest, free iliac crest, and free fibula. No significant differences could be observed for primary disease. These findings should be taken into consideration prior to surgery and when establishing individual recall systems.

Short tandem repeat polymorphism in exon 4 of esophageal cancer related gene 2 predicts relapse of oral squamous cell carcinoma.

Short tandem repeat (STR) polymorphisms in exon 4 of esophageal cancer related gene 2 (ECRG2) are a prognostic marker for squamous cell carcinoma (SCC) of the esophagus. The aim of the present study was to correlate these STRs with clinical outcome of the similar tumor type oral squamous cell carcinoma (OSCC). DNA of 81 patients that underwent complete surgical resection of OSCC was analyzed for STRs TCA3/TCA3, TCA3/TCA4 and TCA4/TCA4 in exon 4 of ECRG2 by PCR, capillary electrophoresis and DNA sequencing. ECRG2 STR TCA3/TCA3 were found in 45 (56%), TCA3/TCA4 in 33 (41%) and TCA4/TCA4 in 3 (3%) patients. TCA3/TCA3 was significantly associated with reduced relapse-free survival of OSCC, compared with TCA3/TCA4 and TCA4/TCA4 genotypes (P<0.05; log-rank test). TCA3/TCA3 STR was independent prognostic factor determined by multivariate Cox regression analysis (p<0.05). STR polymorphism TCA3/TCA3 in exon 4 of ECRG2 is associated with poor relapse-free survival in surgically completely resected OSCC patients and might be a potential prognostic marker.

3D C-arm as an alternative modality to CT in postmortem imaging: technical feasibility.

OBJECT: The aim of our study was to demonstrate the image quality of the new device using human cadavers, extending the horizon of available imaging modalities in forensic medicine. MATERIALS AND METHODS: Six human cadavers were examined, revealing C-arm data sets of the head, neck thorax, abdomen and pelvis. High-resolution mode was performed with 500 fluoroscopy shots during a 190 degrees orbital movement with a constant tube voltage of 100 kV and a current of 4.6 mA. Based on these data sets subsequent three-dimensional reconstructions were generated. RESULTS: Reconstructed data sets revealed high-resolution images of all skeletal structures in a near-CT quality. The same image quality was available in all reconstruction planes. Artefacts caused by restorative dental materials are less accentuated in CBCT data sets. The system configuration was not powerful enough to generate sufficient images of intracranial structures. CONCLUSION: After the here-demonstrated encouraging preliminary results, the forensic indications that would be suitable for imaging with a 3D C-arm have to be defined. Promising seems the visualization local limited region of interest as the cervical spine or the facial skeleton.

The biosurgical wound debridement: experimental investigation of efficiency and practicability.

The use of maggot therapy is experiencing a revival in the treatment of problem wounds. Although this alternative therapy is ancient, little scientific research has been aimed at standardizing this therapy. The purpose of our investigation was to determine the debridement efficiency of this therapy, i.e., to compare the use of freely crawling maggots with maggots in a Biobag and to estimate the amount of maggots needed for debridement. We designed an artificial wound model and investigated the rate of decomposition of porcine tissue. Two application alternatives were compared, each being carried out either for 3 or for 4 days, (1) maggots that were allowed to crawl freely over the substrate and (2) maggots confined to a Biobag with no direct contact with the wound. We found that a single maggot was capable of debriding approximately 0.15 g of dead tissue per day. Assuming an absolute difference of <0.05 g per day and maggot as clinically irrelevant, the debridement efficiency of free maggots appears to be similar to those in a Biobag. We were able to determine for the first time the average debriding ability of maggots and thus provide the clinician with data that may help to optimize the maggot therapy by facilitating more exact approximations of the number of maggots needed. Furthermore, the result that the maggots in the Biobag are equal to free maggots in their debriding efficiency will promote its use, especially with respect to the time saved for changing of the dressings. Also, we were able to show that no direct contact is necessary between the maggots and the wound surface, proving that the mechanical crawling effect appears to be neglectable. Because significantly more tissue was metabolized after 4 than after 3 days, application intervals of 4 days appear more appropriate than those of 3 days.

Cervical soft tissue imaging using a mobile CBCT scanner with a flat panel detector in comparison with corresponding CT and MRI data sets.

OBJECTIVE: The aim of this study was to evaluate soft tissue image quality of a mobile cone-beam computed tomography (CBCT) scanner with an integrated flat-panel detector. STUDY DESIGN: Eight fresh human cadavers were used in this study. For evaluation of soft tissue visualization, CBCT data sets and corresponding computed tomography (CT) and magnetic resonance imaging (MRI) data sets were acquired. Evaluation was performed with the help of 10 defined cervical anatomical structures. RESULTS: The statistical analysis of the scoring results of 3 examiners revealed the CBCT images to be of inferior quality regarding the visualization of most of the predefined structures. Visualization without a significant difference was found regarding the demarcation of the vertebral bodies and the pyramidal cartilages, the arteriosclerosis of the carotids (compared with CT), and the laryngeal skeleton (compared with MRI). Regarding arteriosclerosis of the carotids compared with MRI, CBCT proved to be superior. CONCLUSIONS: The integration of a flat-panel detector improves soft tissue visualization using a mobile CBCT scanner.