Value of intra- and post-operative cone beam computed tomography (CBCT) for positioning control of a sphenopalatine ganglion neurostimulator in patients with chronic cluster headache.

INTRODUCTION: The objective of this study was to determine whether postoperative control of the neurostimulator placement within the pterygopalatine fossa (PPF) by means of 3-dimensional (3D) cone beam computed tomography (CBCT) was of therapeutic relevance compared to intraoperative CBCT imaging alone. MATERIAL AND METHODS: Immediately after implantation of the sphenopalatine ganglion (SPG) neurostimulator, intraoperative CBCT datasets were generated in order to visualize the position of the probe within the PPF. Postoperatively, all patients received a CBCT for comparison with intraoperatively acquired radiographs. RESULTS: Twenty-four patients with cluster headache (CH) received an SPG neurostimulator. In 4 patients, postoperative CBCT images detected misplacement not found in intraoperative CBCT. In 3 cases, electrode tips were misplaced into the maxillary sinus and in 1 case into the apex of the PPF superior to the suspected location of the SPG. Immediate revision with successful repositioning within 3 days was done in 2 patients and a deferred reimplantation in 1 patient within 6 months. One patient declined revision. CONCLUSION: We were able to demonstrate the clinical value of postoperative dental CBCT imaging with a wide region of interest (ROI) due to a superior image quality compared with that achieved with intraoperative medical CBCT. Although intraoperative 3D CBCT imaging of electrode placement is helpful in the acute surgical setting, resolution is, at present, too low to safely exclude misplacement, especially in the maxillary sinus. High-resolution postoperative dental CBCT allows rapid detection and revision of electrode misplacement, thereby avoiding readmission and recurrent tissue trauma.

Nasal position of nasotracheal tubes: a retrospective analysis of intraoperatively generated three-dimensional X-rays during maxillofacial surgery.

BACKGROUND: The aim of this retrospective investigation was to evaluate the position of the nasotracheal tube in the nose and to show its anatomical relationship with the maxillary sinus ostium. METHODS: Fifty data sets from patients who had undergone endonasal intubation were analyzed for tube positioning. There was a drop-out of eight data sets due to missing information concerning tube size and mode. Tube positioning was determined at the maxillary sinus ostium in the intraoperatively generated three-dimensional X-ray data sets. The type of tube, the tube size, and the presence of maxillary sinusitis were analyzed 30 minutes after intubation. RESULTS: The tube was positioned in the middle nasal meatus in 35 (83.3%) patients and not in the middle nasal meatus in 7 (16.7%) patients. The difference in comparison with equal distribution was significant (P <0.001). The test value was 83.3; the 95% confidence interval of the test value was 68.6 to 93.0%. Maxillary sinusitis was diagnosed as a chance finding in 17% of patients (n =7). CONCLUSIONS: The majority of nasal tubes are positioned in the middle nasal meatus. This result can be part of the answer to the question of the causal relationship between position of the breathing tube and the onset of maxillary sinusitis. The indications for prolonged nasotracheal intubation instead of orotracheal intubation or early tracheostomy should be considered carefully.

Immunohistochemical analysis of p16 expression, HPV infection and its prognostic utility in oral squamous cell carcinoma.

OBJECTIVES: Functional inactivation of p16 is an early and frequent event in the carcinogenesis of tumours of the head and neck region. However, the prognostic relevance of p16 protein expression for these tumours has been controversial. This study aims to examine immunohistochemical expression of p16 and HP virus in a large number of oral carcinomas, and possible correlation with clinical features of the tumours and survival of the patients. METHODS: Two tissue microarrays composed of 222 oral carcinomas and 427 squamous cell carcinomas of the head and neck region were used for this study. Sections were stained immunohistochemically (anti-p16), and PCR analysis (HPV status) was carried out. Correlation of p16 expression/HPV status with features of tumours and with survival of the patients was analysed by means of Chi-squared test and using Kaplan-Meier analysis, respectively. RESULTS: p16 expression was found immunohistochemically in 74% of tumours, but was not significantly correlated with features of the tumours, but recurrence-free survival of the patients (P = 0.009) if located predominantly nuclear. On the other hand neither intensity of p16 expression (P = 0.41) nor HPV status (P = 0.82) had any effect on these two aspects. CONCLUSION: Immunohistochemical expression of p16 alone provides a limited tool for diagnosis and prognosis of carcinomas of the head and neck region. Immunohistochemical analysis of p16 depending on its intracellular location might serve as a surrogate marker for HPV infection.

Odontogenic infections: an 8-year epidemiologic analysis in a dental emergency outpatient care unit.

OBJECTIVES: The purpose of this investigation was to analyze epidemiological patterns, clinical features and the management of odontogenic infections in patients undergoing treatment in a dental emergency outpatient care unit. STUDY DESIGN: A retrospective analysis of 58 161 case records of patients presenting to an emergency outpatient unit in Hamburg, Germany between 2000-2007 was performed. From this pool, patients with odontogenic infections were identified using an ICD-10 code, analyzing age, gender, medical co-morbidities, duration of pain, ratio of infiltrates/abscesses, affected teeth, management of infection and administered antibiotics. RESULTS: Of the 58 161 patients, 5357 (9.2%) were identified as having odontogenic infections, with 2689 (50.2%) inflammatory infiltrates and 2668 (49.8%) abscesses. Mean age was 34.8 ± 16.8 years. As the primary site of odontogenic infection, the most significantly affected teeth were the maxillary and mandibular first molars. Patients in age-group 20-29 years (25.1%) utilized the emergency care unit more frequently than other age groups. Clindamycin was the most frequently administered antibiotic. CONCLUSIONS: Early recognition, diagnosis and management of odontogenic infections are requisite for avoiding or minimizing the development of potential complications. Strategies and evidence-based protocols should be developed within the dental ambulatory care sector, advancing interdisciplinary cooperation between general dentists and oral or maxillofacial surgeons.

Virtual dental surgery as a new educational tool in dental school.

PURPOSE: The virtual environment of the Voxel-Man simulator that was originally designed for virtual surgical procedures of the middle ear has been adapted to intraoral procedures. To assess application of the simulator to dentistry, virtual apicectomies were chosen as the pilot-test model. METHODS: A group of 53 dental students provided their impressions after virtual simulation of apicectomies in the Voxel-Man simulator. RESULTS: Fifty-one of the 53 students recommended the virtual simulation as an additional modality in dental education. The students indicated that the force feedback (e.g. simulation of haptic pressure), spatial 3D perception, and image resolution of the simulator were sufficient for virtual training of dental surgical procedures. CONCLUSION: The feedback from dental students involved in this pilot-test has encouraged our interdisciplinary group to continue further development of the simulator with the goal of creating new training strategies in dental and medical education.

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.

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.

The use of navigation (BrainLAB Vector vision(2)) and intraoperative 3D imaging system (Siemens Arcadis Orbic 3D) in the treatment of gunshot wounds of the maxillofacial region.

PURPOSE: Gunshot wounds are a rare occurrence during times of peace. The removal of projectiles is recommended; in some cases, however, this is a controversy. The reproduction of a projectile image can be difficult if it is not adjacent to an anatomical landmark. Therefore, navigation systems give the surgeon continuous real-time orientation intraoperatively. The aim of this study was to report our experiences for image-guided removal of projectiles and the resulting intra- and postoperative complications. PATIENTS AND METHODS: We investigated 50 patients retrospectively; 32 had image-guided surgical removal of projectiles in the oral and maxillofacial region. Eighteen had surgical removal of projectiles without navigation assistance. RESULTS: There was a significant correlation (p = 0.0136) between the navigated surgery vs. not-navigated surgery and complication rate, including major bleeding (n = 4 vs. n = 1, 8% vs. 2%), soft tissue infections (n = 7 vs. n = 2, 14% vs. 4%), and nerval damage (n = 2 vs. n = 0, 4% vs. 0%; p = 0.038) and between the operating time and postoperative complications. A high tendency between operating time and navigated surgery (p = 0.1103) was shown. When using navigation system, we could reduce operating time. CONCLUSION: In conclusion, there is a significant correlation between reduced intra- and postoperative complications, including wound infections, nerval damage, and major bleeding, and the appropriate use of a navigation system. In all these cases, we could present reduced operating time. Cone-beam computed tomography plays an important role in detecting projectiles or metallic foreign bodies intraoperatively.

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.

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.

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.

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.

Postoperative complications in 202 cases of microvascular head and neck reconstruction.

INTRODUCTION: This retrospective study was intended to determine the incidence and causes of postoperative complications in patients following head and neck reconstruction using microvascular free flaps. PATIENTS AND METHODS: A total of 202 consecutive microvascular free flaps were performed for reconstruction of the head and neck by the same surgeon, 85% of the defects arose following the treatment of malignancies. Flap donor sites included latissimus-dorsi flap (n=83), radial forearm (n=35), fibula (n=31), iliac crest (n=36), TRAM flap (n=3), groin flap (n=l), jejunal flap (n=13). The incidence of postoperative complications and patient-related characteristics (age, sex, diagnosis, comorbidity level, operation duration, defect site, history of radiotherapy/chemotherapy) were retrospectively analyzed. RESULTS: Free flaps proved to be extremely reliable, with a 2.9% incidence of free flap failure. Postoperative medical complications occurred in 11.4% of cases, with cardiac, pulmonary and infectious complications predominating. CONCLUSION: The present study confirms that free flaps are extremely reliable in achieving successful reconstruction of the head and neck. The incidence of postoperative complications is related to the preoperative comorbidity.

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.

Clinical indications and perspectives for intraoperative cone-beam computed tomography in oral and maxillofacial surgery.

OBJECTIVES: Intraoperative cone-beam computerized tomography (CBCT) imaging has been introduced in oral and maxillofacial surgery. Using midfacial fractures as the pioneer model, this study describes the spectrum of further promising clinical indications for intraoperative CBCT and a clinical combination with intraoperative navigation. STUDY DESIGN: One hundred seventy-nine patients admitted for surgical treatment of the facial skeleton were included in the study. Intraoperatively, 3-dimensional images were generated with the mobile CBCT scanner Arcadis Orbic 3D, obtained from Siemens Medical Solutions, in a variety of indications. RESULTS: The acquisition of the data sets was uncomplicated, and image quality was sufficient to assess the postoperative result in all cases. In the example of a facial gunshot injury, a navigation system for intraoperative localization of the metal foreign bodies was used.