The effectiveness of decompression as initial treatment for jaw cysts: A 10-year retrospective study.

BACKGROUND: Decompression is an approved alternative to cystectomy in the treatment of jaw cysts. This study aimed to evaluate its effectiveness as an initial procedure, as well as factors with potential to influence outcome. MATERIAL AND METHODS: the frequency of decompression was analysed, whether completed in one session or followed by enucleation at the Division of Oral Surgery and Orthodontics, Department of Dental Medicine and Oral Health, Medical University of Graz, from 2005 to 2015. Further analysis focussed on factors potentially influencing outcome: cyst location, histopathology, means of preserving the cyst opening, cyst size, patient age. RESULTS: In all, 53 patients with 55 jaw cysts (mean age of 35.1) were treated by initial decompression in the ten-year period. In the majority of cases, histopathological analysis revealed a follicular cyst (43.6%), followed by odontogenic keratocysts (23.7%), radicular cysts (21.8%), residual cysts (7.3%) and nasopalatine cysts (3.6%) Treatment was completed with a single decompression in 45.5% of the cases. Among those, 72.0% were follicular cysts and 8.0% odontogenic keratocysts. Subsequent enucleation was needed in 54.5% of all cases, with a majority in the keratocystic group (36.7%). Histological findings, means of keeping the cyst open, and patient age were found to influence the effectiveness of decompression. CONCLUSIONS: Decompression could be performed as a procedure completed in one session or combined with subsequent enucleation, mainly dependent on histopathological findings. Subsequent enucleation of odontogenic keratocysts is highly recommended.

Deviations of different systems for guided implant surgery.

OBJECTIVES: To compare the deviation of different systems for Guided Implant Surgery (GIS) related to the specific tolerance between drills and sleeves. MATERIAL AND METHODS: Four different systems for GIS and their appropriate sleeves were used: Camlog Guide (CG), Straumann Guided Surgery (SG), SIC Guide (SIG), and NobelGuide (NG). System-appropriate metal sleeves were inserted into plexiglass boxes, and guided drilling procedure was performed (i) holding the drills in the most centric position of the sleeves and (ii) applying forces eccentrically. Digital microscope images of the plexiglass boxes were taken and axial deviations were calculated based on the Pythagorean Theorem, whereas coronal and apical deviations were measured with a corresponding software-device and calculated by subtracting the measured deviations from the original diameter of the drills. Statistically significant differences between centric and eccentric drilling were determined applying the t-test for independent data. RESULTS: The axial deviation ranged from 0° (SG) to 5.64° (CG). The apical deviations varied between 0.01 mm (SIG) and 3.2 mm (NG) and the coronal deviations ranged from 0.01 mm (SIG) to 1.60 mm (NG). In terms of angular deviation, there were statistically significant differences between centric and eccentric drilling for all four systems. Coronal and apical deviations, showed no statistical significance between centric and eccentric drilling for SIG and NG, in contrast to CG and SG. CONCLUSIONS: The clinician may have considerable impact on the accuracy of GIS when applying eccentric forces.

Transcrestal maxillary sinus augmentation: Summers' versus a piezoelectric technique--an experimental cadaver study.

OBJECTIVES: Sinus floor augmentation using transalveolar techniques is a successful and predictable procedure. The aim of the study was to compare the performance of conventional hand instruments using mallets and osteotomes with that of piezoelectric-hydrodynamic devices for maxillary sinus floor elevation. MATERIAL AND METHODS: In 17 undamaged cadaver heads on randomly allocated sites, Schneiderian membrane elevation was carried out transcrestally using piezosurgery and a hydrodynamic device or by conventional hand instrumentation. After simulation of sinus augmentation by the use of a radiopaque impression material, a post-operative CT scan was carried out and volumes were determined. Statistic significant differences between the two methods were evaluated by nonparametric Mann-Whitney U-test with P < 0.05. RESULTS: A mean graft volume of 0.29 ± 0.18 cm(3) (0.07-0.60 cm(3)) was measured for the Summers' technique compared to 0.39 ± 0.32 cm(3) (0.05-1.04 cm(3)) for the Sinus Physiolift(®) technique. There is no statistically significant difference with regard to trauma to the Schneiderian membrane or augmented volume. CONCLUSIONS: Both techniques generate expedient augmentation volume in the posterior atrophic maxilla. The piezoelectric technique can be recommended as an alternative tool to graft the floor of human maxillary sinuses.

Clinically relevant complications related to posterior atlanto-axial fixation in atlanto-axial instability and their management.

BACKGROUND: The Magerl transarticular technique and the Harms-Goel C1 lateral mass-C2 isthmic screw technique are the two most commonly used surgical procedures to achieve fusion at C1-C2 level for atlanto-axial instability. Despite recent technological advances with an increased safety, several complications may still occur, including vascular lesions, neurological injuries, pain at the harvested bone graft site, infections, and metallic device failure. METHODS: We retrospectively analyzed all patients (n=42 cases) undergoing a Harms-Goel C1-C2 fixation surgery with polyaxial C1 lateral mass screws and C2 isthmic screws at two different institutions between 2003 and 2012 and report clinical and radiological complications. One patient was lost to follow-up. The mean follow-up of the remaining 41 patients was 18.7 months (range 12-90). A clinically relevant complication was defined as a complication determining the onset of a new neurological deficit or requiring the need for a revision surgery. RESULTS: A total of 14 complications occurred in 10 patients (24.4% of 41 patients). Greater occipital nerve neuralgia was evident in 4 patients (9.8%). All but one completely resolved at the end of the follow-up. Persistent neck pain was reported by 3 patients (7.3%), hypoesthesia by 1 patient (2.4%), and anesthesia in the C2 area on both sides in 1 patient (2.4%). Furthermore, a superficial, a deep, and a combined superficial and deep wound infection occurred in 1 patient each (2.4%). One patient (2.4%) had pain at the iliac bone graft donor site for several weeks with spontaneous resolution. A posterior progressive intestinal herniation through the iliac scar was seen in 1 case (2.4%), which required surgical repair. No vascular damages occurred. Altogether, 5/41 patients (12.2%) had a clinically relevant complication including 4 patients necessitating a revision surgery at the C1-C2 level (9.8%). CONCLUSIONS: Atlanto-axial fixation surgery remains a challenging procedure because of the proximity of important neurovascular structures. Nevertheless, on the basis of our current experience, the C1 lateral mass-C2 isthmic screw technique appears to be safe with a low incidence of clinically relevant complications. Postoperative C2 neuralgia, as the most frequent problem, is due to surgical manipulation during preparation of the C1 screw entry point.

Bone tissue response to an oily calcium hydroxide suspension in tibial defects. An experimental pilot study in minipigs.

OBJECTIVES: The present study was conducted to evaluate the bone tissue response after the application of an oily calcium hydroxide suspension (OCHS) into defects created in the tibial bone of minipigs. MATERIALS AND METHODS: Standardized defects (2 ccm) were created into the tibia of 4 Goettinger minipigs. Defects in the test group (n = 4) were filled with OCHS (Osteora, DFS-Diamon, Riedenburg, Germany). Defects in the control group (n = 4) were filled with venous blood. Animals were sacrificed after healing periods of 4 and 8 weeks. Tibias were dissected, soft tissues removed and processed for histological analysis. Digital images (×200) were evaluated using the software CellD (Soft Imaging System, Münster, Germany). The following histomorphometrical landmarks were identified: defect size, mineralized tissue, non-mineralized tissue and residual OCHS. RESULTS: Healing was uneventful in all four animals. In the test group, new bone formation was observed in the vicinity of the defect margins whereas the centre of the defect was dominated by non-mineralized tissue. Mean percentages of mineralized tissue after 4 weeks were 23.01% in the test group vs. 43.45% in the control group. The mean value for residual OCHS was 7,11% at 4 weeks. After 8 weeks mean percentages of mineralized tissue were 28.15% in the test group vs. 44.39% in the control group as well as 7.05% for residual OCHS. CONCLUSION: Within the limits of the present pilot study it can be concluded that OCHS did not have a beneficial effect on new bone formation. To prove an osteoinductive potential of OCHS further studies based on a higher number of samples are needed.

Acute traumatic central cord syndrome: a comprehensive review.

Acute traumatic central cord syndrome (ATCCS) is the most common type of incomplete spinal cord injury, characterized by predominant upper extremity weakness, and less severe sensory and bladder dysfunction. ATCCS is thought to result from post-traumatic centro-medullary hemorrhage and edema, or, as more recently proposed, from a Wallerian degeneration, as a consequence of spinal cord pinching in a narrowed canal. Magnetic Resonance Imaging is the method of choice for diagnosis, showing a typical intramedullary hypersignal on T2 sequences. Non-surgical treatment relies on external cervical immobilization, maintenance of a sufficient systolic blood pressure, and early rehabilitation, and should be reserved for patients suffering from mild ATCCS. Surgical management of ATCCS consists of posterior, anterior or combined approaches, in order to achieve spinal cord decompression, with or without stabilization. The benefits of early surgical decompression in the setting of ATCCS remain controversial due to the lack of clinical randomized trials; recent studies suggest that early surgery (less than 72hours after trauma) appears to be safe and effective, especially for patients with evidence of focal anatomical cord compression.

The influence of bone marrow aspirates and concentrates on the early volume stability of maxillary sinus grafts with deproteinized bovine bone mineral - first results of a RCT.

OBJECTIVES: The aim of the study was to investigate whether bone marrow aspirates (BMA) and concentrates (BMAC) influence the grafts' stability when added to deproteinized bovine bone mineral (DBBM) within the first 6 months after maxillary sinus augmentation. MATERIAL AND METHODS: 26 CT data of 13 patients undergoing bilateral maxillary sinus augmentation in a split-mouth design were evaluated using the Voxim software by comparing the graft volumes 2 weeks after the sinus lift procedure with CT data obtained 6 months later. DBBM with (N = 6) or without tibial BMA (N = 6) and DBBM with (N = 7) and without adding iliac BMAC (N = 7) were used as grafts. Absolute and percentage changes in the graft volumes were evaluated, and the nonparametric Mann-Whitney U-test and the nonparametric Wilcoxon test were performed to determine significant differences between the graft volumes within each single split-mouth group and between the two groups. RESULTS: Overall, the volumes decreased between 15% and 21%. All single groups showed statistically significant decreases over 6 months of healing. The time-dependent changes in volumes between the different groups were not statistically significant (P = 0.818). CONCLUSIONS: An evident decrease in graft volume over the first 6 months of healing has to be expected irrespectively of graft composite. Neither BMA nor BMAC seem to have an evident impact. Overaugmentation seems recommendable in two-stage maxillary sinus surgery.

Spinal extradural arachnoid cyst: review of surgical techniques.

Extradural arachnoid cysts of the spine are a rare cause of spinal cord and nerve root compression, usually in the mid to lower thoracic spine and at the thoraco-lumbar junction in a posterior position. Local pain and myelopathy occur predominantly in young adults, and MRI reveals a well-demarcated extradural lesion, iso-intense to cerebrospinal fluid. We report a 33-year-old woman with an extradural arachnoid cyst from T11 to L1 and review the surgical techniques reported in the literature.

Rapid maxillary expansion screws on the test bench--a pilot study.

In order to apply high, short-term forces during rapid maxillary expansion (RME) to the sutures of the maxilla with minimum loss of force and without causing unwanted side-effects (dentoalveolar tipping, etc.), the appliance should be as rigid as possible. The retention arms of the RME screws, representing a particularly vulnerable and stressed weak point of RME appliances, were the focus of this laboratory technical study. Retention arms of 16 types of RME screws comprising four arms and one with eight arms were examined using a three-point bending test. According to their ability to absorb the applied bending loads, the screws were classified in product groups from 1 (highest) to 6 (lowest). Fifteen of the tested retention arms (stainless steel), despite having the same diameter (1.48-1.49 mm), differed up to 69.81 per cent between the highest (288.0 N) and lowest (169.6 N) maximum force parameters and up to 66.40 per cent between the highest (3325.9 N/mm(2)) and lowest (1998.7 N/mm(2)) maximum bending stress parameters. Due to optimum formability, though reduced rigidity, a titanium screw for nickel-sensitive patients (group 6) displayed the lowest force and bending tension values. The stainless steel double arms of the eight-arm screw device welded on both ends displayed the highest force data. The mean ductilities of the groups with the most and least rigid single steel arms differed by 22.77 per cent. Statistical analysis using the Pearson correlation coefficient revealed a significant indirect correlation between ductility and both maximum force (r = -0.780, P < 0.001) and maximum bending stress (r = -0.778, P < 0.001). The SUPERscrews, the Tiger Dental four-arm screw (group 1), and the eight-arm screw displayed the highest capacity to absorb an applied bending load. The screws in groups 3-6 appear acceptable for RME during the pre-pubertal period, whereas in the pubertal and post-pubertal period, groups 1 and 2 are sufficient. In early adulthood only the screws in group 1 and especially the eight-arm screw seem advisable, as mechanical demands increase with age.

Reproducibility of volumetric measurements on maxillary sinuses.

Although computer assisted volumetric quantification of human maxillary sinuses is commonly used to measure volumetric changes during life, reliability data for this procedure are lacking. The objective of this retrospective study is to test a semi-automatic virtual volumetric analysis technique on 36 CT scans of human maxillary sinuses. Three examiners with different clinical experience performed all measurements in three replicates. As principle of proof, the technique was examined on 12 phantoms with known volumes. The validation of the method revealed that the mean relative error was 0.364%. For the retrospective volumetric measurements from maxillary sinuses the intra- and inter-examiner agreement was quantified using appropriate intraclass correlation coefficients (ICC 1,k and ICC 2,k) and the Bland-Altman analysis. ICC values ranging from 0.997 to 0.999 indicate almost perfect agreement for intra- and inter-examiner data. The Bland-Altman analysis demonstrated good intra- as well as inter-examiner agreement for the two proficient examiners and a lack of agreement for the untrained examiner. It can be concluded that this measurement procedure using CT scans could be strongly recommended for clinical application to determine the volume of human maxillary sinuses reliably.

All-ceramic immediate restoration of one-piece zirconium dioxide implants.

The multipiece nature of different implant systems is problematic for a number of reasons. The greatest challenge is bacterial colonization of the implant and of the surrounding tissue, because of the implant/abutment and abutment/crown interfaces, as well as the micromovements of the individual components of the implant. A possibility of eliminating microgaps between the individual components of the implant on the one hand and avoiding micromovements on the other is described in this paper.

The supernumerary nasal tooth.

Teeth exceeding the normal dental complement that have erupted into the nasal cavity are a rare pathological entity. This case report describes a female patient with recurrent complaints and fetid discharge from the left nasal cavity. The suspected clinical diagnosis of a supernumerary nasal tooth was confirmed by computed tomography. After endoscopic removal, the tooth was examined using X-ray microtomography and thin-section preparations; these findings are presented for the first time. A literature search identified 25 supernumerary nasal teeth in 23 patients.

Posterior atlanto-axial fixation with polyaxial C1 lateral mass screws and C2 pars screws.

PURPOSE: C1-C2 instability or painful osteoarthritis are recognised indications for posterior atlanto-axial fixation. In the traditional trans-articular C1-C2 screw fixation, up to 20% of patients cannot have safe placement of bilateral screws in the event of a medially located vertebral artery and a straight screw trajectory in the sagittal plane. The more recently developed C1-C2 fixation technique with individual C1 lateral mass screws and converging C2 pars screws can be employed in case of a medially located vertebral artery and has comparable biomechanical strength. This is a prospective observational study to investigate the advantages, the safety, and the drawbacks of posterior atlanto-axial fixation with polyaxial C1 lateral mass screws and C2 pars screws. METHODS: Twelve consecutive patients with C1-2 instability (n = 11) and painful osteoarthritis (n = 1) underwent a posterior atlanto-axial fixation with polyaxial C1 lateral mass screws and C2 pars screws. The average follow-up was 16 months and all patients reached the 12-month follow-up. FINDINGS: No hardware failure occurred in any of the patients. Correct screw placement and construct stability was found in all 12 patients (100%) at 6 and 12 months after surgery. Mean neck pain on a visual analogue scale (VAS) was 2.1 at 6 months and 2.0 at 12 months. Only transient complications were observed: one patient presented with progressive intestinal herniation through the iliac crest scar; one suffered from severe pain at the posterior iliac crest for 3 months and three patients complained of annoying pain/dysaesthesia in the C2 dermatome for 3-6 months after surgery. CONCLUSION: This study confirms that posterior atlanto-axial fixation with polyaxial C1 lateral mass screws and C2 pars screws is a safe and effective surgical option in the treatment of atlanto-axial instability or painful osteoarthritis.

Elevated levels of tumor necrosis factor-alpha in periradicular fat tissue in patients with radiculopathy from herniated disc.

STUDY DESIGN: Case-control study. OBJECTIVE: To determine whether inflammatory cytokines [tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6 and IL-8] are elevated in tissues intimately surrounding involved nerve roots of patients suffering from radiculopathy form herniated disc (HD). SUMMARY OF BACKGROUND DATA: Proinflammatory cytokines are postulated to play an important role in radiculopathy from HD. Although TNF-alpha has been found in human HD, it is not known whether TNF-alpha concentrations are increased in symptomatic patients. Epidural fat (EF) is another tissue in close contact with nerve roots. Histologic modifications of EF have been reported in patients with sciatica but concentrations of inflammatory cytokines have never been studied. METHODS: Twenty-three lumbar HD along with adjacent EF (EFHD) were harvested from patients with radicular syndrome. As controls, 14 intervertebral discs (IVDs) and 10 samples of EF (EFC) were obtained from patients without radicular syndrome undergoing spine surgery. Tissue explants were incubated ex vivo for 48 hours and the concentrations of cytokines were measured by elisa in the supernatants. Results were standardized according to tissue weight. RESULTS: All 4 cytokines were found at higher concentrations in EFHD compared with HD (P < 0.001). TNF-alpha was the only cytokine found in significantly higher levels in EFHD compared with EFC [median, interquartile range 6.6, (1.6-16.3) pg/mL per milligram of tissue vs. 2.3 (1.3-5.0), P < 0.05] and to subcutaneous fat [0.35 (0-2.28), P < 0.001]. No significant increase of either cytokines was found in HD compared with IVD. CONCLUSION: Higher concentrations of TNF-alpha were found in EF from patients with radiculopathy from HD compared with patients suffering from other type of back pain. These results support the role of TNF-alpha in the pathogenesis of radiculopathy from HD.

Evacuation of a 14-vertebral-level cervico-thoracic epidural abscess and review of surgical options for extensive spinal epidural abscesses.

Spinal epidural abscess (SEA) is a rare infection of the spinal peridural space, usually from haematogenous spread of bacteria from a distant source of infection or from direct extension of an osteomyelitis or paravertebral abscess into the spinal canal. An extensive SEA with involvement of five or more levels is even more exceptional and is a very threatening condition. Different surgical strategies have been used in the typically posteriorly located extensive SEA: multi-level laminectomies at all involved levels; catheter procedures, in which suction (irrigation) catheters are pushed cranially and caudally through selected end-level and intermediate-level fenestrations or laminectomies; or multi-level interlaminar fenestrations at the involved levels. We report the evacuation of a 14-vertebral-level cervico-thoracic SEA by multi-level unilateral fenestrations with 'over-the-top' removal of contralateral abscess formations at all involved levels. We also discuss the surgical strategies for extensive SEA.

Intradural pleural malignant mesothelioma.

Pleural malignant mesothelioma is a rare tumour of the pleural epithelium, which progresses by infiltration into the lung parenchyma, the chest wall, and the mediastinum. Haematogenous spreading may occur in the late stages of the disease. Spinal involvement is exceptional and usually occurs in the vertebral body or epidural space, and intradural location of a mesothelioma is even more uncommon. In this article, a MEDLINE literature review on intradural mesothelioma was conducted and four intradural mesothelioma cases in the English literature were retrieved: one in the intradural extramedullary location and three with intramedullary growth. Additionally, we report a 50-year-old patient with a pleural malignant mesothelioma that spreads across the dura into the spinal cord at T5.

Delayed surgical management of a traumatic bilateral cervical facet dislocation by an anterior-posterior-anterior approach.

Delayed diagnosis (more than one month after injury) of a bilateral cervical facet dislocation is exceptional, and delayed treatment is different from treatment in the acute stage. We describe a neurologically intact 51-year-old patient, in whom the diagnosis of bilateral cervical facet dislocation at C5/6 was made 10 weeks after the trauma. An anterior-posterior-anterior approach was performed, with repositioning during the posterior approach, and with anterior and posterior C5/6 fixation. The patient remained neurologically intact, and radiographic fusion was observed 3, 6, and 12 months postoperatively. Additionally, the (English) literature is reviewed and discussed.

Implantation of a distractible titanium cage after cervical corpectomy: technical experience in 20 consecutive cases.

BACKGROUND: This prospective observational study was undertaken to investigate the advantages, the safety, and the drawbacks of reconstructing a cervical corpectomy with a distractible corpectomy cage. According to the author's literature search, this is the second clinical report on a distractible cervical corpectomy cage. METHOD: 20 Consecutive patients underwent a single- or multi-level cervical corpectomy for spondylotic myelopathy, traumatic fracture, or tumor. The corpectomy defect was reconstructed by means of a distractible titanium cage, and local bone from the corpectomy was layed around the cage for fusion. An anterior cervical plate and/or a posterior lateral mass or pedicle screw fixation was added in all patients. The average follow-up was 14 months, and all patients had at least 12 months of follow-up. FINDINGS: No hardware failure occurred in any of the patients. Construct stability was achieved in 19 out of 20 patients (95%) at 12 months postoperatively. The mean regional lordosis was 1 degrees preoperatively, 9 degrees postoperatively, and 7 degrees at the follow-up. Mean neck pain on a VAS was 3.9 preoperatively, and 2.6 at 12 months. There were three perioperative complications: transient neurological worsening in one patient, one transient vocal cord paralysis, and persistent dysphagia in one patient. CONCLUSION: A single- or multi-level cervical corpectomy can be safely and effectively reconstructed by a distractible titanium cage and local bone graft in combination with anterior cervical plating and/or posterior lateral mass/pedicle screw fixation. Potential advantages of this technique are an unforced cage insertion in its non-distracted position, press-fitting the cage into the corpectomy defect through cage distraction, correction of kyphosis or preservation of local lordosis through cage distraction, and the absence of donor site morbidity. However, the stability rate in the current series did not exceed the fusion rates of auto- or allografts.

Resection of thoracic dumbbell neurinomas: single postero-lateral approach or combined posterior and transthoracic approach?

Dumbbell tumours are those with an intraspinal and a paraspinal component, connected through a frequently enlarged and eroded intervertebral foramen. Most dumbbell tumours are located in the thoracic spine, and most of them are schwannomas. The extraspinal tumour extension is usually larger than the intraspinal tumour part, but the intraspinal tumour component commonly causes the typical symptoms: local pain and symptoms from spinal cord compression in the thoracic spine. Diagnosis is best established by magnetic resonance imaging with and without contrast agent injection. Controversy exists as to whether to remove thoracic dumbbell tumours using a single posterior approach with posterolateral extension or using a combined posterior and transthoracic approach. We report the removal of a dumbbell neurinoma at T6/7 using a single posterior midline approach with laminectomy and costo-transversectomy and review the literature regarding the approaches to thoracic dumbbell tumours.

Surgical management of cervical fractures in ankylosing spondylitis using a combined posterior-anterior approach.

The management of cervical fractures in ankylosing spondylitis patients is controversial. In the present article, a literature review is conducted, and the author's experience with four consecutive cases, operated on using a combined approach, is reported. One patient was operated on using the combined approach after developing progressive deformity in a halo fixator, one patient after early redislocation of an anterior monosegmental fixation, and two patients were operated on primarily using the combined approach. All four patients achieved good alignment and immediate stability and no dislocation or deformity was observed during the mean observation period of 11 months.