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.

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.

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.

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.

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.

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.

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.

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.

Unstable upper and middle thoracic fractures. Preliminary experience with a posterior transpedicular correction-fixation technique.

A number of conservative and operative approaches have been described for the treatment of unstable traumatic upper and middle thoracic fractures. The advantage of surgical correction and fixation/fusion lies in its potential to restore sagittal and coronal alignment, thereby indirectly decompressing the spinal cord. A consecutive series of 8 patients with unstable traumatic upper and middle thoracic fractures is reviewed. In all patients, polyaxial pedicle screws were inserted bilaterally into the two levels above and below the fracture. Rods that were less contoured ("undercontoured") than the regional hyperkyphosis at the injured level, were anchored to the caudal four screws. The cranial four screws, with the vertebrae to which they were inserted, were then progressively pulled posteriorly onto the undercontoured rods with rod reducers, thus correcting the hyperkyphosis and anterolisthesis. The mean follow-up was 15 months. The mean regional kyphosis was 23 degrees preoperatively, 17 degrees postoperatively and 18 degrees at follow-up. The mean anterolisthesis was 8 mm preoperatively, 1 mm postoperatively and 1 mm at follow-up. No hardware failure occurred. Five patients with complete spinal cord injury at presentation made no neurological recovery, two patients with incomplete spinal cord injury initially (ASIA B), recovered substantially (to ASIA D), and the patients who were neurologically intact at presentation remained so.

Traumatic vertical atlantoaxial dislocation.

We present a case of traumatic vertical atlantoaxial dislocation of 16 millimetres with a fatal outcome. We hypothesize that this extremely rare traumatic vertical atlantoaxial dislocation results from insufficiency of the C1/C2 facet capsules after rupture of the tectorial membrane and the alar ligaments.

Intraoperative color-coded duplex sonography for localization of a distal middle cerebral artery aneurysm: technical case report.

OBJECTIVE AND IMPORTANCE: We describe the surgical treatment of a small, distal, middle cerebral artery (MCA) aneurysm, performed using intraoperative color-coded duplex sonography for localization. CLINICAL PRESENTATION: A 55-year-old man presented with a sudden intense headache. Computed tomographic scans revealed a subarachnoid hemorrhage. Angiography demonstrated two MCA aneurysms, one arising from the proximal bifurcation of the right MCA and the other from its distal bifurcation. TECHNIQUE: On Day 1, the proximal MCA aneurysm was clipped via the standard transsylvian approach. The distal MCA aneurysm was identified with the aid of color-coded duplex sonography and was successfully clipped with minimal additional dissection of the sylvian fissure. CONCLUSION: Color-coded duplex sonography provides a two-dimensional image of the brain parenchyma and color-coded flow imaging of cerebral vessels in real time. It may be used for rapid intraoperative localization of small, distally located, cerebral aneurysms.

Thoracic myelopathy due to enlarged ossified yellow ligaments. Case report and review of the literature.

Enlarged ossified yellow ligaments are a rare and poorly understood cause of thoracic myelopathy. The authors report the case of a patient in whom thoracic myelopathy was caused by enlarged ossified yellow ligaments.

Malignant transformation of a spinal cord ganglioglioma--case report and review of the literature.

Gangliogliomas are tumors of mixed glial and neuronal phenotype that usually have a benign clinical course. Rare cases display anaplastic features at the time of first presentation or progress to anaplastic gliomas over extended times. We report on a ganglioglioma of the spinal cord that recurred as a malignant glioma one and a half years after resection. The initial neoplasm was composed of a mixture of well-differentiated ganglionic and astrocytic cells. The recurrent tumor was an anaplastic small-cell glioma. The sole unusual aspect in the initial neoplasm was an abundance of small vessels with calcified walls, which mimicked a vascular malformation.

Bilateral occipital condylar fracture. Case report about successful treatment with SOMI brace.

Treatment guidelines for occipital condyle fractures (OCFs) are not established. Options for unilateral OCF have been discussed in the literature, but not for bilateral cases. We describe a bilateral OCF type II (according to the Anderson/Montesano classification) in a 30-year-old patient, where immobilisation in a SOMI brace (sternal occipital mandibular immobilisation) was successfully used.

Surgical treatment of cervical myelopathy of unclear aetiology.

In some cases neither the clinical pattern nor the findings of magnetic resonance imaging (MRI) can help to determine the cause of a cervical myelopathy. The differential diagnosis of such cases as a rule includes spondylotic myelopathy, a solitary focus of multiple sclerosis and an intramedullary tumour in early stage. Worsening of signs and symptoms due to the circumscribed lesion of the spinal cord can require surgical treatment, even if no certain diagnosis could be stated thus far. The question is how to choose a surgical procedure which is beneficial for all three kinds of spinal cord pathology in their initial stage, which at the same time does not jeopardise spine and spinal cord and allows secondary surgery if needed after the precise nature of the lesion has been assessed. Ventral decompression and fusion with or without dorsal decompression seems to be a convincing procedure.

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.