Characterisation of apical bone lesions: Comparison of MRI and CBCT with histological findings - a case series.

PURPOSE: The aim of this case series was to compare magnetic resonance imaging (MRI) with cone beam computed tomography (CBCT) in the representation of periapical osteolyses. Based on the histological findings, the potential of MRI for further lesion characterisation was investigated. MATERIALS AND METHODS: Thirteen patients (average age: 41 ±â€…27 years) with a total of 15 periapical lesions (five molars, five premolars, and five front teeth) were examined. Lesion characterisation was based on the homogeneity/heterogeneity of the lesions, the signal intensity within the lesion compared to the surrounding tissue and differences in the signal intensities between different MRI contrast weightings. Results were compared with CBCT and histological findings. RESULTS: Although all patients presented with dental restorations, such as fixed partial dentures and filling materials, all periapical lesions could be diagnosed with either imaging modality. Histologically, 13 cysts and two apical granuloma were confirmed. In CBCT, the similar appearance of all lesions did not allow any further characterisation. In MRI, radicular cysts and granuloma could be characterised by their appearance in the MRI images with different contrast weightings. The MRI-derived characterisations were consistent with the histological findings. CONCLUSIONS: The presented study shows that the application of multi-contrast MRI may lead to better characterisation of apical lesions, thus enabling an improved patient-specific selection of the optimal treatment option. Conflict-of-interest statement: MAG, ESS, and LKS do not report any potential conflict-of-interest; EH and JU are employees of Sirona Dental Systems; VR is receiving a research grant by Sirona Dental Systems.

External pin fixation for stabilization of the mandible--comeback of a method: historical review and first experiences with the 'mandible external fixator'.

BACKGROUND: The market-release of a modified 'mandible external fixator' appliance prompted us to reconsider the issues of pin fixation. MATERIALS AND METHODS: The first product line of the 'mandible external fixator set-Phase1' (Synthes Maxillofacial, Paoli, USA) contains the three classical basic components: percutaneous pins, clamps, and pre-bent connecting rods. The innovative features are a lightweight titanium construct and the snap-on design of the clamps. The framework is assembled by a single connecting bar (monofixator) in the so-called visor-style technique. INDICATIONS: The indication was restricted to: (1) pathological fractures, e.g., in infected osteoradionecrosis; (2) resectional defects; and (3) emergency care of mandible fractures in a multi-piece, heavy comminution, or defect pattern. PATIENTS: The mandible external fixator was used in a series of ten patients (all male, 39-73 years), for head and neck tumor sequelae in eight cases (n = 5-curatively, n = 3-palliation) and in two polytrauma cases. RESULTS: All patients had benefited from the functional restitution of the mandibular continuity avoiding major surgical exposure and additional soft tissue damage. The application using a 'visor-style technique' was appropriate for bridging defects or single comminution zones (n = 9). In the emergency care of a polytraumatized patient with multifragmentation all over the mandible divisions, it did not contribute to an adequate realignment. In curative tumor treatment (patients n = 5), a conversion either to internal fixation (n = 2) or revascularized bone grafting (n = 3) ensued after prolonged intervals of 40-170 days. Pin track infections or loosening did not occur. CONCLUSION: The hallmark of external pin fixation is its atraumatic soft tissue management. Hence, it offers peculiar options in singular comminution or defect areas associated with bone pathology and/or soft tissue alterations.

Mycophenolic acid therapy after cyclophosphamide pulses in progressive IgA nephropathy.

BACKGROUND: In progressive IgA nephropathy (IgAN), cyclophosphamide or steroids have been used to reduce the loss of renal function, but disease progression may occur after the end of treatment. The value of mycophenolic acid (MPA) maintenance therapy following initial immunosuppression in progressive IgAN is largely unknown. METHODS: In a prospective single-center trial, 20 patients with advanced IgAN (median glomerular filtration rate [GFR], 22 ml/min) and disease progression after cyclophosphamide pulse (CyP; n=18) or steroid pulse therapy (n=2) were treated with MPA for a median of 27 months. MPA dosages (initially mycophenolate mofetil 500 mg twice daily) were adjusted according to predose plasma concentrations (target concentrations 1.5 to 4 microg/mL). The course of renal function was assessed by linear regression of glomerular filtration rates. RESULTS: Median loss of renal function per month was significantly reduced from -0.8 ml/min to -0.03 ml/min per month after 6 months, to -0.05 ml/min per month after 12 months, and to -0.12 ml/min per month at the end of the study after median 27 months (p<0.05). An improved or stable GFR was observed in 16 of 20 patients during the first 12 months, and sustained in 10 patients during 24 months of follow-up. Proteinuria decreased significantly from 1.1 g/L to 0.4 g/L during MPA treatment (p=0.018). CONCLUSION: Our results indicate that MPA may be beneficial to slow down the loss of renal function in patients with progressive IgAN after previous immunosuppressive treatment.