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Insula is considered an important region of the brain in the generation and maintenance of a wide range of psychiatric symptoms, possibly due to being key in fundamental functions such as interoception and cognition in general. Investigating the possibility of targeting this area using non-invasive brain stimulation techniques can open new possibilities to probe the normal and abnormal functioning of the brain and potentially new treatment protocols to alleviate symptoms of different psychiatric disorders. In the current study, COMETS2, a MATLAB based toolbox was used to simulate the magnitude of the current density and electric field in the brain caused by different transcranial direct current stimulation (tDCS) protocols to find an optimum montage to target the insula and its 6 subregions for three different current intensities, namely 2, 3, and 4 mA. Frontal and occipital regions were found to be optimal candidate regions.. The results of the current study showed that it is viable to reach the insula and its individual subregions using tDCS., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Transcranial direct current stimulation (tDCS) is a promising tool to enhance therapeutic efforts, for instance, after a stroke. The achieved stimulation effects exhibit high inter-subject variability, primarily driven by perturbations of the induced electric field (EF). Differences are further elevated in the aging brain due to anatomical changes such as atrophy or lesions. Informing tDCS protocols by computer-based, individualized EF simulations is a suggested measure to mitigate this variability., Objective: While brain anatomy in general and specifically atrophy as well as stroke lesions are deemed influential on the EF in simulation studies, the influence of the uncertainty in the change of the electrical properties of the white matter due to white matter lesions (WMLs) has not been quantified yet., Methods: A group simulation study with 88 subjects assigned into four groups of increasing lesion load was conducted. Due to the lack of information about the electrical conductivity of WMLs, an uncertainty analysis was employed to quantify the variability in the simulation when choosing an arbitrary conductivity value for the lesioned tissue., Results: The contribution of WMLs to the EF variance was on average only one tenth to one thousandth of the contribution of the other modeled tissues. While the contribution of the WMLs significantly increased (p≪.01) in subjects exhibiting a high lesion load compared to low lesion load subjects, typically by a factor of 10 and above, the total variance of the EF didnot change with the lesion load., Conclusion: Our results suggest that WMLs do not perturb the EF globally and can thus be omitted when modeling subjects with low to medium lesion load. However, for high lesion load subjects, the omission of WMLs may yield less robust local EF estimations in the vicinity of the lesioned tissue. Our results contribute to the efforts of accurate modeling of tDCS for treatment planning., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: Calcium phosphates are clinically established as bone defect fillers. They have the capability of osseoconduction and are characterized by a slow resorption process. The present study evaluated the suitability of a newly developed calcium phosphate cement modified with collagen type I., Study Design: The modified cement paste was inserted in differently designed defects of 10 minipigs. Further, an alveolar ridge augmentation was performed, applying the cement paste. The cement hardened in situ during the operation, forming a hydroxyapatite collagen composite. Animals were sacrificed after 1, 3, 6, 12, and 18 months. The tissue integration and resorption process was then evaluated using nondecalcified microsections. All animals were evaluated for histology., Results: The implanted material showed osseoconductive characteristics. Resorption started from the edge of the defect zone, and bone substitution followed rapidly. Twelve months after placement of the cement, complete remodeling was observed., Conclusion: It can be concluded that the applied hydroxyapatite-collagen cement composite shows good resorption and bone integration.

Aim: The purpose of this study was to compute the load on different osteosynthesis plates in a simplified model using finite element analysis, and to find out whether miniplates were sufficiently stable for application at the mandibular angle., Patients: Data from 277 patients with 293 fractures of the mandibular angle have been evaluated., Methods: A computation model using finite elements was established in order to compute mechanical stress occurring in osteosynthesis plates used for fixation of fractures of the mandibular angle. In the second part of this study, the data from all in-patients treated for fracture of the mandibular angle were evaluated retrospectively. Age and sex of the patients, cause of fracture, state of dentition, type of therapy as well as complications were noted., Results: In those tests, both the 1.0 mm miniplate and the 2.3 mm module plate were sufficiently stable. The rate of major complications (requiring revisional surgery with general anaesthesia) amounted to approximately 17% in comminuted fractures, or in non-compliant patients in which primary stability with a single miniplate did not appear sufficient, so that other osteosynthesis methods were used in addition. This rate was considerably higher than that in simple mandibular fractures. Simple fractures of the mandibular angle were just treated with one miniplate following Champy's guidelines strictly. In these fractures the rate of major complications was only 2.3%., Conclusion: In comminuted fractures and in non-compliant patients, the use of a stronger osteosynthesis material should be considered while in all other cases application of a single 1.0 mm miniplate was regarded as sufficient for fixation using open reduction.

It was the purpose of this study to evaluate the outcome of lag screw osteosynthesis in severely displaced fractures or fracture dislocations of the mandibular condyle as well as intra- and postoperative complications of this technique. From 1980 to 1996 a total of 492 patients with condylar fractures were treated with lag screw osteosynthesis. Clinical and radiological follow-ups were carried out in 230 patients with severely displaced fractures or fracture dislocations of the mandibular condyle. The period between surgery and follow-up was between 6 months and 2 years. The majority of the clinical results were satisfactory presumably due to the anatomically exact reduction of the fragment (93.4%). Extreme anatomic variations of the mandible (5.8%) and incorrect application of the technique (8.8%) resulted in reduced functional stability of lag screw osteosynthesis. Insufficient fragment reduction and postoperative complications (such as wound infection) entailed restriction of mandibular mobility and arthrotic deformations were seen as persistent radiological irregularities of the mandible. It has been possible to avoid complications and to achieve favourable functional results in complicated fractures of the mandibular condyle by applying strict indications for lag screw osteosynthesis and by considering the individual anatomical peculiarities.