Publications by authors named "Knipfer Christian"

Objectives: Confocal laser endomicroscopy (CLE) is an optical method that enables microscopic visualization of oral mucosa. Previous studies have shown that it is possible to differentiate between physiological and malignant oral mucosa. However, differences in mucosal architecture were not taken into account.

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In Neurofibromatosis type 1 (NF1), peripheral nerve sheaths tumors are common, with cutaneous neurofibromas resulting in significant aesthetic, painful and functional problems requiring surgical removal. To date, determination of adequate surgical resection margins-complete tumor removal while attempting to preserve viable tissue-remains largely subjective. Thus, residual tumor extension beyond surgical margins or recurrence of the disease may frequently be observed.

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Biomaterials and coating techniques unlock major benefits for advanced medical therapies. Here, we explored layer-by-layer (LbL) deposition of silk fibroin (SF) by dip coating to deploy homogeneous films on different materials (titanium, magnesium, and polymers) frequently used for orthopedic and other bone-related implants. Titanium and magnesium specimens underwent preceding plasma electrolytic oxidation (PEO) to increase hydrophilicity.

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Purpose: Post-interventional hemorrhage can result in serious complications, especially in patients with hemostatic disorders. Identification of safe and efficient local hemostatic agents is important, particularly in the context of an ageing society and the emergence of new oral anticoagulants. The aim of this in vitro study was to investigate the potential of silk fibroin membranes coated with the inorganic polymer polyphosphate (polyP) as a novel hemostatic device in oral surgery.

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Objective: Application of an optical method for the identification of antiresorptive drug-related osteonecrosis of the jaw (ARONJ).

Methods: We introduce shifted-excitation Raman difference spectroscopy followed by U-Net deep neural network refinement to determine bone tissue viability. The obtained results are validated through established histological methods.

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Purpose: Placement of dental implants has evolved to be an advantageous treatment option for rehabilitation of the fully or partially edentulous mandible. In case of extensive horizontal bone resorption, the bone volume needs to be augmented prior to or during implant placement in order to obtain dental rehabilitation and maximize implant survival and success.

Methods: Our aim was to systematically review the available data on lateral augmentation techniques in the horizontally compromised mandible considering all grafting protocols using xenogeneic, synthetic, or allogeneic material.

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Background: Human infection with the SARS-CoV-2 virus has caused a pandemic characterized by a plethora of diseases, of which those affecting the internal organs and nervous system can have severe, life-threatening consequences. Among the manifestations of the disease at the viral entry site, diseases in oral mucosa adnexa are rarely reported. This case report describes a COVID-19-associated aggravating parotid gland disease.

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Oral squamous cell carcinoma (OSCC) is one of the most prevalent cancers and frequently preceded by non-malignant lesions. Using Shifted-Excitation Raman Difference Spectroscopy (SERDS), principal component and linear discriminant analysis in native tissue specimens, 9500 raw Raman spectra of OSCC, 4300 of non-malignant lesions and 4200 of physiological mucosa were evaluated. Non-malignant lesions were distinguished from physiological mucosa with a classification accuracy of 95.

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Magnesium (Mg)-based biomaterials hold considerable promise for applications in regenerative medicine. However, the degradation of Mg needs to be reduced to control toxicity caused by its rapid natural corrosion. In the process of developing new Mg alloys with various surface modifications, an efficient assessment of the relevant properties is essential.

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Objectives: Salivary gland tumors are predominantly benign and frequently localized in the parotid gland (P). The treatment consists primarily of surgical removal; however, the appropriate extent remains a subject of debate. In suitable tumors, superficial parotidectomy (SP) may be substituted for less invasive partial superficial parotidectomy (PSP) (I C).

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Background: Digital learning environments have become very common in the training of medical professionals, and students often use such platforms for exam preparation. Multiple choice questions (MCQs) are a common format in medical exams and are used by students to prepare for said exams.

Objective: We aimed to examine whether particular learning activities contributed more strongly than others to users' exam performance.

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Aim: The purpose of this study was to survey the current opinions of hospitals and medical practices concerning the perioperative management of patients undergoing direct oral anticoagulant therapy (DOAC) and discuss recommendations for the clinical practice.

Materials And Methods: A questionnaire with 13 topics and multiple ordinal-polytomous subitems was designed and sent to 120 Departments of Oral and Maxillofacial Surgery in Austria, Switzerland and Germany, as well as to 85 oral and maxillofacial/oral surgeons in medical offices in Hamburg, Germany. The data were statistically evaluated by Chi-square, Fisher's exact and Jonckheere-Terpstra tests.

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Background: This study seeks to identify those factors that influence the pre-therapeutic speech intelligibility in patients with oral squamous cell carcinoma (OSCC).

Method: A group of 172 patients (125 males, 47 females, mean age = 61 ± 11 a) with different OSCC stages ranging from T1 to T4 and N0 to N2 was examined for their speech intelligibility using a computerized measuring tool, and compared to a healthy reference group (30 males, 10 females, mean age = 59 ± 12 a).

Results: It was found that the pre-therapeutic speech intelligibility in patients with OSCC is decreased when compared to a healthy collective.

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Background/aim: Osteoid osteoma (OO) is a benign tumor characterized by the excessive formation of unmineralized bone matrix. It is mostly located in the long bones of the lower extremities or the spine, but can also occur in atypical locations.

Patients And Methods: Here we report on a rare case of OO in the mandible in an 18-year-old male patient with a simultaneous finding of a pilomatrixoma in the parietal region.

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Background: Local anesthesia is an important skill and a prerequisite for most dental treatments. However, the step from theory to application on the patient is huge for the novice. Hence, a mannequin training model course was developed and implemented into the existing local anesthesia curriculum in undergraduate dental students.

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Purpose: Probe-based confocal laser endomicroscopy (pCLE) is a subcellular in vivo imaging technique capable of producing images that enable diagnosis of malign structural modifications in epithelial tissue. Images acquired with pCLE are, however, often tainted by significant artifacts that impair diagnosis. This is especially detrimental for automated image analysis, which is why said images are often excluded from recognition pipelines.

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Background/aim: Plasma electrolytic oxidation (PEO) is an established electrochemical treatment technique that can be used for surface modifications of metal implants. In this study we to treated titanium implants with PEO, to examine the resulting microstructure and to characterize adhesion and viability of cells on the treated surfaces. Our aim was to identify an optimal surface-modification for titanium implants in order to improve soft-tissue integration.

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Oral Squamous Cell Carcinoma (OSCC) is a common type of cancer of the oral epithelium. Despite their high impact on mortality, sufficient screening methods for early diagnosis of OSCC often lack accuracy and thus OSCCs are mostly diagnosed at a late stage. Early detection and accurate outline estimation of OSCCs would lead to a better curative outcome and a reduction in recurrence rates after surgical treatment.

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Aims: Complete maxillary edentulism and prosthetic rehabilitation with removable full dentures are known to affect speech intelligibility. The aim of this study was to prospectively investigate the long-term effect of time on speech intelligibility in patients being rehabilitated with newly fabricated full maxillary dentures.

Materials And Methods: Speech was recorded in a group of 14 patients (male = 9, female = 5; mean age ± standard deviation [SD] = 66.

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The use of remote optical feedback systems represents a promising approach for minimally invasive, nerve-sparing laser surgery. Autofluorescence properties can be exploited for a fast, robust identification of nervous tissue. With regard to the crucial step towards clinical application, the impact of laser ablation on optical properties in the vicinity of structures of the head and neck has not been investigated up to now.

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Objectives: Herpes labialis viral reactivation has been reported following dental procedures, but the incidence, characteristics and outcomes of delayed peripheral facial nerve palsy following dental work is poorly understood. Herein we describe the unique features of delayed facial paresis following dental procedures.

Materials And Methods: An institutional retrospective review was performed to identify patients diagnosed with delayed facial nerve palsy within 30 days of dental manipulation.

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Peripheral nerve injury is a common clinical entity, which may arise due to traumatic, tumorous, or even iatrogenic injury in craniomaxillofacial surgery. Despite advances in biomaterials and techniques over the past several decades, reconstruction of nerve gaps remains a challenge. Autografts are the gold standard for nerve reconstruction.

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Background: Confocal laser endomicroscopy (CLE) is an optical biopsy method allowing in vivo microscopic imaging at 1000-fold magnification. It was the aim to evaluate CLE in the human oral cavity for the differentiation of physiological/carcinomatous mucosa and to establish and validate, for the first time, a scoring system to facilitate CLE assessment.

Methods: The study consisted of 4 phases: (1) CLE-imaging (in vivo) was performed after the intravenous injection of fluorescein in patients with histologically confirmed carcinomatous oral mucosa; (2) CLE-experts (n = 3) verified the applicability of CLE in the oral cavity for the differentiation between physiological and cancerous tissue compared to the gold standard of histopathological assessment; (3) based on specific patterns of tissue changes, CLE-experts (n = 3) developed a classification and scoring system (DOC-Score) to simplify the diagnosis of oral squamous cell carcinomas; (4) validation of the newly developed DOC-Score by non-CLE-experts (n = 3); final statistical evaluation of their classification performance (comparison to the results of CLE-experts and the histopathological analyses).

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In the present study, the elemental compositions of fat and nerve tissue during their plasma mediated laser ablation are studied in the context of tissue differentiation for laser surgery applications by using Laser-Induced Breakdown Spectroscopy (LIBS). Tissue samples of porcine fat and nerve were prepared as ex vivo experimental objects. Plasma mediated laser ablation is performed using an Nd : YAG laser in open air and under normal stray light conditions.

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The protection of sensitive structures (e.g., nerves) from iatrogenic damage is of major importance when performing laser surgical procedures.

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