Raman difference spectroscopy and U-Net convolutional neural network for molecular analysis of cutaneous neurofibroma.

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. Here, we introduce Shifted-Excitation Raman Spectroscopy in combination with deep neural networks for the future perspective of objective, real-time diagnosis, and guided surgical ablation. The obtained results are validated through established histological methods. In this study, we evaluated the discrimination between cutaneous neurofibroma (n = 9) and adjacent physiological tissues (n = 25) in 34 surgical pathological specimens ex vivo at a total of 82 distinct measurement loci. Based on a convolutional neural network (U-Net), the mean raw Raman spectra (n = 8,200) were processed and refined, and afterwards the spectral peaks were assigned to their respective molecular origin. Principal component and linear discriminant analysis was used to discriminate cutaneous neurofibromas from physiological tissues with a sensitivity of 100%, specificity of 97.3%, and overall classification accuracy of 97.6%. The results enable the presented optical, non-invasive technique in combination with artificial intelligence as a promising candidate to ameliorate both, diagnosis and treatment of patients affected by cutaneous neurofibroma and NF1.

Outcomes and influencing factors of dental implants in fibula, iliac crest, and scapula free flaps: a retrospective case-control study.

PURPOSE: Reconstruction with vascularized bone grafts after ablative surgery and subsequent dental rehabilitation with implants is often challenging; however, it helps improve the patient's quality of life. This retrospective case-control study aimed to determine the implant survival/success rates in different vascularized bone grafts and potential risk factors. METHODS: Only patients who received implants in free vascularized bone grafts between 2012 and 2020 were included. The free flap donor sites were the fibula, iliac crest, and scapula. The prosthetic restoration had to be completed, and the observation period had to be over one year after implantation. Implant success was defined according to the Health Scale for Dental Implants criteria. RESULTS: Sixty-two patients with 227 implants were included. The implant survival rate was 86.3% after an average of 48.7 months. The causes of implant loss were peri-implantitis (n = 24), insufficient osseointegration (n = 1), removal due to tumor recurrence (n = 1), and osteoradionecrosis (n = 5). Of all implants, 52.4% were classified as successful, 19.8% as compromised, and 27.8% as failed. Removal of osteosynthesis material prior to or concurrent with implant placement resulted in significantly better implant success than material not removed (p = 0.035). Localization of the graft in the mandibular region was associated with a significantly better implant survival (p = 0.034) and success (p = 0.002), also a higher Karnofsky Performance Status Scale score with better implant survival (p = 0.014). CONCLUSION: Implants placed in vascularized grafts showed acceptable survival rates despite the potential risk factors often present in these patient groups. However, peri-implantitis remains a challenge.

Characterization of Dental Pulp Stem Cell Populations in the Teeth of Patients With Neurofibromatosis Type 1 - Therapeutic Potential for Bone Tissue Engineering.

BACKGROUND/AIM: Neurofibromas (NF) are the most common benign nerve sheath tumors in the tongue, gingiva, major salivary glands, and jaw bones. Nowadays, tissue engineering is a revolutionary technique for reconstructing tissues. To explore the feasibility of using stem cells derived from NF teeth to treat orofacial bone defects, the differences in cell biological properties between an NF teeth group and Normal teeth group. PATIENTS AND METHODS: The intra-dental pulp tissues from each tooth were extracted. The cell survival rates, morphology, proliferation rates, cell activity, and differentiation abilities were contrastively analyzed between the NF teeth group and Normal teeth group. RESULTS: Between the two groups, there were no differences in the primary generation (P0) cells (p>0.05), the cell yield, and the time required for the cells to grow out of the pulp tissue and attach to the culture plate. Furthermore, no differences were found at the first generation (passage) between the two groups in colony formation rate and cell survival rate. The proliferation capacity, cell growth curve, and surface marker expression of dental pulp cells was not altered in the third generation (p>0.05). CONCLUSION: Dental pulp stem cells from NF teeth were successfully obtained and were not different from normal dental pulp stem cells. Although, clinical research using tissue-engineered bone to repair bone defects is still in its infancy, it will eventually enter the clinic and become a routine means of bone defect reconstruction treatment as related disciplines and technologies develop.

Evaluation of the sense of taste and smell in patients with Neurofibromatosis Type 1.

OBJECTIVE: The objective of this study was to determine if patients with Neurofibromatosis Type 1 (NF1) have an impaired sense of smell or taste. Neurofibromin, the NF1gene protein product is ubiquitous in the body and is especially associated with the development of neurogenetic structures. Lately enlarged olfactory bulbs have been described in patients with NF1. Until now, there is no study to evaluate the sense of smell and taste in patients with NF1. METHOD: This study has been approved by the Hamburg Ethics committee. An evaluation of the sense of smell and taste was undertaken in 26 patients with NF1 using the Burghart Sniffin' Sticks. Three patients were excluded due to a prior infection with the Corona virus. As a control group the same examination was performed in healthy individuals (same sex/ same age as the NF1 patients) by the same examiner. RESULTS: The results show a normal sense of smell in patients with NF1. The morphologic finding of enlarged olfactory bulbs seem to have no functional equivalent. However, 8 out of 23 patients with NF1 had difficulties identifying at least one taste flavor. In total 9.8% of possible taste qualities were misidentified. In the healthy control group, all taste qualities were identified correctly. Considering each taste quality as separate case, a significant difference in the taste function was identified based on Fisher's exact test (p=0.003). CONCLUSION: The current study does not show a correlation between NF1 and an impaired sense of smell. Yet significant reduction in the sense of taste was found in the patients with NF1. Further research will have to be conducted to find the underlying causal pathways. CLINICAL RELEVANCE: NF1 is recently being acknowledged not only for its' macroscopic aesthetic and functional impairments, but also as a neurodevelopmental disorder. Evaluating the neural structures in regard to their function is a first step in understanding more about the disease.

A new surgical approach to treatment of bilateral syngnathia in a patient with popliteal pterygium-syndrome.

This case describes the treatment of syngnathia with a popliteal-pterygium syndrome. Although short-term successful surgical treatment has been described in literature, long-term follow up is essential, as the mouth opening limitations can be repetitively reoccurring. This requires new, individual treatment strategies as demonstrated in this case. A young patient is shown, who is successfully undergoing an alloplastic temporomandibular joint replacement to improve mouth opening, increasing the posterior airway space and facilitating the food intake.

A Connective Tissue Neoplasm of the Mandibular Angle Mimicking Stafne's Bone Cavity on Panoramic View.

BACKGROUND: When assessing sharply delineated bone lesions of the mandibular angle on X-rays, numerous diagnoses must be considered. The static bone cavity (Stafne's bone cavity, SBC) is a harmless lingual bone depression of the mandibular angle that usually does not require any treatment. It is essential to differentiate this bone deformity from other lesions that may require treatment. CASE REPORT: The 22-year-old patient was referred for further diagnosis and therapy after osteolysis of the mandible was noticed on a panoramic view (PV). The location and size of the lesion was typical of SBC. Only the three-dimensional representation of the lesion on cone beam computed tomographs revealed an intraosseous lesion. Histological examination of the lesion provided evidence of a fibrous neoplasm. CONCLUSION: The typical image of SBC is ambiguous on plain radiographs such as PV. The radiological diagnosis of the lesion should be based on the representation of the region of interest in different planes.

Lingual Mandibular Bone Depression.

BACKGROUND/AIM: In the area of the jaw angle, osteolytic lesions can occur, the differential diagnosis of which can be difficult and require very different therapeutic measures. One of these lesions is lingual mandibular bone depression (LMBD). The aim of this study was to present the characteristics of the lesion in a group of LMBD patients and to differentiate it from other lesions. PATIENTS AND METHODS: Radiological images of 21 patients with LMBD were examined. RESULTS: The majority of LMBDs were located in the jaw angle. On cross-sectional images, the lesion could be distinguished from salivary tissue (n=2). One case of LMBD had an impact on the course of the fracture line in the mandibular trauma. CONCLUSION: LMBD is a developmental disorder of the mandible and only rarely of pathological importance. Imaging the lesion with cross-sectional images is preferable to using plain X-ray projections. In some cases, surgical exploration is essential for diagnosis.