Application of Fractal Dimension and Texture Analysis to Evaluate the Effectiveness of Treatment of a Venous Lake in the Oral Mucosa Using a 980 nm Diode Laser-A Preliminary Study

A Novel Air-Cooled Nd:YAG Laser for the Treatment of the Venous Lakes of the Lips

Objective: To evaluate the therapeutic effect of a novel air-cooled Nd:YAG laser in the venous lakes of the lips (VLL). Background: The thermal injury is one of the most important issues during laser therapy for venous lakes. Methods: Six pieces of fresh pork livers were used to provide 30 regions with a diameter of 6 mm for experiment in vitro, among which 15 regions were treated by Nd:YAG laser with air cooling until the tissue turned gray-white, whereas the rest were treated without air cooling as control. The operation time of laser irradiation, the degree of temperature increase, and the depth of coagulation tissue were compared between two groups. Then, 60 VLL patients were selected for Nd:YAG laser treatment with or without air cooling. The operation time of laser irradiation, the degree of temperature increase, the postoperative pain visual analog scale (VAS) score, and the percentage of lesions removed within 1 month were compared. Results: In tissue studies, the treated group showed a longer operation time of laser irradiation (p < 0.01), a lower degree of temperature increase (p < 0.01), and there was no significant statistical difference in the depth of coagulation tissue (p = 0.624). In clinical studies, the treated group showed a longer operation time of laser irradiation (p < 0.01), a lower degree of temperature increase (p < 0.01), and a lower VAS score on the 1st and 2nd day, compared with the control group (p < 0.01). Conclusions: Air cooling during Nd:YAG laser for the treatment of VLL can prolong the surgical time, but lowered tissue temperature and reduced patient pain within 2 days under the premise of ensuring the treatment effect.

Mechanical Properties, Fractal Dimension, and Texture Analysis of Selected 3D-Printed Resins Used in Dentistry That Underwent the Compression Test

Three-dimensional printing is finding increasing applications in today’s world. Due to the accuracy and the possibility of rapid production, the CAD/CAM (computer-aided design/computer-aided manufacturing) technology has become the most desired approach in the preparation of elements, especially in medicine and dentistry. This study aimed to compare the biomechanical properties, fractal dimension (FD), and texture of three selected materials used for 3D printing in dentistry. Three biomaterials used in 3D printing were evaluated. The materials were subjected to the compression test. Then, their mechanical features, FD, and texture were analyzed. All the tested materials showed different values for the studied properties. The only statistically insignificant difference was observed for the force used in the compression test. All three materials showed differences in width and height measurements. The difference in the decrease between the compression plates was also significant. For Dental LT Clear, the mean value was 0.098 mm (SD = 0.010), while for BioMed Amber it was 0.059 mm (SD = 0.019), and for IBT it was 0.356 mm (SD = 0.015). The nominal strain also differed between the materials. IBT had the highest mean value (7.98), while BioMed Amber had the smallest (1.31). FD analysis revealed that Dental LT Clear did not show differences in the structure of the material. The other two materials showed significant changes after the compression test. Texture analysis (TA) revealed similar results: BioMed Amber resin showed significantly less pronounced texture changes compared to the other two materials. BioMed Amber also showed the most stable mechanical properties, whereas those of IBT changed the most. Fractal analysis revealed that IBT showed significant differences from the other two materials, whereas TA showed that only Dental LT Clear did not show changes in its texture after the compression test. Before the compression, however, BioMed Amber differed the most when bone index was taken into account.

An Experimental Anodized and Low-Pressure Oxygen Plasma-Treated Titanium Dental Implant Surface-Preliminary Report

Chemical composition and physical parameters of the implant surface, such as roughness, regulate the cellular response leading to implant bone osseointegration. Possible implant surface modifications include anodization or the plasma electrolytic oxidation (PEO) treatment process that produces a thick and dense oxide coating superior to normal anodic oxidation. Experimental modifications with Plasma Electrolytic Oxidation (PEO) titanium and titanium alloy Ti6Al4V plates and PEO additionally treated with low-pressure oxygen plasma (PEO-S) were used in this study to evaluate their physical and chemical properties. Cytotoxicity of experimental titanium samples as well as cell adhesion to their surface were assessed using normal human dermal fibroblasts (NHDF) or L929 cell line. Moreover, the surface roughness, fractal dimension analysis, and texture analysis were calculated. Samples after surface treatment have substantially improved properties compared to the reference SLA (sandblasted and acid-etched) surface. The surface roughness (Sa) was 0.59-2.38 µm, and none of the tested surfaces had cytotoxic effect on NHDF and L929 cell lines. A greater cell growth of NHDF was observed on the tested PEO and PEO-S samples compared to reference SLA sample titanium.

Importance of the Right Protocol in Using a Diode Laser (980 nm) for Small Oral Vascular Malformation Treatment

Small vascular anomalies are commonly present on the lips and other areas of the oral mucosa. These lesions are also known as venous lake lesions, and they can be treated in many ways with surgical and non-surgical methods. Laser is an arising technique for this type of procedure and its use has been growing in dental practices in the last years. The technique that uses the diode laser delivers the energy in a non-contact treatment, leading to the coagulation of the lesion in a minimally invasive manner, and for this reason, there is less chance of developing scar formation. In this report, a 56-year-old female patient had a vascular lesion on her lower lip measuring about 3.0 mm in diameter. The patient reported having it for more than 10 years. A first approach using a high-power diode laser had already been done but with no success. At this time, the diode laser was used under local anesthesia, with a flexible quartz fiber held 2 to 3 mm from the lesion, using the continuous wave mode set, 1.0 W of power for 10 seconds, with an interval of 30 seconds to prevent heat damage to the adjacent tissue. The laser was applied until the lesion appeared white and with evidence of shrinkage. In this case, two rounds of irradiation were done. After a 30-day follow-up, the lesion was repaired with no signs of scars on the lip. The diode laser is an effective technique for treating this type of lesion, with many advantages, such as providing coagulation, excellent healing, no postoperative complication, and no need for suturing. Besides all, it is also a low-cost procedure, small lesions usually require only one appointment, and this treatment is also better accepted by the patients.

Fractal Dimension Analysis of Melanocytic Nevi and Melanomas in Normal and Polarized Light-A Preliminary Report

Clinical diagnosis of pigmented lesions can be a challenge in everyday practice. Benign and dysplastic nevi and melanomas may have similar clinical presentations, but completely different prognoses. Fractal dimensions of shape and texture can describe the complexity of the pigmented lesion structure. This study aims to apply fractal dimension analysis to differentiate melanomas, dysplastic nevi, and benign nevi in polarized and non-polarized light. A total of 87 Eighty-four patients with 97 lesions were included in this study. All examined lesions were photographed under polarized and non-polarized light, surgically removed, and examined by a histopathologist to establish the correct diagnosis. The obtained images were then processed and analyzed. Area, perimeter, and fractal dimensions of shape and texture were calculated for all the lesions under polarized and non-polarized light. The fractal dimension of shape in polarized light enables differentiating melanomas, dysplastic nevi, and benign nevi. It also makes it possible to distinguish melanomas from benign and dysplastic nevi under non-polarized light. The fractal dimension of texture allows distinguishing melanomas from benign and dysplastic nevi under polarized light. All examined parameters of shape and texture can be used for developing an automatic computer-aided diagnosis system. Polarized light is superior to non-polarized light for imaging texture details.

Texture Analysis in Diagnosing Skin Pigmented Lesions in Normal and Polarized Light-A Preliminary Report

The differential diagnosis of benign nevi (BN), dysplastic nevi (DN), and melanomas (MM) represents a considerable clinical problem. These lesions are similar in clinical examination but have different prognoses and therapeutic management techniques. A texture analysis (TA) is a mathematical and statistical analysis of pixel patterns of a digital image. This study aims to demonstrate the relationship between the TA of digital images of pigmented lesions under polarized and non-polarized light and their histopathological diagnosis. Ninety pigmented lesions of 76 patients were included in this study. We obtained 166 regions of interest (ROI) images for MM, 166 for DN, and 166 for BN. The pictures were taken under polarized and non-polarized light. Selected image texture features (entropy and difference entropy and long-run emphasis) of ROIs were calculated. Those three equations were used to construct the texture index (TI) and bone index (BI). All of the presented features distinguish melanomas, benign and dysplastic lesions under polarized light very well. In non-polarized images, only the long-run emphasis moment and both indices effectively differentiated nevi from melanomas. TA is an objective method of assessing pigmented lesions and can be used in automatic diagnostic systems.

Fractal Dimension and Texture Analysis of Lesion Autofluorescence in the Evaluation of Oral Lichen Planus Treatment Effectiveness

BACKGROUND

Oral Lichen planus (OLP) is a chronic inflammatory disease. Topical steroids are used as the treatment of choice. The alternative is photodynamic therapy (PDT). The study aimed to fabricate optimal biodegradable matrices for methylene blue or triamcinolone acetonide because of a lack of currently commercially available carriers that could adhere to the mucous.

METHODS

The study was designed as a 12-week single-blind prospective randomized clinical trial with 30 patients, full contralateral split-mouth design. Matrices for steroid and photosensitizer and laser device were fabricated. Fractal and texture analysis of photographs, taken in 405, 450, 405 + 450 nm wavelength, of lesions was performed to increase the objectivity of the assessment of treatment.

RESULTS

We achieved two total responses for treatment in case of steroid therapy and one in the case of PDT. Partial response was noted in 17 lesions treated using local steroid therapy and 21 in the case of PDT. No statistically significant differences were found between the effectiveness of both used methods. Statistically significant differences in fractal dimension before and after treatment were observed only in the analysis of photographs taken in 405 + 450 nm wavelength.

CONCLUSIONS

Photodynamic therapy and topical steroid therapy are effective methods for treating OLP. Using a carrier offers the possibility of a more predictable and effective method of drug delivery into the mucous membrane. Autofluorescence enables the detection of lesions especially at the early stage of their development.