An artificial neural network based approach for predicting the proton beam spot dosimetric characteristics of a pencil beam scanning technique.

Utilising Machine Learning (ML) models to predict dosimetric parameters in pencil beam scanning proton therapy presents a promising and practical approach. The study developed Artificial Neural Network (ANN) models to predict proton beam spot size and relative positional errors using 9000 proton spot data. The irradiation log files as input variables and corresponding scintillation detector measurements as the label values. The ANN models were developed to predict six variables: spot size in thex-axis,y-axis, major axis, minor axis, and relative positional errors in thex-axis andy-axis. All ANN models used a Multi-layer perception (MLP) network using one input layer, three hidden layers, and one output layer. Model performance was validated using various statistical tools. The log file recorded spot size and relative positional errors, which were compared with scintillator-measured data. The Root Mean Squared Error (RMSE) values for the x-spot and y-spot sizes were 0.356 mm and 0.362 mm, respectively. Additionally, the maximum variation for the x-spot relative positional error was 0.910 mm, while for the y-spot, it was 1.610 mm. The ANN models exhibit lower prediction errors. Specifically, the RMSE values for spot size prediction in the x, y, major, and minor axes are 0.053 mm, 0.049 mm, 0.053 mm, and 0.052 mm, respectively. Additionally, the relative spot positional error prediction model for the x and y axes yielded maximum errors of 0.160 mm and 0.170 mm, respectively. The normality of models was validated using the residual histogram and Q-Q plot. The data over fit, and bias were tested using K (k = 5) fold cross-validation, and the maximum RMSE value of the K fold cross-validation among all the six ML models was less than 0.150 mm (R-Square 0.960). All the models showed excellent prediction accuracy. Accurately predicting beam spot size and positional errors enhances efficiency in routine dosimetric checks.

Knowledge, awareness, and practices of complementary and alternative medicine for oral health-care management among dental students.

OBJECTIVE: The objective of this study is to assess the awareness and practices of complementary and alternative medicine (CAM) for oral health-care management among dental students. MATERIALS AND METHODS: A cross-sectional study was conducted in 200 dental students of final year and internship selected by simple random sampling using a close-ended questionnaire. RESULTS: Among the total respondents, 52% were females and 48% were males. Nearly, 14% of the students were not aware of the different categories of the CAM and 12% of them were not aware of its implication in oral health-care management. CONCLUSION: Majority of the students was aware of CAM, yet they do not follow the use of the same for their patient's oral health-care management. Hence, a small provision regarding the knowledge of CAM should be imposed under the undergraduate curriculum for the dental students so that it should be implemented in their practice in future.

Facial Palsy, a Disorder Belonging to Influential Neurological Dynasty: Review of Literature.

Facial paralysis is one of the common problem leading to facial deformation. Bell's palsy (BP) is defined as a lower motor neuron palsy of acute onset and idiopathic origin. BP is regarded as a benign common neurological disorder of unknown cause. It has an acute onset and is almost always a mononeuritis. The facial nerve is a mixed cranial nerve with a predominant motor component, which supplies all muscles concerned with unilateral facial expression. Knowledge of its course is vital for anatomic localization and clinical correlation. BP accounts for approximately 72% of facial palsies. Almost a century later, the management and etiology of BP is still a subject of controversy. Here, we present a review of literature on this neurologically significant entity.

Myths and misconceptions in general public toward ocular complications followed by the removal of upper teeth.

INTRODUCTION: The upper jaw forms the floor of the maxillary sinus and the upper teeth are continuous with the whole midface and cranium, therefore while treating these teeth, it is important for the practitioner to consider the possibility of ocular complications. Ocular disturbances such as blurring of vision, mydriasis, ptosis, diplopia, enophthalmos, miosis, and blindness are rare complications due to intraoral local anesthesia. So far at present, the general population is having myths and misconceptions regarding the extraction of teeth and vision loss; hence, we evaluated the same. METHODS: A cross-sectional prospective survey targeting the general public was conducted using a self-administered questionnaire. A total of 300 standardized self-administered questionnaires were given and the data were analyzed. RESULTS: Out of 300 patients, 148 were educated and 152 were uneducated. The study population was analyzed based on their age, sex, and literacy, i.e. the level of education. Seventy-six percent of uneducated and 48% of educated groups had false belief of ocular complications followed by the removal of upper teeth and among them uneducated females of older age group showed higher prevalence. CONCLUSION: The general public's knowledge about ocular complications due to tooth extraction in our study group is not adequate and needs improvement. Although the practice of informing by dentists is satisfactory, there is a need for creating awareness in the general public against such complications.

Evaluation of dose perturbation at the interface of two different density medium using GAFCHROMIC film EBT2 and Monte Carlo code EGSnrc for Co-60 beam.

INTRODUCTION: Accurate dosimetry at the interface of two different density medium (e.g., air cavity in the head and neck cancers and lungs in thoracic region) is a major cause of concern in external beam radiation therapy. It has been observed that there is dose variation in and around air cavities, which occur as a result of the loss of both longitudinal and lateral electronic equilibrium. Heterogeneous structures with spatial differences in functionality and sensitivity for radiation pose challenge to radiation dosimetry. This study is an attempt to evaluate the dose perturbations produced at the interface of two medium for C0-60 gamma radiation. MATERIALS AND METHODS: Low density polyethene foam has been used to mimic air cavity. GAFCHROMIC EBT2 dosimetry film was used for the measurement of dose at different locations. Simulation studies were performed using DOSRZnrc user code that comes with EGSnrc V4 2.4.0. Cylindrical geometry is used for all the simulations. RESULTS AND DISCUSSION: We observed significant variation in dose for smaller fields. There is a dose build down in the backward region and a dose build up in the forward direction. In the region of electronic disequilibrium, dose reduction near interface (proximal end) will have negative impact if target region is embedded there, on the contrary, it would be beneficial if there is normal tissue/critical organ adjacent to it.

In vitro caries-preventive effect of fluoridated orthodontic resins against cariogenic challenge stimulation.

AIM: The aim of the present study was to evaluate the in vitro caries preventive effect of fluoridated orthodontic resins under pH cycling with two types of acid demineralizing saliva. MATERIALS AND METHODS: Brackets were bonded to 120 extracted human premolars, using Rely-a-bond (n = 40), Tru- Bond (n = 40) and Ortho-one (n = 40) orthodontic bonding agents. Each group of resin was divided into 2 subgroups (n = 20): immersion in remineralizing artificial saliva for 14 days and acid saliva with pH 4.3. After 14 days of pH cycling the caries preventive effect on the development of white spot lesion was evaluated considering the presence of inhibition zones to white spot lesions using two scores: 0 = absence and 1 = presence. Kruskal-Wallis ANOVA and Mann-Whitney U tests were used. RESULTS: Formation of white spot lesions was observed only under pH cycling using acid saliva with pH 4.3; with Rely-a-bond and Tru-Bond being significantly more effective in preventing the appearance of white spot lesions effect than Ortho-one. CONCLUSION: The acidity of the demineralizing solution influenced the formation of white spot lesions around orthodontic brackets under highly cariogenic conditions. Rely-a-bond and Tru-bond presented higher caries-preventive effect than Orthoone. CLINICAL SIGNIFICANCE: The development of fluoride-containing materials cannot be regarded as a permanent means to control dental caries lesions, but a complement along with other preventive methods.

Microbial colonization and their relation with potential cofactors in patients with denture stomatitis.

AIM: To determine microbial prevalence in the mucous membrane and prosthesis of denture wearers with and without denture stomatitis and to study its relationship with potential clinical cofactors. MATERIALS AND METHODS: Saliva was collected from 200 patients (100 female and 100 male) wearing dental prosthesis for measurement of pH. Oral samples of the mucous membrane and of dentures were taken with sterile swab for microbiological analysis. Medical and dietary history of the subjects was recorded. Chi-square test and analysis of varience were used for statistical analysis. RESULTS: Diabetes, hypertension and high carbohydrate ingestion was observed in majority of patients. The pH average in saliva was of 5.1. The presence of C. albicans, S. aureus and S. mutans in the mucous membrane was of 55.4, 56.4 and 63.6% respectively. C. albicans was isolated in 69.7% from the prosthesis, whereas S. aureus and S. mutans were isolated in 45.3%. The isolation of C.albicans was more frequent in patients with denture stomatitis. CONCLUSION: C. albicans, S. aureus and S. mutans frequently colonize the oral mucous of denture wearers. This is more frequently observed in patients with denture stomatitis. CLINICAL SIGNIFICANCE: Denture stomatitis is associated to Candida albicans, different bacteria and other cofactors, such as salivary pH, carbohydrate ingestion, systemic illnesses and medication.

Antimicrobial activity of commercially available essential oils against Streptococcus mutans.

INTRODUCTION: Many essential oils have been advocated for use in complementary medicine for bacterial and fungal infections. However, few of the many claims of therapeutic efficacy have been validated adequately by either in vitro testing or in vivo clinical trials. OBJECTIVE: To study the antibacterial activity of nine commercially available essential oils against Streptococcus mutans in vitro and to compare the antibacterial activity between each material. METHODOLOGY: Nine pure essential oils; wintergreen oil, lime oil, cinnamon oil, spearmint oil, peppermint oil, lemongrass oil, cedarwood oil, clove oil and eucalyptus oil were selected for the study. Streptococcus mutans was inoculated at 37ºC and seeded on blood agar medium. Agar well diffusion assay was used to measure antibacterial activity. Zone of inhibition was measured around the filter paper in millimeters with vernier caliper. RESULTS: Cinnamon oil showed highest activity against Streptococcus mutans followed by lemongrass oil and cedarwood oil. Wintergreen oil, lime oil, peppermint oil and spearmint oil showed no antibacterial activity. CONCLUSION: Cinnamon oil, lemongrass oil, cedarwood oil, clove oil and eucalyptus oil exhibit antibacterial property against S. mutans. CLINICAL SIGNIFICANCE: The use of these essential oils against S. mutans can be a viable alternative to other antibacterial agents as these are an effective module used in the control of both bacteria and yeasts responsible for oral infections.