PURPOSE:To evaluate the performance of support vector machine, multi‐layer perceptron and radial basis function neural network as auxiliary tools to identify keratoconus from Orbscan II maps.METHODS:A total of 318 maps were selected and classified into four categories: normal (n = 172), astigmatism (n = 89), keratoconus (n = 46) and photorefractive keratectomy (n = 11). For each map, 11 attributes were obtained or calculated from data provided by the Orbscan II. Ten‐fold cross‐validation was used to train and test the classifiers. Besides accuracy, sensitivity and specificity, receiver operating characteristic (ROC) curves for each classifier were generated, and the areas under the curves were calculated.RESULTS:The three selected classifiers provided a good performance, and there were no differences between their performances. The area under the ROC curve of the support vector machine, multi‐layer perceptron and radial basis function neural network were significantly larger than those for all individual Orbscan II attributes evaluated (p<0.05).CONCLUSION:Overall, the results suggest that using a support vector machine, multi‐layer perceptron classifiers and radial basis function neural network, these classifiers, trained on Orbscan II data, could represent useful techniques for keratoconus detection.

No abstract

Odontogenic myxoma is a rare tumor, often diagnosed during routine radiographs or when it is so severe that it causes pain, a noticeable increase in volume or tooth displacement and mobility. Young adults (25-30 years of life) are more often affected by the lesion but all ages are vulnerable. The mandible is more commonly involved than the maxilla and the tumors usually grow slowly and silently. However, growth can be rapid and destructive. The radiographic aspect of a myxoma is that of a uni or multilocular, radiolucent lesion reminiscent of honeycomb or soap bubbles, depending on its size. It is an expansive tumor that may cause displacement or resorption of the teeth involved. Microscopically, the tumor is composed of round and spindle cells, with a star arrangement, arranged in a loose abundant myxoid stroma, containing only a few collagen fibrils. The treatment of choice is radical surgical excision because myxomas are not encapsulated and tend to infiltrate the surrounding bone. However, small tumors can be treated by curettage. Periodic reassessment is required for at least five years due to the high rate of recurrence. Larger tumors may need to be treated using a more extensive resection with a safety margin. This study reports a clinical case of odontogenic myxoma in a child aged 7 years. The tumor was located in the posterior region of the mandible and was surgically treated with an en bloc resection with preservation of the base of the mandible. The follow-up of the case is ongoing and no recurrence has been observed to date.