Early diagnosis of neurofibromatosis is significant to start the multidisciplinary approach of this type of patient. This syndrome may be first identified in pediatric dental care. This study is about a 9-year-old patient who was diagnosed with neurofibromatosis type 1 from a plexiform neurofibroma displayed in the left hemi-maxilla. From the microscopic diagnosis of the lesion the investigation of other related injuries began, according to the diagnostic criteria of the National Institute of Health (NIH), leading to the diagnosis of systemic alterations. The parental awareness about the condition and the establishment of multidisciplinary care are important for the treatment to be more conservative and the patient has fewer complications with better quality of life. The use of the diagnostic criteria in this case shows how methodization is important for reaching more accurate and reliable diagnoses.