Introduction: Supernumerary teeth are dental germs formed in excess by hyperactivity of the dental lamina in the beginning of the odontogenesis. The use of nitrous oxide in Dentistry is one of the vastly used types of sedations, once it has a good sedative effect, thus, decreasing patients’ anxiety and fear and also contributing to a slight analgesic effect. Aim: This work aims to report the case of a patient that presents four supernumerary teeth, being classified as fourth molars. It proceeded with a surgery to remove them with the aid of conscious sedation, emphasising the most important aspects and the main divergences. Case report: Patient male, 35 years old, black, from Juazeiro do Norte – Ceará, Brazil, went to the private clinic to remove the third and fourth molars in order to favour an orthodontic treatment. Dental extraction of all the impacted dental elements was performed under sedative effects of nitrous oxide. Discussion: The presence of supernumerary teeth in maxilla and mandible has higher pathogenic risks, once they can become cysts and tumours.Therefore it is indicated to remove those teeth. The use of nitrous oxide is highly important to enhance conditions during procedures, if patients present anxiety or fear of dentists. Conclusion: We conclude that the removal of the dental elements was adequate as for the orthodontic treatment and low risk of infections, as well as the use of nitrous oxide as a sedative, once the patient presented an important degree of anxiety.