ObjectiveTo discuss the reasons for misdiagnosis of supernumerary nasal teeth.MethodsClinical data of four supernumerary nasal tooth patients were analysed retrospectively at visits to our otolaryngology department between 2005 and 2018.ResultsAll four patients were male and had a supernumerary nasal tooth in the right nasal cavity. Three of the four patients had previously been misdiagnosed. All the supernumerary nasal teeth were surrounded by granulation tissue or hypertrophic nasal mucosa, and were subsequently confirmed by computed tomography and endoscopy. The granulation tissue or hypertrophic nasal mucosa was removed using microwave ablation, and the supernumerary nasal teeth successfully removed by endoscopy.ConclusionSupernumerary nasal teeth are rare, and are usually misdiagnosed because such teeth are surrounded by hypertrophic nasal mucosa or granulation tissue. They can be confirmed by computed tomography and endoscopy.