Fusion is a developmental dental anomaly in which asingle large tooth is formed from the germs of two normally adjacentteeth. The incidence of fused teeth is 0.1-0.3% in the permanent and0.5-2.5% in the primary dentition, and fusion is usually unilateral. Anot her dental developmental anomaly, dens evaginatus, is defined as anaccessory tubercle, consisting of enamel, dentine, and pulp. A 17-year old female patient was referred to our clinic with a complaint of painand swelling in the maxilla bilateral premolar regions. After the eva luation of clinical, two, and three-dimensional radiological findings,bilateral complete and incomplete fusion of the maxillary first premo lar and impacted supernumerary teeth was diagnosed, which is a rarecondition. Also, the left impacted supernumerary tooth had another de velopmental anomaly, dens evaginatus, that makes the case more inte resting. Treatment options were recommended to the patient, whorequested the extraction of the teeth, and the relevant teeth were ext racted. Careful clinical and radiographic examinations should be per formed for the diagnosis and treatment of fusion that may causefunctional and esthetic problems.