Abstract
Background & Aims: A research shows that lower right second premolar was among the most frequently missing teeth (3.7%). Only (0.08%) of the research subjects had six or more missing tooth (Oligodontia). The purpose of this study is: Diagnosis of developmental defects of the dental hard tissues and their treatment.
Case summary: In order to conduct the study, we received pre-declared informed consent from the parents of a patient who is 10 (ten) years old. The study was conducted in 2019-2020. Caries status was evaluated using both clinical and radiographic data and assessed as D1/D2 – enamel lesion and D3/D4 as dentin lesion. Dental status and treatment. We defined the diagnoses: Caries medioocclussalys d3b on tooth 65; Caries distoocclussalys d3b on tooth 64. Caries was treated by fillings of the cavities with a Direct compomer. Deep non-mineralized fissure of tooth 36 with subsequent application of sealant. Orthopantomography also shows Hypodontia premolar dentis teeth (35, 44, 45); Hypodontia dentis (18, 28, 38, 48 D: Oligodontia). Diagnosis: 10-year-old boy with hypoplasia of the upper permanent incisors and Oligodontia. The patient was treated with non-invasive and invasive methods of treatment. The study was conducted at the University Medical and Dental Center, Varna, Bulgaria. Conclusion: 1. Developmental anomalies associated with tooth agenesis include delayed tooth formation, prolonged primary tooth exfoliation, retained primary teeth, interdental spacing. 2. Enamel hypoplasia increases the risk of developing dental caries. 3. Early diagnosis allows optimal patient management and treatment planning and can reduce complications of the planned treatment.

Key words: Tooth anomalies, Panoramic radiograph, Tooth agenesis, Oligodontia