Aim: Congenital hypodontia is one of the most frequent anomalies of the human dentition. Several symptoms are considered to indicate a predisposition to congenital hypodontia. The aim of the present study was to examine the prevalence of such symptoms in a group of patients undergoing orthodontic treatment. Materials and Method: The panoramic radiographs of 968 patients were evaluated. Each radiograph was examined for nine characteristic symptoms: absence of tooth buds, delayed mineralisation of tooth buds, hyperdontia, atypical position of tooth buds, microdontia, displaced teeth, taurodontism, increased distance between molar buds (only for permanent teeth) and infraposition of the primary molars. Results: Three hundred patients (31%) were found to have one or more symptoms of a disturbed development of the dentition. The most frequent symptoms were atypical position of tooth buds (15.5%), displaced teeth (10%), and the absence of buds for permanent teeth (7.5%). Seventy-two per cent of the patients had only one symptom and 28 per cent two or more. Displaced teeth were associated more frequently than aplasia with other symptoms. All other symptoms were found significantly (PConclusions: The initial detection of symptoms of a disturbed development of the dentition suggests that further developmental disturbances are likely to be encountered to some degree. Early recognition of those symptoms allows early application of preventive orthodontic measures. Keywords: disturbed odontogenesis, panoramic radiograph, hypodontia, hyperdontia, tooth displacement