Numerical anomalies, either addition or deletion, are quite a common findings in human dentition. However, it is extremely rare to find both hypodontia and hyperdontia simultaneously in the same individual. This condition is referred as concomitant hypohyperdontia (CHH). Aetiology of this condition is still obscure. The prevalence of CHH has been reported to be between 0.002% and 3.1%. This case report highlights a rare occurrence of bimaxillary CHH represented by the absence of both mandibular central incisors and presence of two supernumerary teeth in the maxillary anterior segment. The rarity of such condition of mixed hypodontia as well as hyperdontia in single human dentition prompted the author to report the case.
The presence of supernumerary teeth in the premaxillary region may cause a variety of pathological effects. This study was carried out to determine the various aspects of supernumerary teeth in the premaxillary region, particularly the effects of the supernumerary teeth on the permanent incisors and surrounding tissues. Approximately 20 percent of the patients (n = 49) with supernumerary teeth did not present with any abnormality. A high proportion of patients (37.9 percent) had delayed or failure of eruption of permanent teeth and 24.1 percent had rotation or displacement of permanent teeth. Other effects observed were median diastema and cystic changes around the unerupted supernumerary tooth. The high proportion of pathological effects seen showed that early diagnosis of the anomaly is important to intercept damage to the adjacent normal teeth and surrounding tissues. However, no cases of root resorption of the permanent teeth due to the presence of supernumeraries were observed.