Supernumerary teeth in permanent dentition are influenced by hereditary and environmental, having clinical variations such as location, number and morphology. Parapremolars can be found as a single supernumerary tooth or as multiple, usually in the lower jaw, sometimes in association with other types of supernumerary teeth. Familial inheritance often involves more than one generation. This paper presents a case of two brothers, one with only one parapremolar and a good oral status and hygiene, the other with poor hygiene, multiple parapremolars and one mesiodens, causing various complications. The aim of this paper is to show the presence of parapremolars in brothers with no other medical relevant history, located in the same site, and to point the influence of genetic factors in the etiology of supernumerary teeth. Along with a review of the literature, this article shows the importance of an early diagnosis and follow-up using successive panoramic radiographs of such cases, in order to limit or prevent the inflammatory, carious, periodontal and occlusal complications that can seriously affect both the jaws and the normal dentition.