ATAPUERCA, SPAIN—A human jaw recovered from El Mirador Cave has a rare supernumerary tooth that has been examined with Cone-Beam Computed Tomography (CBCT) by a team of researchers from the Institut Català de Paleoecologia Humana I Evolució Social (IPHES), the Universitat Rovira I Virgili (URV), and the Faculty of Dentistry at the Universitat Internacional de Catalunya (UIC). Human dentition is usually composed of three molars in each side of the upper and lower jaw. This jaw, which probably belonged to a 40-year-old man who lived between 4,760 and 4,200 years ago, had a fourth molar in the lower mandible. “In the case of archaeological populations there are very few studied and published examples of supernumerary teeth. Therefore, it is a novelty,” Marina Lozano, an IPHES researcher and a professor at URV, said in a press release. The Neolithic diet of starchy carbohydrates and a lack of dental hygiene increased the occurrence of dental caries among early farmers. These teeth show signs of severe dental wear, decay, abscesses, pulpitis, periodontal disease, tooth-picking marks in an upper molar, and arthritis of the temporomandibular joint. “This diagnosis confirms that oral health from the Neolithic became worse in agriculture and livestock populations,” she explained. To read about another instance of unusual ancient dentition, see "The Case of the Missing Incisors."