Third Dentition Is the Main Cause of Premolar Supernumerary Tooth Formation

Abstract

While the prevalence of supernumerary teeth (ST) is high in permanent dentition, the etiology of ST in humans remains unclear. However, multiple murine models of ST have elaborated on dated mechanisms traditionally ascribed to ST etiology: one involves the rescue of rudimental teeth, and the second considers the contribution of odontogenic epithelial stem cells. It remains unclear whether these mechanisms of ST formation in mice are applicable to humans. The third dentition is usually regressed apoptotic—that is, the teeth do not completely form in humans. Recently, it was suggested that ST result from the rescue of regression of the third dentition in humans. The present investigation evaluates the proportion of collected general ST cases that evinced a third dentition based on the clinical definition of ST derived from the third dentition. We also investigated the contribution of SOX2-positive odontogenic epithelial stem cells to ST formation in humans. We collected 215 general ST cases from 15,008 patients. We confirmed that the general characteristics of the collected ST cases were similar to the results from previous reports. Of the 215 cases, we narrowed our analysis to the 78 patients who had received a computed tomography scan. The frequency of ST considered to have been derived from the third dentition was 26 out of 78 cases. Evidence of a third dentition was especially apparent in the premolar region, was more common in men, and was more likely among patients with ≥3 ST. SOX2-positive odontogenic epithelial stem cells within the surrounding epithelial cells of developing ST were observed in non–third dentition cases and not in third dentition cases. In conclusion, the third dentition is the main cause of ST in humans. The odontogenic epithelial stem cells may contribute to ST formation in cases not caused by a third dentition.

Development of tooth regenerative medicine strategies by controlling the number of teeth using targeted molecular therapy

“…In recent years, there have been many studies of stem cells in relation to the development of regenerative therapies for various organs such as nephrons (the functional units of the kidney) or the pituitary gland [73,74]. We also demonstrated that OESCs may contribute to supernumerary teeth formation in cases not caused by third dentitions [55]. Multiple supernumerary teeth derived from odontogenic epithelial stem cells have the potential to erupt following the eruption of permanent teeth without dental caries and periodontal disease (Fig.…”

“…We have previously reported that this clinical definition would apply to at least one-third of non-syndromic multiple supernumerary teeth [54]. Recently, our investigation evaluated the proportion of collected general supernumerary teeth cases that evinced a third dentition based on the clinical definition of supernumerary teeth derived from the third dentition [55]. The frequency of supernumerary teeth considered to have been derived from the third dentition was 26 out of 78 cases [55].…”

“…Recently, our investigation evaluated the proportion of collected general supernumerary teeth cases that evinced a third dentition based on the clinical definition of supernumerary teeth derived from the third dentition [55]. The frequency of supernumerary teeth considered to have been derived from the third dentition was 26 out of 78 cases [55]. Evidence of a third dentition was especially apparent in the premolar region, was more common in men, and more likely to occur in patients with three or more supernumerary teeth [55].…”

“…The frequency of supernumerary teeth considered to have been derived from the third dentition was 26 out of 78 cases [55]. Evidence of a third dentition was especially apparent in the premolar region, was more common in men, and more likely to occur in patients with three or more supernumerary teeth [55]. It was suggested that the third dentition is the main cause of supernumerary teeth in humans.…”

Intervention for Multiple Supernumerary Premolars in a Teenager: Case Report

“…Recently, the term "third dentition" has been proposed to describe supernumerary teeth that develop and appear after the completion of the usual configuration of 32 permanent teeth, representing a dental anomaly of number in the human species (1)(2)(3). Although this clinical phenomenon is relatively frequent in the global population (with an estimated prevalence between 1.5 and 3.8% in permanent dentition), the exact etiology of this anomaly remains unknown (2,4,5).…”