Count Me in, Count Me out: Regulation of the Tooth Number via Three Directional Developmental Patterns

Abstract

Tooth number anomalies, including hyperdontia and hypodontia, are common congenital dental problems in the dental clinic. The precise number of teeth in a dentition is essential for proper speech, mastication, and aesthetics. Teeth are ectodermal organs that develop from the interaction of a thickened epithelium (dental placode) with the neural-crest-derived ectomesenchyme. There is extensive histological, molecular, and genetic evidence regarding how the tooth number is regulated in this serial process, but there is currently no universal classification for tooth number abnormalities. In this review, we propose a novel regulatory network for the tooth number based on the inherent dentition formation process. This network includes three intuitive directions: the development of a single tooth, the formation of a single dentition with elongation of the continual lamina, and tooth replacement with the development of the successional lamina. This article summarizes recent reports on early tooth development and provides an analytical framework to classify future relevant experiments.

Endoscopic Surgical Approach for a Mesiodens in the Nasal Cavity: A Rare Phenomenon

“…The mesiodens is a supernumerary tooth that derives its name from its location between the maxillary central incisors. In the literature, the prevalence of the mesiodens was reported to be between 0.15 and 1.9% [1]. They account for 80% of all supernumerary teeth and are approximately twice as frequent in men as in women and, most frequently, patients present a single supernumerary tooth [2,3].…”