A characteristic feature of mammalian dentition is the evolutionary reduction of tooth number and replacement. Because mice do not replace teeth, here we used Sorex araneus, the common shrew, as a model to investigate the loss of tooth replacement. Historically, shrews have been reported to initiate the development of several, milk or deciduous teeth but these soon become rudimentary and only t...

Dens invaginatus is a rare developmental malformation resulting from an alteration in the normal growth pattern of the dental papilla. Teeth in both maxillary and mandibular arches may be affected, but the permanent maxillary lateral incisors are the most frequently involved teeth. The invagination ranges from slight accentuation of a lingual pit to an anomaly occupying most of the crown and ro...

Supernumerary teeth and tooth agenesis are common morphological anomalies in humans. We previously obtained evidence that supernumerary maxillary incisors form as a result of the successive development of the rudimentary maxillary incisor tooth germ in Usag-1 null mice. The development of tooth germs is arrested in Runx2 null mice, and such mice also exhibit lingual epithelial buds associated w...

Developmental anomalies in the hard tissue are seen frequently in dental practice. Gemination and fusion are the most commonly encountered anomalies, and distinction between the two is always challenging. Gemination, also called double tooth, is an anomaly exhibiting two joined crowns and usually a single root. It represents an incomplete attempt of a single tooth germ to split. It is considere...

Accelerating the rate of tooth movement is desirable to patients because it shortens treatment time and also to orthodontists because treatment duration has been linked to an increased risk of gingival inflammation, decalcification, dental caries, and root resorption. Corticotomies, which some orthodontists are currently using to speed up tooth movements, induce a regional acceleratory phenomen...

Dens invaginatus results from an infolding of the outer surface of a tooth. The clinical importance of dens invaginatus results from the risk of pulpal disease. So, all clinicians should be aware of this anomaly. The presence of double dens invaginatus is extremely rare. This article presents three cases of double dens invaginatus in permanent maxillary lateral incisors, one with preventive res...

Transmission error in gearing system is a critical index for product quality. Gears with appropriate tooth modification can always behave well in transmission error, i.e. the double crowned gears. Nevertheless, to manufacture a gear with double crowning by CNC gear shaving machine indeed costly. This paper investigated the manufacture of double crowned gears by traditional gear shaving machine....

The aim of this investigation was to study children with supernumerary teeth who visited the Department of Pedodontics and Preventive Dentistry, Government Dental College and Hospital, Rohtak, Haryana, India. Only children with supernumerary teeth were included in the study while patients having supernumerary teeth with associated syndromes were excluded. Supernumeraries were detected by clinic...

trauma to primary teeth can lead to devastating sequels in development of permanent successors. the disturbance may range from enamel hypoplasia and/or hypo-calcification to arrest of dental bud development. crown dilaceration of permanent teeth is one of the consequences of trauma to deciduous teeth mainly due to intrusion or avulsion. this report presents a mandibular central incisor with dil...