Anatomy and Embryology of the Mouth and Dentition
John C Watkinson, Raymond W Clarke, Terry M Jones, Vinidh Paleri, Nicholas White, Tim Woolford in Head & Neck Surgery Plastic Surgery, 2018
There are two generations of teeth: the deciduous (primary) dentition and the permanent (secondary) dentition. In the complete deciduous dentition there are 20 teeth—five in each jaw quadrant. In the complete permanent dentition there are 32 teeth—eight in each jaw quadrant. In both dentitions, there are three basic tooth forms: incisiform, caniniform and molariform. Incisiform teeth (incisors) are cutting teeth, having thin, blade-like crowns. Caniniform teeth (canines) are piercing or tearing teeth, having a single, stout, pointed, cone-shaped crown. Molariform teeth (molars and premolars) are grinding teeth possessing a number of cusps separated by fissures. Premolars are bicuspid teeth that are peculiar to the permanent dentition and replace the deciduous molars.
Growth and development
Jagdish M. Gupta, John Beveridge in MCQs in Paediatrics, 2020
1.44. Which of the following statements concerning teething is/are correct?A 1-year-old infant is likely to have six to eight deciduous teeth.The first deciduous tooth to erupt is an upper central incisor.There are 20 deciduous teeth.One of the first permanent teeth to erupt is a lower central incisor.Calcification of the first permanent molars begins at birth in a full-term infant.
The gastrointestinal system
C. Simon Herrington in Muir's Textbook of Pathology, 2020
The teeth consist of three specialized mineralized tissues with underlying soft-tissue pulp (Figure 10.1). Dentine is a thick layer of tubular, calcified, collagenous tissue that surrounds the pulp. On the crown of the tooth, the dentine is covered by enamel, an acellular tissue consisting largely of calcium apatite crystals in a delicate organic matrix. Cementum overlies the root dentine. At the apex of each root is one or more foramina through which vessels and nerves enter the pulp. The teeth are attached to the jaws by the periodontium, a specialized supportive complex comprising cementum, the periodontal ligament, alveolar bone, and gingiva. The deciduous or ‘baby’ teeth erupt within the first few years of life and total 20 in number. From 6 years of age, additional permanent teeth erupt and the deciduous teeth are gradually replaced by permanent successors to give a full adult complement of 32 teeth by the late teens.
Morphological variations and prevalence of aberrant traits of primary molars
Published in Annals of Human Biology, 2021
P. Sujitha, R. Bhavyaa, M. S Muthu, M. Kirthiga
The parastyle is a paramolar cusp of Bolk that occurs on the mesiobuccal surface of upper molars (Turner et al. 1991). Although the literature pertaining to this trait is negligible, it is said to be predominant in deciduous molars (Kustaloglu 1962). In the present study, the results yielded a prevalence rate of 0.51% in primary maxillary second molars and 3.48% in primary maxillary first molars. Studies conducted among southwestern and northwestern Indians (Kustaloglu 1962) gave a prevalence of 5.2% and 4.7%, respectively, in primary maxillary second molars. The prevalence found in the present study was comparatively less in primary maxillary second molars. However, the prevalence of the parastyle was higher in primary maxillary first molars. The literature suggests primary maxillary first molars to be the “premolar section” of the primary dentition and to resemble certain features of premolars (Nelson and Ash 2012). The literature also suggests that this trait occurs more in premolars (Kustaloglu 1962), which can be the reason for its higher prevalence in primary maxillary first molars.
Malocclusions in primary and early mixed dentition in very preterm children
Published in Acta Odontologica Scandinavica, 2020
Elina Maaniitty, Tero Vahlberg, Petra Lüthje, Päivi Rautava, Anna-Liisa Svedström-Oristo
All data had been gathered and saved in electronic records as part of the normal daily practice of public health centres. One examiner collected and coded the data from the electronic dental records. In cases of deviating occlusal traits or malocclusions, the status was complemented with an orthodontic examination and/or free text message (concerning, e.g. delayed tooth eruption), and with radiographs, as needed. Data included information on the child’s gender, oral habits (non-nutritive sucking), overjet, overbite, dental and jaw relations, available space in dental arches, and orthodontic treatment history. Oral habits had been recorded in a structured way from six months to three years of age; thereafter, the situation was updated, if the habit persisted at three years or if there was any reason to suspect such a habit. Included data covered developmental stages from primary dentition to the completion of early mixed dentition. Data considering dental and occlusal relationships were always collected before any orthodontic treatment. All children having orthodontic treatment in primary dentition and their age and gender-matched pairs were excluded from the analyses in the early mixed dentition stage.
Nance–Horan syndrome in females due to a balanced X;1 translocation that disrupts the NHS gene: Familial case report and review of the literature
Published in Ophthalmic Genetics, 2018
Laura Gómez-Laguna, Alejandro Martínez-Herrera, Alejandra del Pilar Reyes-de la Rosa, Constanza García-Delgado, Karem Nieto-Martínez, Fernando Fernández-Ramírez, Tania Yanet Valderrama-Atayupanqui, Ariadna Berenice Morales-Jiménez, Judith Villa-Morales, Susana Kofman, Alicia Cervantes, Verónica Fabiola Morán-Barroso
The phenotypes of the patients in this report resemble those of affected NHS males, in particular their facial characteristics and cataracts, contrasting with the subtle facial appearance and posterior Y-suture centered lens opacities generally described in NHS female carriers (Table 1). Variable degrees of intellectual disability have been identified in up to 30% of the NHS male patients. In the case of our female patients, they do not present intellectual disability, but manifest a characteristic NHS phenotype. The teeth abnormalities in NHS may be present in both primary and permanent dentition(6). Conical teeth were described in each of our patients, however it should be taken into consideration that patient 1 is four years old and still has her primary dentition. The mother received dental treatment that modified this characteristic (Figure 1).
Related Knowledge Centers
- Dental Lamina
- Embryo
- Tooth
- Polyphyodont
- Animal Tooth Development
- Tooth Eruption
- Infant
- Permanent Teeth
- Development of The Human Body
- Teething