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Anatomy and Embryology of the Mouth and Dentition
Published in John C Watkinson, Raymond W Clarke, Terry M Jones, Vinidh Paleri, Nicholas White, Tim Woolford, 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.
Maxillofacial Trauma
Published in Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie, Bailey & Love's Short Practice of Surgery, 2018
Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie
The primary (deciduous) dentition is usually fully erupted by 2.5 years, and the first permanent teeth (lower incisors) usually erupt at about the age of 6. Between the ages of 5 and 13 the primary dentition is shed and replaced by the secondary teeth.
Alveolar bone grafting in cleft patients
Published in John Dudley Langdon, Mohan Francis Patel, Robert Andrew Ord, Peter Brennan, Operative Oral and Maxillofacial Surgery, 2017
Historically, several surgeons have carried out ‘primary’ alveolar cleft bone grafting sometimes using autogenous rib as the donor material. Timing has varied between 6 months of age, at the same time as lip and palate repair up to 3–4 years but always in the time of the ‘primary’ dentition. The literature demonstrates good initial results but with later concerns. Mainly, these relate to the impact on maxillary growth but also that the alveolar bone later often becomes deficient, too deficient to allow normal eruption and orthodontics of the permanent dentition and therefore further bone grafting is required.
Maturation of the oral microbiota during primary teeth eruption: a longitudinal, preliminary study
Published in Journal of Oral Microbiology, 2022
He Xu, Bijun Tian, Weihua Shi, Jing Tian, Wenjun Wang, Man Qin
Within-group calculation showed increasing trends of microbiota diversity in both saliva and plaque. Increase in the salivary microbial diversity was detected from S1 to S4 (P < 0.05), although a short decreasing trend was detected in salivary microbial richness from S1 to S3 (no significance), which may be related to the short existence and abundance decreasing of the transient bacteria. In the meantime, the microbial diversity in plaque increased steadily (Figure 4). Permanova tests showed significant variations in β diversity from S1 to S3-S5 in saliva and from S2 to S3-S5 in plaque (P < 0.05, Appendix Table 5). No significant variation was found after S3 in both groups. These results indicate that by the state of all the eight primary incisors erupt, the microbiota structure of both saliva and supragingival plaque has been preliminarily established and will persist until the completion of primary dentition.
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.
Early childhood caries risk assessment in 1-year-olds evaluated at 6-years of age
Published in Acta Odontologica Scandinavica, 2021
Ann Ingemansson Hultquist, Lars Brudin, Mats Bågesund
A total of 804 children (410 boys, 394 girls) (79% of the 1013 children examined at baseline) were assessed at the ages of 1, 3 and 6 years. A dental hygienist or dental assistant assessed 39 (4.9%) of the 1-year-olds to be at risk of developing dental caries during the coming years. MS was present in 250 (31%) of the 1-year-olds. At 3 years of age, a dentist or dental hygienist assessed 100 (12.4%) of the children to be at risk for developing caries. None of the one-year-olds were diagnosed with dental caries. The distribution of dentine caries (deft) at 3 and 6 years of age is shown in Table 1. At the age of 3, 25 (3.1%) of the children (18 boys, seven girls) were diagnosed with dentine caries lesions. At the age of 6, 127 (16%) of the children (75 boys, 52 girls) were diagnosed with dentine caries (deft > 0) in the primary dentition. The mean ± SD caries prevalence (deft) at 3 years was 0.10 ± 0.73. The mean ± SD caries prevalence (deft) at 6 years was 0.48 ± 1.50.