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
The first deciduous teeth to erupt into the mouth appear at approximately 6 months after birth and, by around the age of 3 years, all the deciduous teeth have erupted. By 6 years of age, the first permanent teeth appear (lower incisors and first molars) and thence the deciduous teeth are exfoliated one by one as they are replaced by their permanent successors. A complete permanent dentition is present when the third molars erupt at around the age of 18–21 years. Information on the sequence of development and eruption of teeth into the oral cavity may be important in forensic medicine and archaeology in helping to age individuals. The data provided in Tables 41.3 and 41.4 concerning the chronology of tooth development are largely based on European-derived populations and there is evidence of ethnic variation. When a permanent tooth erupts, approximately two-thirds of the root is formed and it takes approximately another 3 years for the root to be completed. For deciduous teeth, root completion is more rapid. The developmental stages of initial calcification and crown completion are less affected by environmental influences than eruption, the timing of which may be modified by several factors such as early tooth loss and severe malnutrition.
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.
Profile of intrusive luxation and healing complications in deciduous and permanent teeth – a retrospective study
Published in Acta Odontologica Scandinavica, 2018
Thais Rodrigues Campos Soares, Luciana Pereira Silva, Sabrina Loren de Almeida Salazar, Ronir Raggio Luiz, Patrícia de Andrade Risso, Lucianne Cople Maia
Despite the limitations of this study, the results presented may help the dentistry in the elaboration of the conservative treatment plan in cases of dental intrusions in deciduous teeth. Understanding that the intrusion profile is different according to the type of teeth evaluated is important in formulating prevention and care strategies for patients. The results presented here, serve as a warning to the fact that permanent teeth should be monitored within a shorter consultation period to evaluate possible sequelae that may, in the long term, lead to exodontia. For deciduous teeth, the dentist should be aware that the level and the direction of intrusion did not act as an inductor of a great number of sequelae in the traumatized tooth in a short-term period, and for this reason the intruded deciduous teeth should be followed up for longer periods, until replacement. However, as the results presented do not take into account the possible sequels in the permanent successor (in cases of deciduous intrusion), more prospective studies are necessary to evaluate the sequelae in the traumatized deciduous tooth and in the successors taking into account the clinical variables in a longer evaluation time.
Diversity of site-specific microbes of occlusal and proximal lesions in severe- early childhood caries (S-ECC)
Published in Journal of Oral Microbiology, 2022
Kausar Sadia Fakhruddin, Lakshman Perera Samaranayake, Rifat Akram Hamoudi, Hien Chi Ngo, Hiroshi Egusa
This phenomenon may be due to the anatomical and structural differences of the occlusal and proximal surfaces of deciduous teeth and/or the intrinsic ecological differences in these two localities. For instance, the occlusal niches are constantly exposed to the ebb and flow of saliva with its arsenal of immune challenges and the masticatory forces due to the intermittent food intake accompanied by incessant tongue movements. Further, it has a much more dynamic environment than the proximal niches in between teeth, which are more sedate and well protected from such extrinsic stresses [8,41]. In addition, the sheltered proximal cavitated locales are almost unreachable to routine oral hygiene measures [8,41], although appliances such as interdental brushes may reach such regions. Thus, it is tempting to speculate that the inherent features overarching the proximal and distal caries ecosystems may be the critical reasons for the significant diversity in the microbiota of these two sites.
Failure of eruption of first permanent molar teeth: a diagnostic challenge
Published in Journal of Orthodontics, 2018
Suhaym Mubeen, Jadbinder Seehra
The period of observation was beneficial in this case as it revealed the unexpected vertical development of the unerupted tooth. The reason for the reversal in the eruptive potential of this tooth is unknown; however, ankylosis may be a reversible process (Andreasen & Kristerson 1981). Transient ankylosis may have prevented initial eruption of the UR6. The tooth may have proceeded to erupt if the UR7 had not mesially tipped in the intervening development period. However, the ability to regain eruptive potential following signs of failure of eruption is rare (Mistry et al. 2017). Alternatively, the first molar may have been impacted against the second deciduous molar. If the second premolar was late forming, late exfoliation of the deciduous tooth may have maintained the position of the unerupted tooth until after the second molar had erupted. Regardless of the cause, the prognosis of impacted molar teeth is relatively guarded (Valmaseda-Castellón et al. 1999). Advanced age at diagnosis, the severity of the impaction and uncertainty of conservative treatment contribute to this reduced prognosis (Valmaseda-Castellón et al. 1999).
Related Knowledge Centers
- Dental Lamina
- Embryo
- Tooth
- Polyphyodont
- Animal Tooth Development
- Tooth Eruption
- Infant
- Permanent Teeth
- Development of The Human Body
- Teething