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 teeth of the upper jaw have special relevance to ENT surgeons because of their potential close relationship to the maxillary air sinus. The root apices of the maxillary cheek teeth are close to and may even invaginate the maxillary sinus. The permanent tooth most commonly involved is the second molar, followed by the first molar. However, the premolars may also be involved as might the third molar. Following tooth extraction, resorption of alveolar bone and cavitation of the maxillary sinus may significantly increase. During removal of fractured root apices in this region, care must be taken to ensure the root fragment is not pushed into the sinus. Similarly, during root canal treatment, care must be taken not to push any filling material into the maxillary sinus. Routine X-rays may no longer be considered satisfactory in providing sufficient definition of the close relationship between the floor of the maxillary sinus and root apices and cone beam computed tomography may be necessary to provide extra detail (Figure 41.16). Due to the close anatomical relationship of the openings of the various air sinuses in the region of the middle meatus, infection of the maxillary sinus may spread to involve other sinuses and vice versa.
Head, neck and vertebral column
David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings in McMinn’s Concise Human Anatomy, 2017
Normal adult dentition consists of 32 teeth, 16 upper and 16 lower, eight in each half of each jaw, numbered and named from the midline laterally (listed here with approximate date of eruption in years): 1, central incisor (7 yr); 2, lateral incisor (8 yr); 3, canine (11 yr); 4, first premolar (9 yr); 5, second premolar (10 yr); 6, first molar (6 yr); 7, second molar (12 yr); and 8, third molar (18 yr or in later years of maturity, hence often called the ‘wisdom tooth'). The deciduous dentition of the child (‘milk teeth') consists of 20 teeth, five in each half jaw, lettered and named from the midline laterally (listed here with approximate date of eruption in months): A, central incisor (6 m); B, lateral incisor (8 m); C, canine (18 m), D, first molar (12 m); and E, second molar (24 m). Note that the deciduous molars are replaced by the permanent premolars, since the permanent molars have no precursors in the deciduous dentition.
Growning Up in Ancient America
Debra L. Martin, Anna J. Osterholtz in Bodies and Lives in Ancient America, 2015
For these reasons, this chapter focuses on early childhood (ages 2–6), late childhood (6–10), and adolescence (10–18) following the suggested age categories of Roksandic and Armstrong (2011: 341). These stages are based on distinct biological events having to do with dental and skeletal markers of development. Early childhood begins around the time that the deciduous dentition is full erupted at 2 years and ends with the emergence of the first permanent teeth, typically the first molar or central incisors at around 10 years of age. Late childhood begins with the eruption of the first permanent teeth through to the eruption of the permanent canine, typically around 10 years of age. Adolescence begins with this eruption and ends with the epiphyseal union of the long bones, typically in the late teens (see various methodologies presented in Buikstra and Ubelaker 1994). Using these three distinct age categories to think about growing up in ancient America takes advantage of the timing of weaning at around 2 (which can place infants and children at risk for disease) and the timing of the fully matured immune system at around 6 (which protects children from some diseases).
Reliability of radiographic findings in large FOV CBCTs of mandibular third molars as basis for pre-operative patient information
Published in Acta Odontologica Scandinavica, 2022
Louise Hauge Matzen, Lars Schropp, Louise Hermann, Janne Ingerslev, Ann Wenzel
Two hundred and nine mandibular third molars (104 left side and 105 right side) in 55 male and 79 female patients (mean age at the day of third molar removal 22 years, range 18–52) were included in this study. The patients were mostly consecutively referred from an orthodontist in private practice or community health care clinics for orthognathic surgery at the Department of Oral and Maxillofacial Surgery, University Hospital of Southern Denmark, Esbjerg, Denmark during a 2-year period from 2015–2017. At the hospital, the patients underwent a clinical and radiographic examination including a panoramic and a CBCT examination to plan the orthodontic pre-treatment as well as the orthognathic surgery. In the department, the majority of third molars were consequently removed before the orthodontic pre-treatment and the orthognathic surgery to obtain optimal bone conditions in relation to the healing process after the SSO. The third molars were removed with a maximum of three months (average two months and 12 days) after the CBCT examination was performed. After removal of the third molar(s), the patients started the orthodontic pre-treatment, and approximately 1.5 years after removal of the third molar(s) and the pre-surgical orthodontic treatment, the orthognathic surgery was performed. This study includes data regarding mandibular third molar removal from patients undergoing subsequent orthognathic surgery. The study does not include data or information from either the orthodontic pre-treatment or the orthognathic surgery.
Risk factors for root resorption of second molars with impacted third molars: a meta-analysis of CBCT studies
Published in Acta Odontologica Scandinavica, 2023
Yuecui Ma, Daogui Mu, Xiangxin Li
The position of contact was also strongly linked to the inclination of the teeth. Our findings show that M2 in close proximity to mesio-angular impacted M3 had 50% higher risk of ERR than with vertical, traverse or horizontally impacted M3. Additionally, the prevalence of ERR seems to be higher with transverse, horizontal and mesio-angular impacted M3, with 54.5%, 47.5% and 44.5% of occurrence, respectively. These results are in agreement with the results of Oenning et al. 2015 who reported the incidence of ERR in adjacent second molars in relation to horizontal and mesio-angular impacted mandibular third molars [3]. They observed that mesially inclined third molars (mesio-angular and horizontal) are more likely to be linked to second molar ERR. Furthermore, mesio-angularly inclined M3 are more likely to come into direct contact with M2, which may explain higher incidence of ERR in these patients.
Elevating the use of sugar-free chewing gum in Germany: cost saving and caries prevention
Published in Acta Odontologica Scandinavica, 2018
Stefan Zimmer, Anna Spyra, Fabian Kreimendahl, Cornelia Blaich, Reinhard Rychlik
By applying these conditions, the transitional probabilities can be solved using MS Excel Solver. As a next step, separate distributions for both one molar and one anterior tooth need to be defined so that the combination of both distributions equals the overall model. Since the human permanent dentition consists of 16 posterior teeth (without third molars) and 12 anterior teeth, relative weights of 16/28 for posterior and 12/28 for anterior teeth for each distribution are the result. On the basis of clinical experience, one out of the six remaining teeth at the age of 74 is a molar and five are anterior teeth. Transitional probabilities for posterior and anterior teeth can be calculated separately, on the basis of the described considerations so that the combined and weighted distribution of probabilities corresponds to the overall model. Transitional probabilities from one tooth state to another may vary depending on age of teeth or other parameters.
Related Knowledge Centers
- Cingulum
- Maxillary First Molar
- Maxillary Second Molar
- Mouth
- Tooth
- Chewing
- Cusp
- Wisdom Tooth
- Mandibular First Molar
- Mandibular Second Molar