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Growth and development
Published in Jagdish M. Gupta, John Beveridge, MCQs in Paediatrics, 2020
Jagdish M. Gupta, John Beveridge
There is great variability in dental eruption. By the age of 1 year most children will have six to eight teeth. Usually the first tooth to erupt is a lower central incisor. There are 20 deciduous teeth. The first permanent tooth to erupt is the first molar or lower central incisor; this occurs at 6-7 years of age. Calcification of the first permanent molar begins at birth in a term infant.
Experimental Stomatology
Published in Samuel Dreizen, Barnet M. Levy, Handbook of Experimental Stomatology, 2020
Samuel Dreizen, Barnet M. Levy
To clarify the role of osteoblasts and osteoclasts in vitamin A deficiency, Frandsen and Becks54 studied the effects of hypovitaminosis A on bone healing and endochondral ossification in rats. In this study, 45 male Long-Evans rats were assigned to a group of 18 started on a vitamin A-free diet at 14 days of age, a group of 18 pair-fed a control diet, and a group of 9 given the control diet ad libitum. The left lower first molar was extracted from each animal at 58 to 62 days old. Following extraction, the rats were killed at intervals ranging from 7 hr to 46 days. Heads and tibias were removed and fixed in 10% formalin, radiographed, and prepared for histologic examination.
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
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.
Evaluating tooth extraction as a stand-alone treatment for odontogenic sinusitis
Published in Acta Oto-Laryngologica, 2023
Emi Tsuchiya, Momoko Takeda, Eri Mori, Ikuko Takakura, Ryoto Mitsuyoshi, Nobuyoshi Otori, Katsuhiko Hayashi
Additionally, our results demonstrated that younger patients were less likely to be cured of OS with tooth extraction alone. The maxillary sinus begins to rapidly expand around the age of 6 years, when the first molar erupts, achieves its maximum volume between the late teens and mid-20s, and subsequently decreases with advancing age [10]. Tian et al. reported that individuals aged <40 years were more likely to have the maxillary root positioned above or inside the maxillary sinus floor [11]. Therefore, the distance between the maxillary sinus floor and the root apex of the maxillary molar is shorter in a larger maxillary sinus, leading to OS pathogenesis and intractable conditions. Moreover, it is suspected that molar tooth roots extending into the maxillary sinus are more likely to cause an inflammatory reaction in the sinus membrane because of periodontitis, which may become exacerbated with dental treatment. Leaving untreated dental lesions and improper dental treatment for the maxillary molars in young patients may lead to OS or make extant OS refractory, depending on the proximity of the roots to the maxillary sinus.
Pain, discomfort, and functional impairment after extraction of primary teeth in children with palatally displaced canines – a randomized control trial comparing extraction of the primary canine versus extraction of the primary canine and the primary first molar
Published in Acta Odontologica Scandinavica, 2023
Sigurd Hadler-Olsen, Jeanett Steinnes, Hege Nermo, Anders Sjögren, Elin Hadler-Olsen
We found that the mean level of pain and discomfort was higher in the DEG than in the SEG group at most time points assessed. There is no general agreement on the minimum clinically significant difference in VAS pain scores, but a previous study found a difference of 9 mm to be the minimum for acute pain, irrespective of age, gender, and cause of pain [24], and another study suggests that a difference of 33% is meaningful from the patients’ perspective [22]. The difference in reported pain between the SEG and the DEG exceeded 33% at all time points and was larger than 9 mm on the VAS scale during anaesthesia, extraction, and on the evening of the extraction day. Primary canines have a single, pointed root and can usually be extracted with little handling and use of force. Contrary, the primary first molar in the upper jaw has three strongly diverging roots, and usually requires more handling and use of force to be extracted. It will also leave a larger wound in the jaw after extraction than the canine. This is reflected in the children’s comments in their own words from the present study, where rotation/handling of the tooth was highlighted as especially uncomfortable by several children in the DEG. The clinical benefit of extracting both the primary canine and first molar instead of just the primary canine to enhance the eruption of PDC is controversial [10–12]. Therefore, our findings support choosing the least traumatic and best-validated procedure, namely extraction of the primary canine only.
Effect of the dimensions of implant body and thread on bone resorption and stability in trapezoidal threaded dental implants: a sensitivity analysis and optimization
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Mohammad Reza Niroomand, Masoud Arabbeiki
The tooth in the first molar segment in mandible is the first permanent tooth being encountered to the oral environment, hence, it is a common tooth being lost by dental cavities (Chidagam et al. 2017). Failure to replace a missing molar will trigger the consequence of damages to the stomatognathic system by affecting occlusion, arch form, gingival, and periodontal health of adjacent teeth eventually leading to temporomandibular joint (TMJ) issues. Therefore, the mandibular first molar is selected as a basis of solid modeling. The model is designed using ANSYS Workbench 19.1 and includes titanium threaded dental implant (ITI, Institute Straumann, Basel, Switzerland), ceramic prosthetic crown with 2 mm occlusal thickness and a cancellous bone which is covered by a layer of cortical bone (Figure 1). The type of B/2 bone is selected according to the Lekholm and Zarb classification (Lekholm 1985). The thickness of the cortical layer varies within 1.3–2.0 mm range and does not cover the distal and mesial sides.