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Introduction to Oral and Craniofacial Tissue Engineering
Published in Vincenzo Guarino, Marco Antonio Alvarez-Pérez, Current Advances in Oral and Craniofacial Tissue Engineering, 2020
María Verónica Cuevas González, Eduardo Villarreal-Ramírez, Adriana Pérez-Soria, Pedro Alberto López Reynoso, Vincenzo Guarino, Marco Antonio Alvarez-Pérez
Root Cementum (RC) is a mineralized tissue that surrounds the superficial root of the tooth; their function is to support the tooth through the PDL and alveolar bone (Yamamoto et al. 2016). Alveolar Bone (AB) is another mineralized tissue and is associated with the formation of membranous bone of both mandibular and maxillary tissues during the development of the first dentition, two components form this kind of bone, the first belong to the alveolar process, which in turn is composed by the cortical and cancellous bone tissue, the last one stores Haversian systems required for maintenance and remodeling of the bone; the second component is the alveolar bone itself which corresponds to the bone portion that covers the dental surface and serves as a union site to the Sharpey fibers from PDL (Chu et al. 2014). Periodontal ligament (PDL) is formed by collagen fibers which could be classified according to their localization of the fibers onto the alveolar crest, oblique, transseptal, horizontal, inter-radicular or apical (Maheaswari et al. 2015). The union of these fibers to the soft tissue provides a natural coupling of the roots of the tooth in the alveolus: the union of the PDL to the RC or the AB facilitates the transfer of loads of the teeth towards the bone, because the bone-cement/PDL-binding sites contain areas between 10–15 μm rich in biochemical gradients, which are known as enthesis sites that facilitate cell-cell interactions and communications (Lee et al. 2015).
The Digestive (Gastrointestinal) System and Its Disorders
Published in Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss, Understanding Medical Terms, 2020
Walter F. Stanaszek, Mary J. Stanaszek, Robert J. Holt, Steven Strauss
The periodontium consists of the tissues that surround and support the teeth, which are the gingiva, periodontal ligament, cementum, and alveolar bone. The gingiva is the part of the oral mucosa that covers the alveolar process of the jaw and surrounds the neck of the tooth. Periodontal ligaments serve to attach teeth to the bone; to maintain gingival tissues in the proper relationship to teeth, as shock absorbers; and to provide a casing to protect the vessels and nerves. Cementum is the calcified or hardened tissue that forms the outer covering of the anatomic root. The process of its formation is variable, but continuous. The alveolar bone or tooth socket is the socket in the maxilla (upper jawbone) or mandible (lower jawbone) into which each tooth fits.
Experimental Stomatology
Published in Samuel Dreizen, Barnet M. Levy, Handbook of Experimental Stomatology, 2020
Samuel Dreizen, Barnet M. Levy
Radiographically, there was a thinning of the cortical bone with marked lamellation, cortical microfractures, coarse and uneven trabecular networks, and widening of medullary canals. In each skull there was a partial to complete loss of lamina dura and greatly increased patchy radiolucencies in the mandible, maxilla, and calvarium. Histologically, the alveolar bone changes were denoted by a narrowing and disruption of the cortical and cribriform plates and by the presence of broad bands of osteoid around the remaining compact and spongy bone elements.
Evaluation of biomechanics using different traction devices in distalization of maxillary molar with clear aligners: a finite element study
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Construction of finite element model: 3D finite element models of the whole maxillary dentition with periodontal ligaments (PDLs) and alveolar bone were built using GEOMAGIC studio (Raindrop Geomagic, North Carolina, USA). Teeth and maxillary bone were reconstructed based on cone-beam CT (KAVO, German) scanning of an adult female subject with normal occlusion (Figure 1A). In order to establish the natural anatomy, PDLs were constructed as a linear elastic film with an average thickness of 0.25 mm around the roots of all the teeth (Figure 1B). In the next step, the alveolar bone was generated to fit the teeth and PDLs, and the alveolar bone design was under the cemento-enamel junction relation. The aligners had a thickness of 0.75 mm, in which external offset devices for all crowns and attachments were developed in the simulation (Comba et al. 2017). Canine, first and second premolars were designed with vertical rectangular attachments (Figure 2). The micro-implant (DENTOS, Korea) was positioned between the second premolar and the first molar at an angle of 45° with the occlusal plane. At the height of 4 mm and 6 mm from the alveolar crest respectively, the force of 150 g was applied to the spring that was attached to the traction device and the micro-implant (Figure 1D–F). All components were imported for FE analysis by ANSYS Workbench 15.0 (Ansys, Pennsylvania, USA).
Development and verification of a constitutive model for human periodontal ligament based on finite element analysis
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Jianlei Wu, Yunfeng Liu, Boxiu Li, Xingtao Dong
In FEA simulations, the alveolar bone model was determined as a nonuniform material with varied mechanical properties via our previous method (Wu et al. 2019, 2021), rather than being unitedly assigned as a uniform model. This was mainly because the bone element properties in various regions are discrepant in the real alveolar bone (Bujtár et al. 2010; Liu et al. 2017). In general, the alveolar bone can be artificially divided into the cortical bone and cancellous bone; the cortical bone is located in the surface layer of the alveolar bone at a high density, whereas the cancellous bone is located within the alveolar bone at a low density. However, significant differences can still be found in the alveolar bone (such as a small marrow cavity or neural cavity in cancellous bone, which has a property different than that of the bone tissue). As per our recent research (Wu, Liu, et al. 2021), the biomechanical responses of PDL were dependently influenced by the properties of the alveolar bone and the nonuniform bone model was more conducive to obtain accurate analysis results. Hence, the nonuniform alveolar bone model was employed in the present study, which can better reflect the characteristics of the real bone. Figure 3(C) and (D) shows the nonuniform alveolar bone model; the maximal Young’s modulus of the bone element was approximately 15,446 MPa, and the value conformed to the mechanical property of the cortical bone of 17,000 MPa (Benaissa et al. 2020), which demonstrated the validity of our construction method for the nonuniform alveolar bone model.
Gingival bleeding and pocket depth among smokers and the related changes after short-term smoking cessation
Published in Acta Odontologica Scandinavica, 2022
Swati Mittal, Maki Komiyama, Yuka Ozaki, Hajime Yamakage, Noriko Satoh-Asahara, Akihiro Yasoda, Hiromichi Wada, Masafumi Funamoto, Kana Shimizu, Yusuke Miyazaki, Yasufumi Katanasaka, Yoichi Sunagawa, Tatsuya Morimoto, Yuko Takahashi, Takeo Nakayama, Koji Hasegawa
Tobacco smoking is a preventable risk factor for various diseases in the human body, such as different types of cancers, respiratory tract infections, cardiac issues, and liver problems. Smoking is also associated with the health of the oral cavity and causes gingivitis, periodontitis, oral cancers, and many other problems [1]. The periodontal ligament and the supporting alveolar bone, which holds the teeth, are damaged by the inflammation caused by smoking, which ultimately leads to tooth loss. Based on observational studies included in a systemic review by Leite et al. [2], smokers have an 80% higher risk of periodontitis than quitters and never-smokers. Smoking also detrimentally affects neutrophils and macrophages, which are essential as immunocompetent gingival cells. Many studies assert that smokers have less gingival bleeding on probing than do non-smokers [3,4]. Preber et al. [4] proposed that a possible explanation for decreased gingival bleeding in smokers is vasoconstriction of the peripheral blood vessels caused by nicotine. However, heavy smokers have a severe periodontal breakdown and bleeding compared to infrequent smokers and non-smokers [5]. Thus, smoking has chronic and time-dependent effects on gingival health.