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Periodontium
The periodontium is the specialized tissues that both surround and support the teeth, maintaining them in the maxillary and mandibular bones. The word comes from the Greek terms περί ''peri''-, meaning "around" and -''odont'', meaning "tooth". Literally taken, it means that which is "around the tooth". Periodontics is the dental specialty that relates specifically to the care and maintenance of these tissues. It provides the support necessary to maintain teeth in function. It consists of four principal components, namely: * Gingiva * Periodontal ligament (PDL) * Cementum * Alveolar bone proper Each of these components is distinct in location, architecture, and biochemical properties, which adapt during the life of the structure. For example, as teeth respond to forces or migrate medially, bone resorbs on the pressure side and is added on the tension side. Cementum similarly adapts to wear on the occlusal surfaces of the teeth by apical deposition. The periodontal ligament in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cementum
Cementum is a specialized calcified substance covering the root of a tooth. The cementum is the part of the periodontium that attaches the teeth to the alveolar bone by anchoring the periodontal ligament.Illustrated Dental Embryology, Histology, and Anatomy, Bath-Balogh and Fehrenbach, Elsevier, 2011, page 170. Structure The cells of cementum are the entrapped cementoblasts, the cementocytes. Each cementocyte lies in its lacuna, similar to the pattern noted in bone. These lacunae also have canaliculi or canals. Unlike those in bone, however, these canals in cementum do not contain nerves, nor do they radiate outward. Instead, the canals are oriented toward the periodontal ligament and contain cementocytic processes that exist to diffuse nutrients from the ligament because it is vascularized. After the apposition of cementum in layers, the cementoblasts that do not become entrapped in cementum line up along the cemental surface along the length of the outer covering of the perio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periodontology
Periodontology or periodontics (from Ancient Greek , – 'around'; and , – 'tooth', genitive , ) is the specialty of dentistry that studies supporting structures of teeth, as well as diseases and conditions that affect them. The supporting tissues are known as the periodontium, which includes the gingiva (gums), alveolar bone, cementum, and the periodontal ligament. A periodontist is a dentist that specializes in the prevention, diagnosis and treatment of periodontal disease and in the placement of dental implants. The periodontium The term ''periodontium'' is used to describe the group of structures that directly surround, support and protect the teeth. The periodontium is composed largely of the gingival tissue and the supporting bone. Gingivae Normal gingiva may range in color from light coral pink to heavily pigmented. The soft tissues and connective fibres that cover and protect the underlying cementum, periodontal ligament and alveolar bone are known as the ging ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periodontics
Periodontology or periodontics (from Ancient Greek , – 'around'; and , – 'tooth', genitive , ) is the specialty of dentistry that studies supporting structures of teeth, as well as diseases and conditions that affect them. The supporting tissues are known as the periodontium, which includes the gingiva (gums), alveolar bone, cementum, and the periodontal ligament. A periodontist is a dentist that specializes in the prevention, diagnosis and treatment of periodontal disease and in the placement of dental implants. The periodontium The term ''periodontium'' is used to describe the group of structures that directly surround, support and protect the teeth. The periodontium is composed largely of the gingival tissue and the supporting bone. Gingivae Normal gingiva may range in color from light coral pink to heavily pigmented. The soft tissues and connective fibres that cover and protect the underlying cementum, periodontal ligament and alveolar bone are known as the gingivae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cementum
Cementum is a specialized calcified substance covering the root of a tooth. The cementum is the part of the periodontium that attaches the teeth to the alveolar bone by anchoring the periodontal ligament.Illustrated Dental Embryology, Histology, and Anatomy, Bath-Balogh and Fehrenbach, Elsevier, 2011, page 170. Structure The cells of cementum are the entrapped cementoblasts, the cementocytes. Each cementocyte lies in its lacuna, similar to the pattern noted in bone. These lacunae also have canaliculi or canals. Unlike those in bone, however, these canals in cementum do not contain nerves, nor do they radiate outward. Instead, the canals are oriented toward the periodontal ligament and contain cementocytic processes that exist to diffuse nutrients from the ligament because it is vascularized. After the apposition of cementum in layers, the cementoblasts that do not become entrapped in cementum line up along the cemental surface along the length of the outer covering of the perio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periodontal Ligament
The periodontal ligament, commonly abbreviated as the PDL, is a group of specialized connective tissue fibers that essentially attach a tooth to the alveolar bone within which it sits. It inserts into root cementum one side and onto alveolar bone on the other. Structure The PDL consists of principal fibres, loose connective tissue, blast and clast cells, oxytalan fibres and Cell Rest of Malassez. Alveolodental ligament The main principal fiber group is the alveolodental ligament, which consists of five fiber subgroups: alveolar crest, horizontal, oblique, apical, and interradicular on multirooted teeth. Principal fibers other than the alveolodental ligament are the transseptal fibers. All these fibers help the tooth withstand the naturally substantial compressive forces that occur during chewing and remain embedded in the bone. The ends of the principal fibers that are within either cementum or alveolar bone proper are considered Sharpey fibers. * Alveolar crest fibers ('' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periodontal Fiber
The periodontal ligament, commonly abbreviated as the PDL, is a group of specialized connective tissue fibers that essentially attach a tooth to the alveolar bone within which it sits. It inserts into root cementum one side and onto alveolar bone on the other. Structure The PDL consists of principal fibres, loose connective tissue, blast and clast cells, oxytalan fibres and Cell Rest of Malassez. Alveolodental ligament The main principal fiber group is the alveolodental ligament, which consists of five fiber subgroups: alveolar crest, horizontal, oblique, apical, and interradicular on multirooted teeth. Principal fibers other than the alveolodental ligament are the transseptal fibers. All these fibers help the tooth withstand the naturally substantial compressive forces that occur during chewing and remain embedded in the bone. The ends of the principal fibers that are within either cementum or alveolar bone proper are considered Sharpey fibers. * Alveolar crest fibers ('' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gingiva
The gums or gingiva (plural: ''gingivae'') consist of the mucosal tissue that lies over the mandible and maxilla inside the mouth. Gum health and disease can have an effect on general health. Structure The gums are part of the soft tissue lining of the mouth. They surround the teeth and provide a seal around them. Unlike the soft tissue linings of the lips and cheeks, most of the gums are tightly bound to the underlying bone which helps resist the friction of food passing over them. Thus when healthy, it presents an effective barrier to the barrage of periodontal insults to deeper tissue. Healthy gums are usually coral pink in light skinned people, and may be naturally darker with melanin pigmentation. Changes in color, particularly increased redness, together with swelling and an increased tendency to bleed, suggest an inflammation that is possibly due to the accumulation of bacterial plaque. Overall, the clinical appearance of the tissue reflects the underlying histology, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alveolar Bone
The alveolar process () or alveolar bone is the thickened ridge of bone that contains the tooth sockets on the jaw bones (in humans, the maxilla and the mandible). The structures are covered by gums as part of the oral cavity. The synonymous terms ''alveolar ridge'' and ''alveolar margin'' are also sometimes used more specifically to refer to the ridges on the inside of the mouth which can be felt with the tongue, either on roof of the mouth between the upper teeth and the hard palate or on the bottom of the mouth behind the lower teeth. Terminology The term ''alveolar'' () ('hollow') refers to the cavities of the tooth sockets, known as dental alveoli. The alveolar process is also called the ''alveolar bone'' or ''alveolar ridge''. The curved portion is referred to as the alveolar arch. The alveolar bone proper, also called bundle bone, directly surrounds the teeth. The term alveolar crest describes the extreme rim of the bone nearest to the crowns of the teeth. The portion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Remodeling
Bone remodeling (or bone metabolism) is a lifelong process where mature bone tissue is removed from the skeleton (a process called ''bone resorption'') and new bone tissue is formed (a process called ''ossification'' or ''new bone formation''). These processes also control the reshaping or replacement of bone following injuries like fractures but also micro-damage, which occurs during normal activity. Remodeling responds also to functional demands of the mechanical loading. In the first year of life, almost 100% of the skeleton is replaced. In adults, remodeling proceeds at about 10% per year. An imbalance in the regulation of bone remodeling's two sub-processes, bone resorption and bone formation, results in many metabolic bone diseases, such as osteoporosis. Physiology Bone homeostasis involves multiple but coordinated cellular and molecular events. Two main types of cells are responsible for bone metabolism: osteoblasts (which secrete new bone), and osteoclasts (which brea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atrophy
Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations (which can destroy the gene to build up the organ), poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to the target organ, excessive amount of apoptosis of cells, and disuse or lack of exercise or disease intrinsic to the tissue itself. In medical practice, hormonal and nerve inputs that maintain an organ or body part are said to have ''trophic'' effects. A diminished muscular trophic condition is designated as ''atrophy''. Atrophy is reduction in size of cell, organ or tissue, after attaining its normal mature growth. In contrast, hypoplasia is the reduction in the cellular numbers of an organ, or tissue that has not attained normal maturity. Atrophy is the general physiological process of reabsorption and breakdown of tissues, involving apoptosis. When it occurs as a result of disease or loss of trophic support because of other diseases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trabecula
A trabecula (plural trabeculae, from Latin for "small beam") is a small, often microscopic, tissue element in the form of a small beam, strut or rod that supports or anchors a framework of parts within a body or organ. A trabecula generally has a mechanical function, and is usually composed of dense collagenous tissue (such as the trabecula of the spleen). It can be composed of other material such as muscle and bone. In the heart, muscles form trabeculae carneae and septomarginal trabeculae. Cancellous bone is formed from groupings of trabeculated bone tissue. In cross section, trabeculae of a cancellous bone can look like septa, but in three dimensions they are topologically distinct, with trabeculae being roughly rod or pillar-shaped and septa being sheet-like. When crossing fluid-filled spaces, trabeculae may offer the function of resisting tension (as in the penis, see for example trabeculae of corpora cavernosa and trabeculae of corpus spongiosum) or providing a cell fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoclasts
An osteoclast () is a type of bone cell that breaks down bone tissue. This function is critical in the maintenance, repair, and remodeling of bones of the vertebral skeleton. The osteoclast disassembles and digests the composite of hydrated protein and mineral at a molecular level by secreting acid and a collagenase, a process known as ''bone resorption''. This process also helps regulate the level of blood calcium. Osteoclasts are found on those surfaces of bone that are undergoing resorption. On such surfaces, the osteoclasts are seen to be located in shallow depressions called ''resorption bays (Howship's lacunae)''. The resorption bays are created by the erosive action of osteoclasts on the underlying bone. The border of the lower part of an osteoclast exhibits finger-like processes due to the presence of deep infoldings of the cell membrane; this border is called ''ruffled border''. The ruffled border lies in contact with the bone surface within a resorption bay. The peripher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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