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Crown-to-root Ratio
Crown-to-root-ratio is the ratio of the length of the part of a tooth that appears above the alveolar bone versus what lies below it. It is an important consideration in the diagnosis, treatment planning and restoration of teeth, one that hopefully guides the plan of treatment to the proper end result. Perspectives of different terminologies Anatomical terms All teeth have two general sections, the crown and the root. Because the crown is covered with enamel and the root is covered with cementum, the line at which these two sections join is called the cementoenamel junction. In health, the roots of teeth are entirely surrounded by and submerged in the alveolar bone of either the maxilla or the mandible, depending on whether the tooth in question is an upper or a lower tooth, up until the cementoenamel junction. Overlying the bone is the gingival soft tissue, which is, on average, about 1 millimeter in thickness. Because of this gingiva, the crown, which exists entirely outside ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gingival Recession
Gingival recession, also known as receding gums, is the exposure in the roots of the teeth caused by a loss of gum tissue and/or retraction of the gingival margin from the crown of the teeth.Gingival Recession - Causes and treatment JADA, Vol 138. http://jada.ada.org. Oct 2007. American Dental Association Gum recession is a common problem in adults over the age of 40, but it may also occur starting in adolescence, or around the age of 10. It may exist with or without concomitant decrease in (recession of ). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Lengthening
Crown lengthening is a surgical procedure performed by a dentist, or more frequently a specialist periodontist. There are a number of reasons for considering crown lengthening in a treatment plan. Commonly, the procedure is used to expose a greater amount of tooth structure for the purpose of subsequently restoring the tooth prosthetically. However, other indications include accessing subgingival caries, accessing perforations and to treat aesthetic disproportions such as a gummy smile. There are a number of procedures used to achieve an increase in crown length. Biomechanical considerations Biologic width Biologic width is the distance established by "the junctional epithelium and connective tissue attachment to the root surface" of a tooth. The concept was first published by Ingber JS, Rose LF and Coslet JG. - The "Biologic Width"—A Concept in Periodontics and Restorative Dentistry in 1977 in the Alpha Omegan. It was based on cadaver measurements by Gargiulo, Wentz and Or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occlusal Trauma
Occlusal trauma is the damage to teeth when an excessive force is acted upon them and they do not align properly.Bibb, CA: Occlusal Evaluation and Therapy in the Management of Periodontal Disease. In Newman, MG; Takei, HH; Carranza, FA; editors: ''Carranza’s Clinical Periodontology'', 9th Edition. Philadelphia: W.B. Saunders Company, 2002. pages 698-701. When the jaws close, for instance during chewing or at rest, the relationship between the opposing teeth is referred to as occlusion. When trauma, disease or dental treatment alters occlusion by changing the biting surface of any of the teeth, the teeth will come together differently, and their occlusion will change.Hinrichs, JE: Occlusal The Role of Dental Calculus and Other Predisposing Factors. In Newman, MG; Takei, HH; Carranza, FA; editors: ''Carranza’s Clinical Periodontology'', 9th Edition. Philadelphia: W.B. Saunders Company, 2002. page 192. When that change has a negative effect on how the teeth occlude, this may cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fulcrum (mechanics)
A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or ''fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is divided into three types. Also, leverage is mechanical advantage gained in a system. It is one of the six simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide leverage. The ratio of the output force to the input force is the mechanical advantage of the lever. As such, the lever is a mechanical advantage device, trading off force against movement. Etymology The word "lever" entered English around 1300 from Old French, in which the word was ''levier''. This sprang from the stem of the verb ''lever'', meaning "to raise". The verb, in turn, goes back to the Latin ''levare'', itself from the adjective ''levis'', meaning "light" (as in "not heavy"). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extrapolate
In mathematics, extrapolation is a type of estimation, beyond the original observation range, of the value of a variable on the basis of its relationship with another variable. It is similar to interpolation, which produces estimates between known observations, but extrapolation is subject to greater uncertainty and a higher risk of producing meaningless results. Extrapolation may also mean extension of a method, assuming similar methods will be applicable. Extrapolation may also apply to human experience to project, extend, or expand known experience into an area not known or previously experienced so as to arrive at a (usually conjectural) knowledge of the unknownExtrapolation entry at Merriam–Webster (e.g. a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiology
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical and physical functions in a living system. According to the classes of organisms, the field can be divided into medical physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysical and biochemical processes, homeostatic control mechanisms, and communication between cells. ''Physiological state'' is the condition of normal function. In contrast, ''pathological state'' refers to abnormal conditions, including human diseases. The Nobel Prize in Physiology or Medicine is awarded by the Royal Swedish Academy of Sciences for exceptional scientific achievements in physiology related to the field of medicine. Foundations Cells Although there are differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mand Right Premolar PA
Mand may refer to: __NOTOC__ Places * Mánd, a village in Szabolcs-Szatmár-Bereg county, Hungary * Mand (village), a village in Madhya Pradesh, India * Mand, Iran (other), two villages in Iran * Mand (Kech District), a town in Balochistan, Pakistan * Mand, West Virginia, United, States an unincorporated community *Mand River, a river in India People with the surname *Andreas Mand (born 1959), German writer * Mänd, an Estonian surname Other uses *Mand (psychology), B. F. Skinner's term for a verbal operant *Mand (singing style), a style of folk music in Rajasthan, India See also * * Manda (other) * Mande (other) Mande may refer to: * Mandé peoples of western Africa * Mande languages * Manding, a term covering a subgroup of Mande peoples, and sometimes used for one of them, Mandinka * Garo people of northeastern India and northern Bangladesh * Mande River ... * Mando (other) * Mandy (other) {{disambig, geo, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prognosis
Prognosis (Greek: πρόγνωσις "fore-knowing, foreseeing") is a medical term for predicting the likely or expected development of a disease, including whether the signs and symptoms will improve or worsen (and how quickly) or remain stable over time; expectations of quality of life, such as the ability to carry out daily activities; the potential for complications and associated health issues; and the likelihood of survival (including life expectancy). A prognosis is made on the basis of the normal course of the diagnosed disease, the individual's physical and mental condition, the available treatments, and additional factors. A complete prognosis includes the expected duration, function, and description of the course of the disease, such as progressive decline, intermittent crisis, or sudden, unpredictable crisis. When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periodontal Disease
Periodontal disease, also known as gum disease, is a set of inflammatory conditions affecting the tissues surrounding the teeth. In its early stage, called gingivitis, the gums become swollen and red and may bleed. It is considered the main cause of tooth loss for adults worldwide.V. Baelum and R. Lopez, “Periodontal epidemiology: towards social science or molecular biology?,”Community Dentistry and Oral Epidemiology, vol. 32, no. 4, pp. 239–249, 2004.Nicchio I, Cirelli T, Nepomuceno R, et al. Polymorphisms in Genes of Lipid Metabolism Are Associated with Type 2 Diabetes Mellitus and Periodontitis, as Comorbidities, and with the Subjects' Periodontal, Glycemic, and Lipid Profiles Journal of Diabetes Research. 2021 Jan;2021. PMCID: PMC8601849. In its more serious form, called periodontitis, the gums can pull away from the tooth, bone can be lost, and the teeth may loosen or fall out. Bad breath may also occur. Periodontal disease is generally due to bacteria in the mouth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
