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Maxillary Second Premolar
The maxillary second premolar is one of two teeth located in the upper maxilar, laterally (away from the midline of the face) from both the maxillary first premolars of the mouth but mesial (toward the midline of the face) from both maxillary first molars. The function of this premolar is similar to that of first molars in regard to grinding being the principal action during mastication, commonly known as chewing. There are two cusps on maxillary second premolars, but both of them are less sharp than those of the maxillary first premolars. There are no deciduous (baby) maxillary premolars. Instead, the teeth that precede the permanent maxillary premolars are the deciduous maxillary molars. In the universal system of notation, the permanent maxillary premolars are designated by a number. The right permanent maxillary second premolar is known as "4", and the left one is known as "13". In the Palmer notation Palmer notation (sometimes called the "Military System" and named f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deciduous Teeth
Deciduous teeth or primary teeth, also informally known as baby teeth, milk teeth, or temporary teeth,Fehrenbach, MJ and Popowics, T. (2026). ''Illustrated Dental Embryology, Histology, and Anatomy'', 6th edition, Elsevier, page 287–296. are the first set of teeth in the growth and development of humans and other diphyodonts, which include most mammals but not elephants, kangaroos, or manatees, which are polyphyodonts. Deciduous teeth Animal tooth development, develop during the embryonic stage of development and tooth eruption, erupt (break through the gums and become visible in the mouth) during infancy. They are usually lost and replaced by permanent teeth, but in the absence of their permanent replacements, they can remain functional for many years into adulthood. Development Formation Primary teeth start to form during the embryonic phase of human development (biology), human life. The development of primary teeth starts at the sixth week of tooth development as the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth (human)
A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the outermost embryonic germ layer, the ectoderm. The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartilaginous fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Face
The face is the front of the head that features the eyes, nose and mouth, and through which animals express many of their emotions. The face is crucial for human identity, and damage such as scarring or developmental deformities may affect the psyche adversely. Structure The front of the human head is called the face. It includes several distinct areas, of which the main features are: *The forehead, comprising the skin beneath the hairline, bordered laterally by the temples and inferiorly by eyebrows and ears *The eyes, sitting in the orbit and protected by eyelids and eyelashes * The distinctive human nose shape, nostrils, and nasal septum *The cheeks, covering the maxilla and mandible (or jaw), the extremity of which is the chin *The mouth, with the upper lip divided by the philtrum, sometimes revealing the teeth Facial appearance is vital for human recognition and communication. Facial muscles in humans allow expression of emotions. The face is itself a highly s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxillary First Premolar
The maxillary first premolar is one of two premolars that exist in the maxilla. Premolars are only found in the adult dentition and typically erupt at the age of 10–11, replacing the first molars in primary dentition. The maxillary first premolar is located behind the canine and in front of the second premolar. Its function is to bite and chew food. Notation For Palmer notation, the right maxillary premolar is known as “4⏌” and the left maxillary premolar is known as “⎿4”. For FDI notation, the right maxillary premolar is known as “14” and the left maxillary premolar is known as “24”. Tooth morphology The maxillary first premolar has two well-defined cusps, a buccal cusp and a lingual cusp, with the buccal cusp often 1mm taller than the lingual cusp, giving the tooth an angular crown. This crown is broader buccolingually than mesiodistally, resulting in a characteristic hexagonal or six-sided shape when viewed from the occlusal aspect. It is typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mouth
A mouth also referred to as the oral is the body orifice through which many animals ingest food and animal communication#Auditory, vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also the first part of the alimentary canal, which leads to the pharynx and the gullet. In tetrapod vertebrates, the mouth is bounded on the outside by the lips and cheeks — thus the oral cavity is also known as the buccal cavity (from Latin ', meaning "cheek") — and contains the tongue on the inside. Except for some groups like birds and lissamphibians, vertebrates usually have teeth in their mouths, although some fish species have pharyngeal teeth instead of oral teeth. Most bilaterian phylum, phyla, including arthropods, molluscs and chordates, have a two-opening gut tube with a mouth at one end and an anus at the other. Which end forms first in ontogeny is a criterion used to classify bilaterian animals into protostomes and deuterostomes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxillary First Molar
The maxillary first molar is the human tooth located laterally (away from the midline of the face) from both the maxillary second premolars of the mouth but mesial (toward the midline of the face) from both maxillary second molars. The function of this molar is similar to that of all molars in regard to grinding being the principal action during mastication, commonly known as chewing. There are usually four cusps on maxillary molars, two on the buccal (side nearest the cheek) and two palatal (side nearest the palate). There may also be a fifth smaller cusp on the palatal side known as the Cusp of Carabelli. Normally, maxillary molars have four lobes, two buccal and two lingual, which are named in the same manner as the cusps that represent them ( mesiobuccal, distobuccal, mesiolingual, and distolingual lobes). Unlike the anterior teeth and premolars, molars do not exhibit facial developmental depressions. Evidence of lobe separation can be found in the central groove, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premolar
The premolars, also called premolar Tooth (human), teeth, or bicuspids, are transitional teeth located between the Canine tooth, canine and Molar (tooth), molar teeth. In humans, there are two premolars per dental terminology#Quadrant, quadrant in the permanent teeth, permanent set of teeth, making eight premolars total in the mouth. They have at least two Cusp (dentistry), cusps. Premolars can be considered transitional teeth during chewing, or mastication. They have properties of both the canines, that lie anterior and molars that lie Posterior (anatomy), posterior, and so food can be transferred from the canines to the premolars and finally to the molars for grinding, instead of directly from the canines to the molars. Human anatomy The premolars in humans are the maxillary first premolar, maxillary second premolar, mandibular first premolar, and the mandibular second premolar. Premolar teeth by definition are permanent teeth Anatomical terms of location#Proximal and distal, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mastication
Chewing or mastication is the process by which food is comminution, crushed and ground by the teeth. It is the first step in the process of digestion, allowing a greater surface area for digestive enzymes to break down the foods. During the mastication process, the food is positioned by the cheek and tongue between the teeth for grinding. The muscles of mastication move the jaws to bring the teeth into intermittent contact, repeatedly occlusion (dentistry), occluding and opening. As chewing continues, the food is made softer and warmer, and the enzymes in saliva begin to break down carbohydrates in the food. After chewing, the food (now called a Bolus (digestion), bolus) is swallowed. It enters the esophagus and via peristalsis continues on to the stomach, where the next step of digestion occurs. Increasing the number of chews per bite stimulates the production of digestive enzymes and peptides and has been shown to increase diet-induced thermogenesis (DIT) by activating the sympa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cusp (dentistry)
A cusp is a pointed, projecting, or elevated feature. In animals, it is usually used to refer to raised points on the crowns of teeth. The concept is also used with regard to the leaflets of the four heart valves. The mitral valve, which has two Heart valve#Structure, cusps, is also known as the bicuspid valve, and the tricuspid valve has three cusps. In humans A cusp is an Commonly used terms of relationship and comparison in dentistry, occlusal or Commonly used terms of relationship and comparison in dentistry, incisal eminence on a tooth. canine tooth, Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps. In certain populations the maxillary molars, especially first molars, will possess a fifth cusp situated on the Commonly used terms of relationship and comparison in dentistry, mesiolingual cusp known as the Cusp of Carabelli. One other variat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deciduous Teeth
Deciduous teeth or primary teeth, also informally known as baby teeth, milk teeth, or temporary teeth,Fehrenbach, MJ and Popowics, T. (2026). ''Illustrated Dental Embryology, Histology, and Anatomy'', 6th edition, Elsevier, page 287–296. are the first set of teeth in the growth and development of humans and other diphyodonts, which include most mammals but not elephants, kangaroos, or manatees, which are polyphyodonts. Deciduous teeth Animal tooth development, develop during the embryonic stage of development and tooth eruption, erupt (break through the gums and become visible in the mouth) during infancy. They are usually lost and replaced by permanent teeth, but in the absence of their permanent replacements, they can remain functional for many years into adulthood. Development Formation Primary teeth start to form during the embryonic phase of human development (biology), human life. The development of primary teeth starts at the sixth week of tooth development as the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permanent Teeth
Permanent teeth or adult teeth are the second set of teeth formed in diphyodont mammals. In humans and old world simians, there are thirty-two permanent teeth, consisting of six maxillary and six mandibular molars, four maxillary and four mandibular premolars, two maxillary and two mandibular canines, four maxillary and four mandibular incisors. Timeline The first permanent tooth usually appears in the mouth at around 5-6 years of age, and the mouth will then be in a transition time with both primary (or deciduous dentition) teeth and permanent teeth during the mixed dentition period until the last primary tooth is lost or shed. The first of the permanent teeth to erupt are the permanent first molars, right behind the last 'milk' molars of the primary dentition. These first permanent molars are important for the correct development of a permanent dentition. Up to thirteen years of age, 28 of the 32 permanent teeth will appear. The full permanent dentition is completed much l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Numbering System (dental)
The Universal Numbering System, sometimes called the "American System", is a dental notation system commonly used in the United States. Most of the rest of the world uses the FDI World Dental Federation notation, accepted as an international standard by the International Standards Organization as ISO 3950. However, dentists in the United Kingdom commonly still use the older Palmer notation despite the difficulty in representing its graphical components in computerized (non-handwritten) records. Left and right Dental charts are normally arranged from the viewpoint of a dental practitioner facing a patient. The patient's right side appears on the left side of the chart, and the patient's left side appears on the right side of the chart. The labels "right" and "left" on the charts in this article correspond to the patient's right and left, respectively. Universal numbering system Although it is named the "universal numbering system", it is also called the "American system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
