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Overview of the Basic Anatomy of Teeth PDF Print E-mail

 There are two sets of teeth that develop in a person’s mouth during his/her lifetime. The first set is commonly called as “Milk or Baby“ teeth. These teeth already begin to develop while the baby is still a fetus. Good nutrition and diet from the mother during pregnancy is very important in the development of these teeth. The pregnant mother's diet should have adequate amounts of important vitamins and minerals such as calcium, phosphorus, vitamin C, and vitamin D. This first set of teeth are also called as the “primary teeth” and a complete set usually consists of 20 (10 upper teeth and 10 lower teeth). Primary teeth usually begin to come out (erupt) when a child’s age is between 6 months to 1 year old. Most children develop all their baby teeth at the age of 3.


The second set of teeth (adult) begins to come out at the age of 6. These teeth should be well taken cared of the rest of the person’s lifetime, since they will not get replaced anymore (at least by natural ones).There are a total of 32 permanent teeth in an adult mouth. A set of teeth is called an arch; therefore a person has two arches, an upper and a lower arch each found on the upper and lower jaws respectively. Normally, a total of 16 teeth may be found on each complete arch.

There are several types of permanent teeth.

· Incisors: The square-shaped teeth located in the front of the mouth, with four on the bottom and four on top are called incisors.

· Canines: The sharp teeth located near the corner of the mouth just located on both sides of the incisors are called canines or cuspids (pangil).

These front teeth, incisors and canines, are used to bite into and tear food. They are also very important in terms of a person’s looks and beauty (esthetics). Losing these teeth will greatly affect a person’s confidence.

· Premolars: After the canines are the premolars or bicuspids. There are a total of 8 premolars inside the mouth. 4 premolars may be found on each (upper and lower) arch. 2 on each side after each upper and lower canines. The premolar located right behind the canine is called the first premolar, and the other one next to it is the second premolar.

· Molars: Next to the premolars are the molars (Bagang) which are the biggest teeth and have the largest chewing surfaces. There are 6 molars on each arch (3 on each right and left side), therefore a total of 12 inside the mouth in both the upper and lower jaws. Molars are the last three teeth found on each side and are known as the first, second and third molars. The third molars are commonly known as the wisdom teeth. They are the last teeth to come out and located farthest inside. They usually cause complications because there is not enough space for these wisdom teeth to come out normally (Impacted). If a wisdom tooth is impacted, then the dentist may require removal of these teeth. All these molars have irregular or rugged surfaces on top consisting of grooves and pointed areas (cusps) which are designed to grind food.

Permanent teeth erupt in stages that approximately match up with the following age ranges:

  • · 6 to 7 years: first molars
  • · 6 to 9 years: incisors
  • · 9 to 12 years: canines
  • · 10 to 12 years: premolars
  • · 11 to 13 years: second molars
  • · 17 to 21 years: third molars (wisdom teeth)

Anatomy of a Tooth

Tooth Anatomy from wikipediaThe human tooth consists of two main parts: the crown and the root.

CROWN: When you look inside a person’s mouth, the visible part of the tooth above the gum is the crown. Crowns have different shapes according to the function and use of a particular tooth. The front teeth (incisors) are sharp and shaped like a chisel to be able to take a bite on food. The canines (pangil) are much sharper and pointed so that they may be very efficient in tearing food. The molars (bagang) at the back of the mouth have larger and more rugged surfaces, which make them perfect for grinding and mashing food.

The crown of a tooth consists of 3 layers:

  1. Enamel: The dental crown is covered by a hard layer of enamel. Enamel is the hardest and most solid material in the human body. As much as 95% of the enamel consists of a mineral called calcium hydroxyapatite. This layer normally gives the whitish shade or color of a tooth. When it is thin, enamel becomes translucent. It tends to show or expose the yellowish layer under it. This is the reason why some teeth are more colored yellow than others. Even though the enamel is hard, it can still be broken down (decay/caries) if the teeth are not kept clean and free of “plaque”.
  2. Dentin: Only the visible surface of a tooth is covered by enamel. The tooth primarily consists of dentin, which also consists of calcium hydroxylapatite crystals like the enamel. However, this mineral only makes up roughly 30% of the dentin making this layer much softer than the enamel layer. When dentin is exposed, the tooth becomes very sensitive since this layer contains a lot of very small tubes leading to the nerve system of the tooth.
  3. Pulp: At the center of the tooth, there is a chamber surrounded by dentin which contains the dental pulp. The pulp is commonly called the “nerve” of the tooth. But actually, the pulp does not only contain small nerves, but it consists of small systems of blood supply and lymphatic tissue as well. It is the only soft tissue in the tooth. When this area is exposed due to caries (dental decay), the tooth becomes very painful and when not treated will lead to the tooth’s death.


ROOT: The root is the part of the tooth which is not exposed or seen because it is hidden under the gum. This part usually makes up around 2/3 of the entire length of a tooth. Front teeth have only 1root, premolars have 1 or 2, and molars have 3 and sometimes 4.

  • The root consists mostly of dentin but is covered by a layer which is also mineralized like enamel and dentin but much softer. The layer is called cementum. Cementum connects to very small fibers called periodontal fibers/ligaments which are responsible for attaching the tooth to the bone of the jaw. These fibers anchor the teeth to the bone and act as shock absorbers to prevent trauma to teeth when the person chews.
  • Inside the roots are small canals where the “pulp” passes thru from the pulp chamber and connects to the main blood and nerve supply located at the tip of each root. These are called Root Canals.

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More Resources:

Dental anatomy

Adult and "Baby" teeth diagram.
Adult and "Baby" teeth diagram.

Dental anatomy or anatomy of teeth is a field of anatomy dedicated to the study human teeth structures. The development, appearance, and classification of teeth fall within its purvue, though the function of teeth as they contact one another is referred to as dental occlusion. Tooth formation begins prior to birth and their eventual morphology is dictated during this time. Dental anatomy is also a taxonomical science; it is concerned with the naming of teeth and the structures of which they are made. This information serves a practical purpose when rendering dental treatment.

Usually, there are 20 primary ("baby") teeth and 32 permanent teeth. Among primary teeth, 10 usually are found in the maxilla and the other 10 in the mandible. Among permanent teeth, 16 are found in the maxilla and the other 16 in the mandible. Most of the teeth have identifiable features that distinguishes them from others.

Contents


  • 1 Tooth development
  • 2 Identification
    • 2.1 Nomenclature
    • 2.2 Numbering systems
  • 3 Anatomic landmarks
    • 3.1 Crown and root
    • 3.2 Surfaces
    • 3.3 Cusp
    • 3.4 Cingulum
    • 3.5 Ridges
    • 3.6 Developmental groove
    • 3.7 Embrasures
    • 3.8 Mammelons
  • 4 Distinguishing characteristics of teeth
    • 4.1 Maxillary central incisor
    • 4.2 Maxillary lateral incisor
    • 4.3 Maxillary canine
    • 4.4 Maxillary first premolar
    • 4.5 Maxillary second premolar
    • 4.6 Maxillary first molar
    • 4.7 Maxillary second molar
    • 4.8 Maxillary third molar
    • 4.9 Mandibular central incisor
    • 4.10 Mandibular lateral incisor
    • 4.11 Mandibular canine
    • 4.12 Mandibular first premolar
    • 4.13 Mandibular second premolar
    • 4.14 Mandibular first molar
    • 4.15 Mandibular second molar
    • 4.16 Mandibular third molar
  • 5 References
//

Tooth development

Main article: Tooth development
Radiograph of lower right (from left to right) third, second, and first molars in different stages of development.
Radiograph of lower right (from left to right) third, second, and first molars in different stages of development.

Tooth development is the complex process by which teeth form from embryonic cells, grow, and erupt into the mouth. Although many diverse species have teeth, non-human tooth development is largely the same as in humans. For human teeth to have a healthy oral environment, enamel, dentin, cementum, and the periodontium must all develop during appropriate stages of fetal development. Primary (baby) teeth start to form between the sixth and eighth weeks in utero, and permanent teeth begin to form in the twentieth week in utero.[1] If teeth do not start to develop at or near these times, they will not develop at all.

A significant amount of research has focused on determining the processes that initiate tooth development. It is widely accepted that there is a factor within the tissues of the first branchial arch that is necessary for the development of teeth.[2] The tooth bud (sometimes called the tooth germ) is an aggregation of cells that eventually forms a tooth and is organized into three parts: the enamel organ, the dental papilla and the dental follicle.[3]

The enamel organ is composed of the outer enamel epithelium, inner enamel epithelium, stellate reticulum and stratum intermedium.[3] These cells give rise to ameloblasts, which produce enamel and the reduced enamel epithelium. The growth of cervical loop cells into the deeper tissues forms Hertwig's Epithelial Root Sheath, which determines the root shape of the tooth. The dental papilla contains cells that develop into odontoblasts, which are dentin-forming cells.[3] Additionally, the junction between the dental papilla and inner enamel epithelium determines the crown shape of a tooth.[4] The dental follicle gives rise to three important entities: cementoblasts, osteoblasts, and fibroblasts. Cementoblasts form the cementum of a tooth. Osteoblasts give rise to the alveolar bone around the roots of teeth. Fibroblasts develop the periodontal ligaments which connect teeth to the alveolar bone through cementum.[5]

Tooth development is commonly divided into the following stages: the bud stage, the cap, the bell, and finally maturation. The staging of tooth development is an attempt to categorize changes that take place along a continuum; frequently it is difficult to decide what stage should be assigned to a particular developing tooth.[2] This determination is further complicated by the varying appearance of different histologic sections of the same developing tooth, which can appear to be different stages.

Identification

Nomenclature

Teeth are named by their set, arch, class, type, and side. Teeth can belong to one of two sets of teeth: primary ("baby") teeth or permanent teeth. Often, "deciduous" may be used in place of "primary", and "adult" may be used for "permanent". "Succedaneous" refers to those teeth of the permanent dentition that replace primary teeth (incisors, canines, and premolars of the permanent dentition). Succedaneous dentition would refer to these teeth as a group. Further, the name depends upon which arch the tooth is found in. The term, "maxillary", is given to teeth in the upper jaw and "mandibular" to those in the lower jaw. There are four classes of teeth: incisors, canines, premolars, and molars. Premolars around found only in permanent teeth; there are no primary premolars. Within each class, teeth may be classified into different traits. Incisors are divided further into central and lateral incisors. Among premolars and molars, there are 1st and 2nd premolars, and 1st, 2nd, and 3rd molars. The side of the mouth in which a tooth is found may also be included in the name. For example, a specific name for a tooth may be "primary maxillary left lateral incisor."

Numbering systems

Main article: Dental notation

There are several different dental notation systems for associating information to a specific tooth. The three most commons systems are the FDI World Dental Federation notation, Universal numbering system (dental), and Palmer notation method. The FDI system is used worldwide, and the universal is used widely in the USA.

Although the Palmer notation was supposedly superseded by the FDI World Dental Federation notation, it overwhelming continues to be the preferred method used by dental students and practitioners in the United Kingdom.[6] It was originally termed the "Zsigmondy system" after the Austrian dentist Adolf Zsigmondy who developed the idea in 1861, using a Zsigmondy cross to record quadrants of tooth positions.[7]. The Palmer notation consists of a symbol (┘└ ┐┌) designating in which quadrant the tooth is found and a number indicating the position from the midline. Permanent teeth are numbered 1 to 8, and primary teeth are indicated by a letter A to E. The universal numbering system uses a unique letter or number for each tooth. The uppercase letters A through T are used for primary teeth and the numbers 1 - 32 are used for permanent teeth. The tooth designated "1" is the right maxillary third molar and the count continues along the upper teeth to the left side. Then the count begins at the left mandibular third molar, designated number 17, and continues along the bottom teeth to the right side. The FDI system uses a two-digit numbering system in which the first number represents a tooth's quadrant and the second number represents the number of the tooth from the midline of the face. For permanent teeth, the upper right teeth begin with the number, "1". The upper left teeth begin with the number, "2". The lower left teeth begin with the number, "3". The lower right teeth begin with the number, "4". For primary teeth, the sequence of numbers goes 5, 6, 7, and 8 for the teeth in the upper left, upper right, lower right, and lower left respectively.

As a result, any given tooth has three different ways to identify it, depending on which notation system is used. The permanent right maxillary central incisor is identified by the number "8" in the universal system. In the FDI system, the same tooth is identified by the number "11". The palmer system uses the number and symbol, 1┘, to identify the tooth. Further confusion may result if a number is given on a tooth without assuming (or specifying) a common notation method. Since the number, "12", may signify the permanent left maxillary first premolar in the universal system or the permanent right maxillary lateral incisor in the FDI system, the notation being used must be clear to prevent confusion.

Anatomic landmarks

Crown and root

The crown of a tooth can be used to describe two situations. The anatomic crown of a tooth is designated by the area above the cementoenamel junction (CEJ) and is consequently covered in enamel. Also, it is possible to describe the clinical crown of a tooth as any parts visible in the mouth, but frequently the anatomic crown is meant when the term is used. The majority of the crown is composed of dentin, with the pulp chamber found in the center. The crown is only found within bone before eruption into the mouth. Afterwards, it is almost always visible.

The root of a tooth can also be used as an anatomic or clinical situation. The anatomic root is found below the cementoenamel junction and is covered with cementum, whereas the clinical root is any part of a tooth not visible in the mouth. Similarly, the anatomic root is assumed in most circumstances. Dentin composes most of the root, which normally have pulp canals. The roots of teeth may be single in number or multiple. Canines and most premolars, except for maxillary first premolars, usually have one root. Maxillary first premolars and mandibular molars usually have two roots. Maxillary molars usually have three roots. The tooth is supported in bone by an attachment apparatus, known as the periodontium, which interacts with the root.

Surfaces

Surfaces that are nearest the cheeks or lips are referred to as facial, and those nearest the tongue are known as lingual. Facial surfaces can be subdivided into buccal (when found on posterior teeth nearest the cheeks) and labial (when found on anterior teeth nearest the lips). Lingual surfaces can also be described as palatal when found on maxillary teeth beside the hard palate.

Surfaces that aid in chewing are known as occlusal on posterior teeth and incisal on anterior teeth. Surfaces nearest the junction of the crown and root are referred to as cervical, and those closest to the apex of the root are referred to as apical. The words mesial and distal are also used as descriptions. Mesial signifies a surface closer to the median line of the face, which is located on a vertical axis between the eyes, down the nose, and between the contact of the central incisors. Surfaces further away from the median line are described as distal.

Cusp

A cusp is an elevation on an occlusal surface of posterior teeth and canines. It contributes to a significant portion of the tooth's surface. Maxillary and mandibular canines have one cusp. Maxillary premolars and the mandibular first premolars usually have two cusps. Mandibular second premolars frequently have three cusps--- one buccal and two lingual. Maxillary molars have two buccal cusps and two lingual cusps. A fifth cusp that may form on these teeth are known as the cusp of Carabelli. Mandibular molars may have five or four cusps.

Cingulum

A cingulum is a convexity found on the lingual surface of anterior teeth. It is frequently identifiable as an inverted V-shaped ridge,[8] and its appearance is comparable to a girdle.[9] All anterior teeth are formed from four centers of development, referred to as lobes. Three are located on the facial side of the tooth, and one on the lingual side. The cingulum forms from this lingual lobe of development.[10] The majority of a lingual surface's cervical third is made up of the cingulum.[11] On lower incisors, a cingulum usually is poorly developed or absent. Maxillary canines have a large, well-developed cingulum,[12] where as the cingulum of mandibular canines is smoother and rounded.[13]

Ridges

Ridges are any linear, flat elevations on teeth,[11] and they are named according to their location. The buccal ridge runs cervico-occlusally in approximately the center of the buccal surface of premolars. The labial ridge is one that runs cervico-incisally in approximately the center of the labial surface of canines. The lingual ridge extends from the cingulum to the cusp tip on the lingual surface of most canines. The cervical ridge runs mesiodistally on the cervical third of the buccal surface of the crown. These are found on all primary teeth but only on the permanent molars.

Cusp ridges are ridges that radiate from cusp tips. There are two marginal ridges, mesial and distal, present on all teeth. On anterior teeth, they are located on the mesial and distal borders of the lingual surface; on posterior teeth, they are located on the mesial and distal borders of the occlusal surface. Triangular ridges are those that project from the cusp tips of premolar and molars to the central groove. Transverse ridges are formed by the union of two triangular ridges on posterior teeth. The joining of buccal and lingual triangular ridges is usually named as an example. The oblique ridge is found on the occlusal surfaces of maxillary molars. It is formed by the union of the distal cusp ridge of the mesiolingual cusp and the triangular ridge of the distobuccal cusp. The oblique ridges usually forms the distal boundary of the central fossa.

Developmental groove

The teeth demonstrating the least number of developmental grooves are the mandibular central and lateral incisors.[14]

Embrasures

Embrasures are triangularly shaped spaces located between the proximal surfaces of adjacent teeth. The borders of embrasures are formed by the interdental papilla of the gingiva, the adjacent teeth, and the contact point where the two teeth meet. There are four embrassures for every contact area: facial (also called labial or buccal), lingual (or palatal), occlusal or incisal, and cervical or interproximal space. The cervical embrasure usually is filled by the interdental papilla from the gingiva.

Embrasures have three functions. They form spillways between teeth to direct food away from the gingiva. Also, they provide a mechanism for teeth to be more self cleansing. Lastly, they protect the gingiva from undue frictional trauma but also providing the proper degree of stimulation to the tissues.

Mammelons

Mammelons are usually found as three small bumps on the incisal edges of anterior teeth. They are the remnants of three lobes of formation of these teeth, the fourth lobe represented by the cingulum. Since this surface of the tooth is the first to wear away from attrition, mammelons may not visible on teeth of older people. Instead, the best chance to see this characteristic is soon after eruption of the tooth into the mouth.

Distinguishing characteristics of teeth

Maxillary central incisor

Main article: Maxillary central incisor

The maxillary central incisor is usually the most visible tooth, since it is the top center two teeth in the front of a mouth, and it is located mesial to the maxillary lateral incisor. As with all incisors, their function is for shearing or cutting food during mastication (chewing). There are no cusps on the teeth. Instead, the surface area of the tooth used in eating is called the incisal ridge or incisal edge. Though relatively the same, there are some minor differences between the primary maxillary central incisor and that of the permanent maxillary central incisor.

The overall length of the deciduous maxillary central incisor is 16 mm on average, with the crown being 6 mm and the root being 10 mm.[15] In comparison to the permanent maxillary central incisor, the ratio of the root length to the crown length is greater in the deciduous tooth. The diameter of the crown mesiodistally is greater than the length cervicoincisally, which makes the tooth appear wider rather than taller from a labial viewpoint.

The permanent maxillary central incisor is the widest tooth mesiodistally in comparison to any other anterior tooth. It is larger than the neighboring lateral incisor and is usually not as convex on its labial surface. As a result, the central incisor appears to be more rectangular or square in shape. The mesial incisal angle is sharper than the distal incisal angle. When this tooth is newly erupted into the mouth, the incisal edges have three rounded features called mammelons.[16] Mammelons disappear with time as the enamel wears away by friction.

Maxillary lateral incisor

The maxillary lateral incisor is the tooth located distally from both maxillary central incisors of the mouth and mesially from both maxillary canines. As with all incisors, their function is for shearing or cutting food during mastication. There are no cusps on the teeth. Instead, the surface area of the tooth used in eating is called an incisal ridge or incisal edge. Though relatively the same, there are some minor differences between the deciduous (baby) maxillary lateral incisor and that of the permanent maxillary lateral incisor.

Maxillary canine

The maxillary canine is the tooth located laterally from both maxillary lateral incisors of the mouth but mesially from both maxillary first premolars. Both the maxillary and mandibular canines are called the "cornerstone" of the mouth because they are all located three teeth away from the midline, and separate the premolars from the incisors. The location of the canines reflect their dual function as they complement both the premolars and incisors during mastication, commonly known as chewing. Nonetheless, the most common action of the canines is tearing of food. There is a single cusp on canines, and they resemble the prehensile teeth found in carnivorous animals. Though relatively the same, there are some minor differences between the deciduous (baby) maxillary canine and that of the permanent maxillary canine. It is the longest tooth in total length, from root to the incisal edge, in the mouth.

Maxillary first premolar

The maxillary first premolar is the tooth located laterally from both the maxillary canines of the mouth but mesially from both maxillary second premolars. The function of this premolar is similar to that of canines in regard to tearing being the principal action during mastication. There are two cusps on maxillary first premolars, and the buccal cusp is sharp enough to resemble the prehensile teeth found in carnivorous animals. There are no deciduous maxillary premolars. Instead, the teeth that precede the permanent maxillary premolars are the deciduous maxillary molars.

Maxillary second premolar

The maxillary second premolar is the tooth located laterally from both the maxillary first premolars of the mouth but mesially from both maxillary first molars. The function of this premolar is similar to that of first molars in regard to grinding being the principle action during mastication. 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 maxillary premolars. Instead, the teeth that precede the permanent maxillary premolars are the deciduous maxillary molars.

Maxillary first molar

The maxillary first molar is the tooth located laterally from both the maxillary second premolars of the mouth but mesially from both maxillary second molars. The function of this molar is similar to that of all molars in regard to grinding being the principle action during mastication. There are usually four cusps on maxillary molars, two on the buccal and two palatal. There are great differences between the deciduous maxillary molars and those of the permanent maxillary molars, even though their function are similar. It is important to note that the permanent maxillary molars are not considered to have any teeth that precede it. Despite being named molars, the deciduous molars are followed by permanent premolars.

Maxillary second molar

The maxillary second molar is the tooth located laterally from both the maxillary first molars of the mouth but mesially from both maxillary third molars. This is true only in permanent teeth. In deciduous teeth, the maxillary second molar is the last tooth in the mouth and does not have a third molar behind it. The function of this molar is similar to that of all molars in regard to grinding being the principle action during mastication. There are usually four cusps on maxillary molars, two buccal and two palatal. There are great differences between the deciduous maxillary molars and those of the permanent maxillary molars, even though their function are similar.

Maxillary third molar

The maxillary third molar is the tooth located laterally from both the maxillary second molars of the mouth with no tooth posterior to it in permanent teeth. In deciduous teeth, there is no maxillary third molar. The function of this molar is similar to that of all molars in regard to grinding being the principle action during mastication. There are usually four cusps on maxillary molars, two buccal and two palatal. Nonetheless, for this tooth, there are great variances among third molars, and a specific description of a third molar will not hold true in all cases.

Mandibular central incisor

The mandibular central incisor is the tooth located on the jaw, adjacent to the midline of the face. It is mesial from both mandibular lateral incisors. As with all incisors, its function include shearing or cutting food during mastication. There are no cusps on the tooth. Instead, the surface area of the tooth used in eating is called an incisal ridge or incisal edge. Though the two are similar, there are some minor differences between the deciduous mandibular central incisor and that of the permanent mandibular central incisor.

Mandibular lateral incisor

The mandibular lateral incisor is the tooth located distally from both mandibular central incisors of the mouth and mesially from both manibular canines. As with all incisors, their function is for shearing or cutting food during mastication. There are no cusps on the teeth. Instead, the surface area of the tooth used in eating is called an incisal ridge or incisal edge. Though relatively the same, there are some minor differences between the deciduous mandibular lateral incisor and that of the permanent mandibular lateral incisor.

Mandibular canine

The mandibular canine is the tooth located distally from both mandibular lateral incisors of the mouth but mesially from both mandibular first premolars. Both the maxillary and mandibular canines are called the "cornerstone" of the mouth because they are all located three teeth away from the midline, and separate the premolars from the incisors. The location of the canines reflect their dual function as they complement both the premolars and incisors during mastication, commonly known as chewing. Nonetheless, the most common action of the canines is tearing of food. There is a single cusp on canines, and they resemble the prehensile teeth found in carnivorous animals. Though relatively the same, there are some minor differences between the deciduous mandibular canine and that of the permanent mandibular canine.

Mandibular first premolar

The mandibular first premolar is the tooth located laterally from both the mandibular canines of the mouth but mesially from both mandibular second premolars. The function of this premolar is similar to that of canines in regard to tearing being the principle action during mastication. Mandibular first premolars have two cusps. The one large and sharp is located on the buccal side of the tooth. Since the lingual cusp is small and nonfunctional, which means it is not active in chewing, the mandibular first premolar resembles a small canine. There are no deciduous mandibular premolars. Instead, the teeth that precede the permanent mandibular premolars are the deciduous mandibular molars.

Mandibular second premolar

The mandibular second premolar is the tooth located distally from both the mandibular first premolars of the mouth but mesially from both mandibular first molars. The function of this premolar is to assist the mandibular first molar during mastication. Mandibular second premolars have three cusps. There is one large cusp on the buccal side of the tooth. The lingual cusps are well developed and functional, which means the cusps assist during chewing. Therefore, whereas the mandibular first premolar resembles a small canine, the mandibular second premolar is more like the first molar. There are no deciduous mandibular premolars. Instead, the teeth that precede the permanent mandibular premolars are the deciduous mandibular molars.

Mandibular first molar

The mandibular first molar, also known as the 6 year molar, is the tooth located distally from both the mandibular second premolars of the mouth but mesially from both mandibular second molars. It is located on the mandibular arch of the mouth, and generally opposes the maxillary first molars and the maxillary 2nd premolar. This arrangement is known as Class I occlusion. The function of this molar is similar to that of all molars in regard to grinding being the principal action during mastication. There are usually five well-developed cusps on mandibular first molars: two on the buccal, two palatal, and one distal. There are great differences between the deciduous mandibular molars and those of the permanent mandibular molars, even though their function are similar.

Mandibular second molar

The mandibular second molar is the tooth located distally from both the mandibular first molars of the mouth but mesially from both mandibular third molars. This is true only in permanent teeth. In deciduous teeth, the mandibular second molar is the last tooth in the mouth and does not have a third molar behind it. The function of this molar is similar to that of all molars in regard to grinding being the principle action during mastication. Though there is more variation between individuals to that of the first mandibular molar, there are usually four cusps on mandibular second molars: two buccal and two palatal. There are great differences between the deciduous mandibular molars and those of the permanent mandibular molars, even though their function are similar.

Mandibular third molar

The mandibular third molar, commonly known as a wisdom tooth, is the tooth located distally from both the mandibular second molars of the mouth with no tooth posterior to it in permanent teeth. In deciduous teeth, there is no mandibular third molar. The function of this molar is similar to that of all molars in regard to grinding being the principle action during mastication. For this tooth, there are great variances among third molars, and a specific description of a third molar will not hold true in all cases.

References

  1. ^ A. R. Ten Cate, Oral Histology: Development, Structure, and Function, 5th ed. (Saint Louis: Mosby-Year Book, 1998), p. 95. ISBN 0-8151-2952-1.
  2. ^ a b A. R. Ten Cate, Oral Histology: Development, Structure, and Function, 5th ed. (Saint Louis: Mosby-Year Book, 1998), p. 81. ISBN 0-8151-2952-1.
  3. ^ a b c *University of Texas Medical Branch. "Lab Exercises: Tooth development." Page found here.
  4. ^ A. R. Ten Cate, Oral Histology: Development, Structure, and Function, 5th ed. (Saint Louis: Mosby-Year Book, 1998), pp. 86 and 102. ISBN 0-8151-2952-1.
  5. ^ *Ross, Michael H., Gordon I. Kaye, and Wojciech Pawlina. Histology: a text and atlas. 4th edition, p. 453. 2003. ISBN 0-683-30242-6.
  6. ^ Blinkhorn A, Choi C, Paget H (1998). "An investigation into the use of the FDI tooth notation system by dental schools in the UK.". Eur J Dent Educ 2 (1): 39-41. PMID 9588962.
  7. ^ Huszár G (1989). "[The role of the life and works of Adolf Zsigmondy and Ottó Zsigmondy in the history of dentistry]". Fogorv Sz 82 (12): 357-63. PMID 2689240.
  8. ^ Gray, Henry. XI. Splanchnology. 2a. The Mouth, from "Gray's Anatomy of the Human Body". 20th U.S. edition. 1918.
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  11. ^ a b Ash, Major M. and Stanley J. Nelson. Wheeler’s Dental Anatomy, Physiology, and Occlusion. 8th edition. 2003. p. 11. ISBN 0-7216-9382-2.
  12. ^ Ash, Major M. and Stanley J. Nelson. Wheeler’s Dental Anatomy, Physiology, and Occlusion. 8th edition. 2003. p. 198. ISBN 0-7216-9382-2.
  13. ^ "Maxillary and Mandibular Canines", hosted on the University of Oklahoma College of Dentistry website. Page accessed May 13, 2007.
  14. ^ Ash, Major M. and Stanley J. Nelson. Wheeler’s Dental Anatomy, Physiology, and Occlusion. 8th edition. 2003. p. 177. ISBN 0-7216-9382-2.
  15. ^ Ash, Major M. and Stanley J. Nelson. Wheeler’s Dental Anatomy, Physiology, and Occlusion. 8th edition. 2003. p. 75. ISBN 0-7216-9382-2.
  16. ^ The Permanent Incisor Teeth, hosted by the University of Illinois at Chicago (UIC), accessed on June 8, 1006.

 

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