Nomenclature Flashcards
Dental Anatomy
the study of the structure of the teeth and their correlated parts.
the branch of gross anatomy concerned with the morphology of teeth
Dental Arches
- Maxillary teeth are in the upper dental arch. The maxilla is the upper jaw member.
- Mandibular teeth are in the lower dental arch. The mandible is the lower jaw member.
- The mandible is the movable member of the two jaws, while the maxilla is stationary or fixed.
Maxilla and Mandible
- The maxilla is the upper jaw member.
- The mandible is the lower jaw member.
- The mandible is the movable member of the two jaws, while the maxilla is stationary or fixed.
Midline
- Midline - the imaginary vertical line which divides each arch, as well as the body, into approximately equal halves.
- In the mouth, this creates four quadrants: maxillary right, maxillary left, mandibular right mandibular left.
How many teeth do fully dentate adults normally have?
Mid-sagittal Plane
- From an anatomic standpoint, the term mid-sagittal plane is preferable to midline.
- It is common for the right and left halves to be symmetrical, i.e., the right and left sides are mirror images of each other.
Terms for Function
Occlusion
Mastication
Comminution
You have to have o to have m to have c
One leads to the other
Occlusion
•overall approach to health
Mastication
the process of biting or chewing of food.
Comminution
the crushing of food particles into small pieces.
Classifications of Dentitions
Heterodont
Homodont
Monophyodont
Diphyodont
Polyphyodont
Heterodont
a dentition in which there are different types of teeth to perform different functions in the mastication process (i.e. - the human dentition).
Homodont
nHomodont - a dentition in which all of the teeth are the same in form and type (i.e. - some lower vertebrates, example: alligators).
What type of creature continuously develops new teeth throughout it’s life?
Shark
Monophyodont
one set of teeth during life,
examples: rats, seals, walruses.
Teeth continually grow..thats why they have to continually knaw
Diphyodont
two separate sets of teeth or dentitions. Note - man is a diphyodont.
Polyphyodont
nmore than two (or continuous) sets of teeth are developed throughout life, example: shark.
They keep replacing their teeth
Deciduous Dentition
- The deciduous dentition is the first dentition of man. It is also known as the primary dentition.
- There are twenty total deciduous teeth.
- All deciduous teeth are normally erupted by two years (24-26 months) of age.
- The roots of primary teeth are normally completed one year after eruption.
- Other names for the deciduous teeth include “baby teeth” and “milk teeth.”
Roots of all primary teeth are completely formed by age what?
3-4 years would be your answer
Deciduous Dentition - Eruption Sequence
- As a general rule, mandibular deciduous teeth normally precede their maxillary counterparts in eruption.
- In general the deciduous teeth normally erupt in order from the front of the mouth toward the back. *Exception, the canines in each quadrant normally erupt after the first molars.
Permanent Dentition
- The permanent dentition includes the teeth of the second or adult dentition.
- There are normally 32 permanent teeth.
- The permanent teeth erupt from 6-21 years of age.
- The roots of permanent teeth are normally completed 2-3 years after eruption.
Permanent Dentition - Eruption Sequence
- The permanent mandibular teeth normally precede their maxillary counterparts in eruption.
- Except for the first molars, the permanent mandibular teeth exhibit a perfect anterior to posterior order. *Note - in the maxillary arch, not only is the first molar out of order, but the canine normally follows both of the premolars.
- First molars erupt first
Dentition Periods
- primary dentition period
- mixed dentition period
- permanent dentition period
primary dentition period
_________-_______
ends with _____ which is usually the
nThe primary dentition period is that period during which only deciduous teeth are present.
nThe primary dentition period occurs from approximately six months to six years of age.
nThe primary dentition period ends with the eruption of the first permanent tooth, which is normally the mandibular first molar.
mixed dentition period
time
ends when _______ which is normally the
During the mixed dentition period, both deciduous and permanent teeth are present.
The mixed dentition period lasts from approximately 6 years to 12 years of age.
The mixed dentition period ends with the exfoliation of the last deciduous tooth, which is normally the maxillary canine or second molar.
Permanent dentition period
begins
Permanent dentition period - when only permanent teeth are present. It begins with the exfoliation of the last deciduous tooth.
The permanent dentition period begins at approximately twelve years of age and continues through the rest of life.
Exfoliation
In order for a permanent tooth to erupt into a space where a deciduous tooth is located, the deciduous tooth must first be shed or exfoliated.
Resorption
Resorption
is the natural process by which the deciduous roots are “melted away” to allow for exfoliation or shedding.
Succedaneous Teeth
Succedaneous teeth are permanent teeth which replace or succeed exfoliated deciduous teeth.
The succedaneous teeth are the permanent incisors, canines and premolars.
The permanent molars are not succedaneous because they erupt in spaces which were previously unoccupied.
The first succedaneous tooth to erupt is the mandibular central incisor.
Dental Formulae
- A dental formula describes the dentition on one side of the mouth as to the number and type of teeth.
- The dental formula for the permanent dentition is as follows: I2/2 C1/1 P2/2M3/3 X 2 =32.
- The dental formula for the deciduous dentition is as follows: I2/2 C1/1 M2/2 X 2 = 20.
- Typical permanent dental formular= 16 (only one side of mouth)
- For whole mouth need to multiply by 2 = 32
- I2/2: Incisors 2 over 2
C1/1: Canine 1 over 1
P2/2: Premolar 2 over 2
M3/3: Molars 3 over 3
The Dental Formulae is based on
1.The maxillary and mandibular arches on one side
Anterior vs Posterior
Deciduous Teeth (each quadrant)
- Anterior: 2 Incisor, 1 Canine
- Posterior2 Molars
Permanent Teeth
- Anterior: 2 Incisors, 1 Canine
- Posterior: 2 Pre molars, 3 Molars
Tooth Surfaces
Mesial
Distal
Proximal
Incisal
Occlusal
Labial
Buccal
Facial
Mesial
nthe surface closest to the midline.
Distal
the surface furthest away from the midline.
nProximal -
the combined term for mesial and distal surfaces.
Incisal -
the biting edge of an anterior tooth.
On a newly erupted anterior tooth, the incisal surface may be referred to as the incisal ridge.
After incisal wear has occurred, the incisal surface may be referred to as the incisal edge.
Occlusal
the chewing surfaces of posterior teeth.
Labial
nBuccal -
the “outside” surface of posterior teeth which is toward the cheek.
Facial -
nthe combined term for labial and buccal surfaces.
Lingual -
the inside surface which is towards the tongue
In the maxillary arch, the term palatal is sometimes used.
Line Angle
A line angle is the angle formed by the junction of two crown surfaces.
The name of the line angle is derived by combining the names of the two surfaces involved.
For an individual tooth, there are a total of eight line angles.
Line Angles - Anterior
Mesiolabial
Mesiolingual
Distolabial
Distolingual
Labio-incisal
Linguo-incisal
Mesio-incisal
Disto-incisal
Line Angles - Posterior
Mesiobuccal
Mesiolingual
Distobuccal
Distolingual
Bucco-occlusal
Linguo-occlusal
Disto-occlusal
Mesio-occlusal
What is a Point Angle?
The junction of three tooth surfaces
A point angle is the angle formed by the junction of three crown surfaces.
The name of the point angle is derived by combining the names of the three surfaces involved.
For an individual tooth, there are a total of four point angles
Rules for Naming -
Line and Point Angles
- The names of the surfaces are combined by dropping the “al” from the end of the first surface for line angles (first two surfaces for point angles) and substituting an “o.”
- When two vowels are adjacent, they are separated by a hyphen.
- Note - the word mesial or distal (if present) goes first. The word incisal or occlusal (if present) goes last.
Point Angles - Anterior
nMesiolabio-incisal
nMesiolinguo-incisal
nDistolabio-incisal
nDistolinguo-incisal
Point Angles - Posterior
nMesiobucco-occlusal
nMesiolinguo-occlusal
nDistobucco-occlusal
nDistolinguo-occlusal
Universal Numbering System
nThe maxillary right third molar is #1, the second molar is #2 and so forth around the maxillary arch to the maxillary left third molar, which is #16.
nThe mandibular left third molar is #17. The system continues around the mandibular arch to the mandibular right third molar, which is #32.
Tooth Tissues
n1. Enamel
n2. Dentin
n3. Cementum
n4. Pulp
Enamel
Enamel - the___ ______ tissue covering the anatomical crown of a tooth. It is the _____ ____ ____ ___
The hardness of enamel is similar to that of a high quality ____
Enamel is ________
Has low tensile strength when unsupported
Without Dentin, it fractures
The hardness of enamel helps the tooth ________
Enamel ______
There are no cells that create new enamel
Enamel can demineralize and remineralize depending on pH of saliva (can go from harder to softer) but there are no new cells
- Enamel - the hard, mineralized tissue covering the anatomical crown of a tooth. It is the hardest living body tissue.
- The hardness of enamel is similar to that of a high quality stainless steel.
- Enamel is brittle, especially when not supported by sound underlying dentin.
- Has low tensile strength when unsupported
- Without Dentin, it fractures
- The hardness of enamel helps the tooth resist wear.
- Enamel does not repair itself.
- There are no cells that create new enamel
- Enamel can demineralize and remineralize depending on pH of saliva (can go from harder to softer) but there are no new cells
Dentin
Dentin - the ___ tissue which forms the______. It surrounds the _____
It is covered by the
Dentin may
It is
Dentin - the hard tissue which forms the main body of the tooth. It surrounds the pulp cavity.
It is covered by the enamel in the anatomical crown and by cementum in the anatomical root.
Dentin may repair itself.
It is softer than enamel, but it is harder than cementum.
Cementum
Cementum - the layer of___ _____ tissue which covers the ____ of a tooth.
Cementum has a ____ color.
The layer of cementum on the root is relatively____.–> like a sheet of paper
Cementum is ___ than both enamel and dentin.
Cementum - the layer of hard, bonelike tissue which covers the anatomical root of a tooth.
Cementum has a yellowish color.
The layer of cementum on the root is relatively thin.–> like a sheet of paper
Cementum is softer than both enamel and dentin.
Pulp
Pulp - the___ _____ tissue which occupies the___ ____
It contains the tooth’s ____ ____y in the form of ___ ____, as well as the ___ ___.
Gives pain to tooth when nerve gets irritated
The ____ of the ___ ___ are lined with ____s, which are responsible for ____ ____.
Pulp - the living soft tissue which occupies the pulp cavity.
It contains the tooth’s nutrient supply in the form of blood vessels, as well as the nerve supply.
Gives pain to tooth when nerve gets irritated
The walls of the pulp cavity are lined with odontoblasts, which are responsible for dentin formation.
Pulp cavity -
the entire internal cavity of a tooth which contains the pulp.
nPulp chamber
- the enlarged portion of the pulp cavity, which is found mostly in the anatomic crown of the tooth.
Pulp horns
the usually pointed incisal or occlusal elongations of the pulp chamber
Note - the number of pulp horns in a tooth often corresponds to the number of lobes or cusps present.
Pulp canal(s) -
that portion of the pulp cavity which is located in the root(s) of the tooth. A pulp canal may also be referred to as a root canal.
Supporting Structures
Alveolar process
Alveolus
Periodontal ligament
Gingiva
Alveolar process -
the ___ ____ entity which ___ and ____ all the teeth in each jaw member.
the entire bony entity which surrounds and supports all the teeth in each jaw member.
nAlveolus -
the ___ ____ or portion of the ___ ___, into which an ___ ___ is set. (Plural - ____)
the bony socket or portion of the alveolar process, into which an individual tooth is set. (Plural - alveoli)
Periodontal ligament
the ___ attachment of the tooth___ to the_____
Note - the periodontal ligament is also referred to as the PDL.
the fibrous attachment of the tooth cementum to the alveolar bone.
Note - the periodontal ligament is also referred to as the PDL.
Gingiva -
the ___ tissue enclosed by ____ ____ that covers the____ ____ and surrounds the___ of the teeth. (Plural - ___)
Note - the gingiva are commonly referred to as the “gum” or “gums.”
the fibrous tissue enclosed by mucous membrane that covers the alveolar processes and surrounds the necks of the teeth. (Plural - gingivae)
Note - the gingiva are commonly referred to as the “gum” or “gums.”
Anatomical Crown and Root
Anatomical crown - that portion of the tooth which is covered by enamel.
Anatomical root - that portion of the tooth which is covered by cementum.
Clinical Crown and Root
Clinical crown - that portion of the tooth which is visible in the mouth.
Clinical root - that portion of the tooth which is not visible in the mouth.
We could have anatomical enamel as part of the clinical root!
On a healthy tooth, the gingival tissue is above cemento-enamal jcn
This jcn separates anatomical crown and root
If you have young patient, part of anatomical crown will be under the gum line
Vise versa occurs as patient ages
As they age the tissues recede
Clinical crown will include part of anatomical root bc tissues show part of root
Anatomic Crown vs.
Clinical Crown
The anatomic crown and root are constant entities throughout life. They are separated by the CEJ or cervical line.
The clinical crown and root depend on the level of the tooth’s investing structures and may change throughout life.
Thirds of Crown
Proximal View
In a proximal view, a crown is divided into vertical thirds: (1) labial or buccal, (2) middle and (3) lingual.
A crown may also be divided into horizontal thirds: (1) incisal or occlusal (2) middle and (3) cervical.
Thirds of Root
The root is divided into horizontal thirds only: the cervical, middle and apical thirds.
The term cervical denotes towards the cervix (neck of the tooth) or cervical line.
The cervical thirds of the root and crown are adjacent to each other and are separated by the cervical line.
Crown Elevations
Cusps
Ridges
Cusp ridges
Triangular ridges
Inclined plane
Transverse ridge
Oblique ridge
Cingulum
Mamelons
Cusps
- elevated and usually pointed projections of various sizes and shapes on the crowns of canines and posterior teeth.
Cusps form the bulk of the occlusal surfaces of posterior teeth and the incisal portion of canines
Incisors: 0 cusps
Canine: 1
Premolar:2-3
Molar 4 or more
Ridges -
linear and usually convex elevations on the surfaces of the crowns of teeth. May or may not be part of a cusp.
Cusp ridges
each cusp has 4 cusp ridges extending in four different directions (mesial, distal, facial and lingual).
Triangular ridges -
linear ridges which descend from the cusps of posterior teeth towards the central area of the occlusal surface.
Inclined plane
- the sloping area found between two cusp ridges. Each cusp normally exhibits four inclined planes.
The inclined planes are named by the direction which they face - mesiobuccal, distobuccal, mesiolingual and distolingual.
Transverse ridge
Transverse ridge - the combination of two triangular ridges, which transversely cross the occlusal surface of a posterior tooth to merge with each other.
One triangular ridge is from a buccal cusp and the other is from a lingual cusp.
Oblique ridge
a combination of one triangular ridge and one cusp ridge found only on maxillary molars.
The oblique ridge is formed by the junction of the triangular ridge (lingual ridge) of the distobuccal cusp and the distal ridge of the mesiolingual cusp.
The cingulum is located:
1.On the lingual of an anterior tooth.
Cingulum
a large rounded elevation on the lingual surface of all permanent and deciduous anterior teeth.
The cingulum encompasses the entire cervical third of the lingual surface.
Mamelons
small, rounded projections of enamel that are found on the incisal ridges of newly erupted incisors.
Mamelons are worn away rather soon after eruption if the tooth contacts its antagonist(s) during functional movements.
If you look in patients mouth: 32 yrs old and has mamelons
Problem: anterior open bite, front teeth don’t touch
Tongue thrust or sucking thumb
Crown Depressions
Fossa
Developmental (primary) groove
Supplemental (secondary) groove
Pit
Fossa
- an irregular, usually rounded or triangular depression or concavity on the crown of a tooth. (Plural - fossae)
There is normally a rather large, shallow fossa on the lingual surface of anterior teeth.
Posterior teeth exhibit two or more fossae of varying size and shape on the occlusal surface.
Developmental (primary) groove
- a groove or line which usually notes the coalescence of the primary parts or lobes of the crown of a tooth.
Supplemental (secondary) groove -
an auxiliary groove that branches from a developmental groove. It is normally not as deep as a primary groove
A small, depressed area where developmental grooves join or terminate is called?
1.A pit
Pit
n- a small, depressed area where developmental grooves join or terminate.
nA pit is normally found in the deepest portion of a fossa.
Contact Areas
- the area on a proximal surface of the crown that contacts the adjacent tooth in the same arch. Depending on its location, it is called the mesial contact area or the distal contact area.
- All teeth in each quadrant have two contact areas, except the most distal tooth which has no distal contact area.
How many contact areas does tooth 17 or 16 have?
1
What are only teeth in mouth that have mesial to mesial contacts 14
The 4 central incisors are mesial to mesial
