mazen doumani dental anatomy
TRANSCRIPT
Dr Mazen D Doumani
Master in dental sciences
Reference:
Dental anatomy: The study of the development, morphology, function, and identity of each tooth in the
human dentition. As well as: The way in wich the teeth relate to other teeth in the same dental arch and to teeth in the opposite arch.
All phases of dentistry
Dental anatomy
occlusion physiology
Esthetic
Psychological
periodontal
Dental anatomy
Occlusion
Esthetics
Phonetics
Formation of the dentition Humans have two sets of teeth in their lifetime.
First set : primary or deciduous dentition, begins
at 14th weeks in utero and is completed at about 3 years postnatally .the first teeth begin to appear in mouth at 6th month and the last one at 28th _+4month.
Second set : permanent dentition completed at 14-15
year for second permanent molar(but transition or mixed dentition from 6th -12th year because the human has decideouos and permanent teeth).
Why mixed period of dentition is a difficult time for young child ? Missing teeth
Teeth of different colors
Crowding , malposed teeth .
exfoliation
shedding
=
Maxillary teeth Mandibular teeth
Maxilla is stationary
Mandible is movable
Midline
Quadrants Upper right
Lower right
Upper left
Lower left
Anterior and Posterior teeth
anterior posterior
Occlusion The manner in wich the mandibular teeth contact the maxillary teeth
permanent
Deciduous
Function of teeth
Incisores : cutting
Canine : tearing
Premolar : tearing and grinding
Molar : grinding
Formula for human teeth Deciduous : I2\2 C1\1 M2\2 = 10
I 2\2 means incisors 2 upper , 2 lower
C2\2 means canines 1 upper ,1 lower
M2\2 means molars 2 upper , 2 lower
The total =10 in two quadrant
10 * 2 =20 tooth(milk or baby tooth)in
full mouth
Permanent :I 2\2 C 1\1 P 2\2 M 3\3
Total = 16 in two quadrant
16*2=32 in full mouth
Universal system Deciduous Permanent
Zsigmondy /palmer notation
FDI numbering system
Enamel
Cementum
Dentin
Hard Tissues
Pulpal tissue:
chamber
Root canal
Soft Tissue
PULP
Blood and Nerve supply
Cutting surfaces: - Incisal ridge or edge - Cusps
Alveolar process
Surfaces & ridges Incisor, canine : the crown of each one has 4 surfaces and a ridge
Molar ,premolar : the crown of each one has five surfaces
Facial surfaces
Buccal surface Labial surface
Lingual surface
Lingual or
palatal
Palate
The importance of the contour
Occlusal surface
INCISAL SURFACES
Mesial and distal surfaces
Mesial
distal
Cusp Is an elevation or mound on crown portion of a tooth;
making up a divisional part of the occlusal surface.
Tubercle Is a smaller elevation on some portion of the crown
produced by an extra formation of enamel
Cingulum Latin word for”girdle”
It is the lingual lobe of an anterior tooth . It makes the cervical third of the lingual surface .
Ridge Any linear elevation on the surface of of the tooth and
is named according to its location Examples: - incisal ridge - marginal ridge - buccal ridge
Marginal ridges Are rounded borders of enamel that form the mesial
and distal margins of the occlusal surfaces of molars and premolars
and the mesial and distal margins of the incisors and canine
Triangular ridges Desend from the tip of the cusp of molar and premolar
toward the central part of the occlusal surface .
How do they name? according to the cusp they belong to.
Example:buccal cusp ridge.
Comparison between transverse and oblique ridges
Fossa An irregular depression or concavity
Ligual fossae: are on lingual surface of incisors
Triangular fossa Located adjacent to the marginal ridges on the
occlusal surfaces of posterior teeth. Two types of triangular fossae are mesial and distal
Central fossae Are on the occlusal surfaces of molars ,they formed by
the convergence of ridges terminating at a central point in the bottom of the depression where there is a junction of grooves
sulcus is a long depression or valley in the surface of a tooth
between ridges and cusps, the inclines of which meet at an angle. A sulcus has a developmental groove at the junction of its inclines
developmental groove a shallow groove or line between the primary parts of
the crown or root
Buccal and lingual grooves
supplemental groove A less destinct, shallow linear depression on the
surface of a tooth, but it is supplemental to adevelopmental groove, and does not mark the junction of primary parts
MLCR, mesiolingual cusp ridge; LDG, lingual developmental groove; DLCR, distolingual cusp ridge; DTF, distal triangular fossa (outlined area); DCR, distal cusp ridge; DBDG, distobuccal developmental groove; DBCR, distobuccal cusp ridge; MTF, mesial triangular fossa (outlined area); SG, a supplemental groove.
Pits Small pinoint depressions located at the junctions of
developmental groove or terminals of those grooves.
Lobe One of the primary sections of formation in the
development of the crown .
Cusps and mamelons are representative of lobes .
Mamelon:one of three tubercles on the cutting edge of a newly erupted incisor tooth.
Roots
Division into thirds
Line angle Is formed by the junction of two surfaces and derives
its name from the combination of the two surfaces that join
Point angles Is formed by the junction of three surfaces and derives
its name from the combination of the three surfaces that join
Measurement of tooth dimensions
Clinical and anatomical crown
Malformations Include disturbances in:
1- form .
2- color.
3- arrangement.
4- structure(enamel hypoplasia).
Summary of schematic outlines Triangles:
six anterior teeth , maxillary and mandibular
A-mesial aspect
B-distal aspect
Summary of schematic outlines
trapezoids:
I. Trapezoids with longest uneven side toward occlusal or incisal surface:
A. All anterior teeth , maxillary and mandibular 1-labial aspect 2-lingual aspect
B. All posterior teeth 1- buccal aspect 2- lingual aspect
Summary of schematic outlines
trapezoids:
II. Trapezoids with shortest uneven side toward occlusal or incisal surface:
A. All maxillary posterior teeth
1-mesial aspect
2- distal aspect
Summary of schematic outlines
rhomboids:
All mandibular posterior teeth
1-mesial aspect
2- distal aspect
Interproximal form Proximal contacts of approximating teeth in the arch
protect the soft tissue(gingiva) between the teeth and referred to as interproximal space
Interdental papilla
Interproximal form Normally the gingiva covers part of cervical third of
the crown and fills the interproximal spaces.
The gingival line follows the curvature but not necessarily the level of the cervical line .
Interproximal form The cervical line is a stable anatomical demarcation.
The level of gingival line is variable.
Absence of bone over the root of the tooth is called dehisence(clift) or fenestration(window).
Interproximal form Cervicoenamel ridge
It is also called cervical ridge.
It is curvature on the crown at the cervical third above the cervical lin.
This ridge shouldn’t be overcontoured or undercontoured in full-crown restorations.
Root form Root form(shape and length) is associated with:
- overall form
- work Of the tooth
Root form Mesial view of the anterior tooth will show that the incisal
ridge or cusp is centered over the root
The measurment from cusp tip to cusp tip buccolingually is much less than the buccolingual diameter of the root base
Contact area A part of mesial or distal surface wich contacts the
neighbouring tooth.
point
line
area
diastema is a space that exists between two adjacent teeth in the
same arch that is not the result of a missing tooth.
It is most commonly seen between the maxillary right and left central incisors, but can occur between any teeth
Embrasures(spillways) when two teeth in the same arch in contact ,their
curvature adjacent to the contact area form spillway space called embrasures.
Significance of Embrasure form Serves as a spillway for food material during
mastication
Prevents food from being forced through the contact area and injuring the periodontal tissues.
Also, Enhances the self-cleansing process of the tooth by exposing the surfaces to oral fluids, mechanical cleansing, and friction from the tongue, lips, and cheeks
Overlap of the teeth
Curvatures of the Occlusal Plane
Curve of Spee Curve of Wilson