Download BASIC ORAL ANATOMY

BASIC ORAL
ANATOMY
Oral Cavity (mouth)
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The entire oral cavity is lined with mucous
membrane tissue. The oral cavity consists
of the following two areas:
1. The vestibule is the space between the
teeth and the inner mucosal lining of the
lips and checks.
2. The oral cavity proper is the space
contained within the upper and lower
dental arches.
The Dentitions
 The term dentition is used to describe the natural
teeth in the jawbones.
 Primary dentition is the first set of 20 primary
teeth. Also referred to as “baby teeth” or
“deciduous teeth”
 Permanent dentition refers to the 32 secondary
or “adult” teeth.
 Mixed dentition occurs when both primary and
permanent teeth are present, usually between the
ages of 6 to 12.
Dental arches
 The maxillary arch (upper arch), actually
part of the skull, is fixed and not capable of
movement. The teeth in the upper arch are
set in the maxilla, the maxillary bone.
 The mandibular arch (lower arch) is
capable of movement through the action of
the temporomandibular joint. The mandible,
the mandibular bone supports the teeth in
the lower arch.
Quadrants
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1.
2.
3.
4.
An imaginary midline divides each arch
into a left half and a right half. When the
maxillary and mandibular arches are each
divided into halves the resulting four
sections are called quadrants, as follows:
Maxillary right quadrant
Maxillary left quadrant
Mandibular right quadrant
Mandibular left quadrant
Directions of the Oral Cavity
 Anterior means toward the front of the
mouth.
 Posterior means toward the back of the
mouth.
 Medial means toward the middle or toward
the middle of the arch.
 Lateral means toward the side or toward the
outside of the mouth.
 Mesial means toward the mid-line of the
dental arch.
 Distal means away from the mid-line of the
dental arch.
Eruption & Exfoliation
 Eruption is the movement of the tooth
through the surrounding tissues so that
more of the tooth becomes visible in the
mouth.
 Exfoliation is the process by which the roots
of the baby tooth are resorbed and
dissolved until so little root remains that the
baby tooth falls out.
Occlusion
 Occlusion is the relationship of the
mandibular and maxillary teeth when closed
or during excursive movements of the
mandible; when the teeth of the mandibular
arch come into contact with the teeth of the
maxillary arch in any functional relationship.
Types of Teeth
 The functions of teeth vary, depending on their
individual shape and size and their location in the
jaws. The three basic food processing functions of
the teeth are cutting, holding or grasping, and
grinding.
 Incisors are single-rooted teeth with a relatively
sharp thin edge referred to as the incisal edge.
Located in the front of the mouth, they are
designed to cut food without the application of
heavy forces. Central (front teeth) and lateral
(distal to the centrals) teeth are incisors.
 Canines, also known as cuspids, are located at
the corner of the arch. They are designed for
cutting and tearing foods, which require the
application of force.
 Premolars are a cross between canines and
molars. An older term for premolar is bicuspid.
The pointed cusps hold and grind the food. They
have a broader surface for chewing food. There
are two sets of premolars in the permanent
dentition and NO premolars in the primary
dentition.
 Molars are much larger than premolars.
The molars have more cusps than other
teeth that are used to chew or grind up food.
There are two sets of molars in the primary
dentition and three sets of molars in the
permanent dentition.
 In each quadrant there are five permanent
teeth (central, lateral, canine, & premolars)
that succeed or take the place of the five
primary teeth (central, lateral, canine, &
molars), they are called succedaneous
teeth. Three permanent molars do not
succeed primary teeth in each quadrant;
therefore they are nonsuccedaneous teeth.
Keywords
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Dentition
Occlusion
Maxilla - maxillary
Mandible –mandibular
Midline
Quadrant
Anterior
Posterior
Medial
Lateral (direction)
Permanent – adult
Oral cavity
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Incisor
Central
Lateral
Canine - cuspid
Premolar – bicuspid
Molar
Succedaneous
Eruption
Exfoliation
Primary – deciduous –
baby
 Vestibule