Summary oral anatomy

ORAL ANATOMY




BASIC ORAL ANATOMY


 Oral Cavity (mouth)


 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


3. The term dentition is used to describe the natural teeth in the

jawbones.


4. Primary dentition is the frst set of 20 primary teeth. Also referred

to as “baby teeth” or “deciduous teeth”


5. Permanent dentition refers to the 32 secondary or “adult” teeth.


6. Mixed dentition occurs when both primary and permanent teeth are

present, usually between the ages of 6 to 12.

,Dental arches


7. The maxillary arch (upper arch), actually part of the skull, is fied

and not capable of movement. The teeth in the upper arch are set in

the maiilla, the maiillary bone.


8. 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


 An imaginary midline divides each arch into a left half and a right half.

When the maiillary and mandibular arches are each divided into

halves the resulting four sections are called quadrants, as follows:


1. Maiillary right quadrant


2. Maiillary left quadrant


3. Mandibular right quadrant


4. 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 & Eifoliation


 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 maiillary teeth

when closed or during eicursive movements of the mandible; when

the teeth of the mandibular arch come into contact with the teeth of

the maiillary 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 fve permanent teeth (central, lateral,

canine, & premolars) that succeed or take the place of the fve 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.