Tooth Alignment & Occlusion Flashcards
Describe ideal occlusion
all the teeth in the maxillary arch are in contact with all the teeth of the mandibular arch
What is malocclusion?
deviation from the ideal; abnormal occlusion
Skeletal classification
relationship of the bone of the maxilla to the bone of the mandible
class I, class II, class III
Describe class I occlusion
normal, “ideal” relationship of maxilla to mandible
The profile of class I occlusion is called…
mesognathic or orthognatic
Describe class II occlusion
mandible is retruded (pushed back), mandible distal to maxilla
The profile of class II occlusion is called…
retrognathic
Describe class III occlusion
mandible is protruded (pushed forward)
The profile of class III occlusion is called…
prognathic
Dental classification (E.H. Angle)
relationship of the teeth of the mandibular to the teeth of the maxilla, particularly 1st molars and canines
class I, class II, class III
True or False: Occlusion classification can be bilateral or unilateral
True
Class I dental classification is ______ (*hint: end in -occlusion)
neutrocclusion *ideal relationship
Describe the molar relationship of Angles Class I
mesiobuccal cusp of permanent maxillary 1st molar is directly in line with mesiobuccal groove of mandibular 1st molar
Describe the canine relationship of Angles Class I
permanent maxillary canine fits into facial embrasure between mandibular canine and 1st premolar
Class II dental classification is _______.
distocclusion
Describe the molar relationship of Angles class II
mesiobuccal cusp of maxillary 1st molar is anterior to mesiobuccal groove of mandibular 1st molar by AT LEAST the width of a premolar
Describe the canine relationship of Angles Class II
maxillary canine anterior to facial embrasure of mandibular canine and 1st premolar by AT LEAST the width of a premolar
Less than the width of a premolar is a ________ to Class II.
tendency
*same concept for Class III
Describe Division I of Class II
maxillary central incisors slightly protruded
Describe Division II of Class II
maxillary central incisors retruded, inclined lingually
-laterals often slightly overlap centrals
What clinical findings may be present in Class II (distocclusion)
-overjet
-severe/deep overbite
-crowded maxillary anterior teeth
Class III dental classification is ________.
mesiocclusion
Describe the molar relationship of Angles Class III
mesiobuccal cusp of maxillary 1st molar is distal to mesiobuccal groove of mandibular 1st molar by at least the width of a premolar
Describe the canine relationship of Angles Class III
maxillary canine is distal to facial embrasure of mandibular canine and 1st premolar by at least the width of a premolar
What clinical findings may be present in Class III (mesiocclusion)
-anterior crossbite
-edge to edge
-mandibular incisors crowding
-mandibular incisors lingually tipped
List the factors influencing occlusion
-arrangement of teeth in the arch
-relationship of mandibular arch to maxillary arch
-relationship of the mandible to the maxilla
-Temporomandibular joint (TMJ) and its parts
-muscles, nerves, ligaments, and soft tissues affecting position of mandible
-abnormalities that may be detrimental to dental health
What is labioversion/labial version malocclusion
tooth is out of alignment to the labial or buccal compared to the arch or other teeth
*malocclusion of individual teeth
What is buccoversion/buccal version malocclusion
posterior tooth out of alignment compared to the arch or other teeth
*malocclusion of individual teeth
What is lingoversion/lingual version malocclusion
tooth is out of alignment to the lingual compared to the arch or other teeth
*malocclusion of individual teeth
What is toroversion malocclusion
tooth is rotated
*malocclusion of individual teeth
What is supraeruption/extrusion malocclusion
tooth that is over erupted and is abnormally long compared to the rest of the occlusal surface
*malocclusion of individual teeth
What is infraocclusion/infraversion malocclusion
tooth is abnormally short compared to the rest of the occlusal surface
*malocclusion of individual teeth
What is an anterior crossbite
maxillary incisors or canine are lingual to mandibular incisors or canines
*malocclusion of groups of teeth
What is a posterior crossbite
maxillary posterior teeth are more lingual to mandibular teeth, maxillary lingual cusps are not in fossae of mandibular teeth
*malocclusion of groups of teeth
Describe edge to edge malocclusion
incisal edge of maxillary anterior teeth occlude with the incisal edge of mandibular teeth
*malocclusion of groups of teeth
Describe open bite malocclusion
mandibular teeth do not touch maxillary teeth, no vertical overlap
-can be caused by thumb sucking or tongue thrusting
*malocclusion of groups of teeth
Describe overjet with HORIZONTAL overlap
amount of facial horizontal overlap between maxillary anterior teeth to the mandibular teeth
-normal is 2-3mm measured w/ probe
*malocclusion of groups of teeth
Describe overjet with VERTICAL overlap
extension of the incisal edge of maxillary anterior teeth below the incisal edges of mandibular anterior teeth
Normal/slight overbite
overlap occurs within incisal 1/3rd of mandibular anterior teeth
Moderate overbite
overlap occurs in the middle 1/3rd of mandibular anterior teeth
Severe/deep overbite
overlap into the cervical 1/3rd of mandibular anterior teeth
*possibly can see bite marks in palate with severe overbite
What is the resting vertical dimension
at rest, with lips together, teeth should 1-2mm apart
What is centric occlusion
relationship of maxillary and mandibular occlusal surfaces when teeth are in maximum contact, or intercupsation (fitting together the surfaces of the opposing teeth)
Describe centric relation
relation of upper and lower jaw, where head of the condyle in the most posterior-superior position in the glenoid (mandible) fossa
-when jaw is back as far as it can go this can be seen when swallowing
What is functional/dynamic occlusion
refers to the tooth contacts while the mandible is in action (moving)
Intercuspation
buccal cusps of the mandibular teeth are interlocked between buccal and lingual cusps of maxillary teeth
Mandibular teeth tip ______.
lingually
Maxillary teeth tip ______.
facially
Anterior teeth tip slightly _______.
forward
Lateral excursion
mandible moves to the left and right
Working side
side toward which the mandible moves, maxillary and mandibular cusps touch
Balancing side
non functional side, teeth do not contact
Canine guidance or rise
mandible canine opens the bite by gliding down the lingual surface of the maxillary canine
Group function
premolars occlude during lateral excursion, premolars should only assist while canines take the brunt of the occlusion
Protrusion
mandible moves forward, only the 4 anterior touch, but may include the canines, posterior teeth do not contact
Open contacts
sites where interproximal space exists because proximal crests do not meet
*not the same as diastema
List the reasons for open contacts
-developmental disturbances
-missing teeth
-oral habits
-dental disease
-overdeveloped frena
-faulty dentistry
Curve of Wilson
transverse occlusal curve, side to side, mandibular teeth concave since they tilt lingually
Curve of Spree
from the lateral view (usually from buccal aspect) when teeth are in centric occlusion, cusp tips of posterior teeth conform to a fairly even curve in an anterior to posterior direction
-mandibular teeth curve is concave, maxillary teeth curve is convex
Primary occlusal trauma
excessive force with normal bone support
Secondary occlusal trauma
excessive force with bone loss and inadequate bone support
List the causes of occlusal trauma
-premature contact
-only a few teeth in contact (unequal pressure)
-initial contacts on inclined planes of cusps (unequal pressure)
-heavy forces in lateral or horizontal direction
-increased frequency, intensity, or duration of contacts (bruxism, clenching)
What are the clinical findings of occlusal trauma
-tooth mobility
-fremitus: vibration
-tooth sensitivity
-wear facets
-open contacts
-TMJ disorders
What are the radiographic findings of occlusion trauma
-widened periodontal ligament (PDL)
-thickened lamina dura (thin covering of alveolar bone seen radiographically)
-angular/vertical bone loss
-root resorption
-furcation involvement
True or false: occlusal trauma causes periodontal disease even with no presence of bacteria
FALSE: occlusal trauma causes periodontal disease ONLY in the presence of bacteria
