Complete Dentures Flashcards
What are the Angles classifications of malocclusion?
Class I
Class II
Class II division 1
Class II division 2
Class III
What is the molar relationship in a normal class 1 relationship?
the mesiobuccal cusp of the maxillary first molar aligns with the buccal groove of the mandibular first molar
What is the canine relationship in a normal class 1 relationship?
the maxillary canine occludes with the distal half of the mandibular canine and the mesial half of the mandibular premolar
The mesial incline of the maxillary canine occludes with the distal incline of the mandibular canine
The distal inclinde of the maxillary canine occludes with the mesial incline of the mandibular premolar
What is a normal line of occlusion?
normal smooth curves
normal overbite
matching midlines on both arches
What is a class II occlusion?
this is when the distobuccal cusp of the maxillary first molar falls on the mesio-buccal grrove of the mandibular first molar
What does class II div 1 indicate?
that the upper incisors are proclined
What does class II div 2 indicate?
the upper lateral overlap the centrals and the centrals are retroclined
Describe the facial profile of an individual with a class II occlusion. What is the cause of this?
convex face shape
mandible that is too small or maxilla that is too large
What is an overjet?
it is the horizontal overlap of the maxillary central incisors over the mandibular central incisors.
how much of the upper front teeth protrude forward in relation to the lower front teeth
What is an overbite?
this is the vertical overlap of the maxillary central incisors over the mandibular central incisors
how much of the front teeth cover the lower front teeth in a vertical dimension
How can you measure overbite?
can be measured using a probe vertically
(how much of the lower teeth can you see)
What is considered to be a normal overbite?
2-3mm
How can you resolve an overjet that is too great to be fixed by manipulation of the tooth setting in dentures?
advised to remove the mandibular first premolar
in very extreme cases remove both premolars
What is the cause of class III malocclusions?
generally due to an excessively large mandibular arch or smaller maxillary arch
Describe the facial profile of an individual with a class III malocclusion
concave face profile
What are some problems associated with class III cases?
- wider lower arch can lead to problems selecting teeth size/mould- using the same mould on both arches can lead to significant spacing therefore compromising the aesthetic
- crest of the lower arch can be located further buccally than the upper which can lead to difficulties obtaining adequate occlusal relationship between 2 arches
What modifications can we make when setting up for class III complete dentures?
- set the teeth edge to edge, no overbite or overjet
- inclining the anterior mandibular teeth lingually without encroaching the tongue space
- setting up the upper teeth slightly proclined without making unstable when anterior load is applied
How should the maxillary central incisors be set in the occlusal rim?
the incisal edge of the central should be set on the level of the occlusal rim
How should the maxillary lateral incisors be set on the occlusal rim?
the incisal edge of the lateral should be approximately 1mm higher than the central and the tip of the canine
How should the maxillary canines be set on the occlusal rims?
the incisal edge of the canine should be at the same level as the central incisor
How should the lower centrals be set on the occlusal rims?
- set 90 degrees to the occlusal plane
- incisal edge should form 1-2mm horizontal and vertical overlap with upper centrals
How should the lower lateral incisors be set on the occlusal rims?
set at the same height as the centrals with the long axis slightly inclined
How should the lower canines be set on the occlusal rims?
long axis should be slightly inclined almost 90
should be set prominent with height 2mm above the occlusal plane
What is the curve of sphee ?
curvature which begins at the tip of the canines and follows the buccal cusp of tips of the premolars and molars when viewed from the side
What is the curve of wilson and sphere of monson?
medio-lateral curvature of the occlusal plane of the posterior teeth
the purpose of this arch is to complement the paths of the condyles during movement o fthe mandible
How should you choose your occlusal schemes for your dentures?
they should be based on previous occlusal methods and ridge form
(ridge form classifications Howell and Cawood classifications)
What occlusal scheme would you choose for a patient with well formed ridges (Howell and cawood class III)?
more anatomical teeth
What kind of occlusal scheme would you consider for someone with flatter ridges?
lower cusp height
What is a balanced occlusion?
bilateral, simultaneous, anterior and posterior occlusal contact of teeth in centric and eccentric positions.
balanced occlusion in complete dentures us unique and does not occur naturally (in natural teeth)
therefore, there are 3 points of contact regardless of the mandibular position
What is centric occlusion?
occlusion of the teeth when the mandible is in centric relation
What is centric relation?
- this is when the condyles articulate in a posterior superior position againts the posterior clope of the articular eminence
What is lingualised occlusion?
- the maxillary palatal cusps contact against the central fossa of the mandibular teeth
- buccal cusps of the madibular teeth do not contact the opposing maxillary teeth
- mandibular teeth are lingual to the alveolar ridge
What are the advantages of a lingualised occlusion ?
- aesthetically pleasing
- provides efficient mastication
- less destruction to alveolar bone- less cusps= less chance the denture gets moved by side shift
- reduced number of occlusal contact easier to set up
- vertical forces are directed more centrally to the mandubular ridge creating less tilting, giving the denture more stability
What is monoplane occlusion?
this concept assumes that the anterior posterior plane is parallel to the residual ridge
plane of occlusion is completely flat and level
No curve of spee or monson (no compensating curves) incorporated into set up
no vertical overlap of anterior teeth
very slight disocclusion in protrusion (balancing ramps)
What is a patient instructed to do when using monoplane occlusion?
they are instructed not to incise the bolus
What is an advantage of monoplane occlusion?
- does not allow lateral locking of teeth, allows freedom of movement
Monoplane occlusion is ideal for…
flat or atropic ridges
