Tutorial 9 - Anatomy related to RPD construction Flashcards
LOs
Questions to consider during tutorial
ANATOMY RELATED TO RDP CONSTRUCTION
MAXILLA
- Labial + buccal sulcus
- thickness of palatine submucosa
ANATOMY RELATED TO RDP CONSTRUCTION
MANDIBLE
- sulcus
ANATOMY RELATED TO RDP CONSTRUCTION
lips
extra
ANATOMY RELATED TO RDP CONSTRUCTION
intraoral muscles
What muscles and anatomical structures lie at the periphery of correctly extended upper and lower partial dentures in a patient with only their canine teeth remaining?
UPPER
- alveolar ridge
- labial + buccal sulcus
- labial + buccal frenum
- maxillary tuberosities
- hamular notches
- palatine fovae
- vibrating line
LOWER
- alveolar ridge
- buccal, labial + lingual sulcus
- buccal shelves
- external oblique ridge
- mylohyoid ridge
- labial, buccal + lingual frenum
- pear-shaped pad (on removal of last molar, anterior to retromolar pad)
- retromolar pad
- retromylohyoid fossa
MUSCLES
- lips
- modiolus
- tongue
- cheek (buccinator)
- frenums
- mylohyoid
- masseter
- mentalis (lower lip muscle)
- pterygoid
1
What are the attachments of Mylohyoid muscle?
2
How does this influence base extension and impression recording when constructing partial dentures?
EXTRA - why can we not take the impression at rest?
1
- attachment is between the hyoid bone in the neck region + the mylohyoid ridge of the mandible
2
- under or over extending recording can lead to discomfort, pain, poor retention / stability of the denture
- need to ensure that denture is not extending to the mylohyoid ridge as this can be painful for the patient
EXTRA
- cannot take impression at rest as mylohyoid muscle would not be engaged
- hence must ask patient to protrude tongue to make floor of mouth come up
What anatomical features will influence your choice of major connector for the lower denture?
LINGUAL PLATE VS BAR
- bar is more hygienic
- bar needs minimum of 7mm between the gingival margin + lingual frenum/ highest part of floor of mouth
What anatomical structures may influence / prevent implant placement?
MAXILLARY
- maxillary sinus (antrum)
* iatrogenic sinus perforation is a
commonly encountered
complication when the selected
implant length is more than the
average bone height in the
posterior maxilla
* often need good implants
- incisive foramen
- nasal floor anteriorly
MANDIBULAR
- mental foramen
- ID canal/ nerve
Draw a diagram illustrating the correct extension of the distal saddle area of a lower partial denture for a patient missing all their molar and premolar teeth.
COMPLETE Q
How could you determine whether your special trays are overextended and encroaching on some of these oral muscles?
1
What problems may a palatal torus give when constructing an upper partial denture?
2
How may these problems be overcome when designing the denture?
1
- gets in the way of major connector
- hence rocking
- discomfort
2
what is support based on? (linked to next Q) EXTRA Q FROM ISOC DOC
What problems may occur as a result of the differences in support between the mucosa and the natural teeth?
How are these overcome?
1
- stress
- periodontal problems
- increase resorption due to stress
- occlusal trauma
- tilting of abutment tooth
- food packing
- pain + discomfort
