Dental Flashcards
Centric Relation aka
retruded contact position
CR is a relationship fo the bones of the upper and lower jaws ___ of tooth contact.
independent
Centric occlusion aka
intercuspal position
Centric occlusion is the relationship between?
mx and mn occlusal surfaces that provides the maximum intercuspation between the teeth.
Independent of condylar position; it is a “tooth guided” position.
Character of occlusal contacts in the unworn dental arch are:
point-to-point
point-to-area
edge-to-edge
edge-area
Bruxism may result in nonphysiological what contact?
area-to-area
four theoretical determinants needed to restore a complete and functional occlusal surface of a tooth are:
- amt of vertical overlap of the anterior teeth
- The contour of the articular eminence
- The amt and direction of lateral shift in the working side condyle
- The position of the tooth in the arch
Open bite aka
negative overbite
Underjet
mx teeth are lingual to mn. teeth
Curve of spee
Anteroposterior curvature of occlusal surfaces, beginning at the tip of the lower canine, following the buccal cusp tips of the premolars and molars and continuing to the anterior border of the ramus.
Curve of Wilson
Mediolateral curve that contacts the buccal and lingual cusp tips on each side of the arch.
Sphere of Monson or the Monson Curve is
Curve of Spee + Curve of Wilson
Mn functions as a class?
III Lever
In the oblique ridge:
MB cusp opposes
MB groove of the mn. first molar
In mx. oblique ridge: the DB cusp opposes
DB groove of mn. 1st molar
Class I
Mn first permanent molar is slightly anterior to the maxillary first molar.
Mx canine is btw. mn. canine and first premolar in normal canine relationship.
Class II Div I
Mx. arch is positioned mesially, with mx. 1st MB cusp btw. mn. 1st molar and 2nd PM.
Mx. canine is ant. to mn. canine.
Excessive anterior overjet.
Class II Div II
Mx arch positioned mesially, Mx 1st MB cusp btw mn. 1st molar and 2nd PM.
Mx. canine is ant. to mn. canine
Incisors have less anterior overjet but deeper vertical overbite than Class II Div. I.
Class III
Mn 1st molar is mesial to mx. 1st molar
Mx 1st MB cusp occluding distal to buccal groove of the Mn 1st molar.
Non-supporting cusps aka
balancing, guiding, shearing, or non-centric cusps
temporomandibular ligament aka lateral ligament
prevents posterior and inferior displacement of the condyle.
Main stabilizing ligament of the TMJ.
Spenomandibular ligament (attached to lingula) and Stylomandibular ligaments (attached to angle of the mandible)
Responsible for limitation of mandibular movements (limit excessive openings)
Collateral Ligaments aka discal ligaments
restrict movement of the disc away from the condyle during function. Composed of collagenous CT.
Two distinct motions in the joint?
rotation
translation
Lower compartment (condyle-articular disc) function
only a hinge-type or rotary motion can occur.
Upper compartment (mandibular fossa-articular disc) function
only sliding movements or translatory motion can occur.
The mn is moved in a number of planes:
- frontal plane
- horizontal plane
- sagittal plane
- up and down
- side to side
- forwards and backwards
Centric occlusion or intercuspal position is a what position?
tooth-guided
Rest position of the mn or postural position is a what position?
muscle-guided position
Centric relation or the retruded contact position–is a what position?
ligament-guided position
PDL have which fibers
principal fibers which are collagenous. They’re terminal portion are termed Sharpey’s fibers
Principal fibers are arranged in what 6 groups
transseptal fibers alveolar crest fibers horizontal fibers oblique fibers apical fibers interradicular fibers
transseptal fibers
keep teeth aligned
belong to gingiva because do not have osseous attachment.
alveolar crest fibers
prevent the extrusion of the tooth and resist lateral tooth movements.
oblique fibers
largest group in PDL
Bear the brunt of vertical masticatory stresses and tranform them into tension on the alveolar bone.
apical fibers
do not occur on incompletely formed roots
Cell types in PDL
fibroblasts-most common
cementoblasts
osteoblasts
non-keratinized oral tissue
buccal mucosa
soft palate
floor of mouth
junctional epithelium
Peridontium has 2 parts
Gingiva
Attachment apparatus
Attachment apparatus composed of:
PDL
Cementum
Alveolar process of the maxillae and mandible
Function of cementum
support for the fibers of PDL
Collagen type in reticular fibers
Type III
Collagen fibers in basal lamina
Type IV
Amt of collagen in a tissue is determined by
hydroxyproline
3 sources of blood supply to gingiva
supraperiosteal arterioles
vessels of PDL
Arterioles-emerge from crest
supraperiosteal arterioles
along facial and lingual surfaces of the alveolar bone,
vessels of PDL
extend into gingiva and anastomose with capillaries in the sulcus area.
Functional matrix theory
Soft tissue is the primary determinant of growth
Bone is responsive to soft tissue
Deglutition influences mandibular growth
The soft tissues of the brain expand thus pacing growth of the flat bones of the skull
Teratogen that causes cleft lip and palate
aspirin, valium, dilantin, cigarette smoke (hypoxia)
teratogen that causes microcephaly
x-radiation
teratogen that causes central mid-face discrepancy
ehtyl alcohol
teratogen that causes premature suture closure
Vitamin D excess
teratogen that causes microcephaly, hydrocephaly, microphthalmia
Cytomegalovirus, toxoplasma
teratogen that causes microphthalmia (1 eye smaller than other or both small), cataracts, deafness
Rubella virus
sulcular epithelium
thin, nonkeratinized stratifed squamous epi without rege pegs.
Lines gingival sulcus.
PDL function
Nutritive: contains a vascular network providing nutrients to its cells
Sensory: contains afferent nerve fibers responsible for pain, pressure, proprioception.
Support
Formative
Remodeling
Two types of nerves in PDL
- afferent or sensory, which is myelinated and transmits sensation.
- Autonomic sympathetic, which regulates the blood vessels
2 types of nerve endings in PDL
- free nerve endings; convey pain
2. encapsulated nerve endings; convey pressure.
Sheding of Primary Teeth
Max: 6-7-10-9-10
Mn: 6-7-9-9-10
Shedding of Permanent Teeth
Mx: 7-8-11-10 to 11-10 to 12-6-12-17(-21)
Mn: 6-7-9-10 to 12-11-6-11-17
Cells found in pulp
fibroblasts
odontoblasts
undifferentiated mesenchymal cells
Autonomic Nerve fibers
only sumpathtic autonomic fibers found in the pulp.
Unmyelinated fibers that travel to blood vessels
Afferent (Sensory) fibers
Predominately myelinated fibers
Form nerve plexus of Raschkow.
Pulp functions
nutritive
sensory
protective
dentinogenesis imperfecta
genetic disturbance of dentin formation
crown has opalescence (bluish-brown color)
Weak teeth, subject to attrition
Turner’s hypoplasia
individual teeth exhibit a disturbance of enamel maturation due to a developmental disturbance like trauma or infection.
Due to trauma.
periapical infection of primary predecessor can cause it.
Hutchinson’a teeth
sign of congenital syphillis.
Mottled enamel
aka dental fluorosis.
Temporomandibular ligament limits
amt of opening and retrusion of mn.
Initates downward motion of condyle
Flexion
bend in only the root of the tooth due to trauma. Less than 90 degrees, in apical 1/3/
Partial anodontia
aka hypodontia
2 missing teeth
