Autumn Final: Intro to Ortho Flashcards
whats the injury/dental diseases that can require ortho
incisor trauma, caries, periodontal disease
how does class III occlusion inmpact chewing
could not efficiently reduce particle size of food. no difference in number of chews but subjects had a difference in how they perceived they chewed
what are signs/symptoms with TMD
bruxism and clenching. positive predictive value 36^, negative predictive value 90%?
what findings about anterior open bite have been found w/ tmd
- studies found at least a week association with TMD
- most common association with anterior open bites are non working side interferences
what findings about over bite were found and tmd
no unfavorable things. significant association with DEEP bites and tmd (deep is excessive overlap)
what findings assoc with overjet and tmd
moderate correlation with excessive tmd overjet and TMD
what findings with respect to crossbite and tmd
-found unilateral or bilateral crossbite correlates with TMD
findings with respect to crowding and tmd
-mohlin et all; signifigant WEAK correlation between maxillary crowding and subjective symptoms of TMD
findings with respect to angle classification and tmd
bush et al; no correlation b/w angle classification and TMD class III subjects ruled out (insufficient sample size) -moderate correlation with Class III subjects and TMD
whats the relationship between overjet and trauma? caries and malocclusion? periodontitis and malocclusion?
- incisal trauma due to excessive OJ relationship is DEBATABLE
- caries + malocclusion WEAK evidence
- perio malocclusion WEAK evidence
what did angle think about occclusion
edward H angle; 1890s.
-believed upper first molar was key to occlusion! mesiobuccal cusp of upper first molar should SIT on the buccal groove of the lower first molar
from this he based three classifcations of malocclsuion :
1: mesiobuccal cusp of first molar fits in buccal groove of lower. upper canine occludes between lower canine and lower first premolar
2: mlower first molar is positioned distally to upper first molar. canine occludes mesial to contact between lower canine and lower first premolar
3: class III lower first molar is mesially positioned relative to upper first molar. canine occludes distal to contact between lower canine and lower first premolar
how is overjet measured and whats ideal measurement
measured from incisal edge of upper incisor to labial surface of lower incisor. Ideal is 2 mm
how is overbite measured?
from incisal edge of upper incisor to amount of coverage of the lower incisor
what type of movements are anterior teeth meant for
excursive movements; protrusion, lateral excursion. they disocclude posterior teeth during excursive movements, to protect them from sheer forces.
whats modern IDEAL occlusion aspects (6 keys to ideal occlusion)
- molar relationship; distal surfave of distobuccal cusp of upper first molar makes contact with mesial surface or mesiobuccal cusp of lower second molars. mesiobuccal cusp of upper first molar fits within groove between the mesial and middle cusps of lower first molar.
- crown angulation (mesiodistal tip) for all teeth except molars use the mid developmental ridge , for molars use the dominant vertical groove on the buccal surface .
- crown inclination (torque) ; anterior teeth have sufficient angulation to prevent over-eruption of anterior teeth and allow distal positioning of the contact points of upper teeth in their relationship to lower teeth. upper posterior teeth have lingual crown inclination which is constant from canines through second premolars and more pronounced in the molars. lower posterior lingual crown inclination in the lower posterior teeth progessively increased from canines through the second molars.
- rotations-none
- spaces ; all contacts tight
- occlusal plane; flat to a slight COS
