Study Cards 4 Flashcards
/1 to NB < 25
/1 recumbent
/1 to NB < 4mm
/1 retrusive
/1 to NB > 25
/1 procumbent
/1 to NB > 4mm CHECK THIS!!!
/1 retrusive
/1 to NB- what does it represent and what is the norm?
Axial relationship of mandibular incisor, 25 degrees
/1 to NB- what does it represent? What is the norm?
Antero-posterior position of the mandibular incisor (norm 4mm)
1 / to NA represents? What is the norm?
Antero-posterior position of the maxillary incisor (4mm is norm)
1/ to NA < 22 degrees
1/ recumbent
1/ to NA < 4mm
1/ retrusive
1 /to NA > 22
1 / procumbent
1 /to NA > 4mm
1 /protrusive
1 /to NA angle- what does it represent?What is the norm?
Axial relationship of maxillary incisor (norm is 22 degrees)
1/1 axial relationship < 131
incisor recumbency
1/1 axial relationship > 131
incisor procumbency
ANB > 2 or < 2
Dental base discrepancy
All growth in the mandible occurs where?
Posterior to the second molar
Anterior crossbite (single tooth) in the permanent dentition- how to treat?
Fixed or removeable appliance,
Be aware of potential funcitonal shift
Defer periodontal surgery until crossbite corrected
Anterior displacement without reduction- what treatment?
What do you usually see clinically?
ROM typically limited
Symptomalogy dictates treatment- Repositioning splint, may require surgery, patients frequently able to function without reduction
Around what structure is palatal closure oriented?
At incisive foramen- secondary palate zips closed from anterior to posterior, primare palate zips closed from posterior to anterior
At what rate do premolars erupt through bone?
about 1 mm every 4-5 months
Branchial grooves (cleft-outer surface) gives rise to?
External auditory meatus, cervical sinus
Can ectopically erupting permanent canines be prevented?
How would one do this?
Can potentially be prevented.
Extract primary canines (and first molars)
If Class II molar relationship, consider headgear therapy early.
Cartilagenous growth theory?
Theory that cartilagenous growth is the primary determinant of craniofacial growth
Nasal septum theory of craniofacial growth- Latham
Septomaxillary ligament
Computer forecasts of growth vs. average changes?
In studies it has been shown that there is no significant difference in accuracy
Cranial vault forms by what mode of bone formation?
Intramembraneous
Cranium vs. Maxilla vs. Mandible in terms of completion of growth?
Follows a gradient- cranium grows first, mandible grows last.
Development definition
increase in complexity- fertilized egg to embryo
Diagnosis of maxillary frenum that may need removal?
Stretch frenum and look for gingival blanching or displacement.
Different areas of the face tend to do what with respect to groth?
Grow at different times and rates
Distal step kids always become
Class II
Do third molars cause crowding?
No difference in studies with patients that have vs. do not have 3rds
Does stress increase or decrease bone density?
Increases- bone formation favored
Enamel defects associated with alveolar clefting can have what effect?
Increase in caries
Extraction therapy and TMD?
Extraction therapy and ortho?
No well controlled studies that demonstrate relationship
TMD may occur coincidently with treatment but usually not because of treatment
Facial form and pattern tends to do what? What does this mean for a class II patient?
maintain itself; class 2 features will be maintained or become exaggerated as time goes on.
First branchial arch anomalies represent what percentage of branchial anomalies?
1%
Flush terminal plane can become
Class I or II
Functional appliances- do they truly promote mandibular growth
Probably not- most of the correction is predominated by tooth movement, overall tx is dentoalveolar, No differences in mandibular growth but might cause remodeling of glenoid fossa
Functional matrix theory?
Functional demands of the craniofacial complex control growth- moss and salentijn)
GoGn-SN < 32
Hypodivergent
GoGn-SN > 32
Hyperdivergent
Growth definition
increase in size
Growth is made up of
hyperplasia- increase in number of cells resulting from mitotic divisions
hypertrophy- increase in size of individual cells
accretion- increase in amount of non-cellular material
Headgear- do you get orthopedic or orthodontic effects?
Typically orthodontic effects and not orthopedic
Heirarchy of evidence- what is the best evidence?
Systemic Reviews and Meta-analysis, followed by Randomized Controlled Double Blind Studies
How can you get a non-vital tooth from ortho?
Pressure and/or intrusion compromises blood flow- previous trauma may predispose pulp to loss of vitality
How do you do a serial extraction?
Extract primary canines
Extract 1st primary molars when premolars have 1/2 root development- encourages mandibular premolar to erupt ahead of canine
Extract 1st premolars (allows for spontaneous distalization of canine during eruption)
How do you regain space in each arch?
Maxilla- distalization- headgear, fixed appliances, removable appliances
Mandible- molar uprighting- Fixed appliances, removable appliances
How does a lateral ceph aid in the diagnosis of a malocclusion? (4)
Skeletal relationship
Dental to skeletal relationship
Denture to denture relationship
Soft tissue relationship
How does facial growth relate to somatic growth?
typicall tend to correspond
How much force is needed to produce bodily movement?
100gm, which is double that needed for tipping forces.
How much space loss do you get immediately when primary first molars are lost prematurely?
Mandible- 1.5mm of space loss per side
Maxilla- 1mm space loss per side
How much wear is required with a mandibular chin cup?
How common is relapse?
Are the results clear cut?
Long term wear needed, more than 3 years at 11-12 hours a day
Very common to relapse
Conflicting results as to restraint of mandibular growth
Hyperdivergent facial types tend to have what kind of sensitivity? What does this mean in terms of extractions?What does it mean for therapy? What sohuld vectors encourage?
Open bite sensitivity, typically favors extraction
Avoid posterior extrusive force
Encourage posterior intrusive forces
Hypodivergent has what kind of bite and what does this mean in terms of extractions?
What does this mean in ortho therapy?
What should be encouraged?
Deep bite typically favors non-extraction
Therapy- encouraging posterior extrusive force
Encourage anterior intrusive force vectors
Ideal lip closure?
Should be competent without muscle strain
If mesial step is greater than 2mm, then
Class III can occur in about 20% of cases.
n normal swallowing how much facial muscle participation?
What does this mean in terms of the dentition?
Normal swallowing has no facial muscle participation;
May contribute to or maintain an anterior open bite; relapse rates are high
In the predentate infant, the gum pad relationship reflects what?
What does lack of alveolar development mean?
What kind of profile in predentate infant?
Reflects normal maxillary/mandibular relationship;
Decreased vertical dimension and shallow palatal vault;
Retrognathic profile is normal
In what direction does the face tend to grow?
Downward and forward
Indications for extraction of third molars?
Chronic pathology
External root resorption
Pericoronitis
Caries
Is TMJ disk displacement a congenital condition?
No
Is there any evidence of a relationship between dental caries, periodontal dz, TMD, or dental trauma and orthodontic treatment?
No, no relationship. There are some studies that support a positive impact with trauma, but no conclusive evidence.
Mesial step can become
Class I (80 percent) Class II (about 19 percent) Class III (about 1 percent)
Norm for nasolabial angle?
100-110 degrees
Occlusal plane < 14
Hypodivergent
Occlusal plane > 14
Hyperdivergent
Occlusal plane-SN- what is it similar to? What is the norm?
Similar to mandibular plane (norm 14 degrees)
Pg/1 to NB represents? What is the norm?
Profile balance- norm is PG/1 equals /1 to NB
Pg/1 to NB: equal
Lac of balance between Pg and /1
Prediction of crowding based on primary dentition?
When primary dentition is crowded, permanent dentition will be crowded.
The more spacing in the primary dentition, the less crowding generally in the permanent dentition.
Premature loss of primary tooth can result in delayed eruption when?
Prior to the development of 1/3 to 1/2 of the root of the permanent tooth
Prevalence of cleft palate alone? What racial ethnic group? What gender? Familial pattern?
1:2000, asians slightly higher, females slightly higher, 10% familial cases
