Important Numbers Flashcards
Limited opening is…
below 27 mm (23 mm is example given)
Maximum opening is…
the distance between incisal edges + overbite
Maximum opening in adolescents and adults is… and lateral excursive is…
50 mm vertical opening and 12 mm lateral exursive
Most Cranium growth is completed by age…
5
Anterior Cranial base growth is completed by age…
7
At what age can you begin to superimpose lateral cephalograms?
Age 7
The anterior cranial base stops growing and becomes stable for use in superimposition at…
7 years
Neural Growth is completed at age…
6-7
Most rapid Somatic growth occurs at…
Birth to 2 years OR before birth OR conception to birth
How much will an 11 yo male’s mandibular molars erupt in a 2 year period?
1.5 mm
How much will an 11 yo male’s lower face height increase per year?
1mm/year
The maximum width of the skull is achieved at age…
7-8
The human eye can differentiate… shades of gray
16
Digital photography uses …-bit which gives… shades of gray
8-bit; 256 shades of gray
Gemination
1 root, 1 pulp > fused crown
Fusion
2 roots, 2 pulps > fused crown
Hypodontia
missing 1-5 teeth
Oligodontia
missing 6 teeth or more
If a patient is missing 3rd molars there is a…% changes of missing lower 5’s, …% chance of missing U2 and a …x chance to be missing other teeth.
3.4% missing lower 5’s
2.2% missing U2
13x chance to be missing other teeth
*no incremental likelihood of supernumerary or peg laterals
Genes responsible for tooth agenesis
MSX1 & PAX9
When do primary teeth start to calcify in the fetus?
14 weeks (upper and lower central incisors)
Mineralization of what teeth begins at birth?
Permanent first molars
At birth, which tooth as completed crown calcification?
Mandibular Incisors
The calcification of the upper and lower third molars…
varies greatly
Fusion of the Mandibular Symphysis occurs…
Shortly after birth; 3 months after birth; within the first year
How long should an extruded tooth be retained for stability?
6 months
Fraction of root formation when tooth begins eruptive movement
2/3rds
Fraction of root formation upon tooth emergence into oral cavity
3/4ths
how long does it take for completion of root formation after tooth eruption
2-3 years
What is the minimum number of lobes required to form a tooth?
4
The peak incidence of dental trauma occurs at what age?
8-10 yo
What is the compression rate for adult and child CPR
100 per minute
What is the adult CPR sequence?
30 compression & 2 breaths
How many minutes can the brain survive without oxygen?
6 minutes
For adult CPR a breath is given every …
5 seconds
The proper wavelength for curing/optimal wavelength for Camphorquinone is …
460-480 nm
The appropriate concentration of Sodium Fluoride in mouthwash for orthodontic patient is ..
0.05%
Tongue formation begins at week … in utero.
4
The tongue reaches its maximum size at age …
8
The primary palate is formed by the … week in utero
6th, 6-8 weeks
Secondary palatal closure in the fetus begins at week … and is completed by week …
10
12
At what time during fetal development does cleft lip/palate occur?
6-8 weeks
Cleft Palate develops during the … trimester of pregnancy
1st
Cleft Palate incidence is …
1 in 750 births (worldwide)
The most effective time to close a cleft palate surgically is …
one year after birth
In a cleft plate patient when is the appropriate time for alveolar grafting?
when the canine root is 2/3rds formed (to start eruptive process)
When is the best time for NAM treatment?
within 3 months after birth
Most developmental anomalies occur:
Embryonic (5-10 weeks) stage
Fetal Alcohol Syndrome occurs by … in utero
day 17
Downs Syndrome prevalence is …
1 in 800 births
… mg of folic acid reduces the chance of cleft lip/palate by …
0.4 mg
33%
Most neurons in fetus at …
10 weeks after conception
Most synapses in infant at …
2-3 years
Fusion of the intersphenoidal suture occurs …
at birth, shortly after birth, 3 months after birth
Fusion of Spheno-Ethoidal suture occurs at …
7 years
Fusion of Spheno-Occipital sutures occurs at …
15-16 years, 15-20 years
Ossification of Sesamoid bone in hand-wrist film means …
1 year before maximum growth spurt (30% growth completed); 60-70% of growth remaining (SMI:4)
Peak height velocity occurs at age … in girls and age … in boys
12 girls
14 boys
Peak Height velocity happens from puberty for up to … months after
24 months
In normal girls, Peak Height velocity occurs … months before menarche
18-24
In late-maturing (late menarche) girls, peak height velocity occurs … months before menarche
6-11
Peak Height Velocity is measure in …
cm or inches PER year (it is a rate)
A Physician is concerned if a child’s growth is above the … percentile
95th
More radiation:
Tech 99 > CT
Increase in mandibular intercanine width from primary to permanent dentition is …
2 mm, “slight increase”
Primary to permanent arch length change is …
slight decrease
The greatest amount of mandibular arch length from the mesial of the molars is at age …
6
The greatest loss of arch length occurs at the … at age …
Maxillary second primary molar at age 6.5
Minimum total filtration required by a machine that operates in excess of 70 kvp is …
2.5 mm of aluminum (or the equivalent of that)
How long is x-ray film in the fixer?
10 minutes
The AAO standard for facial photo size is …
1/4th of life size
X-ray operators should not not exceed … Roentgens per week
0.1 Roentgens (100 milli Roentgens)
The absorbed does of radiation is …
Grays, microGray
The effective and equivalent doses of radiation is …
Sievert, microSievert
What radiation does accounts for organs be irradiated?
Effective dose
The range of normal Mandibular Plane angle is … degrees
27-37
The difference between SN and Frankfort Horizontal is …
7 degrees
Incisor angulation to arch length ratio is …
10:8
10 degrees of retroclination requires 8 mm of space (ie extraction)
The normal range for the Nasolabial angle is …
94-110 degrees
The ideal percentage of lower facial height is …%
55%
In a 16 yo female, the ratio of upper to lower facial height is …%
43:57
N-ANS is what percentage of N-Me?
45%
Lower face height is slightly over … of total face height
over half (55-57%)
The Hyoid is derived from which brachial arch?
2 (body) and 3 (greater wings)
In the craniofacial complex there are … cranial, … facial and … total bones
8 Cranial
14 Facial
22 total
There are … cartilages in the inferior 1/3rd of the nose
3
Most nasal septum deviations occur in the … of the nose
inferior 1/3rd
The Hyoid bone is located between … and …
C3 and C4
The widest cervical vertebrae from C1 to C5 is …
C1 (atlas)
Condyle width to AP lengh
Twice as wide
The distance from the CEJ to the alveolar crest is …
2 mm
To prevent black triangles the maximum distance from contact to Alveolar crest is …
5 mm
The Facial nerve has … branches and they are …
5 Temporal branch. Zygomatic branch. Buccal branch. Marginal mandibular branch. Cervical branch
The normal incubation period for Hep b and C is …
1-6 months
For antibacterial prophylaxis Clindamycin should be given to the patient … prior
1 hour
Which molecules activate Aracadonic Acid Pathway/Prostaglandin production?
IL-1, IL-6, TNF alpha, BMP (*NOT neocytokines)
What antibiotic should be used to treat patient who is allergic to Penicillin with a history of Rheumatic Fever?
Erythromycin
Concerning dental classification the best to worst chewing efficiency is …
Cl 1 > Cl 2 > Cl 3
Pain due to heavy pressure occurs after …
3-5 seconds
An acceptable CO/CR shift is … mm but not a … shift
1 mm but not a lateral shift
If a 2-3 mm posterior CO/CR shift exists at the completion of treatment a occlusal equalibration should be completed in the following manner ..
Grind mesial incline of upper and distal incline of lower
TMJ sounds are a common finding in ..% of the population
25%
Significant decalcification occurs in …% of patients
50%
Avoid fluoride for …months to allow WSL to heal and remineralize
2-3 months
Tatar control toothpaste reduced supragingival calculus by …% due to …
50% due to pyrophyosphate
The first meeting of the AAO occurred in … in …
1900, St. Louis
“A-A-O the first meeting Nineteen-O-O”
The first meeting of the ABO occured in … in …
1929 in Estes Park, Colorado
… % of openbites self-correct
80%
…% of openbites are treated
20% (opposite of the 80% of openbites that self-correct)
The incidence of open bite … following puberty
decreases (80% self correct)
Post extraction treatment, a study by Little found what fraction of mandibular incisor crowding relapse?
2/3rds
The normal adolescent intermolar width is …mm
33-35 mm
The normal adult intermolar width is …mm
36-39 mm
The normal Bolton ratio 6-6 aka mesial 7 to mesial of 7 is …
91%
Complete nasal obstruction leads to a … degree change in head posture
5 degree
The lower third of the face is divided into:
1/3 upper lip
2/3 lower lip and chin
Invisialign can correct …mm of anterior open bite (AOB)
2mm
The limit of arch length discrepancy to be treated with a non-extraction modality is …mm
4mm (greater the 4mm, extraction)
The swallowing force with teeth in contact is …g
100
What the indications for Serial Extraction?
Cl I molar, moderate OB/OJ, severe crowding of 10 mm or more
The appropriate force on a TAD is …g
100-200
A power chain loses …% of elasticity/force in the first day
50%
When etching for 15 seconds … micron loss
8-10 micron
37% phosphoric acid etch for 30 seconds results in a … micron loss
2-10
… is used to etch ceramic crowns for bonding
9% HF acid
In a patient with a nickel allergy … wires should be used
TMA (contains no nickel)
A SS archwire contains …% Chromium and …% Nickel
18% Chromium
8% Nickel
In a SS AW Chromium adds the following property
prevents corrosion
In a SS AW Nickel adds the following property…
adds flexibility (think NiTi)
If the AW length is doubled the strength/force is …, Springiness is … and Range is …
strength/force is 1/2
Springiness is 8x
Range is 4x
Lip bumper expansion, …% is accomplished in the first 100 days, then …% in the next 100 and …% in the last 100
50%
40%
10%
If the distance between two magnets is halved the force increases …%
400%
The magnetic force equation is…
1/r² , where r is the distance b/w the magnets
Phase I Class 2 correction has a …% success rate
75%
Twin block therapy results in …% skeletal correction
55%
A … order bend is used for pure rotation
1st order bend
The duration threshold of light force to produce tooth movement is … hours a day
4-6 hours a day
In physiologic response to sustained pressure, tooth movement begins after … hours of force application
48 hours
The range for normal eruptive force of a tooth is …
2-10 grams
The optimum canine retraction force range is …
100-150 grams
The force needed to intrude mandibular central incisors in …
20 grams
The average force needed to intrude a Maxillary incisor is …
25 grams
The order of two jaw surgery is …
Mx fracture, Mx fixation, BSSO, intermaxillary fixation , then Mn fixation
A orthognathic surgery is considered highly stable if there is …% of significant post tx change
10%
A orthognathic surgery is considered stable if there is less than …% of significant post tx change
less than 20%
Rigid internal fixation is not needed for all surgery just …
combo (2 jaws)
In advancement genioplasty, the ratio of hard and soft tissue advancement is …
1:1
Of patients with gingival inflammation, …% have no progression of perio disease, …% have mild progression, and …% have rapid progression
10% no progression
80% mild
10% rapid
A patient with congenitally missing U2 should be handled in the following manner…
Extract B and let U3 errupt, then distalize to create space, only 1% loss in 4 years
The incidence of maxillary impacted canines is …%
1-2%
The incidence of bilateral maxillary impacted canines is …%
8%
Impacted canines are found palatal …
2/3
Impacted canines are found facial
1/3
Impacted canines are more common in male or females?
2x more common in females
…% of impacted canines distal to the middle of the lateral incisor will self correct
91%
…% of impacted canines mesial to the middle of the lateral incisor will self correct
64%
The minimum ossteointregration necessary for implant success is …%
5%
When 300 grams of force is applied for 3 months to titanium implants in animal studies, the …% are sucessful
94%
Estimated implant healing time in the mandible is … months
and the maxilla is …months
Md 4-6 months
Mx 6-8 months
Implants require …mm space
7mm
When placing an implant head of fixture should be …mm far apical to the desired gingival margin
4mm
The best time for implant placement is …
after growth has ceased
A serial Ceph confirms growth has ceased after …months without growth
6 months (ok but 12 months better)
The prevalence of Class II malocclusion in the US and Norther Europeans is …%
15-20%
…% of Class II patients are due to retrognathic mandible
75%
An Adenoidectomy has a …% success rate in correcting open mouth breathing
80%
…% of non-ectopic third molars erupt normally
33%
The normal oral temperature range is …
35-37 Degrees C
Plus/Minus 1 Standard Deviation is …% of the sample
66-68%
Plus/Minus 2 Standard Deviation is …% of the sample
96%
Plus/Minus 3 Standard Deviation is …% of the sample
99.7%
For a cephalometric study must have at least … patients
15
Of the class two correctors …. steepen the occlusal plane and … control the mandibular plane angle
Herbst and Mara steepen the occlusal plane
Twin block control Mn plane angle
Of the class II correctors the … demonstrates decreased overbite and overjet
Herbst
Of the class II correctors the … does not change MP angle that much
Herbst
It is appropriate to use the Twin Block in the …
late mixed dentition
When replacing a lateral incisor with an implant, …% of the width of the central incisor is needed
66%
N-ANS is …% of N-Me
45%
The posterior to anterior face height ratio is …
40:60
