exam2 Flashcards
Treacher Collins is caused by
diminished neural crest cell migration.
occurs at 7th week of intrauterine life.. genetic origin
disturbance in 1st brachial arch
FAS
fetal alcohol syndrome
germ layer formation & initial organization of structures
germ layer formation & Initial organization begins on what day
Day 17
crouzon Syndrome
prenatal fusion of the superior and posterior sutures of the maxilla along the wall of the orbit.
Produces distortion of cranial vault
Pierre Robin Syndrome
A fetus head is flexed tightly again
respiratory problems at birth that may require
some children have
Hemifacial Microsomia primary cause
Early loss of neural crest cell
6 weeks after conception
Treacher Collins characterized by
generalized lack of mesenchymal tissue in lateral part of face
Underdevelopment of maxilla& mandible
Absence of malar bone
intrauterine molding
refers to pressure against the developing face prenatally.
can lead to distortions in rapidly growing face.
Torticollis
a twisting of the head caused by excessive tonic contraction of neck muscles on one side.
Affects the entire face not just the mandible.
facial Asymmetry
Masseter muscle was largely missing on left side
Decrease in tonic muscle activity results in
too much vertical growth, excessive eruption of posterior teeth. and severe anterior open bite
Mesiodens
supernumerary teeth
most common mesiodens
appear in Maxillary Midline
The neural tube forms
during days 18-23 in utero
achondroplasia
deficient growth of cartilage found in humans& dogs
dominant gene..so sometimes only partially expressed
anchondroplasia is due to
deficient growth the synchondroses of maxilla
achondroplasia results
results in humans short limbs cranial base does lengthen
modern reason for crowding
Increased outrbreeding
Crowding caused by mix between heredity and environment
normal tongue thrust is associated with
with normal teeth together swallow
History of thumb sucking and
tongue. thrusting forward to open bite.
tongue crib
habit appliance
fixed to lingual arch and soldered to upper 1st molar bands
prevents digit sucking habit
myofunctional bead
tongue training appliance
hait appliance
bluegrass
digit sucking appliance
teflon roller trains tongue
in severe maxillary
Maxillary teeth fit inside the mandibular
but no mandibular shift
treatment of crossbite
early correction(primary if must) for Posterior crosstie&mild anterior cross bite. surgery for severe anterior crossite
most common transverse discrepancy intramurally
Posterior crossite
the rule of thumb .. 3 or more than 3 teeth in crossbite
Definition of crossbite
Abnormal buccolingual or labiolingual relationship of teeth
diagnosis of posterior cross bite
Dental: Functional shift,Lingual inclination of maxillary dentition,,, Adequate width of maxilla and mandibular apical base
Skeletal:No functional shift, Narrow palatal vault, buccal inclination of max dentition
what is orthodontic triage for chlldren
- syndrom/developmental abnormalities
- Facial profila analysis
- Dental development
- Space problems”
- Other occlusal discrepancies
true or false
tooth eruption is well correlated with skeletal growth
False
tooth eruption is not well correlated with skeletal growth
Nance holding arch
space maintainer of upper arch
prevents medial molar drift
can be used as anchorage
drawback of Nance holding arch
tissue irritation
Indication for Partial Denture
Most useful when more than one tooth has been lost per segment & permanent incisors have not erupted yet.
Posterior space maintenance and replacement of anterior teeth for aesthetics
advantages of partial denture
replaces occlusion function
Pendulum is indicated for
regain 4-5 mm of space
used to correct class ii molars 1a class 1 skeletal case
used to distalize max 1st molars
distal shoe
space maintainer -permanent molars and canines
indicated when 6s have not erupted and E’s has been lost prematurely
Metal or plastic guide plane is attached to a band or from
Headgear
Extraoral appliance with two components
Serial extractions Advantages
Reduces anterior irregular
Dental cross bite
has a normal maxillary width the changes are do to movement of canine
the W arch
Correction of dental crossbones
moves primary and permanent teeth.
maxillary fixed movable appliance(expand b4 insertion)
used when 4-5mm of expansion Maxillary -bucul
cross bite with functional shift is a sign of what orgin
dental
also should have adequate width of maxilla and mandibular base
two considerations in determining optimal treatment time
Effectiveness: how well does it work
efficiency : what is the cost benefit ratio
When is early treatment indicated in class 1 problem
in posterior crossbite WITH mandibular shift
crowding : early correction ism more controversial
early treatment indicated in class 2 problems
Mandibular prognatismo : effects to restrain at early stages
Maxillary deficiency : facemark treatment is successful if done early
horseshoe shaped acrylic plate fitting along the lingual surfaces of teeth
Schwartz plate
expands max or mand arch
Hyrax expanders
Corrects SKELETAL cross bite
stainless steal bands attached to maxillary 1st premolars and 1st molars ..band connected to expanding screw via ridge wires
one quarter. turn of a screw=
.25mm
what I considered slow expansion
1mm/WK or 10mm/10weeks(rapid an slow same over 10 wk period)
rapid expansion is considered
0.5mm/DAY. 10mm/10WKs( same as slow over 10wks)
creates 10-20 lbs of weight across suture
hyax expanders
attach to 1st maxillary molars and premolars
correct SKELETAL posterior crossbite
bonded hyax expanders
bonded to enamel
Skeletal posterior crossbite correct
controls bite opening
extreme cases
when is treatment of posterior crossbite not indicated
if first molars with erupt in 6 months or less
1mm of posterior expansion =_ arch length
.7 increase in arch length
drawbacks of Maxillary expansion
Extrusion causing Cuspal Interference &
Mandibular rotation
extrusion of the palatal cusp with decrease open bite
extrusion of palatal cusp will increase open bite
max expansion is not indicated for what face type
dolicofacial
Salzmann classifaction
Group 1- prenatal
group 2- post natal
Headgear
space regaining
good option for bilateral tipping or oddly movements
lip bumper
U shaped stainless steel wire
Anterior portion may carry a plastic or acrylic pad 2-3mm away from the alveolar process of lower incisors
Lingual arch indications
Bilateral space due to lingual incisor tipping
limited space regaining
moderate arch expansion
how do you assess results of early treatment
Removal and or control of etiologic factors
Satifactory tooth positions and space management
satisfactory corruption of skeletal problem
when is it recommended to be seen by orthodontist
age 7
trans-palatal arch(TPA)
Maxillary fixed/fixed-removale appliance
Space maintainer
Extends from one maxillary 1st molar to the opposite max 1st molar
Band and loop is indicated when
indicated for unilateral loss of primary molar when premolar will not erupt for more than 6 months
mandibular space regain consist of
adjustable lingual arch and lip bomber
Removable appliance and finger springs
removable appliance in Molar distiizatoon
Helps regain 2-3 mm in maxillary space
great with unilateral problem
USUALLY regains 2-3mm baby tipping the max 1st molar distally
space supervision
utilization of leeway space to unravel lower anterior crowding
do not begin until lower canines and 1st premolars show 1/4-1/3 of root formed
extreme maxillary constriction
max inside mandible
no functional shift
cleft lip and palate cause by
failure of fusion of medial and lateral process
Pendex
molar distilization appliance
