Ortho Flashcards
Syndrome vs Sequence
Syndrome:
* pattern of annomolies
* that occur together in a predictable fashion
* due to single etiology (genetic)
* Like a recipe from a cookbook
Sequence:
* Group of related anomalies
* Stem from a major anamoly
* alters the development of surrounding structures
* like a row of dominos
Fetal Alcohol Syndrome: Cause
Exposed to high levels of ethanol
* Teratogen=alcohol
Fetal Alcohol Syndrome: S/S
CNS problems: Neural Plate Tissue Deficiency
* abnormal brain development
* microcephaly (small head)
Midface deficiency:
* smooth philtrum
* thin upper lip
* small parpebral fissures
Treacher Collins Syndrome: Cause
Genetic Mutation:
Altered development of neural crest cells
Treacher Collins Syndrome: S/S
underdevelopmed mandible
Downslanted palpebral fissures
Celft palate (35%)
Microtia (Small ear)
Hemifacial Microsomia: Cause
Loss of neural crest cells during migration
Hemifacial Microsomia: S/S
Deficient Ear & Mandibular Ramus
* On affected side
Down syndrome: Cause
Nondisjuction leading to extra chromosome 21
Down syndrome: S/S
Midface deficiency
Upslanted palpebral fissures
No Increased caries risk
Increased perio risk
Cleft Lip & Palate
Class 3 w/deficient maxilla
Cleft Lip:
* week 4-6 in utero
* No fusion b/w Medial Nasal Prominence and Maxillay Process Anteriorly
* Usually off midline and unilateral
Cleft Palate:
* week 6-8 in utero
* No fusion b/w Medial Nasal Prominence and Maxillary Process posteriorly
* Primary Palate: caries lateral incisor to lateral incisor. why they are missing lateral incisors
* Complete Cleft Palate: Primary and Secondary palate both do not fuse
Pierre Robin Sequence
Mary Gray Cunningham BF is Difficult
- Micrognathia (small mandible)
- Glossoptosis:
- Cleft Palate
- Breathing & Feeding Difficulties
Crouzon Syndrome: S/S
Craniosynostosis: early closure of skull sutures
(Brady’s Hyper Front Boss has Prop Class @ 3)
Brachycephalic (short skull)
Midface deficiency
Frontal Bossing (Prominent forehead)
Hypertelorism (wide separated eyes)
Proptosis (Bulging eyes)
Class 3 occlusion
Alpert Syndrome: S/S
Craniosynostosis:
Acrocephalic: Tall Skull
Byzantine Arch: (narrow palate w/high vault)
Syndactyly (Fused fingers and toes)
Hurler & Hunters Syndrome
Build up of Glycosaminoglycans (GAGs)
* Due to enzyme deficiency
HURL.. vomitting.. GAG
Gum Pad Stage
Birth to 6 months
End=eruption of 1st primary tooth
- lateral Sulcus: separates primary K9 from primary 1st molar
Primary Dentition Stage
6 months to 6 y.o.
Minimal OB & OJ
Interdental Spacing
Space b/w primary incisors
normal Space
* permanent incisors filll gaps
* w/o=crowding
Primate Spacing
Max: B/w primary lateral & K9
Mand: B/w Primary K9 & 1st molar
Leeway Spacing
Difference of combined MD width b/w:
* primary K9/1st molar/2nd molar
* permanent K9/1st premolar/2nd premolar
Gains us space:
* permanent premolars are smaller than primary molars they replace
Max: 1.5 mm per side (3mm total)
Mand: 2.5 mm per side (5 mm total)
Primary Molar Relationships
Relationship b/w:
* Mandibular Terminal Plane
* Maxillary Terminal Plane
Mixed Dentition Stage
6 yrs to 12 yrs
end=exfoliation of last primary tooth
* interdental, primate, and leeway spaces all close
Ugly Duckling Stage
11-12 yrs old
Hallmark: diastema b/w 8 &9, </= 2mm
* closed w/max K9 eruption
If > 2mm: will not close fully
Anterior Transition:
permanent tooth buds are lingual and apical to primary counterparts
Incisors erupt lingually
* Except Upper Central & K9s erupt labially
Posterior Transition
Flush terminal plane–> class 1 by differential teeth shift and differential jaw growth
Early Mesial Shift= 1st molars -> close primate space (around 6 y.o.)
Late Mesial Shift=2nd molars ->close leeway space (around 12 y.o.)
Late mandibular growth
Mixed Dentition space analysis
compares Space available and space required for incoming permanent teeth
requires all 4 lower incisors erupted
Objective: Predict MD width of unerupted B segment (k9/1st and 2nd premolar)
Ideal OB and OJ
OB: 10-20%
OJ: 1-3 mm
Late Lower Incisor Crowding
Anterior crowding gets worse in 20’s and 40s
* Due to late mandibular growth
Results in:
* Added pressure on lower incisors
inter canine Width
Increase as permanent teeth erupt
Intermolar width
Increases as molars erupt then stabilizes
More expansion in max vs mandibular bc:
* Upper erupt divergently and lower erupt convergently
Arch Length
Decrease during transition from mixed to permanent
Arch Perimiter
Increase in Max
Decrease in Mand
During transition from mixed to permanent
Ackerman-Profit Diagnostics
Facial Proportions and Esthetics:
* Lip Posture
* smile arc
Alignment & Symmetry:
* crowding
* Spacing
* rotation
Transverse:
* Posterior cross bite
* Midline
Anteroposterior:
* OJ
* Angles Class
Vertical:
* OB
* CUrve of spee
Malocclusion
Bad Bite
Genetic Disposition
Molar Classification
Overjet
Horizontal Overlap: labial surface to labial surface
Normal: 2-3 mm
Excess > 3mm
Reverse OJ: Max incisors behind mandibular incisors
Overbite
Vertical Overlap: Incisal edge to incisor edge
Normal: 1-2mm
Anterior Crossbite
Aka Reverse Overjet
Maxillary Anteriors are behind Mandibular anteriors
Posterior Crossbite
Aka Scissor Bite
Maxillary posterior teeth are lingual to mandibular
* Or completely buccal
Bolton Analysis
Measures Tooth Size Discrepancy
* compares Upper and lower teeth
Too large=Interproximal reduction (IPR)
Too Small=Buildup
Face: Vertical 1/3s
Face: Horizontal Fifths
Skeletal Classification: Class 1 vs 2 vs 3
Class 1:
* jaws well related to N-vertical
Class 2:
* Prognathic/protrusive maxilla
* Retrognathic/retrusive mandible (most common)
* Combo of both
Class 3:
* Prognathic mandible
* Retrognathic Maxilla (most common)
* Combo
Facial Profile
Facial plane formed by: GLabella, Subnasale, ST pogonion
Straight: Class 1
Convex/Posterior Divergence: Class 2
Concave/Anterior DIvergent: class 3
Nasolabial Angle
b/w nose and upper lip
90 degrees
Mentolabial Fold
Aka Mentolabial Angle
b/w lower lip and chin
120 degrees
Cervicomental Angle
b/w chin and neck
90-120 degrees
Lips
3 P’s:
Position:
* Rickets E Plane (line from nose to chin)
* Lower lips should be behind
* Upper lips should be on the line
Posture=lip competence at rest
* competent vs incompetent
* Incompetent=3-4 mm seperation at rest + Mentalis strain on closure
Proportions:
* How much vermilion is showing?
* Thick or thin lips
Incisal Display
at Rest:
* Ideal: 2-4 mm show
On Smile:
* Ideal: 75-100% incisor w/1-2 mm gingival show
S-N Reference Plane
Cranial base
Po-Or Reference Plane
Frankfort Horizontal
ANS-PNS Reference Plane
Palatal Plane L6-L1: Occlusal Plane
Go-Gn reference plane
Mandibular plane
Sassouni Analysis
All reference planes should intersect at back of head (Occupit)
Intersect earlier: Hyperdivergent
Intersect later: Hypodivergent
SNA
maxilla to cranial base
* large angle-Prognathic Max
* Small Angle: Retrusive max
SNB
Mandible to cranial base
* Large angle: Protrusive mandible
* Small angle: Retrusive mandible
ANB
Maxilla to Mandible
</= 0 degrees: Class 3
2 Degrees: Normal Class 1
>/= 4 degrees: Class 2
Soft Tissue Paradigm
Cephalometric analysis
eval relationship b/w jaws & teeth
use:
* SNA
* SNB
*ANB
Phase 1 ortho treatment
Early treatment during Mixed dentition
Phase 1 Ortho tx: Posterior Crossbite
Transverse issue: narrow palate
Tx early if functional shift
* can cause skeletal asymmetry as pt grows into malocclusion
Tx: Palatal Expansion
Phase 1 Ortho tx: Anterior Crossbite
Few teeth:
* dental issue
* results in wear & gingival strain
* Tx: 2x4 braces or active retainer
Full Underbite:
* Skeletal class 3 malocclusion
* Tx: Reverse Pull headgear
Phase 1 Ortho tx: Severe Overjet
Increased risk of Trauma
Psychosocial concern
Phase 1 Ortho tx: Anterior Open Bite
Causes:
Thumb sucking:
* narrow maxilla w/posterior cross bite
* Proclaimed max incisors & retroclined mandibular incisors
Tongue Thrust:
* Proclaimed incisors w/generalized spacing
Phase 1 Ortho tx: Impacted Teeth
Kurol’s Rule:
* K9 Not past midline of lateral incisor=91% chance of eruption
* K9 past midline of lateral incisor=64% chance of eruption
3 H’s:
* How High?
* Is it horizontal?
* Has it crossed midline of lateral?
Phase 1 ortho tx: Moderate Crowding
> /= 4 mm crowding
* not a big deal in mixed dentition bc of leeway space
* No EXTractions
Tx: Focus on maintaining space for permanent teeth
* Lip bumper
* LLHA
Phase 1 ortho tx: Severe Crowding
> /= 8mm crowding
Tx: Serial Extraction (C-D-4)
* start when max perm laterals erupt: EXT C’s (Primary K9s)
* Ext primary 1st molars
* Perm 1st premolars Erupt= Ext Them
Contraindication:
* Skeletal Discrepancy
Class 2 appliances: General
Headgear:
*restrains max growth
Functional appliances
* Stimulate mandibular growth
Class 3 Appliances: General
Reverse headgear:
* stimulates max growth
Chin cup
* Restrains mandibular growth
Headgear
Best Prepubertal
Growth Modification
High-Pull Headgear
Aka Occipital-Pull Headgear
* Class 2
Skeletal: Restrains max forward growth
Dental: intrudes and distalizes upper molars
Best for Class 2 Open Bite:
* Class 2: restrains max growth
* Open Bite: Intrudes posterior teeth
Low-Pull Headgear
Aka Cervical-Pull Headgear
* Class 2
Reverse-Pull Headgear
Facemask
* Class 3
Chin Cup
Class 3
Growth Modification: Age of Boys vs Girls
Girls: 8-13
Boys: 10-15
