Exam 1 Flashcards
When does the initiation of the entire dentition begin?
During the 2nd month in uterine
Does the lamina grow facially or lingually to the enamel organ of deciduous teeth?
Lingually
(Hint it grows in the simplest direction the one with one name baby teeth (deciduous) can’t remember 2 names
When does the 1st permanent molar develop?
4 months in utero
2nd permanent molars develop when?
1yr old
3rd permanent molars (wisdom teeth) develop when?
4-5yrs old
What is the Field Theory(Butler) relating to the pattern of dentition?
There are 3 morphological fields: -incisor -canines -premolars/molar
Sequence of eruption of primary dentition. (Think chart)
Central: mand 8months max 10 months Lateral: max 11 months mand 13 1st molar: 16 months BOTH max&Man Canine: max 19 man 20 Second molar: mand 27 Max 29
In order to effectively use functional jaw orthopedics what is imperative for correction.
The presence of growth
What are the effects of the treatments with Twin Block Appliance
Brings mandible toward and maxilla backwards for class 2 correction
Etiology(cause) of malocclusion?
Genetic
EmbryologicAl
Antenatal
Congenital and postnatal
The definition of Classification:
The morphologic description of dental, skeletal,
and soft tissue deviations from the norm.
Edward Ange
Developed orthodontics as a specialty
Developed ‘edgewise appliance”
According to Angle ‘the key to occlusion” is
Maxillary 1st molars
Describe the Line of occlusion
a smooth curve
passing through the central fossa of
each molar and across the cingulum
of the upper canine and incisors
same line runs along the buccal
cusps and incisal edges of the lower
teeth
Class 1 malocclusion
Has the same relationship as normal occlusion
but Line of Occlusion -(twisting, maloppoosed)
Class II Malocclusion
lower molar position distally to upper
Weakness in Angles Theories
Angle assumed that 1st molar was always in the correct location
Gave no skeletal consideration
His classifications only considered the Anterior-posterior displacement
What are the percentage of natural occurrence of Angle’s 4 groups?
According to NHANES survey the most prominent is Class 1 malocclusion 50% Normal occlusion 30% Class II = 15% ClassIII= less than 1%
Brachyfacial type
A broad square face with a strong chin,
flat MP(mandibular plane), a straight
face
What would happen if anterior crossbite was untreated?
Warping of the alveolar ridges
Periodontal problem
Why is treating anterior crossbite important?
Because primary teeth positions influence the developing permanent tooth buds.
Eruption of first molars
Happen 14months mandibular
13 month maxillary
Transition from infantile swallowing to more mature pattern
Eruption of canines
17 months mandibular
16 months maxillary
Max cusp tips distal to canine
Eruption of second molars
23 months mandible
25 months maxilla
Definite occlusal plane
Causes stabilization of dentition
Gum pads in the neonatal stage
Become alveolar processes at time of birth
Upper arch•houseshoe shaped
Lower arch • U shaped
Pink in color, firm an covered by a dense periosteum
Pacifier use beyond age 24 months is associated with
Significant greater prevalence of posterior crossbite
Pacifier extended 48 months or longer
Cause the greatest change in dental arch an occlusal characteristics
The tip of the tongue is responsible for what sounds
T d
S, z
When do we translate to adult chewing pattern?
About age 12
Related to eruption of permanent canine
In order for newborns to open airway
The mandible must be positioned forward and downward, away from the posterior pharyngeal wall
Allows air to move through nose pharynx and lungs
Adult swallow
- relaxed lips
- tongue against the alveolar process behind maxillary incisors
- posterior teeth brought into occlusion during swallowing
- 60% achieve at age 8
If sucking persist no adult swallowing
Suckling vs sucking
Suckling to obtain milk
Is small nibbling movement of lips
Stimulate smooth muscles in lactic gland to contract an secrete
•SUCKING
Draw
successional teeth
Replace deciduous predecessors
incisors,canine & premolar
formation between 20 weeks in utero and 10 months of age
Accessional teeth
No deciduous predecessors
molar
Formation begins between 14 weeks in utero and 5 yrs of age
Nolla stages
Serial radiographs to evaluate dental development
10 stages of tooth development
what are the most important Nolla stages
Stage 2- Calcification
Stage 6- crown completion
Nolla stage 6
Movement begins when crown formation complete
Nolla’s stages 7~8
emergence at vary degree of root development
canine 2/3 of root formed
premolar: 1/2 of root formed
Molar: 1/3 of root formed
Nolla’s stage 9
Occlusion achieved
Root almost completed but apex still open
What are the developmental processes during eruption of successional teeth
Resorption of primary tooth elongation of the permanent tooth root Increase in alveolar height Movement of permanent tooth occlusally Less growth in the inferior border of the mandible
What are the stages of tooth eruption
Pre-emergent eruption: eruption movement in the bone
Post emegent eruption: passing through alveolar crest
Pre-emergent eruption
begins with root formation
1st step: resorption of bone and primary tooth roots
2nd step: Eruption mechanism itself in the direction where the path has been cleared
Post - emergent eruption
Post-emergent spurt
Juvenile occlusal equilibrium
Adult occlusal equilibrium
Post-emergent spurt
Rapid eruption after eruption into mouth
Juvenile occlusal equilibrium
Slowing of eruption after contacting with opposing dentition
Rate of eruption equal to the rate of vertical growth of mandibular ramus
Spurts in eruption accompanies spurts in jaw growth
Adult occlusal equilibrium
Continue to erupts at an extremely slow rate
Compensate for loss of tooth structure
