FACIAL GROWTH (8) Flashcards
Define General Growth
An increase in size by natural development and is a consequence of cellular proliferation and differentiation.
What are the 4 main tissue growth patterns?
1) Lymphoid
2) Neural
3) Somatic (general)
4) Genital
Which of the 4 tissue growth patterns is most relevant to general height?
Somatic (general)
Which 2 of the 4 tissue growth patterns are most relevant to craniofacial growth (maxilla/mandible)?
Neural
Somatic (general)
What is the purpose of a growth chart?
Assessment of general growth height/age.
So for a general population you can look at where your child is in relation to their growth vs population of similar age
Describe the 3 phases of Rate of Growth
- Rapid growth at birth, progressively decelerates until 3 years.
- Slowly decelerating phase, persisting until adolescent growth spurt in early teenage years (brief juvenile growth spurt at 6-8 years)
- Adolescent growth spurt, followed by progressive deceleration until adulthood.
What is a Growth velocity chart?
rate of change in height / age
What does the peak represent on a Growth velocity chart?
peak = growth spurt
What is the age range for growth spurt in girls?
10.5-12.5 yrs (2yr duration)
What is the age range for growth spurt in boys?
12.5-14.5 yrs (2yr duration)
Complete this sentence:
Growth spurt begins ……. before Peak Height
Velocity (PHV
1 year
What does the trough represent on growth velocity chart?
Trough = growth cessation
What age do boys stop growing?
17-19 yrs
What age do girls stop growing?
15-16yrs
Complete the sentence:
Males have …….. and ……….. adolescent growth spurt
later and greater
Why is general growth prediction useful for ortho?
If we know where the pt is on the chart, then we can anticipate further growth.
Name 2 methods of predicting future growth.
- Sequential height measurements
- Secondary sexual characteristics
What are the stages of adolescence in girls?
I) Early breast development
II) Axillary (armpit) pubic hair development
III) Onset of menstruation
What are the stages of adolescence in boys?
I) Fat spurt
II) Initial pubic hair development
III) Armpit and upper lip facial hair development
IV) Chin facial hair development
If a boy has upper lip facial hair development, then what does this mean based on the growth chart?
They are at or beyond peak rate of growth
If a boy has chin facial hair development, then what does this mean based on growth chart?
They are beyond peak rate of growth
True or False:
Patients general growth may help us anticipate facial growth
True
The maxilla has growth pattern between neural and somatic but is closer to …..
neural
The mandible has growth pattern between neural and somatic but is closer to …….
somatic
Name 2 basic mechanisms of growth
Relocation (growth remodeling)
Growth displacement
Name the 3 planes the facial skeleton is assessed by:
Antero-Posterior (AP)
Vertical
Transverse
Describe the Growth of Maxilla— Antero-Posteriorly
- Part by displacement forwards with bony in-fill at
sutures - Part by periosteal remodeling
- Tuberosities grow backwards, lengthening dental arch
Describe the Growth of Maxilla – Vertically
- Increase in height of alveolar process
- Downwards drift of hard palate with remodeling
- Bony in-fill at sutures
Describe the Growth of Maxilla— Transverse
- Two halves of maxilla move apart (bony in-fill at
midline suture) - Nasal cavity and air sinuses increase in size
Describe the Growth of Mandible— Antero-Posterior
- Mandible displaces anteriorly
- Meanwhile growth fills-in at condylar cartilage causing
lengthening - The mandible remodels, esp. anterior region
- Chin becomes more prominent (esp. in males)
- Normal increase in length is 2-3mm per year, doubles
during pubertal growth spurt
Describe the Growth of Mandible — Vertical
- Alveolar process becomes taller as teeth erupt
- Ramus becomes taller
- Growth fills in at condylar cartilage causing lengthening of mandible and increase height of mandible.
Describe the Growth of Mandible— Transverse
- Remodelling with resorption on inner surface and
deposition on outer surface - Increases width esp. posteriorly
Why does Remodelling with resorption on inner surface and
deposition on outer surface occur?
To maintain shape of mandible
AP Normal Development class I is what?
Mandible 2-4mm posterior to maxilla
AP Normal Development class II is what?
Mandible more than 4mm posterior to maxilla
AP Normal Development class III is what?
Mandible is less than 2mm posterior to maxilla
AP growth stops at what age for boys?
19yrs
AP growth stops at what age for girls?
16-17yrs
For a Class II pre-pubertal is there a potential for improvement or worsening in pubertal growth spurt?
Slight improvement especially if functional appliance is used
For Class III pre-pubertal is there a potential for improvement or worsening during pubertal growth spurt?
Potential to worsen
If you see a Class III skeletal pattern in young child, it is best to refer for ortho assessment before what age?
10
What are the treatment options for Class III?
Orthodontic camouflage (braces only +/- extractions)
Surgical correction in more severe cases
How is Vertical Development proportions assessed?
Using facial thirds and FMPA (Frankfort Mandibular Plane Angle)
What age does Vertical growth stop for boys?
Early 20s
What age does Vertical growth stop for girls?
17-18yrs
Name 4 signs of Increased vertical proportions (abnormal vertical development)
- Increased FMPA
- Increased Lower Anterior Facial Height
- Reduced overbite or Anterior open bite
- Downwards/backwards/ clockwise growth rotation
Name 4 signs of Reduced vertical proportions (abnormal vertical development)
- Reduced FMPA
- Reduced Lower Anterior Facial Height
- Increased overbite
- Forwards/ anticlockwise growth rotation
Is this feature of Normal Transverse Development or Abnormal Transverse Development?
No asymmetry extra-orally (around mid-facial plane)
Normal transverse development
Is this feature of Normal Transverse Development or Abnormal Transverse Development?
Maxillary and mandibular centre-lines coincident to each other and the mid-facial plane
Normal transverse development
Is this feature of Normal Transverse Development or Abnormal Transverse Development?
No crossbites (although these can occur for other reasons)
Normal transverse development
Is this feature of Normal Transverse Development or Abnormal Transverse Development?
Facial asymmetry
Abnormal transverse development
Is this feature of Normal Transverse Development or Abnormal Transverse Development?
Unilateral or bilateral cross bite
Abnormal transverse development
Is this feature of Normal Transverse Development or Abnormal Transverse Development?
Centreline discrepancy
Abnormal transverse development
What age does transverse growth stop for boys?
Approx 12 yrs
What age does transverse growth stop for girls?
Approx 12 yrs
3 types of Facial asymmetry?
Mandible
Maxilla (cant)
Pan-facial
A bilateral buccal crossbite may be due to……
Transverse skeletal discrepancy between the maxilla and mandible
When is a Rapid Maxillary Expansion best done?
Before fusion of mid-palatal suture
What 4 things would we like to predict for growth?
- Future size
- Rate of growth and when it will occur
- Direction of growth (rotations)
- Soft tissues
Name 4 methods of assessment of Growth prediction
- Chronological age
-Growth charts - Secondary sexual characteristics
-Radiographs (lateral cephalograms)
Why are hand-wrist radiographs no longer used?
Unreliable
Inaccurate
Why is CS3 important for orthodontists?
CS3 is optimum time for functional appliance treatment and is start of growth spurt
Growth spurt has finished by which CS number?
CS4
What is the most common growth rotation?
Anti-clockwise (upwards/forwards)
What is the less common growth rotation?
Clockwise (downward/ backward)
Name the 7 structures from lateral cephalogram that helps to identify rotation direction of growth?
- Inclination of condylar head
- Curvature of mandibular canal
- Shape lower border of mandible (antegonial notch)
- Inclination of mental symphysis
- Interincisal angle
- Intermolar and interpremolar angle
- LAFH
