Growth patterns and timing and their measurement and growth prediction Flashcards
5 methods of growth timing and rate of growth
- Measurement of change in height
- Secondary sexual characteristics
- Hand-wrist radiographs
- Radiographic assessment of cervical spine maturation
- Average growth increments
PHV
Peak height velocity, maximum rate of growth
Happens during puberty
Ideal time for orthodontics
Pubertal growth spurt gives acceleration of facial growth rate
Raises possibility of wroth modification
Permanent dentition establishes itself
General Scammons growth curve
Typical of most systems of body including skeleton and muscle mass
Neural growth curve
Shows graph of brain, NS and associated structures (incl. cranial vault, orbits and part of upper face)
Genital growth curve
Genital tissues experience particularly rapid growth during adolescence
Lymphoid growth curve
Lymphoid tissues grow rapidly in childhood, by 12 represent ~2x size of relative final size
Tonsils in particular reduce in size during adolescence
Standing height
Facial growth occurs ~ same time as growth in height
-exception of orbits and part of upper face
Can be used as proxy for growth in facial structures
Stnadiometer, stood in front of with bare feet
Plotting an Individuals Growth
De Montebeillard’s graph
Volocity, showing height gain in cm per year
Sharp peak at puberty visible: PHV
Growth charts
Tanner growth chart
Also possible to assess growth rate by obtaining sequential weight recordings as well as height (less accurate)
Children in contemporary UK are considerably taller
Orthognathic treatment
Px ought to have completed growth before commencement of treatment
Limitation of using height measurement to time
> gradient to plotted line can be subtle/ difficult to detect
PHV only detected after it has happened
Velocity chart layout
Age along horizontal and height gain per year along vertical axis
Changes in velocity
Post-natal growth characterised by rapid, then rapidly declining growth in early years
Levels off from 4-10
Increases again during pubertal growth spurt
Tails off to 0 by 16 for girls and 18 for boys
PHV often reached at same time as PHV for craniofacial tissues
Intermittent growth
Not continuous process
Assessing sexual maturity
Quite obvious when it is happening
Hand wrist radiographs
Large umber of ossification centres present in relatively small area
The Atlas Technique
Ulnar sesamoid bone ossifies at start of pubertal growth spurt
No more accurate than height measurements and it uses radiation
Further use of radiographs
Cephlaogram : cervical spine maturation
Already taken for other reasons
Bacetti method: examining 3 cervical vertebrae
Peak mandibular growth velocity would occur in within one year of CVMS II
Computer programme use in making growth prediction
Ricketts devised visualised treatment objective (VTO)
- uses average growth increments for each age to give expected growth
- much of data produced does not reflect final outcome as there are great variations
Craniofacial changes in adults
> in all facial dimensions continues throughout life
Vertical changes most prominent, antero-posterior changes less prominent
Little change in width
Female growth resumes in 20s
Magnitude is small but cumulative
Growth rotation continues, average small < in face height, compensatory changes occurs in dentition
Soft tissue changes in adults
> changes occur in soft tissues than hard tissues
Lip incompetentcy < with age
Lower lip grows more, and combined lip growth exceeds lower face height
