The hand-wrist structures used to determine the ossification events were:1. initial ossification of the pisiform. This occurs before peak growth velocity in almost all children. 2. initial ossification of the ulna metacaro-phalangeal sesamoid of the thumb (“sesamoid”). This becomes visible at peak growth. 3. attainment of epiphysis caping of its diaphysis in the proximal phalanx of the first finger (“growth plate” in my simple thinking). Caping happens near the peak growth, but is on the deceleration side of the curve. 4. complete epiphyseal union in the distal phalanx of the third finger. This follows the peak growth period in almost all children.

Ossification of the sesamoid and pisiform were related to the height velocity curves, showing an average of 1.3 years from pisiform ossification and 0.3 years (boys) and 0.5 years (girls) from sesamoid ossification before “peak” height velocity. Epiphysis caping and union (event 3+4 above) happened in the “decelerating” part of the growth curve.

Timing from the cervical vertebrae (C2,C3,C4) were defined by the concavity of the lower border as well as the shape of C3/C4 as 1) trapezoidal, 2) rectangular-horizontal, or 3) square or rectangular-vertical, using the work of Baccetti. There is a progressive deepening of the inferior concavities of C2/C3/C4 as the patient passes through the pubertal growth spurt. “CVM stages” were defined as:

CVM Stage 1: trapezoidal (early age). The vertebrae are “flat” on the inferior border with a possible slight concavity on the lower border of C2. The shape of C3 and C4 are a trapezoid.

CVM Stage 2: C2 now has a concavity on the inferior border with a slight concavity on C3. The shape of C3+C4 are now a trapezoid or rectangular-horizontal. The vertical height of the vertebrae is increasing.

CVM Stage 3: The concavities are now visible on all the vertebrae with the C2 concavity deepening. The vertebrae are now rectangular-horizontal (horizontal refers to the longest side of the rectangle being in the horizontal direction)

CVM Stage 4: The concavities of the 3 vertebrae are deepening with the shape becoming square. It is possible that C4 will still be rectangular-horizontal (height did not increase as much to make the square out the rectangle).

CVM Stage 5: The height of the vertebrae increases, making the shape of C3 rectangular-vertical (longest side of rectangle is now vertical). C4 can now remain square or also become rectangular-vertical. The concavity of C4 has deepened further.

CVM stages 1+2 preceded the peak growth period. Stages 3-4-5 in girls followed the peak growth velocity. In Boys, stage 4+5 definitely followed the peak, with stage 3 being variable.

The events of both the wrist x-ray and cervical vertebrae were plotted on the height velocity curve for boys and girls, relating these to the overall pubertal growth spurt. Combinations of the wrist and CVM events can be seen as they relate to the peak.

Class II treatment can be started early, but there is a feeling that a “one-stage” treatment approach during adolescence is more efficient (vs. phase I+II treatment phases). Assessment of a patient’s cooperation level combined with growth prediction is important in treatment planning. These authors recommend the following protocol for the start of Class II treatment timed to the pubertal growth spurt.

CVM stage 1: wait for at least 1 year before asking for another lateral ceph. Combination Pisiform (wrist) + CVM stage 2: delay the orthopedic treatment phase. Combination Sesamoid + CVM stage 2 in girls: start treatmentCombination Sesamoid + CVM stage 3 in boys: start treatment

Adding the wrist x-ray to the evaluation adds radiation exposure, but is less likely to be mis-interpreted than the CVM stages in the clinic. The depressions of the vertebrae are subtle changes. Care must be used to not obscure the vertebrae with the protective thyroid collar. The best assessment of growth is found when combining both methods, but this involves the most radiation exposure. The wrist x-ray is the best if you only have one choice as the events are more clear. The hand-wrist x-ray can also be used to estimate mature heights.