Fishman proposed Skeletal Maturation Indicators (SMI) in radiographs of the hand and wrist to evaluate the skeletal maturation of older children and adolescents. This is useful to dentists in assessing patients for orthodontic procedures.
Procedure:
(1) A radiograph is taken of the hand and wrist.
(2) Certain features correlated with skeletal maturity are looked for in different bones.
|
Feature |
Specific Finding |
SMI |
|---|---|---|
|
width of epiphysis is as wide as diaphysis |
proximal phalanx of third finger |
1 |
|
|
middle phalanx of third finger |
2 |
|
|
middle phalanx of fifth finger |
3 |
|
ossification |
adductor sesamoid of thumb |
4 |
|
capping of epiphysis |
distal phalanx of third finger |
5 |
|
|
middle phalanx of third finger |
6 |
|
|
middle phalanx of fifth finger |
7 |
|
fusion of epiphysis and diaphysis |
distal phalanx of third finger |
8 |
|
|
proximal phalanx of third finger |
9 |
|
|
middle phalanx of third finger |
10 |
|
|
radius |
11 |
where:
• In SMI 1-3, the epiphysis and diaphysis are parallel, while for 5-7 the epiphysis is concave.
Scheme for evaluating radiographs:
(1) Is there ossification of the adductor sesamoid for the thumb (SMI 4)?
(1a) No: consider SMI 1 - 3.
(1b) Yes: go to #2.
(2) Is there fusion of the distal phalanx of the third finger?
(2a) No: consider SMI 5 - 7.
(2b) Yes: consider SMI 8 - 11.
Expected Age to Reach Indicator
|
|
females (age in years) |
||
|---|---|---|---|
|
indicator |
early |
average |
late |
|
1 |
9.157 |
10.23 |
11.302 |
|
2 |
9.8 |
10.722 |
11.643 |
|
3 |
9.914 |
10.872 |
11.831 |
|
4 |
10.072 |
11.041 |
12.011 |
|
5 |
10.549 |
11.708 |
12.867 |
|
6 |
10.802 |
11.955 |
13.108 |
|
7 |
11.369 |
12.512 |
13.655 |
|
8 |
12.26 |
13.263 |
14.265 |
|
9 |
12.636 |
13.967 |
15.298 |
|
10 |
13.626 |
14.89 |
16.154 |
|
11 |
14.791 |
16.508 |
18.225 |
(Table 2, page 183, Fishman)
|
|
males (age in years) |
||
|---|---|---|---|
|
indicator |
early |
average |
late |
|
1 |
10.248 |
11.368 |
12.488 |
|
2 |
10.955 |
11.921 |
12.887 |
|
3 |
11.109 |
12.211 |
13.312 |
|
4 |
11.351 |
12.574 |
13.797 |
|
5 |
11.835 |
13.029 |
14.224 |
|
6 |
12.571 |
13.779 |
14.987 |
|
7 |
13.23 |
14.429 |
15.629 |
|
8 |
14.185 |
15.194 |
16.203 |
|
9 |
14.289 |
15.485 |
16.682 |
|
10 |
14.958 |
16.174 |
17.39 |
|
11 |
15.815 |
17.242 |
18.669 |
(Table 3, page 183, Fishman)
Specialty: Surgery, orthopedic, Pedatrics
