Abstract

References
1.
Atkinson
M E
. (1972 ) Journal of Oral Pathology
1 , 115 .
2.
Harris
M
Toller
P
. (1975 ) British Medical Bulletin
31 , 159 .
3.
Lewin-Epstein
J
. (1964 ) British Journal of Oral Surgery
2 , 115 .
4.
McHugh
W D
. (1961 ) Dental Practitioner
11 , 314 .
