Praveen Mulky Shenoy1, Amith Ramos2, Bharath Shetty3, Aravind Pallipady4
BACKGROUND
Palmaris longus (PL) tendon agenesis varies from 5 % to 30 % in different ethnic
groups worldwide. Its agenesis is associated with decreased wrist grip, pinch grip,
presence of cheek dimples, difference of prevalence of agenesis with gender and
handedness and with flexor carpi superficialis tendon. Student and general
population surveys done in previous studies shows the association between these
variables. The purpose of this study was to find out the association between the
presence of cheek dimples with absence of palmaris long tendon.
METHODS
We examined 1200 medical and allied health students (600 males, 600 females)
aged 18 - 24 years to assess the incidence of palmaris longus absence and the
presence of cheek and chin dimples. The presence or absence of palmaris longus
was assessed by clinical inspection using standard tests. The effectiveness of
these’ standard tests’ is also tested along with wrist strength and pinch strength.
RESULTS
163 students had PL agenesis. One hundred and twenty-one subjects had
unilateral absence of palmaris longus (13.5 %). The tendon was absent bilaterally
in 42 subjects (3.5) 77 students had either unilateral or bilateral cheek dimples
out of 163 PL agenesis. The Mishra’s test is found to be most effective for properly
defining the PL at wrist.
CONCLUSIONS
Prevalence of absence of palmaris longus is around 13.5 %. Unilateral agenesis of
PL is 10 %. Absence of palmaris longus has strong association to presence of
cheek dimples. Up to 45 % of PL agenesis will show either unilateral or bilateral
cheek dimples. Studies on cheek dimples, panniculus carnosus are very scanty in
literature; more studies might reveal interesting correlation. The grip strength of
the wrist is unaffected due to palmaris longus agenesis; however, the pinch grip
of 4th finger with thumb appears to be certainly decreased. Mishra’s test proves
to be the best in demonstrating the PL. A radiant smile displaying the cheek
dimples, has 50 % possibility of absence of PL.
