Presence of Cheek Dimples and Absence of Palmaris Longus - An Anatomical Correlation from Dakshina Kannada, Karnataka

Abstract

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. KEYWORDS Palmaris Longus Agenesis, Cheek Dimples, Bifid Zygomaticus Major, Panniculus Carnosus, Chin Dimples