Variation and incidence of agenesis of the pyramidalis muscles in Nigerian males

Abstract

In recognition of the variations in occurrence, shape and size of the pyramidalis muscle in different races, sexes and nationals and its relevance in flap and graft, this study was carried out to determine the incidence of its agenesis, variation in occurrence, shape and mean values of length and breadth in Nigerian males. A total of 24 male cadavers from the Anatomy Laboratories of different Nigerian Universities were used in this study. Dissection of the lower anterolateral abdominal wall was made to ascertain the presence, shape and size of the muscle. Agenesis occurred in 8.33% of the subjects studied. There was no case of unilateral occurrence or  supernumerary presence and the predominant shape was triangular with no difference in shape on either side. The mean values of the length and the breadth for the right pyramidalis muscle were 8.09 0.70 and 1.55 0.28, while the mean values of 7.94 1.71 and 1.6 0.30 were recorded for the left. These differences were found not to be statistically significant (P> 0.05). Our findings suggest that the incidence of agenesis of the pyramidalis muscle in Nigerian males is not common and there are no significant differences in the sizes of the muscle on either size.