Anatomical study of the superficial temporal artery

ABSTRACT
Background: The temporoparietal, parieto-occipital flaps or the forehead flaps that are used in reconstructive surgery are prepared on the superficial temporal artery (STA) and its branches. For a successful surgery and a suitable flap design, adequate anatomical knowledge is needed.
Aim of the work: To study superficial temporal artery as regard its branches both frontal and parietal, their presence or absence, diameters, also relation of superficial temporal artery and its branches to important anatomical landmarks like zygomatic arch, tragus, lateral canthus of the eye also.
Materials and Methods: the red colored latex solution was injected into the external carotid artery; the STA and its branches were dissected in 28 specimens and investigated, diameters of superficial temporal artery and its branches were measured ,also its relation to important anatomical landmarks as zygomatic arch was investigated.
Results: The mean diameter of the STA at the zygomatic arch was determined as2.75±0.53 mm. It was determined as2.16±0.56 mm for the frontal branch, and as1.83±0.47 mm for the parietal branch.. There were no significant differences between the vessel diameters of the right and left sides in any subject (P>0.05). The diameters of the frontal branch were bigger than those of the parietal branch in 15 samples out of 28(53,57%) .The diameters of both the frontal and parietal branches were equal in 12 samples out of 28(42,85%) .In one specimen(3,57%),The diameter of the parietal branch were bigger than those of the frontal and parietal branches in comparison with other specimens. In addition ,the frontal branch was absent in this specimen .In 7 out 28(25%), the diameters of the parietal branch were thinner than 1.5 mm. The samples with a diameter of less 1.5 mm were defined as thin parietal branches. Three of these 7samples were observed on the left side, and the other 4 on the right side. In 4 samples out of 28 (14,28%), thin frontal branch was encountered. Thin STA was observed in 2 specimens. In 20 samples out of 28 (71.42%), the bifurcation points of the STA were over the zygomatic arch .In 7 specimens out of 28(25%), the bifurcation points of the superficial temporal artery were above the zygomatic arch .In only one sample (3,57%), bifurcation was not observed, and the STA continued only as a parietal branch (absence of frontal branch). The absence of the parietal branch was not observed. In one sample (3,57%), %),parietal branch bifurcates into 2 branches were encountered. the parietal branch went forward to the parietal tuber as the continuation of the STA. Anastomotic branches arise from the posterior aspect of this parietal branch to join similar anastomotic branches from the occipital artery .The frontal branch run forward to the forehead, parallel to the upper corner of the orbicularis oculi muscle. While it run to the frontal muscle, it came back to galea. Its perforating branches passed the deep fascia and the frontal muscle .In all samples,the zygomaticoorbital artery was absent, in these samples, many small subbranches of the frontal branch directed to the lateral region of the orbit .The anterior auricular arteries had a diameter of 1 mm or less. These branches running to the helix and tragus were observed in all samples.
Conclusions: The present study confirms the well-known variability of the superficial temporal arterial branches and the relation to the pericranial region. Knowledge concerning the arterial features of the lateral forehead region is important for the aesthetic surgeon. STA and its branches have been found to be suitable for use in microvascular anastomoses. A better understanding of the midline forehead vascularity should allow modification of reconstructive techniques and reduce postoperative complications.