Evaluation of styloid process by three-dimensional computed tomography.

The purpose of this paper was to investigate the length, medial angulations and other structural variants of the styloid process (SP) by three-dimensional computed tomography (3D CT) in patients without any complaints related to elongated SP. We performed temporal computed tomography (CT) scans in 138 cases (87 males, 51 females) with a mean age of 34.5 (17-86). The structure, length and medial angulation of SPs were evaluated on 3D reconstructed images. SP lengths varied between 1.58 and 5.48 cm (average length 2.83 cm), and the angles varied between 60.6 and 84.1 degrees (average angle 69.4 degrees). Other morphological findings were absence of SP (3 unilateral and 1 bilateral), ossification of stylohyoid ligament (9 unilateral and 27 bilateral), irregular SP (5 unilateral and 5 bilateral), fragmentation of SP (12 unilateral and 9 bilateral), absence of the proximal part (5 unilateral and 9 bilateral) and double proximal part (1 unilateral). According to our results, we propose a new classification. Absence of SP, absence of the proximal part of SP, duplication of the proximal part of SP and angle values of SP have never been reported before according to the available medical literature. 3D CT is an effective method in the evaluation of the SP length, angulations and other morphological characteristics.