Anatomical Study of Pterygospinous and Pterygoalar Bar in Human Skulls with their Phylogeny and Clinical Significance

Prevalence, morphology, and morphometry of the pterygospinous bar: a meta-analysis

“…The pooled prevalence of the complete type was 4.4%, while that of the incomplete type was 11.6%. The general tendency that the incomplete PS bar is significantly more prevalent than the complete one has been systematically reported in previous works [2,7,9,13,18,19,32].…”

“…Both primary ossification and secondary ossification are considered as possible causes of PS bar formation [7]. The former theory is based on an observation of children's skulls with still evident adjacent sutures, in which the PS bar was identified [2,30]-suggesting a hereditary nature of this anatomical variant [19]. The secondary process refers to ossification of the PS ligament, which is the thickening of the fascia between the lateral and medial pterygoid muscles, that stretches between the spine of the sphenoid bone to the upper part of the posterior border of the lateral pterygoid plate, and which increases with aging [1,2,5].…”

“…The secondary process refers to ossification of the PS ligament, which is the thickening of the fascia between the lateral and medial pterygoid muscles, that stretches between the spine of the sphenoid bone to the upper part of the posterior border of the lateral pterygoid plate, and which increases with aging [1,2,5]. This ligament may also be accompanied by an accessory PS ligament or, more rarely, it may be replaced by a muscular formation called the PS muscle, which inserts into the temporomandibular joint capsule [19,25].…”

“…Moreover, racial variations have been reported for a completely ossified PS bar, with a higher percentage of cases among Caucasians than Africans (10.7% vs 2.78%) [1]. A completely ossified PS bar may form a PS (or Civinini's) foramen [19] through which passes the medial pterygoid vessels and nerve [30].…”

“…The PS bar is often confused with the pterygoalar (PA) bar [5,26], as both bars are localized close to the foramen ovale (FO) area [9]. The PS bar may be found either below or medial to the FO, whereas the PA bar lies lateral to the FO or runs beneath it, dividing FO into two parts [19] (Fig. 4).…”