The ossified pterygoalar ligament: an anatomical study with pathological and surgical implications

Mandibular nerve entrapment has great significance, as it may be responsible for the appearance of several neurological pathologies, such as chewing disorders, taste loss, facial or tongue paraesthesia and neuralgia. The ossified pterygoalar (Pta) bar is the result of calcification and/or ossification of the ligament extending from the pterygospinous process of the lateral pterygoid lamina to the infratemporal surface of the sphenoid bone. The ossified bar may act as the cause for this entrapment. One hundred and forty-five Greek adult dry skulls were examined for the existence of a complete or incomplete Pta bar and a relative foramen. The Pta bar appeared in 31.7% of the skulls, in total, in 4.1% completely and in 27.6% incompletely ossified. The mean sagittal and transverse diameters of Pta foramen were 3.21 ± 1.70 and 4.79 ± 1.39 mm, respectively. There was no statistical significant difference between the presence of Pta bar and the side or gender. Apart from the neurological interest, this study highlights the importance of the existence of Pta bar in neurosurgery, anaesthesiology, oral and maxillofacial surgery. The passage of the needle through the foramen ovale for the injection of anaesthetics, as a treatment for trigeminal neuralgia may not be achieved due to this anatomical obstacle. In this case, intra- or postoperative radiologic investigation may be helpful.