Anat Cell Biol.  2016 Jun;49(2):143-150. 10.5115/acb.2016.49.2.143.

Incidence of pterygospinous and pterygoalar bridges in dried skulls of Koreans

Affiliations
  • 1Department of Oral Anatomy, BK21 PLUS Project, School of Dentistry, Pusan National University, Yangsan, Korea. kwakhh@pusan.ac.kr
  • 2Department of Anatomy, Catholic Institute for Applied Anatomy, College of Medicine, The Catholic University of Korea, Seoul, Korea.

Abstract

Understanding of morphological structures such as the sphenoid spine and pterygoid processes is important during lateral transzygomatic infratemporal fossa approach. In addition, osseous variations such as pterygospinous and pterygoalar bridges are significant in clinical practice because they can produce various neurological disturbances or block the passage of a needle into the trigeminal ganglion through the foramen ovale. Two hundred and eighty-four sides of Korean adult dry skulls were observed to carry out morphometric analysis of the lateral plate of the pterygoid process, to investigate, for the first time among Koreans, the incidence of the pterygospinous and pterygoalar bony bridges, to compare the results with those available for other regional populations, and to discuss their clinical relevance as described on literatures. The mean of maximum widths of the left and right lateral plates of the pterygoid process were 15.99 mm and 16.27 mm, respectively. Also, the mean of maximum heights of the left and right lateral plates were 31.02 mm and 31.01 mm, respectively. The ossified pterygospinous ligament was observed in 51 sides of the skulls (28.0%). Ossification of the pterygospinous ligament was complete in four sides (1.4%). In 47 sides (16.6%), the pterygospinous bridge was incomplete. The ossified pterygoalar ligament was observed in 24 sides of the skulls (8.4%). Ossification was complete in eight sides (2.8%) and incomplete in 16 sides (5.6%). This detailed analysis of the lateral plate of the pterygoid process and related ossification of ligaments can improve the understanding of complex clinical neuralgias associated with this region.

Keyword

Pterygoid process; Sphenoid spine; Pterygospinous bridge; Pterygoalar bridge

MeSH Terms

Adult
Foramen Ovale
Humans
Incidence*
Ligaments
Needles
Neuralgia
Skull*
Spine
Trigeminal Ganglion

Figure

  • Fig. 1 Classification of the pterygospinous and pterygoalar bridges including degree of completeness. (A) Incomplete pterygospinous bridging (arrows). (B) Complete pterygospinous bridging. (C) Incomplete pterygoalar bridging. (D) Complete pterygoalar bridging. AT, articular tubercle; FO, foramen ovale; FS, foramen spinosum; LPP, lateral plate of the pterygoid process; MF, mandibular fossa; SP, styloid process.

  • Fig. 2 (A, B) Illustrations showing the morphometric items measured on the lateral plate of the pterygoid process and around structures. Written descriptions of these measurements can be found in Table 1.

  • Fig. 3 Ossified pterygospinous ligament. Incomplete pterygospinous bridges (arrows) (A) and pterygospinous foramina (arrowheads) (B) formed by complete pterygospinous bridges. FO, foramen ovale; FS, foramen spinosum; LPP, lateral plate of the pterygoid process.

  • Fig. 4 Ossified pterygoalar ligament. Incomplete pterygoalar bridge (arrows) (A) and pterygoalar foramen (arrow head) (B) formed by complete pterygoalar bridge. FO, foramen ovale; LPP, lateral plate of the pterygoid process.


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