title: Foramen of civinini: a new anatomical guide for maxillofacial surgeons.
abstract: BACKGROUND
  Study on Morphometric and radiological aspect on existence of foramen of civinini. Sphenoid bone comprises of some rare ossified ligaments, may encounter difficulty in surgical procedures. Incidence of Pterygospinous bars various with different racial groups and they are genetically controlled. Complete ossification of pterygospinous ligament form foramen of civinini. Entrapments of vessels or nerves may occur due to existence of pterygospinous bar. The bar may locate medially or inferiorly to formen ovale as seen in Hawaiian and lemurs. Co - existence of bar with the wide lateral pterygoid plate exhibits development of the bar from herbivore, carnivore and old world monkeys. Comparatively absence or small spine of civinini noted in new world monkeys, rodents and platyrrhines. Pterygospinousbar represents the phylogenetic remnant of Human beings.
  
  
  METHODS
  By using digital vernier caliper, the measurements of length, width of the pterygospinous bar and area of foramen of civinini including the length and breadth of lateral pterygoid plate were measured. Using X rays the radiological view was determined.
  
  
  RESULTS
  In this study from 160 cases of skull and sphenoid bones revealed that complete and incomplete foramen of civinini in 1.25% and 7.5% of cases respectively. Peculiarly accessory foramen of civinini noticed in 1.25% of cases. Maximum area of foramen of civinini was 94.2mm(2). The maximum width of lateral pterygoid was noted as 19.6mm respectively. Mentocoronal view of skiagram clearly shows the bar.
  
  
  CONCLUSIONS
  During Anaesthesia for trigeminal neuralgia may encounter difficult to pass the needle. The bar compress the mandibular nerve branches can cause lingual numbness, pain and speech impairment. Conductive anaesthesia on the mandibular nerve through the lateral subzygomatic route may be difficult to approach. Exploring the anatomical and clinical updates of pterygospinous bar may guide the surgeons and radiologists to overcome any difficulties in infratemporal and para or retropharyngeal regions.
authors.affiliation: Tutor, Department of Anatomy, Chettinad Hospital and Research Institute , Rajiv Gandhi Salai, OMR, Kelambakkam Chennai 603103, India .
authors.forename: R Sharmila
authors.initials: RS
authors.lastname: Saran
authors.forename: K Suba
authors.initials: KS
authors.lastname: Ananthi
authors.forename: Aruna
authors.initials: A
authors.lastname: Subramaniam
authors.forename: Ms Thotakura
authors.initials: MT
authors.lastname: Balaji
authors.forename: D
authors.initials: D
authors.lastname: Vinaitha
authors.forename: G
authors.initials: G
authors.lastname: Vaithianathan
keywords: Mandibular nerve entrapment; Ossification; Phylogeny; Pterygospinous bar; Radiology