Variations of Foramen Transversarium in Typical Cervical Vertebrae

The cardinal feature of cervical vertebrae is the foramen transversarium, which transmits the vertebral artery, its accompanying vein and a sympathetic plexus from the inferior cervical ganglion. The aim of the present study was to observe the variations in the size and shape and number of foramen transversarium of typical cervical vertebrae. The study material consisted of 176 typical cervical vertebrae of unknown sex and origin, taken from adult dried human bones present in archieve of department of anatomy. The maximum and minimum mean diameters of the foramen transversarium on the right side were 6.54 mm and 5.39 mm respectively. On the left side, the maximum and minimum mean diameters of the foramen transversarium were 6.28 mm and 5.27 mm respectively. The difference of parameters on the right & left side was statistically insignificant. In no case was the foramen transversarium absent though it was asymmetrical in two cervical vertebrae. Accessory foramen transversarium were present in 11 cervical vertebrae which were present bilaterally in 7 and unilaterally in 4 vertebrae (1 right-sided and 3 left-sided). These accessory foramina could be due of remnants of costal element or due to variations in the vertebral vessels. The anatomical knowledge of the variations in the F.T of cervical vertebrae can be of importance to the neurologists, clinicians and radiologists for proper interpretation of X-rays and CT scans. This knowledge can also play an important role in identification of the dead bodies if ante mortem radiographs of the deceased are available for comparison.

ANATOMICAL VARIATIONS OF ACCESSORY FORAMINA TRANSVERSARIA IN CERVICAL VERTEBRAE

Introduction: The cervical vertebrae are cranially placed, moveable vertebrae in the human body. The characteristic feature of these vertebrae are the presence of a Foramen Transversarium (FT) in each lateral mass. A plexus of sympathetic nerves surrounding the Vertebral Artery (VA) and Vertebral Veins (VV) passes through the FT. The variable number and size of FT may lead to clinically significant conditions.It may be due to variable course of the VA which implicates an embryological basis.Aims: The objective of the present study is to find out the incidence of accessory FT in the cervical vertebrae and its morphological and clinical significance.Material and Methods:There were 117 dried cervical vertebrae available in the Department of Anatomy of Medical Sciences Stip. They were macroscopically studied to find variations in the number of FT.Results: Out of 117 cervical vertebrae accessory FT were found in 25 vertebrae (21.3%). The accessory FT were unilateral in 15 vertebrae (12.8%) and bilateral in 10 vertebrae (8.7%). The unilateral foramina were more common than the bilateral one. The accessory FT were smaller and posteriorly placed compared to the regular FT. Conclusions: In the present study 21.3% of cervical vertebrae showed accessory FT. Among them the unilateral accessory FT was more common than the bilateral variety. The accessory foramina were mostly observed in the lower cervical vertebrae. These anatomical variations and morphology of the FT is useful in the operations involving spine surgeries. It is also of great value to the radiologists in the interpretation of X-ray films and CT-scans.

Clinical significance of accessory foramina in adult human mandible

Background: The mandible is the strongest and largest bone of facial skeleton. It consists of one horseshoe-shaped body and a pair of rami. On external surface of body in the midline there is a faint ridge i.e. symphysis menti indicating the line of fusion of two halves of mandible during development. The aim of this study is to describe the position and incidence of accessory foramina on the inner surface of the body and rami of both sides of mandible to provide simple important reliable surgical landmarks.Methods: The present study was conducted on 100 dried adult human mandibles. Bones which had deformities, asymmetries, external pathological changes and fractures were excluded from the present study.Results: In 97% cases at least one accessory foramen was observed on inner surface of mandible. The accessory lingual foramen was found to be constant finding with incidence of 81%. Frequency of infraspinous or sublingual foramen was 58%, of lateral foramen was 50% and that of accessory mandibular foramen was 39%.Conclusions: The anatomical knowledge about the common location and incidence of accessory foramina in mandible are important for surgeons and anaesthetists performing surgeries in the area around mandible. These accessory foramina transmit neurovascular bundles which provide accessory innervations to the roots of teeth. Thus proper knowledge of accessory foramina are important in relation to achieving complete inferior alveolar nerve block and for avoiding injury to neurovascular bundle passing through them.