Incidence, number and topography of Wormian bones in Greek adult dry skulls.

BACKGROUND: Wormian bones (WBs) are irregularly shaped bones formed from independent ossification centres found along cranial sutures and fontanelles. Their incidence varies among different populations and they constitute an anthropo- logical marker. Precise mechanism of formation is unknown and being under the control of genetic background and environmental factors. The aim of the current study is to investigate the incidence of WBs presence, number and topographical distribution according to gender and side in Greek adult dry skulls. MATERIALS AND METHODS: All sutures and fontanelles of 166 Greek adult dry skulls were examined for the presence, topography and number of WBs. One hundred and nineteen intact and 47 horizontally craniotomised skulls were examined for WBs presence on either side of the cranium, both exocranially and intracranially. RESULTS: One hundred and twenty-four (74.7%) skulls had WBs. No difference was detected between the incidence of WBs, gender and age. Sutures and fon- tanelles located in neurocranium showed a higher incidence of WBs, contrariwise to orbital sutures that indicated a low incidence. WBs most commonly located in the lambdoid suture (44.6%), followed in order of frequency by the coronal suture (39.8%), asterion (21% on the left and 15.3% on the right side) and parie- tomastoid suture (15.1% on the left and 13.9% on the right side). Other sutures with WBs were the occipitomastoid, sagittal, squamosal, zygomaticosphenoid, metopic, frontonasal and frontozygomatic. Regarding the skull fontanelles, WBs were found at pterion, posterior and anterior fontanelles. CONCLUSIONS: The current study highlights a high incidence of WBs in a Greek population, indicating racial variation. The in depth knowledge of exact location, frequency and number of WBs is essential for clinicians intervening in the skull area, anthropologists and forensic surgeons investigating child abuse cases.

A morphometric anatomical and comparative study of the foramen magnum region in a Greek population.

BACKGROUND: The foramen magnum (FM), a complex area in craniocervical surgery, poses a challenge for neurosurgeons. The knowledge of the detailed anatomy of the FM, occipital condyles (OC) and variations of the region is crucial for the safety of vital structures. This study focuses on the FM and OC morphometry, highlights anatomical variability and investigates correlations between the parameters studied. MATERIALS AND METHODS: One hundred and forty-three Greek adult dry skulls were examined using a digital sliding calliper (accuracy, 0.01 mm). RESULTS: Mean FM width and length were found 30.31 ± 2.79 and 35.53 ± 3.06 mm, respectively. The commonest FM shape was two semicircles (25.9 %), whereas the most unusual was irregular (0.7 %). The OC minimum width, maximum width and length were 5.71 ± 1.61, 13.09 ± 1.99 and 25.60 ± 2.91 mm on the right, and 6.25 ± 1.76, 13.01 ± 1.98 and 25.60 ± 2.70 mm on the left side. The commonest OC shape was S-like and the most unusual was ring, bilaterally. The mean anterior and posterior intercondylar distances were 19.30 ± 3.25 and 51.61 ± 5.01 mm, respectively. The OC protruded into the FM in 86.7 % of the skulls. Variations such as a third OC existed in 5.6 % and basilar processes in 2.8 %. Posterior condylar foramina were present in 75.5 %. The gender was correlated with FM width and length, OC length, bilaterally, anterior intercondylar distance (AID) and posterior intercondylar distance (PID). The OC protrusion and existence of posterior condylar foramina were correlated. Bilateral asymmetry for OC shape was statistically significant. CONCLUSION: Our results provide useful information that will enable effective and reliable surgical intervention in the FM region with the maximum safety and widest possible exposure.

Median to ulnar nerve anastomosis: a review of the literature.

Median to Ulnar nerve anastomosis in the forearm has been shown to be of clinical significance leading to "anomalous" innervation and is correlated with misdiagnosis during the assessment of nerve lesions, injuries and Carpal Tunnel Syndrome (CTS). In 1763, Martin first described the anastomosis and Gruber next mentioning it, in 1870 thus referred to as Martin--Gruber anastomosis. Despite its long history, its nature remains unclear. Many anatomical, electrophysiological, histological and genetic studies have been published, reporting the anastomosis' frequency, citing its clinical importance and classifying it into various classes and types. Diagnosis is made mostly with electrophysiological studies whereby researchers have cited certain clues taking into consideration the asymptomatic nature of the anastomosis. The current literature on median to ulnar nerve anastomosis is reviewed, highlighting its frequency and clinical significance making an excellent tool for correct diagnosis in many clinicians.

Mandibular nerve entrapment in the infratemporal fossa.

The posterior trunk of the mandibular nerve (V(3)) comprises of three main branches. Various anatomic structures may entrap and potentially compress the mandibular nerve branches. A usual position of mandibular nerve (MN) compression is the infratemporal fossa (ITF) which is one of the most difficult regions of the skull base to access surgically. The anatomical positions of compression are: the incomplete or complete ossified pterygospinous (LPs) or pterygoalar (LPa) ligament, the large lamina of the lateral plate of the pterygoid process and the medial fibres of the lower belly of the lateral pterygoid (LPt). A contraction of the LPt, due to the connection between nerve and anatomic structures (soft and hard tissues), might lead to MN compression. Any variations of the course of the MN branches can be of practical significance to surgeons and neurologists who are dealing with this region, because of possibly significant complications. The entrapment of the MN motor branches can lead to paresis or weakness in the innervated muscle. Compression of the sensory branches can provoke neuralgia or paraesthesia. Lingual nerve (LN) compression causes numbness, hypoesthesia or even anaesthesia of the mucous of the tongue, anaesthesia and loss of taste in the anterior two-thirds of the tongue, anaesthesia of the lingual gums, as well as pain related to speech articulation disorders. Dentists should be very suspicious of possible signs of neurovascular compression in the region of the ITF.