Francesca Vannozzi

Sternal foramina :anatomy and clinical significance

The presence of one or more sternal holes is a congenital developmental anomaly that needs to be recognized and diagnosed to prevent accidental puncture of vital organs during procedures such as sternum biopsy or acupuncture. We present two cases of this bone anomaly characterized by the presence of sternal foramina that were found during tutorials for medical students in the anatomical museum” Leonetto Comparini “of University of Siena . Measurements of the foramina were carried out using a digital caliper and was subsequently made a photographic documentation.The first case shows a sternum with multiple oval foramina: one at level of body sterni with the larger diameter of mm 4,78 and two at xiphoid process with larger diameter of 8,83 and 7,44 mm respectively.The second case is a sternum with a single oval foramen at level of the lower part of body with a diameter of 12,8mm. In the fetus sternum cartilage is formed by two bars which merge with each other towards the eighth week of gestation forming the manubrium and the body of the sternum(1).At the tenth week of gestation .the subsequent ossification of the sternum takes place from six centers of ossification. The last part of the sternum to ossify in adulthood is the xyphoid process . A partial defect in the melting of cartilage bars can cause holes to form in the sternum. The incidence is between 3.1 to 27.4% in dried sterna (2). Sternal holes are observed in the manubrium, body, and in the xiphoid process, also if a highest incidence is verifyed in the xiphoid process. The presence of sternal holes may cause during sternal puncture the accidental punture of organs retrosternal as the heart and lungs with possible tamponade or pneumothorax .Moreover knowledge of this anomaly may be important in forensic medicine. The presence of a sternum holes may be mistakenly interpreted as penetrating traumatic injuries or bullet penetration. In conclusion, the recognition of this not uncommon anatomical abnormality is important for radiologists and in clinical and forensic medicine.

Variations in the length of the styloid process and the possible consequences on muscle ligamentous systems with the mandible and the hyoid bone

The styloid process of the temporal bone has a variable length as demonstrated in studies conducted with different technique: three-dimensional computed tomography or dental panoramic three-dimensional scanning. Data on the osteometric values of the styloid process is scanty with significant length differences existing between the studies attributed to different races or ethnicities.The abnormal length can be in some cases accompanied by a set of symptoms, characterized by neck pain, dysphagia, headache, sore throat, ear pain, mandible dysfunction clinically framed in Eagle’s syndrome. We present an osteometric study on the length of the styloid process of a collection of dried skulls belonging to the museum of Anatomy “Leonetto Comparini “ at the University of Siena. All skulls came from the local psychiatric hospital. For measurement we employed a digital caliper . The data were analyzed through a free statistical software (Salstat 2) . Average and standard deviation (sd), were calculated. Univariate analysis of the length of the styloid process gave the following results: average: 27 mm ; sd : 7 mm ; normal range : average +/- 2 sd : 41-13 mm. The longest styloid process was 52 mm and the shortest had a length of 0.5 mm .In one case we discovered a skull with stylohyoid calcified ligament on one side . The styloid process was long 50 mm on the right and 70 mm on the left where is the tip calcified .An abnormal long styloid process>41 mm is present in 6% of items in our biometric study . The abnormal variations in length are put in relation to the possible anatomical change of the muscular and ligamentous structures of the styloid process by drawings of a case with a marked elongation of the styloid process.The shortening of the stylomandibular ligament that we suppose considering the distance from the angle of mandible of the tip and the possible change in direction could cause difficult in the protrusion of mandible and in mastication. The shortening of stylohyoid ligaments and muscles, could cause difficult in movement of os hyoid and in raising or lowering of larynge during swallowing.