Morphological study of the anatomical variations of anterior belly of digastric muscle in Brazilian cadavers.

BACKGROUND: Cases of variations in anterior belly of the digastric muscle must be carefully identified to avoid misinterpretations and assist in the correct surgical or aesthetic procedure and help in the teaching of anatomy. The aim of this study was to describe the anatomical variations of anterior belly of digastric muscle in Brazilian cadavers. MATERIALS AND METHODS: Thirty-one human heads were selected, from adult cadavers (18-80 years, 29 males and 2 females). The morphology of the anterior belly of the digastric muscle was observed, identifying the possible anatomical variations that were characterised and classified according to the amount of muscle bellies, fibre direction and place of origin and insertion. The morphometric measurements were performed using a digital calliper. To analyse the data obtained, photographic documentation, anatomical description and individual morphometric description of each muscle belly were performed. The incidence of anatomical variation was obtained in percentage (%). RESULTS: The anatomical variation of the anterior belly of the digastric muscle was present in 6 cadavers (19.31%; 1 female and 5 male). All anatomical variations presented an accessory belly to the anterior belly. However, these accessory bellies were configured differently in the location, direction of muscle fibres and in their dimensions (length and width). CONCLUSIONS: The gross anatomy of the anterior belly of the digastric muscle and their variations is important to assist in surgical procedures, pathological or diagnostic function. In addition, asymmetrical variations in the submental region must be carefully identified to avoid misinterpretations.

Foramen tympanicum prevalence in the population of Southeast Brazil: a morphological study in computed tomography scans.

BACKGROUND: The foramen tympanicum is located on the anteroinferior region of the external acoustic meatus and posteromedial to the temporomandibular joint in children between the 1st and the 5th year of life. It is considered an anatomical variation when it persists in adults. The aim of this study was to verify the prevalence as well as to characterise the foramen tympanicum in computed tomography (CT) scans of the population from southeastern part of Brazil. MATERIALS AND METHODS: A total of 78 CT scans of dry human skulls (20 female and 58 male) were used, which were selected randomly regarding the ages, ranged from 15 to 100 years. The foramen tympanicum was identified in the images of the axial plane and confirmed in the images of the coronal and sagittal planes. The largest diameter (in mm) was obtained. The descriptive statistics (in %), Fisher's test and χ2 test were performed to compare the prevalence of foramen tympanicum between sexes and sides. The probability value ≤ 0.05 was defined as a level of significance. Descriptive statistics were performed to verify the mean diameter of the foramen on the right and left sides of the skulls. RESULTS: The prevalence of foramen tympanicum was higher in females (p = 0.0070), bilaterally, as the absolute values of females were lower in relation to males. Fisher's exact test showed that the prevalence of foramen tympanicum was significantly higher in females (45%) than in males (15.52%). On the right side, the mean axial diameter was 2.23 mm (range 0.93-3.75 mm). On the left side, the mean axial diameter was 2.22 mm (range 0.9-3.61 mm). CONCLUSIONS: The knowledge of anatomical variations is extremely valuable for an accurate diagnosis, treatment plan and prognosis and a thorough preoperative assessment.

Trigeminal neuralgia: literature review

The trigeminal nerve, fifth equal of cranial nerves, a mixed nerve is considered by possessing motor and sensitive components. The sensitive portion takes to the Nervous System Central somesthesics information from the skin and mucous membrane of great area of the face, being responsible also for a neural disease, known as the Trigeminal Neuralgia. The aim of this study was to review the literature on the main characteristics of Trigeminal Neuralgia, the relevant aspects for the diagnosis and treatment options for this pathology. This neuralgia is characterized by hard pains and sudden, similar to electric discharges, with duration between a few seconds to two minutes, in the trigeminal nerve sensorial distribution. The pain is unchained by light touches in specific points in the skin of the face or for movements of the facial muscles, it can be caused by traumatic sequels or physiologic processes degenerative associate the vascular compression. Prevails in the senior population, frequently in the woman. In a unilateral way it attacks more the maxillary and mandibular divisions, rarely happens in a simultaneous way in the three branches of trigeminal nerve three branches.

Morphological characteristics of foramen of Vesaliusand its relationship with clinical implications

The aim of this study was to evaluate the incidence as well morphometry of the foramen of Vesalius in humanskulls and analyzing their clinical importance. Dry human skulls (n = 80) and with gender distinction wereused (40 male and 40 female). The results demonstrates an total incidence of 40%, 13.75% skulls with thebilateral presence of the foramen, 26.25% skulls with the unilateral presence of the foramen, 31.25% skullswith foramen only of the right side, 22.50% skulls with foramen only of the left side, 25% masculine skulls withat least 1 foramen and 52.25% skulls with at least 1 foramen. The morphometry showed an average diameterof 1.457 ± 1.043 mm on the right and 1592 ± 0938 mm to the left. The average distance to the foramenovale was 1.853 ± 0.303 mm on the right side and 2.464 ± 0.311 mm on the left. It can be concluded that adeepened anatomical study of the foramen of Vesalius collaborates not only for anatomical knowledge of thisstructure, but also in clinical situations involving this foramen.

Incidence of the ossified pterygoalar ligamentin Brazilian human skulls and its clinical implications

The ossified pterygoalar ligament is formed between the lateral lamina of the pterygoid process and theinfratemporal surface of the sphenoid bone or its greater wing and was not connected to the sphenoid spine.The aim of this study was to evaluate the incidence of the ossified pterygoalar ligament in Brazilian humanskulls and analyzing its clinical importance. 183 Brazilian adult (between 30 to 60 years old) dry human skullswere evaluated. Was evaluated the incidence of skulls with complete or partial ossification of the pterygoalarligament, bilaterally and unilaterally and in the presence on the right and left sides. Were found 5 skulls had theossified pterygoalar ligament, resulting in an overall incidence of 2.73%. There was 1 skull in the presence ofthe incomplete ossification of the pterygoalar ligament, unilaterally and on the left side resulting in incidence of0.54%. There were 4 skulls in the presence of the complete ossification of the pterygoalar ligament, unilaterallyand on the right side resulting in incidence of 2.18%. The ossified pterygoalar ligament is a major cause of theentrapment of the lingual nerve or a branch of the mandibular nerve and may cause mandibular neuralgia. Theincidence of the ossified pterygoalar ligament and the pterygoalar foramen is low in the Brazilian population.However, these structures have clinical significance as this ligament establish relationships with the ovaleforamen and difficulty in accessing in this foramen in a therapeutic approach.