Classification and incidence of pterion patterns of Thai skulls / Clasificación e incidencia de los patrones de pterion en cráneos de Tailandia

SUMMARY: The pterion, a landmark for neurosurgery, is the weakest part of the skull owing to relatively thin bone. Variant patterns of pterion can confuse the clinicians during diagnosis of the lateral skull fractures in emergency situations. Thedifferent pterion types of many races have been reported but not of Thais. In this study; therefore, we investigated the incidence of sutural pterion patterns on of Thai skulls. The infratemporal fossa of 110 sides from 55 dried skulls identified as Thais were observed and classified for individual pterion types. The results showed that the pterion patterns can be classified into 4 types; spheno-parietal (87.27 %), fronto-temporal (4.55 %), uni-epipteric (6.36 %), and multi-epipteric (1.82 %) types. It was found that the spheno-parietal type was dominant in males (61.81 %) than in females (25.45 %). The majority of the skulls showed bilateral symmetry (85.45 %) in all types and the unilateral ones were far less (14.55 %). In bilateral pterion incidence, the spheno-parietal type was approximately 93.61 % while the uni-epipteric type was not found. Moreover, the bilateral multi-epipteric type was found only in one female skull (2.13 %). These findings will be useful for the radiologists and the neurosurgeons concerning lateral skull fractures in emergency diagnosis.

RESUMEN: El pterion es un punto de referencia para la neurocirugía, y es la parte más débil del cráneo debido a estar conformado por hueso relativamente delgado. Los diversos patrones de pterion pueden confundir a los clínicos durante el diagnóstico de fracturas laterales de cráneo en situaciones de emergencia. Con excepción de los tailandeses, diferentes tipos de pterion se han reportado en muchas razas. hemos investigado la incidencia de diversos patrones de pterion en cráneos de Tailandia. Analizamos 110 fosas infratemporales, correspondientes a 55 cráneos secos del Noreste de Tailandia y se clasificaron de acuerdo al tipo de pterion. Los resultados mostraron que el pterion puede clasificarse en 4 tipos: esfeno-parietal (87,27 %), fronto-temporal (4,55 %), epiptérico (3,63 %) y multi-epiptérico (1,81 %). Se encontró que el tipo esfeno-parietal tuvo mayor incidencia en hombres (61,81 %) que en mujeres (25,45 %). Además, la incidencia de simetría bilateral (85,45 %) fue mayor que la unilateral (14,55 %). A nivel bilateral, el tipo esfeno-parietal fue de 93,61 %, mientras que el tipo epiptérico no se observó. Por otra parte, el tipo multiepiptérico fue encontrado bilateralmente en un solo cráneo femenino (2,13 %). Esta incidencia puede ser utilizada como un conocimiento básico para los radiólogos tailandeses sobre las fracturas laterales del cráneo en un diagnóstico de emergencia.

Aortic bifurcation: a cadaveric study of its relationship to the spine.

BACKGROUND: Vascular injuries are the main complication of the anterior approach to the lumbosacral spines. One of the key procedural steps is the identification and gentle manipulation of the aortic bifurcation to prevent the vascular injury and provide the adequate exposure during anterior lumbosacral operation. OBJECTIVE: The present study was to determine the level of abdominal aortic bifurcation in Thai cadavers. MATERIAL AND METHOD: The abdominal aortic bifurcation was studied on 187 cadavers (132 men, 55 women). The average ages of the cadavers were 67.3 +/- 0.8 years (range from 30 to 88 years). The accurate site of the abdominal aortic bifurcation was determined by the relationship of the bifurcation with the level of neighbor lumbosacral spine. RESULTS: The abdominal aorta descended and bifurcated into two common iliac arteries at the level of L4 vertebra in 131 cases (70.1%), at the fourth lumbar intervertebral disc in 23 cases (12.3%), and at the level of L5 vertebra in 33 cases (17.6%). CONCLUSION: The precise location of aortic bifurcation is useful for surgeons in the anterior approach of the lumbosacral spine to prevent harmful vascular injury.

An anatomical study of anomalous renal pedicle.

Typically, the renal pedicle is located at the renal hilum, such that the renal vein is anterior to the renal artery, which in turn is anterior to the renal pelvis. Objective: Student dissection of cadavers to observe typical anatomy and observe variations that may occur. Methods: The Gross Anatomy Laboratory, Faculty of Medicine, Khon Kaen University. Results: A total of 180 Thai cadavers were dissected in anatomical practice, during the years 1998 to 2000. Anomalous renal pedicles were found in the cadavers of a 49 year-old female and a 80 year-old male. In the female, the anomalous renal pedicle presented on both the left and right sides. Both the renal pelvises were anterior to the renal vessels. We also found supernumerary renal arteries. The male had only a right anomalous renal pedicle, in which the right renal pelvis lay anterior to the right renal vessel. Variations of the renal arteries were found in this case as well. Conclusion: These observations are important so that during surgery, care be taken in retroperitoneal operations, especially pyelolithotomy.