Anatomical and Clinical Evaluation of Tympanic Tegmen and Mastoid Bone with Multidetector Computed Tomography / Evaluación Anatómica y Clínica del Tegmen Timpánico y Hueso Mastoideo con Tomografía Computarizada Multidetector

SUMMARY: Tegmen level and mastoid bone thickness are important parameters of surgical risk in middle ear and mastoid region surgeries. This retrospective cohort study was conducted to provide a risk classification for the mastoid and middle ear regions. The study population comprised of 300 patients who underwent multidetector computed tomography (MDCT) for various indications. Patients with no pathology that disrupted the structure of the temporal region were included in the study. A risk classification was generated by analyzing the data obtained from mastoid and tympanic tegmen depths and the mastoid bone thickness by MDCT. The mastoid and tympanic tegmen were lower on the right side than on the left. In women, the right-sided mastoid bone thickness and mastoid tegmen were lower, and low-level tympanic and mastoid tegmen on the left and thin right mastoid bones were more common. According to the risk classifications for mastoid and middle ear region surgeries, women demonstrated a higher risk than men. In addition, as the thickness of the mastoid bone increased, the levels of the mastoid and tympanic tegmen increased. The present study provides a proper risk classification that may be helpful for preoperative risk assessment prior to middle ear and mastoid region surgery.

El nivel del tegmen y el grosor del hueso mastoideo son parámetros importantes del riesgo quirúrgico en las cirugías del oído medio y la región mastoidea. Este estudio de cohorte retrospectivo se llevó a cabo para proporcionar una clasificación del riesgo en las regiones mastoidea y del oído medio. La población de estudio estuvo compuesta por 300 pacientes que se sometieron a una tomografía computarizada multidetector (MDCT) por diversas indicaciones. Se incluyeron en el estudio pacientes sin patología que alterase la estructura de la región temporal. Se generó una clasificación de riesgo analizando los datos obtenidos de las profundidades del tegmen mastoideo y timpánico y el grosor del hueso mastoideo por TCMD. El tegmen mastoideo y timpánico estaban más bajos en el lado derecho que en el izquierdo. En las mujeres, el grosor del hueso mastoideo del lado derecho y el tegmen mastoideo eran más bajos, y eran más frecuente la presencia de tegmen timpánico y mastoideo de bajo nivel en los huesos mastoideos izquierdo y delgados en el lado derecho. Según las clasificaciones de riesgo de las cirugías de la región mastoidea y del oído medio, las mujeres presentaban un mayor riesgo que los hombres. Además, a medida que aumentaba el grosor del hueso mastoides, aumentaban los niveles del tegmen mastoideo y timpánico. El presente estudio proporciona una clasificación de adecuada de riesgo que puede ser útil para la evaluación preoperatoria del riesgo antes de la cirugía del oído medio y la región mastoidea.

A Case of Large Intradiploic Epidermoid Cyst of the Temporal Bone / 대한이비인후과학회지

Intradiploic epidermoid cysts of the skull are benign lesions that are derived from the ectodermal cells of the cranium. They are rare tumors and they represent less than 1% of all intracranial tumors. The frontal and parietal bones are the most common sites for the cysts, but the temporal bone is rarely involved. They are slowly growing tumors, and may often reach an enormous size without producing neurological symptoms. For treatment, it is important to completely remove the capsule of the cysts to avoid recurrence. Malignant transformations of the cysts, which are very rare, are generally found in cases which have repeated recurrences or infections. We present a patient with an intradiploic epidermoid cyst of the temporal bone, which is located behind the left mastoid cavity. We removed the cyst successfully through transmastoid approach.

The recovering of the radical surgery of mastoid bone by the temporal facio-musscle

95% cases of otitis mastoid were sucessfully treated by the reservation and surgery and the rest 5% cases with this were treated by many different methods aiming to management of the hollows of the radical surgery of mastoid bone according to the cause or individuals. The recovering of the partly poor epithelization in the surgical hollow reported effectively. 13 patients received a surgery in the Central Military Hospital 108 during 1987-1996 were studied. The indicators of age, gender, symptoms before receiving operation and status of the surgical hollow were used to classify the result