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Objective@#To assess the depths of the anterior epitympanic recess (AER) and the sinus tympani (ST) among Filipino adults and to classify the AER and ST according to grade and type, respectively.@*Methods@#Design:Retrospective Review of CT ScansSetting:Tertiary Private Teaching Hospital Participants: Scans of 182 non-pathologic ears from patients aged 18 and above with non-pathologic temporal bones (paranasal sinus, screening sinus, temporal bone, facial and cranial) with 0.62mm cuts seen from CT scans from January 01, 2010 to September 31, 2022 were analyzed. The depths of the AER and ST were measured separately and classified according to AER grade and ST type.@*Results@#The mean depth of the AER (AER-D) was 3.64 mm (SD 1.17). No significant difference was seen between right and left ears. The AER grading of the anterior-posterior depth was found to be Grade 1 (<3mm) in 54 ears (29.7%), Grade 2 (3-5mm) in 106 ears (58.2%), and Grade 3 (>5mm) in 22 ears (12.1%). The mean depth of the sinus tympani (ST-D) was 3.30 mm (SD 0.80). Out of the 182 ears, 121 (66.5%) had Type A, 50 (27.5%) had Type B while 11 (6%) had Type C.@*Conclusion@#Majority of the AER depths measured 3-5mm while most of the sinus tympani were Type A. These hidden recesses should be separately analyzed in preoperative planning for cholesteatoma surgery in order to prepare the adequate equipment to be used and approach towards these areas thereby reducing the risk for residual cholesteatomas and recurrence.
Subject(s)
Tomography , Temporal BoneABSTRACT
Background: Anterior epitympanic recess (AER) is a small anatomical space in the epitympanum anterior to level of the head of malleus. This space has received lot of attention because of its role in cholesteatoma. Dysventilation of AER can lead to retraction pockets and cholesteatomas. Due to the advent of endoscopic middle ear surgeries the visualization of the mucosal folds and spaces have been possible for the past 2 decades. Mucosal folds and spaces play an important role in middle ear ventilation and pathologies obstructing these ventilation pathways can lead to dysventilation resulting in retraction pockets / cholesteatoma. In our study we have analysed the importance of cog with respect to dysventilation syndrome. Materials and methods: This prospective radiological study was conducted at Apollo Hospitals, BG road, Bangalore for a study period of 1 year (January 2021-January 2022). All patients who underwent high resolution CT scan (HRCT) of temporal bone were included in this study. They were divided into 2 groups (Group I & II). For group I HRCT temporal bone of 200 normal scans were included and scans with chronic otitis media, congenital anomaly, temporal bone fractures and tumors were excluded from the study. 50 HRCT temporal bone scans of chronic otitis media with squamous disease were included in group II. Results: 200 HRCT scans were included in the normative data analysis of the temporal bone. Out of 200, 133 had complete cog, 54 had incomplete cog and 13 had absent cog (Table 2). We also calculated the mean diameters of the AER, AP diameter- 4.24 ± 1.3, TD - 3.36 ± 1.05 and VD - 5.3 ± 1.94 (Table 3). Similarly, we analyzed 50 HRCT temporal bone with squamous disease 32 out of 50 had absent cog (Table 4). We also calculated the dimension of AER in diseased temporal bones (Table 5). A paired T test was conducted in order to analyze these values. Conclusion: In our study we performed a radiological evaluation of AER and cog and found that incidence of absent cog is more among individuals with squamous disease than normal individuals. Hence we advocate that absent cog can lead to horizontally oriented tensor tympani that in turn results in dysventilation. Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-023-03507-9.
ABSTRACT
OBJECTIVE: To study age-related changes in the morphology of the supratubal recess (STR) and its relationship with the Eustachian tube (ET). METHODS: Seventy randomly selected computed tomography (CT) images of non-pathological temporal bones of 49 patients were reviewed retrospectively. The patients were grouped according to age into 4 age groups: group A (0-3 years), group B (4-8 years), group C (9-18 years) and group D (19-50 years). Space analytic geometry was assessed to directly calculate the morphology of the STR and the ET. RESULTS: In normal temporal bones, the STR was mostly presented with a solitary cell in life. The length of the STR was significantly longer in group C than that in group A (P<0.05). The width of the STR was declined with age and presented with significant difference among age groups (P<0.05). No significant difference was observed in the height of the STR in whole age groups (P>0.05). The aeration of the STR was intimately related with age-related morphological changes in the ET. But the important factors influencing the aeration of the STR were not always the same in different age stages. CONCLUSION: The extended length and declined width of the STR with age were mostly related with the prolonging bony part and inwardly bending cartilaginous part of the ET in children and adolescent aged from 0 to 18 years old. In adults aged more than 18 years old, the narrowed caliber of the tympanic orifice of the ET could induce the decline in the width of the STR with age, but unfolded horizontal cartilaginous part of the ET contributed to stable length and height in aeration of the STR.