Can Wideband Tympanometry Be Used as a Screening Test for Superior Semicircular Canal Dehiscence?

OBJECTIVES: We explored whether wideband tympanometry (WBT) could be used as a screening test for superior semicircular canal dehiscence (SSCD), and obtained new WBT data (given that the test is not yet in common clinical use) on patients with SSCD. METHODS: We compared the WBT data of patients clinically and radiologically diagnosed with SSCD in our hospital between 2013 and 2018 to those of healthy volunteers. We compared the resonance frequency (RF), maximum absorbance frequency (MAF), and maximum absorbance ratio (MAR). The t-test was used for statistical analysis with the significance level set to P<0.05. In addition, we used receiver operating characteristic analysis to derive cutoff values for SSCD diagnosis in terms of sensitivity and specificity. RESULTS: Seventeen patients (four with bilateral and 13 with unilateral disease; 17 ears) diagnosed with SSCD and 27 healthy volunteers (47 ears) were included. The mean RFs of the SSCD patients and healthy subjects were 548.7 Hz (range, 243 to 853 Hz) and 935.1 Hz (range, 239 to 1,875 Hz), respectively (P<0.001). The mean MARs of the SSCD patients and healthy subjects were 89.4% (range, 62% to 100%) and 82.4% (range, 63% to 99%), respectively (P=0.005). The mean MAFs of the SSCD patients and healthy subjects were 1,706.3 Hz (range, 613 to 3,816 Hz) and 2,668 Hz (range, 876 to 4,387 Hz), respectively (P<0.001). In terms of SSCD diagnosis, a MAR above 86% afforded 81% sensitivity and 77% specificity; an RF below 728 Hz, 86% sensitivity and 81% specificity; and an MAF below 1,835 Hz, 79% sensitivity and 67% specificity. CONCLUSION: WBT may be a useful clinical screening test for SSCD. The RF and MAF were lower, and the MAR higher, in SSCD patients than in normal controls.

course of the marginal mandibular branch of the facial nerve in adult cadavers; an anatomic study

Objectives: To observe the course of the marginal mandibular branch of the facial nerve [MMBFN] and its relation to the inferior border of the mandible and facial vessels

Methods: This cadaveric study was conducted at the Department of Anatomy, Gulhane Military Medical Academy, Ankara, Turkey from April to September 2012. The 44 facial halves of 22 adult cadavers were dissected under a stereomicroscope

Results: The nerve was found to be presented by one branch [36.4%], and 2 branches [63.6%]. The distance of the nerve from the inferior border of the mandible varied from 13.06-40.08 mm, with an average distance of 21.91 mm. There were communications with buccal branch only in 2 specimens [4.6%]. All the branches of the marginal mandibular branch ran laterally to the facial artery in 43 [97.7%] of the 44 specimens. In one specimen, the 2 marginal mandibular branches ran between the facial artery and vein

Conclusion: The MMBFN can occasionally be damaged during surgeries confined to the submandibular region due to its location and anatomical variant. The most common pattern of MMBFN was nerve with 2 branches. The maximum distance between the MMBFN and the mandible was 40.08 mm. This anatomical knowledge may be useful to surgeons of the head and neck in planning incisions and procedures in the submandibular region