Lateral Canal Research Articles

Vestibulo-ocular reflex evaluation of the children with acquired esotropia

ObjectivesThis study aims to evaluate the effects of acquired esotropia on vestibulo-ocular reflex (VOR) gain in children using video (vHIT) and functional head impulse (fHIT) tests. MethodsA total of 62 children aged 6–18 years, with acquired esotropia and normal vision, were evaluated in the study. The patients were divided into two sub-groups: accommodative and non-accommodative. VOR gains were analyzed by performing lateral canal vHIT and fHIT with monocular and binocular recordings by a single examiner. ResultsSeventeen (10 male, 7 female) children with accommodative esotropia, 24 (14 male, 10 female) children with non-accommodative esotropia, and 21 (8 male and 12 female) healthy controls were included in this study. The vHIT findings did not differ between the groups (p˃.05). In the non-accommodative esotropia group, the location of the camera in both binocular and monocular vHIT recordings made a significant difference in the left VOR gain (p = .025, z = −2.243, p = .032, and z = −2.143, respectively), but no difference was observed in the right VOR gain. In the accommodative esotropia group, while the camera was on the left there was a significant difference in the right VOR gain between binocular and monocular recordings (p = .016, z = −2.413) but no difference was observed in the left VOR gain. No overt or covert saccade was detected in any group. ConclusionsThe statistical differences found in vHIT and fHIT in acquired esotropia patients are thought to be sporadic and based on the results of this study no correction or change in recording technique is required for vHIT or fHIT in children with acquired esotropia.

Vestibular semicircular canal function as detected by video Head Impulse Test (vHIT) is essentially unchanged in people with Parkinson’s disease compared to healthy controls

BACKGROUND: Parkinson’s disease (PD) is a common multi-system neurodegenerative disorder with possible vestibular system dysfunction, but prior vestibular function test findings are equivocal. OBJECTIVE: To report and compare vestibulo-ocular reflex (VOR) gain as measured by the video head impulse test (vHIT) in participants with PD, including tremor dominant and postural instability/gait dysfunction phenotypes, with healthy controls (HC). METHODS: Forty participants with PD and 40 age- and gender-matched HC had their vestibular function assessed. Lateral and vertical semicircular canal VOR gains were measured with vHIT. VOR canal gains between PD participants and HC were compared with independent samples t-tests. Two distinct PD phenotypes were compared to HC using Tukey’s ANOVA. The relationship of VOR gain with PD duration, phenotype, severity and age were investigated using logistic regression. RESULTS: There were no significant differences between groups in vHIT VOR gain for lateral or vertical canals. There was no evidence of an effect of PD severity, phenotype or age on VOR gains in the PD group. CONCLUSION: The impulsive angular VOR pathways are not significantly affected by the pathophysiological changes associated with mild to moderate PD.

Microsurgical Anatomy of the Petrous Part of the Temporal Bone

For a surgeon to become skilled at skull base surgery, they should have mastered the three-dimensional anatomy of the petrous part of the temporal bone. The anatomy encountered during surgery is demonstrated from the superior, posterior, and lateral aspects of the petrous bone. The landmarks of the superior aspect of the petrous bone are the third division of the trigeminal nerve, the petrous ridge, the arcuate eminence, the greater superficial petrosal nerve, and the internal carotid artery. Drilling of the rhomboid area surrounded by these structures results in the exposure of the internal auditory canal and the posterior fossa dura. A key landmark of the posterior surface of the petrous bone is the dural fovea which marks the apex of the endolymphatic sac. After a dura flap is raised in a "U" shape just beyond the fovea, the internal auditory canal is opened to resect an intacanalicular portion of a vestibular schwannoma. Mastoidectomy is then performed from the lateral aspect of the petrous bone. Drilling of the mastoid leads to the exposure of the sigmoid sinus, mastoid antrum, fallopian canal, and lateral semicircular canals. Knowledge of the precise surgical anatomy of the petrosal bone is required to perform safe and secure skull base surgery.

Root canal anatomy and morphology of permanent maxillary Lateral Incisors in an Iranian population

A meticulous knowledge of the root canal anatomy and morphology of the teeth is imperative to achieve successful root canal and also many other dental and surgical treatments on them. The purpose of this study was to study the root canal anatomy and morphology of permanent maxillary Lateral incisors in Kerman. 100 extracted intact permanent maxillary Lateral incisor teeth were collected from different dental clinics in Kerman. The anatomic and morphologic characteristics of the selected samples such as the number of roots, the apical root curve direction and the length of the teeth were determined by macroscopic evaluation and length assessment of each sample. After staining, decalcification and clearing of each tooth the existence and location of additional and lateral canals was also carefully explored by using magnifying tools. All maxillary Lateral incisors had just one root and one root canal and the average length for this tooth was 22.5 mms in this study. The curvature of the roots in 67% of the samples was distally, in 5%; bucally, in 2%; palatally and in 3%; mesially. 23% of the teeth had straight roots and root canals. Also, 29% of the teeth had lateral canals that in 89% of the cases were located in the apical thirds, in 11%; in the middle and in none of the cases in the coronal thirds. As a conclusion lateral canals and curved apex which are thorough challenges in dentistry are prevalent in maxillary lateral incisors among this south eastern Iranian population.

Comparative study of Chronic Ulcerative Dermatopathy in cultured meagre, Argyrosomus regius

Chronic Ulcerative Dermatopathy (CUD) is a disease that affects all cultured meagre when reared in facilities supplied with borehole water, resulting in ulceration of the skin overlying the lateral line canals. The aims of this study were (i) to describe the morphogenesis of the cephalic lateral line, (ii) to investigate the effect of the use of borehole water vs natural seawater in the development of the disease, (iii) to assess the recovery of the lesions and (iv) to evaluate the effect of CO2 and pH on the development of CUD. The development of the lateral line canals in the head was completed by day 28 post hatching when fish were 19.3 mm in total length, while the source of the water did not affect the developmental process. The characteristic lesions of CUD were induced when meagre were reared in borehole water, while the lesions were resolved when fish were transferred to natural seawater. Lesions were macroscopically visible by day 56 post hatching. Moreover, significant differences in the expression of genes regulating osteoclast's activity were observed between healthy and CUD-affected fish, while neither pH nor CO2 were involved in the development of the disease. Finally, higher concentrations of heavy metals were found in the heads of CUD-affected meagres reared in borehole water compared to healthy fish reared in natural seawater.

Lateral semicircular labyrintine fistula

Labyrinthine fistula (LF) is a well-known complication of chronic otitis media with cholesteatoma. The most common location of the LF is in the area of the lateral semicircular canal, but it can also affects other semicircular canals and in rare cases the cochlea. The treatment of LF has been discussed in the literature by various authors and is still debatable. Hearing preservation is an important goal of labyrinthine fistula treatment. The appropriate management of LF depends on factors like hearing condition of both ears, the extent of the disease and the intraoperative size of the fistula. Sometimes the disease induced changes can’t be detected radiologically or diagnosed clinically preoperatively. Such cases surprise the surgeon during intraoperative period and can be very challenging.

Asymptomatic unilateral lateral semicircular canal aplasia associated with a dilated vestibule

<p class="abstract">Lateral semicircular canal aplasia is a rare form of vestibular dysplasia. This is the last canal to be formed during the fetal period, becoming susceptible to isolated malformations. A 17-year-old male patient performed a magnetic resonance with a subsequent incidental finding of isolated, unilateral, lateral SCS aplasia associated with a dilated vestibule. He was asymptomatic and physical examination was unremarkable. Videonistagmography showed a diminished ipsilateral caloric response and ipsilateral v-HIT gains were normal. To the best of our knowledge, this is the first non-syndromic case of aplasia of the lateral SCS with no vestibular or audiological symptoms. This absence could be explained by compensation due to the congenital nature of this malformation.</p><p> </p>

Immediate repeated testing (IRT) for BPPV: A cost-effective examination.

ObjectiveTo show that a negative Dix‐Hallpike test or Pagnini‐McClure test may convert into positive after head shaking in cases of semicircular canalith jam.MethodsThis is a retrospective study, where 768 cases of BPPV were studied of which 36 were found to have canalith jam.ResultsThirty‐six patients (4.7%) presented with canalith jam; 4.8% of posterior canal BPPV and 3.7% of lateral canal BPPV were attributed to canalith jam.ConclusionImmediate repeated testing for BPPV allows us to identify undiagnosed cases of BPPV where canalith jam has occurred. It is a cost‐effective technique that provides benefits for clinicians, patients, and the healthcare system.

Diagnostic Accuracy of High-resolution Computed Tomography (HRCT) Temporal Bone in the Evaluation of Chronic Suppurative Otitis Media

Chronic suppurative otitis media is a disease presented with recurrent purulent discharge through perforated tympanic membrane. Other clinical presentation varies form variable hearing loss, tinnitus, vertigo according to extent and complication of disease. Cholesteatoma is most common association of CSOM, and is characterized by presence of keratin and other desquamated tissue covered by squamous epithelium. Diagnosis of CSOM is readily made by otorhinolaryngologist with otoscopy or oto-endoscopy, though extent of disease can be evaluated through HRCT temporal bone or MRI of middle and inner ear. HRCT temporal bone is now widely acceptable as investigation of choice for evaluation of CSOM as it has high efficacy to detect bony erosion. The present study is conducted over 73 patients in the department of radiodiagnosis, Dr. S.N. medical college, Jodhpur, Rajasthan over a period between 2020 to 2021 with the aim to evaluate the diagnostic efficacy of HRCT temporal bone to identify presence and extension of disease, alteration of mastoid aeration, bony and ossicular erosion with the comparison of intraoperative findings in the form of sensitivity, specificity, positive and negative predictive value. In this study 44 patients(60%) were male, mean age of presentation is 30.52 ± 9.70 years. Common clinical presentation was ear discharge (91.8%) and hard of hearing(64%). presence of soft tissue density is most consistent finding present in 71(97.3%) patients, alteration of aeration of mastoid is observed in 67 (91.8%) patients, erosion of incus in frequent followed by maleus and stapes. Facial canal and lateral semicircular canal erosion is less common observation. The study concluded that HRCT temporal bone is reliable and evidentiary diagnostic tool in identifying the presence of disease, ossicular erosion, and detecting complication following CSOM.
 Keywords: Cholesteatoma, Ossicular erosion, Facial canal dehiscence, Lateral semicircular canal dehiscence

A New Family of Galeaspids (Jawless Stem‐Gnathostomata) from the Early Silurian of Chongqing, Southwestern China

AbstractA new genus and species of agnathan Eugaleaspidiformes (Galeaspida), Yongdongaspis littoralis gen. et sp. nov., is described from the Llandovery (lower Silurian) Huixingshao Formation at Yongdong Town, Xiushan County, Chongqing, southwestern China. This new Telychian taxon morphologically exhibits some transitional states between Sinogaleaspidae and a cluster of higher eugaleaspidiforms containing Tridensaspidae, Eugaleaspidae, Yunnanogaleaspis, and Nochelaspis, which we term here as the ‘eugaleaspid cluster'. Phylogenetic analysis of an extended character matrix of Galeaspida reveals Yongdongaspis, on which Yongdongaspidae fam. nov. is erected, as the sister taxon of this ‘eugaleaspid cluster', supported by two synapomorphies, the presence of one median transverse canal, and two lateral transverse canals leaving from the infraorbital canal. As the first fish described from the Llandovery Huixingshao Formation in Chongqing, Yongdongaspis provides new fossil evidence for the subdivision and correlation of the Upper Red Beds in South China.

Filling Ability of Various Root Canal Sealers into Simulated Lateral Canals

Background: This study aimed to assess and compare the depth of penetration of TotalFill BC, AH Plus Jet, and GuttaFlow Bioseal sealers into simulated lateral canals. Materials and Methods: A total of 30 extracted mandibular premolars were selected. Simulated lateral canals were made. The specimens were randomized into three experimental groups of 10 each. The specimens were cleared for visualization under a stereomicroscope at 10× magnification. The depth of penetration was assessed by a four-grade scoring system. Data were submitted to Fisher exact test at 5% significance. Results: There was statistically no significant difference among the experimental groups regarding the depth of penetration (P > .05). Conclusion: All root canal sealers experimented with herein showed a comparable depth of penetration in the simulated lateral canals regarding their filling ability.

INICIOS DE LA CIRUGÍA ENDOSCÓPICA DE COLUMNA EN EL PERÚ

In recent years, spinal endoscopy has become increasingly common in our setting; however, its use is not recent. The first reported cases date back to the early 2010s by a team from the Cayetano Heredia Hospital in charge of Drs. Wesley Alaba and Jerson Flores. Although other minimally invasive procedures such as nucleoplasty, nucleolysis, or percutaneous rhizotomies had already been used since the 2000s, it was not until 2011 that endoscopy was used for the first time in a standardized manner in spinal surgery with the endoscope as the only element of vision, successfully resecting a vertebral lesion. The first cases of vertebral pathology in which endoscopic surgery was used were the resection of a synovial cyst and a tuberculous abscess, followed by the resection of herniated discs at the L5-S1 level and later at the L3-L4 and L4-L5 levels. The first approach was the tubular interlaminar posterior approach, followed by the transforaminal endoscopic approach and the percutaneous posterior interlaminar approach. In the following years, endoscopy has been used not only in resecting herniated discs but also in treating central and lateral canal stenosis, reaching significant experience in this technique. The development of spinal endoscopy and its increasingly widespread use by neurosurgeons and traumatologists from different hospitals in the country represents an important advance in spinal surgery in Peru, which brings greater benefit to patients. Keywords: Endoscopy, Intervertebral Disc Displacement, Endoscopes, Neurosurgeons (source: MeSH NLM)

Реконструктивно-пластичні операції з відновлення прохідності при різних рівнях субтотальної резекції ободової кишки в дітей з агангліозом кишечника

Subtotal resection of the colon in intestinal agangliosis depends on the level of lesion and secondary decompensatory changes in the intestinal wall. Rational choice of reconstructive plastic surgery in such pathology is necessary to restore patency, normalize functional changes in the intestine and stabilize the general condition of patients. Purpose - to evaluate the results of reconstructive-plastic surgery to restore patency at different levels of subtotal resection of the colon in children with intestinal agangliosis. Materials and methods. We analyzed the surgical treatment of 182 children with intestinal agangliosis aged from 1 month to 8 years, who underwent reconstructive-plastic surgery to restore patency at different levels of subtotal resection of the colon. Results. In 58 (31.86%) patients after subtotal resection of the colon performed the pullthrough of the remaining segment of the colon on the left mesenteric sinus (lateral canal), in 51 (28.02%) - pullthrough of the remaining segment of the colon on the right mesenteric sinus in front of the terminal ileum, in 63 (34.62%) - pullthrough of the ascending colon or caecum on the right flank with a rotation of 180° and in 10 (5.50%) children - replacement of the left half of the colon with an ileograft with intrarectal pullthrough. In 161 (88.46%) cases good results were obtained, and in 21 (11.54%) patients - satisfactory functional results in the long term follow up. Conclusions. Restoration of intestinal patency after subtotal resection of the colon in children with intestinal agangliosis should be aimed at providing favorable conditions for anastomosis between the remaining part of the colon and rectum. If it is impossible to directly anastomose the remaining segments of the colon and rectum, it is advisable to replace the left half of the colon with an ileograft with its intrarectal pullthrough. Differential approach in the choice of reconstructive plastic surgery for subtotal resection of the colon allows to normalize functional changes in the intestine and stabilize the general condition of patients. The research was carried out in accordance with the principles of the Helsinki declaration. The study protocol was approved by the Local ethics committee of all participating institutions. The informed consent of the patient was obtained for conducting the studies. No conflict of interest was declared by the authors. Key words: agangliosis, intestine, children, surgical treatment, results.

The Effect of the Ultrasonic Irrigant Activation Protocol on the Removal of a Dual-species Biofilm from Artificial Lateral Canals

IntroductionLateral canals are particularly challenging to clean and disinfect. The aim of this study was to compare the removal efficacy of a dual-species biofilm from a lateral canal model by different ultrasonic irrigant activation protocols in vitro. MethodsArtificial root canal models with 270 simulated lateral canals were made of polydimethylsiloxane. A dual-species biofilm (Streptococcus oralis and Actinomyces naeslundi) was grown in vitro in the lateral canals using a constant depth film fermenter. Two percent NaOCl or demineralized water was delivered by a syringe and an open-ended needle for 30 seconds and subsequently activated by an ultrasonic file for a total activation time of 30, 60, or 90 seconds divided in 1 or 3 consecutive activation cycles. In the control groups, the irrigant was allowed to rest for 30, 60, or 90 seconds. The volume of the biofilm in the lateral canal was evaluated before and after the final irrigation protocol by optical coherence tomography. The results were analyzed by 3-way factorial analysis of variance (α = 0.05). ResultsIrrigation with NaOCl rather than demineralized water resulted in more effective biofilm removal from the lateral canal (P < .001). Three cycles of intermittent ultrasonic activation were significantly more effective than no activation (P = .029). The total irrigant contact time did not affect biofilm removal (P = .403). ConclusionsThe type of the irrigant and the ultrasonic activation protocol affected biofilm removal from artificial lateral canals. None of the compared protocols was able to eradicate the biofilm.

Auto-Pattern Recognition for Diagnosis in Benign Paroxysmal Positional Vertigo Using Principal Component Analysis: A Preliminary Study

Objectives: The aim of this study was to develop a filtering algorithm for raw nystagmus images and a diagnostic assistive algorithm using a principal component analysis (PCA) to distinguish the different types of benign paroxysmal positional vertigo (BPPV).Methods: Fifteen video clips of clinical data with typical nystagmus patterns of BPPV (13 cases) and with normal nystamgmus (two cases) were preprocessed when applied the thresholding, morphology operation, residual noise filtering, and center point extraction stages. We analyzed multiple data clusters in a single frame via a PCA; in addition, we statistically analyzed the horizontal and vertical components of the main vector among the multiple data clusters in the canalolithiasis of the lateral semicircular canal (LSCC) and the posterior semicircular canal (PSCC).Results: We obtained a clear imaginary pupil and data on the fast phases and slow phases after preprocessing the images. For a normal patient, a round shape of clustered dots was observed. Patients with LSCC showed an elongated horizontal shape, whereas patients with PSCC showed an oval shape at the (x, y) coordinates. The scalar values (mm) of the horizontal component of the main vector when performing a PCA between the LSCC- and PSCC-BPPV were substantially different (102.08±20.11 vs. 32.36±12.52 mm, respectively; &lt;i&gt;p&lt;/i&gt;=0.0012). Additionally, the salar ratio of horizontal to vertical components in LSCC and PSCC exhibited a significant difference (16.11±10.74 mm vs. 2.61±1.07 mm, respectively; &lt;i&gt;p&lt;/i&gt;=0.0023).Conclusions: The data of a white simulated imaginary pupil without any background noise can be a separate monitoring option, which can aid clinicians in determining the types of BPPV exhibited. Therefore, this analysis algorithm will provide assistive information for diagnosis of BPPV to clinicians.

Inner Ear Anomalies in Children With Apert Syndrome: A Radiological and Audiological Analysis.

Apert syndrome is a multisystem genetic disorder typically characterized by craniosynostosis and syndactyly. Studies also report an increased incidence of hearing loss in children with Apert syndrome in comparison to the general population. The aim of this study was to gain an understanding of the inner ear radiological anatomical variations seen in children with Apert syndrome and correlate these with audiological outcomes. This was a retrospective review of computed tomography imaging of patients with Apert syndrome. Radiological images were examined for anatomical variations in inner ear structures. These were correlated with audiological testing. Nineteen patients were included in the study. The most commonly observed anomaly was an absent bony window of the lateral semi-circular canal (SCC) in 11 patients (58%), followed by an enlarged lateral SCC in 12 patients (63%). This combination of anomalies was seen collectively in 42% of patients and together these give the appearance of a 'rectangular vestibular cavity'. Audiological results were available in 11 patients and 9 of these patients had a conductive hearing loss. To the authors' knowledge, this is the first study that reports radiological findings alongside audiological testing in Apert syndrome and describes the appearance of a 'rectangular vestibular cavity'.

Video Head Impulse Test in Persons with Blindness: Feasibility and Outcomes

To achieve balance, persons with blindness (PWB) use proprioceptive and vestibular cues rather than the visual system; however, PWB are equally susceptible to acquire vestibular disorders. Reliable assessments of the vestibular system in PWB are essential to determine the presence or absence of vestibular disorders. The saccular and the utricular functioning can be assessed using cervical vestibular-evoked myogenic potential and ocular vestibular-evoked myogenic potential, respectively. Evaluation of the functional integrity of the semicircular canals requires an assessment of the vestibular ocular reflex; however, this can be challenging in PWB. Video head impulse test (vHIT) assesses the vestibular ocular reflex (VOR) elicited against the natural high-frequency head movement in the planes of all six semicircular canals. This study aimed to explore the feasibility and outcomes of administering vHIT in PWB. Standard (static) groups comparison. Nineteen young PWB and 23 age-matched adults with "normal" vision (control group) were included in the study. PWB underwent vHIT once, while the control group was tested in three conditions; condition 1 was used to simulate blindness for the control group, where vHIT was done in a pitch-dark room without prior instructions; condition 2 included vHIT testing in daylight, without a fixed visual target and any instructions; and condition 3 involved vHIT in daylight in the presence of a set visual target and with standard instructions to maintain visual focus on the visual target. The VOR gain was abnormal in the PWB group for all the canals. Among the PWB, the lateral canals (mean = 0.63) had the best VOR gain, followed by the anterior canals (mean = 0.53) and the posterior canals (mean = 0.31). In the control group, the VOR gain was significantly reduced in condition 1. There was no significant difference between the VOR gain in the PWB group and the control group in condition 1 for the lateral and the anterior canals. A higher proportion of participants in the PWB group had the presence of refixation saccades. VOR is significantly reduced in PWB but not completely absent. There may be a need to develop normative data for blind individuals to decide whether or not a person with blindness has a vestibular dysfunction, specifically a VOR deficit.

Video Occulography-Assisted Diagnosis of BPPV and Comparison of Pre- and Post-Intervention Dizziness Handicap Inventory Score

AbstractBenign paroxysmal positional vertigo (BPPV) is a commonly recognized vestibular disorder which is characterized by brief periods of vertigo and a characteristic nystagmus. The nystagmus is often difficult to appreciate with naked eyes and hence video oculography is a helpful tool. Dizziness Handicap Inventory is an objective way to assess the impact of vertigo on quality of life. Objective Our study here aims at diagnosing undiagnosed, difficult and missed cases of BPPV using video-oculography and managing it with repositioning manoeuvre. This study also aims at measuring Dizziness Handicap Inventory Scores pre and post repositioning manoeuvre. We also observed the association between Vitamin D levels and the occurrence of BPPV. Methods and Materials One hundred and twenty-six patients were enrolled in the age group of 18-70 years. After recognizing patients with BPPV, vertigo evaluation was performed. Those patients with suggestive history and suspicion of multiple canal involvement were taken for video-oculography. Results Forty-four patients were in age group of 50-60 years, having female predominance. 35.71% cases which were missed on clinical examination were correctly diagnosed using video-oculography. The mean pre-intervention DHI was 41.29 ± 15.90 which lowered down to 14.84 ± 11.52 in post-intervention period. The highest DHI scores were seen in multi-canal BPPV involving lateral and posterior semi-circular canals. Conclusion With the help of vide-oculography we could diagnose more cases of anterior and multi canal BPPV which are often missed. Maximum number of participants had insufficient levels of Vitamin-D and in our opinion correcting it would reduce the occurrence and recurrence rate..

Practical approach for lateral canal benign paroxysmal positional vertigo

Benign paroxysmal positional vertigo (BPPV) of the lateral semicircular canal is a well-recognized condition, even though there are controversies about the repositioning maneuvers and their efficacy. In recent decades, several maneuvers have been proposed for treating both apogeotropic and geotropic variants of lateral canal BPPV. Our purpose is to discuss a practical approach to this pathology with the Zuma maneuver. In a single session, this maneuver may be useful to treat patients with canalithiasis of the ampullary and non-ampullary arms, and cupulolithiasis with the otoliths in the canal and utricular side of the lateral canal.

Evaluation of the Relationship Between Facial Nerve and Lateral Semicircular Canal in the Posterior Tympanotomy Approach.

Background : To clinically and radiologically evaluate the relationship between the facial nerve and the lateral semicircular canal during posterior tympanotomy.Methods: Patients who received cochlear implants between 2010 and 2020 were included in the study. The relationship between the facial nerve and the lateral semicircular canal was classified into 3 types by evaluating the axial section computed tomography images. If the facial nerve passed medially without contacting the lateral semicircular canal dome, it was classified as type 1; if the facial nerve passed by contacting the medial border of the lateral semicircular canal dome, it was classified as type 2; and if the facial nerve contacted the lateral border of the lateral semicircular canal dome or passed more laterally, it was classified as type 3.Results: In total, 309 ears of 257 patients [139 males (54.1%) and 118 females (45.9%)] were included in the study. Ninety-three (30.1%) of the ears were classified as type 1, 179 (57.9%) were type 2, and 37 (12%) were type 3. It was found that the combined posterior tympanotomy/endomeatal approach was used in 6 ears (1.9%), of which 4 were type 3, and 2 were type 2 (P = .006).Conclusion: Systematic evaluation of the relationship between facial nerve and lateral semicircular canal in computed tomography axial sections might help prevent facial nerve damage that can occur during posterior tympanotomy. It was concluded that type 3 ears should be evaluated in this respect, as a combined posterior tympanotomy/endomeatal approach may be required.