The Role of Computed Tomography in the Diagnosis of Congenital Sensorineural Hearing Loss.

Introduction One of the paths in the investigation of congenital sensorineural hearing loss (CSNHL) is to try to characterize its etiology through the inner ear evaluation using high resolution computer tomography (CT) scans. With minor malformation, it is not always possible for a simple visual inspection to recognize if the structure in the inner ear is normal or not. Objective To verify if measurements of the inner ear are predictive of sensorineural hearing loss (SNHL) and suggest cutoff points of size limits. Methods Retrospective cross-sectional study of inner ear CT scan measurements of 214 patients, 50 with congenital SNHL (CSNHL) and 164 acquired SNHL (ASNHL) (control group). Results In the CSNHL group, central bony island (CBI) were 0.48 mm smaller ( p < 0.001), cochlear nerve aperture was (CNA) 0.10 mm smaller ( p < 0.001), and cochlea height was (CH) 0.15 mm smaller ( p < 0.001). Vestibular aqueduct (VA) and cochlea width (CW) were similar between groups (0.70 vs 0.72, p = 0.19, and 7.20 vs 7.15 p = 0.23). The predictive cutoff points for CSNHL were CBI = 3.6 mm, CAN = 1.4 mm, CH = 3.4 mm, CW = 7.0 mm, and VA = 0.9 mm. Conclusion Congenital sensorineural hearing loss determined a decrease in CBI, opening of the cochlear nerve (OCN), and CW. Thus, these measures, at the cutoff points indicated, should make us aware of the diagnosis of congenital hearing loss.

A Clinicopathological Study of Aural Polyps: A Retrospective Analysis in a Tertiary Care Hospital.

Introduction Aural polyps are a misnomer. Any lesion can present as a mass in the external auditory canal. Aural polyps are proliferation of the granulation tissue due to long standing inflammatory process with associated otalgia and otorrhea. Objectives To document the clinicoradiological presentations, intraoperative findings, and histopathological diagnosis of aural polyp, correlating them. Methods In our study 81 patients underwent treatment for aural polyps in the department of Ear, Nose, and Throat (ENT) from April 1997 to April 2022. Results were tabulated, a simple descriptive analysis was done using the Statistical Package Social Sciences software, and the results obtained were represented as percentages and presented in tables. Results The majority (38) of the patients presenting with aural polyps were diagnosed with mucosal and squamous type of CSOM, and 22 with simple granulation polyps. There were also 5 patients with malignant otitis externa, 3 patients had glomus tumors, 2 patients with retained foreign bodies, and 3 patients with brain herniation. We also identified aberrant internal carotid artery, high jugular bulb, one patient had facial nerve neuroma, one patient had polyp from the tragus diagnosed with tuberculosis, one patient with keratosis obturans, and one with exostosis. Conclusion A thorough detailed examination and mastoid exploration with radiological and histopathological evaluation is mandatory for better defining the definitive treatment. Utmost care and meticulousness are advised for the surgeons while dealing with aural polyps to avoid any complications.

Three-dimensional replica of the temporal bone in the teaching of human anatomy.

PURPOSE: The current study proposes the comparison of the visualization and identification of anatomical details between natural human temporal bone, its respective copy from three-dimensional printing, and the virtual model obtained from CBCT. METHODS: The sample consisted of undergraduate students in Dentistry (Group UE, n = 22), Postgraduate students in Radiology and Imaging (Group P-RI, n = 20), and Postgraduate students in Forensic Odontology (Group P-FO, n = 24). All participants attended a theoretical class on specialized anatomy of the temporal bone and subsequently performed the markings of 10 determined structures. RESULTS: The number of correct identifications was similar in natural bone and printed three-dimensional models in all groups (p > 0.05). The virtual model showed a significantly lower number of correct structures (p < 0.05) in the 3 groups. In general, there were significantly higher percentages of accurate answers among postgraduate students compared to undergraduate students. Most graduate students believed that the printed three-dimensional model could be used to teach anatomy in place of natural bone, while undergraduate students disagreed or were unsure (p < 0.05). Regarding the virtual tomographic image, in all groups, students disagreed or were not sure that its use would be beneficial in replacing natural bone. CONCLUSION: Three-dimensional and virtual models can be used as auxiliary tools in teaching anatomy, complementing practical learning with natural bones.

The endoscopic transcanal approach to the internal auditory canal: an anatomic study.

PURPOSE: The internal auditory canal (IAC) plays a key role in lateral skull base surgery. Although several approaches to the IAC have been proposed, endoscope-assisted transcanal corridors to the IAC have rarely been studied. We sought to provide a step-by-step description of the transcanal transpromontorial approach to the IAC and analyze anatomic relationships that might enhance predictability and safety of this approach. METHODS: Ten cadaveric specimens were dissected and the extended transcanal transpromontorial approach to the IAC was established. Various morphometric measurements and anatomic landmarks were reviewed and analyzed. RESULTS: The proposed technique proved feasible and safe in all specimens. There was no inadvertent injury to the jugular bulb or internal carotid artery. The chorda tympani, a key landmark for the mastoid segment of the facial nerve, was identified in all dissections. The spherical recess of the vestibule and middle turn of cochlea are important landmarks for identification of the labyrinthine segment of the facial nerve. Identification of all boundaries of the working area is also essential for safe access. Among various morphometric measurements, the modiolus-IAC angle (≈ 150°) proved particularly consistent; given its ease of use and low variability, we believe it could serve as a landmark for identification and subsequent dissection of the IAC. CONCLUSIONS: The extended transcanal transpromontorial approach to the IAC is feasible and safe. Relying on anatomic landmarks to ensure preservation of the involved neurovascular structures is essential for a successful approach. The modiolus-IAC angle is a consistent, reproducible landmark for IAC identification and dissection.

Temporal bone squamous cell carcinoma: Aggressive behavior coursing with cerebellar invasion and hydrocephalus.

Background: Temporal bone squamous cell carcinoma (TBSCC) is a very rare condition. The prognosis is dismal for advanced tumors. Due to its rarity, information in the literature is scarce. Here, we report a unique case of TBSCC with cerebellar invasion and hydrocephalus. Case Description: A 46-year-old reported right-sided hearing loss and a painful right retroauricular mass for 4 months. Magnetic resonance imaging revealed a 8.7 × 7.6 × 6.4 cm mass invading the right temporal and occipital bones. After a biopsy and 3 surgical procedures over 6 months, the diagnosis of TBSCC was obtained. Due to invasion of the cerebellar tissue and obstructive hydrocephalus, a ventriculoperitoneal shunt was performed. The patient was referred for adjuvant radiotherapy. However, palliative care was initiated due to tumor progression. Conclusion: We report a case of advanced TBSCC with poor prognosis despite surgical treatment and radiotherapy. More data are necessary to provide new and better treatment to these patients.

The variations of osseous structure of the internal acoustic canal: an anatomical study.

OBJECTIVES: The internal acoustic meatus is an osseous canal that connects the inner ear to the posterior cranial fossa. It is located in the petrous portion of the temporal bone. A thin cribriform osseous plate known as the fundus is situated at the lateral end of the canal. This study assesses the structural and numerical variations of the fundus formations. METHODS: Fifty-four temporal bones of unknown gender and age were examined with the surgical microscope. RESULTS: The temporal bones analyzed were 46.2% right-sided and 53.7% left-sided. Only one temporal bone had two parallel transverse crests, while three had a single anterior crest that split into two branches posteriorly. The number of foramina at the transverse crest varied, with 29.6% having none, 48.1% having a single foramen, and 22.2% having several foramina. An anterior crest structure was seen in 53.7% of the temporal bones, with 5% having a slightly constricted entry to the facial canal. In cases with a single nerve foramen, 48.1% had one, while 51.8% had more than one, including examples with three or four foramina. A crest was found between the foramina of the single nerve in 7% of patients. Furthermore, a crest between the saccular nerve foramen and the high fiber foramina was seen in 25.9% of cases, and 5% had two saccular nerve foramina. CONCLUSION: We think that revealing the anatomical, structural and numerical variations in the fundus will be useful in explaining the disease-symptom relationship. LEVEL OF EVIDENCE: Level 4.

Thermal variation in human temporal bone using rigid endoscope.

OBJECTIVE: Compare thermal variation in the region of the External Acoustic Canal (EAC) and the Round Window (RW) using different rigid endoscopes and light sources in human temporal bones. METHOD: This is an analytical experimental study using human temporal bones. Thermal variation was assessed during ten minutes, using a thermometer in the region of the EAC and the RW of two temporal bones, right and left. We used three different endoscopes (0° 4-mm, 0° 3-mm and 30° 4-mm) and five intensity/type light source (Halogen 100%, LED 50%, LED 100%, Xenon 50% and Xenon 100% with the same endoscope light fiber. RESULTS: We found temperature elevations in the EAC and RW in all measurements. Larger caliber endoscopes (4-mm) and light sources at 100% intensity generated higher temperatures, slightly higher in halogen and xenon. The 30° endoscopes tended to put more heat on structures, with little difference in most measurements. We identified greater temperature variations in the EAC of the right and left temporal bones compared to the RW overall. The highest temperature acquired in the present study was in the EAC of the temporal bone with a 4-mm and 30° endoscope, using xenon light source (intensity of 100%), with an increase of 4.51 °C. CONCLUSION: The type of endoscope and light source can influence the thermal variation and the risk of tissue injury during endoscopic ear surgery. Larger endoscopes with xenon and halogen light sources at maximum intensity generate more heat.

Detailed analysis of inner ear malformations in CHARGE syndrome patients - correlation with audiological results and proposal for computed tomography scans evaluation methodology.

OBJECTIVES: The aim was to describe the spectrum of inner ear malformations in CHARGE syndrome and propose a Computed Tomography (CT) detailed scan evaluation methodology. The secondary aim was to correlate the CT findings with hearing thresholds. METHODS: Twenty ears of ten patients diagnosed with CHARGE syndrome were subjected to CT analysis focusing on the inner ear and internal acoustic canal. The protocol used is presented in detail. ASSR results were analyzed and correlated with inner ear malformations. RESULTS: Cochlear hypoplasia type III was the most common malformation found in 12 ears (60%). Cochlear hypoplasia type II, aplasia with a dilated vestibule, and rudimentary otocyst were also identified. In 20%, no cochlear anomaly was found. The lateral Semicircular Canal (SCC) absence affected 100% of ears, the absence of the posterior SCC 95%, and the superior SCC 65%. Better development of cochlea structures and IAC correlated significantly with the lower hearing thresholds. CONCLUSION: This study demonstrated that rudimentary SCC or a complete absence of these SCCs was universally observed in all patients diagnosed with CHARGE syndrome. This finding supports the idea that inner ear anomalies are a hallmark feature of the CHARGE, contributing to its distinct clinical profile. The presence of inner ear malformations has substantial clinical implications. Audiological assessments are crucial for CHARGE syndrome, as hearing loss is common. Early detection of these malformations can guide appropriate interventions, such as hearing aids or cochlear implants, which may significantly improve developmental outcomes and communication for affected individuals. Recognizing inner ear malformations as a diagnostic criterion presents implications beyond clinical diagnosis. A better understanding of these malformations can advance the knowledge of CHARGE pathophysiology. It may also help guide future research into targeted therapies to mitigate the impact of inner ear anomalies on hearing and balance function.

Detailed analysis of inner ear malformations in CHARGE syndrome patients - correlation with audiological results and proposal for computed tomography scans evaluation methodology

Abstract Objectives The aim was to describe the spectrum of inner ear malformations in CHARGE syndrome and propose a Computed Tomography (CT) detailed scan evaluation methodology. The secondary aim was to correlate the CT findings with hearing thresholds. Methods Twenty ears of ten patients diagnosed with CHARGE syndrome were subjected to CT analysis focusing on the inner ear and internal acoustic canal. The protocol used is presented in detail. ASSR results were analyzed and correlated with inner ear malformations. Results Cochlear hypoplasia type III was the most common malformation found in 12 ears (60%). Cochlear hypoplasia type II, aplasia with a dilated vestibule, and rudimentary otocyst were also identified. In 20%, no cochlear anomaly was found. The lateral Semicircular Canal (SCC) absence affected 100% of ears, the absence of the posterior SCC 95%, and the superior SCC 65%. Better development of cochlea structures and IAC correlated significantly with the lower hearing thresholds. Conclusion This study demonstrated that rudimentary SCC or a complete absence of these SCCs was universally observed in all patients diagnosed with CHARGE syndrome. This finding supports the idea that inner ear anomalies are a hallmark feature of the CHARGE, contributing to its distinct clinical profile. The presence of inner ear malformations has substantial clinical implications. Audiological assessments are crucial for CHARGE syndrome, as hearing loss is common. Early detection of these malformations can guide appropriate interventions, such as hearing aids or cochlear implants, which may significantly improve developmental outcomes and communication for affected individuals. Recognizing inner ear malformations as a diagnostic criterion presents implications beyond clinical diagnosis. A better understanding of these malformations can advance the knowledge of CHARGE pathophysiology. It may also help guide future research into targeted therapies to mitigate the impact of inner ear anomalies on hearing and balance function. Level of evidence: 4.

Thermal variation in human temporal bone using rigid endoscope

Abstract Objective Compare thermal variation in the region of the External Acoustic Canal (EAC) and the Round Window (RW) using different rigid endoscopes and light sources in human temporal bones. Method This is an analytical experimental study using human temporal bones. Thermal variation was assessed during ten minutes, using a thermometer in the region of the EAC and the RW of two temporal bones, right and left. We used three different endoscopes (0° 4-mm, 0° 3-mm and 30° 4-mm) and five intensity/type light source (Halogen 100%, LED 50%, LED 100%, Xenon 50% and Xenon 100% with the same endoscope light fiber. Results We found temperature elevations in the EAC and RW in all measurements. Larger caliber endoscopes (4-mm) and light sources at 100% intensity generated higher temperatures, slightly higher in halogen and xenon. The 30° endoscopes tended to put more heat on structures, with little difference in most measurements. We identified greater temperature variations in the EAC of the right and left temporal bones compared to the RW overall. The highest temperature acquired in the present study was in the EAC of the temporal bone with a 4-mm and 30° endoscope, using xenon light source (intensity of 100%), with an increase of 4.51 °C. Conclusion The type of endoscope and light source can influence the thermal variation and the risk of tissue injury during endoscopic ear surgery. Larger endoscopes with xenon and halogen light sources at maximum intensity generate more heat. Level of evidence: 5.

The variations of osseous structure of the ınternal acoustic canal: an anatomical study

Abstract Objectives The internal acoustic meatus is an osseous canal that connects the inner ear to the posterior cranial fossa. It is located in the petrous portion of the temporal bone. A thin cribriform osseous plate known as the fundus is situated at the lateral end of the canal. This study assesses the structural and numerical variations of the fundus formations. Methods Fifty-four temporal bones of unknown gender and age were examined with the surgical microscope. Results The temporal bones analyzed were 46.2% right-sided and 53.7% left-sided. Only one temporal bone had two parallel transverse crests, while three had a single anterior crest that split into two branches posteriorly. The number of foramina at the transverse crest varied, with 29.6% having none, 48.1% having a single foramen, and 22.2% having several foramina. An anterior crest structure was seen in 53.7% of the temporal bones, with 5% having a slightly constricted entry to the facial canal. In cases with a single nerve foramen, 48.1% had one, while 51.8% had more than one, including examples with three or four foramina. A crest was found between the foramina of the single nerve in 7% of patients. Furthermore, a crest between the saccular nerve foramen and the high fiber foramina was seen in 25.9% of cases, and 5% had two saccular nerve foramina. Conclusion We think that revealing the anatomical, structural and numerical variations in the fundus will be useful in explaining the disease-symptom relationship. Level of evidence: Level 4.

Tinnitus Footprints in the Cochlea.

The purpose of this paper is to show how temporal bone histopathology has been instrumental in adding knowledge about the origin of tinnitus in the cochlea and how it will still be useful for that purpose in the future. The papers published on this subject will be reviewed, and their contributions will be highlighted. The knowledge that is now part of the subject will be pointed out, and future research on this area will be pointed out.

Evaluation of the Radiological Anatomy of the Temporal Bone Air Spaces and Morphometric Analysis in Turkish Healthy Adults / Evaluación de la Anatomía Radiológica de los Espacios Aéreos del Hueso Temporal y Análisis Morfométrico en Adultos Turcos Sanos

SUMMARY: The temporal bone is a complicate structure which located on the lateral skull. The objective of the present study was to determine the temporal bone air spaces' morphometry, morphology, and pneumatization in Turkish healthy adult people. This retrospective observational study was carried out from 82 subjects (47 males, 35 females) aged 18-69 years. The external auditory canal and related structures' diameters and the volume of these areas were evaluated. The means and standard deviations of the Meatus acusticus externus length (MAEL), meatus acusticus externus pars cartilaginea length (MAEcL), meatus acusticus externus pars ossea length (MAEoL), meatus acusticus externus pars cartilaginea surface (MAEcS), meatus acusticus externus pars ossea surface (MAEoS), meatus acusticus externus volume (MAEV), meatus acusticus externus pars cartilaginea volume (MAEcV), meatus acusticus externus pars ossea volume (MAEoV), processus mastoideus air cells volume (PMACV), cavum tympani volume (CTV), and temporale pneumatic spaces volume (OTPSV) were found as 23.21±3.70 mm, 12.69±3.72 mm, 7.80±3.70 mm, 669.89±107.7 mm2, 267.50±30.51 mm2, 743.50±119.6 mm3, 971.97±156.69 mm3, 419.51±48.67 mm3, 5915.93±650.34 mm3, 673.48±91.93 mm3, 7813.34±717.49 mm3 have found in 82 subjects, respectively. In this paper, the morphometric and volume properties of the temporal bone cavities measurements were significantly higher in males than females. These results may both provide reference values of Turkish healthy population, and lead to decrease potential surgical complications about temporal and mastoid regions.

El hueso temporal es una compleja estructura ubicada en el parte lateral del cráneo. El objetivo del presente estudio fue determinar la morfometría, morfología y neumatización de los espacios aéreos del hueso temporal en individuos adultos turcos sanos. Este estudio observacional retrospectivo que se llevó a cabo en 82 sujetos (47 hombres, 35 mujeres) de entre 18 y 69 años. Se evaluaron los diámetros del meato acústico externo y las estructuras relacionadas y el volumen de estas áreas. Las medias y las desviaciones estándar de la longitud del meato acústico externo (MAEL), la longitud de la parte cartilaginosa del meato acústico externo (MAEcL), la longitud de la parte ósea del meato acústico externo (MAEoL), la superficie de la parte cartilaginosa del meato acústico externo (MAEcS), la superficie de la parte ósea del meato acústico externo (MAEoS), volumen del meato acústico externo (MAEV), volumen de la parte cartilaginosa del meato acústico externo (MAEcV), volumen de la parte ósea del meato acústico externo (MAEoV), volumen de las células aéreas del proceso mastoideo (PMACV), volumen del cavum tympani (CTV) y el volumen de los espacios neumáticos temporales (OTPSV) se encontró como 23,21 ± 3,70 mm, 12,69 ± 3,72 mm, 7,80 ± 3,70 mm, 669,89 ± 107,7 mm2, 267,50 ± 30,51 mm2, 743,50 ± 119,6 mm3, 971,97 ± 156,69 mm3, 419,5. 1±48,67 mm3, 5915,93 ± 650,34 mm3, 673,48 ± 91,93 mm3, 7813,34 ± 717,49 mm3, respectivamente. En este artículo, las propiedades morfométricas y de volumen de las mediciones de las cavidades del hueso temporal fueron significativamente mayores en hombres que en mujeres. Estos resultados pueden proporcionar valores de referencia de la población sana turca y conducir a una disminución de las posibles complicaciones quirúrgicas en las regiones temporal y mastoidea.

Prevalence, morphology, morphometry and associated clinical implications of mastoid emissary veins: narrative review.

The mastoid emissary vein connects the posterior auricular vein to the sigmoid sinus and varies in size, number, location, and course, resulting in clinical complications. This study was conducted in response to the vast clinical implications associated with this vein. The aim of this review is to highlight and describe the prevalence, varied morphology, and morphometry of the mastoid emissary vein, how these varied parameters cause clinical complications, and how these can be rectified and avoided. A literature survey was conducted using various databases and different terms related to mastoid emissary vein were used to search the literature. Pitfalls related to surgery in the vicinity of this vein and their remedies were elucidated. The literature search revealed that the prevalence, morphology, and morphometry of mastoid emissary veins vary immensely and are responsible for morbidity and mortality. Pre-operative identification of mastoid veins is thus essential and so multidetector computed tomography of the temporal bone should be scheduled before planning surgery.

A veia emissária mastóidea que conecta a veia auricular posterior ao seio sigmoide pode variar em tamanho, número, localização e curso, resultando em complicações clínicas. O objetivo desta revisão é destacar e descrever a prevalência, variação morfológica e morfometria da veia emissária mastóidea, além de como esses parâmetros causam complicações clínicas e como corrigi-las e reduzi-las. Foram conduzidas buscas em diversas bases de dados utilizando diferentes termos relacionados à veia emissária mastóidea. As armadilhas relacionadas a procedimentos cirúrgicos realizados nas proximidades dessa veia e as respectivas soluções foram descritas. A pesquisa na literatura revelou que a prevalência, a morfologia e a morfometria da veia emissária mastóidea variam imensamente, sendo responsáveis ​​por alta morbidade e mortalidade. Portanto, a identificação da veia mastóidea deve ser realizada no pré-operatório através de tomografia computadorizada multidetectores do osso temporal, antes do planejamento cirúrgico.

"Leave me alone": anatomical structures and variations seen on computed tomography of the temporal bone.

The anatomical structure of the temporal bone is quite complex. There are a great number of anatomical variations that are often confused with temporal bone pathologies, especially fractures. It is important that radiologists and surgeons be able to recognize such variations.

O osso temporal é uma estrutura anatômica óssea bastante complexa. Apresenta grande número de variações anatômicas, que muitas vezes são confundidas com lesões ou doenças, principalmente fraturas. O reconhecimento dessas variações é importante para radiologistas e cirurgiões.

Biomateriales y tecnologías de impresión 3D en entrenamiento quirúrgico en otorrinolaringología: una revisión / Biomaterials and technologies of 3D printing in surgical training on otorhinolaryngology: a revision

La tecnología de fabricación aditiva o impresión 3D se ha posicionado como una herramienta transversal y de uso creciente en el mundo productivo y científico que ha otorgado la posibilidad de diseñar y crear elementos y modelos de diversa complejidad. En el área biomédica ha presentado un aumento significativo de sus aplicaciones a través del tiempo, actualmente teniendo relevancia en ámbitos como el planeamiento quirúrgico, la creación de prótesis, modelos anatómicos para educación y entrenamiento quirúrgico. Actualmente existen diversas dificultades que limitan la formación quirúrgica, especialmente en ciertas áreas de la otorrinolaringología como la cirugía de oído. El objetivo de la presente revisión narrativa fue actualizar los usos de la tecnología de impresión 3D para la creación de modelos para entrenamiento quirúrgico en otorrinolaringología, destacando sus potenciales usos en otología, rinología, cirugía de base de cráneo y vía aérea.

Additive manufacturing technology or 3D printing has positioned itself as a cross-cutting tool of increasing use in the productive and scientific world that has given the possibility of designing and creating different elements and models of varying complexity. In the biomedical area, it has presented a significant increase in its applications over time, currently having relevance in areas such as surgical planning, the creation of prostheses, anatomical models for education and surgical training. Currently there are various difficulties that limit surgical training, especially in certain areas of otorhinolaryngology such as ear surgery. The objective of this narrative review was to update the uses of 3D printing technology for the creation of models for surgical training in otorhinolaryngology, highlighting its potential uses in otology, rhinology, skull base and airway surgery.

"Leave me alone": anatomical structures and variations seen on computed tomography of the temporal bone / "Deixe-me em paz": estruturas e variações anatômicas observadas em tomografia computadorizada do osso temporal

Abstract The anatomical structure of the temporal bone is quite complex. There are a great number of anatomical variations that are often confused with temporal bone pathologies, especially fractures. It is important that radiologists and surgeons be able to recognize such variations.

Resumo O osso temporal é uma estrutura anatômica óssea bastante complexa. Apresenta grande número de variações anatômicas, que muitas vezes são confundidas com lesões ou doenças, principalmente fraturas. O reconhecimento dessas variações é importante para radiologistas e cirurgiões.

Anatomy of the mastoid triangle and morphometric sex differences.

OBJECTIVE OF THE STUDY: This study aimed to quantify the area of the mastoid triangle (MT) and assess potential morphometric differences between males and females. PATIENTS: The sample consisted of 244 dry human skulls, with biological sex known based on genetic analysis, collected from a medicolegal osteological database from Central-Western Brazil. MATERIALS AND METHODS: The study was observational, analytical, and cross-sectional. The skulls were analyzed using Heron's equation to calculate the area of the MT. The landmarks connecting each of the sides of the triangle were: Porion (Po)>Mastoidale (Ma)>Asterion (Ast). Morphometric references were calculated and compared based on sex. RESULTS: The area of the MT was nearly 14% larger in males compared to females (p<0.05). The mean MT area for the right and left sides of males were 684.11±93.25mm2 and 668.94±111.95mm2, respectively. In females, the mean MT for the right and left sides were 588.93±91.09mm2 and 582.88±102.98mm2, respectively. Right and left side measurements were significantly different (p<0.05), except for Po-Ast (p=0.232). CONCLUSION: Morphometric features regarding the MT were slightly different between males and females. Application of the MT as a dimorphic tool should be adjuvant. Moreover, this tool should be considered carefully, especially because the sex-based differences were statistically significant, but discrete between males and females.

Prevalence, morphology, morphometry and associated clinical implications of mastoid emissary veins: narrative review / Prevalência, morfologia, morfometria e implicações clínicas das veias emissárias mastóideas: uma revisão narrativa

Abstract The mastoid emissary vein connects the posterior auricular vein to the sigmoid sinus and varies in size, number, location, and course, resulting in clinical complications. This study was conducted in response to the vast clinical implications associated with this vein. The aim of this review is to highlight and describe the prevalence, varied morphology, and morphometry of the mastoid emissary vein, how these varied parameters cause clinical complications, and how these can be rectified and avoided. A literature survey was conducted using various databases and different terms related to mastoid emissary vein were used to search the literature. Pitfalls related to surgery in the vicinity of this vein and their remedies were elucidated. The literature search revealed that the prevalence, morphology, and morphometry of mastoid emissary veins vary immensely and are responsible for morbidity and mortality. Pre-operative identification of mastoid veins is thus essential and so multidetector computed tomography of the temporal bone should be scheduled before planning surgery.

Resumo A veia emissária mastóidea que conecta a veia auricular posterior ao seio sigmoide pode variar em tamanho, número, localização e curso, resultando em complicações clínicas. O objetivo desta revisão é destacar e descrever a prevalência, variação morfológica e morfometria da veia emissária mastóidea, além de como esses parâmetros causam complicações clínicas e como corrigi-las e reduzi-las. Foram conduzidas buscas em diversas bases de dados utilizando diferentes termos relacionados à veia emissária mastóidea. As armadilhas relacionadas a procedimentos cirúrgicos realizados nas proximidades dessa veia e as respectivas soluções foram descritas. A pesquisa na literatura revelou que a prevalência, a morfologia e a morfometria da veia emissária mastóidea variam imensamente, sendo responsáveis ​​por alta morbidade e mortalidade. Portanto, a identificação da veia mastóidea deve ser realizada no pré-operatório através de tomografia computadorizada multidetectores do osso temporal, antes do planejamento cirúrgico.

The Endoscopic Anatomy of the External Acoustic Meatus and of the Middle Ear in Dry Temporal Bones: A Study Conducted Using Digital and Mobile Device Technology

Abstract Introduction The endoscopic anatomy of the middle ear (ME) and of the external acoustic meatus (EAM) has been described in cadavers, in fresh temporal bones, or in vivo using conventional video recording, but not in dry bones or using an alternative inspection and recording technique. Objective To study the anatomy of the ME and of the EAM in dry temporal bones using a smartphone-endoscope system. Methods The EAM and the ME were studied in dry temporal bones using an endoscopic transcanal approach with a telescope connected to a smartphone (M-scope mobile endoscope app and adaptador, GBEF Telefonia, São Paulo, SP, Brazil). Results Out of 50 specimens, 2 had exostosis of the EAM and 3 contained remains of the tympanic membrane. The anterior wall of the EAM was prominent in 10/48 specimens (20.8%). Ossicles were seen in 13/45 (28.8%), stapes at the oval window were seen in 12/45 (26.6%), and the incus was seen in 1/45 (2.2%) specimens. The facial canal was open and protruding in 15/45 (33.3%) and in 7/45 (15.5%) specimens, respectively. Of the 45 MEs evaluated, type A was predominant for finiculus (93.3%), subiculum (100%), and ponticulus (95.6%). The rest were type B. None was classified as type C. According to its position in relation to the round window, the fustis was classified into type A (68.9%) or B (31.1%). The pyramidal eminence, the bony portion of the Eustachian tube, the semicanal of the tensor tympani muscle, and the cochleariform process were visualized completely or partially in all cases. Conclusion The use of a smartphone-based endoscopic transcanal procedure in dry temporal bones allowed the evaluation of anatomical variations in the EAM and in the ME.