The foramen of Huschke: age and gender specific features after childhood

The relation between persistent foramen tympanicum and degenerative bone alterations in temporomandibular joint region

OBJECTIVES

The aim of this study was to evaluate, using cone-beam computed tomography (CBCT), the relationship of persistent foramen tympanicum (PFT) with degenerative changes in the temporomandibular joint (TMJ) and the presence of pneumatized glenoid fossae and articular eminences.

METHOD

Two experienced oral and maxillofacial radiologists evaluated 510 CBCT scans, from which 94 patients were divided into two groups: G1-patients with PFT and G2-control group. The location of the PFT, presence, or absence of degenerative TMJ changes and morphology were evaluated. Similarly, all images were evaluated for the presence of pneumatized articular eminence and glenoid fossa. The Chi-square test and Fisher's Exact test were used for the categorical variables. A multinomial logistic regression model was performed for subgroup analysis. To assess the estimation-chance occurrence of TMJ alterations the Odds Ratio analysis was used.

RESULTS

Statistically significant results were found for erosion, planning, and subchondral cyst. Regarding TMJ morphology, significant results were found for: round, flat, and others. Moreover, it was possible to observe that patients who had the PFT were approximately 48 times more likely to manifest TMJ alterations and approximately 3 times more likely to manifest articular eminence pneumatization.

CONCLUSION

Since individuals who have FTP have a greater chance of having TMJ and PEA changes, it is important for the dental radiologist to be aware of these signs in CBCT scans for a correct diagnosis.

TRIAL REGISTRATION NUMBER

CAAE: 34328214.3.0000.0104 (11/30/2014).

Otoscopy and imaging features of spontaneous temporomandibular joint herniation into the external auditory canal

Objective:

To explore the otoscopy, CT and MRI features of spontaneous temporomandibular joint(TMJ）herniation(STMJH) into the external auditory canal (EAC) through the persistent foramen of Huschke (PFH).

Methods:

15 cases diagnosed STMJH were collected. The otoscopy, CT data of 15 cases and MRI data of 6 cases were retrospectively reviewed.

Results:

Otoscopy revealed a mass located in the anterior wall of the bony EAC that moved forwards and backwards during mouth opening and closing, respectively. CT showed a soft mass with bony defect in the anterior wall of the EAC, with no enhancement; the bony defect margin was well defined in all cases. The bone adjacent to the PFH was pressed and partially wrapped around the soft mass, as if “holding a ball,” in seven cases. Pseudobone shell around the soft mass was observed in eight cases. Six cases included MRI scans, which showed TMJ soft tissue herniated into the EAC.

Conclusion:

STMJHs have unique otoscopic, CT and MRI features. The examination strategy recommended is dynamic otoscopy and conventional CT, MRI can be chosen when the herniation is complicated by infection or otitis externa or when the patient has TMJ dysfunction; conservative management and follow-up observations are the main treatment strategy recommended.

Advances in knowledge:

Mechanical stress of TMJ on the EAC is thought to cause herniation and the special CT features, the location and size of the PFH, especially the location, are the major risk factors for TMJ herniation in patients with FH.

Prevalence of foramen Huschke: evaluation of the association between mastoid pneumatization volume and the existence of foramen Huschke using cone beam computed tomography

PURPOSE

The study examined the association between mastoid pneumatization (MP) volume and the existence of foramen Huschke (FH).

METHODS

Cone beam computed tomography (CBCT) images of 1117 patients (2234 mastoid regions) were analyzed. The prevalence of FH was calculated. The association of MP volume calculated in 83 patients (48 women, 35 men) with sex, side, and the existence of FH analyzed. T test and Pearson's Chi-square test were used for statistical analyses.

RESULTS

FH was observed in 223 (20%) patients. FH was unilateral in 141 (63.7%) patients (74 left-sided, 68 right-sided) and bilateral in 81 (36.3%) patients. Six patients with FH had herniation into the external auditory canal. MP volume was significantly greater in females (p = 0.016). Additionally, MP volume was significantly greater in patients having FH (p = 0.009).

CONCLUSION

It is possible to speculate that the volume of MP, which is in close neighborhood with the external auditory canal, somehow affects the existence of FH located in the tympanic segment.

Cone-beam computed tomographic study of the persistent foramen tympanicum according to age, sex, and skeletal patterns

This cross-sectional study evaluated the influence of prevalence, laterality and diameter of persistent foramen tympanicum (PFT) in cone beam computed tomographic (CBCT) scans of adult patients with different sagittal skeletal patterns, sex and age. CBCT of 510 patients were assessed for the presence of PFT. Skeletal pattern, age and sex of the affected patients were recorded, as well as laterality and diameter of PFT. Differences were tested using the one-way ANOVA, chi squared and paired-t tests, at α=5%. A total of 49 (9.7%) patients presented with PFT; 36 (73.5%) were women (p<0.01) aging from 31-50 years (p>0.05), with Class III skeletal pattern (p>0.05). The unilateral/bilateral ratio was 3.9:1 (p<0.01). No correlation was found between the PFT diameters with sex and age, but differences were found between the classes, with the largest diameters in Class II individuals (p=0.046). The prevalence of PFT in CBCT scans was 9.7%, with women being more affected, with unilateral defects in most cases. Skeletal patterns did not have significant effects on PFT prevalence, although PFT diameter varied among classes, with higher measures in Class II individuals.

A Persistent Foramen of Huschke: A Small Road to Misery in Necrotizing External Otitis

BACKGROUND AND PURPOSE

Necrotizing external otitis is a serious complication of external otitis with different spreading patterns. A persistent foramen of Huschke is a dehiscence located antero-inferior in the osseous external ear canal and posterior-medial to the temporomandibular joint. This dehiscence can facilitate extension of infection in an anterior pattern next to classic spread along the fissures of Santorini. The aim of this study was to define the prevalence and size of a persistent foramen of Huschke in patients with necrotizing external otitis.

MATERIALS AND METHODS

We retrospectively examined 78 CT temporal bone studies (39 patients with necrotizing external otitis, 39 control subjects). The side and presence of the foramen were noted, and its prevalence was calculated. The maximal width of the foramen of Huschke was measured in the axial plane and classified as subtle, mild, moderate, or extensive.

RESULTS

A persistent foramen of Huschke was present in 21 patients (26 ears) and 7 control subjects (9 ears). Prevalence was 50% (20/40) and 11.5% (9/78) in affected ears of patients with necrotizing external otitis and control subjects, respectively. Almost all affected ears showed an anterior distribution pattern of necrotizing external otitis. The extensive dehiscence was most common in affected ears.

CONCLUSIONS

An anterior necrotizing external otitis spreading pattern is associated with the presence and increased size of a persistent foramen of Huschke. These findings facilitate the theory that a persistent foramen of Huschke is an additional risk factor the development of necrotizing external otitis.

Relationship between the degree of mastoid pneumatization and the presence of persistent foramen of Huschke

The aim of this study was to determine the relationship between the degree of mastoid pneumatization and the presence of persistent foramen of Huschke (FH). Temporal computed tomography images of 714 patients (1428 ears) who applied to the Otorhinolaryngology Department of Karabuk University Training and Research Hospital between January 2016 and June 2018 were retrospectively analysed. We compared the mastoid pnomatization levels of 95 patients (74 females, 21 males, mean age 53.18±15.09years) who had persistent FH and 135 patients (103 females, 32 males, mean age 54.29±15.82years) with no FH who had similar age and gender. FH was found to be unilateral (right: 23, left: 45) in 68 (71.5%) out of 95 patients with FH, and FH was bilateral in 27 (28.4%) patients. The degree of mastoid pnomatization of the patients with FH was significantly higher than the patients without FH (p=0.015). The degree of pneumatization of the mastoid bone may lead to persistent FH by affecting the ossification process of the tympanic segment, which has a close anatomical relationship with it.

Usefulness of Cone-Bean Computed Tomography Exams to Detect Foramen of Huschke in Diverse Age Group

The foramen of Huschke (FH) is present in the early stages of the temporal bone tympanic portion development. The literature shows that FH may persist in adult individuals and several authors acknowledge its clinical importance, reporting being associated with the dissemination of diseases. Some authors believe that FH presents importance in archeology and forensic situations.Considering that the identification of FH by conventional imaging methods is extremely impaired or impossible due to overlapping bone structures and that cone-bean computed tomography presents quality in the evaluation of this structure, the authors conducted this research to determine the FH prevalence and dimensions through the Invivo5 software, and correlated its size with age.The foramen was present in 19 scans (12.7%), 6 (8.8%) were present among male and 13 (15.8%) among female. The χ test was performed, with no statistically significant difference for gender and age. Considering the age, in individuals aged 7 to 18 years, 16.4% of persistent FH was found compared with 10.5% in individuals over 18 years of age. The diameter ranged from 2.58 to 3.28 mm. No correlation was found between size and age (p between 0.25 and 0.88).The authors conclude that the cone-bean computed tomography is an examination that allows the correct evaluation of the FH and, although the persistence of this unusual anatomical variation presents different frequencies in the different populations and age groups, it can have clinical consequences, so that the professionals who work in the area must be aware of its existence.

Incidence of Foramen Tympanicum (of Huschke): Comparing Cadaveric and Radiologic Studies

PURPOSE

The foramen tympanicum (FT) represents a developmental anomaly that forms due to incomplete fusion of processes of the tympanic ring. Its presence in the population is controversial and it has been associated with a number of otologic complications. The aim of this study was to systematically analyze the prevalence, anatomical characteristics, and ethnic variations of the FT and compare these parameters in cadaveric and radiologic studies.

METHODS

An extensive search was conducted through the major electronic databases, and identified articles were separated into 2 groups based on their methodology: cadaveric and radiologic studies. Data extracted included study modality, prevalence data, ethnicity, gender, side, laterality, and diameter.

RESULTS

A total of 8 studies (n = 2671 patients) were included into our meta-analysis. The main findings revealed that the prevalence of the FT in the population is 14.9%, it is more often unilateral (62.5%) than bilateral (37.5%), it is most often reported in Asia (21.4%), and it is more prevalent in cadavers (21.2%) than in radiologic studies (8.8%) (not statistically significant).

CONCLUSION

As the FT is present in more than one-tenth of the population, it is important to consider the possibilities of its presence when undertaking surgical procedures in the temporomandibular joint and ear region and plan accordingly to avoid injuries. Clinicians should keep it as one of the possible diagnoses while confronted with patients presenting with otologic complications. The use of newer imaging techniques was recommended, such as cone-beam computer tomography to detect the FT prior to surgery.

Foramen tympanicum with symptomatic temporomandibular joint herniation

Foramen tympanicum (FT), or foramen of Huschke, describes an uncommon anatomicvariant of a persistent bony defect connecting the external acoustic meatus to the temporomandibular joint (TMJ). Although rare, it can be associated with significant complications, such as TMJ herniation, salivary gland fistula, infectious or tumoral spread between the external acoustic meatus and the TMJ, or result in inadvertent ear injury during TMJ arthroscopy. To the best of our knowledge, this is the first case report of a symptomatic FT with a full description of computed tomography and magnetic resonance imaging findings. Surgical exploration confirmed the presence of FT with TMJ herniation with subsequent successful closure of the defect obtained.

Transient Hearing Loss and Objective Tinnitus Induced by Mouth Opening: A Rare Connection Between the Temporomandibular Joint and Middle Ear Space

OBJECTIVES

To describe objective tinnitus complicated with transient low-tone hearing loss coinciding with mouth opening, which was related to the connection between the mandibular fossa and middle ear space.

PATIENTS

A 41-year-old man presented with tinnitus, ear fullness, and hearing loss in the left ear on mouth opening.

MAIN OUTCOME MEASURES

Clinical case records, audiological data, and radiological analyses including computed tomography (CT) and magnetic resonance imaging.

RESULTS

Hearing thresholds on the affected side, which were evaluated with mouth opening, showed elevations of approximately 20 dB in the frequencies below 1000 Hz. Again, peak pressure on the tympanogram deviated negatively to -220 mmH2O under mouth opening without changing peak amplitude. CT showed a connection between the mandibular fossa and middle ear space, as revealed by a gas collection around the joint capsule evaluated in two phases (with and without mouth closing). Ear symptoms resolved after myringotomy.

CONCLUSIONS

Although an influence of temporomandibular disorder (TMD) on tinnitus perception has been debated, whether this association is causal or fortuitous has remained contentious. The present case showed a unique feature of tinnitus attributed to a connection between the mandibular fossa and middle ear space.

Endoscopic Anatomy of the Pediatric Middle Ear

Traditionally, otologists have aimed to produce a clean, dry, safe ear with the best possible hearing result. More recently, “less invasively” has been added to this list of goals. The development of small-diameter, high-quality rigid endoscopes and high-definition video systems has made totally endoscopic, transcanal surgery a reality in adult otology and a possibility in pediatric otology. This article reviews the anatomy of the pediatric middle ear and its surrounding airspaces and structures based on the work of dozens of researchers over the past 50 years. It will focus on the developmental changes in ear anatomy from birth through the first decade, when structure and function change most rapidly. Understanding the limits and possibilities afforded by new endoscopic technologies, the pediatric otologist can strive for results matching or exceeding those achieved by more invasive surgical approaches.