Temporal Bone Pneumatization Research Articles

Pneumatization pattern of the temporal bone with volumetric assessment and its impact on the frequency of cerebrospinal fluid leak in patients undergoing vestibular schwannoma surgery via the retrosigmoid approach.

Vestibular schwannomas are benign tumors that account for 8% of all intracranial tumors. Due to their location in the cerebellopontine angle and internal auditory canal, access to these lesions requires disruption of the temporal bone. The pneumatization of this bone varies between individuals, and literature reports suggest that it may influence the frequency of cerebrospinal fluid leaks. In our study, we assessed whether the pneumatization of the temporal bone differs in individuals with or without cerebrospinal fluid leak. We conducted a retrospective analysis that initially included 143 individuals, of whom 103 were ultimately qualified for the study. We analyzed the clinical data of the patients and the radiological characteristics of the pneumatization of the temporal bone using volumetric methods, additionally relying on classifications of temporal bone pneumatization. Pneumatization of the temporal bone in patients operated on for vestibular schwannoma with cerebrospinal fluid leakage was significantly higher compared to the group without leakage (Right: 11.15 [IQR 8.93-12.83] vs. 13.25 [IQR 10.15-15.53]; p = 0.040; Left: 10.95 [IQR 9.5-12.26] vs. 14.4 [IQR 13.03-15.7]; p = 0.012). Additionally, a higher degree of pneumatization of the petrous apex was significantly more frequent in the group with cerebrospinal fluid leak in both left (p < 0.001) and right (p < 0.001) side. The analyzed data suggest that greater pneumatization of the temporal bone and a higher degree of petrous apex pneumatization in the classification of temporal bone pneumatization may be associated with an increased risk of cerebrospinal fluid leak. To draw causal inferences, prospective studies in this area are necessary.

Analysis of growth pattern of temporal bone pneumatization using 3D reconstructed computed tomography.

Temporal bone pneumatization (TBP) is influenced by age, sex, and race, and it seems to progress rapidly to puberty. However, the extent of TBP in childhood remains unclear. To investigate the progression of TBP in children aged 1-18 years via three-dimensional (3D) reconstruction of high-resolution computed tomography (CT) images. A total of 432 temporal bones of 216 individuals aged 1-18 years with well-pneumatized mastoid antra on both sides were included in this retrospective work. We created 18 age groups, each with six boys and six girls. Surface rendering of air density was performed using -290 HU to obtain TBP. Statistical analysis employed SPSS version 24.0 software (IBM Corp., Armonk, NY, USA). The linear regression equations that considered age and volume for all cases (ya), male (ym) and female (yf) were ya = 384.42x + 1790.40, R2 = 0.425; ym = 431.54x + 1440.9, R2 = 0.501; and yf = 337.26 x + 2140.5, R2 = 0.355. Both male and female individuals showed an increase in the average value of pneumatization until the age of 17, and the values ​​of pneumatization at specific ages for boys and girls showed differences. The mean male and female TBP levels differed significantly at 3, 11, and 18 years of age (P < 0.05). TBP in boys was greater than that of girls at adolescence. It was possible to identify the specific periods of significant variation in the degree of pneumatization of temporal bone.

Status and Depth of Mastoid Antrum and the Pattern of Mastoid Pneumatization in Cases of Large, Subtotal Perforations and Posterosuperior Retraction Pockets (PSRP).

The present study aimed to evaluate the pneumatization status of the mastoid air cells in general with the depth and status of mastoid antrum in particular, in patients of chronic otitis media (COM). This is an observational cross-sectional study in sample size of 60 participants with large, subtotal perforation and posterosuperior retraction pocket (PSRP). Mean age with large central and subtotal perforation combined was 35.78 years, compared to 32.13 years in PSRP. Granulations seen in antrum in 71.6% and cholesteatoma observed in 15%. Mean depth of the mastoid antrum was 17.27 mm. A well pneumatized mastoid in 21.6%, diploic 28.3% and sclerotic in 50% was noted in this study. Chronic otitis media affects temporal bone pneumatization, particularly the mastoid antrum. Our findings indicate that the depth of the mastoid antrum is slightly greater in cholesteatoma cases due to bone erosion. As early intervention enhances postoperative quality of life by preserving or restoring auditory function, understanding the mastoid pneumatization and antrum depth is crucial for managing chronic otitis media effectively.

Changes in paranasal sinus volumes, temporal bone pneumatization, internal acoustic canal and olfactory cleft dimensions over the centuries: a comparison of skulls from different epochs in Anatolia

ObjectivesInvestigating changes in temporal bone pneumatization (TBP) and paranasal sinus volumes (PSV) across different eras may help understanding not only changes in skull anatomy but also pathophysiology of chronic otitis media and sinusitis, respectively, which are common health problems.MethodsEight skulls from the second century AD, 20 skulls were from the 10th–11th centuries AD, 20 skulls from the 16th–19th centuries AD, and 60 contemporary skulls were included in this cross-sectional observational study. Using computerized tomography (CT) scans, the PSV were calculated by multiplying the height, width, and antero-posterior distance of the sinuses. TBP was divided into three types. Internal acoustic canal (IAC) length and width, and olfactory cleft (OC) width were measured.ResultsNo statistically significant differences were found between the paranasal sinus (frontal, maxillary, and sphenoid) volumes between the groups. However, TBP decreased statistically significantly over time on both sides of the skulls (p = 0.001). The contemporary IAC and OC measures were found to be significantly lower on both sides compared to the skulls from the other three eras (p < 0.001 for both).ConclusionsAlthough no significant change was observed in PSV, decreases were evident in TBP, OC width and IAC length and width over time. It appears a fair inference that changes in size of OC and IAC might be another indication of the fact that olfaction and hearing were more vital for survival in old eras. Since we do not know incidence of chronic ear problems in old eras, we cannot speculate outcome of increased TBP in terms of developing chronic ear diseases. On the contrary, increased TBP was likely to play a protective role in traumas in old ears. Additionally, the environmental influences may be crucial role in the development of paranasal sinuses.

The Role of Temporal Bone Pneumatization on Fracture Line and Involved Cranial Structures.

Temporal bone pneumatization (TBP) is speculated to serve as a shock absorber in temporal bone fractures (TBF), directing the fracture line away from vital structures. This study correlates TBP extent with TBF patterns and preservations of vital TB structures. Retrospective cohort study. Tertiary referral medical center. All TBF patients referred to a single tertiary center 2017 to 2023 were evaluated. A pneumatization index score for each of their TBs was derived by counting automated-voxel density in a 0 to 100 scale. Results were correlated to the TBF type and the violated structure(s). The ossification index was compared to previously detailed qualitative classification systems of TBP. One hundred and forty-five patients were enrolled (mean age 43 ± 17 years). Kinematics were motor vehicle accidents (46%), scooter (15%), bicycle (14%), falls (13%), and assaults (8%). The mastoid ossification index we used showed a strong correlation to all qualitative classification systems (sigmoid = 0.829; labyrinthine = 0.849; carotis = 0.863, infralabyrinthine = 0.869, all P < .001). The pneumatization index strongly correlated with capsule-violating TBFs, with a mean of 44 ± 23 for otic capsule-sparing TBF and 61 ± 20 for otic capsule-violating (OCV) TBF (P < .001). The facial nerve was violated in 30 patients. Facial canal (FC) involvement was not correlated to the ossification index: it was 49 ± 23 for FC-sparing and 44 ± 23 for FC-violating (P = .620). TBP serves as a protective mechanism against OCV TBF. The more pneumatized the TB, the less likely the otic capsule will be violated in the event of a TBF with the exception of the carotid and FCs. TBP index is in strong agreement with qualitative TBP classification systems.

Development of Air Cell System Following Canal Wall Up Mastoidectomy for Pediatric Cholesteatoma.

Background: The development of temporal bone pneumatization is related to the postnatal middle ear environment, where the development of air cells is suppressed with otitis media in early childhood. However, whether air cell formation restarts when mastoidectomy is performed during temporal bone pneumatization remains unclear. Herein, we evaluated temporal bone pneumatization after canal wall up (CWU) tympanomastoidectomy for middle ear cholesteatoma in children. Methods: In total, 63 patients, including 29 patients with congenital cholesteatoma (CC) and 34 patients with acquired cholesteatoma (AC), were assessed using a set of pre- and postoperative computed tomography images. The air cells of the temporal bone were divided into five areas: periantral (anterior), periantral (posterior), periantral (medial), peritubal, and petrous apex. The number of areas with air cells before and after surgery was compared to evaluate temporal bone pneumatization after surgery. Results: A total of 63 patients, comprising 29 with CC and 34 with AC (pars flaccida; 23, pars tensa; 7, unclassified; 4), were evaluated. The median age of patients (18 males and 11 females) with CC was 5.0 (range, 2-15 years), while that of the AC group (23 males and 11 females) was 8 (range, 2-15 years). A significant difference in air cell presence was identified in the CC and AC groups after surgery (Mann-Whitney U, p < 0.001 and p = 0.003, respectively). Between the two groups, considerably better postoperative pneumatization was observed in the CC group. A correlation between age at surgery and gain of postoperative air cell area development was identified in the CC group (Spearman's rank-order correlation coefficient, r = -0.584, p < 0.001). In comparison with the postoperative pneumatization rate of each classified area, the petrous apex area was the lowest in the CC and AC groups. Conclusions: Newly developed air cells were identified in the temporal bones after CWU mastoidectomy for pediatric cholesteatoma. These findings may justify CWU tympanomastoidectomy, at least for younger children and CC patients, who may subsequently develop air cell systems after surgery.

Three-dimensional volumetric analyses of temporal bone pneumatization from early childhood to early adulthood in a South African population.

A debate exists on whether the size of temporal bone pneumatization is a cause or consequence of otitis media (a global disease burden). However, a normal middle-ear mucosa is a prerequisite for normal temporal bone pneumatization. This study investigated the size of temporal bone pneumatization with age and the normal distribution of air cell volume in different stages of human growth postnatally. A three-dimensional computer-based volumetric-rendering technique was performed bilaterally on 248 head/brain and internal acoustic meatus computed tomography images of slice thickness ≤ 0.6 mm consisting of 133 males and 115 females with age range 0-35 years. The average volume of infant (0-2 years) pneumatization was 1920 mm3 with an expected rapid increase to about 4510 mm3 in childhood (6-9 years). The result also showed a significant increase (p < 0.001) in the volume of air cells up to the young adult stage I (19-25 years), followed by a significant decline in young adult stage II (26-35 years). However, the females were observed to experience an earlier increase than males. Also, population differences were observed as the Black South African population group showed a higher increase in volume with age than the White and Indian South African population groups, though the volumes of the latter increased up to young adult stage II. This study concludes that the pneumatization of a healthy temporal bone is expected to continue a linear increase up until at least adult stage I. Termination of temporal bone pneumatization in an individual before this stage could signify pathologic involvement of the middle ear during childhood.

Communication between the temporomandibular joint articular space and the extradural space in patients with temporal bone pneumatization: implications for temporomandibular joint surgery

The pneumatization of the articular portion of the temporal bone is an anatomical variant that can modify the barrier between the articular space and the middle cranial fossa. Thus, this study aimed to identify the presence and degree of pneumatization, as well as the existence of pneumatic cell dehiscence towards the extradural or articular space determining whether it could lead to direct communication between the articular and extradural spaces. Hence, One-hundred skull computed tomography images were selected. The presence and extension of pneumatization were classified according to scores 0, 1, 2, and 3. Dehiscence towards extradural and articular spaces was recorded. In total, 200 TMJ from 100 patients were assessed and 40.5% of pneumatization cases were observed. The most prevalent score was 0 (restricted to the mastoid process), while the least prevalent score was 3 (extending beyond the crest of articular eminence). Dehiscence of the pneumatic cells towards the extradural space is more common than towards the articular space. One complete communication between the extradural and articular spaces was observed. Considering the results, it was concluded that to avoid neurological and ontological complications, awareness of the potential anatomical communications between articular and extradural spaces, particularly in patients with extensive pneumatisation, is necessary.

Role of mastoid pneumatization in predicting tympanoplasty results: Will it have the same importance in different age groups?

IntroductionThere are several factors that seem to affect the surgical success rate of tympanoplasty, one of them being the pneumatization of the contralateral mastoid. In the current literature, several studies have been published with classification proposals for temporal bone pneumatization pattern.This study aims to evaluate the role of mastoid air cell extension in relation to the sigmoid sinus in predicting the surgical success of tympanoplasty. Material and methodsThis case-control study was performed on patients diagnosed with chronic otitis media (COM) who underwent type I tympanoplasty. The study group did not close the tympanic membrane, or there was a retraction or lateralization of the graft. The control group consisted of patients with surgical success. ResultsNo statistically significant difference was found between groups regrading age, gender, perforation side/type, previous nasal surgery, and the presence of chronic otitis media in contralateral ear.A statistically significant difference was found when groups were compared in relation to the degree of pneumatization of the contralateral ear (p = 0.046), and this relationship does not seem to be influenced by age. ConclusionTo predict surgical success in terms of tympanic membrane closure in tympanoplasty, classification of contralateral ear pneumatization degree using the sigmoid sinus as a reference seems to be a valid and easy to apply method, and makes it possible to restrict the evaluation of pneumatization to the mastoid, a cell complex that does not seem to change with age.

Evaluation of temporal bone pneumatization using panoramic radiography and cone beam computed tomography

Aim: To evaluate the presence and characteristics of pneumatizations in the roof of the mandibular fossa and articular eminence by panoramic radiography and cone beam computed tomography (CBCT). Methods: This study analyzed CBCT images of the temporomandibular joint of 705 patients, In 60 exams, it was possible to compare tomographic with panoramic images. For cases where pneumatization was present, laterality and pattern of manifestation were considered. A chi-square test was used to compare the differences between CBCT and panoramic radiography in the diagnosis of pneumatization. Results: Descriptive analysis revealed a sample profile that was predominantly female (75.9%), with a mean age of 42.6 years (± 17.4). The presence of pneumatizations in the roof of the mandibular fossa and articular eminence in CBCT images was identified in 330 (46.8%) and 154 (21.8%) exams, respectively, and the most frequent pneumatization pattern was the multilocular type in both locations. Bilateral pneumatization was more prevalent in the roof of the mandibular fossa. Considering the analysis of 60 pairs of exams, in panoramic radiography, pneumatizations in the roof of the mandibular fossa and articular eminence were identified in 22 (36.7%) and 12 (20.0%) examinations, respectively. Regarding CBCT images, pneumatizations in the roof of the mandibular fossa was observed in 24 (40.0%) exams, while articular eminence was found in 14 (23.3%) images. There were no statistically significant differences between the proportion of pneumatization identified by panoramic radiography and CBCT (p &gt; 0.05). Conclusion: This study suggests that panoramic radiography may be an imaging method used to evaluate pneumatization in the temporomandibular joint region. Uniterms: Temporal bone. Temporomandibular joint. Panoramic radiography. Cone beam computed tomography.

Temporal bone pneumatization: A scoping review on the growth and size of mastoid air cell system with age.

The interest in the mastoid air cell system arose from the association between temporal bone aeration and otitis media. Its size and growth have been considered when planning chronic and middle ear surgeries. The objective of this review was to explore the literature on the size of mastoid air cells with age, highlighting various growth rates reported and mapping out areas yet to be fully understood for further research. A three-step systematic search was conducted for available literature on the subject matter viz; Google Scholar, Medline, Cochrane Library, and PubMed. Eligibility criteria guided the study selection, and eligible studies were subjected to appraisal using screening and quantitative criteria of mixed-method appraisal tool. A data extraction form was developed to extract information from eligible studies. Nine studies met the eligibility criteria. 55.6% of the included studies were conducted among the east and south Asian population, 33.3% were conducted among Scandinavians, and 11.1% in South America. Age groupings varied among studies; 33.3% utilized 1-year age grouping, 33.3% utilized 5-year age grouping, 11.1% utilized 10-year age grouping. In reporting the size of mastoid air cells across age groupings, 66.7% utilized area, 22.2% utilized volume, while 11.1% utilized both area and volume. Findings from this review showed that the mastoid air cells’ size with respect to age differs among populations of different origins. The most common measurements were the area of air cells. The highest growth rate was reported up to 30 years. Findings also show the influence of sex on the size of mastoid air cells and growth rate with age, as females were reported to have larger air cells with rapid growth until puberty. However, the male mastoid air cell system continues a steady growth after puberty and becomes larger. Information still lacks in the volume of air cells in pediatric pneumatization.

Cholesteatoma in Children with Sotos Syndrome.

Background : Sotos syndrome is a rare genetic disorder characterized by neurodevelopmental delay and excessive childhood growth including macrocephaly. In this study, we present our experience of children with Sotos syndrome and cholesteatoma.Methods: Retrospective case note review and cross-referencing with hospital picture archive and communication systems or cases identified from a prospective database of consecutive cholesteatoma surgeries.Results: A total of 400 children underwent surgery for acquired cholesteatoma and 5 (1%) had Sotos syndrome (1 bilaterally). In comparison, 42(11%) had cleft palate which is around 10 times more common than Sotos syndrome, 5 (1%) had Down syndrome, and 3 (1%) had Turner syndrome. The median age at primary surgery was 8 years old (3.5-10.9 years), 124 children with Sotos syndrome were identified in picture archive and communication systems (4% with cholesteatoma) of which temporal bone imaging was available in 86 (70%) at the median age of 9 years (0-17.2), and 33/86 (38%) had normal ears bilaterally on all imaging. Changes consistent with fluid or inflammation were present in 9/30 (30%) computed tomography and 24/72 (33%) magnetic resonance imaging scans. Development of mastoid pneumatization was impaired in 20/30 (67%) computed tomography and 8/72 (11%) magnetic resonance imaging scans. At 5 years, children with Sotos syndrome (33%) had greater recidivism than those with cleft palate (15%) (Kaplan–Meier log-rank analysis, P = .001)Conclusion: Children with Sotos syndrome appear to be at increased risk of developing acquired cholesteatoma. Impaired temporal bone pneumatization is a common incidental finding in Sotos syndrome in keeping with this risk. Further study of this previously unreported association may improve the understanding of pathogenetic mechanisms in cholesteatoma.

Persistent otitis media with effusion - an unusual type of nasopharyngeal adenocarcinoma

We present the case of a 41-year-old male patient that examined in the outpatient ENT Department of our hospital, reported a persistent otitis media for about six months. Despite medical therapy, his symptom did not improve. The suspicious of a nasopharyngeal mass was raised and the rhino endoscopy revealed a mucosal projection in the left fossa of the Rosenmuller. Computed tomography (CT) of temporal bone pneumatization showed a left mastoid cell occupation and a small projection in the left fossa of the Rosenmuller. The histological examination result of a biopsy of the lession that prepared under local anesthesia, revealed nasopharyngeal adenoid cystic carcinoma. Magnetic resonance imaging indicated the extent of the tumor. The positron emission tomography/computed tomography (PET/CT) scan staged the patient and concluded the diagnosis. The patient underwent both surgery and radiotherapy and addressed oncologists and radiotherapists for further treatment. The patient was diagnosed with lung and kidney metastasis. Adenoid cystic carcinoma is a rare type of adenocarcinoma with ominous prognosis. We always have to raise the suspicious of nasopharyngeal carcinoma, in patients with persistent otological symptoms, that do not improve despite therapy.

The Effect of Degree of Temporal Bone Pneumatization on Sound Transmission of Pulsatile Tinnitus Induced by Sigmoid Sinus Diverticulum and/or Dehiscence: A Clinical and Experimental Study.

Background: Although many studies have suggested that air cells may play an important role in sigmoid sinus diverticulum and/or dehiscence (SSDD)-induced pulsatile tinnitus (PT), the exact effects remain unclear. This study aims to quantitatively investigate the effect of different degrees of pneumatization of temporal bone on sound transmission from the sigmoid sinus to the tympanic cavity.Methods: In the clinical study, 25 patients were enrolled to measure the sound intensity and frequency of SSDD-induced PT. In the experimental study, sound inputs at different frequencies at the dehiscent sigmoid plate were measured and compared among realistic object models of different degrees of pneumatization, when sound intensity in the tympanic cavity was fixed as the level of the PT sound intensity sensed by patients.Results: The sound intensity sensed by PT patients was 34.0 ± 13.0 dB SPL, which represented the sound intensity in the tympanic cavity transmitted from the dehiscent sigmoid plate. In the experimental study, when sound received in the tympanic cavity was fixed at 34 dB SPL, the mean inputs of sound intensity at the dehiscent sigmoid plate were 46.9, 46.2, 45.2, 47.1, 57, 57.4, and 74.1 dB SPL in a hypo-pneumatized model; 42.6, 43, 41.5, 43.2, 47.3, 58.2, and 78.8 dB SPL in a moderately pneumatized model; 52.6, 52.8, 48.1, 61, 64.2, 82.4, and >87.3 dB SPL in a well-pneumatized model; and 47.2, 46.2, 45.4, 49.4, 54.9, 66.6, and 77.7 dB SPL in hyper-pneumatized model, with increased sound frequencies (125-8000 Hz). The mean sound transmission distances were 41.7 mm, 45.2 mm, 47.6 mm, and 48.4 mm in successively better pneumatized models.Conclusion: Sound reduces while passing through air cells and attenuation is lowest in the moderately pneumatized temporal bone, followed by the hypo- and hyper-pneumatized temporal bones, and the highest in the well-pneumatized temporal bone. Lower-frequency sound attenuation (≤1000 Hz) is less than that of higher-frequency sound (>1000 Hz).

Temporal Bone Pneumatization: Relationship With Sex and Variants of the Ethmoid and Sphenoid Bone.

Pneumatization variants of the temporal bone have a crucial importance in several surgical interventions. However, very few data are known about possible correlation with other pneumatization variants.Pneumatization of glenoid fossa, petrous apex, and infralabyrinthine portion of temporal bone was assessed in 200 computed tomography scans, equally divided between males and females (18-92 years). Pneumatization variants of the ethmoid (concha bullosa, agger nasi, pneumatized crista galli) and the sphenoid sinuses (pneumatized pterygoid processes, anterior clinoid processes, dorsum sellae, volume) were recorded as well.Differences in prevalence of each pneumatization type according to sex and side, among different portions of the temporal bone, and between temporal bone and the pneumatized variants of the ethmoid bone and sphenoid sinuses, were assessed through chi-square test (P < 0.05). Differences in sphenoid volume among different pneumatization degrees of the temporal bone were assessed through 1-way analysis of covariance test (P < 0.05).Pneumatization of the petrous apex and the infralabyrinthine portion was significantly more frequent in males than in females, whereas pneumatization of the glenoid fossa was more often observed on the right side (P < 0.05). Variants of the temporal bone are all related one with each other in males, whereas in females only the relationship between pneumatized petrous apex and infralabyrinthine portion was found. Moreover, in females the pneumatized petrous apex was related with pneumatized anterior clinoid process, and the pneumatized infralabyrinthine portion was related with the sphenoid sinus volume.Results may be useful for predicting these important variants in planning surgical interventions of the cranial base.

Association of Temporal Bone Pneumatization and Dehiscence of Facial Nerve Canal

Introduction: Facial nerve runs an extensive and complicated course through the temporal bone. Integrity of this nerve is affected by the anatomy of temporal bone. Hence, in-depth knowledge of facial canal and its surrounding structures is of utmost importance to avoid any iatrogenic injury during surgery of the middle ear. Temporal bone pneumatization has a great influence on pathogenesis and prognosis of temporal bone diseases. Hence, this study was planned to observe the pneumatization status of the temporal bone and whether there is any association between pneumatization of temporal bone and dehiscence of facial canal. Materials and Methods: The present study was conducted on 30 formalin-fixed adult temporal bones. Dissection of temporal bone was done in the Anatomy Department, TMMC and RC, TMU, Moradabad. Various cells groups were observed in the temporal bones. Facial canal was exposed, and any dehiscence present was then noted. Results: Out of total temporal bones studied, 20 belongs to the right side and 10 of the left side. Pneumatization status of bones was observed by the assessment of different cells present in the bone. Out of 30 bones, 19 (63.3%) bones were well pneumatized, in which 14 bones were of right side and five were of left side. About 11 (36.6%) bones were poorly pneumatized. In which, six were of the right side and five of the left side. In this study, dehiscence of the facial canal was observed in 9 (30%) temporal bones in which eight bones were well pneumatized and one bone was nonpneumatized. In our study, 21 (70%) bones showed no or insignificant dehiscence. Fisher exact test and Spearman's correlation test were applied to observe any association between the two variables. Conclusion: No association exists in between pneumatization of temporal bone and dehiscent facial nerve canal.

The Relationship Between Temporal Bone Pneumatization Pattern and Sinus Mucosal Thickness Grading on Computed Tomography Scans of Paranasal Sinuses.

The relationship between temporal bone pneumatization (TBP) pattern and sinus mucous thickness grading on computed tomography scans of paranasal sinuses was investigated. In this cross-sectional study, a total of 200 temporal bones and paranasal sinuses were evaluated in CT scans of 100 patients with chronic sinusitis (CRS). The mucosal thickness of paranasal sinuses was classified into two groups (0-6 and 7-12) according to the Lund-Mackay (LM) staging system. Also, pneumatization patterns of petrous apex and perilabyrinthine regions were classified according to Jadvah et al. method. Data were analyzed using Chi-square and Fisher's exact tests. The most common pneumatization pattern in the petrous apex was pattern A (49.5%) and in the perilabyrinthine region was pattern B (50%). In the petrous apex, the highest frequencies of pattern A (51.7%) and pattern C (24.6%), among other pneumatization patterns, were found in score range of 7-12 and 0-6, respectively, which was statistically significant (P = 0.017). Although in the perilabyrinthine region, the highest frequencies of pattern A (24.1%) and pattern C (32.7%) were in LM score ranges of 7-12 and 0-6, respectively, no significant difference was found (P = 0.589). The petrous apex pneumatization decreases with an increase in the severity of CRS, which can be in response to the eustachian tube dysfunction and common pathogens with CRS. A similar relationship was also found in the perilabyrinthine region, although it was not statistically significant. No significant relationship between TBP and severity of CRS was found in the age and sex groups.

Temporal Bone Anatomy in Superior Semicircular Canal Dehiscence: A Case Control Study on Bone Pneumatization and the Level of Middle Cranial Fossa.

To assess for any association between the presence of superior semicircular canal dehiscence (SSCD) and temporal bone pneumatization and the height of middle fossa in symptomatic patients. Retrospective case-control study. Tertiary, university referral center. Symptomatic patients with SSCD and a matched group of non-SSCD patients. High-resolution computed tomography of the temporal bones. We graded the temporal bone pneumatization using the Virapongse classification and measured the distance between the middle fossa and the lateral semicircular canal on coronal plane at the most anterior aspect of the lateral and superior semicircular canals. We statistically compared all parameters (level of significance 0.05). We enrolled 30 patients with SSCD, (males = 13, females = 17) with mean age of 47 years (SD: 26). The matched control group had similar baseline characteristics (p > 0.05). Grade 4 pneumatization was noted in 83.3% (n = 25) of SSCD patients with the remainder having grade 3. In the control group, 46.6% (n = 14) had a grade 4 pneumatization, 36.6% (n = 11) grade 3 and 16.6 5 (n = 5) grade 2. This difference was statistically significant (p = 0.003). The difference in the height of the middle cranial fossa between the two groups was also statistically significant (mean 3.80 [SD: 0.84] in SSCD group and 4.68 mm [SD: 0.85] in the control group; p < 0.0001). We found better-pneumatized mastoids in patients with SSCD, indicative of a direct association between temporal bone pneumatization and SSCD. Additionally, the middle fossa dura is lying significantly lower in patients with SSCD, factor of surgical importance.

Quantitative three-dimensional computed tomography analysis of sinus tympani volume in temporal bones with petrous apex pneumatization

ObjectiveTo investigate the association between sinus tympani volume and petrous apex pneumatization in this retrospective-archival temporal bone computed tomography study. MethodsWe included 46 temporal bones with pneumatized petrous apex from 26 patients and 52 temporal bones without petrous apex pneumatization from 26 other patients. Using OsiriX software for MacOS (version 3.8.1, Pixmeo), we measured the volumes from three-dimensional sinus tympani models and compared the sinus tympani volumes and depths between the temporal bones with and without pneumatized petrous apex. ResultsAmong 150 patients totally reviewed, 26 (17.3%) had petrous apex pneumatization. The median sinus tympani volume was 16.05 (5.6–59.7) mm3 in temporal bones with pneumatized petrous apex and 8.7 (1.76–59.7) mm3in temporal bones without. The sinus tympani volume was significantly greater in temporal bones with pneumatized petrous apex compared to those without (p < 0.001). Additionally, temporal bones with pneumatized petrous apex had a significantly deeper sinus tympani [median depth = 2.17 (0–3.04) mm] compared to the temporal bones without [median depth = 1.69 (0–3.73) mm] (p = 0.045). We found that petrous apex pneumatization was associated with deeper and larger sinus tympani. ConclusionPatients with pneumatized petrous apex had a greater sinus tympani volume associated with the increased risk of residual cholesteatoma.

Morphometry of the Digastric Ridge and Its Significance for Mastoid Surgeries-A Cadaveric Study.

Digastric ridge (DR) is an important landmark to locate facial nerve (FN) and sigmoid sinus for mastoid surgeries and transmastoid approaches. We aim to look for the effect of temporal bone pneumatization on the morphometry of the DR and its relation to the adjoining structures. Temporal bones were harvested from unclaimed cadavers after the approval of the ethical committee. The dissection of the temporal bones was performed under a microscope, and the length of the DR and the distance between the mastoid segment of the FN and the anterior end of DR (FN-DR distance) were measured using a digital caliper. Stata version 14.0 was used to perform the statistical calculations. Ninety-three temporal bones were microdissected (right:left = 47:46; well pneumatized:poorly pneumatized = 58:35). Mean length of the DR was 17.1 mm and was significantly longer in well-pneumatized bones (P = .0000). The mean distance between the anterior end of the digastric ridge and the mastoid part of the facial nerve was 4 mm. The distance was significantly more in well-pneumatized bones. Prominence and the length of the DR, as well as the FN-DR distance, are significantly more in well-pneumatized bones compared to poorly pneumatized bones. This finding has potential surgical implications with reduced risk of injury to the FN resulting from a conspicuous DR in well-pneumatized bones.