Do Decreased Mastoid Pneumatization, Bilateral Involvement and Eustachian Tube Function Affect the Success of Type 1 Tympanoplasty?

Aim

The surgical success rate of tympanoplasty appears to be influenced by a number of variables. Eustachian tube dysfunction has been shown as one of the factors causing failure in tympanoplasty. It is known that bilateral disease and decreased in mastoid pneumatization are associated with Eustachian tube (ET) dysfunction. In this study, the relationship between the success of type 1 tympanoplasty and mastoid pneumatization, bilateral disease and ET function was investigated.

Materials and Methods

A total of 44 patients who were operated for chronic otitis media in our clinic were included. The information of the patients was obtained retrospectively, the direction of the disease (bilateral/unilateral), the status of the graft (intact/perforated), mastoid pneumatization status, and hearing levels (preoperative/postoperative 6th month) were noted. Automatic Williams test was used to tympanometrically evaluate ET functions (ETF) in postoperative period. The relationship between tympanoplasty success and mastoid pneumatization, bilateral disease and ETF was investigated by statistical analysis.

Results

The disease aspect was found bilateral in 34.1% (n = 15) of the cases, and unilateral in 65.9% (n = 29) of the cases. Mastoid pneumatization was decreased in 52.2% (n = 23) of the cases, and normal in 45.4% (n = 20). The preoperative air-bone mean difference (gap) of the cases with decreased mastoid pneumatization was found to be statistically significantly higher than the cases with normal mastoid pneumatization (p < 0.05). The closure of the postoperative air-bone gap in patients with unilateral disease direction was found to be statistically significantly higher than in patients with bilateral disease direction (p < 0.05). Also we found significantly worse ET functions both in unilateral and bilateral disease.

Conclusion

Preoperative air-bone gap average is higher in ears with decreased mastoid pneumatization, and postoperative air-bone gap closure is higher in unilateral patients. Mastoid ventilation does not make a significant difference in the success of type 1 tympanoplasty. On the other hand, our results support that ET dysfunction can be effective in the occurrence of chronic otitis media (COM).

Computed tomography-based assessment of sphenoid sinus and sella turcica pneumatization analysis: a retrospective study

Background

A preoperative three-dimensional examination of the sphenoid sinus anatomy, its pneumatization pattern, and its relevance to neighboring neurovascular constructions is crucial to preventing possible complications. In this study, the aim was to evaluate the relationship between sphenoid sinus pneumatization types and the sella turcica using computed tomography (CT).

Methods

CT data from 420 patients referred to the Department of Dentomaxillofacial Radiology were evaluated retrospectively. Sella pneumatization types were classified as conchal, presellar, incomplete sellar, and complete sellar, and they were evaluated. Obtained data were evaluated using the IBM SPSS 25.0 (Armonk, New York, USA) package program.

Results

CT images of 420 individuals, including 174 women and 246 men with a mean age of 43.87 ± 17.58 years, were included in the study. When the sella turcica morphologies were evaluated, the most widespread morphological type was irregularity in the posterior part of the dorsum sella, in 51.2% of cases. In addition, a statistically significant correlation was found between the pneumatization of the sphenoid sinus and the morphological types of sella (p < 0.05).

Conclusion

In this research endeavor, the predominant observation comprised the complete sellar sphenoid sinus pneumatization type, exhibiting irregularity in the posterior aspect of the dorsum sella, representing one of the sellar types. Notwithstanding, it is imperative to conduct additional investigations to establish the generalizability of the present study's findings.

An inter-observer assessment of mastoid pneumatization and degree classification using sigmoid sinus: comparing two levels of temporal bone computed tomograms

BACKGROUND

The degree of mastoid pneumatization of the temporal bone (TB) has been implicated in the pathogenesis of TB diseases and surgical implications, and planning of a few otologic surgeries. However, there is lack of consensus in the classification of the degree of pneumatization. This study aimed to suggest a simple, quick, and less-burden classification system for assessing and rating the degree of pneumatization by comparing two levels of TB computed tomographs (CTs) using the SS as a reference in an inter-observer assessment among otologists.

METHODS

This was a randomized pilot survey among otologists. A questionnaire consisting of different axial CTs of TB taken at two levels: the level of malleoincudal junction (MIJ) and the level of lateral semicircular canal (LSCC), with different pneumatization patterns, was used to assess participants' impressions of the degree of pneumatization. The terms "hypo-," "moderate," "good," and "hyper-" pneumatization were listed as options to rate their impressions on the degree of mastoid pneumatization of the TB images using the SS as a reference structure. Likert scale was used to assess their level of agreement or disagreement with using SS as a reference in evaluating mastoid pneumatization.

RESULTS

Participants who correctly rated images taken at the level of LSCC according to their respective degree of pneumatization were significantly higher (p < 0.05) regardless of their year of experience compared to those that correctly rated corresponding images taken at the level of MIJ. A 76% positivity in their level of agreement with the use of sigmoid sinus in evaluating mastoid pneumatization was observed on the Likert-scale chart.

CONCLUSION

Findings from this study suggest that evaluating air cells around the SS at the level of LSCC on CTs could be easier in assessing and classifying the degree of mastoid pneumatization.

Factors affecting the location of sphenoid sinus ostium: a binary logistic regression analysis

BACKGROUND

Sphenoid sinus is a type of sinus surrounded by critical structures so that its injury potential to induce complications during surgery. The purpose of this study was to investigate the factors affecting the location of the sphenoid sinus natural ostium (SSO) to provide valuable data for endoscopic sinus surgery.

METHODS

Ostiomeatal unit (OMU) computerized tomography (CT) was performed on 198 subjects. Across the left and right sides, 396 evaluation results were obtained. The vertical distance to determine the location of the SSO was analyzed based on Lines 1, 2 and 3 on the sagittal image. The horizontal distance was analyzed based on Lines 4 and 5 on the axial image. The upper, lower, medial and non-medial borders were defined according to the location of the SSO. The presellar, sellar and postsellar types were categorized according to the level of sphenoid sinus pneumatization (SSP) on the sagittal image. The presence and absence of Onodi cells were defined on the coronal image. Binary logistic regression analysis was performed to investigate each factor.

RESULTS

As the rostrum width of the SSO on the horizontal position increased, the position toward non-medial boarder increased by 4.902 times so that the natural ostium showed a trend of lateralization. For the postsellar type, compared to the presellar type, the position toward the non-medial boarder decreased by 0.223 times, indicating that the postsellar type had the natural ostium showing a trend of medialization. In the presence of Onodi cells, the position toward the lower boarder increased by 2.599 times with a significant association.

CONCLUSIONS

The results in this study indicated that the presellar type of SSP had the natural ostium exhibiting lateralization with an increase in the rostrum width, whereas the postsellar type had the natural ostium exhibiting medialization with a decrease in the rostrum width. Based on these findings, the methods to widen the natural ostium may be diversified.

Correlation Analysis of the Pneumatization of the Supraorbital Ethmoid Cell and the Position of the Anterior Ethmoidal Artery

OBJECTIVES

This study aimed to measure the supraorbital ethmoid cell (SOEC) and characterize the relationship between the degree of SOEC pneumatization and the position of the anterior ethmoidal artery (AEA) in relation to the skull base.

METHODS

Computed tomography (CT) scans of 100 patients were analyzed. The correlation between the pneumatization of SOEC and the distance of the AEA from the skull base was explored by Spearman's correlation rho efficient test.

RESULTS

The distance of the AEA from skull base was 3.10 (2.60,3.60) mm in patients with SOEC compared with 0.6(0.40,2.10)mm in those without(P < .001). In 50.5% of the patients, the AEA was located below the skull base; the incidence of this localization was significantly higher in those with SOEC than in those without (78.79%vs22.77%, P < .001). Compared to female patients, male patients owned greater SOEC height (9.65vs8.20mm, P = .007). The SOECs volume (r = 0.45, P < .001), height (r = .30, P = .003), and transverse diameter (r = 0.28, P = .005) were all significantly correlated with the distance of the AEA from the skull base.

CONCLUSIONS

The pneumatization of SOEC critically impact the distance between the AEA and skull base. The higher the degree of pneumatization, the farther from the skull base the AEA will be, increasing the risk of complications during nasal endoscopic surgery. These results provide an important reference for protecting the AEA during nasal endoscopic surgery.

Sinus tympani revisited for planning retrofacial approach-radiologic study in pneumatized temporal bones and its surgical implications

BACKGROUND AND PURPOSE

Retrofacial approach (RFA) is an access route to sinus tympani (ST) and it is used in cholesteatoma surgery, especially when type C ST is encountered. It may also be used to gain an access to stapedius muscle to assess the evoked stapedius reflex threshold. The primary object of this study was to evaluate the morphology of sinus tympani and its relationship to facial nerve (FN) and posterior semicircular canal (PSC) in context of planning retrofacial approach in pneumatized temporal bones.

METHODS

CBCT of 130 adults were reviewed. The type of sinus tympani was assessed according to Marchioni's classification. Width of entrance to sinus tympani (STW), depth of ST (STD), distance between the posterior semicircular canal and facial nerve (F-PSC), distance between the latter plane to the floor of ST at the right angle (P-ST) were measured at level of round window (RW) and pyramidal ridge (PR).

RESULTS

All of the bones were well-aerated and classified in Dexian Tan pneumatization group 3 or 4. Type B of ST is dominant (70.8%) in adult population with no history of inflammatory otologic diseases, followed by type C (22.7%) and then type A (6.5%). The depth of ST (STD) presented significant deviations (ANOVA, p < 0.05) among all three types. STW reaches greater values on the level of PR. F-PSC does not correlate with type of ST. In over 75% of examined type C sinus tympani the distance P-ST was less than 1 mm.

CONCLUSIONS

The qualitative classification of the sinus tympani into types A, B and C, introduced by Marchioni is justified by statistically significant differences of depth between individual types of tympanic sinuses. The STW distance reaches greater values inferiorly-it may suggest that RFA should be performed in infero-superior manner rather than opposite direction. Preoperative assessment of temporal bones CT scans gives very important information about size of sinus tympani and distance between FN and PSC.

Variability of the retrotympanum and its association with mastoid pneumatization in cholesteatoma patients

PURPOSE

This study aimed to investigate the variability of the retrotympanum in patients undergoing surgical treatment for cholesteatoma.

METHODS

We included 59 ears of patients undergoing middle ear surgery for cholesteatoma who had preoperative computed tomography scans. A retrospective analysis of the medical records was conducted. The sinus tympani (ST), subtympanic sinus (STS) and facial recess (FR) were classified into types A-C based on the relationship of their extension to the facial nerve. The mastoid and petrous apex were assessed and categorized as normal pneumatized or sclerotic.

RESULTS

Type A extension was the most frequently found in all sinuses (ST 64%, FR 77%, STS 69%), Type B extension was found more often in ST (34%) and STS (24%) than in FR (15%). A very deep extension was found only rarely (ST 2%, FR 8%, STS 7%). A sclerotic mastoid was found in 67% of cases. Those cases showed a statistically significant difference regarding retrotympanum pneumatization when compared with normal mastoid.

CONCLUSION

The most frequent variant of retrotympanic pneumatization in relation to the facial nerve was type A in all subsites in cholesteatoma patients. The variability among patients with cholesteatoma is different to previously published results in healthy subjects. Moreover, the pneumatization of the retrotympanum is associated with mastoid pneumatization.

Demonstration of the inferior intercavernous sinus is closely linked to the extent of pneumatization of the sphenoid sinus: useful information for the pituitary surgeon

PURPOSE

To study the utility of T2-weighted MRI sequences in the identification of the inferior intercavernous sinus (IICS), a potential source of bleeding during transsphenoidal surgery of pituitary adenomas.

METHODS

Pituitary sagittal T1W and coronal T2W MRI sequences were analyzed in 237 consecutive patients, after the exclusion of postoperative MRIs and those revealing an empty sella or a pituitary macroadenoma. Sphenoid sinus pneumatization was defined as incomplete (group 1) if it did not reach the nadir of the sella turcica, as complete (group 2) if it extended beyond the nadir of the sella or asymmetric (group 3), when only one side of the sinus was completely pneumatized.

RESULTS

In Group 2 (70% of the patients), the IICS was rarely visualized on coronal T2W MRI (6/167 patients-3.6%), whereas in Group 1 it was identified in nearly all patients (55/57 patients - 96.5%, p < 0.001). In Group 3, the IICS was only visible above the non-pneumatized part of the sphenoid sinus.

CONCLUSIONS

The IICS can be identified on coronal T2W images in patients with an incompletely pneumatized sphenoid sinus, but very rarely in patients with a totally pneumatized sinus. This information can help to increase awareness among pituitary surgeons of the need to potentially manage IICS bleeding during transsphenoidal surgery in patients with an incompletely pneumatized sphenoid sinus.

A Study of Anatomical Variations of Sphenoid Sinus on CT PNS: Our Experience

Sphenoid sinus anatomical variations are very common, its prior knowledge is very essential while doing skull base surgery to avoid catastrophic complications which might be due to damage of surrounding neurovascular structures. This retrospective observational study was done to examine the different anatomical variations of sphenoid sinus on CT PNS which was conducted in KMCH, Katihar from May 2019 to April 2020 involving 60 cases above 15 years of age who had undergone CT PNS. Sellar type of pneumatization was seen in 66.7%, pterygoid process pneumatization was seen in 25%. Single septation was present in 43.3%, septum attached to optic nerve was seen in 33.3%, onodi cell was seen in 36.7%, anterior clinoid process pneumatization was seen in 13.3% of cases. By this study we came to a conclusion that preoperative assessment of sphenoid sinus anatomy and its variations is mandatory to avoid surrounding neurovascular structure damage and CSF leak.

Craniocervical fractures management in case of craniocervical pneumatization: case report and review of the literature

INTRODUCTION

Extensive craniocervical pneumatization (CCP) refers to an abnormal pneumatization extended from the temporal bone into adjacent bone structures, especially the skull base and the craniocervical junction. The etiology remains controversial; however several studies reported a correlation with recurrent Valsalva maneuvers or Eustachian tube dysfunction. Although some cases requiring surgical treatment have been reported, conservative treatment remains the gold standard. The authors aimed to describe a case of CCP, complicated by a spontaneous fracture of a pneumatized left occipital condyle. Furthermore, they reviewed all previously reported cases of fractures in CCP in order to propose a standardized approach to this pathology.

METHODS

A total of 148 studies were retrieved. Of those, 23 studies (including 26 patients in addition to our case) were included in the review. These studies consisted of case reports or small case series (up to 3 patients).

RESULTS

In 3 patients (11.1%), bone pneumatization involved C0; all remaining patients had both C0 and C1 pneumatization, while in 7 cases (25.9%), an extension to C2 and/or C3 was reported. Radiological follow-up was performed in 20 patients (74.1%), showing in all of the cases either stability (6 patients, 22.2%), improvement, or complete resolution (6 patients, 22.2% vs 8 patients, 29.7%). Two patients underwent surgical intervention.

CONCLUSIONS

This review suggests that fractures secondary to CCP are extremely rare and are associated to a good clinical and radiological outcome with conservative treatment. Ear, nose, and throat (ENT) evaluation is recommended to detect cases who need treatment for a subjacent middle ear disease.

The pneumatization of the sphenoid sinus, its variations and relations with surrounding neurovascular anatomic structures: A computerized tomography study

INTRODUCTION AND OBJECTIVES

The wide range of variability of SS pneumatization and relation with surrounding structures can result in serious complications; seeing that, the assessment of regional anatomy is essential for both surgeons and radiologists. We mainly aim to reveal the possible correlation between the SS pneumatization types and protrusion/dehiscence of the adjacent neurovascular structures in a larger population by using computerized tomography (CT) images.

METHODS

The type of SS pneumatization (I-IV), pneumatization of anterior clinoid process (ACP), greater wing of sphenoid (GWS), and pterygoid process (PP) was evaluated. Protrusion and dehiscence of ICA, ON, MN, and VN was noted.

RESULTS

1003 patients were included into the study. ICA, ON, and MN protrusions were not seen in patients with the type I or II SS on both sides. These protrusions were most frequently seen along with the type IV SS on both sides (p < 0.05). ICA, ON, MN, and VN dehiscence was not found in any patients with the type I SS. The rate of ICA protrusion increased with presence of GWS and PP; ICA dehiscence was found to be positively correlated with ACP, GWS, and PP pneumatization.

CONCLUSIONS

Variations, either amount or the extent, of the pneumatization of the SS are related with the presence of protrusion/dehiscence of ICA, ON, MN and VN. Knowing and reporting these relations can decrease the rate of complications during skull base surgery.

Changes in pneumatization of the maxillary air sinuses in Korean adults following biomimetic oral appliance therapy

Objective

For the treatment of obstructive sleep apnea in adults, mandibular advancement devices (MADs) are often used. Since adults with a prognathic mandibular phenotype are at risk of developing an unfavorable facial profile, midfacial development using biomimetic oral appliance therapy might provide a suitable alternative. However, the effect of this procedure on the maxillary air sinuses is unknown; therefore, changes in sinus pneumatization were investigated in this study.

Methods

After obtaining informed consent, 16 consecutive Korean adults with midfacial hypoplasia had 3D cone-beam (CB) CT scans taken, and biomimetic upper appliances (DNA appliance®, Vivos Therapeutics, Inc., USA) were constructed.

All subjects were instructed to wear the device 12–16 h/day. Each month, examination for the progress of midfacial development was recorded. Post-treatment, a follow-up 3D CBCT scan was undertaken with no device in the patient's mouth. Pre- and post-treatment linear and volumetric measurements were obtained using appropriate software, and compared statistically using t-tests.

Results

The mean age of the sample was 25.0 yrs ± 8.7. The mean treatment time was 15.5 mths ± 5.2. Post-treatment, the transpalatal bone width increased from 35.3 mm ± 3.0 to 38.5 mm ± 2.0 (P < 0.001); the maxillary air sinus volume on the left side increased from 18.8 cm³ ± 6.5 to 20.0 cm³ ± 6.0 (P < 0.05), and from 18.5 cm³ ± 5.7 to 19.7 cm³ ± 5.8 (P < 0.05) on the right side.

Conclusions

Biomimetic oral appliance therapy may be able to increase the maxillary air sinus volume in adults. In view of these preliminary findings, further studies on the effect of enhanced pneumatization on paranasal sinus function and sleep parameters are warranted.

Cone Beam Computed Tomography Analysis of Sphenoid Sinus Pneumatization and Relationship with Neurovascular Structures

Background

The sphenoid sinus is considered as the most variable pneumatized structure of the skull.

Purpose

The aim of the present study was to determine the prevalence of the Onodi cell as well as to evaluate the relationship between the sphenoid sinus type of pneumatization and the presence of surrounding neurovascular protrusion using cone beam computed tomography (CBCT).

Methods

The CBCT images of 500 patients/996 sides [203 males (40.6%) and 297 females (59.4%)] were analyzed in this study. The type of sphenoid sinus pneumatization, prevalence of internal carotid artery (ICA) and optic nerve (ON) protrusion and dehiscence, and also the frequency of Onodi cell were assessed.

Results

The percentages of the conchal, presellar, sellar, postsellar (a), and postsellar (b) types of pneumatization were 1%, 11.5%, 35.5%, 38.9%, and 13.1%, respectively. The more the sphenoid sinuses pneumatized, the greater the frequency of ON and ICA protrusion and dehiscence of their wall to the sinus. The prevalence of Onodi cell was 38.8%. A significant correlation was found between ON dehiscence and the presence of Onodi cells.

Conclusion

The present study demonstrated a significant relationship between the sinus type and frequency of neurovascular protrusions. Therefore, the sphenoid sinus extent of pneumatization might be useful in predicting the risk of iatrogenic damage to the surrounding structures.

Intercarotid artery distance in the pediatric population: Implications for endoscopic transsphenoidal approaches to the skull base

OBJECTIVE

Comprehensive quantitative evaluation of the intercarotid artery distance (ICD) in the pediatric population has not been sufficiently explored. This study aims to measure the minimal ICDs at multiple levels of the skull base to assess changes in the ICD during development.

METHODS

Measurement of the ICDs between the paired paraclival, parasellar, and paraclinoid segments of the internal carotid artery (ICA) was performed on coronal MRI from 540 patients ranging from 0 to 17 years old (n = 30 for each age). Comparison of these indices in the very young (0-5 years, Group 1) and young (6-17 years, Group 2) patients, and assessment of the degree of sphenoid sinus pneumatization was employed.

RESULTS

The narrowest ICD was located at the paraclinoid ICAs in the vast majority of cases (89.44%). When comparing the ICDs in very young age patients with the ICDs of 17 years old subjects, a statistically significant difference was found at the paraclival (ages 0-5), parasellar (ages 0-2), and paraclinoid (ages 0-4) ICDs (p < 0.05). Comparison of the ICDs between the intergroups (Group 1 and 2) also demonstrated a statistically significant difference (p < 0.0001). Pneumatization of the sphenoid sinus was initially noted to start at 3 years of age, and there were no patients with a non-pneumatized sphenoid sinus identified after 7 years of age in our cohort.

CONCLUSION

Measurement of ICDs at multiple levels provides a valuable reference for EEA procedures in the pediatric population. While the ICD may be largely stable in the pediatric population after 5 years of age, additional anatomic factors may restrict transsphenoidal access in very young patients (0-5 years).

Classification of crista galli pneumatization and clinical considerations for anterior skull base surgery

Cerebrospinal fluid (CSF) leakage caused by frontal sinus exposure is a serious complication in the basal interhemispheric approach (BIHA). Crista galli pneumatization (CGP) is often observed on preoperative computed tomography (CT) scan. The aim of this study was to classify and describe variations in anatomical measurements of CGP. We examined CT images of 300 patients with brain tumors to assess the morphology and incidence of CGP. Crista galli were classified according to their location relative to the cribriform plate and the presence of pneumatization. The paranasal sinuses were investigated as the origin of CGP. We assessed 24 patients using the BIHA for skull base tumors; these patients were included as clinical cases to assess the range of skeletonization of the crista galli and determine the route of CSF leakage in the other 276 patients. CGP was found in 28/300 CT scans, including upper, middle, and lower type CGPs. The origin of CGPs was the frontal sinus or ethmoid sinus. All CGPs were localized in the anterior half of the crista galli. In the 24 consecutive clinical cases, there were 13 tuberculum sellae meningiomas, 3 craniopharyngiomas, and 8 with other pathologies. The preoperative crista galli height was 12.3 mm and the distance from the top of the skeletonization to the cribriform plate was 5.2 mm. CGP originating from the paranasal sinuses can lead to CSF leakage. In cases where CGP originates from the ethmoid sinus, care should be taken to seal the exposed crista galli intradurally.

Comparative analysis of dimensional alterations following extraction of maxillary molars using three-dimensional images' superimposition: a CBCT study

The aims of this study were to (i) evaluate the bone alterations following maxillary molar extraction and (ii) identify the factors associated with bone alterations using a tomographic analysis. Cone Beam Computer Tomographies (CBCTs) of 17 subjects with 25 maxillary molars were analyzed, before and, in average, 12 months following extraction. Fifty CBCTs were segmented as 3D models that were used as reference for analysis. Cross-sectional planes were established to measure the dimensional changes in the vertical, horizontal aspects, and the area of the alveolar bone. Associations between root divergence, initial bone location related to the maxillary sinus, and the thickness of buccal and palatal bone at baseline was assessed using mixed-effect models. Overall, the average reduction in vertical bone height was 35.23% (2.61 ± 1.76 mm). The mean reduction of area of alveolar process and horizontal bone width were 18.89% (56.08 ± 44.23 mm²) and 65.10% (8.33 ± 4.51 mm), respectively. There was a marginal significant association between horizontal bone changes and the thickness of palatal bone (p = 0.05). The results of the present study indicated that following maxillary molar extraction, significant dimensional changes occur in both the vertical and horizontal directions. The vertical changes were mainly attributed to remodeling on the coronal aspect of the alveolar ridge and sinus pneumatization was rare.

A new classification proposal for sphenoid sinus pneumatization: a retrospective radio-anatomic study

OBJECTIVES

The sphenoid sinus variations are very diverse and the frequency of these sinus variations is high. During operations involving the sphenoid sinus, such as pituitary surgeries, the surgeon should have detailed information about these variations. The aim of this study is to reclassify the sphenoid sinus pneumatizations in detail and to evaluate the incidence of pneumatization types in a Turkish population according to this classification.

METHODS

New classification proposal was made. In accordance with the proposed new classification, sphenoid sinus pneumatizations were evaluated on CBCT images.

RESULTS

When the posteroanterior pneumatization of 128 patients was evaluated; 2.3% conchal, 3.9% presellar, 35.9% sellar, and 57.8% postsellar pneumatization was detected. Of these cases, 28.9% had anterior pneumatization on the right and 23.4% on the left. When lateral direction pneumatizations were evaluated, lateral body type was found to be the most common on both right (44.1%) and left (42.5%) sides.

CONCLUSION

In this study, sphenoid sinus pneumatizations were evaluated three-dimensionally with the help of CBCT, and a new classification suggestion was made to eliminate the classification confusion we encountered in our previous studies. Pneumatizations and variations can affect the field of operation and even change planning. It should be taken into account that the paranasal sinuses may have variations due to their surgical importance and their close association with many vital structures.

Anatomical relationship of pterygoid process pneumatization and vidian canal

Introduction

The vidian canal acts as landmark for the identification of the petrous carotid artery, especially during extended endoscopic endonasal approaches in cranial base surgeries. In order to localize the canal and to understand the relationship of pneumatization of pterygoid process to the type of vidian canal, this study was designed.

Objectives

The objective was to describe the anatomical relationship of pneumatization of the pterygoid process with types of vidian canal. The length of vidian canal, relationship to medial plate of pterygoid process and relationship to the petrous part of internal carotid artery were evaluated.

Methods

Head computer tomography scans of 52 individuals for suspected paranasal pathology were studied. The degree of sphenoid sinus pneumatization, pterygoid process pneumatization and types of vidian canal (type 1, 2 and 3) were noted. The length of vidian canal, distance from the plane of medial pterygoid plate and relation of vidian canal to the junction of petrous and Gasserian (ascending) part of internal carotid artery was noted.

Results

46 (92%) sphenoid sinuses were of the sellar variety. Out of 104 sides that were studied, 57 sides demonstrated a pneumatised pterygoid process and 47 were not pneumatised. In 49 sides (47.1%) the vidian canal was on the same plane as that of the medial pterygoid plate in the coronal section. The vidian canal partially protruded into the sphenoid sinus (type 2) was the most common type (50.9%), found both on right and left sides. There is a statistically significant association between the pterygoid process pneumatization and occurrence of type 2 and type 3 vidian canal configuration. The average length of the vidian canal was 16.16 ± 1.8 mm. In 96 sides, the anterior end of vidian canal was inferolateral to petrous part of internal carotid artery in the coronal plane.

Conclusion

Pneumatization of the pterygoid process indicates either type 2 or type 3 vidian canal configuration.

Evaluation of pneumatic cavities surrounding temporomandibular joint by cone beam computed tomography

OBJECTIVE

The purpose of this study was to detect the prevalence and characteristics of pneumatization in the roof of the glenoid fossa (PRGF) and articular eminence (PAT) by using cone beam computed tomography (CBCT) images.

MATERIAL AND METHOD

CBCT images of 378 patients (756 TMJ) were analyzed to determine the PRGF and PAT. Twenty-eight patients were excluded due to some reasons such as trauma, degeneration, previous surgical operation of temporomandibular joint (TMJ). Pneumatization was detected in 297 of 350 patients, but not pneumatization in 53 patients. Age, gender, laterality (unilateral, bilateral) and lacunarity (unilacunar, multilacunar) were recorded. Unilateral types were also noted as right and left localization. Chi-square test was used to evaluate relationship between pneumatization and gender, lacunarity and laterality.

RESULTS

PRGF and/or PAT were diagnosed in 491 (70%) TMJ components whom 178 (51%) were male and 172 (49%) were female with mean age of 40.38±18.34 years. In total, 103 (35%) of the patients had unilateral and 194 (65%) patients had bilateral pneumatization.

CONCLUSION

CBCT provides reliable and precise images to detect pneumatization surrounding TMJ structure in comparison to 2D images. Evaluation of TMJ components accurately before surgical intervention is crucial to prevent complication or increase the success of therapy.

Effect of Sphenoid Sinus Pneumatization on the Surgical Windows for Extended Endoscopic Endonasal Transsphenoidal Surgery

BACKGROUND

Little is known on the impact of the pattern and extent of pneumatization of the sphenoid sinus (SS) on the dimensions of the surgical windows used in extended endoscopic endonasal transsphenoidal approaches. We therefore investigated whether the distances between the 2 optic canals and between the paired paraclival carotid arteries are influenced by the pattern and extent of pneumatization of the SS.

METHODS

One hundred high-resolution computed tomography scans from 47 adult female and 53 adult male patients were analyzed. The pattern of SS pneumatization was classified into conchal, presellar, and sellar types. Sellar-type sinuses were then classified according to a newer detailed classification system. Maximal anteroposterior (AP), transverse (TR), and craniocaudal diameters of the SS, interoptic distance at the limbus sphenoidale (IODL) and at the entrance of the optic canal (IODE) and the intercarotid distance between the paraclival carotids (ICD) were measured. A 2-tailed Mann-Whitney U test and Pearson correlation coefficient (R) were used for statistical analysis. A P value <0.05 was considered statistically significant.

RESULTS

Positive correlation was found between IODL and both AP and TR diameters of the SS; between IODE and both AP and TR diameters of the SS; and between ICD and all diameters of the SS. The highest correlation for each of the IODL, IODE, and ICD was noted with the TR diameter of the SS.

CONCLUSIONS

During the development of the SS, pneumatization progress likely exerts quantitative and direction-specific forces, which gradually increase the interoptic and intercarotid distances.

Histomorphological study on hypocellularity in mastoid processes from archaeological human skeletons

OBJECTIVE

To evaluate processes causing two types of mastoid hypocellularity (Type 1 and Type 3), and to provide histomorphological criteria for a differential diagnosis in archaeological human bone.

MATERIALS AND METHODS

Eight human crania from the early medieval cemetery in Dirmstein (Rhineland-Palatinate, Germany) displaying secondary obliteration of mastoid air cells were analyzed using light-microscopy and backscattered electron imaging.

RESULTS

In Type 1 hypocellularity, obliteration starts in the non-pneumatized portion of the mastoid process and extends into the pneumatized portion. The findings could represent a chronic, maybe recurrent condition related to a pathologically altered middle ear mucosa in early childhood. In Type 3, a sequence of resorptive and proliferative processes are present and are consistent with a healing stage of mastoiditis.

CONCLUSIONS

Using histomorphology, in vivo processes resulting in different types of mastoid hypocellularity can be assessed, even in bones that have undergone some degree of diagenesis.

SIGNIFICANCE

The study provides methods to evaluate the etiology of histomorphological changes of the mastoid process, which potentially provides insight into the presence of infection and inflammation in past populations.

LIMITATIONS

Diagenetic modifications of archaeological bone can hinder assessment of histomorphological change, requiring careful evaluation during analysis.

SUGGESTIONS FOR FURTHER RESEARCH

Including histomorphology in future studies on archaeological human crania can contribute to an improved differential diagnosis of pathological conditions in the middle ear region.

Anatomical variation of the pneumatized superior turbinate and its impact on endoscopic sinus surgery in chronic rhinosinusitis

PURPOSE

The posterior ethmoid sinus is adjacent to important structures, such as the orbit, optic nerve, skull base, and ostium of the sphenoid sinus. The purpose of this study was to examine the effect of pneumatization of the superior turbinate (ST) and its basal lamella, and of the position of the anterior wall of the sphenoid sinus, on opening of the posterior ethmoid and sphenoid sinuses.

METHODS

On axial, coronal, and sagittal computed tomography images, 394 sinuses of 197 patients who underwent endoscopic sinus surgery at Toho University Omori Medical Center in Tokyo, Japan, were classified according to the presence or absence of pneumatization of the ST and its basal lamella. The basal lamella of the ST was classified separately into the vertical and horizontal portions. We examined whether the classification of the anterior wall of the sphenoid sinus was associated with the structure of the ST.

RESULTS

Pneumatization was observed in the ST in 28 sinuses (7.1%), in the vertical portion of the basal lamella in 127 (32.2%), and in the horizontal portion of the basal lamella in 90 (22.8%). Pneumatization in the horizontal portion of the basal lamella was significantly more common in the anterior sphenoidal wall classified as optic-canal type.

CONCLUSION

Consideration should be given to the pneumatization of the ST and its basal lamella and optic-canal-type anterior sphenoidal wall, because these reduce the volume of the posterior-most ethmoid cell and may increase the risk of damaging the skull base and optic nerve.

Anatomical Variations of the Nose and Paranasal Sinuses: A Computed Tomographic Study

To evaluate the anatomical variations in computed tomographic (CT) images of paranasal sinuses and to investigate association between them.

DESIGN

Retrospective study.

SETTING

Tertiary care center in the southern part of India.

SUBJECTS

Radiological images of paranasal sinuses belonging to chronic rhinosinusitis patients managed between June 2016 and November 2018.

METHODS

The studied characteristics in the CT images included the deviated nasal septum (DNS), concha bullosa (CB), Haller cell (HC), Onodi cell (OC), pneumatization of anterior clinoid process (ACP), pterygoid base (PB), superior turbinate, inferior turbinate, crista galli (CG), and nasal septum. The height of the lateral lamella of the cribriform plate, the sphenoid pneumatization pattern, and the optic nerve relationship with sphenoid sinus were studied separately. The associations between these factors, and with maxillary sinus opacifications were also investigated. A total of 151 adult patients' CT images were analyzed. The most common manifestations noted were DNS, CB and pneumatized PB, seen in 83.4%, 49% and 47% of the patients respectively. The rates of HC, OC, pneumatized septum, pneumatized CG, and pneumatized ACP were 39%, 23%, 27%, 43% and 27% in that order. Rates of most of these variations were within the range reported in the literature. Chi square test revealed that the OC was independently associated with pneumatized CG and pneumatized septum. The maxillary sinus opacification was related to DNS and CB, but not with protrusion of tooth root into the sinus. Most of the anatomical variations were comparable with the reports across the globe, however, the associations between these variations weren't common in our cohort.

Relationship between Anatomical Variations of Sinonasal Area and Maxillary Sinus Pneumatization

INTRODUCTION

Maxillary sinuses are among the largest paranasal sinuses with various shapes and volumes. The dimensions and volumes of maxillary sinuses play an important role in the surgical treatment plan. The higher levels of pneumatization of alveolar bone lead to the increase of odontogenic sinusitis which cause problems in dental implantation. Therefore, this study aimed to evaluate the relationship between maxillary sinus volume and pneumatization and anatomical factors.

MATERIALS AND METHODS

In this cross-sectional study, computed tomography (CT) images of the healthy maxillary sinuses of 199 adult patients were reviewed. Amira software was used for the measurement of sinus volume. Sinus pneumatization of the alveolar bone in coronal CT scan images in the posterior teeth areas was measured. Moreover, anatomical variations of the sinonasal region, such as nasal septal deviation, and size of the ostium were measured and recorded. The Kolmogorov-Smirnov test, the t-test, and the Pearson's and Spearman's correlation coefficients were applied for data analysis.

RESULTS

According to the obtained results, the mean value of the maxillary sinus volume and the alveolar bone pneumatization were 15.54 mm³ and 3.54 mm, respectively. The mean value of the maxillary sinus volume was statistically higher among males than females (P<0.001). The prevalence of nasal septal deviation, concha bullosa, and maxillary sinus septa were 14.6%, 14.6% and 6% respectively. There were no association between anatomical factors, including the nasal septal deviation, the size of the ostium, concha bullosa, and maxillary sinus septa and maxillary sinus volume and pneumatization. P-value less than 0.05 was statistically significant.

CONCLUSION

No correlation was observed between the anatomical variations of the sinonasal region and maxillary sinus volume and pneumatization.

Revisited maxillary sinus pneumatization narrative of observation in Al-Madinah Al-Munawwarah, Saudi Arabia: A retrospective cross-sectional study

Objectives

Maxillary sinus pneumatization (MSP), is linked worldwide to number of factors. MSP measurements and assessment alongside potential correlates in Al-Madinah Al-Munawwarah, Saudi Arabia (SA) awaits identification.

Materials and methods

A retrospective cross-sectional study was conducted at Taibah University Dental-College and Hospital, Al-Madinah Al-Munawwarah; SA. The analysis included 700 female patients digital Orthopantomogram (OPG), of which 535 (76%) OPGs were usable. MSP was established according to the distance between the maxillary sinus floor and posterior teeth apices number 15, 16, 17, 18, 25, 26, 27 and 28. MSP categorized as followed: Sever MSP (Category I), Moderate MSP (Category II) and No MSP/normal (Category III). Descriptive statistics, and inferential analysis were carried out.

Results

Mean age of the patients was 30.11 (±10.26) and 290 (54.5%) were Saudi nationals. Severe pneumatization (category I) was prominent in the right and left first and second molars, 16, 26, 17, 27 (66%, 64%, 63% and 62%, respectively). A statistically significant difference (P < 0.0005) was observed between pneumatization categories in all sites. Furthermore, the impact of young age on levels of MSP was statistically significant (P < 0.05) on most teeth. However, nationality was non-significantly (P > 0.05) associated with MSP levels.

Conclusion

High percentages of female patients showed bilateral sever MSP in the upper molar area, specifically, young age group.

Clinical significance

The oro-antral communication during extraction and surgical cases of female patients' maxillary teeth is possible. This should be considered during dentists' daily practice in this geographic area of SA.

Spontaneous Fractures in the Setting of Extensive Craniocervical Pneumatization: Case Report and Literature Review

BACKGROUND

Cranial pneumatization in humans is normally confined to the paranasal sinuses and the petrous and mastoid parts of the temporal bones.

CASE DESCRIPTION

We present a case of left-sided fractures of the occipital condyle and lateral mass of the atlas in the setting of extensive craniocervical pneumatization but in the absence of trauma, with a resulting unilateral hypoglossal nerve palsy.

CONCLUSIONS

We discussed the possible etiology of this rare disease, its management, and prognosis.

New case of concha bullosa from Bronze Age Iberia (Granada, Spain)

OBJECTIVE

This study aims to expand knowledge of Concha bullosa in a prehistoric population.

MATERIALS

The skull of an adult female from the Bronze Age archeological site ofCastellón Alto (Granada, Spain), dated between 1900 and 1600 BCE.

METHODS

The diagnosis of middle turbinateconcha bullosa was based on macroscopic, radiographic, and computed tomography studies.

RESULTS

This is one of the oldest findings ofconcha bullosa in Europe. Despite the possible obstruction of the osteomeatal complex by the concha bullosa in this individual, no signs of sinusitis were observed in maxillary sinuses.

CONCLUSIONS

The maxillary sinuses of this female showed no signs of sinusitis related to theconcha bullosa.

SIGNIFICANCE

This study provides new evidence on the chronological limits of this condition. The particular funeral rites of these populations have preserved the majority of skeletons at this site in an excellent condition.

LIMITATIONS

The identification ofconcha bullosa continues to be rare in ancient populations, in part due to the poor preservation of nasal bones in archeological collections. Suggestions for further research: Detailed study of the nasal cavity of adequately preserved individuals can be expected to identify further cases of concha bullosa in ancient populations.

Prevalence of pneumatization of the articular eminence and glenoid fossa viewed on cone-beam computed tomography examinations in a Turkish sample

OBJECTIVE

The aim of this study is to evaluate the prevalence of the pneumatization of the articular eminence and glenoid fossa (PAT and PGF, respectively) using cone-beam computed tomography (CBCT).

METHODS

CBCT images of 1000 patients (511 females and 489 males) representing 2000 regions of interest (the glenoid fossa and articular eminence of each patient) were examined retrospectively with regard to age, gender, laterality, and type of pneumatization. The mean age of the female patients was 39.66 and that of males was 39.79. Suitable images from patients aged 16 years and over found in the archives of CBCT images were included in the study. The data were assessed using IBM SPSS 20 and statistical comparisons between two categorical variables were conducted using Chi square tests.

RESULTS

It was observed that 14.7% of the patients had PAT and 47.1% had PGF. There was no significant difference in PAT and PGF prevalence between ages, age ranges, and gender in our study (p > 0.5).

CONCLUSIONS

It is important to evaluate the pneumatic cells in the articular eminence and glenoid fossa regions before surgery. It was also found that CBCT is more helpful in detecting pneumatization than plain film.

Prevalence and characteristics of pneumatizations of the articular eminence and roof of the glenoid fossa on cone-beam computed tomography

OBJECTIVE

The aim of this study was to determine the prevalence and characteristics of pneumatization of the articular tubercle (PAT) and pneumatization of the roof of the glenoid fossa (PRGF) in a large population using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

This study was designed to evaluate the CBCT images of 1000 patients. The prevalences of the pneumatizations by age, sex, locularity, and laterality were determined. The significance of differences between variables was evaluated by the Chi-square test and analysis of variance.

RESULTS

PAT was detected in 28.4% of the zygomatic bone sides and PRGF in 29.6%. Bilateral PAT was detected in 176 (17.6%) patients and bilateral PRGF in 195 (19.5%). The mean age of patients with PAT was 47.33 years and that of patients with PRGF was 45.62 years. Multilocular appearance was observed significantly more often than unilocular type for both pneumatizations (p < 0.01). Unilateral PAT cases were slightly, but significantly, higher than bilateral PAT cases (p = 0.047), while no significant difference was observed between unilateral and bilateral PRGF cases.

CONCLUSIONS

In conclusion, PAT and PRGF can be assessed more accurately on CBCT images than on plain radiographs. During routine radiological investigations, maxillofacial radiologists should be aware of zygomatic air cells.

The prevalence of pneumatized articular eminence in the temporal bone. Do we need a high resolution computed tomography-based novel risk classification for eminectomy?

INTRODUCTION

Besides mastoid air filled cells, pneumatizations (PN) occasionally occur in the articular eminence (AE) of the temporomandibular joint (TMJ). These findings represent no pathological character but may increase the risk of perforating the AE during eminectomy with potential harming the skull base. Various classifications catagorize the degree of temporal PN without focussing solely on the AE. Panoramic radiograph (PR) and computed tomographie (CT) are both described as suitable for diagnosing PNs. Are the common ways of imaging capable for precise diagnosis and do we need a risk pattern for eminectomy?

METHODS

A 4-year retrospective study evaluated high resolution computed tomographie (HRCTs) of 300 patients. We screened digitalized skull images for PN of the AE. The frankfort horizontal was determined as the reference mark for measurements. Images were assessed by a craniomaxillofacial surgeon and a radiologist.

RESULTS

300 patients (600 AEs) were investigated. We detected 60 PNs (10% of all AEs) in 44 patients (14.7%). We subdevided the findings according to the extent of PN. 10 AEs showed PNs of less than 20% (type 1); n=18: 21-40% (type 2); n=18: 41-70% (type 3). n=14: 71 to 100% (type 4). In 32 cases (72.7%) with 42 PNs a PR existed. Of the 42 AEs, corresponding PN could be detected in 21 cases (50%).

DISCUSSION

PNs are a potential threat when performing TMJ surgery. Sufficient preoperative imaging is required to avoid severe endangerment for the patient. CT imaging is most suitable detecting PNs. PR seem to fail in diagnosing PNs of different degree. Our novel HRCT-based classification shows the distribution of PNs and provides a risk pattern.

CONCLUSION

HRCT exceeds the diagnostic accuracy of PR in detecting pneumatized AEs. PR is not capable for detecting PNs of different degree. A novel classification may increase the prediction of perforation risk. Restricting eminectomy to reduce height only to a certain amount reduces the risk of complications.

Prevalence and Characteristics of Articular Eminence Pneumatization: A Cone-Beam Computed Tomographic Study

Purpose

The temporal bone represents a variety of pneumatization patterns with clinical significance for planning surgical procedures in this area. The purpose of the present study was to assess the prevalence and characteristics of the glenoid fossa and articular eminence pneumatization and to classify the pattern of pneumatization using CBCT images.

Methods

CBCT images of 327 patients (654 temporal bones) were evaluated to determine pneumatized articular eminence prevalence and characteristics. Gender, age, laterality, type and grade of pneumatization were recorded for the left and right sides. Chi-square test was used to evaluate the relationship between pneumatized articular tubercle and gender, grade and type.

Results

PAT was identified in 251 (76.7%) patients of whom 139 (55.4%) were male and 112 (44.6%) were female with a mean age of 30.31 ± 10.32 years. Bilateral PAT occurred in 175 (69.7%) patients. Three hundred and ninety-six (93%) of areas were multilacunar, and 30 (7%) were unilacunar. Of 654 areas, 228 (34.8%) had grade 0, 299 (45.7%), grade 1, 92 (14.1%), grade 2 and 35 (5.4%), grade 3. No statistically significant correlation was found between prevalence of pneumatization, gender, type and grade.

Conclusion

The present study emphasized the need to assess PAT before surgical intervention of TMJ. CBCT provides reliable and accurate information to determine the characteristics, the exact extension of pneumatization and its relationship to the adjacent structures. The preoperative temporal bone CBCT is a crucial component of the evaluation of PAT in patients candidate for surgical intervention of TMJ.

Coincidence of Concha Bullosa with Nasal Septal Deviation; Radiological Study

Introduction Concha bullosa (CB) is the most common sinonasal anatomical variation reported in literature, it occurs most often in the middle turbinate. Causes of development are not clearly identified but coincident prevalence with deviated nasal septum (DS) is common. Objective To study the relationship between DS and development of CB. Methods A prospective study including 40 patients with DS, CT scans were thoroughly analyzed to detect the presence of CB, its type, and laterality. Effect of degree of septal deviation from the midline and level of deviation in the axial plane were also addressed. Results The study included 40 patients with DS; 15 of them had associated CB; the lamellar type of CB was the most prevalent followed by the true type. Conclusion Incidence of CB was higher in patients with increased angle of septal deviation and with lower level of deviation in the axial plane.

Prevalence of temporal bone pneumatization in relation to temporomandibular joint - A computed tomographic study

BACKGROUND

Pneumatic spaces represent sites of minimal resistance, facilitating the spread of various pathological processes into the joint such as tumors, infection or fractures or vice versa. Considering the clinical importance of temporomandibular joint, prevalence of pneumatic spaces of the temporal bone in relation to TMJ in the roof of the TMJ fossa; articular eminence; zygomatic process and peritubal area was determined using Computed tomography. Laterality and gender wise prevalence of pneumatic spaces around the TMJ was also assessed.

MATERIALS AND METHODS

A total of 100 high-resolution CT images of adult patients subjected to CT scan for the base of skull/temporal bone were utilized. Axial, reformatted coronal and sagittal images were analyzed on a DICOM viewer for the presence and distribution of pneumatic spaces of the temporal bone around TMJ in the roof of TMJ fossa, articular eminence, zygomatic process and peritubal area.

RESULTS

The extent of pneumatization of the temporal bone varied considerably. The prevalence of pneumatization of the roof of the TMJ fossa was 52%, articular eminence (12%), the root of the zygomatic process (5%) and peritubal area was 56%. Higher frequency of bilateral pneumatization was seen. No statistically significant correlation was seen in gender wise distribution of pneumatization.

CONCLUSION

The present study revealed higher prevalence of pneumatization of temporal bone around TMJ. The knowledge of these air spaces is helpful for the interpretation of imaging studies and to understand the spread of pathological processes into the joint.

Evaluation of posterior clinoid process pneumatization by multidetector computed tomography

In the present study, we investigated the types and ratio of posterior clinoid process (PCP) pneumatization in paranasal sinus multidetector computed tomography (MDCT). Paranasal MDCT images of 541 subjects (227 males, 314 females), between 15 and 65 years old, were included into the study. Pneumatization of anterior clinoid process and pneumatization types (I, II, or III) were evaluated in the males and females. PCP pneumatization was detected in 20.7 % of the males and 11.5 % of the females. Right, left, and bilateral PCP pneumatizations were detected in 7.9, 5.7, and 7.0 % of the males and 2.9, 3.2, and 4.5 % of the females, respectively. PCP pneumatization of the males is significantly higher than the females. The most detected type of pneumatization was type I (61.2 %) for all groups. In right, left, and bilateral pneumatizations separately, type I pneumatization was the most detected pneumatization type with the ratio of the 70.4, 65.2, and 50.0 %, respectively. In males, type I (61.7 %), and similarly in females, type I (60.6 %) pneumatization were detected more. Type II and type III pneumatizations were detected in decreasing order in both groups. In younger subjects, pneumatization of posterior clinoid process was found as higher, and in older subjects, PCP pneumatization was found as lower. Sclerosis process related to the aging may be responsible for the lower pneumatization ratios in older subjects. Structure of the surrounding regions of PCP is important for surgical procedures related to cavernous sinus, basilar apex aneurysms, and mass lesions. Preoperative radiological examinations are useful for operative planning. Any anomalies to PCP can cause unnecessary injury to the neurovascular complex structure around the cavernous sinus or postclinoidectomy CSF fistulas. Posterior clinoidectomies should be avoided in patients with type III PCP pneumatization to prevent CSF fistulas.

Pneumatization within a maxillary sinus graft: a case report

Rehabilitation of edentulous posterior maxilla with implant-supported prostheses frequently presents a challenge to dentists. This is due to insufficient bone within the region, in addition to other limiting factors such as anatomical pneumatization of the maxillary sinus. Thus, grafting of the maxillary sinus is a common procedure used to counteract these problems. Regardless of the type of biomaterial used, the success of the procedure is dependent on the formation of high-quality bone. Therefore, vascularization is a key factor for successful grafting and for the long-term maintenance of the treatment. This paper reports a clinical case of bone graft pneumatization and attempts to elucidate its potential etiology.

Is there a relationship between sphenoid sinus types, septation and symmetry; and septal deviation?

In the present study, we investigated whether there is a relationship between sphenoid sinus (SS) types, septation (lobulation) and symmetry; and septal deviation (SD) by multidetector computed tomography (MDCT). Paranasal MDCT images of 202 subjects (131 males, 71 females), between 10- and 88-year-old, were included into the study. SS type (conchal, presellar or sellar), SS symmetry, SS septation (lobulation) and SD were evaluated by MDCT images. In the present study, in both males (83.2 %) and females (85.9 %); and in all age groups (80.4-85.7 %), sellar type sphenoid sinus were more detected. Conchal type was detected in two cases of the males (1.5 %) and none of the females. SS was detected mainly as multi-septated (multi-lobulated) (51.9 % in males and 56.3 % in females; in all age groups as 51.0-56.8 %; and both SD (+) and SD (-) groups as 51.2-56.8 %). In subjects with SD, asymmetric SS was detected in 80.2 %. Whereas in SD (-) subjects, asymmetric SS was detected in 50.6 %. Sellar type SS pneumatization is the most detected type in our cases. Presence of SD was related to the higher SS asymmetry values. In SD (-) subjects, SS was detected as symmetric. Nasal septal deformities such as SD may influence the development of the SS pneumatization and asymmetric septation. For well anatomic orientation of the surgeons, good anatomy knowledge and preoperative detailed examination of the CT scans are very important.

Evaluation of Anatomic Variations in Maxillary Sinus with the Aid of Cone Beam Computed Tomography (CBCT) in a Population in South of Iran

STATEMENT OF THE PROBLEM

Anatomic variations of the maxillary sinus can be detected in cone-beam computed tomography (CBCT) and may assist to locate the posterior superior alveolar artery (PSAA) and define the maxillary sinus morphology more accurately for a more strict surgical treatment plan.

PURPOSE

The study aimed to determine normal variations of the maxillary sinus with the aid of CBCT in a sample population in south of Iran.

MATERIALS AND METHOD

This cross-sectional prevalence study was based on evaluation of 198 projection data of CBCT scans of some Iranian patients aged 18-45 who referred to a private oral and maxillofacial radiology center in Shiraz from 2011 to 2013. CBCT scans were taken and analyzed with NewTom VGi device and software. The anatomic variations which were evaluated in the axial images included the presence of alveolar pneumatization, anterior pneumatization, exostosis, and hypoplasia. Moreover the location and height of sinus septa, and the location of PSAA were assessed. SPSS software (version 17.0) was used to analyze the data.

RESULTS

In a total of 396 examined sinuses, maxillary sinus alveolar pneumatization was the most common anatomic variation detected. Anterior pneumatization was detected in 96 sinuses (24.2%). Antral septa were found in 180 sinuses (45.4%) and were mostly located in the anterior region. Meanwhile, PSAA was mostly detected intra-osseous in 242 sinuses (65.7%).

CONCLUSION

Anatomic variations of the maxillary sinus were common findings in CBCT of the maxilla. Preoperative imaging with CBCT seems to be very helpful for assessing the location of PSAA and the maxillary sinus morphology, which may be used to adjust the surgical treatment plan to yield more successful treatments.

Normal Variations of Sphenoid Sinus and the Adjacent Structures Detected in Cone Beam Computed Tomography

STATEMENT OF THE PROBLEM

The sphenoid sinus is a common target of paranasal surgery. Functional endoscopic sinus surgery is likely to endanger the anatomic variations of vital structures adjacent to the sphenoid sinus.

PURPOSE

The aim of this study was to determine the variations of sphenoid sinus and the related structures by using cone-beam computed tomography (CBCT).

MATERIALS AND METHOD

In this descriptive-analytic study, CBCT images of 103 patients aged above 20-years were selected (206 sides). Degree of pneumatization of sphenoid sinus, pneumatization of the anterior clinoid process, pterygoid process, protrusion of optic canal, vidian canal, and foramen rotundum, as well as prevalence of sinus septa were recorded. Examinations were performed using On-Demand software (Version 1); data were analyzed by using chi-square test.

RESULTS

There was a statistically significant correlation between the pterygoid pneumatization and vidian canal protrusion (p< 0.001), and foramen rotundum protrusion (p< 0.001). The optic canal protrusion was found to be significantly associated with the anterior clinoid pneumatization and pterygoid process (p< 0.001). Statistically significant relationship was also observed between the carotid canal protrusion and pterygoid process pneumatization (p< 0.001).

CONCLUSION

The anatomical variations of the sphenoid sinus tend to give rise to a complexity of symptoms and potentially serious complications. This variability necessitates a comprehensive understanding of the regional sphenoid sinus anatomy by a detailed CBCT sinus examination.

ZACD: A Retrograde Panoramic Analysis among Indian Population with New System of Classification

INTRODUCTION

Zygomatic Air Cell Defect (ZACD) has been considered as a normal radiographic variant with a spare knowledge. This should be judged before any surgical procedure of the temporal region as lack of which can lead to infections of cranium and may other complications.

AIM

The present study was undertaken to estimate the prevalence and characteristics of ZACD and to propose a classification for the same using digital panoramic radiography.

MATERIALS AND METHODS

A total of 6825 digital panoramic radiographs were evaluated retrospectively of subjects aged between 4-90 years from both genders. The radiographs were evaluated by 4 (four) oral radiologists and the ZACD was recorded only when the decision was indisputable.

RESULTS

Out of 6825 digital panoramic radiographs evaluated ZACD was noticed in 133 subjects with an overall prevalence of 1.94%. A male predilection was noted in the present study with the maximum prevalence during the second, third and fourth decade of life and as the age increases its prevalence decreases. Most commonly it was found to be unilateral and the unilocular presentation being more common.

CONCLUSION

Most of the finding of the present study is in acceptance with those conducted previously, but some of the finding contradicts those in the previous ones. It can be because of low sample size of the previous studies. Moreover this study gives a new system to classify these defects to help diagnose the nature of the defect.

The classification of frontal sinus pneumatization patterns by CT-based volumetry

PURPOSE

We aimed to define the classification of frontal sinus pneumatization patterns according to three-dimensional volume measurements.

METHODS

Datasets of 148 sides of 74 dry skulls were generated by the computerized tomography-based volumetry to measure frontal sinus volumes. The cutoff points for frontal sinus hypoplasia and hyperplasia were tested by ROC curve analysis and the validity of the diagnostic points was measured.

RESULTS

The overall frequencies were 4.1, 14.2, 37.2 and 44.5 % for frontal sinus aplasia, hypoplasia, medium size and hyperplasia, respectively. The aplasia was bilateral in all three skulls. Hypoplasia was seen 76 % at the right side and hyperplasia was seen 56 % at the left side. The cutoff points for diagnosing frontal sinus hypoplasia and hyperplasia were '1131.25 mm(3)' (95.2 % sensitivity and 100 % specificity) and '3328.50 mm(3)' (88 % sensitivity and 86 % specificity), respectively.

CONCLUSIONS

The findings provided in the present study, which define frontal sinus pneumatization patterns by CT-based volumetry, proved that two opposite sides of the frontal sinuses are asymmetric and three-dimensional classification should be developed by CT-based volumetry, because two-dimensional evaluations lack depth measurement.

Prevalence of Zygomatic Air Cell Defect using Orthopantomogram

AIM

To determine the prevalence, radiographic appearance, variations, characteristics and establishing dominant location and type of zygomatic air cell defect (ZACD) among the North Indian population.

MATERIALS AND METHODS

The panoramic radiographs of 2500 dental clinic outpatients were examined for the presence of ZACD for estimating the prevalence and characteristics of the ZACD.

RESULTS

ZACD was found in 63 patients with a prevalence of 2.5% with male predominance. Unilateral (70%) and unilocular appearance (78%) of ZACD were the dominant patterns. Patients with ZACD had a mean age of 37.4 years and a range of 19-78 years.

CONCLUSION

The prevalence of ZACD among the Indian population is in accordance with the other studies carried out in other populations of the world. So it is important for surgeons to assess location of ZACD before planning any surgical procedure in order to avoid intraoperative complications.

Pneumatization Pattern in Squamousal Type of Chronic Otitis Media

To study the pneumatization pattern of mastoid bone in cases of squamousal type of chronic otits media and analyze pneumatization pattern of opposite normal ear in cases of unilateral chronic otitis media (COM). A total of 94 patients (104 ears) between the age group of 7-84 years attending the E.N.T outpatients, inpatients and casualty of Acharya Vinoba Bhave Rural Hospital, Sawangi (Maghe), Wardha, after applying inclusion and exclusion criteria were found suitable and hence selected for the present study and were subjected to bilateral X-ray mastoid (Schuller's view). HRCT temporal bone done in selected 55 patients. On analyzing patients radiologically (X-ray mastoid), it was found that out 104 ears, mastoid was pneumatized in 2 (1.92 %) diploic in 20 (19.23 %) and sclerotic in 82 (78.85 %) ears. Contralateral mastoid of 70 normal ears, mastoid was pneumatized in 30 (42.86 %) diploic in 22 (31.43 %) and sclerotic in 18 (25.71 %) ears. Most of the diseased ear demonstrated non pneumatized mastoid (98.08 %) whereas contra lateral mastoid of 70 normal ear, showed significantly more pneumatization This difference is statistically significant (P value < 0.0001). Significantly more sclerosis and non pneumatization in the ear with COM of squamousal type than the healthy contralateral ear supports the environmental theory.

Sphenoid sinus types, dimensions and relationship with surrounding structures

The human sphenoid sinus is an extremely variable cavity and an important landmark in hypophyseal surgery. The aim of this study was to investigate the relationship between the sphenoid sinus type, size, extent of pneumatization and occurrence of protrusions of the adjacent neurovascular structures. A total of 51 randomly selected skulls (≥20 years of age, 33 male; 102 sinuses) were analyzed using cone beam computed tomography to estimate pneumatization extension beyond the body of the sphenoid (planum sphenoidale, pterygoid process, greater wings, clivus, dorsum sellae) and protrusions of the maxillary, mandibular, optic or pterygoid nerve or the internal carotid artery. Difference in pneumatization type between the left and the right-sided sinus was observed in 45% of the skulls. Conchal pneumatization was registered in 2%, presellar in 24%, sellar in 41% and postsellar in 33% of total sinuses. Presellar sinuses frequently pneumatized planum sphenoidale and sporadically other structures, and were characterized by sporadic optic nerve protrusions. Sellar and particularly postsellar sinuses were characterized by simultaneous pneumatization extensions and neurovascular protrusions. In the case of postsellar-type sinuses, the probability of these multiple interactions was not affected by their actual size, while it increased with the increasing sinus dimensions in the case of sellar-type sinuses. A more detailed analysis indicated that increasing sinus height, length or width increased the probability of interactions and pneumatization of particular surrounding structures. Data suggest that the sphenoid sinus pneumatization type and dimensions might be used to estimate the risks of iatrogenic injury during transsphenoidal surgical procedures.

Arrested pneumatization of the sphenoid sinus mimicking intraosseous lesions of the skull base

Arrested pneumatization of the sphenoid sinus is a developmental variant that is not always well recognized and is often confused with other pathologies associated with the skull base. This report describes the case of a patient referred for cone-beam computed tomography (CBCT) imaging for dental implant therapy. CBCT demonstrated a well-defined incidental lesion in the left sphenoid sinus with soft tissue-like density and sclerotic borders with internal curvilinear opacifications. The differential diagnoses included intraosseous lipoma, arrested pneumatization of the sphenoid sinus, chondrosarcoma, chondroid chordoma, and ossifying fibroma. The radiographic diagnosis of arrested pneumatization was based on the location of the lesion, its well-defined nature, the presence of internal opacifications, and lack of expansion. Gray-scale CBCT imaging of the area demonstrated values similar to fatty tissue. This case highlighted the fact that benign developmental variants associated with the skull base share similar radiographic features with more serious pathological entities.

Any Correlation?

The aim of this study is to assess the pneumatization of the paranasal sinuses (PNS) and other parts of temporal bone such as mastoid air cells and to investigate if there was any association between the aeration of these structures among the three major ethnic groups in Malaysia (Malay, Chinese, Indian) as this would be representative of Asia. A retrospective review of 150 computed tomography (CT) scans of PNS and temporal bones was done and analysed. The pneumatization of each area was obtained and compared using statistical analysis. Patients with a history of previous medical or surgical problems in the intended areas were excluded from the study. The pneumatization of the mastoid air cells and other temporal bone parts were noted to be symmetrical in more than 75 %. There was a positive correlation between the pneumatization of mastoid air cells and that of the sphenoid sinus. The prevalence of Agger nasi, Haller's and Onodi cells was observed to be significantly higher in the Chinese group. Preoperative assessment of the temporal bone and PNS with CT scan may be helpful in the evaluation of their anatomical landmark and decrease the possibility of surgical complications related to 3D structures.

Three-dimensional linear and volumetric analysis of maxillary sinus pneumatization

Considering the anatomical variability related to the maxillary sinus, its intimate relation to the maxillary posterior teeth and because of all the implications that pneumatization may possess, three-dimensional assessment of maxillary sinus pneumatization is of most usefulness. The aim of this study is to analyze the maxillary sinus dimensions both linearly and volumetrically using cone beam computed tomography (CBCT) to assess the maxillary sinus pneumatization. Retrospective analysis of 30 maxillary sinuses belonging to 15 patients’ CBCT scans was performed. Linear and volumetric measurements were conducted and statistically analyzed. The maximum craniocaudal extension of the maxillary sinus was located around the 2nd molar in 93% of the sinuses, while the maximum mediolateral and antroposterior extensions of the maxillary sinus were located at the level of root of zygomatic complex in 90% of sinuses. There was a high correlation between the linear measurements of the right and left sides, where the antroposterior extension of the sinus at level of the nasal floor had the largest correlation (0.89). There was also a high correlation between the Simplant and geometric derived maxillary sinus volumes for both right and left sides (0.98 and 0.96, respectively). The relations of the sinus floor can be accurately assessed on the different orthogonal images obtained through 3D CBCT scan. The geometric method offered a much cheaper, easier, and less sophisticated substitute; therefore, with the availability of software, 3D volumetric measurements are more facilitated.

All concha bullosa: an undefined abnormality of the lateral nasal wall

Pneumatization of the turbinates, are the anatomic variations of lateral nasal wall. Turbinate pneumatization, refers to the existence of air cell inside the turbinates. Pneumatization of the middle turbinate is common, whereas rare in the superior and especially inferior turbinate. In this report we presented a case who has bilaterally pneumatization of all conchas.

Anterior pneumatization of the maxillary sinus - Presenting as a facial swelling

Over pneumatization of the paranasal sinuses is a fairly common finding on computerized tomography; but involvement of a small segment of the maxillary sinus especially the anteromedial aspect is very rare. We report a case of a twenty year old male who presented with a facial swelling. On CT scan, the swelling was found to be due to pneumatization of the anterior part of the maxillary sinus. Surgical treatment was carried out for cosmetic reasons.

Mastoid pneumatization and otosderosis-is there a correlation

The environment versus the genetic influence on the size of the mastoid pneumatization has been debated for years. A concrete evidence of the influence of environmental factors (e.g. inflammation) or heredity on pneumatization is still lacking. In this study the extent to mastoid peumatization in thirty otosclerotic ears was compared with control ears. The size of mastoid pneumatization was measured by the use of Law lateral x-ray projection with the help of planimetry. It was found that the average pneumatized area in otosclerotic ears was 14.73+ -3.55 cm2 compared to 10.60+3.62 cm2 in control ears which was statistically significant. In addition the mean area of mastoid air system was found to be more in the operated ears compared to the contralateral ears, the difference being statistically significant. However there was no correlation of mastoid pneumatization with degree and duration of hearing loss and type of otosclerotic focus. Our findings therefore show a link between otosclerosis and highly pneumatized mastoids thus indicating a likelihood of heredity playing a role in determining final type ot pneumatization.