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ORIGINAL ARTICLE
Year : 2018  |  Volume : 6  |  Issue : 1  |  Page : 3-8

The evaluation of the prevalence and localizations and of antral septa in people living in and around Diyarbakir using cone beam computed tomography


1 Department of Periodontology, Faculty of Dentistry, Harran University, Şanlıurfa, Diyarbakır, Turkey
2 Department of Periodontology, Faculty of Dentistry, Dicle University, Diyarbakır, Turkey

Date of Web Publication26-Apr-2018

Correspondence Address:
Devrim Deniz Uner
Faculty of Dentistry, Harran University, 63100 Şanlıurfa
Turkey
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jomr.jomr_37_17

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  Abstract 


Background: Anatomic variations of the maxillary sinuses affect the success of maxillary sinus operations. The aim of this study is to evaluate the prevalence and localizations of antral septa in patients living in and around Diyarbakır/Turkey using cone beam computed tomography (CBCT) images of the maxillary sinuses of these patients. Materials and Methods: This study was conducted using 692 CBCT reports obtained from patients. The antral septa identified on CBCT were separated into three regions based on their localizations. The region from the mesial to the distal of the 2nd premolar tooth was defined as the anterior region, the region from the distal of the 2nd premolar tooth to the distal of the 2nd molar tooth was defined as the medial region, and the region after the distal of the 2nd molar tooth was defined as the posterior region. Results: A total of 148 antral septa were observed in a total of 119 patients. Based on the number of patients, antral septa were detected in approximately 22% of the patients. The maxillary sinuses, in which antral septa were observed constituted 13.7% of the total examined healthy sinus. Of the detected antral septa, 17 were in the anterior region, 26 were in the posterior region, and 105 were in the medial region. Statistical analysis revealed that there was no statistically significant difference between the prevalence and localization of the antral septa in the left and right maxillary sinuses. Conclusions: The results obtained in our study indicate that the prevalence of antral septa is high that antral septa can be found in approximately one out of five people living in our region. For this reason, the anatomy of the region should be evaluated extensively with imaging.

Keywords: Antral septa, cone beam computed tomography, maxillary sinus


How to cite this article:
Uner DD, Izol BS, Ipek F. The evaluation of the prevalence and localizations and of antral septa in people living in and around Diyarbakir using cone beam computed tomography. J Oral Maxillofac Radiol 2018;6:3-8

How to cite this URL:
Uner DD, Izol BS, Ipek F. The evaluation of the prevalence and localizations and of antral septa in people living in and around Diyarbakir using cone beam computed tomography. J Oral Maxillofac Radiol [serial online] 2018 [cited 2018 Sep 21];6:3-8. Available from: http://www.joomr.org/text.asp?2018/6/1/3/231361




  Introduction Top


With each passing day, the use of implant-supported restorations for cosmetic and functional rehabilitation in the oral regions is becoming widespread. With tooth loss, the alveolar part of the posterior maxilla atrophies by being resorbed.[1] This results in vertical bone loss and sinus pneumatization. While the amount of these changes varies from person to person, this resorption due to atrophy causes a bone height that is unsuitable to form a basis for dental implants. In such cases, augmentation should be done by lifting the sinus floor before placing the dental implant.[2] In 1970, Tatum and also Boyne and James developed the maxillary sinus augmentation technique.[3],[4] This method is accepted as the most reliable method for maxillary sinus augmentation. The sinus augmentation method has been improved over time and become more easily applied method.[5] Although today, sinus floor elevation is considered a safe method, serious complications arise as a result of incorrect surgical planning and aggressive surgical maneuvers.[6] Perforation of the sinus mucosa can cause loss of the graft into sinus, graft infection, early failure of sinus lift, and sinusitis.[7] The perforation of the sinus membrane, usually occurring with a range of incidents and occurred between 7% and 35% of cases.[8],[9] The presence of an antral septum increases the risk of perforation of the sinus membrane during sinus floor elevation.[10],[11]

Bone protrusions in the maxillary sinus are called antral septa [Figure 1]. Since the detailed anatomy of the maxillary sinus was defined by Underwood in 1910, these bony protrusions are also called Underwood's septa. Some researchers have put forward hypotheses about the etiology of antral septa. Underwood stated that the septa rise up from in between two adjacent teeth and are seen in three specific areas (front, middle, and back) on the sinus floor.[11] Neivert said that the septa consisted of finger-shaped protrusions forming from the embryological sac of the ethmoid infundibulum.[12] In addition, Krennmair et al. named antral septa which form during the development of the maxilla as primary antral septa and those which form as a result of tooth loss as secondary antral septa.[13]
Figure 1: The aspect of antral septa at cone beam computed tomography

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Anatomic variations of the maxillary sinuses affect the success of operations (such as maxillary sinus endoscopy and sinus floor elevation) to be performed and increase the risk of complications.[3] Underwood's septa cause the membrane to become thin in the area, in which they are found and cause the membrane to be perforated during sinus floor elevation.[14] In addition, antral septa make procedures such as the passage of the sinus wall and elevation of the sinus membrane during sinus augmentation quite complicated.[15] The aim of this retrospective study is to use the cone beam computed tomography (CBCT) images of the maxillary sinuses of people living in Diyarbakır and the surrounding region to assess the prevalence and localization of antral septa in these patients.


  Materials and Methods Top


This study was carried out in accordance with the 1964 Declaration of Helsinki criteria. This study was approved by the Ethics Committee of the Dicle University Faculty of Dentistry with the protocol number 2015/12.

This study was conducted using 692 CBCT reports obtained from patients who were admitted to the Oral Diagnosis and Radiology, Oral and Maxillofacial Surgery, Periodontology, Orthodontics, Prosthetic Dentistry, Pedodontics, Dental Diseases, and Endodontics clinics at the Dicle University Faculty of Dentistry for any reason between October 2012 and February 2015. The reports of all patients were obtained using the three-dimensional CBCT device used at the hospital of our university (I-CAT ®, Model 17–19, Irma Medicine Sciences International, Hatfield, PA, USA). All obtained tomography reports were examined by Periodontology using the ICAT-vision imaging software and the Osirix imaging software (The OsiriX Foundation, Geneva, Switzerland, http://www.osirix-viewer.com). The Osirix imaging software was used to measure the distance between two points, while the ICAT-vision imaging software was used to measure the length of the antral septa on three-dimensional images. Measurements with the Osirix software were made using sagittal sections. When making measurements, an imaginary line was drawn on the part of the antral septum being displayed that was nearest to the base, after which the distance between this line and the most coronal part of the antral septum was measured, and this distance was recorded as the length of the antral septum. Of the septa that were displayed, those whose lengths were <2 mm were excluded from the study. In the radiographical examination done on 0.5 mm thick axial sections and 1 mm thick coronal sections, maxillary sinuses which gave off radiolucent images because they were filled with air and had completely clean borders were considered as healthy. Patients with pathological conditions such as focal mucosal thickening in the maxillary sinus, diffuse mucosal thickening, air-fluid level, and mucus retention cysts were considered unhealthy and were excluded from the study. Because a pathological condition was detected in the maxillary sinus of 158 patients on tomography, these patients were excluded from the study. The antral septa identified on CBCT were separated into three regions based on their localizations. The region from the mesial to the distal of the 2nd premolar tooth was defined as the anterior region, the region from the distal of the 2nd premolar tooth to the distal of the 2nd molar tooth was defined as the medial region, and the region after the distal of the 2nd molar tooth was defined as the posterior region. The data obtained were transferred to the Microsoft Excel software.

Statistical evaluation

In this study, descriptive statistics are given as mean, and standard error values are given for standard deviation and averages. The conformity of the data with the normal distribution assumption was tested with the Kolmogorov–Smirnov test, and their homogeneity was tested with Levene's test. The one-way ANOVA, independent Student's t- test, and correlation analysis tests were used in the comparison of averages between the groups for independent groups. A 95% confidence interval was used in all statistical analysis tests, and results were considered statistically significant for P < 0.05.


  Results Top


In the study that included 539 individuals, with 279 females and 260 males, 51.8% of the patients were female, and 48.2% were male. The youngest of the patients included in the study was 6, and the oldest was 84. The overall average age of the patients was calculated as 35.95 ± 18.10. The age of female patients ranged from 6 to 84 years. The average age of the female patients was calculated as 34.88 ± 18.35. The youngest of the males included in the study was 6, and the oldest was 74. The average age of males was calculated as 37.12 ± 17.8. Our study was conducted using the CBCT reports of 539 patients whose maxillary sinuses were considered as healthy. As a result of the analysis done, 148 antral septa were observed in a total of 119 patients. Based on the number of patients, antral septa were detected in approximately 22% of the patients. The prevalence of antral septa based on sinus in this and previous studies were shown in [Table 1].[16],[17],[18],[19] Among the 539 patients, 21 patients had antral septa in both maxillary sinuses, and four patients had two separate antral septa in one maxillary sinus. There were no patients with >2 antral septa in one maxillary sinus. Of the detected antral septa, 17 were in the anterior region, 26 were in the posterior region, and 105 were in the medial region. The right and left maxillary sinuses were also evaluated for the incidence of antral septa. In this comparison, nine of the antral septa observed in the anterior region were in the left maxillary sinus while 8 of them were in the right maxillary sinus, 40 of the antral septa observed in the medial region were in the left maxillary sinus while 65 of them were in the right maxillary sinus, and 15 of the antral septa observed in the posterior region were in the left maxillary sinus while 11 of them were in the right maxillary sinus area [Chart 1]. Statistical analysis revealed that there was no statistically significant difference between the prevalence and localization of the antral septa in the left and right maxillary sinuses.
Table 1: Percentage of sinuses with antral septa

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  Discussion Top


The maxillary sinuses are the largest of the paranasal sinuses in the skull. The base of the maxillary sinus which is in pyramid form is formed by the side wall of the nose, and the top is formed by the zygomatic protrusion. The upper part of the pyramid is formed by the base of the eye and the lower part of the alveolar part of the maxilla. In the literature, it is reported that the maxillary sinus extends from the molar teeth to the premolar teeth, but in only one case presentation, the anterior wall of the maxillary sinus has been shown to extend to the lateral incisor.[20] In the CBCT images that we examined, the anterior wall of the maxillary sinus ended at the alignment of the premolar teeth although in some patients it extended to the canines. However, the anterior wall of the maxillary sinus did not extend up to and beyond the lateral incisor tooth in any of the 539 patients.

The most common complication during maxillary sinus floor elevation is membrane perforation at a rate of 12%–44%.[21] Direct contact between the graft material and the sinus cavity during operation due to the perforation of the membrane can result in infection, chronic sinusitis, and graft and implant loss.[22] Factors that can cause membrane perforation include membrane thinness, the presence of a septum in the sinus, sharp and protruding bone structure, and physician's errors during osteotomy or membrane elevation.[23] The anatomic variations and anatomy of the maxillary sinus should be well known by the surgeon who will be making a surgical intervention here. To avoid complications, the morphology of the patient needs to be analyzed very well. Since septa found in the maxillary sinus are very important regarding the risk of membrane perforation, several studies have been conducted to determine their prevalence.[16] These studies on the anatomic structure of maxillary sinuses have mostly investigated anatomic variations such as the prevalence of antral septa.[1] These studies were performed on cadavers, during operations where the sinus floor was elevated, or radiologically using panoramic radiography or CT.[17] CT is the preferred method for determining the presence of antral septa because of the high-resolution imaging of bone structures. Panoramic radiography can also detect the presence of antral septa. However, studies done in comparison with CT have shown that panoramic radiography can give false results. In panoramic radiography, the maxillary sinus is cut by many radiopaque lines which form due to various superpositions. These lines are thought to have an effect on the misinterpretation of images.[16] For this reason, we conducted this study based on CBCT data.

Some of the studies conducted to investigate the prevalence of antral septa were carried out based on the number of sinuses, and some were carried out based on the number of patients.[16] The prevalence of antral septa ranges between 13% and 36% among populations.[11] In another study, it is reported that the prevalence of antral septa ranges between 13% and35.3% in studies based on the number of maxillary sinuses and between 21.6% and 66.7% in studies based on the number of patients.[24] In a study they conducted based on the number of sinuses, Underwood detected 30 antral septa in a total of 90 maxillary sinuses and reported the prevalence as 33%.[11] In a study they conducted, Krennmair et al. evaluated the prevalence of antral septa during sinus augmentation. In this study, the prevalence of antral septa was determined as 27.7%, whereas in another study carried out on cadavers they found the prevalence of antral septa as 36.6%.[13],[16] In studies conducted on cadavers, Underwood reported the prevalence of antral septa as 33.0%.[11] Çakur et al. reported the incidence of antral septa as 25.7% in a study they conducted using the CBCT images of 74 patients.[18] With evaluations made on CT images that have not been processed by a computer, Krennmair et al. reported the prevalence of antral septa as 16%.[13] Tadinada et al., also determined the prevalence of antral septa as 59.7% as a result of the study they carried out based on CT images.[19] In studies conducted by reformatting of CT, Velásquez-Plata et al., report an antral septa prevalence of 24%.[25] Kim et al. found the prevalence of antral septa as 26.5% in a study conducted in the same way.[1] Özeç et al. reported the antral septa prevalence in 18% and 13.7% of the maxillary sinuses on panoramic radiography and CBCT images, respectively.[17] Lee et al. compared number of the patient and maxillary sinus to evaluate the prevalence of antral septa in a study they conducted using CT images. In this study, they reported the prevalence of antral septa were present in 58 (24.6%) of the 236 maxillary sinuses and 55 (27%) of the 204 total patients.[26] Faramarzie et al. have found 39 antral septa in a total of 132 sinuses on CBCT and reported the prevalence of antral septa as 29.54%.[27] In our study, antral septa were detected in 119 (22%) of 539 patients when the number of patients was taken as a basis. This result, which emerged in our study, supported other studies. When the number of maxillary sinuses was taken as a basis, we found 148 (13.7%) antral septa in the 1078 maxillary sinuses examined in our study. Our study also found that the antral septa maxillary sinus ratio was similar to other studies [Table 1]. It is noteworthy that while 148 antral septa were observed in the study we conducted, the number of patients in whom these were observed was 119. This is because antral sinuses were observed bilaterally in some patients and some patients had more than one antral septum in one maxillary sinus. In an earlier study, antral septa were present bilaterally in 6.4% of the individuals, while 2.1% of the patients had more than one septa in a sinus.[17] In another study, the rate of bilateral antral septa was 5.45%, and the rate of multiple antral septa in one maxillary sinus was approximately 3.44%.[25] In our study, we determined the rate of bilateral antral septa as approximately 3.9% and the rate of multiple antral septa in one maxillary sinus as 0.74%. When previous studies are considered, the rates we found are lower. Pommer et al., in a meta-analysis in 2012 reported a low prevalence of antral septa (22.9%) among people living in Asia. They attributed this to the fact that the prevalence of antral septa varies among populations.[28]

Underwood attributed the different localizations of the antral septa within the maxillary sinus to the three different periods of tooth eruption. Underwood identified three different regions for the localization of antral septa. According to Underwood's definition, the anterior region is the region between the 2nd premolar and the 1st molar, the medial region is the region between the 1st and 2nd molar teeth, and the posterior region is the region distal to the 3rd molar tooth.[11] Velásquez-Plata et al. also identified three different regions for the localization of antral septa. In this definition, the anterior region is defined as the region between the mesial-distal of the 2nd premolar tooth, the medial region is defined as the region between the roots of the 2nd premolar and 2nd molar teeth, and the posterior region is the region distal to the root of the 2nd molar tooth.[25] In this study, we used Underwood's definition when determining the localization of antral septa.

As a result of examining the anatomic localization of antral septa, Valezquez-Plata determined that 24% of the septa were in the anterior region, 41% were in the medial region, and 35% were in the posterior region.[25] Kim et al. reported that 25.4% of antral septa were localized in the anterior region, 50.8% in the medial region, and 23.7% in the posterior region.[1] Lee et al. reported that 27.3% of antral septa were localized in the anterior region, 50% in the medial region, and 22.7% in the posterior region in the study they conducted using CT images.[26] Krennmair et al. reported the antral septa prevalence as 70% in the premolar region of the toothless maxilla and explained this high rate with seconder septa due to the molar and premolar teeth being lost at different times.[16] Orhan et al. reported the rate of septa occurring in the medial region as 6.1% in a study they conducted on the CBCT images of 272 patients in 2012.[29] Nearly 11.5% of the antral septa we detected were localized in the anterior region, 71% in the medial region, and 17.5% in the posterior region [Table 2]. The fact that a great portion of the antral septa we detected in our study were localized in the medial region supported other literature information. The number of antral septa we detected in the medial region was close to that found in other studies.
Table 2: Percentage of antral septa based on localization

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  Conclusions and Recommendations Top


The results obtained in our study indicate that the prevalence of antral septa is high that antral septa can be found in approximately one out of five people living in our region, and that the septa are located mostly in the medial region. For this reason, the anatomy of the region should be evaluated extensively with an imaging method such as CBCT before a delicate operation with serious complications such as maxillary sinus augmentation to be conducted, especially to the medial region.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

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Kim MJ, Jung UW, Kim CS, Kim KD, Choi SH, Kim CK, et al. Maxillary sinus septa: Prevalence, height, location, and morphology. A reformatted computed tomography scan analysis. J Periodontol 2006;77:903-8.  Back to cited text no. 1
    
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Cho SC, Wallace SS, Froum SJ, Tarnow DP. Influence of anatomy on schneiderian membrane perforations during sinus elevation surgery: Three-dimensional analysis. Pract Proced Aesthet Dent 2001;13:160-3.  Back to cited text no. 14
    
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Tadinada A, Jalali E, Al-Salman W, Jambhekar S, Katechia B, Almas K, et al. Prevalence of bony septa, antral pathology, and dimensions of the maxillary sinus from a sinus augmentation perspective: A retrospective cone-beam computed tomography study. Imaging Sci Dent 2016;46:109-15.  Back to cited text no. 19
    
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