Visibility, location, and morphology of the primary maxillary sinus ostium and presence of accessory ostia: a retrospective analysis using cone beam computed tomography (CBCT)



This retrospective study evaluated the visibility, location, and morphology of the primary maxillary ostium (PMO), as well as the presence and number of accessory maxillary ostia (AMO) in the maxillary sinus using cone beam computed tomography (CBCT).

Materials and methods

CBCT scans with a large field of view with both maxillary sinuses entirely visible, acquired from February 2016 to February 2018, were initially screened. Patients were included if there was no history of surgical intervention/trauma in the sinus region. Two observers evaluated the CBCTs for PMO and AMOs independently. PMO and AMOs were evaluated in axial, coronal, and sagittal CBCT views. In case of disagreement, a third observer served as a referee. The findings were correlated with age, gender, condition of the sinus mucosa, and status of the dentition to assess for potential influencing factors.


A total of 184 patients (368 maxillary sinuses) were included. PMO was present and patent in 346 (94.0%) of the 368 analyzed sinuses. Most of the PMOs were located above the attachment of and in the middle third of the inferior turbinate (76.1%) and exhibited a slit shape (71.1%). An AMO was present in 167 (45.5%) of the 368 analyzed sinuses, and 66 (17.9%) sinuses had multiple AMOs. Gender and sinus mucosa morphology were found to be influencing factors for the patency of the PMO. Furthermore, gender seems to be influencing the presence of an AMO.


Most of the analyzed maxillary sinus cavities in the present population had a patent PMO. Being male and having morphological changes of the sinus mucosa were factors associated with a reduced prevalence of a patent PMO.

Clinical relevance

A maxillary sinus with pathological findings of the mucosa seems to have a reduced prevalence of patent PMOs. Therefore, clinicians should take care to assess any clinical and radiographical sign indicating a potential maxillary sinusitis prior to surgical interventions in this region, especially in cases with planned sinus floor elevation.

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  1. 1.

    Wallace SS, Tarnow DP, Froum SJ, Cho S-C, Zadeh HH, Stoupel J, Del Fabbro M, Testori T (2012) Maxillary sinus elevation by lateral window approach: evolution of technology and technique. J Evid Based Dent Pract 12:161–171

    Article  Google Scholar 

  2. 2.

    Hauman C, Chandler N, Tong D (2002) Endodontic implications of the maxillary sinus: a review. Int Endod J 35:127–141

    Article  Google Scholar 

  3. 3.

    Hasegawa T, Tachibana A, Takeda D, Iwata E, Arimoto S, Sakakibara A, Akashi M, Komori T (2016) Risk factors associated with oroantral perforation during surgical removal of maxillary third molar teeth. Oral Maxillofac Surg 20:369–375

    Article  Google Scholar 

  4. 4.

    Ali IK, Sansare K, Karjodkar FR, Vanga K, Salve P, Pawar AM (2017) Cone-beam computed tomography analysis of accessory maxillary ostium and Haller cells: prevalence and clinical significance. Imaging Sci Dent 47:33–37

    Article  Google Scholar 

  5. 5.

    Harris D, Horner K, Gröndahl K, Jacobs R, Helmrot E, Benic GI, Bornstein MM, Dawood A, Quirynen M (2012) E.A.O. Guidelines for the use of diagnostic imaging in implant dentistry 2011. A consensus workshop organized by the European Association for Osseointegration at the Medical University of Warsaw. Clin Oral Implants Res 23:1243–1253

    Article  Google Scholar 

  6. 6.

    Rege IC, Sousa TO, Leles CR, Mendonça EF (2012) Occurrence of maxillary sinus abnormalities detected by cone beam CT in asymptomatic patients. BMC Oral Health 12:30

    Article  Google Scholar 

  7. 7.

    Timmenga NM, Raghoebar GM, Liem RS, Van Weissenbruch R, Manson WL, Vissink A (2003) Effects of maxillary sinus floor elevation surgery on maxillary sinus physiology. Eur J Oral Sci 111:189–197

    Article  Google Scholar 

  8. 8.

    Chirilă L, Rotaru C, Filipov I, Săndulescu M (2016) Management of acute maxillary sinusitis after sinus bone grafting procedures with simultaneous dental implants placement–a retrospective study. BMC Infect Dis 16(Suppl 1):94

    Article  Google Scholar 

  9. 9.

    Kumar H, Choudhry R, Kakar S (2001) Accessory maxillary ostia: topography and clinical application. J Anat Soc India 50:3–5

    Google Scholar 

  10. 10.

    Sarna A, Hayman LA, Laine FJ, Taber KH (2002) Coronal imaging of the osteomeatal unit: anatomy of 24 variants. J Comput Assist Tomogr 26:153–157

    Article  Google Scholar 

  11. 11.

    Laine F, Smoker W (1992) The ostiomeatal unit and endoscopic surgery: anatomy, variations, and imaging findings in inflammatory diseases. AJR Am J Roentgenol 159:849–857

    Article  Google Scholar 

  12. 12.

    Joe JK, Ho SY, Yanagisawa E (2000) Documentation of variations in sinonasal anatomy by intraoperative nasal endoscopy. Laryngoscope 110:229–235

    Article  Google Scholar 

  13. 13.

    Jones N (2002) CT of the paranasal sinuses: a review of the correlation with clinical, surgical and histopathological findings. Clin Otolaryngol Allied Sci 27:11–17

    Article  Google Scholar 

  14. 14.

    Prasanna L, Mamatha H (2010) The location of maxillary sinus ostium and its clinical application. Indian J Otolaryngol Head Neck Surg 62:335–337

    Article  Google Scholar 

  15. 15.

    Bornstein MM, Horner K, Jacobs R (2017) Use of cone beam computed tomography in implant dentistry: current concepts, indications and limitations for clinical practice and research. Periodontol 2000 73:51–72

    Article  Google Scholar 

  16. 16.

    Schneider AC, Brägger U, Sendi P, Caversaccio MD, Buser D, Bornstein MM (2013) Characteristics and dimensions of the sinus membrane in patients referred for single-implant treatment in the posterior maxilla: a cone beam computed tomographic analysis. Int J Oral Maxillofac Implants 28:587–596

    Article  Google Scholar 

  17. 17.

    Soikkonen K, Ainamo A (1995) Radiographic maxillary sinus findings in the elderly. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 80:487–491

    Article  Google Scholar 

  18. 18.

    Yeung AWK, Tanaka R, Khong PL, von Arx T, Bornstein MM (2018) Frequency, location, and association with dental pathology of mucous retention cysts in the maxillary sinus. A radiographic study using cone beam computed tomography (CBCT). Clin Oral Investig 22:1175–1183

    Article  Google Scholar 

  19. 19.

    Bornstein MM, Yeung AWK, Tanaka R, von Arx T, Jacobs R, Khong PL (2018) Evaluation of health or pathology of bilateral maxillary sinuses in patients referred for cone beam computed tomography using a low-dose protocol. Int J Periodontics Restorative Dent 38:699–710

    Article  Google Scholar 

  20. 20.

    Landis JR, Koch GG (1977) The measurement of observer agreement for categorical data. Biometrics 33:159–174

    Article  Google Scholar 

  21. 21.

    Shanbhag S, Karnik P, Shirke P, Shanbhag V (2014) Cone-beam computed tomographic analysis of sinus membrane thickness, ostium patency, and residual ridge heights in the posterior maxilla: implications for sinus floor elevation. Clin Oral Implants Res 25:755–760

    Article  Google Scholar 

  22. 22.

    Dobele I, Kise L, Apse P, Kragis G, Bigestans A (2013) Radiographic assessment of findings in the maxillary sinus using cone-beam computed tomography. Stomatologija 15:119–122

    PubMed  Google Scholar 

  23. 23.

    Carmeli G, Artzi Z, Kozlovsky A, Segev Y, Landsberg R (2011) Antral computerized tomography pre-operative evaluation: relationship between mucosal thickening and maxillary sinus function. Clin Oral Implants Res 22:78–82

    Article  Google Scholar 

  24. 24.

    Souza AD, Rajagopal KV, Ankolekar VH, Souza ASD, Kotian SR (2016) Anatomy of maxillary sinus and its ostium: a radiological study using computed tomography. CHRISMED J Health Res 3:37–40

    Article  Google Scholar 

  25. 25.

    May M, Sobol SM, Korzec K (1990) The location of the maxillary os and its importance to the endoscopic sinus surgeon. Laryngoscope 100:1037–1042

    Article  Google Scholar 

  26. 26.

    Singhal MD, Singhal D (2013) Maxillary sinus ostium - morphology and its clinical relevance. CIBTech J Surg 2:26–29

    Google Scholar 

  27. 27.

    Van Alyea OE (1936) The ostium maxillare: anatomic study of its surgical accessibility. Arch Otolaryngol 24:553–569

    Article  Google Scholar 

  28. 28.

    Brook I (2009) Sinusitis. Periodontol 2000(49):126–139

    Article  Google Scholar 

  29. 29.

    Manor Y, Mardinger O, Bietlitum I, Nashef A, Nissan J, Chaushu G (2010) Late signs and symptoms of maxillary sinusitis after sinus augmentation. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 110:e1–e4

    Article  Google Scholar 

  30. 30.

    Doud Galli SK, Lebowitz RA, Giacchi RJ, Glickman R, Jacobs JB (2001) Chronic sinusitis complicating sinus lift surgery. Am J Rhinol 15:181–186

    Article  Google Scholar 

  31. 31.

    Mahajan A, Mahajan A, Gupta K, Verma P, Lalit M (2017) Anatomical variations of accessory maxillary sinus ostium: an endoscopic study. Int J Anat Res 5:3484–3490

    Article  Google Scholar 

  32. 32.

    Singhal M, Singhal D (2014) Anatomy of accessory maxillary sinus ostium with clinical application. Int J Med Sci Public Health 3:327–329

    Article  Google Scholar 

  33. 33.

    Vogiatzi T, Kloukos D, Scarfe WC, Bornstein MM (2014) Incidence of anatomical variations and disease of the maxillary sinuses as identified by cone beam computed tomography: a systematic review. Int J Oral Maxillofac Implants 29:1301–1314

    Article  Google Scholar 

  34. 34.

    Pauwels R, Zhang G, Theodorakou C, Walker A, Bosmans H, Jacobs R, Bogaerts R, Horner K (2014) Effective radiation dose and eye lens dose in dental cone beam CT: effect of field of view and angle of rotation. Br J Radiol 87(1042):20130654

    Article  Google Scholar 

  35. 35.

    Seals K, Lee E, Cagnon C, Al-Hakim R, Kee S (2016) Radiation-induced cataractogenesis: a critical literature review for the interventional radiologist. Cardiovasc Intervent Radiol 39:151–160

    Article  Google Scholar 

  36. 36.

    Jaju PP, Jaju SP (2015) Cone-beam computed tomography: time to move from ALARA to ALADA. Imaging Sci Dent 45:263–265

    Article  Google Scholar 

  37. 37.

    Brugger OE, Bornstein MM, Kuchler U, Janner SF, Chappuis V, Buser D (2015) Implant therapy in a surgical specialty clinic: an analysis of patients, indications, surgical procedures, risk factors, and early failures. Int J Oral Maxillofac Implants 30:151–160

    Article  Google Scholar 

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The authors are grateful to Ms. Kar Yan Li, Centralised Research Lab, Faculty of Dentistry, The University of Hong Kong, for her valuable assistance regarding the statistical analysis.


This study has been funded by departmental funds only. No external funding has been received.

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Corresponding author

Correspondence to Michael M. Bornstein.

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The authors declare that they have no conflict of interest.

Ethical approval

All procedures performed were in accordance with the ethical standards of the institutional and/or national research committee and with the Declaration of Helsinki (2013). The study protocol was submitted to and approved by the local institutional review board (IRB) of the University of Hong Kong/Hospital Authority Hong Kong West Cluster (approval number UW 18-227).

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For this type of study (retrospective study) formal consent is not required.

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Yeung, A.W.K., Colsoul, N., Montalvao, C. et al. Visibility, location, and morphology of the primary maxillary sinus ostium and presence of accessory ostia: a retrospective analysis using cone beam computed tomography (CBCT). Clin Oral Invest 23, 3977–3986 (2019).

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  • Maxillary sinus
  • Ostium
  • Cone beam computed tomography
  • Visibility
  • Location
  • Patency