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2026 Vol.30, Issue 1 Preview Page

Clinical or Case Report

Unexpected Spontaneous Bone Formation Beyond the Boundary of the Grafted Area Following Lateral Maxillary Sinus Floor Augmentation: A Report of Four Cases
Won-Bae Park1†
,
Gyutae Kim2†
,
Young Woo Song3
,
Seungil Shin4
,
Hyun-Chang Lim5*
1Dentist, Private Practice in Periodontics and Implant Dentistry, Seoul, Korea
2Professor, Department of Oral and Maxillofacial Radiology, Kyung Hee University College of Dentistry, Kyung Hee University Medical Center, Seoul, Korea
3Director, Department of Periodontology, Veterans Health Service Medical Center, Seoul, Korea
4Professor, Department of Periodontology, Kyung Hee University, College of Dentistry, Periodontal-Implant Clinical Research Institute, Kyung Hee University Medical Center, Seoul, Korea
5Associate Professor, Department of Periodontology, Kyung Hee University, College of Dentistry, Periodontal-Implant Clinical Research Institute, Kyung Hee University Medical Center, Seoul, Korea
*Corresponding Author
†These authors equally contributed to this work.
31 March 2026. pp. 42-50
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Abstract

Maxillary sinus floor elevation (MSFE) is a common procedure to address insufficient bone height in the posterior maxilla for implant placement. In MSFE, bone substitute grafting is commonly employed to create space for new bone formation, which is typically confined to the grafted area. Conversely, this case study demonstrates unexpected spontaneous bone formation (SBF) beyond the grafted region. In four patients, lateral MSFEs with or without simultaneous implant placement were performed. Sinus membrane perforation was not detected during MSFE. Cone-beam computed tomography (CBCT) was obtained pre-operatively, at 1 week, at prosthesis delivery, and during follow-up. Early CBCT revealed significant sinus mucosal swelling and varying graft particle dispersion, without clinical signs of infection. Subsequently, new bone formed beyond the grafted region, particularly along the lateral sinus wall, with progressive maturation and cortical thickening. All implants achieved functional stability. These findings suggest that post-operative events such as bleeding, transient mucosal thickening, or possible undetected membrane perforation may create additional space beyond the grafted area, which subsequently undergoes bone formation. The clinical impact of SBF may be limited, but it provides insight into the osteogenic potential of the sinus environment.

Keywords
Bone transplantation
Case reports
Dental implant
Maxillary sinus
Sinus floor augmentation
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Information
  • Publisher :The Korean Academy of Oral & Maxillofacial Implantology
  • Publisher(Ko) :대한구강악안면임플란트학회
  • Journal Title :Journal of implantology and applied sciences
  • Journal Title(Ko) :대한구강악안면임플란트학회지
  • Volume : 30
  • No :1
  • Pages :42-50
  • Received Date : 2026-02-03
  • Revised Date : 2026-03-22
  • Accepted Date : 2026-03-23
  • DOI :https://doi.org/10.32542/implantology.2026004
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