Volume 39, Issue 6 , Pages 615-616, June 2010
Cystic change in alveolar bone graft
Article Outline
Abstract
The authors report a cystic lesion within a previous unilateral cleft lip and alveolus bone graft site in a 15-year-old girl, 5 years after the secondary bone graft. The cyst comprised respiratory epithelial lining, which is thought to be a remnant of the nasal mucosal lining of the primary cleft.
Keywords: alveolar bone graft, alveolar cyst
Alveolar bone grafting is an established method of reconstructing the alveolar cleft. Complications at the cleft site include bleeding, pain, wound breakdown, low-grade infection, bone sequestration, bone loss, bone resorption, residual fistulae, loss of vestibular depth and gingival hyperplasia, injury to adjacent teeth, and external bone resorption.4 The authors present an unusual case of cyst formation within a previously grafted cleft alveolus.
Case report
A 15-year-old Afro-Caribbean girl with right-sided unilateral cleft lip and alveolus had a secondary bone graft in the cleft area with iliac crest cancellous bone graft at the age of 10 years. An upper occlusal radiograph taken 2 months postoperatively demonstrated good bony infill (Fig. 1).
Fig. 1.
Good bony infill 2 months after primary bone graft.
The patient remained under regular multidisciplinary cleft team review. A repeat upper occlusal radiograph of the area was taken 5 years later prior to planned orthodontic treatment (Fig. 2). This showed a radioluscency within the alveolus. The patient was asymptomatic.
Fig. 2.
Radiograph taken 5 years after primary bone graft, showing bone loss.
Repeat alveolar bone grafting was planned for presumed graft loss due to bone resorption. At the time of surgery, a well formed cyst was noted (Fig. 3) measuring approximately 1.5
cm in diameter. The cyst was removed intact and the residual defect was re-grafted with cancellous iliac crest bone.
Fig. 3.
Cyst in the alveolar bone graft area, measuring approximately 1.5
cm (insert).
The histology of the cyst showed cyst wall composed of fibrous and granulation tissue containing lobules of minor secretary glands. The high power image (Fig. 4) shows the cyst wall containing mucous glands and goblet cells within the epithelium, consistent with a sinonasal type epithelium. This confirms it is a benign inclusion cyst of respiratory epithelial type.
Fig. 4.
High power magnification of the cyst showing the wall containing mucous glands and goblet cells within the epithelium.
Discussion
Cyst formation in free bone graft is an unusual complication. Jia et al.2 observed the long term outcome of secondary alveolar bone grafting in 170 patients with various types of cleft. There was no report of cyst development in any of these cases. The only other reported case of a cyst arising in a cleft alveolar bone graft site was reported by Lekkas et al.3 In the latter case, microscopic examination revealed a cystic lesion lined for the most part by pseudostratified ciliated columnar epithelium. Lekkas et al. thought a small particle of respiratory epithelium from the nose was implanted at the time of bone grafting, which proliferated into a cyst. The present case reports similar pathology of inadvertent inclusion of nasal mucosal cells at the time of secondary bone grafting, which proliferated to form a cyst. Cystic degeneration of entrapped nasal mucosal tissues between the bony edges of maxillary osteotomies was postulated by Hayhurst et al.1 Lekkas et al.3 removed the cyst under local anaesthetic and as the defect was small did not repeat bone grafting. In the present case, the defect was larger and the working diagnosis of lost bone graft from resorption led to re-grafting to facilitate orthodontic treatment.
In conclusion, this case reports the rare complication of an inclusion cyst in a previously grafted cleft alveolus comprising respiratory type epithelium, which the authors think has arisen from the nasal mucosal lining. For this reason, in accord with Hayhurst et al.1, the authors advocated that the nasal mucosa should be carefully repaired.
Funding
None.
Competing interests
None declared.
Ethical approval
Not required.
References
- . Surgical ciliated cyst: a delayed complication in a case of maxillary orthognathic surgery. J Oral Maxillofac Surg. 1993;51:705–708[discussion 708–9]
- . Long-term outcome of secondary alveolar bone grafting in patients with various types of cleft. Br J Oral Maxillofac Surg. 2006;44:308–312
- . Cyst arising in a free bone graft. Eur J Plastic Surg. 2001;24:195–196
- . Alveolar bone grafting: how i do it. In: 2nd ed.. Ward Booth P, Schendel SA, Hausamen J editor. Maxillofacial surgery. vol. 2:Churchill Livingstone: Elsevier; 2007;p. 1070
PII: S0901-5027(10)00052-4
doi:10.1016/j.ijom.2010.02.009
© 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.
Volume 39, Issue 6 , Pages 615-616, June 2010
