Peripheral giant cell granuloma (PGCG) is a benign hyperplastic reactive lesion which is a relatively uncommon lesion of the oral mucosa. PGCG originates from the periodontal ligament or mucoperiosteum and is usually caused by local irritation or chronic trauma. The etiology of PGCG is unknown. Local irritation factors such as poor dental restorations, unstable dental prosthesis, dental extractions, plaque and calculus accumulation, and food retention seem to play a significant role in the development of a PGCG.2,3,5,9–11
Histopathologic characteristics of PGCG may be consistent with periodontal ligament or periosteum origin.4
Histologically, PGCG is identified as a non-encapsulated mass of tissue compiled of a reticular and fibrillar connective tissue stroma containing profuse young connective tissue cells of ovoid or fusiform shape, and multinucleated giant cells.8
The fibrocellular reaction is akin to that of other reactive lesions such as fibrous hyperplasia and peripheral ossifying fibroma.10–12
The calcified material or newly formed bone may also be seen all over the cellular connective tissue, and some of the lesions may be either woven bone or lamellar bone produced by the mononuclear stromal cells, which might be similar to latent proliferative osteoblasts or osteoprogenitor cells.5,6,13
The microscopic appearance of PGCG is distinctive mainly due to the large number of multinucleated giant cells that are disseminated in the connective tissue stroma.4
The exact basis of the giant cells is still uncertain. Many opinions have been offered in the literature, as osteoblasts, phagocytes, endothelial cells, and spindle cells are thought to be responsible for giant cell proliferation.6,14
The widely reported discrepancy in the gender ratio may mirror the small number of cases considered in some series, but the majority of studies agree that there is a female predominance.15
In this report, two of our three patients were female. PGCG is seen in almost every decade group, but most patients were aged between four and seven decades, as reported in previous studies.4,5,7
Two of our patients were in the five-decade age cohort and one patient was in the eighth decade. The affected site for all patients in this report was the anterior mandible. In the literature, PGCG is more common in the lower jaw than in the upper jaw.4,5
Clinically, PGCG is a smooth brown, red, or bluish nodule, sessile or pedunculated. Radiographic examinations generally have no findings, because the lesion is a soft tissue mass. Although the etiology of PGCG is unclear, in the present report the etiologic factor is thought to be chronic trauma, because of unstable prosthesis. Our three patients have used complete dentures for numerous years. PGCGs generally develop either in the gingival tissue or in the alveolar processes of the incisor and canine region.3
Of our three cases, all were located in the edentulous alveolar margins of the anterior mandibular region. Lesion size differs from 0.5 to 1.5 cm in diameter, although there have been 5 cm size cases in the literature, in which factors such as poor oral hygiene or xerostomia seem to play an important role in lesion growth.4
None of our cases exceeded 2 cm in size.
In the present report, all three cases have had long-term use of complete dentures that might be thought of as having the possible effect of unstable dental prostheses on PGCGs etiology. The most preferred occlusion type for complete dentures is bilateral balanced occlusion (BBO). In BBO, the anterior teeth do not make contact during functional movements ().16
Over time, as a result of posterior denture erosion, anterior teeth may contact.17
These contacts may cause resorption on residual ridges and so soft tissues can lose bone support and, after all these changes, increased forces may create irritation on these areas.16,18,19
This may be an irritant factor for PGCG development. Edentulous patients wearing complete dentures should be followed up at one-year intervals and should be considered for implant-supported dentures to prevent soft tissue trauma. Complete dentures should be re-fabricated every five years even for asymptomatic cases in order to avoid possible development of reactive lesions such as PGCG.
Clinical view of the post prothetic treatment of first patient.