Buccal bifurcation cyst

In regard to the epidemiology of Buccal Bifurcation Cyst, the prevalence of Buccal Bifurcation Cyst has been roughly measured in fewer than 1% of all odontogenic cysts.^[7] To the best of our knowledge, no maxillary BBC instances have been documented in the English literature, indicating how rare maxillary occurrence is. Ruddocks et al. conducted an analysis around 2022 and found that 32 studies published since 1970 reported 82 BBCs, all of which were found in the mandible.^[8] A rare inflammatory odontogenic cyst that typically affects children in their first ten years of life is called a buccal bifurcation cyst (BBC).^[2] Most situations are unilateral, however up to 30% of all BBCs may be bilateral, which can be confusing for new practitioners.^[9]

The exact etiology of BBC is still unclear, but several theories have been suggested regarding its formation.^[10]

One hypothesis suggests that inflammation arises when the tooth penetrates through the oral mucosa during eruption, leading to the proliferation of epithelial cells and cyst formation.^[11] Another theory proposes that a tilted mesiobuccal cusp and deep periodontal pockets might lead to inflammation.^[10]

Additionally, enamel projections from the cemento-enamel junction, in the cervical region of tooth, extending into the furcation, along with reduced enamel epithelium, may make teeth more prone to buccal pocket formation, which can subsequently expand due to pericoronitis and ultimately lead to cyst formation.^[10][11]

A buccal bifurcation cyst (BBC)  is a rare type of cyst that originates from the tissues involved in tooth development (odontogenic cyst). It typically forms on the buccal aspect (cheek side) of mandibular molars, particularly affecting children between the ages of 5 and 13.^[12] This condition is unique because it is linked to the eruption of molars, but the exact process behind its development is still not completely understood.^[12]

The exact cause of BBC remains unclear, but there are a few possible explanations. One theory suggests that chronic inflammation  during the eruption of molars could be a significant factor.^[13] Since the developing molar is positioned close to the buccal gingiva, food and bacteria can easily get trapped in the gum tissue around the tooth, leading to inflammation.^[13] This constant irritation could cause the epithelial rests, which are cells that stay behind after tooth formation (like the rests of Malassez), to form a cyst.^[13]

Other contributing factors could include mechanical trauma from the erupting tooth or environmental irritants that.^[13] Since these cysts often develop when children’s molars are coming in, it’s thought that they might form in response to occlusal (biting) forces or the pressure exerted during eruption.^[13]

When examined under a microscope, BBCs are lined by non-keratinized stratified squamous epithelium, similar to other types of cysts caused by inflammation.^[13] This lining can be thin but might show areas of hyperplasia (thickening) in response to irritation.^[13] The tissue around the cyst is often inflamed, filled with immune cells like lymphocytes, plasma cells, and neutrophils, which indicates the body’s reaction to the inflammation.^[13] You may also see foamy macrophages inside the cyst, which are typical in long-lasting inflammatory conditions.^[13]

Inflammation plays a huge role in how BBCs form. When the molar is erupting and inflammation starts, different immune signals, called cytokines (like IL-1 and IL-6) and tumor necrosis factor-alpha (TNF-α), are released.^[9] These signals attract immune cells to the area, which break down the bone near the cyst through osteoclastic activity (bone resorption).^[9] This leads to the characteristic bone destruction, particularly in the buccal cortical plate of the mandible.^[9] Despite this, the roots of the affected tooth are usually not damaged, which helps differentiate BBCs from other types of cysts.^[9]

Once a BBC forms, it grows due to hydrostatic pressure within the cyst.^[12] The epithelium lining the cyst produces fluid, causing the cyst to expand and further resorb the surrounding bone.^[12] Fortunately, BBCs tend to grow slowly and usually do not cause severe symptoms, aside from noticeable buccal swelling.^[12] Because of this, these cysts are typically not aggressive and don’t destroy the surrounding tissues.^[12]

In conclusion, the development of buccal bifurcation cysts is closely related to inflammation during molar eruption, with epithelial proliferation leading to cyst formation.^[13] The cyst grows through a combination of inflammatory and developmental processes.^[13] Although we don’t fully understand the pathogenesis of BBC, it involves a mixture of inflammation, mechanical forces, and environmental factors.^[9] The prognosis is excellent with proper treatment, as BBCs are generally non-aggressive and respond well to surgery.^[12]

Buccal bifurcation cysts (BBC) occur in children between the ages of 4 and 14 years, and they usually appear during the first decade of life as a pediatric lesion.^[10] Clinically, deep periodontal pockets are observed on the buccal aspect of the affected tooth, accompanied by buccal expansion.^[14][15] Most BBC affects the vital first or second permanent mandibular molars (buccal aspect), which are occasionally present bilaterally.^{[14][15][16][17]} The symptoms typically emerge around the time of the molar erupts, with the patient experiencing mild tenderness and discomfort on the buccal side of the tooth.^[14][18] Swelling is commonly observed, and the patient often reports a foul-tasting discharge.^[14] BBC is often asymptomatic; however, infection with pus drainage and pain can also be present.^[17]

Panoramic(figure 1) and apical(figure 2) radiographs are commonly utilised in routine examinations to aid in the initial detection of BBC.^[15] BBC is characterised by a well-defined radiolucent lesion on the buccal aspect of the tooth extending from furcation to the root apices.^[19][20] With the presence of periosteal reaction on the buccal aspect of the tooth.^[21][22] Tilting of the affected molars, with the apices of the roots tilted lingually and cusp tip buccally.^[21][22] Unlike a periapical cyst, the periodontal ligament space and lamina dura remain intact and continuous, suggesting that the lesion is not directly associated with the root apices.^[15][21][22]