2021, Number 4
Circumferential dentigerous cyst associated with oronasal inverted mesiodens: case report
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ABSTRACT
Introduction: the dentigerous cyst is a developmental odontogenic cyst characterized by surrounding the crowns of unerupted or developing teeth whose exact pathogenesis is still unknown. These lesions are rarely associated with supernumerary teeth, accounting for 5 to 6% of all reported dentigerous cysts; 90% develop around mesiodens in the anterior maxilla, with few reports associated with inverted mesiodens. Additionally, few cases of variants of circumferential dentigerous cysts have been identified, which surround the tooth, being a rare entity whose differential diagnosis represents a challenge. Objective: to present the case of a rare circumferential variant of the dentigerous cyst of oronasal localization associated with an inverted supernumerary tooth in the upper maxilla. Case report: a 43 years old male patient, systemically healthy, reports pressure in the anterior maxilla. Clinically, vestibular and palatine tumor mass of firm consistency, covered by regular mucosa, is felt. Radiographic examination revealed a cortical osteolytic area with radiopaque foci. In addition, a CBCT showed a cystic lesion, cranially related to an inverted mesiodens. A decompression cannula is installed, and an incisional biopsy is performed. Histopathological analysis shows a cystic membrane with non-keratinized squamous epithelial lining and dystrophic calcifications foci. Therefore, the dentigerous cyst diagnosis is proposed. After six months, a control was performed with panoramic radiography and CBCT; a decrease in lesion size was observed. The consequent surgical enucleation is performed with the subsequent filling of the bed with lyophilized bone without recurrences at six months. Conclusion: due to the clinical behavior of this lesion and its particular location, clinical examinations, imaging, and histopathological studies are essential to formulate a correct diagnosis and treatment plan.INTRODUCTION
The dentigerous cyst, also known as a follicular cyst, is an odontogenic cyst from cells of the reduced enamel epithelium.1 It is characterized by surrounding the crown of an unerupted or developing tooth, which is attached to the tooth's neck at the cementum-enamel junction.1,2 Although its pathogenesis is uncertain, it has been suggested that the pressure by an erupting tooth in the follicle may obstruct venous flow by inducing the accumulation of exudate between the reduced enamel epithelium and the crown of the tooth. On the other hand, some research reports that inflammatory processes at the periapical level of non-vital deciduous teeth near the follicles of permanent successors could constitute a risk factor associated with the appearance of dentigerous cysts.2,3 These account for 24% of odontogenic cysts and rank second in frequency of maxillary cysts.3 They appear mainly in males in the second or third decades and rarely in children (less than 2% incidence). They are often asymptomatic, so they are frequently radiographic findings, which can generate significant bone expansions, with pathological fractures, erosions, rizolisis, tooth mobility, and even superinfections, so they are considered the most aggressive odontogenic cysts.3-5
Radiographically it is observed as a well-defined unilocular radiolucency surrounding the crown of an unerupted tooth and may present cortical radiopaque margins;5 however, a histopathological study is necessary for its definitive diagnosis.1-5 Frequently (approximately 75%), it is located at lower third molars. Although it is generally associated with permanent teeth, 5% has been associated with supernumerary teeth, with mesiodens being the most affected.5-7
The prevalence in mesiodens is 0.15 to 1.9%; clinically, the dentigerous cyst due to a supernumerary tooth occurs in the first four decades of life.8 In addition, supernumerary teeth may appear alone or multiple, unilateral or bilateral, erupted or impacted, and occur in the maxilla or mandible. It has been reported that the direction of mesiodens eruption may be regular, horizontal, or, the most frequent, inverse9,10 and whose presence may generate complications such as dental impaction, crowding, diastema formation, tooth mobility, occlusal interference, caries, periodontal problems, and appearance of dentigerous cysts11 as is the case that is reported.
There are few reports in the literature about the association of dentigerous cysts with inverted mesiodens and even rarer the association with circumferential dentigerous cysts. Therefore, the aim is to present the therapeutic management of a circumferential variant of the dentigerous cyst associated with an oronasal inverted mesiodens.
CASE REPORT
A 43-year-old male patient consults for increased volume on the palate. Without a systemic history, he reports moderate, intermittent, localized pain with oppressive sensation in the maxillary anterosuperior sector, with unknown evolution time. On clinical examination, a tumor mass is observed in the vestibule's and palate's background, extended from DO 2.2 to 1.1, rounded, firm consistency, covered by normal mucosa, painful on palpation, and of defined borders. The teeth involved had cavities but were vital to endodontic tests without mobility or displacement (Figure 1A).
At the beginning, a large radiolucent lesion and the integrity of periodontal spaces in the compromised teeth were radiographically observed, so panoramic radiography and CBCT were requested; these studies revealed a circumscribed osteolytic lesion, well delimited with cortical margins concerning teeth roots 1.1 to 2.2, confirming the presence of a cystic lesion in the anterosuperior maxillary area associated with the existence of inverted supernumerary tooth of bucconasal location, with the crown projected towards the nasal cavity and the root oriented to the oral cavity, with diameters of 2.5 × 2 × 1.9 cm. In addition, expansion of the vestibular and palatine boney cortical was evidenced, generating a displacement of the nasopalatine duct without compromising the roots of adjacent teeth (Figure 1B).
After informed consent was granted, an incisional biopsy was performed under local anesthesia; subsequently, a decompression cannula was installed to decrease the lesion size. Then, grooming with 0.12% chlorhexidine was indicated three times daily with radiographic follow-up at six months (Figure 2A). With the probable diagnosis of adenomatoid odontogenic tumor, the samples obtained were sent to histopathological study; it showed a cystic membrane with a non-keratinized squamous epithelial lining of a few layers and dystrophic calcifications foci, all suggestive features of a dentigerous cyst. A new clinical and imaging evaluation was conducted six months after the intervention. The patient reported a lesion size decrease and cessation of oppressive symptoms related to the anatomical sector involved. Radiographically, a reduction in the cystic lesion size in the anterosuperior sector was observed, with a diameter of 1.4 × 1.7 × 1.5 cm, associated with the presence of decompression cannula in its thickness (Figure 2B-D).
A new surgical intervention was performed under local anesthesia, and enucleation and cystic removal were performed with bone curettage with supernumerary tooth extraction. Finally, the cavity filling was made with xenogenic lyophilized bone micro particulates (Alpha Bio's Graft) plus a collage resorbable membrane (MEDPRIN ReDuraTM), finally suturing the compromised mucosa (Figure 3A and B). The sample obtained (Figure 3C) was sent again to histopathological analysis evidencing metaplasia of non-keratinized squamous cystic epithelium, surrounded by a capsule of loose connective tissue with chronic inflammatory infiltrate, confirming the diagnosis of a dentigerous cyst (Figure 3D). After six months of follow-up of the lesion, no recurrence was observed (Figure 4).
DISCUSSION
The usual location of the dentigerous cyst is related to non-erupted permanent teeth at the level of the lower third molar. However, 5% have been associated with supernumerary teeth, so these reports about mesiodens are rare,1,12 as is the case we report. Additionally, published papers on dentigerous cysts allude to their common variant where the lesion surrounds the crown of the affected tooth. However, two additional variants of dentigerous cysts are described radiographically in the literature: the lesion may be found laterally (along the root of the tooth partially covering the crown) and a circumferential variant (when the cyst in addition to surrounding the crown, extends downwards along the surface of the root, thus giving the impression of the tooth inside the cyst) as is the case we are presenting, being an infrequent finding, and worthy of being informed.13,14
The rarity of this variant would be related to the displacement produced by the osmotic pressure generated by these cysts creating these anatomical variations.15 Furthermore, the persistence of this lesion has been associated with pathological complications, such as pathological bone fractures, root resorption or neighboring tooth displacement, and oronasal fistulas due to the extent of the lesions between the oral and nasal cavity,2,15 as the case reported in this paper, and even large inflammations and deformations of the upper lip have been reported.15,16 This information is crucial since differential diagnoses are associated with these variants, such as an adenomatoid odontogenic tumor, unicystic ameloblastoma, Pindborg tumor, and odontogenic fibroid.2,12,17
Several treatment plans for managing these lesions have been described in the literature, but there is no consensus on the criteria for selecting the appropriate treatment modality. The choice should be based on the size and location of the cyst, age, affected teeth, and the relationship to surrounding structures.14 Methods used for removal include decompression, marsupialization, and enucleation.
However, the criteria for selecting these treatment modalities are not clearly defined. Additionally, in the literature, there is a lack of studies and long-term follow-up to evaluate treatment outcomes and recurrences and compare demographic data; enucleation and removal of the affected tooth are the most used method since it has been reported to be therapeutic method with the lowest rate of recurrence.
The use of different graft materials to fill the residual cavity has also been reported, including alloplastic bone, allogeneic bone, xenogenic bone, or a combination of these materials; autogenous cellulose grafts produce the most favorable and predictable results, both experimentally and clinically.14,17-19
In our case, decompression was preferred with subsequent enucleation at six months with the extraction of the supernumerary tooth. Then the cavity was filled with xenogenic lyophilized bone micro particulates.
CONCLUSION
The appearance of dentigerous cysts associated with inverted supernumerary teeth in the anterior region of the maxilla is unusual, with inverted mesiodens being the most prevalent.
Early detection based on a complete clinical and radiographic examination is necessary for accurate diagnosis and proper treatment planning to prevent such lesions and avoid unwanted effects on adjacent teeth and neighboring anatomic structures. Besides, histopathological analysis is essential to formulate the differential diagnosis with potentially invasive or malignant lesions.
REFERENCES
AFFILIATIONS
1 Cirujano Dentista, Servicio de Cirugía Oral y Maxilofacial, Hospital San Juan de Dios. Santiago, Chile.
2 Cirujano Dentista, Facultad de Odontología, Universidad Finis Terrae. Santiago, Chile.
3 Cirujana dentista, especialista en Patología Oral y Maxilofacial, Hospital de la Serena, La Serena, Chile.
4 Cirujana Dentista, especialista en Radiología Oral y Maxilofacial, Facultad de Odontología, Universidad Finis Terrae, Santiago, Chile.
5 Cirujano Maxilofacial, Servicio de Cirugía Maxilofacial, Hospital de Carabineros. Santiago, Chile.
CORRESPONDENCE
Andrés Noah Melián Rivas. E-mail: andresmelianrivas@gmail.comReceived: Marzo 2020. Accepted: Junio 2020.