Journal of Oral and Maxillofacial Radiology

CASE REPORT
Year
: 2018  |  Volume : 6  |  Issue : 3  |  Page : 51--54

Importance of volumetric reformatting in the treatment of maxillofacial lesions: A case report of nasopalatine duct cyst


Lancaster Barbosa Goncalves Junior1, Paulo Henrique Viana Pinto2, Apolo Victor Torres Silva1, Millena Mangueira Rocha3, Jean de Pinho Mendes1, Antonione Santos Bezerra Pinto1,  
1 Department of Dentistry, State University of Piauí, Parnaiba, Piauí, Brazil
2 Department of Pathology and Legal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
3 Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil

Correspondence Address:
Antonione Santos Bezerra Pinto
Rua Maria Teresa Dutra, 90, CEP 64202-475, Parnaíba-PI, Piauí
Brazil

Abstract

With the advent of different imaging examinations, one can avoid misleading diagnosis and inadequate treatments of lesions, such as nasopalatine duct cyst (NPDC). The objective of this article is to report a case of NPDC in which different imaging means were used for diagnosis, treatment, and postoperative follow-up of the lesion. Radiograph of a 20-year-old female patient showed a radiolucent heart-shaped area near the apices of the upper central incisors. Diagnostic hypothesis of NPDC was based on clinical examination and imaging analysis of the lesion. The treatment consisted of enucleation of the lesion after volumetric study, which enabled visualization of its relationship with surrounding noble structures. The diagnosis was confirmed by means of histopathological examination. Differential diagnosis of NPDC was well grounded before intervention, and the lesion was studied in detail using three-dimensional volumetric tools, giving effectiveness and safety to the treatment.



How to cite this article:
Goncalves Junior LB, Viana Pinto PH, Torres Silva AV, Rocha MM, Mendes Jd, Bezerra Pinto AS. Importance of volumetric reformatting in the treatment of maxillofacial lesions: A case report of nasopalatine duct cyst.J Oral Maxillofac Radiol 2018;6:51-54


How to cite this URL:
Goncalves Junior LB, Viana Pinto PH, Torres Silva AV, Rocha MM, Mendes Jd, Bezerra Pinto AS. Importance of volumetric reformatting in the treatment of maxillofacial lesions: A case report of nasopalatine duct cyst. J Oral Maxillofac Radiol [serial online] 2018 [cited 2019 Feb 15 ];6:51-54
Available from: http://www.joomr.org/text.asp?2018/6/3/51/251372


Full Text



 Introduction



The combination of imaging tools assists a dentist surgeon in diagnosing and treating pathologies located in the craniomaxillofacial region, mainly those close to noble structures.[1] Considered the most common nonodontogenic lesion of the maxilla, nasopalatine duct cyst (NPDC) presents uncertain etiopathogeny, although its occurrence is associated with spontaneous proliferation of embryological cell rests of the nasopalatine duct, proliferative reaction of Malassez epithelial rests, or retention of mucus in the region.[2],[3],[4]

Clinically, the patient was asymptomatic but reported pain in the region of incisive papilla, which was explained by the pressure on nasopalatine nerve. When infected, edema and/or purulent drainage can be observed. Radiographically, one can also observe a well-delimited ovoid radiolucent area resembling a heart near the apices of the upper incisors.[3],[5],[6]

Despite these characteristics, misleading diagnoses and inadequate treatments of NPDC have been described in the literature,[6] thus pointing out the importance of detailed analysis of this pathology[7],[8] by means of imaging analysis tools and specific software, such as three-dimensional reformatting of bone structures and soft tissues. This enables the dentist surgeon to evaluate the lesion thoroughly, thus providing surgical predictability and higher likelihood of success.[9]

Therefore, the objective of this article is to report a case of NPDC in which a combination of different imaging modalities was used to assist in diagnosis, treatment planning, and postoperative follow-up of lesion.

 Case Report



Panoramic radiograph of a 20-year-old female patient, taken for orthodontic purposes, showed an asymptomatic radiolucent heart-shaped area near the apices of the upper central incisors [Figure 1]a. Cone-beam computed tomography (CBCT) was ordered, showing a hypodense area in the anterior maxillary region with expansion of cortical bone along the nasopalatine duct canal [Figure 1]b.{Figure 1}

In addition to these examinations, the patient also had been recently submitted to magnetic resonance imaging (MRI), with T1-weighed images showing internal intermediate signal of the lesion as well as homogeneity, indicating the absence of internal calculi (e.g., fatty content). However, sequential images showed hypersignal area delimited by intermediate and hyposignal areas, suggesting liquid content compatible with cystic fluid – with consequent differentiation from tumoral lesion on T2 [Figure 1]c.

In this way, the diagnostic hypothesis of NPDC was raised, and considering its proximity to adjacent structures, three-dimensional reformatting of the region was performed using InVesalius software (Center for Information Technology Renato Archer, Campinas – São Paulo – Brazil). Manual segmentation was used and skeleton automatically generated based on predetermined thresholds. It was possible to observe volume, extension, and positioning of the lesion [Figure 2]a, [Figure 2]b, [Figure 2]c by increasing the bone transparency, which corresponds to its morphology. This allows having surgery predictability as the largest volume of the lesion was near the nasal fossa. By knowing the localization and size of the lesion, it was suggested to perform enucleation as a form of treatment.{Figure 2}

Surgical procedure was initiated under local anesthesia for access to anterior palatine region through flap elevation and osteotomy between the first premolars. Next, the lesion was displaced and removed. In the end, suture was performed to close the surgical wound [Figure 3]a, [Figure 3]b, [Figure 3]c.{Figure 3}

The patient was medicated with analgesics and antibiotics, in addition to being instructed on postoperative care. The removed material was sent for histopathological examination [Figure 3]d, which showed that the lesion consisted of soft tissue fragment measuring 12 mm × 4.0 mm × 4.0 mm and exhibited elongated shape, irregular surface, blackened color, and fibrous consistency [Figure 3]d.

Histological sections [Figure 4]a and [Figure 4]b revealed fragment of cystic capsule consisting of dense connective tissue lined by simple cubic epithelium and ciliated pseudostratified epithelium in certain areas. Blood vessels, clots, and adipose cells were observed within the cystic capsule. Fragments of mineralized tissue completed the picture and confirmed the diagnosis of NPDC.{Figure 4}

Radiographic follow-up showed satisfactory bone repair, continuity of lamina dura, and normal periodontal ligament space in the teeth involved. The heart-shaped area was observed in detail, which was explained by the superposition of the anterior nasal spine [Figure 5]a and [Figure 5]b.{Figure 5}

 Discussion



NPDC affects both males and females, being often seen in adulthood despite the possibility of occurring in young individuals, as in the present case.[4],[9] This lesion is usually discovered by means of routine radiographs,[5] and its diagnosis involves differentiation of anatomical structures and odontogenic lesions.[3],[6]

CBCT and MRI images have allowed for anatomical study of the lesion, but the latter also provided analysis of internal content based on the signal intensities emitted from different tissues.[10] NPDC is a cystic lesion presenting low-intermediate signal intensity on T1, but high-intensity signal on both T1 and T2 can occur due to the presence of proteins and viscous fluid inside the lesion, as demonstrated in this study.[7],[8]

Histopathological findings vary depending on the proximity of the lesion to oral or basal mucosa since one can observe stratified-squamous or pseudostratified columnar (ciliated or caliciform) epithelium, as well as simple columnar or simple cuboidal type.[2],[4],[8] Morphologically, the cystic wall is lined by innervated and vascularized fibrous connective tissue.[2],[4] In addition, hyaline cartilage, mineralized tissues, and cholesterol crystals could also be found.[2],[3] Therefore, the histological findings in the present case corroborate the literature on this lesion.

Despite being benign and having a limited development, NPDC can cause excessive osteolysis in association with hemorrhage, dehiscence, buccosinusal communication, and damage to sensorial nerves of the region.[8],[9] The three-dimensional study of the lesion can assist in overcoming such complications during the treatment, which consists of enucleation or marsupialization.[8]

Therefore, CBCT allows for analysis of the site affected by the lesion in detail and at low-radiation dose.[9],[10] In this case, we have also opted for a topographic reproduction of the lesion by using InVesalius software, which is a free-use tool enabling visualization of NPDC in terms of area and volume, including its relationship with vascular-nervous bundles and nasal floor. With a grounded surgery planning, one can preserve the vitality of the teeth and sensorial activity of anterior palate.[1]

The different imaging modalities combined with clinical examination have allowed us to obtain a well-grounded differential diagnosis before an invasive procedure, and their association with histopathological examination resulted in accurate diagnosis. In the present case report, volumetric reformatting of the lesion was crucial for a successful treatment as it prevented surgical complications and allowed for maintenance of vascular-nervous activity in the region.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal identity.

Financial support and sponsorship

For the elaboration this article, the authors didn't have any financial support or sponsorship.

Conflicts of interest

There are no conflicts of interest.

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