Characteristic MRI and cone beam CT findings in a case of paradental cysts arising in the bilateral retromolar regions of the mandible

Abstract

Paradental cyst is an inflammatory odontogenic cyst in the mandibular area, with a rare occurrence of 0.9-4.7% among odontogenic cysts, developing laterally with the cementoenamel junction of a totally or partially erupted molar. [1,2] It was first described by Main in 1970 [3] and Craig suggested the name paradental cyst. [4] The World Health Organization (WHO) has defined the paradental cyst as a cyst occurring near to the cervical margin of the lateral aspect of a root as a consequence of an inflammatory process in a periodontal pocket. A distinctive form of the paradental cyst arises on the buccal and distal aspects of erupted mandibular molars where there is a history of pericoronitis. [5] Patients report different degrees of pain, tenderness, and swelling and, in some cases, it can be observed along with suppuration through the periodontal pocket. [2,6] Radiographically, the paradental cyst can have different features depending on the superposition of anatomical structures, presence of infection, and size and location of lesion, [2] however, is often presented as a well-defined A B S T R A C T Paradental cyst is an inflammatory odontogenic cyst linked with mandibular molars. The occurrence rate of the lesion ranges from 0.9 to 4.7% suggesting its infrequency. The histopathologic findings in hematoxylin and eosin routine staining are not pathognomonic, and the correlation with clinical and imaging characteristics is essential to establish the final diagnosis. The periapical radiographs show a unilocular radiolucency on the distal or disto/buccal aspect of the involved tooth, however, the lesion can superimpose over the roots and mimic periapical pathology. We report the imaging features of a rare bilateral paradental cyst with an emphasis on magnetic resonance imaging and cone beam computed tomography to help a correct identification and characterization of the cyst and to reliably establish the diagnosis.

Magnetic resonance imaging versus cone beam computed tomography in diagnosis of periapical pathosis – A systematic review

“… CBCT-superior spatial resolution MRI revealed a differential diagnosis of squamous cell carcinoma. 9 Pinto et al, 2016 Brazil Case Report GENDEX GXCB-500 FOV:16X6.0cm Voxel size:0.2mm Achieva 1.5T 8-channel phased-array head coil T1 Repetition Time-478ms Voxel Size:0.72mm isotropic Echo Time:16ms FOV:21X21cm Slice gap:2.0mm T2 Repetition Time-6.5ms Voxel Size:0.72mm isotropic Echo Time:90ms FOV:21X21cm Slice gap:2.0mm A well-defined unilocular lesion with a thin radiopaque border bilaterally adjacent to the area of the third mandibular molars. T1-Intermediate to low signal intensity surrounded by a thin delineation of hypointense compatible with the cortical bone.…”

“…The remaining fifteen incorporated studies have availed both CBCT and MRI to diagnose a periapical lesion that results in the diagnosis of a nonodontogenic disease. The diagnosis reported varied from a benign Stafne’s bone cyst ( Ertas et al, 2015 ), a paradental cyst ( Pinto et al, 2016 ), lymphangioma ( Rodrigue et al, 2011 ) and myofibroma ( Adachi et al, 2015 ) to a malignant non-Hodgkin’s lymphoma ( MacDonald et al, 2017 ), breast carcinoma metastasis ( Veken et al, 2018 ) and squamous cell carcinoma ( Choi et al, 2012 , Hendrikx et al, 2010 , Galvão et al, 2019 ). Benign lesions such as ameloblastoma ( Gamba et al, 2016 ) and keratocystic odontogenic tumour ( Pinto et al, 2016 ) that could turn aggressive if left untreated were diagnosed aptly using CBCT and MRI.…”

“…The diagnosis reported varied from a benign Stafne’s bone cyst ( Ertas et al, 2015 ), a paradental cyst ( Pinto et al, 2016 ), lymphangioma ( Rodrigue et al, 2011 ) and myofibroma ( Adachi et al, 2015 ) to a malignant non-Hodgkin’s lymphoma ( MacDonald et al, 2017 ), breast carcinoma metastasis ( Veken et al, 2018 ) and squamous cell carcinoma ( Choi et al, 2012 , Hendrikx et al, 2010 , Galvão et al, 2019 ). Benign lesions such as ameloblastoma ( Gamba et al, 2016 ) and keratocystic odontogenic tumour ( Pinto et al, 2016 ) that could turn aggressive if left untreated were diagnosed aptly using CBCT and MRI. In a case report that presented pulp necrosis with apical periodontitis and paresthesia, the application of CBCT and MRI led to the diagnosis of Vincent’s Symptom ( Christovik et al, 2018 ).…”

Cisto paradental: Relato de caso clinico

“…O exame histopatológico dos cistos paradentais revela uma cápsula cística alinhada por um epitélio escamoso estratificado esponjoso hiperplásico, não queratinizado, de diferentes espessuras. A cápsula é composta de tecido conjuntivo fibrovascular apresentando vasos hiperémicos, hemorragia em áreas focais, infiltrado de células inflamatórias crónicas e vasos sanguíneos, 25,26 estando em conformidade com os achados histológicos do presente caso.…”