Surgical approach associated with cryotherapy of unicystic mandibular ameloblastoma with 19-year follow-up – a case report

Ameloblastoma is a benign odontogenic tumor of epithelial origin with slow, asymptomatic, rare growth and is associated with a high rate of recurrence, being responsible for 1% of mandibular tumors. There are several variations of these tumors, with solid / multicystic and unicystic types being the most recurrent. The signs are discrete and rarely noticed by the patient in the early stages. In the imaging examination, it presents itself as a well-delimited radiolucent image, which may be associated with the crown of an unerupted tooth, resorption of adjacent roots and vestibular-lingual medullary expansion. In the literature, the most appropriate treatment for the management of such pathology is still controversial, since there are conservative philosophies such as curettage, marsupialization (decompression) and defending currents of the radical surgical approach through resection with a safety margin. This study aims to report a case of curettage of follicular unicystic ameloblastoma with a single incidence of recurrence and treated again by means of a conservative surgical approach and continuing with a 19-year clinical preservation, without any clinical or imaging signs of recurrence.

Use of artificial intelligence to recover mandibular morphology after disease

Mandibular tumors and radical oral cancer surgery often cause bone dysmorphia and defects. Most patients present with noticeable mandibular deformations, and doctors often have difficulty determining their exact mandibular morphology. In this study, a deep convolutional generative adversarial network (DCGAN) called CTGAN is proposed to complete 3D mandibular cone beam computed tomography data from CT data. After extensive training, CTGAN was tested on 6 mandibular tumor cases, resulting in 3D virtual mandibular completion. We found that CTGAN can generate mandibles with different levels and rich morphology, including positional and angular changes and local patterns. The completion results are shown as tomographic images combining generated and natural areas. The 3D generated mandibles have the anatomical morphology of the real mandibles and transition smoothly to the portions without disease, showing that CTGAN constructs mandibles with the expected patient characteristics and is suitable for mandibular morphological completion. The presented modeling principles can be applied to other areas for 3D morphological completion from medical images. Clinical trial registration: This study is not a clinical trial. Patient data were only used for testing in a virtual environment. The use of the digital data used in this study was ethically approved.

Metastatic Biphasic Primitive Tumor in the Mandible of a Child

Pediatric mandibular tumors present an aggressive biological behavior and difficult diagnosis. A wide range of odontogenic and nonodontogenic tumors comprise the spectrum of these lesions. We report a case of a 1-year-old male child patient showing facial asymmetry symptomatic of an expansive lesion extending throughout the body and ramus of the left hemimandible with a diameter of 8 cm. The histopathological report suggested a high-grade mucoepidermoid carcinoma (MEC), recommending further immunohistochemical investigation of the ectomesenchymal or neuroectodermal origin of the tumor cells. The patient evolved with extensive bilateral pleural effusion followed by metastasis in the middle third of the right humerus, and died 2 months after the first biopsy procedure by acute renal failure with tubular necrosis, before a final inconclusive immunohistochemical report was reached. The lack of resources for less-favored regions of Brazil impairs rapid biomolecular examinations such as immunohistochemical resulting in delay of appropriate therapeutic procedures.

Recovering Mandibular Morphology after Disease with Artificial Intelligence

Mandibular tumors and radical oral cancer surgery often cause bone dysmorphia and defects. Most patients present with noticeable mandibular deformations, and doctors often have difficulty determining their exact mandibular morphology. In this study, a deep convolutional generative adversarial network (DCGAN) called CTGAN is proposed to complete 3D mandibular cone beam computed tomography (CBCT) data from CT data. After extensive training CTGAN was tested on 6 mandibular tumor cases, resulting in 3D virtual mandibular completion. We found that CTGAN can generate mandibles with different levels and rich morphology, including positional and angular changes and local patterns. The completion results are shown as tomographic images combining generated and natural areas. The 3D generated mandibles have the anatomical morphology of the real mandibles and transition smoothly to the portions without disease, showing that CTGAN constructs mandibles with the expected patient characteristics and is suitable for mandibular morphological completion. The presented modeling principles can be applied to other areas for 3D morphological completion from medical images.Clinical trial registrationThis study is not a clinical trial. Patient data were only used for testing in a virtual environment. The use of digital data used in this study was ethically approved.

Mandibular reconstruction of the chin area in patients with tumors of the maxillofacial region and oral mucosa

Background. Locally advanced squamous cell carcinoma of the oral cavity invades the mandible in 13–38 % of cases. Even a small segmental resection of the mandible, for instance, in the chin area, causes significant functional and cosmetic impairment and requires immediate reconstruction of the bone defect. Currently available methods of defect closure require a comparative assessment.Materials and methods. This article is based on the outcome data from patients with mandibular tumors treated from 1998 through 2018. We identified 471 cases of mandibular surgery including marginal resection and midline mandibulotomy; 203 (43.1 %) patients underwent segmental resection. Of them, we selected 99 patients with an isolated chin defect combined either with a mandibular body defect or with a subtotal defect in the mandible.Results. In this study, we analyzed the treatment outcomes in patients with primary and secondary mandibular tumors involving the chin as the most difficult for reconstruction from the point of view of the surgeon and the most important for the patient from the functional and aesthetic point of view.Conclusions. A mandibular defect located in the chin area requires immediate reconstruction. The preferable method of defect closure is the application of a reconstruction plate with a musculocutaneous flap or implantation of vascularized bone grafts. Implantation of a fibular free flap is preferable for the closure of extensive mandibular defects involving the chin area.

The Pull-Through Technique: A Viable Option for Preserving the Inferior Alveolar Nerve during Surgical Resection

The aim of this study was to present a new surgical technique used to remove benign mandibular tumors with minimal damage to the inferior alveolar nerve. The pull-through technique was shown using an ameloblastoma surgical resection as an example. This technique consisted in the reconstruction of the lower jaw associating the resection of the lesion with nerve repair at the same surgical time. The resection was performed using the pull-through technique and the inferior alveolar nerve was preserved. After 6 months, the patient presented a recovery of approximately 80% of sensory function. The surgical technique presented should be considered an important method by which to produce a higher functional outcome to remove benign mandibular tumors with minimal damage to the inferior alveolar nerve and allows the maintenance of quality of life for the patient, as the consequences of this type of surgery are minimized.