The aim of this study was to systematically review scientific literature in orderto describe the characteristics and prognosis of malignant entities developing from odontogenic cysts. A search in Pubmed (MEDLINE) and Cochrane databases was conducted. The inclusion criteria were articles published in English related to the malignisation of odontogenic cysts in humans. The exclusion criteria were articles that do not specify the type of odontogenic cyst, malignisation of parakeratinised keratocysts, the presence of an ameloblastic carcinoma and metastasis from distant primary tumours. The selected articles were classified according to Strength of Recommendation Taxonomy criteria. Statistical analysis of the data was carried out using statistical package software SPSS version 22.0. From the 1,237 articles initially obtained, the authors included 3 case series and 45 case reports in the end. Descriptive analysis showed that men have a disposition for malignisation from odontogenic cysts and they frequently appear at the posterior mandible, with pain and swelling being the most frequent signs and symptoms. Follicular cysts were the entities that underwent the most malignant changes with well differentiated squamous cell carcinomas being the most prevalent type of malignancy. The real prognosis of this malignancy is not known because of the heterogeneity of available studies. Key words:Odontogenic cysts, squamous cell carcinoma, neoplastic cell transformation, oral cancer.

BackgroundBifid mandibular condyle (BMC) constitutes an extremely rare disorder characterized by a duplication of the head of the mandibular condyle. Its prevalence ranges from 0.31% to 1.82% in the published literature.ObjectivesThe primary objective was to describe the main etiological, clinical and radiological characteristics of patients with BMCs and the existent treatment options. The secondary objective was to simultaneously include the characteristics of two new cases of BMC.Material and MethodsAn electronic search in Pubmed (MEDLINE), Scopus and The Cochrane Library was carried out by two independent reviewers until April 2018. Prospective or retrospective cohort studies, case series and case reports describing clinical and/or radiological characteristics of patients with BMC were included. Registered variables were demographic, etiological factors, diagnostic exam, clinical characteristics and treatment options. The results from the articles selected were organized in a Table along with the characteristics of two new cases of BMC provided by the authors.ResultsFrom a total of 431 articles found in the initial search, 68 articles were finally included. This systematic review included 216 patients and 270 BMC with an average age of 30.6 (SD=14.7) years and a women:men ratio of 1.4:1. Mediolateral condylar orientation was the most prevalent position (80.1%). Among cases with known etiology, 40.8% of cases had a history of traumatism, while 55.9% did not present any relevant medical background. Half of the symptomatic cases had history of trauma. The most common symptoms were hypomobility (22.7%), arthralgia (18.1%), articular noise (17.2%) and ankylosis (17.6%). Active monitoring and manufacturing an occlusal splint were the most frequent treatment options.ConclusionsBMC may have congenital or traumatic etiology. Hypomobility and arthralgia are the most frequent symptoms and treatment options are often conservative. Key words:Bifid mandibular condyle, trifid condyle, tetrafid condyle, condylar orientation, ankyloses.

BackgroundDentigerous cyst appears surrounding the crown of an included tooth. On the radiographic exam, a radiolucent rounded well-defined lesion can be observed.Material and MethodsThis study reports a clinical case of a 34-years old man with a pericoronal radiolucent lesion associated to an impacted lower third molar with the presence of radiopaque material inside. The radiological differential diagnosis was calcifying odontogenic tumor, adenomatoid odontogenic tumor and dentigerous cyst. The impacted third molar was removed and the lesion was sent for the histopathological exam.ResultsThe histopathological diagnosis was dentigerous cyst with capsular calcifications. Specifically, parietal calcifications on its connective wall and a piece of cemento-osseous tissue inside.ConclusionsNon-neoplastic lesions such as dentigerous cysts could develop radiopacities inside the radiolucent pericoronal area. Key words:Dentigerous cyst, calcifications, third molar, differential diagnosis.

Background The main objective of this systematic review was to collect the pre-existing scales for assessing the difficulty of third molar extraction. The secondary objective was to design a proposal for a preoperative evaluation protocol for the difficulty of third molar extraction. Material and Methods Two independent researchers conducted an electronic search in Pubmed (MEDLINE), Cochrane, and Scopus databases during March 2021. Included studies evaluated the prediction of the difficulty of surgical removal of impacted upper or lower third molars using new indices/scales or pre-existing scales with or without modifications. Articles referring to coronectomies or assessing pre-surgical difficulty using other tools were excluded. Neither language nor publication date restrictions were applied. Results Out of 242 articles, 13 prospective cohort studies were finally selected. Seven developed new indices/scales, and 6 assessed the predictive ability of some pre-existing scales. Most of the indices/scales contained radiological variables and few added any patient-related variables. We proposed a preoperative assessment protocol of the difficulty of third molar extraction to facilitate treatment planning and/or considerate referral in cases of high difficulty. This proposal used patient-related, radiological and surgical variables. Conclusions Using a preoperative protocol to evaluate the surgical difficulty, including different patient-specific, radiological and surgical variables, could facilitate treatment planning, help clinicians prevent complications and assess the possibility of referral. Key words: Wisdom teeth, patient characteristics, radiological variables, surgeon experience, assessment form.

Background Odontogenic keratocysts (OKC) are cystic lesions appearing in the jaws, usually asymptomatic with a progressive growth into the bone. Many of them are diagnosed by a routine radiological examination. Material and Methods This study reports a 12-year-old girl that presented an asymptomatic large radiolucent unilocular lesion associated to the crown of 3.8 that caused displacement of the molar and the inferior alveolar canal. Differential diagnosis included OKC, unicystic ameloblastoma, ameloblastic fibroma, dentigerous cyst and orthokeratinized odontogenic cyst. Two surgical interventions were performed; first, a marsupialization, and 10 months after, the third molar extraction plus cyst enucleation, mucosa excision and the application of Carnoy’s solution. Results The anatomopathological exam confirmed diagnosis of OKC. There was no evidence of recurrence after 2 years of follow-up. Conclusions Marsupialization followed by surgical enucleation with mucosa excision and Carnoy’s solution can help manage treatment of OKC, a lesion characterized by an aggressive behavior. Key words: Odontogenic keratocyst, mucosa excision, carnoy solution, third molar, tooth extraction.