Mandibular Ameloblastoma Research Articles

Identification of BRAF V600E mutation in odontogenic tumors by high-performance MALDI-TOF analysis

Odontogenic tumors are rare lesions with unknown etiopathogenesis. Most of them are benign, but local aggressiveness, infiltrative potential, and high recurrence rate characterize some entities. The MAP-kinase pathway activation can represent a primary critical event in odontogenic tumorigenesis. Especially, the BRAF V600E mutation has been involved in 80–90% of ameloblastic lesions, offering a biological rationale for developing new targeted therapies. The study aims to evaluate the BRAF V600E mutation in odontogenic lesions, comparing three different detection methods and focusing on the Sequenom MassARRAY System. 81 surgical samples of odontogenic lesions were subjected to immunohistochemical analysis, Sanger Sequencing, and Matrix-Assisted Laser Desorption/Ionization-Time of Flight mass spectrometry (Sequenom). The BRAF V600E mutation was revealed only in ameloblastoma samples. Moreover, the presence of BRAF V600E was significantly associated with the mandibular site (ρ = 0.627; P value <0.001) and the unicystic histotype (ρ = 0.299, P value <0.001). However, any significant difference of 10-years disease-free survival time was not revealed. Finally, Sequenom showed to be a 100% sensitive and 98.1% specific, suggesting its high-performance diagnostic accuracy. These results suggest the MAP-kinase pathway could contribute to ameloblastic tumorigenesis. Moreover, they could indicate the anatomical specificity of the driving mutations of mandibular ameloblastomas, providing a biological rational for developing new targeted therapies. Finally, the high diagnostic accuracy of Sequenom was confirmed.

Histological Pattern of Ameloblastoma in Affiliated Hospitals of Oral and Maxillofacial Surgery Department Faculty of Dental Medicine Airlangga University

Introduction: Ameloblastoma is a benign tumor. Clinically there are no distinct differences from the types of ameloblastoma. The correlation of clinical, radiological, and histological features is expected to provide a better understanding of this disease. This study to describe the distribution of the histopathological type of mandibular ameloblastoma in patients post mandibular resection. Methods: This study was a retrospective study with a descriptive method using total sampling of the medical records of mandibular ameloblastoma patients who had undergone mandibular resection and with viable postoperative histopathological data in the hospital network of the Department of Oral and Maxillofacial Surgery, Airlangga University, Surabaya in 2015-2019. Results: 22 data samples were obtained. The histolopathological examination of all subtypes, the most common type of pattern was 14 cases with mixed type histological patterns, the most common combination was follicular &amp; plexiform type in the third decade of life, and the single histology subtype most commonly found was the follicular type. No statistically significant differences were found between the histopathological subtypes, mixed type of ameloblastomas and the demographical and clinical parameters, but significant results were found between mixed type and tumor location Conclusion: The most common histologic type is mixed type with a combination of folicular and plexiform types, but it is recommended to use immunohistochemistry examination to provide a better understanding.

Assessment of Bone and Soft Tissue Margins in Resection of Mandibular Ameloblastoma: An Institutional Series

<h3>Introduction</h3> The treatment of gnathic ameloblastoma remains controversial. When resection is undertaken, a planned linear bone margin of at least 1.0 cm is often recommended for mandibular tumors. For cases in which tumor has extended beyond bone, inclusion of the adjacent anatomic barrier is recommended, however little attention has been devoted to the margin reporting of non-osseous margins. <h3>Materials and Methods</h3> Emory University records were searched for patients undergoing resection for ameloblastoma between 1/1/2020 and 3/01/2021. Twenty-one consecutive patients underwent surgical resection during the fourteen-month interval. In six cases, specimen fragmentation precluded margin evaluation. In three cases, only rare tumor islands remained microscopically in the resection specimen after initial biopsy inadvertently removed much of the lesion. The twelve remaining patients formed the study cohort. <h3>Results</h3> Patients ranged from 22 to 78 years of age, and 6 were male. Segmental mandibular resection was performed in 10 cases and marginal mandibular resection accomplished in 2. Average tumor size was 4.9 cm. In 10 of 12 cases, ameloblastoma extended beyond the mandibular bone. In all ten cases, the soft tissue margin was grossly identified as the margin nearest to tumor. Microscopically, soft tissue margin clearance measured 1.0 mm or less and in one, tumor involved the soft tissue margin. All bone margins measured 0.6 cm or greater from tumor, with 10 of 12 mandibular bone resection margins showing a linear distance of 1.0 cm or more from tumor. <h3>Conclusion</h3> In ameloblastoma perforating bone, soft tissue margins are most likely to represent the closest margin. Narrow clearance of soft tissue margins in ameloblastoma may be related to the lack of a specific guiding measurement in the literature. Close soft tissue margins can be identified grossly, and the clinical significance of ample bone margin clearance in the setting of narrow soft tissue clearance remains uncertain.

Fibular Free Flap and Iliac Crest Free Flap Mandibular Reconstruction In Patients With Mandibular Ameloblastomas.

Ameloblastoma (AM) is the most common, locally aggressive odontogenic tumor. It comprises about 1% of all head and neck neoplasms. It occurs mainly in young adults in their 3rd and 4th decade of life. It localizes in the mandible in about 80% of the cases. According to the 2017 WHO classification, 4 types of ameloblastoma can be distinguished: ameloblastoma (previously referred to as solid/multicystic-SMA; the "conventional type" AM), unicystic (AM-UA), extraosseous/peripheral (AM-PA), and malignant/metastatic (AM-MA). Solid, multicystic is the most common type. It is characteristic for its aggressiveness and high risk of recurrence. Radical resection with consecutive reconstruction is the treatment of choice of mandibular ameloblastomas.In this study, the authors present their experience in the surgical treatment of mandibular ameloblastomas with vascularized free flap reconstructions. They discuss new technological possibilities that could improve the precision of the reconstructive procedure and therefore result in the better aesthetic outcome.The retrospective study of a group of 21 patients suffering from mandibular ameloblastoma who underwent segmental man-dibulectomy with simultaneous microvascular free flap reconstruction was conducted. A thorough clinical analysis with various aspects was performed. Tumors resected before 2017 were double checked patomorphologically and assigned to the corrected subtype group.Seven patients were admitted to the department due to recurrent ameloblastoma. The most common localization of the tumor was the mandibular body ( n = 6) andbodywith ramus of the mandible ( n = 6). A total amount of 10 iliac crest free flaps and 12 fibular free flaps were performed. Complications were reported in 4 patients. A purulent oro-cutaneus fistula occurred in 3 patients. There was a flap failure in each reconstructive group. The virtual surgical planning with intraoperative cone-beam computed tomography was used in 3 patients. Dentition implantation was conducted in 4 patients (3 simultaneously, 1 postponed). The mean follow-up was 5 years and 8 months.Radical resection that covers radical segmental mandibulect-omy with immediate microvascular free flap reconstruction is a first-line and only effective treatment of mandibular ameloblas-tomas, that eliminates the risk of recurrence. The extent of surgical margins seems not to influence the recurrence rate, yet further investigation with statistical analysis should be performed. The choice of the adequate free flap must be adapted to dimensions and localization of the tumor and to each patient individually.New technologies such as virtual surgical planning with 3D models and intraoperative cone-beam computed tomography can make the reconstruction more accurate, improving patient's quality of life.

Genetic Study of BRAF V600E and SMO L412F Mutations in Japanese Patients with Ameloblastoma.

Background and aim. Ameloblastoma is a benign, intraosseous, progressively growing, epithelial, odontogenic neoplasm. BRAF and SMO mutations have been reported in ameloblastoma. In this study, we evaluated BRAF V600E and SMO L412F mutations; and assessed the relationship between BRAF V600E mutant expression and the clinicopathological features in Japanese patients with ameloblastoma. Methods. We examined 24 formalin-fixed paraffin-embedded samples. All specimens were from patients with mandibular ameloblastoma: 20 were conventional ameloblastoma and 4 were unicystic ameloblastoma. The BRAF V600E mutation was assessed by Sanger sequencing and immunohistochemistry, and the SMO L412F mutation was assessed only by Sanger sequencing. Results. Twenty of the 24 (83%) ameloblastoma samples carried the BRAF V600E mutation; 22 of the 24 (92%) samples were immunohistochemically positive for BRAF V600E. However, the SMO L412F mutation was not detected in any of them. The BRAF V600E mutation status did not correlate with the clinicopathological features, such as age, sex, location, method, recurrence, and subtype. Conclusion. BRAF inhibitors could be a potential treatment option for Japanese patients with ameloblastoma, harboring the BRAF V600E mutation.

Metástase pulmonar de ameloblastoma malígno: revisão e relato de caso

ABSTRACT Despite being a benign tumor of the maxillofacial region, some cases of ameloblastoma can be categorized as malignant ameloblastoma (or metastasizing) when metastases occur. The aim of this study is to report a rare case of lung metastasis from mandibular ameloblastoma, in order to review its risk and analyze the main anatomic sites that can occur with this disease. The case of a 48-year-old woman is described. She presented a metastatic pulmonary ameloblastoma 7 years after the removal of a mandibular ameloblastoma. During routine exams, a tumor in the left lung was observed. It was asymptomatic, near to the mediastinum, measured 7x5.5 cm. Transthoracic needle biopsy revealed ameloblastoma with the same histological characteristics of the primary tumor. After radiotherapy, the patient presented regression of the tumor. The patient has been under follow-up for 5 years and there is no presence of tumor. Ameloblastoma is an aggressive tumor not only in the region of origin, but also in distant regions, mainly in cases of recurrence. Metastases can cause high rates of morbidity, a fact that requires early treatment.

Minimally invasive approach in treatment of ameloblastoma in adolescent: 3-years follow-up

BackgroundTreatment of ameloblastoma in young patients should be conservative to avoid serious complications resulting from radical surgery. The aim of this study was to evaluate the prognosis of surgical excision with thorough curettage (peripheral ostectomy) in treatment of ameloblastoma in adolescent.Patients and methodsThis study included eight patients with mandibular ameloblastoma, which was confirmed by preoperative computed tomography and histopathological examination of incisional biopsy specimen and all patients were treated by surgical excision with thorough curettage.ResultsThis study involved six males and two females, with an age ranged from 12 to 16 years with a mean of age 13.75 years. All lesions occurred in the mandible. Recurrence was not observed in seven cases of eight cases after 36 months follow up and occurred only in case no 7.ConclusionAmeloblastoma in adolescents can be successfully treated conservatively by surgical excision with thorough curettage (peripheral ostectomy).

Challenges associated with the management of giant mandibular ameloblastoma in a resource-poor environment

Challenges associated with the management of giant mandibular ameloblastoma in a resource-poor environment

EMBOLIZATION IN RECURRENT SOFT TISSUE AMELOBLASTOMA EXCISION OF THE MANDIBLE

Background: Recurrent ameloblastoma can occur after radical treatment, 13.3% up to 19% involves soft tissue. Case of recurrent mandibular ameloblastoma in soft tissue, bleeding is one of the risks that often occurs. One way to reduce intraoperative bleeding is by embolization. Purpose this studi to report the benefits of embolization to reduce intraoperative bleeding in the action of recurrent ameloblastoma in soft tissue. Method: Female patient 32 years old came to RSUP Dr. Sardjito with complaint of lump on her left cheek, with history of post-hemimandibulectomy ameloblastoma 14 years ago. Objective examination of the asymmetrical patient's face with swelling extends to the cheek and pain when pressed, and the size is around 10x10 cm. Embolization using PVA and gelfoam material done before the excision of the tumor to reduce the risk of bleeding. The excision in this case is using lip split method, with bleeding during surgery around 250 ml. Biopsy results after excision are multicystic ameloblastoma, some are follicular types and some are plexiform types Conclusion: The use of embolization in the case of recurrent mandibular ameloblastoma in soft tissue can reduce tumor size and reduce bleeding during surgery.

Approach and conservative surgical treatment of jaw ameloblastoma: case report

Ameloblastoma is a benign neoplasm, originated from the odontogenic epithelium. It preferentially affects the mandible and due to its infiltrative growth pattern, it has a tendency to local recurrence. Treatment varies based on clinical, histological and radiographic characteristics. The aggressive treatment, such as marginal resection, has shown good results, however, it also has greater morbidity. Conservative treatments, such as decompression, enucleation and curettage, can also be used, with specific indications, and when carefully performed, it has a good prognosis. Thus, the objective of this work is to describe a case of mandibular ameloblastoma, treated in a more conservative way. Male patient, 53 years old, presented an increase in volume in the anterior region of the mandible. The clinical and radiographic characteristics suggested that it was a cystic lesion, so decompression and incisional biopsy were performed, the diagnosis of which was cystic ameloblastoma. The decompression device was maintained until bone neoformation was no longer observed, with conservative marginal resection being performed, followed by peripheral ostectomy.

The role of folded fibular flap in patients\u2019 reconstruction of mandibular defects: a retrospective clinical study

This study has analyzed 41 patients with mandibular ameloblastoma who underwent a partial mandibulectomy and reconstruction by folding the free fibular flap. In the preoperative and postoperative (6 months and 24 months after surgery), the Quality of Life (QOL) of these patients was assessed by using the University of Washington Quality of Life Questionnaire (UW-QOL) and the medical outcome study short form-36 (SF-36) questionnaires. SPSS 20.0 statistical software was used to conduct statistical analysis on the base data of the two groups of patients. Independent sample t test was conducted for sf-36 and UW-QOL scores at two time points in each group. The SF-36 survey showed that body pain (54.54 ± 8.10), general health (55.27 ± 7.54), and health changes (58.29 ± 9.60) decreased significantly at 6 months after surgery, but the mean score at 24 months after surgery all exceeded the preoperational level. At 24 months after the surgery, the vitality (80.41 ± 3.74), social function (81.61 ± 4.07), emotional role (82.39 ± 4.07), psychological health (81.66 ± 4.37) and total score (704.00 ± 31.53) all returned to the preoperative level, which was statistically significant compared with 6 months after surgery. However, there was no significant difference compared with the preoperative level. The UW-QOL survey showed that chewing (56.68 ± 7.23), speech (54.54 ± 7.7) and taste (62.29 ± 10.15) have significantly changed at 6 months after the surgery, and the difference was statistically significant at 24 months after surgery. Saliva generation decreased slightly (80.76 ± 3.35) at 6 months after surgery, but quickly returned to the preoperative level (81.59 ± 4.06). The total score of the patients almost recovered to the preoperative level at 24 months after surgery. The folded the fibular flap can not only repair the defects of soft tissue and bone tissue, but also restore the height of the alveolar ridge to, avoid the imbalance of crown and root ratio after implantation and reduce the occurrence of peri-implant inflammation, so that a true functional reconstruction can be realized.

Mandibular reconstruction with microvascularized graft after ameloblastoma resection: case series

Ameloblastoma is a locally aggressive and highly infiltrative tumor with a high recurrence rate. Its multicystic form the recommended treatment is resection with a safety margin, which results in significant facial defects with esthetic and functionals repercussions. Microvascular surgery revolutionized the reconstruction of significant defects because these grafting techniques allow a more satisfactory aesthetic and functional restoration. This study aimed to report a series of cases of reconstructions of mandibular defects using microvascularized fibular graft after ameloblastoma resection. Six patients were included in this study, and we collected data related to the surgical procedure, diagnosis, complications and follow-up. The patients were characterized as four women and two men, with a mean age of 23.8 years, with a diagnosis of mandibular ameloblastoma located mainly in the body, angle and mandibular ramus. These patients underwent lesion resection, resulting in defects larger than 5 cm, which justified using a microvascularized fibular graft for its reconstruction. The patients evolved well, with good results and without recurrences or complications in a postoperative follow-up of 2 to 5 years. Ameloblastoma is a lesion that reaches large dimensions and causes excellent cosmetic and functional damage. The microvascularized graft is an alternative in reconstructing significant defects and allows satisfactory morphofunctional reestablishment with minimal complications.

Ameloblastoma of the mandible in Anbar province. A prospective study

Objectives: The purpose of this study was to find out the incidence of histologic types of mandibular ameloblastoma in Anbar Province and its radiographic appearance in respect to age and site.Study design: Aprospective study was conducted in Anbar Province on 38 patients whose ages ranged from 18- 54 years (28 males and 10 females) with radiologically and histologically confirmed ameloblastoma of mandible from November 2008- August 2011. Patients were treated in Maxillofacial Surgery Department/ College of Dentistry/ Anbar University and Maxillofacial Unit of Ramadi Teaching Hospital. According to investigations, each type and location of the tumor was matched radiologically and histologically with age and site. All cases were surgically treated by resection of the mandible and enucleation of the tumor with or without bone graft. Results: Radiologically, 55% of casees presented as unilocular and 45% as multilocular. Histologically, cases appeared as follicular (37%) and plexiform (42%) in younger age groups, while in older patients they were acanthomatous (21%). Conclusion: Follicular and plexiform ameloblastomas occur in younger patients and more frequently in the posterior part of the jaws. In contrast, the acanthomatous ameloblastoma is found in older patients and frequently more anterior than other types.

Assessment of the quality of life of mandibular ameloblastoma patients after reconstruction with double-barrel fibula flap

Objective: To analyse the quality of life of patients receiving repair of bone defect with folded fibula flap after removal of mandibular ameloblastoma. Methods: The case data of 39 patients with ameloblastoma admitted to the First Affiliated Hospital of Zhengzhou University from August 2013 to April 2016 were retrospectively analysed, including 21 males and 18 females, from 18 to 58 years old. 3D printing and digital technology were used in flap preparation before surgery in all patients. The folded fibular flaps were used to repair mandibular defects and the implants were placed between 6-9 months after surgery. The short form-36 health survey questionnaire (SF-36) and the university of Washington quality of life questionnaire (UW-QOL) were applied to evaluate the quality of life of patients before surgery and at 6 months and 24 months after surgery. The higher the score, the better the condition. SPSS 20.0 was adopted for statistical analysis. Results: The SF-36 survey showed that the mean score of body role before surgery (72.4±11.7) was significantly higher than that at 6 months after surgery (39.6±11.1, t=23.580, P<0.05) or that at 24 months after surgery (59.8±6.4, t=8.358, P<0.001). Compared with the preoperative mean scores of Physical Pain (73.0±11.0), General Health (73.4±10.4) and Health Changes (79.2±3.9) before surgery, the mean scores Physical Pain (53.1±7.7), General Health (53.5±7.5) and Health Changes (63.9±11.7) at 6 months after surgery were decreased significantly respectively (t=13.068, 13.756 and 10.880, respectively, all P<0.05), but the mean scores Physical Pain (78.8±14.0), General Health (80.9±12.6) and Health Changes (84.4±4.6) at 24 months after surgery were increased significantly respectively (t=-2.904, -4.027 and -7.586, respectively, all P<0.05), with significant differences in the mean scores of Physical Pain, General Health and Health Changes between 6 and 24 months after surgery (t=-14.241, -16.490, -14.294, respectively, all P<0.001). The UW-QOL survey showed that the mean scores of chewing, language and taste functions decreased at 6 months after surgery (53.1±6.7, 53.0±7.7 and 62.2±9.9, respectively), but improved at 24 months after surgery (67.9±3.9, 63.9±2.9 and 68.4±11.1, respectively), with statistically significant difference (t=-16.765, -11.675 and 2.498, respectively, all P<0.001). Conclusion: The application of folded fibula flaps to repair bone defects after sugery of mandibular ameloblastoma can better meet the needs of language and chewing functions and improve the quality of life of patients.

Three-dimensional Printing Technology for Deep Circumflex Iliac Artery Flap: From Recipient to Donor Sites.

SummaryThe deep circumflex iliac artery (DCIA) flap is one of the most commonly used vascularized free flaps for jaw reconstruction; however, its clinical application is limited by donor site complications. We aimed to describe a new technique of using 3-dimensionally (3D) printed patient-specific devices for mandibular reconstruction with DCIA flap and simultaneous dental implants, and for donor site restoration after harvesting the DCIA flap. One patient with mandible ameloblastoma underwent mandibular reconstruction using a DCIA flap with the “jaw-in-a-day” approach. The 3D-printed patient-specific devices included mandibular cutting guides, DCIA harvesting and dental implant guide, surgical plate, and iliac prosthesis. The postoperative 1-month accuracy measurement showed the mean distance deviations of the mandible, transferred bone grafts, dental implants and iliac prosthesis were 1.8 mm, 2.1 mm, 0.9 mm, and 1.2 mm, respectively. Three-dimensionally printed iliac prosthesis satisfactorily restored the contour of the iliac crest after DCIA flap harvesting. No complication of donor site was recorded during the follow-up of 12 months. We successfully used 3D-printed patient-specific implants in both donor and recipient sites for DCIA flap jaw reconstruction. Further studies with a larger sample size and long-term follow-up are needed.

Treatment of a BRAF V600E Positive Ameloblastoma in a Pediatric Patient with MEK Inhibitor Monotherapy

Ameloblastomas are uncommon tumors of the odontogenic epithelium standardly treated with radical resection. Recent studies of the genetic landscape of ameloblastoma have revealed the frequent presence of the BRAF V600E mutation, suggesting a possible role for targeted chemotherapy. We present the case of a primary mandibular ameloblastoma found in a 13-year-old female with confirmed BRAF V600E mutation. Prior to invasive surgical intervention she was treated for 8 weeks with the MEK inhibitor trametinib, but her tumor demonstrated little radiographic, clinical, or histologic response. Previous case reports have shown ameloblastoma in adult patients to be responsive to other agents targeting the MAPK pathway. Our observations in the presented case demonstrate the need for further research into the utility of targeted chemotherapy in ameloblastoma treatment.

A Long-Standing Giant Mandibular Ameloblastoma and its Management with Microvascular Free Fibular Graft: a Case Report.

Ameloblastoma is one of the most common benign epithelial odontogenic tumors of jaws. We report a case of long-standing slow-growing giant ameloblastoma involving almost all of mandibular bone. The solid multicystic lesion was excised, and the histopathological examination showed the follicular type of ameloblastoma. Furthermore, the defect was reconstructed with microvascular osteocutaneous free fibular graft.

Mandibular ameloblastoma treated by hemimandibulectomy and immediate free fibula flap reconstruction - a multidisciplinary approach: case report

Ameloblastoma is a benign epithelial odontogenic tumor that presents locally invasive behavior associated with high recurrence rates. This case report aims to describe and illustrate the treatment of an extensive mandibular ameloblastoma. A 23-year-old male patient affected by ameloblastoma in the left jaw, complaining of edema in the region, dysphagia, and limitation of cervical movements. Presence of clinically visible ulcerated mass involving the teeth. Computed tomography showed an intraosseous, hypodense, expansive, multiloculated lesion. Left hemimandibulectomy was performed, followed by immediate free fibula flap reconstruction. Mandibular reconstruction with free flaps is an excellent modality to treat extensive multicystic ameloblastoma.

Whole exome sequencing and system biology analysis support the "two-hit" mechanism in the onset of Ameloblastoma.

Background Ameloblastoma is the most frequent odontogenic tumor. Various evidence has highlighted the role of somatic mutations, including recurrent mutation BRAF V600E, in the tumorigenesis of Ameloblastoma, but the intact genetic pathology remains unknown. Material and Methods We sequenced the whole exome of both tumor tissue and healthy bone tissue from four mandibular ameloblastoma patients. The identified somatic mutations were integrated into Weighted Gene Co-expression Network Analysis on publicly available expression data of odontoblast, ameloblast, and Ameloblastoma. Results We identified a total of 70 rare and severe somatic mutations. We found BRAF V600E on all four patients, supporting previous discovery. HSAP4 was also hit by two missense mutations on two different patients. By applying Weighted Gene Co-expression Network Analysis on expression data of odontoblast, ameloblast, and Ameloblastoma, we found a proliferation-associated gene module that was significantly disrupted in tumor tissues. Each patient carried at least two rare, severe somatic mutations affecting genes within this module, including HSPA4, GNAS, CLTC, NES, and KMT2D. All these mutations had a ratio of variant-support reads lower than BRAF V600E, indicating that they occurred later than BRAF V600E. Conclusions We suggest that a severe somatic mutation on the gene network of cell proliferation other than BRAF V600E, namely second hit, may contribute to the tumorigenesis of Ameloblastoma. Key words:Ameloblastoma, whole exome sequencing, somatic mutation, BRAF, HSPA4, two-hit theory.

BRAF V600E mutation-specific immunohistochemical analysis in ameloblastomas: a 44-patient cohort study from a single institution.

The aim of this study is to investigate the presence and prevalence of BRAF V600E mutation in ameloblastomas using anti-BRAF V600E monoclonal antibody (VE1 clone) and to identify any clinicopathologic correlation with BRAF V600E mutation in ameloblastoma. The pathology files of the Department of Oral Pathology and Oral Medicine, Faculty of Dentistry, Lagos State University College of Medicine, Lagos, Nigeria, were searched for the diagnosis of ameloblastoma from 2016 to 2020. Archived non-decalcified formalin-fixed paraffin-embedded tissue underwent immunohistochemistry using anti-BRAF V600E antibody at the University of Pittsburgh, Pennsylvania. Clinicopathologic data such as age at diagnosis, gender, jaw bone involved (mandible or maxilla), tumor location (anterior or posterior) and histologic subtype were collected. The clinicopathologic parameters were analyzed using Chi-square test and Fisher's exact test according to the BRAF status. Forty-four cases of ameloblastoma were retrieved. The male to female ratio was 1.32:1. The average age of patients at diagnosis was 33.3years. Thirty-nine cases were located in the mandible and 5 cases in the maxilla. Only cases in the mandible were positive for anti-BRAF V600E antibody (n = 15/39; 38.5%). There was a significant correlation between BRAF V600E expression in mandibular tumors and histologic subtype (p = 0.02); however, no significance was observed for gender, age and tumor location. BRAF V600E mutation preferentially occurs in mandibular ameloblastomas, especially in non-plexiform ameloblastomas. These patients may benefit therapeutically from the use of BRAF inhibitors.