Ameloblastoma: demographic data and treatment outcomes from Melbourne, Australia

Surgical Resection and Reconstruction of Ameloblastoma: A 13-Year Retrospective Review

BACKGROUND

Ameloblastoma is a locally aggressive, benign tumor presenting in the maxilla and mandible prone to recurrence. Resection greatly limits recurrence; however, reconstruction becomes critical to preserve patients' functionality and esthetics.

PURPOSE

The aim of this study was to describe surgical resection and reconstructive approaches in the treatment of ameloblastoma and compare clinical outcomes to conservative methods of treatment.

STUDY DESIGN, SETTING, SAMPLE

A retrospective case series was completed through analysis of patient records. The study population was composed of patients treated for ameloblastoma at the Royal Brisbane Hospital (Queensland, Australia) in the Oral and Maxillofacial Surgery Unit from January 1, 2008, to December 31, 2020. Patients without histological confirmation of intraosseous ameloblastoma were excluded from the study sample.

PREDICTOR VARIABLE

Not applicable.

MAIN OUTCOME VARIABLE(S)

The primary outcome variable was time to recurrence. Secondary outcome variables included any surgical complications incurred.

COVARIATES

The covariate variables collected included age at diagnosis/treatment, gender, ethnicity, location of lesion and site(s) of involvement, tumor extent, alveolar expansion, histopathological growth pattern, and soft tissue involvement.

ANALYSES

Descriptive statistics were computed for each study variable.

RESULTS

A total of 48 cases of histologically confirmed ameloblastoma were identified (41 mandibular, 7 maxillary) involving 50 excisional operations (44 resections, 6 enucleations). Of these cases, 44 were followed up > 12 months, with a mean length of follow-up time of 65.6 months. No recurrence was detected for resected lesions. One enucleated lesion recurred at 25 months. Thirty-seven reconstructive procedures were undertaken, including 32 immediate free flaps. All reconstructive flaps and grafts survived, and no major complications were recorded.

CONCLUSION AND RELEVANCE

Resection of ameloblastoma limits recurrence and should be considered curative. Immediate microvascular free flap reconstruction of maxillary and mandibular defects from resection of ameloblastoma is safe and predictable.

The 'D-M-C' strategy for conventional ameloblastoma of the mandible: a retrospective study

The purpose of this multicentre study was to evaluate the efficacy of the 'dredging-marsupialization-curettage' (D-M-C) strategy in the treatment of conventional intraosseous ameloblastoma of the mandible. A total of 31 patients from three institutions, who had a pathological diagnosis of conventional ameloblastoma of the mandible, were treated with the D-M-C strategy. The surgical protocol comprised a dredging and marsupialization (D-M) step, with additional D-M steps as required. The patients then underwent curettage (C) once an obvious effect of the D-M step had been achieved during follow-up. Eight patients were followed up for ≥36 months but <60 months, while 23 were followed up for ≥60 months. Nineteen of the 23 patients followed up for ≥60 months were disease-free at the last follow-up, with no evidence of recurrence. The D-M step is effective for reducing the tumour size and preserving vital structures. The D-M-C surgical strategy may be a feasible treatment option for conventional ameloblastoma of the mandible.

Giant Mandibular Ameloblastoma with Rare Hypercalcemia: A Case Report and Literature Review

Ameloblastoma is the most common benign odontogenic tumor with local invasion and high recurrence, which generally occurs in the jaw bones. Hypercalcemia is a common paraneoplastic syndrome that is commonly observed in patients with malignancies but rarely encountered in patients with benign tumors. Thus far, not many cases of ameloblastoma with hypercalcemia have been reported, and the pathogenic mechanism has not been studied in depth. This paper presents a case report of a 26-year-old male diagnosed with giant ameloblastoma of the mandible, accompanied by rare hypercalcemia. Additionally, a review of the relevant literature is conducted. This patient initially underwent marsupialization, yet this treatment was not effective, which indicated that the selection of the appropriate operation is of prime importance for improving the prognosis of patients with ameloblastoma. The tumor not only failed to shrink but gradually increased in size, accompanied by multiple complications including hypercalcemia, renal dysfunction, anemia, and cachexia. Due to the contradiction between the necessity of tumor resection and the patient's poor systemic condition, we implemented a multi-disciplinary team (MDT) meeting to better evaluate this patient's condition and design an individualized treatment strategy. The patient subsequently received a variety of interventions to improve the general conditions until he could tolerate surgery, and finally underwent the successful resection of giant ameloblastoma and reconstruction with vascularized fibular flap. No tumor recurrence or distance metastasis was observed during 5 years of follow-up. Additionally, the absence of hypercalcemia recurrence was also noted.

Hemimaxillectomy defect reconstruction with a maxillary obturator prosthesis using a 3D-model stereolithography: A case report

INTRODUCTION

Complete or partial resection of the maxilla during tumor surgery causes oronasal defects, leading to oral-maxillofacial dysfunction, for which the obturator prosthesis is an important treatment option. Traditional manufacturing of obturators involves great complexity, often results in impaired function and fit, and is time-consuming. This paper presents a case of using 3D stereolithography as a guide design for defect reconstruction with a maxillary obturator prosthesis.

CASE PRESENTATION

We report a 14-year-old girl who presented with facial deformities followed by swelling and pain that reached the orbit floor on the left side of her face. A non-contrast head magnetic resonance imaging scan showed a mass in the left maxilla that extended from the buccal mandible to the left side of the oral cavity. An incisional biopsy indicated that the mass was an ameloblastic fibroma. The entire tumor was treated with a hemi-maxillectomy and reconstruction using an obturator. No further complaints or recurrence signs were evident after six months.

DISCUSSION

Treatment options for ameloblastoma include enucleation and excision. Due to the severity of the lesion in our case, the entire maxilla had to be removed with the tumor, using a hemimaxillectomy with the assistance of a 3D-printed model, and an obturator was used for reconstruction.

CONCLUSION

Ameloblastoma is a tumor with a high risk of recurrence. This case underwent a complete hemi-maxillectomy with simultaneous repair using a 3D-printed obturator, with satisfactory functional and cosmetic outcomes.

Recurrent Ameloblastoma: Clinical Manifestation and Disease-Free Survival Rate

Objectives

Ameloblastoma is a slow-growing epithelial odontogenic neoplasm of the jaws with a high recurrence rate. The main treatment strategies for this lesion are radical or conservative surgical approaches. The aim of the present study was to analyze clinical presentations, histological types, and treatment strategies of recurrent ameloblastoma and to define its disease-free survival (DFS) rate.

Materials and Methods

Twenty-four cases of recurrent ameloblastomas, treated between January 2009 and July 2021, were enrolled in this study. Medical files from each patient, including gender, age, size of the lesion, localization, patient complaints, clinical manifestation, radiographic appearance, histological type, surgical management, and treatment results were reviewed and analyzed retrospectively.

Result

Out of 69 operated primary ameloblastomas, the rate of recurrence was 35%. Out of 24 recurrent cases, 21 developed after conservative treatment and 3 after radical treatment. In most cases, recurrences were found in the mandible (n = 20). A unilocular pattern was predominant in radiographic examination (44%). Estimated 3-year DFS was 84.5 ± 4.8%, and the 5-year and 10-year DFS were 73.0 ± 6.3% and 43.9 ± 8.343.9 ± 8.3%, respectively.

Conclusion

Results obtained in the present retrospective study proved the necessity of long-term follow-up after both conservative and radical treatment approaches. The DFS median in our study was 8 years (95% CI 6 years–10 years). For recurrent cases, radical resection with histologically free margins after exact MRI determination of the ameloblastoma border within the soft tissues should be considered as the method of choice to avoid secondary recurrence.

Ameloblastomas vs recurrent ameloblastomas: a systematic review

Introduction: Ameloblastoma is an odontogenic tumour with high recurrence rate. The objective of the present study was to evaluate existing literature regarding clinical, radiographic, histopathologic features, treatment, and recurrence rate of ameloblastomas and compare it with features of recurrent ameloblastomas. Materials and methods: A systematic review was done based on the PRISMA statement. Search was performed in “Pubmed” database with search terminology “recurrent ameloblastoma”, “ameloblastoma recurrence” for articles published between 2010 and 2020. Data were extracted from full‐text articles and discussed. Results: Out of 515 articles, 16 articles fulfilled the inclusion and exclusion criteria. Data was analysed in two sections. The first with 10 publications assessed features of ameloblastoma in general and their recurrence rate while the second section evaluated features of only recurrent ameloblastomas in 6 publications. There were 234 recurrences in 936 cases with recurrence rate of 23.50%. Male predominance was noted and mandible was commonly affected. Solid/multicystic ameloblastomas formed 74.5% of the tumours and unicystic formed 23.3%. The recurrence rate after conservative treatment was 64.9% and after radical treatment was 12%. Conclusions: The main factors for recurrence were multilocular ameloblastomas, follicular histopathology and conservative treatment.

Recurrence Rates of Intraosseous Ameloblastoma Cases With Conservative or Aggressive Treatment: A Systematic Review and Meta-Analysis

Objective

This study aimed to systematically investigate and compare the post-treatment recurrence of intraosseous ameloblastoma in patients treated with conservative or aggressive approaches.

Methods

Systemic searches of PubMed, Medline, Cochrane Library, and Embase databases from inception to October 28, 2020, were conducted. Studies that aimed to evaluate the recurrence of intraosseous ameloblastoma by conservative and aggressive treatment approaches were included.

Results

A total of 20 studies with 942 ameloblastoma cases were included. Fourteen studies included patients with ameloblastoma who received conservative treatment, and 16 studies reported the overall recurrence rate for patients undergoing aggressive treatment. The pooled results indicated that the recurrence rate for aggressive treatment [0.12, 95% confidence interval (CI) = 0.09–0.16] was significantly lower than that for conservative treatment, with a recurrence rate of 0.30 (95% CI = 0.23–0.39). Similar results were obtained when stratifying the participants by the histological classification. When trying stratification analysis following the original included studies, multicystic ameloblastoma presented a much higher recurrence rate than solid and unicystic ameloblastomas.

Conclusion

These findings supported the hypothesis that aggressive treatment might lead to a lower recurrence rate than conservative treatment. More studies and meta-analyses following the new histological classification of ameloblastomas are needed to validate and support the findings.

Controversies in ameloblastoma management: evaluation of decision making, based on a retrospective analysis

BACKGROUND

The ameloblastoma management is still challenging to the high recurrence rates and significant morbidity associated with radical treatment. The purpose of this 10-year retrospective study was to analyze the influence of ameloblastoma type and treatment strategy on the long-term outcomes and recurrence rates.

MATERIAL AND METHODS

The retrospective analyses of 64 histologically-confirmed ameloblastoma cases was performed. The possible risk factors for recurrence and the development of complications were estimated statistically.

RESULTS

The treatment strategy applied for this group of patients was the following: thirty-four patients (53.1%) were treated conservatively with enucleation or extended bone curettage. Radical treatment (bone resection) was applied in 30 (46.9%) cases. The follow-up period ranged from 2 to 10 years (mean value 4.28 ± 3,26). General recurrence rate consisted 32.8%. This study did not find significant correlations between clinical or histopathological features of the ameloblastoma and the recurrence rate. The only factor that significantly influence recurrence rate was the treatment strategy (41% in conservative treatment vs 15% in radical treatment, p<0.05). Postoperative complications were observed in 42 patients (65.6%) and included face asymmetry and disfigurement (17.2%), temporary paresthesia of the inferior alveolar nerve (IAN) - 23.4%, permanent paresthesia of IAN - 20.3%, paresis of a marginal branch of the facial nerve - 6.3%, infection 12.5%, and swelling - 20.3%. The complication rates, esthetic and functional deficiency were significantly higher in radically treated patients (p<0.05) Conclusions: Our study confirms that higher recurrence rate is associated with conservative treatment for ameloblastoma, while radical treatment leads to an increased number of postoperative complications that affect the patient's quality of life.

Presentation, Diagnostic Imaging, and Clinical Outcome of Conventional Ameloblastoma in Dogs

A noninductive tumor of odontogenic epithelium occurs within the tooth bearing regions of the jaw in dogs and fits the conventional definition of ameloblastoma, which is distinct from, and less common than, canine acanthomatous ameloblastoma. In order to clarify the clinical and radiological features of this uncommon odontogenic tumor in dogs, we performed a retrospective study of 20 dogs that were diagnosed between 2007 and 2015. Follow-up information was obtained for 17 of 20 dogs. The study group of dogs showed no apparent age, breed, or gender predilection. Conventional ameloblastoma is typically slow growing, well demarcated, and locally destructive. Tumors most commonly occurred as a mass or focal bony swelling within the maxilla (13/20) or mandible (7/20). Based on cases with available diagnostic imaging, as either dental radiographs or computed tomographic images, the tumors were usually intraosseous and caused mixed lytic/proliferative bone changes. Nevertheless, conventional ameloblastomas did not aggressively infiltrate adjacent tissues and recurrence was not observed within the study group, even in patients with narrow surgical margins or treatment by cyst enucleation.

Synchronous occurrence of odontogenic keratocyst and ameloblastoma: A case report and review of the literature

Odontogenic keratocyst (OKC) and ameloblastomas are distinct histopathologically diagnosed odontogenic lesions of the oral cavity. Both are primarily located in the posterior regions of the mandible, however, they can involve the maxilla as well. The occurrence of both an OKC and ameloblastoma in a patient is very uncommon. This case demonstrated such a lesion in the mandible of a 57 years old female. The diagnostic work-up and features of both lesions are illustrated with special focus on histopathological variances distinguishing OKC from ameloblastoma with the support of immunohistochemistry. This case highlights the importance of identifying accurate diagnoses for such lesions which may prompt clinical implications. Clinico-pathologic understanding of both lesions signifies the need for careful management plan and prevention of recurrence. Previously reported simultaneous occurrences of odontogenic cysts and/or tumors in the oral cavity are also reviewed.

A geographical analysis of ethnic distribution of jaw ameloblastoma in Nigerians

Introduction

Ameloblastoma is the most common odontogenic tumour in Nigeria. A definite geographic variation has been observed in the frequency of odontogenic tumors from different parts of the world. However, there is no study on the regional variations in Nigeria. Hence, this study was designed to document the ethnic and geographical distribution of jaw ameloblastoma in Nigeria.

Methods

Archival data on ameloblastoma from 10 health facilities were obtained. Global Moran's I detected geographic clustering in its distribution while Local Getis Ord indicated the location of ameloblastoma clusters. Chi-square tested associations between variables at 0.05 level of significance.

Results

A total of 1,246 ameloblastoma cases were recorded in Nigeria. Besides substantial state variations, a South-North gradient was noticed in its distribution. Significant positive spatial autocorrelation was observed in the three major groups while ameloblastoma hotspots were found in the SouthWestern and Northwestern Nigeria. The Igbos had a higher prevalence of ameloblastoma outside their home region than within.

Conclusion

The study hypothesized that the geographical distribution of ameloblastoma in Nigeria is the result of all or one of the following: the country's tropical climate, migration patterns and health seeking behavior. Hopefully, these claims should lead to further enquiry on the underlying causes.

Global incidence and profile of ameloblastoma: A systematic review and meta-analysis

OBJECTIVES

To evaluate the global incidence of ameloblastoma and to provide a profile of ameloblastoma patients.

MATERIAL AND METHODS

A systematic review and meta-analysis was conducted. Searches were performed in PubMed, EMBASE, SCOPUS, and Web of Science for articles published from 1969 to 2018 for the global incidence and from 1995 to 2018 for the profile of ameloblastoma patients.

RESULTS

Seven studies on the incidence rate of ameloblastoma were included in the meta-analysis. These studies only covered Europe, Africa, and Australia. The pooled incidence rate was 0.92 per million person-years (95% CI: 0.57-1.49), with significant heterogeneity between studies. Forty-two articles provided profile data of 6,446 ameloblastoma patients. Mean age was 34 years and the peak age incidence in the third decade of life. In Europe and North America, ameloblastoma mostly occurred at an older age when compared to Africa and South America. A slight male preference (53%) was found, and the mandible appeared to be the preferred site. The most common type of ameloblastoma was multicystic. The histopathologic patterns were mostly follicular and plexiform.

CONCLUSIONS

This is the first study assessing the global incidence of ameloblastoma. The pooled incidence rate was determined to be 0.92 per million person-years.

Radical vs conservative treatment of intraosseous ameloblastoma: Systematic review and meta-analysis

OBJECTIVES

The aim of the present study was to assess the outcomes of radical and conservative treatment approaches of solid/multicystic and unicystic ameloblastoma in terms of recurrence rates.

MATERIAL AND METHODS

A systematic review and meta-analysis was conducted based on the PRISMA statement. Search was performed using PubMed, Embase, SCOPUS, and Web of Science for articles published from January 1969 until March 2018. Quality assessment of the selected articles was conducted using the Quality Appraisal of Case Series Studies Checklist. The meta-analysis was performed using the MedCalc program.

RESULTS

The search strategy yielded 6,984 articles; 20 studies met the eligibility criteria and were included in the meta-analysis. The pooled recurrence rate of solid/multicystic ameloblastomas following radical treatment was 8%, while conservative treatment caused recurrences in 41%. For unicystic ameloblastomas, these values were 3% and 21%, respectively. The risk of recurrences in both types of ameloblastomas following radical treatment was lower than following conservative treatment.

CONCLUSIONS

The present study showed statistically significant differences in recurrence favoring radical treatment for both unicystic and solid/multicystic ameloblastoma. The solid/multicystic type showed more recurrences than the unicystic type. Unfortunately, since only retrospective studies were available, the evidence is less strong as wished for.

Is conservative surgery a better choice for the solid/multicystic ameloblastoma than radical surgery regarding recurrence? A systematic review

PURPOSE

Determine if conservative surgery of primary solid/multicystic ameloblastoma (SMA) is capable of decreasing the recurrence rate as effectively as radical surgery.

METHODS

We searched in MEDLINE, Web of Science, Scopus and Cochrane Library for original studies reporting on the conservative or radical treatment of primary SMA and the related recurrence rate. All selected data were independently assessed. Meta-analysis was performed and the Relative Risk (RR) of recurrence with a confidence interval of 95% was the effect measure. P value for the summary effect of < 0.05 was considered statistically significant.

RESULTS

The 2647 records retrieved were reduced to 7 studies to be qualitatively assessed and 4 studies were included in the meta-analysis. RR of 1.88 [0.59, 5.95] of the pooled values pointed that recurrence rate after the conservative surgery is neither comparable nor lower than the radical surgery (P = 0.28).

CONCLUSIONS

Conservative surgery does not reduce the recurrence rate as efficiently as radical surgery for primary SMA. However, there is not enough evidence to support this statement.

The Epidemiology, treatment, and complication of ameloblastoma in East-Indonesia: 6 years retrospective study

Background

Ameloblastoma is a neoplasm classified as a benign epithelial odontogenic tumor of the jaws, grow slowly and are locally invasive. The aim of the present study was to investigate the incidence, treatment, and complication of patients with ameloblastoma in East-Indonesia during six years retrospective study.

Material and Methods

This retrospective study included 84 patients who were diagnosed with ameloblastoma from 2011 to 2016. There were 56 patients with treatment data available. Data from each patient, including gender, age, histologic type, the size of the tumor, radiologic form, tumor location, type of treatment, and complication were reviewed and analyzed retrospectively.

Results

Fourteen patients were diagnosed with unicystic ameloblastoma (25%), thirty two patients with multicystic follicular ameloblastoma (57%) and ten patients with an unspecified multicystic ameloblastoma (18%). A total of about 35 patients were treated conservatively (62.5%) and 21 patients were treated radically (37.5%). Swelling was present as a pre-operative complication in all 56 cases (100%). There were no complaints concerning speech.

Conclusions

The majority findings of the histologic type were multicystic ameloblastoma and their location were in the mandible. Most ameloblastoma were treated conservatively and reconstructions were made with only titanium plates and not bone graft.

Key words:Ameloblastoma, epidemiology, east Indonesia.