Ameloblastoma: a retrospective single institute study of 34 subjects

Implant-supported prosthetic rehabilitation after Ameloblastomas treatment: a systematic review

BACKGROUND

Ameloblastoma (AM), the benign counterpart of ameloblastic carcinoma, is a benign odontogenic tumor of epithelial origin, naturally aggressive, with unlimited growth potential and a high tendency to relapse if not adequately removed. Patients with AM treated surgically can benefit from dental implant therapy, promoting oral rehabilitation and improving their quality of life. The present study aimed to determine the survival rate of dental implants placed after surgical treatment of patients affected by AM. In addition, there were two secondary objectives: 1) To evaluate which dental implant loading protocols are most frequently used and 2) To determine the type of prosthetic restoration most commonly used in these patients.

METHODS

The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were followed during the study. Searches were performed in three databases (PubMed/MEDLINE, Scopus, and Google Scholar) until November 2023. Additionally, the electronic search was enriched by an iterative hand search of journals related to oral pathology and medicine, maxillofacial surgery, and oral prosthodontics and implantology. Only reports and case series in English from January 2003 to date were included. The Joanna Briggs Institute tool (JBI-Case Reports/Case Series) was used for the study quality assessment.

RESULTS

The total number of patients and implants studied were 64 and 271, respectively, all with surgically treated AM. The patient's ages ranged from 8 to 79 years, with a mean (SD) age of 37.3 ± 16.4. Fifty-three percent were male and 47% were female. The range of follow-up duration was 1 to 22 years. An implant survival/success rate of 98.1% was reported. In addition, most of them were conventionally loaded (38.3%). Hybrid implant-supported fixed dentures were the most commonly used by prosthodontists (53%).

CONCLUSIONS

Oral rehabilitation with dental implants inserted in free flaps for orofacial reconstruction in surgically treated patients with AM can be considered a safe and successful treatment modality.

A Systematic Review of Adenoid Ameloblastoma: A Newly Recognized Entity

BACKGROUND

Recently, a new odontogenic tumor has been described, the so-called adenoid ameloblastoma (AdAM). The aim of this review was to determine the clinical and imaging features of AdAM and to describe its main histopathological findings.

METHODS

The systematic review included published cases with a diagnosis of AdAM in the gnathic bones, which had sufficient clinical, imaging, and histopathological data to confirm its diagnosis. The following histopathological diagnostic criteria were adopted: presence of ameloblastoma-like components, duct-like structures, spiral cellular condensations, and a cribriform architecture.

RESULTS

Fifteen articles, corresponding to 30 cases of AdAM, were selected. Most cases affected men (63.3%), with a slight preference for the mandible (16:14) and the posterior region of gnathic bones was the most commonly affected site. The mean age at diagnosis was 40.8 years. Clinically, the lesions usually presented as a swelling (53.3%) and, radiographically, as a well-defined radiolucency (33.4%). Surgical resection (40%) was the most frequently adopted treatment and recurrence occurred in 30% of cases. Microscopic examination showed cribriform areas in most AdAM cases (93.3%); duct-like structures and spiral cellular condensations were seen in 100% of the cases.

CONCLUSION

The small number of reported cases, the existence of erroneous diagnoses, and the adoption of initial conservative management make it difficult to determine whether AdAM has a higher risk of recurrence or more aggressive biological behavior than conventional ameloblastomas.

Carbon ion radiotherapy for recurrent ameloblastoma: A case report

Ameloblastoma is a kind of benign, odontogenic tumor of epithelial origin, and surgery is mainstay treatment method; however, recurrence is common, and usually the treatment for recurrence is still surgery. We report on a patient of recurrent ameloblastoma treated with carbon ion radiation therapy and achieved a good efficacy. A 25-year-old female with relapse of an ameloblastoma was referred to the Wuwei Heavy Ion Center for carbon ion therapy. She had been initially diagnosed with ameloblastoma 8 years ago and underwent operation of right mandible ameloblastoma. After she transferred to our center, she accepted a dose of 60 GyE carbon ion radiation therapy, and the efficacy is good. Carbon ion radiation therapy can be an effective treatment option for ameloblastoma.

MMP-7, -8, -9, E-cadherin, and beta-catenin expression in 34 ameloblastoma cases

Objectives

Ameloblastoma is a benign, locally aggressive odontogenic tumor with high recurrence rates. Matrix metalloproteinases (MMPs) mediate extracellular integrity in normal and pathological conditions, and exert multiple functions coordinating inflammation and tumor progression. E‐cadherin and beta‐catenin are adherence junction molecules in cell‐to‐cell connections. We investigated the involvement of MMP‐7, ‐8, ‐9, E‐cadherin, and beta‐catenin in ameloblastoma and the surrounding extracellular matrix.

Material and methods

Our material consisted of 30–34 tissue samples from ameloblastoma patients of Helsinki University Hospital. We used immunohistochemistry to detect the expression of the biomarkers. Two oral pathologists independently scored the immunoexpression intensities and statistical calculations were made based on the results.

Results

E‐cadherin expression was weaker in the maxillary than in mandibular ameloblastomas. Beta‐catenin was expressed in the ameloblastoma cell membranes. We detected MMP‐8 and ‐9 expression in polymorphonuclear neutrophils in the extracellular area and these MMPs correlated positively with each other. Osteoclasts lining bone margins and multinuclear giant cells expressed MMP‐9. Neither MMP‐8 nor MMP‐9 immunoexpression could be detected in ameloblastoma cells. MMP‐7 expression was seen in some apoptotic cells.

Conclusion

The fact that E‐cadherin immunoexpression was weaker in maxillary compared to mandibular ameloblastomas might associate to earlier recurrences. It promotes the idea of mandibular and maxillary ameloblastoma exerting differences in their biologies. We detected MMP‐8 and ‐9 in polymorphonuclear neutrophils which relates to these MMPs participating in extracellular remodeling through a mild inflammatory process. Bone degradation around ameloblastoma may be due to MMP‐9 in osteoclasts but this phenomenon might be an independent process and needs further investigations.

BRAF V600E expression in ameloblastomas-A 36-patient cohort from Helsinki University Hospital

OBJECTIVES

We aimed to investigate BRAF V600E percentage immunohistochemically in ameloblastomas of a single institute cohort. We were interested if age, location, histological properties, or tumor recurrence depend on the BRAF status.

SUBJECTS, MATERIALS AND METHODS

We had 36 formalin-fixed, paraffin-embedded ameloblastoma tissue samples of patients treated at the Helsinki University Hospital between the years 1983-2016. Tissue sections underwent immunohistochemistry by Ventana BenchMark XT immunostainer using Ms Anti-Braf V600E (VE1) MAB. We used R 3.4.2 and RStudio 1.1.383 to conduct statistical analysis for BRAF positivity and earlier onset as well as tumor location. We used chi-squared tests and 2-by-2 table functions to determine connections between BRAF positivity and recurrence, growth pattern, and type.

RESULTS

BRAF-positive tumors occurred in younger patients compared to BRAF-negative tumors (p = 0.015) and they located mostly to the mandible (p < 0.001). Growth patterns were limited to two in BRAF-negative tumors when BRAF-positive tumors presented with one to four growth patterns (p = 0.02). None of the maxillary tumors showed BRAF positivity and of these, 72.2% recurred.

CONCLUSIONS

An immunohistochemical BRAF marker could be a beneficial tool to predict the outcome of patients with this aggressive, easily recurring tumor.