Surgical management of ameloblastoma in children

Treatment of benign maxillomandibular osteolytic lesions larger than 4 centimeters: a systematic review

OBJECTIVE

. This systematic review aimed to assess the different treatments of benign maxillo-mandibular radiolucent bone lesions over 4 centimeters to propose a management algorithm.

STUDY DESIGN

A literature search was conducted using MEDLINE/PubMed, Scopus, Google Scholar, Virtual Health Library databases, and gray literature. Randomized or non-randomized clinical trials and case series with 10 or more patients with a minimum follow up of 1 year, published in French or English until August 2023, were included. The risk of bias was assessed for all papers included.

RESULTS

Of 1433 records identified, 22 were included in this review, reporting data from 1364 lesions. Ameloblastoma was the most common lesion (51.22%) and mandible was the most common site (81.21%). Initial conservative treatment was prevalent (71.04%). Recurrence was higher after conservative (13.8%) than after radical treatments (6.5%). Multilocularity, cortical perforation, dental element preservation were linked to a higher recurrence risk.

CONCLUSION

This study has shown importance of understanding specific characteristics and recurrence risk in benign maxillomandibular osteolytic lesions. Multidisciplinary team approval, personalized approach based on lesion type and patient are crucial. The presence of at least one risk factor could lead to therapeutic decision. Despite limitations, the study informed lesion management and provided precise recommendations.

Unicystic ameloblastoma appeared as a massive multilocular entity: A case report with long-term follow-up

INTRODUCTION

Unicystic ameloblastomas are a rare variant of ameloblastomas, which are characterized by slow growth and being relatively locally aggressive, with the main site of origin being the posterior portion of the mandible, it also refers to those cystic lesions that show clinical, radiographic, or gross features of a jaw cyst.

PRESENTATION OF CASE

A 27-year-old female patient presented with a chief complaint of extensive mass of mandible along with severe swelling and numbness of right lips and chin. The oral examination revealed a swelling in the molar region of the right mandible with buccal plate expansion. The radiographic and histopathologic features were consistent with the diagnosis of unicystic ameloblastoma. Consequently, the lesion was surgically removed, and no clinical or radiological recurrence was detected during 5 years post-operative follow-up.

DISCUSSION

While previous reports of unicystic ameloblastoma in the posterior portion of the jaw showed favorable prognosis lesions appeared as a unilocular entity, this case reports multilocular appearance and aggressive behavior of expansive unicystic ameloblastoma. Furthermore, while some studies linked the unilocular appearance of unicystic ameloblastoma to impacted tooth, our case suggests a possible traumatic link of preexisting lesion into multilocular unicystic ameloblastoma related to impacted tooth.

CONCLUSIONS

This case presents a rare multilocular unicystic ameloblastoma appearance, notably with impacted tooth involvement. It also indicates the potential transformation of solid ameloblastoma into unicystic ameloblastom.

Curettage combined with decompression for the treatment of ameloblastoma in children: report of two cases

BACKGROUND

Ameloblastoma (AM) is the most common benign odontogenic tumor, which is more often detected in the mandible than maxilla, especially the mandibular body and mandibular angle. Pediatric AM is a rare disease, especially in patients aged 10 and younger. Compared with the mainstream osteotomy and reconstructive surgery for adult ameloblastoma, there is more room for discussion in the treatment of pediatric ameloblastoma. The postoperative functional and psychological influence can not be ignored. Especially for children in the period of growth and development, an osteotomy is often challenging to be accepted by their parents. We report two patients with ameloblastoma under 10 years old who are treated with curettage and fenestration, which is a beneficial method for children with ameloblastoma.

CASE PRESENTATION

We present two cases of classic ameloblastoma in children. We describe in detail the patients' characteristics, treatment processes, and follow-up result. The bone formation and reconstruction in the lesion area after fenestration decompression and curettage are recorded at every clinic review. The surgical details and principles of curettage and decompression are also described and discussed. The two patients have good bone shape recovery and no recurrence.

CONCLUSIONS

Children are in the growth and development period and possess an extremely strong ability of bone formation and reconstruction. Based on the principles of minimally invasive and functional preservation, we believe that curettage combined with decompression can be the first choice for treating AM in children, especially for mandibular lesions.

A review of oral pathology in orthodontics. Part 2: Pathology of the jaw bones

For many patients, their first full jaw imagining will be requested and reported by an orthodontist. This may lead to the discovery of unexpected pathology in the jaws. In this review article, we discuss the clinical and radiological appearance as well as the pathologic features and treatment of the more common entities of the jaws. In addition, we will discuss the less common lesions which carry important consequences for the patient. Through the identification of these lesions, appropriate referral and management can be pursued.

Machine learning-based radiomics for predicting BRAF-V600E mutations in ameloblastoma

Background

Ameloblastoma is a locally invasive and aggressive epithelial odontogenic neoplasm. The BRAF-V600E gene mutation is a prevalent genetic alteration found in this tumor and is considered to have a crucial role in its pathogenesis. The objective of this study is to develop and validate a radiomics-based machine learning method for the identification of BRAF-V600E gene mutations in ameloblastoma patients.

Methods

In this retrospective study, data from 103 patients diagnosed with ameloblastoma who underwent BRAF-V600E mutation testing were collected. Of these patients, 72 were included in the training cohort, while 31 were included in the validation cohort. To address class imbalance, synthetic minority over-sampling technique (SMOTE) is applied in our study. Radiomics features were extracted from preprocessed CT images, and the most relevant features, including both radiomics and clinical data, were selected for analysis. Machine learning methods were utilized to construct models. The performance of these models in distinguishing between patients with and without BRAF-V600E gene mutations was evaluated using the receiver operating characteristic (ROC) curve.

Results

When the analysis was based on radiomics signature, Random Forest performed better than the others, with the area under the ROC curve (AUC) of 0.87 (95%CI, 0.68-1.00). The performance of XGBoost model is slightly lower than that of Random Forest, and its AUC is 0.83 (95% CI, 0.60-1.00). The nomogram evident that among younger women, the affected region primarily lies within the mandible, and patients with larger tumor diameters exhibit a heightened risk. Additionally, patients with higher radiomics signature scores are more susceptible to the BRAF-V600E gene mutations.

Conclusions

Our study presents a comprehensive radiomics-based machine learning model using five different methods to accurately detect BRAF-V600E gene mutations in patients diagnosed with ameloblastoma. The Random Forest model's high predictive performance, with AUC of 0.87, demonstrates its potential for facilitating a convenient and cost-effective way of identifying patients with the mutation without the need for invasive tumor sampling for molecular testing. This non-invasive approach has the potential to guide preoperative or postoperative drug treatment for affected individuals, thereby improving outcomes.

A network meta-analysis assessing the effectiveness of various radical and conservative surgical approaches regarding recurrence in treating solid/multicystic ameloblastomas

Multiple treatment approaches have been undertaken to reduce the incidence of recurrence in solid/multicystic ameloblastoma (SMA), both conservative and radical. A network meta-analysis (NMA) was conducted to assess and compare the effectiveness of these various treatment approaches concurrently. This study was reported based on the Preferred Reporting Items for Systematic Reviews for Network Meta-Analysis (PRISMA-NMA) statement. PubMed (MEDLINE), ScienceDirect, Scopus, and Web of Science were searched until August 10, 2021. The NMA was conducted using the STATA program. Of 1153 records identified in the search, seven observational studies with 180 patients were included. Six different treatment approaches were identified. Segmental resection ranked highest for reducing the recurrence rate with the highest SUCRA score (77.7), followed by curettage with cryotherapy (66.9) and marginal resection (49.3). Network inconsistencies and publication bias appeared to be absent. According to the Confidence in Network Meta-Analysis (CINeMa) method, the evidence's certainty was low for all comparisons due to imprecision and within-study bias. In conclusion, this study is the first NMA in the field of ameloblastoma. Segmental resection seemed to be the most effective treatment approach for minimizing recurrence in SMA patients. Nevertheless, weak certainty of evidence makes that the results must be regarded with caution.

Analysis of intraoral microvascular anastomosis in maxillofacial defects reconstruction

This review summarizes the research progress in the field of intraoral microvascular anastomosis techniques (IAT) and attempts to investigate the indications for procedures in which IAT can be applied, the surgical procedure and the difficulties involved, technical assessments, result evaluation and the perspective. Currently, microvascular anastomosis technique is widely used in maxillofacial defects reconstruction from various causes including cutaneous injury or congenital deformity which usually required extensive flap reconstruction and therefore a vascular free flap is routinely used. Conventional microvascular anastomosis reconstruction techniques cannot avoid new incisions, which will affect the postoperative aesthetic situation. Surgeons have therefore attempted to improve this technique to effectively eliminate scars caused by surgery: some patients can be chosen to undergo microvascular anastomosis of the free flap intraorally, thus reducing the extraoral incision caused by the anastomosis located in neck or maxillofacial improving the postoperative appearance of the patients. In addition to preserving the external appearance, intraoral anastomosis technique (IAT) can also solve some other problems of maxillofacial vascular anastomosis, such as insufficient vessel pedicle length and high risk of facial nerve injury.

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

ABSTRACT

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 mandibulectomy 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) and body with 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 3patients. 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 mandibulectomy with immediate microvascular free flap reconstruction is a first-line and only effective treatment of mandibular ameloblastomas, 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 intraoperativecone-beam computed tomography can make the reconstruction more accurate, improving patient's quality of life.

Effectiveness of the Conservative Surgical Management of the Ameloblastomas: A Cross-Sectional Study

Ameloblastoma is a benign, but locally aggressive odontogenic neoplasm, whose appropriate therapeutic management remains highly debatable. The aim of this study was to evaluate the reliability and effectiveness of the two conservative surgical therapeutic protocols (curettage with peripheral ostectomy only and curettage plus cryotherapy) for the management of ameloblastomas. About 53 cases of the ameloblastomas treated in 9 years were retrospectively analyzed regarding their clinical, histopathologic, radiographic, and therapeutic data. The results and the postoperative complications related to both the therapeutic protocols were also statistically investigated. A slight female preponderance was seen (1.12:1.0) with a mean age of 27.1 years. The posterior mandible was the most affected site and dental involvement was frequently found. Multilocular lesions causing the alterations of the bone cortices were the most common radiographic findings. Recurrences were seen in 9.4% of the cases and although the patients submitted to curettage plus cryotherapy have shown an increased incidence of wound dehiscence, infection, and paresthesia, only bone sequestration proved to be significantly more frequent in this group compared to the patients treated by curettage with peripheral ostectomy only. The incidence of the recurrences following the conservative management is low and cryotherapy use as an adjuvant tool must be rationally considered.

Unicystic Ameloblastoma of Mandible- Imaging Features: A Case Report and Literature Review

Ameloblastoma are benign tumors whose importance lies in its potential to grow into enormous size with resulting bone deformity. They are typically classified as unicystic, multicystic, peripheral, and malignant subtypes. Unicystic ameloblastoma (UA) refers to those cystic lesions that show clinical, radiographic, or gross features of an odontogenic cyst but on histological examination show a typical ameloblastomatous epithelium lining, with or without luminal and/or mural tumor growth. We present a very rare case of unicystic ameloblastoma in a girl child with an age of 10 years; clinical and radiographic features of UCA, its differential diagnosis, histopathology, and current concepts of management have also been discussed in the present paper.

Ameloblastoma of the jaws in children: an evaluation of cases seen in a tertiary hospital in South-Eastern Nigeria

Background

Ameloblastoma is one of the most common benign odontogenic tumours in Nigeria. It is considered uncommon in children.

Materials and methods

This is a retrospective study of pediatric patients with histopathological diagnosis of ameloblastoma seen over seven years at the Oral and Maxillofacial Surgery Department of the University of Nigeria Teaching Hospital, Enugu, Nigeria. Relevant information was retrieved from patients' records and data obtained were analysed using SPSS version 23, the chi-square test was used to compare qualitative variables, a p-value of <0.05 was considered as significant.

Results

One hundred and thirty-six cases of ameloblastoma in all age groups were seen within the period. Thirty of the cases met the requirement. The mean age of the patients was 14.4 STD 2.03 (range from 10–17) years. Fourteen (46.7%) patients were male while 16 (53.3%) were female giving a ratio of 1:1.1. The duration of the lesion ranged from 3 months to 72 months (mean 15.07 months). Histologically, the follicular type (n=20, 66.7%) constitute the majority, while the clinical types were solid-multicystic (n=18, 60%) and unicystic (n=12, 40%). Enucleation was the treatment of choice in most (n=18, (60%)) of the patients.

Conclusion

Ameloblastoma is relatively uncommon in children, especially those less than ten years of age. The solid-multicystic variety was the predominant type in the children studied. Most patients presented long after the onset of the tumour and enucleation with mechanical curettage produced satisfactory results in these patients.

Funding

None declared

Directions of mandibular canal displacement in ameloblastoma: A computed tomography mirrored-method analysis

Purpose

This study was performed to investigate mandibular canal displacement in patients with ameloblastoma using a 3-dimensional mirrored-model analysis.

Materials and Methods

The sample consisted of computed tomographic scans of patients with ameloblastoma (n=10) and healthy controls (n=20). The amount of mandibular canal asymmetry was recorded as a continuous variable, while the buccolingual (yaw) and supero-inferior (pitch) directions of displacement were classified as categorical variables. The t-test for independent samples and the Fisher exact test were used to compare groups in terms of differences between sides and the presence of asymmetric inclinations, respectively (P<0.05).

Results

The length of the mandibular canal was similar on both sides in both groups. The ameloblastoma group presented more lateral (2.40±4.16 mm) and inferior (−1.97±1.92 mm) positions of the mental foramen, and a more buccal (1.09±2.75 mm) position of the middle canal point on the lesion side. Displacement of the mandibular canal tended to be found in the anterior region in patients with ameloblastoma, occurring toward the buccal and inferior directions in 60% and 70% of ameloblastoma patients, respectively.

Conclusion

Mandibular canal displacement due to ameloblastoma could be detected by this superimposed mirrored method, and displacement was more prevalent toward the inferior and buccal directions. This displacement affected the mental foramen position, but did not lead to a change in the length of the mandibular canal. The control group presented no mandibular canal displacement.

Conservative management with Carnoy's solution in ameloblastoma involving two unerupted teeth: a report of two cases

Marsupialization is widely used as a primary treatment modality for reducing size of large cysts. However, there is no recommendation for specific duration of marsupialization. In addition, Carnoy’s solution usually is applied at the time of enucleation as a fixative agent. In this report, we present an appropriate marsupialization duration of ameloblastoma involving two unerupted teeth. In this present study, marsupialization using a Foley catheter was performed in two cases of ameloblastoma of the mandible involving two adjacent impacted teeth. Carnoy’s solution was applied for 3-5 minutes after enucleation in both patients. Periodically during marsupialization, the size of the radiolucency was measured in panoramic view, and clinical examination was performed. No remarkable paresthesia or soft tissue injury was observed after application of Carnoy’s solution or during follow-up. We recommend 12 to 16 weeks as an adequate marsupialization duration for a large ameloblastoma involving two impacted teeth based on increased radiopacity along the margins of the lesions. Poor oral hygiene was an issue after 12 weeks of marsupialization in one case. There were no remarkable complications with Carnoy’s solution in either case. The Foley tube has a two-way system that is more effective for irrigating the cavity than is the conventional one-way system.

Influence of biodegradable polymer membrane on new bone formation and biodegradation of biphasic bone substitutes: an animal mandibular defect model study

Purpose

The purpose of this study was to evaluate the influence of biodegradable polycaprolactone membrane on new bone formation and the biodegradation of biphasic alloplastic bone substitutes using animal models.

Materials and methods

In this study, bony defect was formed at the canine mandible of 8 mm in diameter, and the defects were filled with Osteon II. The experimental groups were covered with Osteoguide as barrier membrane, and the control groups were closed without membrane coverage. The proportion of new bone and residual bone graft material was measured histologically and histomorphometrically at postoperative 4 and 8 weeks.

Results

At 4 weeks, the new bone proportion was similar between the groups. The proportion of remaining graft volume was 27.58 ± 6.26 and 20.01 ± 4.68% on control and experimental groups, respectively (P < 0.05). There was no significant difference between the two groups in new bone formation and the amount of residual bone graft material at 8 weeks.

Conclusion

The biopolymer membrane contributes to early biodegradation of biphasic bone substitutes in the jaw defect but it does not affect the bone formation capacity of the bone graft.

Maxillary ameloblastoma in an 8-year-old child: A case report with a review of the literature

Ameloblastoma is a benign locally invasive tumor with a high tendency to recur. It is considered rare in the pediatric population, with most cases diagnosed in the third to fifth decades of life. Approximately 80% of ameloblastomas occur in the molar and ramus region of the mandible, while 20% of cases occur in the maxillary posterior region. This report presents a case of plexiform ameloblastoma in an uncommon location in an 8-year-old child. The lesion was initially thought to be a dentigerous cyst, based on its location and radiographic appearance. The clinical and radiographic features, histopathology, and treatment of solid, plexiform, maxillary ameloblastoma are reviewed, with an added emphasis on a literature review of ameloblastoma in children. This report emphasize the importance of long-term follow-up, since recurrence may occur many years after initial tumor removal.

Conservative management is effective in unicystic ameloblastoma occurring from the neonatal period: A case report and a literature review

Unicystic ameloblastoma (UA), a benign odontogenic tumor of the jaw, represents less than a third of all ameloblastomas and seems less aggressive than other types of ameloblastoma. We present here the first case of UA that developed prenatally and was successfully managed in the early neonatal period with marsupialization and curettage performed carefully to avoid injury to the tooth germ. BRAF and SMO mutations were not detected. After 2 years of follow-up, complete reossification and normal eruption of deciduous teeth were noted, and there was no recurrence of UA. We recommend conservative treatment of UA in the pediatric population to avoid loss of and/or injury to the tooth germ, provided close follow-up is carried out all through the individual's growth for early detection of potential recurrences, growth impairments, or tooth eruption disorders. The intratumoral somatic mutational status of BRAF, SMO, RAS family, and FGFR2 may help determine personalized targeted treatment, particularly in case of recurrence.

The Changing Landscape in Treatment of Cystic Lesions of the Jaws

Objective:

Cystic lesions of the jaw are common pathologies of chronic swelling of the jaw in oral and maxillofacial regions. Different treatment modalities have been described in the literature. However, the existence and proper treatment of these cysts remains a contentious topic. The aims of this review were to discuss the complexity of various surgical treatment and as factors with potential to influence outcome treatment. Finally, a practical and a rational clinical guideline for the management of such lesions have been suggested.

Materials and Methods:

A literature search without language limitation was performed in 2018 using MEDLINE, PubMed, Scopus, and Embase. Keywords for the search included the following terms: jaws cyst, cystic lesions, odontogenic cysts, cystic tumors, pseudocysts, treatments, therapy, wound healing, bone regeneration, and teeth involved cysts. Prospective or retrospective clinical studies with a sample size of n ≥ 5 were evaluated and included in this review. The exclusion criteria were studies with unclear reporting of the treatment applied or outcome, nonhuman studies, case reports, letters, preface, comments, and cystic lesions associated to syndrome. After the full reading, 30 articles were included in the quantitative synthesis for the review. No meta-analysis could be performed due to the heterogeneity of the studies included. Clinical radiographic images were presented to illustrate the principles of some surgical treatments.

Conclusion:

Conservative surgery with primary closure defect (less than 4 cm) remains an initial approach, which reduces the morbidity of aggressive surgeries and obtains the complete bone healing before 24 months of postoperative. Marsupialization is considered as the most common option for the treatment of large cystic lesions when cases are carefully selected. Evocyst is an attractive new technique of obtaining complete bone defect healing within <3 months.

Cysts and tumors of the jaws treated by marsupialization: A description of 4 clinical cases

Since the 4th edition of the World Health Organization’s Classification of Head and Neck Tumours was published in January of 2017, the keratocystic odontogenic tumor is back into the cyst category as odontogenic keratocyst (OKC). Depending on the size of the cyst, its location and the patients’ age, several treatment options are available: curettage, enucleation, radical treatment and marsupialization. The marsupialization is a conservative technique used in early tumor stages, as curative treatment for the odontogenic cyst. Despite its disadvantages and controversies, the marsupialization remains an interesting therapeutic choice in the case of large cysts, or in very young or old patients. We describe, in this article, four clinical cases of odontogenic cysts. We report the surgical management and the subsequent evolution of the patients. The discussion focuses on the indications, advantages and limitations of the odontogenic cyst’s marsupialization. We review the specific conditions of the odontogenic cysts that could make the marsupialization the optimal therapeutic option. In our cases, the marsupialization proved to be a conservative technique which allowed the respect of neighboring anatomical structures, particularly in the case of large cysts, but requires prolonged clinical and radiological monitoring. Pathological entity for our cases was different. Thus, the treatment outcome may be different too. This series is very small and the reader should be cautious about drawing broad conclusions regarding the optimal therapeutic choice.

Key words:Marsupialization, odontogenic cyst.

Unicystic Ameloblastoma in a Child Treated with a Combination of Conservative Surgery and Orthodontic Treatment: A Case Report

Unicystic ameloblastoma (UAM) is a variant of intraosseous ameloblastoma that occurs as a single cystic cavity. This report describes a case of UAM of the mandible in a seven-year-old girl. The lesion radiographically mimicked a dentigerous cyst. Under the primary diagnosis of a dentigerous cyst, marsupialization was performed to erupt the first molar involved in the cystic lesion and to obtain a definitive diagnosis. The biopsy specimen revealed ameloblastoma. During careful observation, orthodontic treatment, which was performed to upright and promote the eruption of the first molar involved in the tumor, maintained the space needed for enucleation of the tumor. Finally, the second primary molar was extracted, and the lesion was enucleated at 3 years and 4 months after marsupialization. The results of the histological examination revealed UAM. Conclusively, the treatment course not only avoids a resection of the mandible but also induces eruption of the teeth involved in the tumor. Thus, the combination of conservative surgery and orthodontic treatment was effective in the management of UAM that mimics a dentigerous cyst.

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.

Successful conservative treatment of a mandibular unicystic ameloblastoma: 13-year follow-up

Ameloblastoma is an uncommon, locally aggressive benign odontogenic tumor and can reach considerable dimensions causing facial deformity and functional impairment. They are characterized by local aggressiveness. It is recommended that maxillary ameloblastomas be treated aggressively due to proximity of various vital structures. Conservative treatments such as marsupialization, enucleation and curettage while preserving bone integrity seem to be associated with a high rate of recurrence. Treatment evaluation of ameloblastomas is a complex issue, as ideally it should not be so destructive due to the benign nature of this lesion, but should be extensive enough to avoid recurrences. The present study is about a clinical case of a 16-year- old man with a unicystic ameloblastoma treated successfully with marsupialization. Patient was followed up every 12 months. About 13 years after diagnosis, the patient is clinically healthy and radiographically it is possible to observe evidence of bone repair.

Key words:Odontogenic tumors, ameloblastoma, marsupialization, unicystic.

Maxillary ameloblastoma: results of the treatment in 11 patients

Introduction: Surgery of maxilla ameloblastoma is mutilating and the tumor propensity for recurrence high. Patients and Methods: The oral and visual functions, facial morphology and tumor recurrence in 11 patients after maxillary ameloblastoma surgery are retrospectively reviewed. Results: Facial morphology was satisfactory in 7 patients who had all tumor removal by a type 1 or 2A maxillectomy and surgical wound closure. Out of these patients, 4 who had dental rehabilitation by conventional prosthesis presented satisfactory mastication. Four patients subjected to the tumor removal by a type 3 maxillectomy had all facial asymmetry. Out of these, 1 patient who did not have the orbital floor defect repair presented diplopia and enophtalmos, 2 patients subjected to the palate defect repair by a prosthetic obturator or oral mucosa had elocution impairment. The tumor recurrence occurred in 2 patients after tumor enucleation and in 1 patient after radical surgery out of 8 patients who had a postoperative follow-up. Discussion: In ameloblastoma surgery, achieving both the tumor recurrence prevention and a satisfactory facial reconstruction is challenging. Conclusion: Avoiding the tumor recurrence should be the major goal when patient post-surgical follow-up cannot be guaranteed.

Fibroblasts promote the collective invasion of ameloblastoma tumor cells in a 3D coculture model

Ameloblastoma is a benign tumor of the odontogenic epithelium with several histological subtypes. All subtypes of ameloblastoma contain abundant stroma; the tumor cells invade collectively into the surrounding tissues without losing intratumor cell attachments. However, the molecular mechanisms mediating ameloblastoma invasion remain unclear. Here, we evaluated the functional significance of the interactions between ameloblastoma tumor cells and stromal fibroblasts on collective cellular invasion using a three-dimensional cultivation method, double-layered collagen gel hemisphere (DL-CGH) culture. The AM-1 plexiform and AM-3 follicular human ameloblastoma cell lines and HFF-2 human fibroblasts were labeled with GFP and DsRed, respectively. Collective cellular invasion of ameloblastoma cells was assessed in the presence or absence of fibroblasts. Notably, without fibroblasts, AM-1 cells formed sharp, plexiform-like invasive processes, whereas AM-3 cells formed a series of blunt processes often observed during collective migration. In comparison, under the cocultures with HFF-2 fibroblasts, AM-3 cells formed tuft-like invasive processes and collectively invaded into outer layer more than that observed with AM-1 cells. Moreover, HFF-2 fibroblasts localized to the tips of the invasive tumor processes. These findings suggest that tumor-associated cells assist tumor cell invasion. Microscopic analysis of sectioned three-dimensional cultures revealed that AM-3/HFF-2 hemispheres were histologically similar to follicular ameloblastoma tumor samples. Therefore, our findings suggest that ameloblastoma subtypes exhibit distinct invasion patterns and that fibroblasts promote collective tumor invasion in follicular ameloblastoma.

Ameloblastoma: A retrospective analysis of 31 cases

Aims and objective

To evaluate the surgical treatment given and do a regular follow up to study the recurrence rate and complications of ameloblastoma in our institution.

Materials and methods

A total of 31 cases of various subtypes of ameloblastoma, treated with different modalities, in the Department of OMFS, were recalled for a follow up & radiographs were taken along with the clinical examination for any recurrence or complications such as fracture/exposure of the reconstruction plate, loosening of the screw, infection of the graft, any draining sinus/signs of infection.

Results

Two of our patients had fractured reconstruction plate, one patient developed infection, one patient complained of screw exposure and two other patients had infection of the iliac graft.

Conclusion

We conclude that an adequate resection with a safe margin could be a treatment option and can be undertaken depending on the extent, location of the lesion and histopathologic variant.

Recurrence and cancerization of ameloblastoma: multivariate analysis of 87 recurrent craniofacial ameloblastoma to assess risk factors associated with early recurrence and secondary ameloblastic carcinoma

OBJECTIVE

The recurrence and progression of ameloblastoma are unpredictable. Therefore, we examined the influence of clinical factors on recurrence time and analyzed the clinical factors associated with early recurrence and cancerization. We then developed a staging system to predict early recurrence and cancerization.

METHODS

All of the primary craniofacial ameloblastoma patients treated in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine were recorded. There were 87 recurrent cases used to create a staging system and tested in a Cox regression analysis for risk factors associated with early recurrence or cancerization following surgery.

RESULTS

There were 890 craniofacial ameloblastoma patients, and 72 cases had recurrence. There were also 15 cases with cancerous recurrence. The overall recurrence rate was 9.78%, and the cancer rate was 1.69%. The primary cases were classified into the following 3 stages based on clinicopathological features: stage I, the maximum tumor diameter ≤6 cm; stage II, the maximum diameter of tumor >6 cm or tumor invasion to the maxilla sinus/orbital floor/soft tissue; and stage III, tumor invasion of the skull base or metastasis into regional lymph nodes. When the method of surgery was controlled by partial correlation, the staging had significance with recurrence time (P=0.004). The Cox analysis showed the tumor stage was correlated with recurrence time (P=0.027) and cancerization time (P=0.002). However, the surgical method did not influence the recurrence time when adjusted for cofounding variables.

CONCLUSIONS

Tumor larger than 6 cm and invasion to soft tissues or adjacent anatomical structures are associated with early recurrence. This staging system can be used to predict the risk factors of early recurrence and cancerization in ameloblastoma patients.

Ameloblastoma: current etiopathological concepts and management

Ameloblastoma is a benign odontogenic tumor of epithelial origin. It is locally aggressive with unlimited growth capacity and has a high potential for malignant transformation as well as metastasis. Ameloblastoma has no established preventive measures although majority of patients are between ages 30 and 60 years. Molecular and genetic factors that promote oncogenic transformation of odontogenic epithelium to ameloblastoma are strongly linked to dysregulation of multiple genes associated with mitogen-activated protein kinase, sonic hedgehog, and WNT/β-catenin signaling pathways. Treatment of ameloblastoma is focused on surgical resection with a wide margin of normal tissue because of its high propensity for locoregional invasion; but this is often associated with significant patient morbidity. The relatively high recurrence rate of ameloblastoma is influenced by the type of molecular etiological factors, the management approach, and how early the patient presents for treatment. It is expected that further elucidation of molecular factors that orchestrate pathogenesis and recurrence of ameloblastoma will lead to new diagnostic markers and targeted drug therapies for ameloblastoma.

Conservative Management of Unicystic Ameloblastoma in Young Patients: A Prospective Single-Center Trial and Review of Literature

AIMS

The study intends to evaluate the clinical outcome of treating young patients of unicystic ameloblastoma, by various conservative treatment modalities such as marsupialization, enucleation with bone curettage and aid in establishing sound treatment guidelines.

MATERIALS AND METHODS

A case series of fifteen patients is presented of unicystic ameloblastoma, who presented to our Department over the past 6 years (2010-2015) and conservative method of treatment elected in all the patients. Also, a methodical literature review of studies discussing treatment of unicystic ameloblastoma in young age group (<20 years) patients over the last 15 years from 2001 to 2015 is added.

RESULTS

Faster osseous regeneration after conservative treatment was noted, owing to the young age and growth potential. Over a mean follow-up of 4 years, uneventful secondary healing, no clinical or radiographic evidence of recurrence and no apparent deformity were noted in any of the cases.

CONCLUSION

Unicystic ameloblastoma is a benign, locally invasive odontogenic neoplasm of young age which can develop during the stage of tooth formation and hence its early inception and vast proliferation is not uncommon in this age group, due to which it can grow into a huge lesion causing significant morbidity. Conservative surgical management may be a viable option to reduce morbidity and increase the probability of uneventful secondary healing and bone regeneration in the younger population.

Immunohistochemical Detection of p75 Neurotrophin Receptor (p75-NTR) in Follicular and Plexiform Ameloblastoma

INTRODUCTION

Ameloblastoma holds a unique position among benign tumours by its locally destructive and invasive nature. Recently improvised molecular techniques helped researchers to unravel the myth behind such biologic behaviour. Though interesting findings have been delivered, the rhythmic correlation regarding the exact mechanism still remains lacking. Neurotrophins and their receptor mediated pathways play a crucial role in survival, death and differentiation of many neuroectoderm derived cells. With this background, the study has been aimed to investigate the expression of p75-NTR (Neurotrophin Receptor) in follicular and plexiform ameloblastoma.

AIM

To analyze the immunohistochemical expression pattern of p75-NTR in ameloblastoma and to compare the immunohistochemical expression pattern of p75-NTR among the histological types of ameloblastoma, follicular and plexiform patterns.

MATERIALS AND METHODS

Total 22 ameloblastomas (12 follicular, 10 plexiform) were immuno-stained with anti-human p75-NTR mouse IgG monoclonal antibody and the pattern of staining is statistically analyzed.

RESULTS

Only 11 (10 follicular, 1 plexiform) out of 22 ameloblastomas showed immuno-reactivity to p75-NTR. In ameloblastoma, only the peripheral pre-ameloblast like tall columnar cells showed reactivity whereas the stellate reticulum-like cells were immuno-negative. The staining pattern was membranous in the immuno-reactive cells. The results were studied with the downstream pathways from the literature and a possible mechanism has been proposed.

CONCLUSION

The expression pattern of p75-NTR was found to be more in follicular ameloblastoma than plexiform.

Recurrent giant mandibular ameloblastoma in young adults

BACKGROUND

The purpose of the study was to define the most appropriate management of the giant mandibular ameloblastoma (GMA) in young adults.

METHODS

A retrospective study was performed on patients with GMA <30 years old. The data collected included initial treatment, tumor margins, reconstruction, and follow-up. Patients evaluated speech, chewing, swallowing, and facial appearance after definitive treatment.

RESULTS

Thirteen patients were identified with recurrent solid/multicystic disease requiring further treatment. Definitive treatment involved segmental mandibulectomy and reconstruction with free fibular flap in all patients. Seven patients had immediate reconstruction (group A) and 6 had secondary (group B). Mandibular resection was planned at least 2 cm beyond the radiological limit, free margins were achieved in all patients, and all flaps were transplanted successfully. In group A, functional score was 13.7 ± 0.45 and facial appearance score was 4.5 ± 0.49, whereas in group B were 11.16 ± 0.37 and 3.3 ± 0.5, respectively (both p < .05).

CONCLUSION

Aggressive resection of the GMA and immediate reconstruction is strongly advised. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1947-E1954, 2016.

Decompression of Odontogenic Cystic Lesions: Past, Present, and Future

Tumors and cystic lesions of the jawbones have been described since the late 1600s and it took another 200 years for classification systems to appear in the medical, surgical, and dental literatures. In the late 1800s, Carl Partsch introduced cystostomy, a method by which the cyst is converted into a pouch by suturing its lining to the mucosa of the oral cavity. The purpose of this article is to analyze the history, present, and future of cystic conditions of the jaws and decompression, a modality of treatment that during the past few years has regained the attention of oral and maxillofacial surgeons and pathologists owing to its relative simplicity and effectiveness compared with other conservative options.

Unicystic ameloblastoma with mural proliferation: conservative or surgical approach?

Ameloblastoma occurs in a wide variety of forms. Various forms of ameloblastomas have various treatment modalities ranging from a conservative approach to surgical resection with reconstruction. We report a case of unicystic ameloblastoma with mural proliferation in a 17-year-old girl, who presented with a swelling in the lower left jaw associated with dull aching pain and was managed initially by a conservative approach followed by surgical enucleation on recurrence.

Assessment of quality of life in giant ameloblastoma adolescent patients who have had mandible defects reconstructed with a free fibula flap

Background

The reconstruction of mandibular defects after giant ameloblastoma resection is one of the most challenging problems facing reconstructive surgeons. Mandibular resection has been associated with a poor quality of life (QOL), particularly in adolescent patients reconstructed with a free fibula flap. This study aims to evaluate QOL outcomes in adolescent patients who have had mandibular resections of giant ameloblastoma and reconstruction with a free fibula flap and to collect information about their socio-cultural situation.

Methods

The present study assessed 45 adolescent patients who had undergone immediate mandible reconstruction with a free fibula flap for faint ameloblastoma using University of Washington Quality of Life (UW-QOL) and 14-item Oral Health Impact Profile (OHIP-14) questionnaires.

Results

Thirty-five of the 54 questionnaires were returned (64.81%). In the UW-QOL, of the twelve disease-specific domains, the best three scores from the patients related to pain, shoulder and appearance and the worst three scores related to chewing, anxiety and saliva. In the OHIP-14, the lowest-scoring domain was handicap, followed by physical pain and social disability.

Conclusions

Mandibular reconstruction with a free fibular flap significantly influenced the adolescent patients’ QOL. Adolescent patients pay more attention to postoperative facial appearance; this should be considered in surgical planning.

Enucleation combined with peripheral ostectomy: its role in the management of large cystic ameloblastomas of the mandible

AIM

Aggressive resection of a large mandibular cystic ameloblastoma may cause severe deformity and dysfunction, while simple enucleation may carry a high risk of recurrence. The purpose of this study was to evaluate, in terms of both recurrence and the preservation of contour and function, the effectiveness of enucleation combined with peripheral ostectomy (Enu/PO) in managing large mandibular cystic ameloblastomas.

MATERIALS AND METHODS

Fourteen patients who had large mandibular cystic ameloblastoma (11 unicystic, 3 multicystic) and had been treated with the Enu/PO were reviewed.

RESULTS

The follow-up period was 19-117 months. Using Enu/PO, mandibular continuity was preserved in all patients, and only one patient complained of permanent lip numbness. With bone regeneration, the thinned bone plate significantly thickened and the residual cavity shrank. No pathological fracture occurred. There was recurrence in 3 patients. Two recurrences were treated with radical surgery, and the other with Enu/PO. No new recurrence was found thereafter. All patients were satisfied with their facial appearance.

CONCLUSIONS

The Enu/PO technique is excellent in preserving appearance and functions and with a low risk of recurrence, is a reliable option for the management of large mandibular cystic ameloblastomas.

A review of literature on ameloblastoma in children and adolescents and a rare case report of ameloblastoma in a 3-year-old child

A rare case report of a plexiform unicystic ameloblastoma in a 3-year-old girl stimulated us to conduct a review of literature to understand the correlation of this tumor with various factors such as that of age, sex, histopathological correlation, and its incidence rates pertaining to children and adolescent population. This is a case report of ameloblastoma in a 3-year-old patient, along with a literature review of ameloblastoma in relation to age. A computerized literature search using Medline was conducted for published articles on treatment of ameloblastoma. MeSH phrases used in search were ameloblastoma AND age; ameloblastoma AND children. The search was restricted to published articles from 1970 to 2010, as the histological features were not clearly defined until 1st edition of WHO histological classification of odontogenic tumors of 1971, search parameter was also set to select literatures under English language only. An additional systematic hand search was also conducted simultaneously to identify other published articles, considering similar parameters as used for Medline search. Most of search result yielded literatures in which primary importance were given to treatment patterns and prognosis of intervention, there were not much specific article or meta analysis which reviewed on the affected age range of ameloblastoma exclusively. We reviewed the identified literatures with patients' age, case numbers, incidence, sex, location, and histopathology. The statistical data collected were exported to SPSS 16.0 for windows software which performed a descriptive analysis giving an average mean age of 14.1 years (range from 4 to 20); with maximum mean age being 16.0 and minimum mean age being 10.8 with standard deviation of 1.60. Majority of lesions 91.86% (327 of 356) were found between the age group of 11 and 20 years, only 8.14% (29 of 356) were below the age of 10 years. This rare case report highlights occurrence of plexiform unicystic ameloblastoma in maxilla of a 3-year-old girl, which is very much incongruent with the various review of literature on ameloblastoma in children and adolescents. We have emphasized the significance of patient's age and histopathological pattern of the tumor as it has its influence on the treatment plan. However, there is much of research needed with focus in respect to age, histological pattern, and treatment outcomes.

Trends in Pediatric Ameloblastoma and its Management: A 15 year Indian Experience

PURPOSE

The purpose of this study is to put forth our 15 year experience with pediatric ameloblastoma in the Indian population.

MATERIALS AND METHOD

This retrospective study was carried out in the pediatric group of 18 years and below, presenting with and diagnosed for ameloblastoma, at our institution over the past 15 years. The required data was collected by reviewing patient's case notes, relevant radiographs, histopathological reports, and treatment charts. The incidence of pediatric ameloblastomas with respect to age, sex, site of occurrence, histopathologic type, the type of treatment instituted, and recurrence rate was noted.

RESULTS

Of the total 165 pediatric tumors, ameloblastoma was the most common, 29 cases (17.5%). It occurred commonly in the age group of 12-18 years (mean age 14 years) with a marked male predilection. The most common site of occurrence was the posterior mandible. Majority were of the unicystic type. Two ameloblastomas which appeared as unilocular radiolucency were diagnosed as solid type. Twenty-eight were benign and one was a rare malignancy (Ameloblastic carcinosarcoma). Only two recurrences were noted over 15 years, of which one tumor interestingly recurred as a peripheral variety which responded well to local excision. Ameloblastomas were either enucleated with mechanical curettage or resected followed by primary reconstruction with either a reconstruction plate or free fibula flap.

CONCLUSION

We conclude that ameloblastomas are not uncommon in Indian pediatric population. Unilocular, unicystic ameloblastomas in the pediatric age group can be treated conservatively owing to their growth potential. Emphasis must be given to a long-term regular follow-up, conserving a more radical approach in case of a recurrence. However, Unilocular appearing ameloblastomas may be of the solid type which needs to be borne in mind as it not only alters the treatment modality but also emphasizes the importance of pre-operative incisional biopsy. Solid and unicystic aggressive ameloblastomas must be treated radically. Primary reconstruction with the free fibula flap is a viable option.

Unicystic ameloblastoma in an infant: a management dilemma

The authors describe the conservative management of a rare case of unicystic ameloblastoma (mural subtype) in a 10-month-old girl, the youngest patient reported thus far in the literature. Rather than subject the infant to further surgery, it was decided to monitor her closely and perform an additional operation in the event of recurrence, thus enabling uninterrupted mandibular growth and tooth development. The patient is now 3.5 years old and periodic follow-up is ongoing, with no evidence of recurrence.

Does a difference exist in inferior alveolar canal displacement caused by commonly encountered pathologic entities? An observational study

PURPOSE

The aim of the present study was to investigate whether a difference exists in the location of the displaced inferior alveolar canal (IAC) and neurovascular bundle (toward the buccal or lingual cortex) among odontogenic tumors and vascular lesions. If some consistency exists in the manner in which the canal and bundle are displaced on radiographic examination, the nature of the mandibular lesion under examination could be anticipated. This information would assist the surgical team in treatment planning, diagnostic biopsy, and resection, especially in cases of intraosseous vascular pathologic findings.

MATERIALS AND METHODS

A retrospective review of the computed tomography images obtained for odontogenic tumors and vascular anomalies treated at the Department of Oral and Maxillofacial Surgery, University of Illinois at Chicago, from January 2000 to June 2010 was undertaken. The IAC and neurovascular bundle were traced from the lingula to the mental foramina, and its location within the mandible was recorded at 3 specific points.

RESULTS

In the odontogenic tumor group, we found that the canal with the neurovascular bundle was displaced either toward the buccal cortex of the mandible or the inferior border, but it was never identified lingually. In contrast, all the vascular anomalies had displaced the structures toward the lingual aspect of the mandible at all selected points.

CONCLUSIONS

To our knowledge, this is the first study to have examined the potential differences in the displacement of the inferior alveolar neurovascular bundle caused by the 2 commonly encountered pathologic entities in the maxillofacial skeleton: odontogenic tumors and vascular anomalies. We identified a striking difference in the manner of the IAC and its contents that was consistent among the tumors in the 2 groups. The location of the IAC in relationship to the pathologic entity under investigation could prove valuable in the differential diagnosis and assist with planning the biopsy. Additional investigation with a larger number of cases of these 2 groups of lesions involving the mandible is warranted to confirm our preliminary findings.