Management of ameloblastoma: a changing perspective

Silent Jaw Expansion: A Rare Case of Posterior Maxillary Ameloblastoma

Ameloblastoma is a rare odontogenic tumour that develops from the epithelial remains of the dental lamina. It is a benign but locally aggressive neoplasm that typically manifests as slow-growing tumours in the jaw, with posterior maxilla ameloblastoma being the rarer occurrence compared to mandibular ameloblastoma. This case report is about a 46-year-old Malay man who presented with a two-month history of left palatal and cheek swelling, along with symptoms such as left eye blurring, nasal block, and dysphagia. Imaging revealed a massive cystic lesion in the left maxillary sinus, which was diagnosed as a multicystic ameloblastoma after biopsy. The patient underwent surgical resection with a partial maxillectomy and was treated postoperatively with antibiotics, steroids, and regular follow-up appointments. The histopathological examination confirmed the diagnosis, and the patient was given a dental obturator to cover the defect intraorally. He is currently under annual surveillance with no signs or symptoms of recurrence.

Wide Excision with Immediate Reconstruction of the Mandible Using Free Fibular Flap in Ameloblastoma of the Mandible-A Need of Time: Our Experience of 37 Cases

Background  Ameloblastoma is a benign yet locally aggressive odontogenic tumor of the jaw with high recurrence rates. Despite many studies, the search is still on for the treatment approach which can render the acceptable recurrence rates with good functional and esthetic results.

Methods  In this prospective study, we operated on 37 patients of mandibular ameloblastoma between 2009 and 2018. Two patients were treated with curettage and chemical sterilization of the cavity. Resection of a tumor with a 2-cm margin was performed in the rest of 35 patients. The mandibular defect was primarily reconstructed with the microvascular free fibular flap in 29 patients.

Results  The follow-up ranged from 6 months to 7.7 years with a mean of 5.1 years. A tumor recurred within a year in all two patients (100%) treated with curettage. Out of 35 radical excisions, only one patient (2.85%) developed recurrence 3 years after the disease-free interval. Good mouth opening, intelligible speech, satisfactory lower jaw shape, and facial profiles were achieved in all 29 patients who were treated with primary free fibular flap.

Conclusion  We prefer wide excision with 2-cm margins on each side of a tumor with the primary reconstruction of the mandible in all cases of mandibular ameloblastoma. The free fibular microvascular flap is our treatment of choice as all defects of the mandible can be reconstructed with the free fibular flap. Wide excision is the key to prevent a recurrence.

Ameloblastomas of the mandible and maxilla

Ameloblastoma is a histologically benign but locally aggressive tumor of the jaws. We conducted a retrospective cohort study to review the clinical, radiologic, and pathologic features of patients with ameloblastoma of the mandible and maxilla and to report the outcomes of treatment. Our study population was made up of a series of 30 consecutively presenting patients-15 men and 15 women, aged 19 to 81 years (median: 61.5)-who had undergone their primary treatment of ameloblastoma of the mandible or maxilla at Memorial Sloan Kettering Cancer Center from January 1987 through December 2012. In addition to demographic data, we compiled information on clinical characteristics, imaging findings, the type of surgery, surgical margins, adjuvant treatments, histologic patterns, length of follow-up, time to recurrence, treatment of recurrence, and factors that had an influence on recurrence. All but 2 patients with negative margins were cured. Favorable outcomes were associated with the administration of adjuvant postoperative radiotherapy for patients with positive margins and a repeat resection for patients with recurrences. Complete excision with negative margins, however, remains the gold standard for curative treatment.

"Evaluation of safety margin" in ameloblastoma of the mandible by surgical, radiological, and histopathological methods: An evidence-based study

OBJECTIVE

The purpose of this study is to elicit the amount of safety margin necessary around the ameloblastic lesion in view of preventing further recurrence.

MATERIALS AND METHODS

The study consisted of 25 cases of mandibular ameloblastoma. Diagnosis was based on clinical and radiological analysis and confirmed by histopathological report. An incisional biopsy was done preoperatively to confirm the diagnosis. Segmental resection was planned for all the cases. After the resection, postoperative panoramic radiograph of the specimen was taken followed by histopathological examination of its margin to detect tumor cell infiltration.

RESULTS AND CONCLUSION

In all our cases, the ameloblastoma was infiltrating in nature. A follow-up period of 10 years showed neither recurrence nor implant failure. In our study, we conclude our safe margin for infiltrating variant of ameloblastoma based on histopathological report of the resected specimen.

Recurrent Ameloblastoma in the Free Fibula Flap: Review of Literature and an Unusual Case Report

Ameloblastoma is the second most common odontogenic tumor of the oral cavity with the primary site being the mandible. The ratio of maxillomandibular involvement however is 5:1 in favor of the mandible. The most common complaint is a painless swelling over the mandibular area. Despite its benign nature, ameloblastoma has a high local recurrence rate, with the most recurrences seen within 5 years after operation. Biopsy and radiological evaluation may be helpful in differentiating the subtypes of ameloblastoma. Differentiation is important because some subtypes are more aggressive than the others. Preoperative planning may be done according to this classification, which can help decrease the recurrence rate. In our case, a 26-year-old female patient with recurrent ameloblastoma which developed on the fibular flap is presented. The free fibular flap and the left parasymphyseal part of the mandible were totally excised. Ameloblastoma was confirmed on pathological examination. We reconstructed the left mandibular site with a reconstruction plate and recurrence was not seen during follow up period.

Ameloblastomas: clinical-histopathological evaluation of 85 cases with emphasis on squamous metaplasia and keratinization aspects

OBJECTIVES

Ameloblastoma is a benign odontogenic neoplasm with an origin reputed to reactivation of odontogenic structures. Histological classification is based on microscopic features and architectural distribution of neoplastic cells. The importance of squamous metaplasia and keratinization has been disputed in ameloblastomas. Clinical and histopathological aspects were evaluated of 85 ameloblastomas, with attention to keratinization and squamous metaplasia features.

STUDY DESIGN

Clinical-demographical information of 85 ameloblastomas were gleaned from the medical records. Microscopic analysis of all cases was carried out with emphasis on keratinization aspects of each tumor.

RESULTS

Most ameloblastomas (54.12%) were diagnosed in males with a mean age of 37 years. Fifty-six patients were Caucasians (65.88%) and the mandible was affected in 68 (89.4%) cases. Most cases analyzed presented areas of squamous metaplasia/keratinization. Recurrence was detected in 16 cases; this was not related to keratinization aspects of the tumor.

CONCLUSIONS

Keratinization is a common feature in ameloblastomas with no impact in tumor behavior.

Mandibular resection via mandibular-lip L flap for the treatment of extensive multicystic Ameloblastoma

Ameloblastoma is a benign odontogenic tumor accounting for 1% of all tumors of the maxilla and mandibula. The mandibula is committed in 85% of the cases. The tumor is locally invasive, able to infiltrate bone marrow spaces, without radiographic or macroscopic evidence. High recurrence rates are associated with different surgical techniques, which range from simple tumoral enucleation to extensive resections. The authors report a case of a 26-year old female patient with an 8-year history of progressive, non-tender, swelling of the left mandibular region. The intraoral examination showed that the floor of mouth was raised on the left side by a bulging along the bottom of the left mandibular vestibule as well as the lingual region. Over this area, there were ulcerated areas in the alveolar region of the molars and mucosal fenestration in the alveolar and lingual regions were present. A panoramic radiography revealed a multicystic lesion, resembling the soap-bubble shape endosseous lesion. The computed tomography revealed an expandable multicystic lesion compromising both mandibular cortices. The patient underwent a biopsy, which revealed the diagnosis of a multicystic variant of Ameloblastoma, with plexiform pattern, treated with left mandibular resection and immediate installation of a customized prosthesis. After a year of follow-up, no evidence of the tumor relapse was evidenced.

Wide surgical excision with split rib graft reconstruction of mandible for ameloblastoma; our 10 year experience

Ameloblastoma or adamantinoma is a benign odontogenic tumour arising in facial bones mostly in mandible. There are different modalities of treatment for ameloblastoma viz. chemotherapy, radiation therapy, curettage and liquid nitrogen but surgical resection or enucleation remains the most definitive treatment for this condition. After surgical excision mandibular defect can be reconstructed by non vascularised bone graft or free tissue transfer. we are presenting a detailed study of 50 patients in which mandible was reconstructed with non vascularised split rib graft after surgical resection of ameloblastoma. This is easy, less time consuming and requires no expertise with excellent results.

Achieving adequate margins in ameloblastoma resection: the role for intra-operative specimen imaging. Clinical report and systematic review

Background

Ameloblastoma is a locally aggressive odontogenic neoplasm. With local recurrence rates reaching 90%, only completeness of excision can facilitate cure. Surgical clearance has widely been based on pre-operative imaging to guide operative excision margins, however use of intra-operative specimen x-ray or frozen-section has been sought to improve clearance rates, and advanced imaging technologies in this role have been proposed. This manuscript aims to quantify the evidence for evaluating intra-operative resection margins and present the current standard in this role.

Method

The current study comprises the first reported comparison of imaging modalities for assessing ameloblastoma margins. A case is presented in which margins are assessed with each of clinical assessment based on preoperative imaging, intra-operative specimen x-ray, intra-operative specimen computed tomography (CT) and definitive histology. Each modality is compared quantitatively. These results are compared to the literature through means of systematic review of current evidence.

Results

A comparative study highlights the role for CT imaging over plain radiography. With no other comparative studies and a paucity of high level evidence establishing a role for intra-operative margin assessment in ameloblastoma in the literature, only level 4 evidence supporting the use of frozen section and specimen x-ray, and only one level 4 study assesses intra-operative CT.

Conclusion

The current study suggests that intra-operative specimen CT offers an improvement over existing techniques in this role. While establishing a gold-standard will require higher level comparative studies, the use of intra-operative CT can facilitate accurate single-stage resection.

Surgical management of ameloblastoma: Conservative or radical approach

AIM

The ameloblastoma is a benign odontogenic tumor of epithelial origin that exhibits a locally aggressive behavior with a high level of recurrence, being believed theoretically to come from dental lamina remains, the enamel organ in development, epithelial cover of odontogenic cysts or from the cells of the basal layer of the oral mucosa. Especially larger, aggressive lesions require a more radical surgical approach resulting in large jaw defects. This paper discusses our experiences in the management of ameloblastoma tumor in 20 such patients.

MATERIALS AND METHODS

A review of 20 cases of ameloblastoma (6 in the maxillary and 14 in the mandibular region) is presented. The lesions were between 4 and 8 cm in diameter. The methods of treatment consisted of radical surgery (i.e., segmental resection) and conservative treatments (i.e., enucleation with bone curettage). Half the cases were treated conservatively and others surgically.

RESULTS

Enucleation with curettage was done in 10 cases, out of which six (60%) showed recurrence, whereas one (10%) case in the surgical group showed recurrence. Relatively higher tendencies of recurrence were observed in the cases treated conservatively. The aesthetic and functional outcomes were satisfying in all patients.

CONCLUSION

According to our opinion, radical surgical resection of ameloblastoma is the treatment of choice, followed by the reconstruction of the defects, allowing good functional and aesthetic outcome.

Plexiform ameloblastoma

The ameloblastoma is a benign but aggressive neoplasm of odontogenic origin. However, no enamel or hard tissue is formed by the tumor cells. Ameloblastomas are infamous for their invasive growth and their tendency to recur. Robinson (1937) as a benign tumor that is ‘usually unicentric, nonfunctional, intermittent in growth, anatomically benign and clinically persistent.’ They may occur at any age, even though nearly half of the tumors do occur between the ages of 20 and 40 years. This is the most common neoplasm affecting the jaws, yet only accounts for 1% of all tumors of the maxilla and mandible and 11% of all odontogenic tumors.

This report presents a case of ameloblastoma involving entire ramus and part of body of mandible with resorption of the mesial and distal root apices of second molar and distal root of mandibular first molar. The lesion extending till the base of mandible surrounding the crown of the unerupted third molar resembling the dentigerous cyst. This was surgically resected followed by harvesting the contralateral sixth costochondral rib graft.

How to cite this article: Celur S, Babu KS. Plexiform Ameloblastoma. Int J Clin Pediatr Dent 2012;5(1):78-83.

Evaluation of the inferior alveolar canal for cysts and tumors of the mandible-comparison of multidetector computed tomography and 3-dimensional volume interpolated breath-hold examination magnetic resonance sequence with curved multiplanar reformatted reconstructions

OBJECTIVE

To evaluate the mandibular canal using volume interpolated breath-hold examination (VIBE) sequencing in patients with cysts and tumors of the mandible.

MATERIALS AND METHODS

Twenty-five patients with mandibular cysts and tumors were recruited for a study in the authors' institution to compare the role of multidetector row computed tomography with magnetic resonance imaging (MRI) in jaw lesions. Of these 25 patients, VIBE was performed in 12 patients (age range, 16 to 52 yrs; 11 male and 1 female patients) and formed the study group. The status (normal/destroyed/attenuated) and position of the inferior alveolar canal (normal/displaced) on panoramic reconstructed computed tomographic (CT) images and curved multiplanar reformatted (MPR) images reconstructed from VIBE images were analyzed. The contralateral normal mandibular canal was used as the control in these patients.

RESULTS

In all 12 patients, the inferior alveolar canal on the normal side was visualized as a hyperintense structure in relation to the hypointense bone on the curved MPR VIBE images. In 9 patients, the inferior alveolar canal was equally well visualized on panoramic CT and curved MPR VIBE images. In 2 patients, the inferior alveolar canal was better visualized on curved MPR VIBE images; in 1 patient, the course of the mandibular canal was better seen on panoramic CT images.

CONCLUSIONS

MR reconstructions with VIBE sequencing as source images provide images comparable to CT reconstructed images for evaluation of the mandibular canal. Three-dimensional (3D) VIBE sequencing can be added to the MR protocol to visualize the inferior alveolar neurovascular bundle. 3D VIBE sequencing increases the diagnostic capabilities of MRI when used to image mandibular cysts and tumors.

Ameloblastoma relapse after 16 years of resection in symphysis of mandible sparing the bone graft

Ameloblastoma is a tumor derived from epithelium involved in odontogenesis. Although it is considered a benign tumor, its clinical behavior may be regarded as lying between benign and malignant. It is characterized by slow but persistent growth, local infiltration into adjacent tissues and recurrences; however, metastases are rare. Diagnosis mainly from tissue biopsy and characteristic finding on plain X-rays does assist in differentiating between types of ameloblastoma. The challenges in the management of this tumor are to provide complete excision as recurrence may occur in incomplete removal and also to reconstruct the bony defect in order to give reasonable cosmetic and functional outcome to the patient.

Recurrent ameloblastoma of the infratemporal fossa: diagnostic implications and a review of the literature

It is unusual for odontogenic tumours such as ameloblastoma to occur in the infratemporal fossa. Although these odontogenic tumours usually arise in jaws, they can infiltrate into the infratemporal region, pterygomaxillary space or fissure, invading soft tissues by way of extension. A case of recurrent ameloblastoma in the infratemporal fossa region arising from an extension of the lesion from the site of previous occurrence in the right mandibular body is reported.

Long-term follow up on recurrence of 305 ameloblastoma cases

The aim of this study was to determine the appropriate treatment for ameloblastoma by considering the factors associated with recurrence, and to make a quantitative prediction of the risk factors for recurrence. Data on age and gender distribution, location of the tumour, histopathological findings, treatment method, and whether or not patients had a preoperative biopsy confirmation report were collected in 305 cases (239 patients; M: 139, F: 100) of ameloblastoma diagnosed and treated in 1985-2002. After initial statistical evaluation (chi(2)-test and Fisher's exact test), logistic regression analysis was performed to check relative significance and predict recurrence. The disease-free survival function curves of the patients with or without recurrence were obtained by the Kaplan-Meier method and compared using univariate regression analysis. The correlation between recurrence and the treatment method or histopathological type was significant. The differences between the 'conservative' and 'resection with bone margin' and between the 'conservative' and 'segmental resection or maxillectomy' groups in terms of disease-free survival were highly significant. The difference between the 'resection with bone margin' and 'segmental resection or maxillectomy' groups was not significant. A resection with safety margin is the best method to treat most proven ameloblastomas, and conservative treatment is reasonable for patients in their first decade or with unicystic or plexiform ameloblastoma.

Extensive ameloblastoma of the jaws: surgical management and immediate reconstruction using microvascular flaps

OBJECTIVE

Ameloblastoma is a rare histological benign but locally aggressive tumor with a marked tendency for recurrence. Especially larger, aggressive lesions require a more radical surgical approach resulting in large jaw defects. The purpose of this study is to analyze the long-term functional and esthetic results after immediate reconstruction of large jaw defects using microvascular flaps.

STUDY DESIGN

A review of 7 cases of giant ameloblastoma (2 in the maxillary and 5 in the mandibular region) is presented. The lesions were between 4 and 8 cm in diameter. All patients were treated by a radical surgical protocol. All cases were immediately reconstructed using microvascular grafts from either the scapula or the iliac crest bone. Dental implants were inserted in all patients after removal of the osteosynthesis material.

RESULTS

All patients were prosthetically rehabilitated. All implants survived throughout the observation time. The esthetic and functional outcomes were satisfying in all patients. No case of recurrence of the tumor could be observed so far.

CONCLUSION

According to our opinion, immediate reconstruction is the treatment of choice after radical surgical excision of ameloblastoma. This 1-step procedure decreases the number of surgeries and allows earlier prosthetic rehabilitation.

Surgical Management of Ameloblastoma in the Mandible: Segmental Mandibulectomy and Immediate Reconstruction With Free Fibula or Deep Circumflex Iliac Artery Flap (Evaluation of the Long-Term Esthetic and Functional Results)

PURPOSE

Ameloblastoma is responsible for 1% of all the oral and maxillomandibular cysts and tumors. It is odontogenic in origin and benign in nature but it has a high percentage of local recurrence rate and possible malignant development when treated inadequately. With the advancement of craniofacial surgical techniques, use of free flaps for mandibular reconstruction, and dental rehabilitation (such as osseointegration), the segmental mandibulectomy and immediate reconstruction with free flaps are beginning to be used more effectively for the treatment of the mandibular ameloblastoma. The aim of this article is to evaluate the clinical results of the patients with mandibular ameloblastoma who were treated with segmental mandibulectomy and immediate reconstruction with free flaps.

PATIENTS AND METHODS

We present 11 patients who had segmental mandibulectomy and immediate reconstruction with free deep circumflex iliac artery or fibular flap for treatment of mandibular ameloblastoma. The average age of the patients was 25.4 years (range, 18-38 years). The patients were followed up for a mean of 29.3 months (range, 17-38 months). The functional and esthetic results were also evaluated by using a questionnaire in the long term. The questionnaire consisted of questions addressing oral continence, diet, social activities, speech, and facial appearance.

RESULTS

All flaps survived totally. Recurrence was not detected during the follow-up period. It was found that all patients had good esthetic and functional results after immediate reconstruction. The social activities of patients also were not affected after treatment.

CONCLUSIONS

We experienced that segmental mandibulectomy with safe borders and immediate reconstruction with free fibula flap or deep circumflex iliac artery (DCIA) flap is an ideal treatment method for mandibular ameloblastoma. The functional and esthetic results are also detected as very satisfactory for the patients.

Growth characteristics of large mandibular ameloblastomas: report of 5 cases with implications for the approach to surgery

The aim of this study was to establish surgical guidelines based on the growth pattern of ameloblastomas in relation to the possible infiltration of the cortical bone, the inferior alveolar nerve, the periosteal layer and the surrounding soft tissues. Five male patients with voluminous mandibular ameloblastomas were treated by means of radical surgery. Ameloblastomas showed an invasive growth pattern in the cancellous bone with small tumour nests at a maximum distance of 5mm away from the bulk of the tumour. Expansive and invasive growth in the Haversian canals was observed. There was no invasion of the inferior alveolar nerve. The mucoperiosteal layer was invaded but not perforated. No invasion was observed in the surrounding soft tissues of the periosteum and in the skin tissue. A local resection with a surgical margin of spongious bone of 1cm is suggested. When the tumour is radiologically closer than 1cm to the inferior border of the mandible, a continuity resection is mandatory. A conservative approach concerning the inferior alveolar nerve is suggested. Removal of an excess of perimandibular soft tissue is not indicated. The overlying attached mucosal surface should however be excised together with the underlying bone.

A case of recurrent ameloblastoma developing in an autogenous iliac bone graft 20 years after the initial treatment

A case of recurrent ameloblastoma developing in an autogenous iliac bone graft 20 years after radical resection of primary mandibular ameloblastoma is presented. This case showed extensive bony resorption extending throughout the auto-grafted bone. Seeding to the graft bone was suspected as a cause of the recurrence in the iliac bone graft because wide destruction of the graft bone was observed without any prior signs and symptoms of intraoral mucosa. Consequently, extensive resection of bone as well as adjacent soft tissue was performed. Persistent follow-up examination is essential for management of ameloblastoma.

Periapical ameloblastoma--a case report

Ameloblastomas, although often benign, are locally aggressive odontogenic lesions. Presentation of this lesion as a pericoronal radiolucency associated with an impacted tooth is well documented. Presentation of this lesion as a solitary periapical radiolucency associated with a non-impacted tooth however, is rare. Periapical presentation of this lesion may confuse practitioners.

Mandibular ameloblastoma: analysis of surgical treatment carried out in 60 patients between 1977 and 1998

Ameloblastoma, a benign tumor of odontogenic type, represents 10% of all tumors of the jawbone. It is localized in the mandible in 80% of cases and in the upper jaw in the remaining 20%. In every case, the selection of the surgical treatment to be applied must consider some fundamental elements, including the age and general state of health of the patient, the clinicopathological variant, and the localization and extent of the tumor. In addition, it is necessary to evaluate whether the neoplasm to be treated is a primitive lesion or a recurrence. Although ameloblastoma has relative histological characteristics of benignity, this neoplasm has a high percentage of local recurrence and possible malignant development when treated inadequately. The aim of this study was to carry out a follow-up of 60 patients treated for ameloblastoma of the mandible between 1977 and 1998, analyzing the problems faced in removing this benign neoplasm and those concerning reconstruction of the surgical defect.

Growth characteristics of ameloblastoma involving the inferior alveolar nerve: a clinical and histopathologic study

OBJECTIVE

Growth characteristics of ameloblastomas involving the inferior alveolar nerve were examined to determine the most appropriate surgical management of the nerve at the time of the surgical procedure.

STUDY DESIGN

Clinical and histopathologic examinations were performed on 22 resected mandibles in which the inferior alveolar nerve was lying adjacent to, or contained within, the tumor.

RESULTS

Patterns of tumor involvement of the nerve bundle were evaluated with respect to the presence of bone (11 patients) or connective tissue wall (7 patients) between the tumor and the nerve bundle, and tumor infiltration of perineural connective tissue (4 patients). Neither invasion into the nerve sheath nor invasion into the nerve itself by the ameloblastoma was detected. Tumor infiltration of the tissue surrounding the nerve was identified for the multicystic and solid types but not for the unicystic type. Presence of bone or connective tissue wall between the tumor and the nerve bundle was dominant in the unicystic and plexiform ameloblastomas, whereas tumor infiltration of the perineural tissue was frequently observed in ameloblastomas with the follicular pattern.

CONCLUSION

The preservation of the inferior alveolar nerve may be possible in the management of the unicystic type of ameloblastoma. However, a more radical approach is necessary for treatment of multicystic or solid tumors, especially those exhibiting a follicular pattern.

Unicystic ameloblastoma: a clinicopathologic study of 33 Chinese patients

The term unicystic ameloblastoma refers to those cystic lesions that show clinical, radiographic, or gross features of a jaw cyst, but on histologic examination show a typical ameloblastomatous epithelium lining part of the cyst cavity, with or without luminal and/or mural tumor growth. To ascertain the clinicomorphologic spectrum and biologic behavior of this tumor group, the clinicopathologic features of 33 unicystic ameloblastomas from Chinese patients were studied. This series represents approximately 19% of all cases of ameloblastoma accessioned in the authors' hospital during a 15-year period. Twenty-one patients were male and 12 were female, for a total of 33 patients. The age at diagnosis ranged from 8 to 60 years (mean, 25.3 yrs) and peaked at the second and third decades (70%), Thirty tumors (91%) occurred in the mandible and three in the maxilla. Of the 29 patients with a radiographic record, an expansive unilocular radiolucency was seen in 22 cases, and was multilocular in seven cases. Microscopically, all tumors demonstrated a generally monocystic growth pattern. Eight tumors were simple cystic, 10 comprised intraluminal tumor nodules, and the remaining 15 had a conspicuous component of infiltrative tumor islands in the cyst capsule. The cystic tumor linings invariably showed, at least in part, a typical ameloblastomatous pattern that was often accompanied by epithelial areas of various histologic appearance. Follow up of 29 patients revealed no recurrence in less than 4 years of follow up, but did reveal a 35% recurrence rate at more than 4 years of follow up. The average interval to recurrence was approximately 7 years. Recurrence also appeared to relate to histologic subtypes of unicystic ameloblastoma, with those invading the fibrous wall having a rate of 35.7%, but other types having a rate of 6.7%. Despite the fact that unicystic ameloblastoma may, in general, compare favorably with its solid or multicystic counterpart in terms of clinical behavior and response to treatment, the subsets of the maxillary lesions or tumors containing invading islands in the fibrous wall could have a high risk of recurrence. Furthermore, recurrence of unicystic ameloblastoma may be long delayed, and a long-term postoperative follow up is essential to the proper management of these patients.

Effect of preservation of the inferior and posterior borders on recurrence of ameloblastomas of the mandible

OBJECTIVE

The purpose of this study was to evaluate the experience and results of using a rational radical conservative approach in the surgical treatment of mandibular ameloblastomas.

STUDY DESIGN

A retrospective analysis of every patient with an ameloblastoma of the mandible treated in the Department of Oral Medicine and Oral Surgery at the Jordan University of Science and Technology between 1989 and 1999 was conducted. All were operated on by the author, who used a uniform surgical protocol in every case. All soft tissues in contact or overlying the lesion and a wide margin of cancellous bone related to the tumor were destroyed. The compact bone comprising the lower border of the mandible and the posterior border of the ascending ramus together with the nutrient periosteum attached to them were preserved, thus maintaining the continuity of the mandible and the facial contours. When teeth, soft tissues, or both were involved, they were destroyed. All patients were reviewed annually for a follow-up period of 3 to 10 years (mean, 6.5 years) by the same clinician.

RESULTS

All ameloblastomas were located in the mandible; 21 were in the angle/molar region and the ascending ramus, and 2 cases were in the anterior region. There was no clinical or radiographic evidence of recurrence observed during the follow-up period.

CONCLUSION

Ameloblastoma has a high rate of local recurrence if it is not adequately removed. The findings of this study to date suggest that the technique of rational radical conservative resection may have a place in the treatment of ameloblastoma of the mandible and is worthy of further trial.

Zygomatic-transmandibular approach for giant tumors of the infratemporal fossa and parapharyngeal space

OBJECTIVE

The surgical anatomy of the infratemporal fossa and parapharyngeal space is often not properly understood by neurosurgeons, because these areas are more related to other medical disciplines. This article provides a detailed description of the infratemporal fossa and parapharyngeal space anatomy in cadaveric specimens and offers a neurosurgical perspective on a surgical approach that allows wide exposure and complete resection of giant tumors in this location.

METHODS

Ten cadaveric specimens were prepared for anatomic study. Dissections were performed to emphasize the relationship between bone, muscles, and neurovascular structures and to simultaneously expose the middle cranial fossa, the infratemporal fossa, and the parapharyngeal space. Ten patients with giant lesions in these areas (with maximum tumor diameter >8 cm) were treated via this approach.

RESULTS

The main obstacles to approaching the infratemporal fossa and the parapharyngeal space are the zygomatic arch, the parotid gland, the facial nerve, and the ascending ramus of the mandible. Thus, by combining a pterional-zygomatic craniotomy with transmandibular access, working up and down the parotid gland, the exposure is wider and safer. Among the 10 patients treated, tumors were totally resected in 7, subtotally resected in 2, and partially resected in 1. Morbidity was unremarkable, and, in 8 patients, clinical status improved dramatically.

CONCLUSION

The zygomatic-transmandibular approach allows resection of giant lesions in the middle cranial base, when they are invading the infratemporal fossa and parapharyngeal space, with a low morbidity rate.

Giant Ameloblastoma: Report of an Extreme Case and a Description of its Treatment

Ameloblastoma is an odontogenic tumor that usually occurs in the mandible. It is an aggressive but benign tumor of epithelial origin that is rarely metastatic. We report the case of a 53-year-old woman who had a massive ameloblastoma of the mandible. The tumor measured 15.2 × 11.4 × 12.0 cm. The patient had oral bleeding that required a transfusion. The workup included three-dimensional imaging, arteriography, and embolization to control bleeding. Surgical management entailed the resection of the entire left mandible and right symphysis, followed by reconstruction with a free fibular flap. To our knowledge, this is the largest reported ameloblastoma managed with three-dimensional imaging, radical resection, and free-flap reconstruction. This article also reviews aspects of the differential diagnosis, pathology, and management of jaw tumors.

Clinical features and management of oral and maxillofacial tumors in children

OBJECTIVE

To clarify the characteristics of oral and maxillofacial tumors in children, we carried out a clinical study of such tumors and reviewed the relevant procedures for treatment. Study design. Medical records of 105 patients less than 15 years of age who were treated for oral and maxillofacial tumors during the 20 years between 1976 and 1997 were retrieved and analyzed.

RESULTS

Of the 105 cases, 102 (97.1%) involved tumors that were benign; only 3 patients (2.9%) had tumors that were malignant. With regard to benign soft tissue tumor, the most common type was hemangioma (25/69; 36.2%), the second most common type was papilloma (19/69; 27.5%), and the most common site was the tongue. With regard to bone tumor, the most common type was odontoma (14/33; 42.4%), the second most common type was ameloblastoma (11/33; 33.3%), and the most common site was the mandible. Most of the odontogenic tumors (25/28; 89.3%) developed in patients more than 6 years of age; these tumors may develop after dental crown formation. In each case of benign soft tissue tumor, resection was performed; 4 of these tumors (2 hemangiomas, 1 lymphangioma, and 1 papilloma) recurred, but after re-resection recurrence has not been found for more than 4 years. In the cases of benign jawbone tumor, resection and enucleation were the procedures principally performed; 3 ameloblastomas recurred after enucleation, but after relatively wide resection for these recurrent tumors there has been no recurrence for more than 17 years. With regard to the ameloblastomas, enucleation with preservation of the periosteum was effective and bone regeneration occurred rapidly.

CONCLUSIONS

Most oral and maxillofacial tumors in children are benign. In any case of such benign tumor, including ameloblastoma, minimal surgical treatment should be the procedure of first choice.

Histopathologic features and management of ameloblastoma: study of 20 cases

BACKGROUND

Odontogenic ameloblastoma (OA) of the jaws is a rare neoplasia of the oral cavity (0.78%) with a 5:1 mandible/maxilla relation, with the molar region and the ascendant ramus being the most affected areas. Comparing our results with the literature demonstrated to us that this tumor may be considered to be a worldwide problem due to the similarity in clinical findings among different ethnic groups

CASE SERIES

The purpose of this study of 20 patients with ameloblastoma of the mandible and maxilla diagnosed at the Stomatology and Head and Neck Services of Heliópolis Hospital, São Paulo, Brazil, from 1980 to 1997, was to establish the histopathologic pattern of classification of those tumors through optical microscopy and the relation of this histopathology to therapeutic management. Using the Regeze, Kerr and Courtney classification (1978), we diagnosed follicular tumor in 11 cases, plexiform in 6 cases and unicystic in 3 cases, and performed surgical resection with a safety margin of 1.5 to 3.0 cm in the follicular and plexiform cases and bone curettage in the unicystic cases.

Desmoplastic variant of ameloblastoma in Chinese patients

Desmoplastic ameloblastoma is a rare tumour, and we know of only 43 previously reported cases. We report seven Chinese patients (five men and two women) with the desmoplastic variant of ameloblastoma, which makes up 9% of all ameloblastomas diagnosed during the years 1981-1995. The age ranged from 18 to 68 years (mean 43). Five of the tumours were in the maxilla and two were in the mandible. Five of them were situated anteriorly, the remaining two cases involving both anterior and posterior maxilla. The features of the 42 cases previously reported were reviewed and were compared with those in the present study. Our results differ in that we found a male predominance, wider age range and more tumours in the maxilla. Histologically, this variant of ameloblastoma is characterized by abundant collagenous stroma. Because the epithelial clusters may show prominent squamous metaplasia or may be compressed into thin strands in most areas, the appearance may mimic a squamous odontogenic tumour or odontogenic fibroma. The behaviour of this variant of ameloblastoma is likely to be the same as that of the classic ameloblastoma.

Case report. Aggressive ameloblastoma treated with radiotherapy, surgical ablation and reconstruction

Surgical resection of aggressive solid or multicystic ameloblastoma is a well-documented and accepted treatment modality. Controversies exist, however, with regard to the extent of operative intervention. Unresectable lesions have been treated with radiation or combined radiation and chemotherapy. The authors present a case report of a patient with recurrent ameloblastoma who underwent simultaneous hard- and soft-tissue reconstruction.

Management of solid ameloblastoma of the jaws with liquid nitrogen spray cryosurgery

OBJECTIVE

This study evaluated the results of the use of curettage followed by liquid nitrogen spray cryosurgery in a number of solid or multicystic ameloblastomas of the jaws and the postoperative complications related to this treatment modality.

STUDY DESIGN

Thirty-six patients with solid ameloblastoma of the jaws were treated with curettage followed by cryosurgery. The cryotherapy consisted of hand instrumented curettage of the bone lesion followed by three freezing cycles, of 1 minute each, of the remaining bone cavity with liquid nitrogen spray. Postoperative complications were evaluated clinically and radiographically.

RESULTS

Local recurrence occurred in 11 (30.6%) patients. Excepting local recurrence, postoperative complications were frequent but not severe: wound dehiscence (5.5%), paraesthesia (5.5%), infection (5.5%), and pathologic fracture (11.1%).

CONCLUSION

Management of solid or multicystic ameloblastomas of the jaws with curettage followed by cryosurgery may decrease the local recurrence rate and also to reduce the initial indication of resection with continuity defect.