Unsuspected small ameloblastoma in the alveolar bone: a collaborative study of 14 cases with discussion of their cellular sources

Surgical Margins for Ameloblastoma in Dogs: A Review With an Emphasis on the Future

Ameloblastoma is a benign epithelial odontogenic tumor with the capacity to aggressively invade the surrounding bone. Surgical removal of the tumor can result in extended disease-free interval (cure). However, controversy surrounds the most appropriate surgical margin required to prevent local recurrence while simultaneously minimizing morbidity. En bloc excisional surgery carries the risk of major complications such as mandibular drift, hemorrhage, and oronasal fistula formation. Conservative therapy without a safety margin reduces potential morbidity but is likely to result in local recurrence. No reliable rate, nor time to recurrence, is documented but may be as high as 91% with conservative therapy. Conversely, surgery with a 10- to 20-mm margin is associated with a 0–4.6% recurrence rate. There is no documented difference in the recurrence rate with a 10- vs. 20-mm margin. The correlation of the histologic margin with the recurrence rate following excisional surgery has not determined a required histologic safety margin. Rather, no local recurrence occurs despite narrow or incomplete margins. Thus, pathologic margins > 0 mm may be sufficient to prevent local recurrence or recurrence may be protracted. Accordingly, a narrow (5–10 mm) gross surgical margin may be the most appropriate. Additional research is required for confirmation, and only level 4 evidence on safety margins has been achieved thus far. Future work should focus on defining the extension of neoplastic cells past the demarcation of ameloblastoma on variable diagnostic imaging modalities as well as determining the recurrence rate with various surgical and histologic safety margins.

Revisiting the human dental follicle: From tooth development to its association with unerupted or impacted teeth and pathological changes

Dental follicles are involved in odontogenesis, periodontogenesis, and tooth eruption. Dental follicles are unique structures, considering that their remnants can persist within the jawbones after odontogenesis throughout life if the tooth does not erupt. Pathological changes may occur in these tissues as individuals age. The changes range from benign to life threatening. Thus, the assessment of age-related changes in dental follicles associated with unerupted teeth is of paramount importance. In this review, we summarize the physiological roles and changes in dental follicles in odontogenesis, tooth eruption, and aging, in addition to the pathological changes associated with these structures. We encourage investigators to consider this peculiar tissue as a unique model and explore its potential to clarify its importance from the viewpoints of developmental biology, tissue physiology, and pathology.

Maxillary Ameloblastoma: A Review With Clinical, Histological and Prognostic Data of a Rare Tumor

Diagnosis of odontogenic tumors can be challenging due to their rarity and diverse morphology, but when arising near the tooth, the diagnosis could be suspected. When their location is not typical, like inside the paranasal sinuses, the diagnosis is less easy. Maxillary ameloblastomas are exceedingly rare with only sparse information on their epidemiological, histological and genetic characteristics. The aim of this report is to thoroughly review the available literature in order to present the characteristics of this tumor. According to available data, maxillary ameloblastomas can occur in all ages but later than mandible ones, and everywhere within the maxillary region without necessarily having direct contact with the teeth. No sex preference has been shown. The most common histological patterns seen in this location are the follicular and plexiform ones. Maxillary ameloblastomas are locally aggressive neoplasms, thus therapy aims for excision including normal bone beyond the lesion. In contrast to mandible ameloblastomas, maxillary ones most commonly show mutations of the SMO gene. Furthermore, differential tumor diagnosis is thoroughly discussed in the present review.

Effects of aging on DNA hydroxymethylation and methylation in human dental follicles

OBJECTIVE

Despite the high frequency of impacted teeth and increased frequency of lesions in dental follicles (DF) with aging, DF age-changes remain unclear. We compared the global methylation and hydroxymethylation profiles in DF in relation to age.

DESIGN

DF associated with impacted lower third molars were obtained from 59 individuals. Global DNA methylation (5mC content) and hydroxymethylation (5hmC) were evaluated by ELISA. We tested the correlation between 5mC and 5hmC content, and the correlation of each with patients' age. The differences in age, 5mC, and 5hmC in DF from men/women, and location (left/right mandible) was tested.

RESULTS

The mean age of the 59 individuals was 19.56 ± 3.92, ranging from 13 to 31 years, and most were women (n = 39). 5hmC content and age up to 19 years were inversely correlated (Spearman's correlation coefficient=-0.552, p = 0.0003, n = 38). There was no relationship between 5hmC and 5mC content. There was no difference in the medians of age (p = 0.25), 5hmC (p = 0.33) and 5mC (p = 0.86) between men/women, nor in the medians of age (p = 0.39), 5hmC (p = 0.99) and 5mC (p = 0.22) between the left/right side of the tooth extraction.

CONCLUSION

An inverse correlation between 5hmC and age was established, with no correlation between 5mC and 5hmC content in DF. The biological meaning of such a decrease of global DNA hydroxymethylation with age in DF remains to be clarified.

Clinicopathological characteristics of desmoplastic ameloblastoma: A systematic review

The aim of the present review was to systematically present the clinicopathological data of desmoplastic ameloblastoma (DA) from articles published in the literature. A comprehensive search of the databases (PubMed, Medline, SCOPUS, Web of Science, and Google Scholar) for published articles on DA was conducted. A total of 238 cases were identified and analyzed from 76 published papers. DA showed a slight male predilection (male: female=1.07:1) with a predominance in the fourth and fifth decades of life. Mandibular involvement (52.55%) was most commonly seen with a marked tendency for the anterior region (mandible: 40.9%, maxilla: 48.07%). The size of the lesion ranged from .5 cm to 20.4 cm, with the majority of cases measuring more than 3 cm in size (53.84%). Radiologically, most of the lesions presented mixed radiolucency and radiopacity (62%), and root resorption was observed in only seven cases. The majority of the lesions showed ill-defined margins upon radiographic examination (65.78%). Most of the cases were treated with resection (78.57%), and five of the 10 recurrent cases were treated by enucleation/curettage. DA is characterized by the unique presentation of clinicopathological parameters. It is not possible to comment on its aggressive/recurrent nature and best treatment modality due to inadequate follow-up data.

An unusual case of ameloblastoma observed in the left anterior mandible

AIM

To report a small intaalveolar ameloblastoma which resembled cystic lesion, and to emphasize the value of Computed tomography (CT) in radiographic examination.

BACKGROUND

Ameloblastoma is a slow-growing, locally invasive odontogenic neoplasm that accounts for approximately 10% of all tumors detected in the jaws. Radiographically, those tumors are usually well-defined. Computerized tomography is highly recommended to confirm the diagnosis.

CASE DESCRIPTION

A 48-year-old female attended with a chief complaint of painless swelling in the left anterior of mandible, 1 month duration. In intraoral examination, non-fluctuant, immobile, approximately 1 × 1 cm in dimension, painless, swelling which had a bone-like hardness and located in the mandibular canine region was detected. Panoramic radiography revealed a well circumscribed unilocular radiolucent lesion located in the inter-radicular area of left mandibular lateral and canine teeth. In CT examination it was realized that the lesion was multilocular. Histopathological examination of the biopsy specimen was reported as ameloblastoma.

CLINICAL SIGNIFICANCE

It is extremely difficult to find such an ameloblastoma in small dimension in alvolar bone.

Intraosseous ameloblastoma with a prominent extraosseous component: pitfalls in diagnosis

For many years, gingival tumors of what appear to be peripherally located intraosseous ameloblastoma (IA) arising from the alveolar bone surface have often been confused with peripheral ameloblastoma (PA) causing resorption of the underlying bone. We analyzed a series of five cases of ameloblastoma that demonstrated a combined PA and IA architecture. The tumor commonly involved the anterior-premolar area, mostly in the maxilla and mainly in middle-aged men. The clinical presentation was an exophytic gingival mass inferior to which was a small bone defect. The predominant extraosseous component showed a papillary gross surface, reflecting the histologic proof of fusion between the submucosal tumor and the surface epithelium. In addition to the PA-like growth pattern, common to all was the presence of neoplastic destruction of the alveolar process, corresponding to an associated radiolucent lesion. This restrained component was acceptable as IA. In two cases, recurrence was observed deep in the alveolar bone with no involvement of the gingiva. These tumors appear to be IA that arose from the marginal alveolar bone and grew preferentially in the gingiva, forming a PA-like appearance. From diagnostic, therapeutic and prognostic points of view, this type of IA should not be confused with PA.

An unsuspected ameloblastoma in the subpontic region of the mandible with consideration of pathogenesis from the radiographic course

The purpose of this report is to document a case of unsuspected ameloblastoma involving the right man dibular subpontic region in a 38-year-old Cambodian female patient. This lesion was purportedly preceded by multiple radiolucencies which were diagnosed as radi cular cysts and treated a few times in the past years by enucleation followed by endodontic therapy of the affected teeth. Bridgework restoration of the partially edentulous area was performed. This case report de monstrates radiographic changes that occurred in the periods before and after the diagnosis of amelo blas to ma. The case may represent an example of radicular cysts and ameloblastoma occurring as a collision phenomenon, or the ameloblastoma may have arisen as a result of neoplastic transformation of the lining epi thelium in an inflammatory odontogenic epithelial cyst.

Diagnostically challenging epithelial odontogenic tumors: a selective review of 7 jawbone lesions

Considerable variation in the clinicopathologic presentation of epithelial odontogenic tumors can sometimes be confusing and increase the chance of misdiagnosis. Seven diagnostically challenging jawbone lesions are described. There were 2 cases of mistaken identity in our ameloblastoma file. One unicystic type, initially diagnosed and treated as a lateral periodontal cyst, showed destructive recurrence 6 years postoperatively. The other globulomaxillary lesion was managed under the erroneous diagnosis of adenomatoid odontogenic tumor and recurred 4 times over an 11-year period. This tumor was found in retrospect to be consistent with an adenoid ameloblastoma with dentinoid. The diagnosis of cystic squamous odontogenic tumor (SOT) occurring as a radicular lesion of an impacted lower third molar was one of exclusion. Of two unsuspected keratocystic odontogenic tumors, one depicted deceptive features of pericoronitis, while the other case has long been in our files with the diagnosis of globulomaxillary SOT. Two cases of primary intraosseous squamous cell carcinoma appeared benign clinically and exhibited unexpected findings; an impacted third molar began to erupt in association with the growth of carcinoma and another periradicular carcinoma showed dentinoid formation. Cases selectively reviewed in this article present challenging problems which require clinical and radiographic correlation to avoid potential diagnostic pitfalls.