Immunoprofile of the adenomatoid odontogenic tumor.

This study was focused on the immunohistochemical profile of the adenomatoid odontogenic tumor. A Pub/Medline search revealed a number of immunohistochemical studies including cytokeratin profiles, extracellular matrix proteins, Integrins, ameloblast-associated proteins resorption regulators (RANK, RANKL), p53, PCNA, MDM2 protein, cyclin D1, Ki-67, Bcl-2 metallothionein, metalloproteinases, D56 hepatocyte growth factor, c-met, DNA methyltransferase, podoplanin, TGF-ßI, Smad-2/3, Smad-I-5/-8, Smad 4, beta- catenin, calretinin, and clonality. Careful interpretation of the findings indicates that the adenomatoid odontogenic tumor may be more of a hamartomatous than neoplastic nature.

Unicystic ameloblastoma. A review of 193 cases from the literature.

Based on a world-wide literature survey of 193 published cases of unicystic ameloblastomas (UA), data have been produced allowing the presentation of a revised concept of this much debated lesion. UA is a variant of the solid or multicystic ameloblastoma. Radiographically, the unilocular pattern is more common that the multilocular, especially in cases associated with tooth impaction. However, it is stressed that although the lesion is pathomorphologically unicystic, it will far from always produce a unilocular radiolucency. The mean age at the time of diagnosis of UA is closely related to an association with an impacted tooth. Almost 20 years separate the mean age of the 'dentigerous' variant from the 'non-dentigerous' (16.5 years versus 35.2 years) The male:female ratio for the 'dentigerous' type is 1.5:1, but for the 'non-dentigerous' type it is reversed (1:1.8). Location favours greatly the mandible (mandible to maxilla = 3 to 13:1). Between 50 and 80% of cases are associated with tooth impaction, the mandibular third molar being most often involved. The 'dentigerous' type occurs on average 8 years earlier than the 'non-dentigerious' variant. The mean age for unilocular, impaction-associated UAs is 22 years, whereas the mean age for the multilocular lesion unrelated to an impacted tooth is 33 years. Histologically, the minimum criterion for diagnosing a lesion as UA is the demonstration of a single cystic sac lined by odontogenic (ameloblastomatous) epithelium often seen only in focal areas. This simple type of UA (according to the authors' modification of the classification by Ackermann et al. (Journal of Oral Pathology 1988; 17:541-546)), is one of four UA subtypes, the others being (1) simple with intralumenal proliferations; (2) simple with both intralumenal and intramural proliferations; and (3) simple with intramural proliferations only. All four subtypes occur in both the 'dentigerous' and 'non-dentigerous' variants. The simple subtype with and without intralumenal proliferations may be treated conservatively (enucleation), whereas subtypes showing intramural growths must be treated radically, i.e. as a solid or multicystic ameloblastoma. Finally, the authors disclose areas and issues pertaining to UA that still need to be addressed.

Adenomatoid odontogenic tumour: facts and figures.

The present profile of the adenomatoid odontogenic tumour represents an update based on data collected from 1991 onwards. Our present knowledge discloses the AOT being a benign (hamartomatous), slow growing lesion which occurs in several intraosseous (follicular (F) and extrafollicular (EF)) and one peripheral variant all having identical histology. The F and EF variants account for 96 per cent of all AOT's of which 71 per cent are F variants alone. F and EF variants together are more commonly found in the maxilla than in the mandible with a ratio of 2.1:1. Age distribution shows that more than two thirds are diagnosed in the second decade of life and more than half of the cases occur within the teens (13-19 years of age). The female:male ratio for all age groups and AOT variants together is 1.9:1. The marked female predominance (around 3:1) among certain Asian populations needs further clarification. The distribution of unerupted permanent teeth found in association with the F variant shows that all four canines account for 59 per cent and the maxillary canines alone for 40 per cent. Recent findings strongly indicate the AOT is derived from the complex system of dental laminae or its remnants. Occurrence of areas of CEOT-like tissue in an otherwise "classic" AOT should be considered a normal feature within the continuous histomorphological spectrum of AOT. Immunohistochemical and ultrastructural findings have revealed that the eosinophilic deposits or "tumour-droplets" most probably represent some form of enamel matrix.

Calcifying epithelial odontogenic tumour: biological profile based on 181 cases from the literature.

The present profile of the calcifying epithelial odontogenic tumour (CEOT) is based on a literature survey of 181 published tumour cases. The CEOT is a benign, though occasional locally invasive, slow-growing neoplasm occurring as intraosseous (94%) and extraosseous (6%) variants. The intraosseous type appears radiographically as an irregular, uni- or multilocular radiolucent area containing radiopaque masses which increases in size and opacity with time. Some 60% of intraosseous CEOT are associated with an unerupted tooth (or odontoma). CEOT shows a relative frequency of 1-2%. The extraosseous variant is diagnosed slightly earlier (mean age 34.4 years) than the intraosseous type (mean age 38.9 years). Both variants have an almost 1:1 gender ratio. The intraosseous CEOT shows a maxilla:mandible site ratio of 1:2 and are mainly located in the premolar/molar region. The present authors present evidence that the CEOT originates from the complex system of dental laminae or remnants thereof. Histologically, the CEOT is characterized by the occurrence of sheets, nests and masses of polyhedral, eosinophilic epithelial cells which may show cellular abnormalities including giant cell formation and nuclear pleomorphism. Some cells increase in size and produce a homogeneous, eosinophilic, 'amyloid-like' substance which may become calcified and which may be liberated as the cells break down. The true nature of the amyloid-like material is still unresolved. Histological variants including CEOT with cementum-like components, clear-cell CEOT (15 cases reported so far), CEOT-containing Langerhans' cells, combined epithelial odontogenic tumour (CEOT/AOT) and CEOT with myoepithelial cells are discussed in detail. In view of the relatively indolent biological behaviour of the CEOT, mutilating procedures, such as wide resection or hemisection of the mandible, seem unwarranted. Enucleation with a margin of macroscopically normal tissue is, therefore, the recommended treatment for CEOT involving the mandible. Maxillary CEOT should, however, be treated more aggressively, as they tend to grow more rapidly and do not usually remain well confined. Generally, recurrences are rare. Five years is considered the absolute minimum follow-up period. The survey has revealed only one well-documented case of a mandibular CEOT in a 75-year-old man showing features of malignancy.

Mixed odontogenic tumours and odontomas. Considerations on interrelationship. Review of the literature and presentation of 134 new cases of odontomas.

Based on a world-wide literature survey of published cases of "mixed odontogenic tumours" (ameloblastic fibroma, fibrodentinoma and fibro-odontoma) and complex/compound odontomas (including 134 own cases of odontomas) the authors present data showing the complex nature of these lesions. The authors suggest the following work hypothesis regarding the pathogenesis and relationship between the "mixed odontogenic tumours" and the odontomas. The tumours develop along two separate lines: (I) the neoplastic line comprising only one tumour, the ameloblastic fibroma (AF) and the closely related ameloblastic fibrodentinoma (AFD). (II) The hamartomatous (or the developing complex odontoma (DCO) line comprising: (1) The AF (and AFD). Differences in age and biological behaviour indicate that some AF are true benign neoplasms, whereas others are hamartomas presenting the first stage in the DCO-line. (2) The AF-O represents the second stage of the DCO-line developing into (3) the fully mineralized complex odontoma. Lastly, the authors suggest that the compound odontoma should be considered not as an alternative final stage to the complex odontoma but rather as a malformation (with a high degree of histomorphological differentiation) pathogenetically closely related to the process producing hyperodontia, "multiple schizodontia" or locally conditioned hyperactivity of the dental lamina.

Desmoplastic ameloblastoma (including "hybrid" lesion of ameloblastoma). Biological profile based on 100 cases from the literature and own files.

The profile of the desmoplastic ameloblastoma (DA) is presented, based on a survey of 100 cases. DA is a benign, locally invasive variant of the intraosseous, infiltrative ameloblastoma (IA). Radiologically, the DA shows ill-defined borders with a soap bubble appearance. The finding of a mixed radiolucency-radiopacity in 52% of the cases often leads to a preoperative diagnosis of a fibro-osseous lesion. Association with an unerupted tooth is not a typical finding. The DA accounts for 4-13% of all ameloblastomas. The over-all average age is 42.9 years, higher for males (45.9 years) than for females (39.7 years). Thus, the DA occurs at a slightly higher age than the intraosseous ameloblastoma (37.4 years). The male/female ratio is 1:1. The maxilla/mandible ratio is 1/0.9 as opposed to 1/5.4 for the IA. Seven maxillary tumours involved an entire quadrant and 15 maxillary and mandibular tumours crossed the midline of the jaws. Pathogenetically, it seems that the DA is derived from the same sources as the IA, and extra-osseous sources do not seem to play a role. Histologically, the DA reveals the following morphological characteristics: the odontogenic epithelium occurs as irregular, stellate or follicular islands and cords, the center often appearing hypercellular with spindle-shaped or squamatoid cells. Peripheral columnar or cuboidal cells rarely reveal an ameloblast-like appearance. Thus, there are only vague tendencies to mimic a follicular ameloblastoma with acanthomatous features. The most striking feature separating the DA from IA is to be found in the tumour stroma: in DA there is extensive stromal desmoplasia with an abundance of thick collagen fibres that seem to compress the epithelial islands. Nine cases of so-called "hybrid lesion of ameloblastoma" where areas of IA coexist with areas of DA are surveyed in addition to the 100 cases of DA. No conclusions can be drawn about the biological profile of this variant due to the insufficient number of cases.

Verruciform xanthoma--biological profile of 282 oral lesions based on a literature survey with nine new cases from Japan.

The biological profile of oral verruciform xanthoma (VX) is presented based on a world-wide literature survey of 282 cases. From 1979 onwards, extraoral cases have also been reported. This rare, harmless lesion with a sessile or pedunculated base is a red/pink, papillary/granular/verrucous mucosal growth, occurring in females (mean age, 54.9 yrs) and males (mean age, 44.2 yrs) in a female:male ratio of 1:1.1. The most common location is by far the gingival margin and other areas of the masticatory oral mucosa. Comparison between 173 non-Japanese and 109 Japanese patients with oral VX showed few discrepancies in epidemiological data, indicating only few significant ethnic differences between the two cohorts. Histomorphologically, the epithelium covering the lesion can be divided into three groups: (A) a verrucous, (B) a papillary and (C) a flat pattern. The hallmark of all VX, irrespective of the lesion being intra- or extraoral is, however, the presence of vacuolated, foam or xanthoma cells which ultimately replace the connective tissue between the epithelial ridges. The xanthoma cells have been shown to be cells of the monocyte/macrophage lineage. The present concept of the etiology and pathogenesis of VX, including the possible viral (HPV) association is revised, based on both intra- and some extraoral cases, and it is concluded that it is still far from being clarified.

Peripheral ameloblastoma: biological profile based on 160 cases from the literature.

The present profile of the peripheral ameloblastoma (PA) is based on a literature survey of 160 published tumour cases. The PA is an exophytic growth localized to the soft tissues overlying the tooth-bearing areas of the jaws, the initial diagnosis often being fibrous epulis. In most cases there is no radiological evidence of bone involvement, but a superficial bone erosion--known as cupping or saucerization--may be detected at operation. The PA accounts for 2-10% of all ameloblastomas. The overall average age is 52.1 years, slightly higher for males (52.9 years) than for females (50.6 years). Thus, the PA occurs at a significantly higher age than the intraosseous ameloblastoma (IA; 37.4 years). The male/female ratio amounts to 1.9:1, as opposed to 1.2:1 for the IA. The male/female ratio for the Japanese cases included in this survey is 2.5:1 as opposed to that of non-Japanese cases 1.4:1. As to the location of PA, the maxilla/mandible ratio is 1:2.6. The mandibular premolar region accounts for 32.6% of all sites. Five extra-gingival lesions have been reported under the term PA. As these cases most likely represent salivary gland tumours, they are not accepted under the diagnosis of PA. The odontogenic gingival epithelial hamartoma shows clinical, histological and behavioural features almost identical to the PA, and it is discussed whether this lesion and the PA should be considered one and the same entity. Pathogenetically, two major sources are discussed: remnants of the dental lamina and the oral surface epithelium. Histologically, the PA consists of proliferating odontogenic epithelium exhibiting the same histomorphological cell types and patterns as seen in the IA. The stroma is that of a mature, fibrous connective tissue. The indolent biological behaviour dictates a conservative therapeutical approach. It is discussed whether PA is a true neoplastic counterpart of the IA or rather an odontogenic hamartomatous lesion. Six cases of malignant PA have been reported.

Chelate root filling cements: biological properties.

The purpose of this study was to test in vivo and in vitro the toxicity and the antibacterial activity of an experimental chelate cement (HN cement) using zinc oxide-eugenol cement as a reference. After subcutaneous injection of the spatulated HN cement paste in rats, it induced markedly less tissue injuries than did the zinc oxide-eugenol cement. In toxicity tests using cultures of human fibroblasts, the HN cement was found to be less toxic than the reference cement. Bacteriologically, blood agar plates inoculated with Streptococcus sanguis, Staphylococcus aureus, and the anaerobic Prevotella intermedia developed inhibition zones between 3 and 12 mm upon application of both cements. Both demonstrated marked bacteriostatic and bactericidal properties.

Age estimation from the structure of adult human teeth: review of the literature.

The literature on age estimation from the structure of adult human teeth is reviewed. Several anatomic changes of teeth have been shown to be valuable in age determination, but there is still controversy concerning the accuracy of cemental annulation. It is believed that improvements in age estimation can be made using direct measurement rather than scoring systems.

Preliminary report on a new method of human age estimation from single adult teeth.

A total of 317 upper and lower third molars were randomly divided into working and control samples and used to estimate chronological age employing a method which combined multiple regression analysis of data from Gustafson's and Maples's scoring system, direct morphological measurements obtained with a Kontron image analysis system and logarithmic data transformation. The standard errors of estimate were 2.4-6.8 years in the working sample and 1.9-7.5 years when the derived formulae were tested on the control sample, respectively. Compared to previous studies, this method provides a smaller standard error of estimate from a single molar tooth. The method is presently being tested on other tooth categories, like premolars, canines and other types of molars.

The desmo- and osteoplastic ameloblastoma. Histologic variant or clinicopathologic entity? Case reports.

Two cases of desmoplastic ameloblastoma (DA) are presented, bringing the total number of reported cases to 29. One case of the so-called "hybrid lesion" is added to the presentation. Immunohistochemical studies indicate that the desmoplasia is caused by active de novo synthesis of extracellular matrix proteins. Moreover, the DA may also show osteoplasia, and this probably explains the characteristic radiographic appearance of many DAs, i.e. the occurrence of both radiolucent and radiopaque changes, suggestive of a fibro-osseous lesion. Many more cases of DA are needed to clarify the true nature of this most interesting tumor.

Clear cell calcifying epithelial odontogenic tumor. A case report.

Clear cell variants of odontogenic tumors are rare. A case of clear cell calcifying epithelial odontogenic tumor of the mandible in a 38-year-old Caucasian male is described. This case is compared to 8 previously reported cases. The origin of clear cells in odontogenic tumors is still unknown. En bloc resection of the tumor is recommended.

Use of etorphine-acepromazine and diprenorphine in reversible neuroleptanalgesia of rats.

The death rate due to neuroleptanalgesia (0.35%) was significantly lower than for barbiturate anaesthesia (1.59%). Complications were few even when animals received multiple, repeated, anaesthesia, and depth of anaesthesia could be adjusted easily. Further, it could be reversed within minutes by the specific antagonist diprenorphine.

Prevalence of oral lesions in a selected Vietnamese population.

Clinical examination of the oral and peri-oral regions of a cohort of 550 Vietnamese living in a refugee camp in Hong Kong was conducted. They comprised 216 (39 per cent) males and 334 (61 per cent) females and their age ranged from 2 to 60 years. A positive clinical finding was observed in 14 per cent, 35 males and 43 females. The most common condition observed was periapical infection (36 per cent), either with an abscess or a sinus. Other lesions noted include mucocele (10 per cent), traumatic ulcers (9 per cent), tori, either palatal (6 per cent) or mandibular (3 per cent), lymph node enlargement (7 per cent), pulp polyp (6 per cent), angular cheilitis (4 per cent), papillomas (3 per cent), cellulitis (3 per cent) and herpes lesions (2 per cent), 7 out of 9 (78 per cent) mucoceles were found in females. No malignant lesions were noted.

Age estimation by Chinese permanent teeth with image analysis.

A total of 567 human teeth except third molars were studied to estimate age, using a combined method of multiple regression analysis of data from a scoring system, direct measurements with image analyser, and logarithmic transformation. As a result, the standard errors of estimate were 4.8-5.4 years in the working sample, and 2.9-5.4 years in the control sample respectively, by using a single tooth. By testing the formulae on forensic autopsy cases in Guang Dong and Guang Xi, (People's Republic of China), it is demonstrated that the standard error of estimate is 3.7 and 2.6 years respectively for any single tooth (incisor, canine, premolar or molar) except the third molar. Age determination from multiple teeth of the same individual has also been studied. As a result, according to the different age grouping, the standard errors of estimate ranged from 0.8 to 2.6 years (2 teeth from the same individual) and 0.6 to 2.3 years (3 teeth from the same individual). It is concluded that the method presented here is helpful in improving the accuracy of age determination from teeth.