Cyst-like lesion of a developing tooth induced by mandibular fracture

A dentigerous cyst-like formation in the lower canine region caused by mandibular fracture in a 10-year-old boy is reported. His medical history revealed that he had been unconscious for about 2 weeks after traumatic head injuries sustained in a traffic accident, and a complicated mandibular fracture had been left untreated until his dentist diagnosed the lesion. Eleven months after trauma, a dentigerous cyst measuring 20 mm in diameter was found in the fracture area. The lesion was enucleated and the boy's postoperative recovery was uneventful. The mass completely enveloped the developing canine, and epithelial cells proliferated into the connective tissue. However, there was no distinct epithelial lining. Small round cell infiltrations and several vessels with thrombosis were noted in the cyst wall. The cause of cyst formation was considered to be infection of the canine tooth bud and the surrounding soft tissue.

[Eruption cyst]

The eruption cyst is an uncommon type of dentigerous cyst. It may be seen in deciduous or permanent dentition. Three cases of eruption cysts are reported and the subjects are discussed. Eruption cysts are associated with erupting teeth and are usually larger than dental lamina cysts, which is the main differential point between the two types of oral lesions. Eruption cysts can be seen to be different from the dentigerous cyst by the clinical features and dental radiograph surverys. Treatment of the eruption cyst is not always undertaken immediately. However, if necessary, the most common method used has been the removal of a portion of the tissue overlying the crown of the tooth to facilitate eruption.

New developments in selected cysts of the jaws

The number and variety of cysts that occur in the jaws are greater than those in any other part of the body. Consequently, dental practitioners must keep up with advances in this field, including the definition of new entities, such as the glandular odontogenic cyst; the deletion of the old incorrect concept of maxillofacial fissural cysts, including the globulo-maxillary cyst; and the advances in the molecular biology of established cysts, such as the dentigerous cyst and the odontogenic keratocyst.

A case of a large dentigerous cyst containing a canine tooth in the maxillary antrum leading to epiphora

A case of a large dentigerous cyst containing a canine tooth in the maxillary antrum is presented. This case is of interest due because of its extensiveness and the presence of a canine tooth in the roof of the maxillary sinus. In addition, this caused a right-sided epiphora. Enucleation of the cyst containing the ectopic tooth was made.

Morphologic analysis of odontogenic cysts with computed tomography

PURPOSE

The purpose of this study was to analyze the effects of lesion site and epithelial keratinization on the morphologic characteristics of odontogenic cysts and clarify determinate factors for cyst morphology.

MATERIAL AND METHODS

Computed tomographic images of 92 odontogenic cysts were analyzed: 31 primordial, 31 dentigerous and 30 radicular. Thirty-four cysts were located in the maxilla (6 primordial, 10 dentigerous, and 18 radicular) and 58 in the mandible (25 primordial, 21 dentigerous, and 12 radicular). Histologically, 31 cysts showed epithelial keratinization (18 primordial and 13 dentigerous). No keratinization was seen in radicular cysts. The morphologic features of cysts were assessed by measuring long length parallel to dental arch and short length vertical to it and calculating the long/short ratio. In addition, the computed tomography pattern of the cyst was classified into unilocular, lobulated, and multilocular patterns. Appearance of the sclerotic rim and surrounding cortex were classified into three and four patterns respectively to evaluate the developmental features of the cyst.

RESULTS

As a whole, the long length of the primordial cysts was statistically larger than the other two cyst groups and resulted in a larger long/short ratio. Statistical differences of CT pattern were also seen among cyst groups. There was no preference in any cyst group for the appearance of the sclerotic rim and cortex. There were statistical differences between maxilla and mandible in short axis and long/short ratio. The maxillary cysts generally showed round shapes irrespective of their histologic characteristics. A multilocular pattern was more frequent in the keratinized group of mandibular primordial cysts. In dentigerous cysts, a multilocular pattern was seen only in the keratinized group and the long/short ratio was statistically larger; cyst shape was elliptical along the long axis.

CONCLUSION

Our results demonstrated morphologic differences of odontogenic cysts caused by lesion site and keratinization. The dentigerous cyst with predominant keratinization should be included in the primordial cyst (odontogenic keratocyst) group.

Kinky hair disease with multiple eruption cysts: a case report

A rare case of kinky hair disease with multiple eruption cysts is described. Dental abnormalities include eruption cysts, delayed tooth eruption, prognathia, open bite, generalized gingival swelling, and high arched palate.

Two dentigerous cysts in the mandible of one patient. Case report

This paper reports a case of two separate dentigerous cysts in the mandible of one patient. An unusual feature was the relationship of one of the cysts to an unerupted lateral incisor. The prudence of accounting for any missing teeth in patients and the value of panoramic radiographic screening is illustrated.

Nucleolar organizer regions (AgNORs) in odontogenic cysts and ameloblastomas

The aim of this study was to determine whether nucleolar organizer regions (AgNORs) may be of value in distinguishing various odontogenic cysts from the unicystic ameloblastoma. Histological sections were prepared from fifteen cases each of odontogenic keratocyst, residual cyst, dentigerous cyst, unicystic ameloblastoma and conventional ameloblastoma. In each case intra-nuclear AgNOR dots were counted in 100 consecutive basal nuclei. Statistical comparison of the least squares means showed that those areas of unicystic ameloblastomas lined by characteristic epithelium had a significantly lower AgNOR count than the other groups (P < 0.05). The dentigerous cysts had significantly higher AgNOR counts than the residual cysts and unicystic ameloblastomas (P < 0.05). These differences may or may not be indicative of variations in metabolic, proliferative or transcriptional activity. We conclude that AgNOR counts are not of diagnostic significance and cannot be used to distinguish the various odontogenic cysts from one another nor from the unicystic ameloblastoma.

Glandular odontogenic cyst with hyaline bodies: an unusual dentigerous presentation

We present an unusual case of glandular odontogenic cyst (GOC) enclosing the crown of an impacted canine that developed in the anterior mandible in a 54-year-old woman. Microscopically, it contained numerous glandular structures and hyaline bodies in the epithelial lining. The present rare case is sufficiently distinctive to be considered a dentigerous variant of GOC.

Mast cell-derived tryptase in odontogenic cysts

Inflammatory and developmental cysts of the jaws are relatively common bone destructive lesions in the human maxillofacial skeleton but their pathogenesis is still poorly understood. In this study the role of mast cells (MC), and mast cell tryptase in particular, was evaluated in the pathophysiology of bone resorption and jaw cyst formation in different types of cysts. The distribution of MC and the amount of tryptase in histological tissue sections were determined by immunohistochemistry using monoclonal antihuman tryptase antibodies and the results were quantitated by using an image analyzing system. The amount of tryptase was further studied by Western-blotting and measurement of trypsin-like activity from the neutral salt extracts obtained from different types of jaw cysts. In contrast to control tissue, high trypsin-like activities and abundant immunoreactive tryptase were observed in the extracts of all types of cysts studied (radicular, dentigerous and keratocyst). In tissue sections the highest amount of tryptase-positive staining was observed in radicular cysts (mean 6.2% of reference area) and the lowest amount in keratocysts (mean 2.1% of reference area, P < 0.01). MC were found to be located in inflammatory cell-rich tissue areas and just beneath the cyst epithelium. Importantly, MC located at the border of bone were observed to be degranulated, indicating high activity of MC and release of tryptase at the regions of early bone destruction. Based on previous findings addressing the role of mast cell tryptase in proteolytic cascades, and the known association of MC with osteoporosis, we suggest that mast cells and mast cell tryptase may contribute significantly to jaw cyst tissue remodelling during growth of a cyst, and to the destruction of the surrounding bone, resulting in jaw cyst expansion.

Case report. Spontaneous regression of a radiolucency associated with an ectopic mandibular third molar

A dentigerous cyst is the most common cause of a pericoronal radiolucency involving an impacted mandibular third molar. Spontaneous regression of such a lucency is reported in a patient who failed to attend for surgical enucleation. Factors promoting bony healing of cysts are discussed with reference to previous case reports.

Dentigerous cyst with inflammatory etiology from a deciduous predecessor--report of a case

Dentigerous cysts arising from overlying infected predecessor teeth are very rare. This report describes one such case where extraction of the infected deciduous tooth with marsupialization led to the eruption of the premolar. Periodic radiographic evaluation is required to note and prevent recurrence and other serious complications arising from these cysts.

p53 expression in odontogenic keratocyst epithelium

The expression of p53 protein was studied in odontogenic keratocysts (OKC, 11 solitary, 5 recurrent and 6 NBCCS cysts), radicular (RC, n = 5) and dentigerous (DC, n = 5) cysts, using a panel of antibodies to p53 (clone BP53-12, clone 1801 and polyclonal CM1) and a sensitive biotin-streptavidin method on paraffin embedded sections. Of the three antibodies tested, clone BP53-12 gave the most intense and consistent nuclear staining pattern. Clone 1801 and polyclonal CM1 stained only 38% and 71% OKC linings, respectively, but not RC and DC linings. However, BP53-12+ cells were detected in the epithelial linings of all cyst types. Quantification of BP53-12+ cells was performed by manual counting and by relating cell number to unit length of basement membrane as determined by TV image analysis. BP53-12+ cell counts in solitary OKC linings (25.5 +/- 11.0 cells/mmBM) were significantly greater than those in DC (9.3 +/- 4.9 cells/mmBM, P < 0.01) and RC (6.7 +/- 2.6 cells/mmBM, P < 0.01) linings. The epithelial distribution of positive cells in OKC was predominantly suprabasal, which also varied from that of DC and RC linings (P < 0.005). There were no detectable differences in BP53-12 reactivity between the different subtypes of OKC (i.e., solitary, recurrent and NBCCS-associated OKC; P > 0.1). When data for the NBCCS-related OKC group were excluded, there was a significant correlation (r = 0.55, P < 0.01) between p53 and Ki67 labelling. To detect the presence of p53 gene mutations, genomic DNA, extracted from paraffin sections of OKC (4 solitary, 2 recurrent and 4 NBCCS cysts), RC (n = 3) and normal oral mucosa (n = 1), was subjected to a combination of polymerase chain reaction and single-stranded conformation polymorphism (PCR-SSCP) analysis for exons 5-10 of the p53 gene. Exon 4 was not analysed because of compromised DNA quality. No abnormality in banding patterns was found and all samples gave results similar to DNA from known, sequenced, normal p53 gene controls. Absence of p53 mutations within exons 5-9 was confirmed by the direct sequencing of 2 fresh frozen OKC samples (1 solitary and 1 NBCCS cyst). These results suggest that overexpression of p53 protein in OKC epithelium, detected by immunocytochemistry, is not reflected by alteration of the p53 gene and presumably reflects overproduction and/or stabilisation of normal p53 protein.

Increased elafin expression in cystic, dysplastic and neoplastic oral tissues

Expression of human leukocyte elastase inhibitor, elafin, otherwise known as skin-derived antileukoproteinase inhibitor (SKALP), was investigated in normal and abnormal oral tissues using a specific anti-SKALP rabbit antiserum. Weak staining was observed in keratinizing epithelia of normal oral mucosa but not in non-keratinizing mucosa. Increased expression was also observed in the suprabasal layers of dysplastic oral epithelia and in well-differentiated squamous cell carcinoma, but not in basal cell carcinoma. A uniform strong expression was observed in all supra-basal layers of odontogenic keratocyst epithelia, except in regions where inflammatory infiltrate was adjacent to keratocyst epithelia. In contrast, elafin expression in a small number of dentigerous cysts and ameloblastomas was more patchy. The increased levels of elafin in keratocyst epithelia and dysplastic tissue may be a cellular homoeostatic response to generate a protective barrier preventing proteolytic degradation of underlying elastic tissue.

Squamous carcinoma arising from a dentigerous cyst: report of a case

A case of squamous carcinoma arising in the lining of a dentigerous cyst is presented. This case is interesting because, clinically and radiographically, the diagnosis was unexpected. The light-microscopy examination revealed the moderately well-differentiated squamous carcinoma. The presentations of the case are discussed.

Dentigerous cysts of inflammatory origin. A clinicopathologic study

The exact histogenesis of dentigerous cysts remains unknown, but most authors favor a developmental origin from the tooth follicle. The aim of this article is to report a series of 15 dentigerous cysts that we believe to be of inflammatory origin. These inflammatory dentigerous cysts occurred in the first and early part of the second decades of life. Males were affected more frequently, and there did not appear to be any racial predilection. All of the cases involved permanent teeth: premolars in nine cases, canines in four cases, and second molars in two cases. The mandible was affected twice as frequently as the maxilla. In 13 cases, nonvital grossly carious or heavily restored deciduous teeth were associated with the cysts. Some of these teeth had been extracted before the cysts were diagnosed. In the remaining two cases, both of which involved the second permanent molars, there were no nonvital deciduous teeth, however both had concomitant proliferative periostitis. All of the cysts were moderately or intensely inflamed and were lined predominantly or entirely by nonkeratinized stratified squamous epithelium that in some cases was markedly hyperplastic and exhibited anastomosing rete ridges mimicking radicular cysts. In the majority of cases, parts of the cysts were lined with a 2 to 3 cell layer thick cuboidal epithelium that we believe was derived from reduced enamel epithelium. Rests of odontogenic epithelium frequently were evident in the cyst walls. We suggest that these cysts arose as a result of periapical inflammation from any source but usually from a nonvital deciduous tooth and spreading to involve the follicles of the unerupted permanent successors. The inflammatory exudate causes separation of the reduced enamel epithelium from the enamel with resultant cyst formation. This study proposes the existence of two types of dentigerous cysts: one developmental and the other inflammatory in nature.

p53 protein and Ki-67 reactivity in epithelial odontogenic lesions. An immunohistochemical study

Forty-five examples of epithelial odontogenic lesions (9 ameloblastomas (AB): 13 odontogenic keratocysts (OKC): 15 dentigerous cysts (DC): 6 radicular cysts (RC): and 2 odontogenic carcinomas (OC)) were immunohistochemically analyzed for the presence of p53 protein (p53P) and proliferative activity as indicated by positivity for Ki-67 antigen. p53P+ cells, detected as dense and/or faint nuclear staining, were found in 42 of the 45 odontogenic lesions examined. Dense p53P reactivity was most commonly detected in OKC, AB and OC, with other lesions generally exhibiting only weak nuclear reactivity. Numbers of Ki-67 positive cells as well as p53P+ cells were scored semiquantitatively. Although the presence/absence of densely stained p53P+ cells was broadly related to Ki-67+ cell numbers, there were no differences in p53P+ cell numbers between lesions exhibiting differences in proliferative activity. These results suggest that overexpression of p53P, rather than increased numbers of p53P+ cells, is related to proliferation in odontogenic epithelial lesions.

Dentigerous cyst: report of an unusual case

A case of dentigerous cyst in the maxillary sinus of a 16-year-old boy is reported due to its unusual presentation and extensive nature.

The small dentigerous cyst. A diagnostic dilemma

The dentigerous (follicular) cyst is recognized as one of the most common lesions of the jaws. Clinical, radiographic, histologic, and prognostic characteristics are well established for medium to large pericoronal cysts that are lined by nonkeratinized stratified squamous epithelium. However, it can be difficult, if not impossible, to distinguish between a small dentigerous cyst and a large dental follicle despite the availability of both radiographic and histologic information. Epidemiologic data derived from a comparative study of 1662 dentigerous cysts and 824 dental follicles showed considerable overlap in age distribution and site predilection and were therefore of minimal use in reaching a final diagnosis. At present, it appears that identifying a cystic cavity at the time of surgery may be the only reliable way to arrive at a definitive diagnosis when radiographic and histologic features are insufficient to distinguish between a small dentigerous cyst and a large dental follicle.

CT display of multiple dentigerous cysts of the mandible: a case report

Computerized tomographic (CT) display of a case with multiple dentigerous cysts in the mandible is presented and benefits of the CT in such cases are discussed. CT images provides 3 dimensional accurate details of the cystic lesions without any distortion and superposition. It shows the exact size, location and possible origin of the cysts as well as the extent of the bone destruction. It is considered that CT could be used as a guide in presurgical evaluation of the complex cystic lesions of the jaws.

A misdiagnosed giant dentigerous cyst involving the maxillary antrum and affecting the orbit. Case report

A case report of gigantic, previously misdiagnosed dentigerous cyst is presented. The cyst originated from an impacted upper right cuspid and its expansion involved the whole of the right maxillary sinus, the orbital floor and the lateral wall of the nose. The extent of the expansion was highlighted by the injection of contrast medium.

Quantification of PCNA+ cells within odontogenic jaw cyst epithelium

The aim of this study was to investigate the reactivity of the epithelial linings of the three major types of odontogenic cyst with a monoclonal antibody to proliferating cell nuclear antigen (PCNA; clone PC10). PCNA expression was studied in odontogenic cysts (n = 31) and normal oral epithelium (n = 10) using a biotin-streptavidin method on routinely processed paraffin sections. PCNA+ cells were counted manually and related to the length of basement membrane (mm) and the epithelial area (mm2) as determined by TV image analysis. The epithelial linings of odontogenic keratocysts (OKC; n = 11) contained the highest number of PCNA+ cells, most of which were located in the suprabasal layers. The mean value of PCNA+ cells in OKC linings (94.4 +/- 22.7 cells/mm) was similar to that of oral epithelia (80.8 +/- 20.6 cells/mm), but both were significantly higher than that of dentigerous (n = 10, 5.1 +/- 3.0 cells/mm) and radicular (n = 10, 11.0 +/- 4.1 cells/mm) cyst linings (P < 0.005). The epithelial distribution of PCNA+ cells differed between groups with the basal/suprabasal PCNA+ cell ratio in OKC linings (0.05 +/- 0.02) being significantly lower than that of normal oral epithelium (0.5 +/- 0.14), dentigerous (1.6 +/- 1.23) and radicular (1.9 +/- 1.09) cyst linings respectively (P < 0.005). These results demonstrate differences in PCNA expression between the epithelial linings of the major odontogenic cyst types, indicating differences in proliferative and differentiation processes within these lesions.