The lateral periodontal cyst. A report of 37 cases

Lateral Periodontal Cyst - A diagnostic dilemma: Report of a rare case with CBCT and histological findings

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Lateral periodontal cyst [LPC] is a rare developmental odontogenic cyst.

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It is difficult to differentiate a LPC from a cyst of endodontic origin by clinical and radiographic methods. Histopathological evaluation is the only method to confirm diagnosis.

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Usually seen in association of a vital tooth, but in this case it was seen in a non-vital tooth.

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LPC is usually seen within bone, but in this case besides Intrabony component there was a gingival presentation as a swelling.

Introduction

Lateral Periodontal Cyst (LPC) is considered as a rare developmental odontogenic cyst. It is often diagnosed as an incidental radiographic finding, presenting as a circumscribed round radiolucent area between the roots of vital teeth. LPC usually does not present any clinical features. Differentiating the origin of the lesion from an endodontic or periodontal perspective presents as clinical challenge.

Presentation of case

A female patient presented with an asymptomatic gingival swelling in the lingual aspect of mandibular anterior region. The associated tooth (#34) was endodontically treated 3 years back. A periapical radiograph showed a well-defined round radiolucency on the tooth. Cone beam computed tomography (CBCT) revealed extensive bone destruction. The lesion was surgically excised and histological examination confirmed the diagnosis of LPC. The site healed satisfactorily post-operatively. The case was followed up for a year without any recurrence seen.

Discussion

LPC is a very rare clinical entity, the diagnosis of which requires a detailed case history taking, clinical and radiographic examination are essential to get proper assessment of the pathology. It is said to originate from either the remnants of dental lamina, reduced enamel epithelium or rests of Malassez. LPC presents with a typical histological picture which ensures the confirmatory diagnosis. Surgical enucleation with thorough curettage is the treatment of choice.

Conclusion

By reporting this rare case, we would like to stress to clinicians that there are a wide range of cysts and anatomic structures are present in the canine-premolar region of mandible of which LPC is a rare possibility.

Lateral Periodontal Cyst Treated with Enucleation and Guided Bone Regeneration: A Report of a Case and a Review of Pertinent Literature

Lateral periodontal cyst (LPC) is an uncommon developmental odontogenic cyst arising on the lateral surface of tooth roots. Commonly reported in mandibular canine-premolar or maxillary anterior regions, it presents as a well-circumscribed or tear drop-shaped radiolucency with a sclerotic border. Associated teeth are asymptomatic and vital, and roots may be displaced without resorption. Histopathologically, cystic lining resembles reduced enamel epithelium along with glycogen-rich clear cells and epithelial plaques. Unilateral variant of LPC has low recurrence and is managed by enucleation. A 43-year-old male patient reported with asymptomatic swelling in the left mandibular canine and first premolar region. Both teeth were vital, and radiographs revealed well-circumscribed radiolucency between the roots. Following consent, surgical enucleation and guided bone regeneration (GBR) with xenograft and resorbable collagen membrane were done under local anesthesia. The immediate postoperative period was uneventful, and complete bone fill of cystic cavity and healing of periodontal tissues was observed after a one-year follow-up. Histopathologic examination confirmed the diagnosis. LPC should be a differential diagnosis in cystic lesions lateral to the surface of a tooth and without any associated inflammation. Based on this case report, unicystic LPC can be successfully managed through surgical enucleation with GBR for better periodontal healing.

Periodontal regenerative management of residual tunnel osseous defect results from the enucleation of lateral periodontal cyst in anterior maxilla: A rare case report

The lateral periodontal cyst (LPC) is a nonkeratinized, noninflammatory developmental cyst occurring adjacent or lateral to tooth root. It is a relatively uncommon lesion found in the maxillary incisors and found mostly in adults during 5^th to 7^th decades. In this case, 45-year-old male patient reported with occasional mild discomfort between left maxillary central and lateral incisor region since 1 year. Interproximally, a well-defined round radiolucent area with corticated borders was determined radiographically between vital tooth #21 and #22. Preliminary diagnosis of LPC was established based on clinical and radiographical findings. Following enucleation of the lesion, an anticipated residual tunnel osseous defect was observed, which was managed successfully utilizing bone graft and guided tissue regeneration-assisted technique. Cystic tissue removed was examined histologically; hematoxylin- and eosin-stained sections showed features suggestive of LPC. Complete healing of tunnel defect was achieved at 1 year follow-up.

Suspected Lateral Periodontal Cyst Presenting Concurrently with Canine Acanthomatous Ameloblastoma in a 2-Year-Old Standard Poodle

Lateral periodontal cysts (LPCs) are odontogenic epithelial cysts composed of nonkeratinized epithelial cells that are in the category of developmental cysts, rather than inflammatory cysts. Lateral periodontal cysts are rare both in people and domestic animals; they are associated with vital teeth and located lateral to a tooth root. Lateral periodontal cysts are typically asymptomatic lesions that are characterized radiographically as a unilocular lucency with well-defined corticated borders. Canine acanthomatous ameloblastoma (CAA) is the most common odontogenic neoplasm in dogs and rarely presents as a cystic lesion. This case report describes the diagnosis and treatment of a cyst that occurred as a swelling apical to a gingival mass that was diagnosed histologically as CAA. Surgical management by conservative gingivectomy, cyst enucleation, and bone grafting was an effective treatment in this patient.

Odontogenic Cysts and Neoplasms

This article reviews a myriad of common and uncommon odontogenic cysts and tumors. The clinical presentation, gross and microscopic features, differential diagnosis, prognosis, and diagnostic pitfalls are addressed for inflammatory cysts (periapical cyst, mandibular infected buccal cyst/paradental cyst), developmental cysts (dentigerous, lateral periodontal, glandular odontogenic, orthokeratinized odontogenic cyst), benign tumors (keratocystic odontogenic tumor, ameloblastoma, adenomatoid odontogenic tumor, calcifying epithelial odontogenic tumor, ameloblastic fibroma and fibroodontoma, odontoma, squamous odontogenic tumor, calcifying cystic odontogenic tumor, primordial odontogenic tumor, central odontogenic fibroma, and odontogenic myxomas), and malignant tumors (clear cell odontogenic carcinoma, ameloblastic carcinoma, ameloblastic fibrosarcoma).

Odontogenic Cysts and Tumors

This article presents various odontogenic cysts and tumors, including periapical cysts, dentigerous cysts, odontogenic keratocysts, orthokeratinized odontogenic cysts, lateral periodontal cysts, glandular odontogenic cysts, ameloblastomas, clear cell odontogenic carcinomas, adenomatoid odontogenic tumors, calcifying epithelial odontogenic tumors, squamous odontogenic tumors, ameloblastic fibromas, ameloblastic fibro-odontomas, odontomas, calcifying cystic odontogenic tumors, and odontogenic myxomas. The authors provide an overview of these cysts and tumors, with microsopic features, gross features, differential diagnosis, prognosis, and potential diagnostic pitfalls.

Odontogenic Cysts - An Overview

This article aims to discuss the clinical features, radiological assessment, histopathology and management of a variety of odontogenic cysts. It also highlights the reclassification of odontogenic keratocysts to keratocystic odontogenic tumours.

Pediatric Odontogenic Cysts of the Jaws

Odontogenic cysts represent a common form of pathology of the jaws, and the natural history, clinicopathologic findings, and appropriate management strategies are important to the oral and maxillofacial surgeon. Odontogenic cysts in the pediatric populations are important pathologic entities given their potential impact on the growth and development of the maxillofacial complex. Inappropriate management strategies can severely affect the form and function of the growing child. Categorizing pediatric odontogenic cysts into inflammatory or developmental causes provides a convenient way of conceptualizing these various entities and helps facilitate the appropriate diagnosis and the subsequent management.

Treatment of lateral periodontal cyst with guided tissue regeneration

Lateral periodontal cyst (LPC), originated from epithelial rests in the periodontal ligament, is a noninflammatory cyst on the lateral surface of the root of a vital tooth. LPC is generally asymptomatic and presents a round or oval uniform lucency with well-defined borders radiographically. In this case report, clinical, histological and radiographical findings and periodontal treatment of 32-year-old female patient, who was referred to Department of Periodontology Clinic of Faculty of Dentistry, Marmara University with a painless hyperplastic lesion on the distobuccal site of the tooth number 12, were presented. The tooth number 12 was vital and a well-defined round radiolucent area with corticated borders was determined radiographically. Preliminary diagnosis was LPC based on clinical and radiographical findings. Mechanical periodontal treatment consisted of oral hygiene instructions, scaling and root planing was applied and flap operation was performed to gain access to the lesion. Following enucleation of the lesion, alveolar bone destruction shaped as a tunnel from labial to palatinal site was observed. The bone cavity was grafted with bovine-derived xenograft, followed by placement of a resorbable collagen membrane. Tissues removed from of the lesion were examined histologically. Hematoxylen-eosin stained sections showed vasculature granulomatous structure underlying squamous epithelium, and destructed bone spaces, all of which were consisted with LPC. Acceptable clinical healing was achieved at 6 months follow-up period. Satisfactory clinical and radiographical outcome can be achieved in the treatment of LPC using regenerative periodontal approach.

Benign cysts and tumors of the paranasal sinuses

To thoroughly understand the biology of any lesion and render the appropriate management, clear and accurate definitions are paramount. For benign cysts and tumors of the oral maxillofacial region, an accurate depiction of these lesions needs to be elucidated to provide both the treating surgeon and the patient with a clear understanding of the course of treatment and the outcome.

Multifocal lateral periodontal cysts: a report of 4 cases and review of the literature

Lateral periodontal cyst (LPC) is a developmental jaw cyst of odontogenic origin. It has characteristic histopathologic features that are identical to those seen in the peripherally occurring gingival cyst of adults (GCA). The polycystic variant of LPC is termed the botryoid odontogenic cyst (BOC). The histogenetic origin of LPC is probably the rests of dental lamina in the alveolar bone. In the case of BOC, it might be that several adjacent epithelial rests simultaneously undergo cystic change and eventually form a polycystic lesion. Few previous examples of multifocal occurrence of LPC can be found in the literature. We report an additional 4 patients with this rare presentation of multiple, separate LPCs, and review the literature on this topic.

Lateral periodontal cyst: a case report and literature review

Background

The lateral periodontal cyst is considered a developmental odontogenic cyst with unusual occurrence. In most cases it is preliminary diagnosed as a radiographic finding, presenting as well circumscribed or as a round or teardrop-shaped radiolucent area. Due to its location it can easily be misdiagnosed as a lesion of endodontic origin. Final diagnosis should be based on histopatological examination. The purpose of this paper is to report a classic case of lateral periodontal cyst located in the anterior region of mandible and to review the relevant literature which describes the clinical, radiological and histopathological features of lateral periodontal cysts.

Methods

A 50 years female patient complained of an asymptomatic gingival swelling in the region between the left mandibular lateral incisor and canine. Radiographic examination revealed a well circumscribed radiolucency with approximately 0.5 cm diameter with a radiopaque margin between the roots of the left mandibular lateral incisor and canine. The adjacent teeth had vital pulp.

Results

A total enucleation of the lesion was performed, and intraoperative examination showed a single lesion with no communication between the cyst's cavity and the oral environment. Histological examination revealed that the lesion was "lateral periodontal cyst of developmental origin". There was no recurrence or complications for 24 months follow-up.

Conclusions

The lateral periodontal cyst can be considered in the differential diagnosis when a radioloucent lesion appears adjacent to the roots of vital teeth. The treatment of choice is surgical removal and subsequent histological evaluation to confirm the diagnosis. Relapses are infrequent.

Lateral periodontal cyst: report of case and review of the literature

BACKGROUND

As the lateral periodontal cyst (LPC) is an unusual odontogenic cyst, most papers are single case reports or series with a limited number of cases, with few large series. The aim of this study is to report an additional case of LPC, emphasizing the clinical, radiographic, and histopathological features, differential diagnosis, and review of 264 cases reported in the English-language literature.

CASE REPORT

A 51-year-old male patient presented with a well-delimited, radiolucent, mandibular lesion, located between the roots of the right lower lateral incisor and canine and evidenced during routine radiographic examination. A surgical excision was performed. Microscopically, there was a cystic cavity lined by simple squamous epithelium, compatible with LPC.

DISCUSSION

LPC is an unusual odontogenic cyst and presents a marked predilection for occurring in the mandible between the roots of canines and premolars. Accurate clinical and imaging exams should be performed for a correct approach and diagnosis.

Gingival cyst of the adult: regenerative therapy of associated root exposure. A case report and literature review

BACKGROUND

The gingival cyst of the adult (GCA) is an uncommon developmental cyst of odontogenic origin most frequently seen near mandibular canines and premolars and is routinely treated with excisional biopsy. This article presents a case of a GCA treated with a combined regenerative approach and reviews the GCA literature with an emphasis on the clinical aspects of this lesion.

METHODS

A 54 year-old man presented for treatment of generalized severe chronic periodontitis. Clinical examination revealed a cystic lesion in the gingiva of the mandibular canine-premolar area. Radiographs revealed a well-defined radiolucency in the coronal one-third of the tooth roots. Surgical enucleation of the lesion revealed root exposure of the second premolar. Because of the anatomy of the lesion-associated defect, regenerative treatment, using a combination of freeze-dried bone allograft and a collagen membrane, was considered the therapeutic approach of choice.

RESULTS

The biopsy revealed histologic features consistent with a GCA. Clinical and radiographic examinations 1 year post-surgery indicated uneventful soft tissue healing and bone fill of the initial defect. The review of the literature revealed only one other case of root exposure associated with GCA and no previous report of regenerative therapy.

CONCLUSIONS

In rare instances, a GCA lesion may result in tooth-root exposure. In such cases, a combined regenerative treatment approach may be used to achieve resolution.

Use of guided tissue regeneration in the treatment of a lateral periodontal cyst with a 7-month reentry

BACKGROUND

The lateral periodontal cyst (LPC) is an unusual cyst of odontogenic origin, most frequently encountered in the mandible between the roots of canines and premolars. The most common treatment for LPC is surgical enucleation. This article reports a case of an LPC treated with guided tissue regeneration (GTR) and bone allograft.

METHODS

A 74-year-old woman presented for periodontal examination. Radiographs revealed a cystic lesion with LPC characteristics. After surgical incisions and flap reflection, the cyst was removed and sent for biopsy. Because of the anatomy of the resulting intrabony defect, GTR was considered the ideal treatment.

RESULTS

The biopsy revealed the histologic features of an LPC. Radiographs at 7 months post-treatment indicated bone fill of the initial defect. Although some attachment loss occurred, the reentry demonstrated a high percentage of bone fill of the defect after 7 months.

CONCLUSION

Depending on the anatomy of the defect left after the removal of an LPC, GTR, along with bone grafting, can be a very useful tool for its treatment by reducing the attachment loss observed after simple enucleation of the cyst.

Range and demographics of odontogenic cysts diagnosed in a UK population over a 30-year period

BACKGROUND

The aim of this study was to determine the range of all histologically diagnosed odontogenic cysts along with age range, sex distribution and site of presentation over a 30-year period.

METHODS

All entries for odontogenic cysts occurring during 1975-2004 inclusive were retrieved and analysed for demographic data.

RESULTS

A total of 55,446 specimens were received, of these 7121 (12.8%) specimens were diagnosed as odontogenic cysts. Radicular cyst was the most common diagnosis (52.3%), followed by dentigerous cyst (18.1) and odontogenic keratocysts (11.6%).

CONCLUSIONS

Our study provides demographic data on a large series of odontogenic cysts in a European population. This is one of the largest series reported to date. Cysts such as the paradental cyst have a predilection for certain ages, sexes and sites. Odontogenic keratocysts and glandular odontogenic cysts have a marked propensity to recur as well as behave aggressively. It is essential that such lesions are detected as early as possible to minimize any necessary surgery.

Inflammatory paradental cyst (IPC) in the mandibular premolar region in children

OBJECTIVES

We investigated the occurrence of inflammatory paradental cysts (IPC) in the mandibular premolar, and demonstrated the points of difference with regard to diagnostic features between IPC and dentigerous cysts (DC).

MATERIAL AND METHODS

We analyzed the radiographs and histology of 60 cases with a cystic lesion associated with inflammation in the mandibular premolar region based on diagnostic criteria as IPC.

RESULTS

In 4 out of 60 cases, we diagnosed the 4 cysts as IPCs in the mandibular premolar region, and recognized that one form of IPC was similar to a mandibular infected buccal cyst. The other 56 non-IPC cases were diagnosed as DC. On the IPCs, the permanent tooth normally erupted in all 4 cases after treatment, but in one case, the IPC recurred.

CONCLUSIONS

The present investigation suggested that we might have misdiagnosed IPCs in the mandibular premolar region as DC to date. It is important to consider the differences between IPC and DC with regard to the causes of recurrence during treatment of IPC.

Ameloblastoma of the mandible: a case report

This report describes the case of a 60-year-old male who presented with a radiolucent lesion between his mandibular right premolars. The original radiographic diagnosis was a lateral periodontal cyst, but surgery produced biopsy material that proved to be an ameloblastoma. A discussion on developing a differential diagnosis is presented.

Osseous repair of a lateral periodontal cyst

THE LATERAL PERIODONTAL CYSTS is a slow-growing radiolucent, developmental lesion occurring most frequently in males during the sixth decade. As part of the differential diagnosis, it must be distinguished from the collateral keratocyst and the gingival cyst of adults as well as other entities. Speculation remains as to the lateral periodontal cyst's developmental origin. Whether it is from reduced enamel epithelium, remnants of dental lamina, or cell rests of Malassez remains to be determined. The following longitudinal case report describes the review of literature and clinical and histologic findings as well as unusual treatment of a through-and-through perforating lateral periodontal cyst. Due to the large bony defect left after the cyst's removal, a decalcified freeze-dried bone graft was placed to close the defect. The repair of the lesion was followed for 30 months.

The buccal bifurcation cyst: a prospective study of treatment outcomes in 44 sites

OBJECTIVE

The clinical, radiographic, and histologic features of the mandibular buccal bifurcation cyst were studied to further define this lesion. The treatment and outcomes were also analyzed.

STUDY DESIGN

This prospective study, which spanned 3 years, included 32 patients. Their ages ranged from 5.5 to 11 years (mean of 7.5). A total of 44 buccal bifurcation cysts were treated solely with enucleation, and patients were followed up for 2.5 to 3 years.

RESULTS

All lesions were located at the buccal bifurcation of the mandibular first molar. Tilting of the buccal cusps, causing prominence of the lingual cusps, occurred in 75% of the cases. The lesion extended from the buccal bifurcation to the tooth apex in 81.2%, and a periosteal reaction on the lateral surface of the mandible adjacent to the cyst was noted in 68.8% of the cases. All of the 44 histologic reports were nonspecific, but showed a cyst lining of stratified squamous epithelium with chronic inflammation. Microbiology consisted of mixed oral flora. Complete radiographic healing in all sites without recurrence was noted in 2.5-year follow-up. The periodontal pocket depth around all the involved teeth was normalized. No loss of the mandibular first molars occurred.

CONCLUSIONS

The mandibular buccal bifurcation cyst is a distinct site-specific and age-specific clinical entity treatable by enucleation without tooth extraction.

Lateral periodontal cyst. Multifactorial analysis of a previously unreported series

The objective of the present study was to review a series of 23 lateral periodontal cysts and 2 botryoid odontogenic cysts retrieved from the files of the State University of New York at Buffalo (SUNY) Oral Pathology Biopsy Service for epidemiologic characteristics as well as radiographic findings, clinical presentation, histopathologic features, and management. This study corroborated some previously established characteristics of the lesion but also revealed some surprising aberrations. A significant difference in the age range and mean age by gender was detected with the Student's t test within this population at the 0.05 level. The classic presentation of a lateral periodontal cyst seems to be that of an asymptomatic, small, ovoid, well-corticated radiolucency that occurs in an interradicular locus in the mandibular premolar segment of a middle-aged man. However, lateral periodontal cysts may manifest with pain and cause cortical perforation, may present as large expansile radiolucencies, may arise in the maxillary molar segment, and may develop in young females. Because of the tendency for aggressiveness of other lesions that may present with a similar picture, it is important to establish the final diagnosis of lateral periodontal cyst on a histologic basis in conjunction with the clinical and radiographic findings.

Odontogenic keratocyst as periradicular radiolucency in the anterior mandible: two case reports

The differential diagnosis of periradicular radiolucencies is broad. Unusual clinical or radiographic features or failure to resolve after quality root canal treatment should be viewed with suspicion and a biopsy specimen should be submitted for histologic examination. Two cases are reported in which the presence of radiolucent lesions could have been mistaken for those of pulpal origin but were subsequently found to be odontogenic keratocysts.

Glandular odontogenic cysts. Diagnosis and treatment

Four cases of glandular odontogenic cyst are reported. Review of these and 13 previously reported cases indicates that they present as slowly growing, painless, radiolucent swellings with a predilection for the anterior part of the mandible. An incisional biopsy is essential to establish a definitive preoperative diagnosis. The unpredictable and potentially aggressive nature of these lesions is suggested by their extensive nature, penetration of cortical bone, locally invasive potential, and high incidence of recurrence after conservative treatment. In view of this behavior we suggest en bloc excision and primary reconstruction to ensure cure and reduce the operative morbidity.

Glandular odontogenic cyst: analysis of cytokeratin expression and clinicopathological features

The glandular odontogenic cyst (GOC) is a rare odontogenic cyst which is still controversial in regard to classification, terminology, and origin. The first Japanese case of GOC is reported. Immunohistochemical examination for expression of cytokeratins and epithelial membrane antigen by monoclonal antibodies suggested that the lining epithelium was of odontogenic origin with metaplastic mucus-laden cells. We have reviewed the literature and compared the clinicopathological findings of the reported case of GOC with those of botryoid odontogenic cysts (BOC). The anatomical location, age range, and sex of GOC cases were very similar to those of BOC. GOC appears to be a multiocular and mucoepidermoid variant of non-keratinizing odontogenic cysts, which also includes BOC. GOC should be separated from the other types of odontogenic cyst and central mucoepidermoid tumours of salivary gland origin.

The lateral periodontal cyst: an update

Lateral periodontal cysts account for 0.8% of all jaw cysts seen in our department. Published reports have indicated that they occur most frequently in the 5th to 7th decades, that there is a male preponderance and that they are located mainly in the mandibular canine-premolar region. In our own series of 20 cases, 10 were found in the anterior maxilla. We have distinguished unicystic and multicystic (including botryoid) varieties. They were lined predominantly or exclusively by thin reduced enamel epithelium-like tissue which contained many clear cells and epithelial thickenings referred to as plaques. Glycogen was present in the epithelium of two-thirds of our cases although not exclusively in the clear cells, many of which showed no positivity. Two of our examples of the botryoid variety were different histologically, being lined predominantly by non-keratinizing stratified squamous epithelium with crowded and pyknotic nuclei and no clear cells. One case contained melanin while another showed epithelial crypt formation and superficial palisaded low columnar cells as seen in the glandular odontogenic cyst. This raised the question of whether the latter may form part of the clinicopathologic spectrum of lateral periodontal cyst. The histogenesis of lateral periodontal cysts is uncertain but we favour origin from reduced enamel epithelium.

The lateral periodontal cyst. A histopathological and radiographic study of 32 cases

The lateral periodontal cyst is a developmental odontogenic cyst usually found in the premolar area of the lower jaw. The clinical, radiographic and histopathological features of 32 previously unreported lateral periodontal cysts were reviewed. In four cases the follow-up, which extended over several years, was also studied. Different theories of pathogenesis are discussed.

Unusual jaw-bone cysts

Four cases of unusual types of jaw-bone cysts (paradental, lateral periodontal/botryoid type, sialo-odontogenic, and intraosseous dermoid cyst) are reported. Radiographic and histopathologic features are described. Current literature is reviewed with special attention given to radiographic, histogenetic, and histopathologic aspects of these entities.

Lateral periodontal cyst. Review of the literature and report of a case

The lateral periodontal cyst is a rare odontogenic cyst of developmental origin. It occurs on the lateral periodontal region of a vital tooth and has specific histologic features. In this paper a case of a lateral periodontal cyst is presented and cases previously reported in the literature are reviewed. The present case concerns a 50-year old woman who presented for an asymptomatic gingival swelling of the left canine mandibular region of 2 month's duration. X-ray examination showed a well circumscribed radiolucency with a radiopaque margin lying between the roots of the lateral incisor and canine. The associated teeth were vital. Enucleation of the lesion was performed. The histologic examination of the specimen showed a cyst lined by thin non-keratinized epithelium with focal thickenings containing clear cells.

Lateral periodontal cysts. Clinical, radiographical and histopathological findings

21 lesions, clinically and radiographically diagnosed as lateral periodontal cysts (LPC), were retrospectively studied. The majority of the lesions were symptomless and were located in the premolar-canine-incisor region and predominantly in the mandible. 15 cases had the typical lining consistent with the diagnosis LPC. Three lesions were odontogenic keratocysts and 3 were inflammatory cysts. It was concluded that cysts in a lateral periodontal position are usually LPC but the diagnoses of keratocyst and inflammatory cyst must be considered.

The inflammatory paradental cyst

The inflammatory paradental cyst has previously been described as the collateral inflammatory cyst, the inflammatory lateral periodontal cyst, the paradental cyst, or the mandibular infected buccal cyst. Clinical, radiographic, and histologic features of 29 inflammatory paradental cysts diagnosed over a 5-year period were studied. The cysts occurred in relation to a partly or fully erupted tooth with a vital pulp. Twenty-seven of the cysts were located in the mandible and the remaining two in the maxilla. The mandibular cysts were in all cases associated with a molar. The observation that the cysts are diagnosed within a few years after tooth eruption and the demonstration of a statistically significant difference (p = 0.001) in age distribution and in the type of tooth involved suggest that eruption is important for the development of the cysts. The consistent finding of a hyperplastic, nonkeratinized stratified squamous epithelium with an intense inflammation in the connective tissue is in accordance with the hypothesis that inflammation is important for the development of these cysts.

Inflammatory paradental cysts in the globulomaxillary region

Cysts located in the maxilla between the roots of an erupted lateral incisor and a canine were studied. Radicular cysts were excluded by the prerequisite of a positive pulp vitality test in both adjacent teeth, and odontogenic keratocysts were excluded by histologic examination. In the period from 1971-1987, 8 cysts were found which fulfilled the criteria for inclusion. The average age of the patients was 18.8 yr. All cysts were lined by a hyperplastic non-keratinized stratified squamous epithelium and there was always a heavy infiltrate of inflammatory cells in the connective tissue. The clinical and histologic features were similar to those previously reported for inflammatory paradental cysts (IPC) in the mandible. Therefore, it seems justified to suggest that some of the previously described globulomaxillary cysts are in fact IPCs.

A botryoid odontogenic cyst with multiple recurrences

A botryoid odontogenic cyst (BOC) which recurred 4 times over a period of 9 years is presented. Immunocytochemical comparison of cytokeratin composition of the cyst epithelium with that of the overlying oral epithelium showed distinct differences. The cyst epithelium expressed keratins typical of both simple and nonkeratinizing squamous epithelia. The keratin profile of BOC is in line with previous findings on odontogenic epithelia, thus confirming its odontogenic origin.

Recurrent botryoid odontogenic cyst (lateral periodontal cyst)

The terms botryoid odontogenic cyst and lateral periodontal cyst have both been used to describe a histologically distinct type of cyst characterized by a thin epithelial lining exhibiting focal thickenings or plaques. The cyst reported herein is a well-documented example of this type of cyst, which exhibited persistent and recurrent behavior.

Two cystic lesions with features of both the botryoid odontogenic cyst and the central mucoepidermoid tumour: sialo-odontogenic cyst?

Two cases are reported with identical clinical, radiographical and histological features. These features share a combination of the botryoid odontogenic cyst and a central mucoepidermoid tumour, and it is suggested that the term sialo-odontogenic cyst be adopted for such lesions to avoid confusion and mismanagement.

Botryoid odontogenic cyst

Three previously unreported cases of botryoid odontogenic cyst, one of which recurred 9 years after initial surgical removal, are presented. The botryoid odontogenic cyst has a predilection for occurrence in the mandibular canine-premolar region and in persons over the age of 50 years. Periodic radiographic postoperative evaluations are recommended for these lesions, since the possibility of recurrence might be enhanced by their polycystic nature.

A radiolucent lesion adjacent to the roots of the mandibular right first and second premolars

A distinct odontogenic cyst of developmental origin, the lateral periodontal cyst has characteristic clinical, radiographic, and histopathologic findings. In addition to inflammatory lesions, lateral periodontal cysts may appear similar radiographically to an ameloblastoma or odontogenic keratocyst in its early stage; therefore, clinical and histologic correlations are necessary to establish the diagnosis and ensure proper treatment.