Involvement of soft tissue by odontogenic keratocysts (primordial cysts)

Comparison of Five Different Treatment Approaches of Mandibular Keratocystic Odontogenic Keratocyst (OKC): A Retrospective Recurrence Analysis of Clinical and Radiographic Parameters

The odontogenic keratocyst (OKC) is a benign but locally aggressive growing lesion that infiltrates the bone and surrounding tissue. It is characterized by high rates of recurrence along with rapid growth. Different forms of partly successful treatment therapies are reported. The retrospective study at hand examined 114 patients with OKC treated over a period of 20 years. Data extracted includes gender, age, location, previous treatment for the lesion, surgery, outcome, recurrence rate and follow-up. 63.1% of the patients underwent cystectomy, 22.5% by cystectomy and carnoy solution, 7.2% by cystectomy, and curettage, 4.5% by cystostomy and 2.7% by partial resection. In this study, no significant differences could be observed regarding the surgical method. Most recurrences occurred with 91.9% in the mandible with an average size of 5.5 cm2 and increased in women. Within a mean follow-up time of 3.6 years the recurrence rate was 36.9%, on average after 36 months. Recurrences were most frequently diagnosed at the age of 31-50 (43.9%). Despite numerous studies, there is still no unanimous opinion on an effective therapy for OKC. However, precise resection of OKC can be facilitated by preoperative 3D-imaging and virtual planning.

Modified Carnoy's Versus Carnoy's Solution in the Management of Odontogenic Keratocysts-A Single Center Experience

To date, few studies have been conducted to test the effectiveness of Carnoy's (CS) versus modified Carnoy's (MC) solution for preventing the recurrence of odontogenic keratocysts, which are potentially aggressive lesions. To evaluate the efficacy of MC application, we conducted a retrospective cohort study over an 18-year period, from October 2004 to October 2022, in 122 patients treated surgically with adjunctive chemical cautery, with either CS (n = 73; median age: 30 years) or MC (n = 49; median age: 42 years), by a single surgeon. The primary outcome variables were observed recurrence and interval to recurrence. Independent variables were demographics, location, clinical presentation at baseline, adjacent tooth extraction, and bone grafting. Males predominated in both groups. No statistically significant differences were observed between the two arms in terms of recurrences in particular months, with six patients (8.2%) in the CS arm and 5 (10.2%) in the MC arm. Of the 11 recurrences, 10 were observed within the first 2 years post-surgery, with only one occurring in the 7th year of follow-up. Thus, when used as adjunctive therapy, the application of MC has an efficiency comparable to that of CS for lowering the recurrence rate of odontogenic keratocysts.

The extra-osseous odontogenic keratocyst: An anachronism?

INTRODUCTION

The aim of this study was to review the literature on extra-osseous odontogenic keratocysts, and to present the best possible approach to these lesions.

MATERIAL AND METHODS

A comprehensive literature search was performed using the strategy: (keratocyst) and (soft tissue)). A total of 25 articles were included, 20 reported on extra-osseous odontogenic keratocysts in the soft tissues of the mouth and 17 presented as gingiva cysts.

DISCUSSION

Almost all articles were published in the last 20 years and 16 even in the last 10 years. Extra-osseus odontogenic keratocysts are usually found in the cheek or present as gingiva cysts of adults. Muscle abutment of the cheek lesions is common but infiltration of muscles has also been reported.

CONCLUSION

In almost none of the reported cases was a preoperative diagnosis available. Based on the clinical presentation and available laboratory tests it is suggested to always do an aspiration biopsy to ascertain the diagnosis preoperatively. This is particularly relevant for those who appear in the soft tissues of the mouth.

Recurrence of odontogenic keratocyst in the buccal space

Odontogenic keratocyst (OKC) rarely appears in the buccal space. It is aggressive and infiltrative, and simple enucleation results in high recurrence. This case report describes an OKC located in the buccal space recurring twice in a 62-year-old man with a 25 mm diameter cystic lesion in the right pterygomandibular space. The multicystic lesion was enucleated. Subsequently, a recurrence was observed, and the gourd-shaped recurrent lesion was also enucleated. The difficulty in detaching the mass from the scar tissue resulted in the perforation of the cystic wall. Thereafter, a second recurrence was observed, and the tissue surrounding the unicystic recurrent lesion was excised. The histopathological features were consistent with those of OKC. The present case is the 11th reported case of OKC in the buccal space and the first with apparent recurrence. Since complete enucleation in the pterygomandibular space is difficult, excision along with the surrounding tissues could prevent recurrence.

A systematic review on the expression of bcl-2 in the nonsyndromic odontogenic keratocyst: should it be considered a cyst or a tumor?

The purpose of this study is to find out if the biological behavior and the capacity of the odontogenic keratocyst (OKC) in maintaining pathologic cells alive are more similar to the dentigerous cyst or to the ameloblastoma by assessing bcl-2. We searched MEDLINE, Web of Science, and Scopus for immunohistochemical studies reporting OKCs, dentigerous cysts, and ameloblastomas. Risk difference between the lesions expressing bcl-2 was the effect measure and a P value < 0.05 was considered to provide evidence to the effect estimates. OKCs have an estimated difference of 91% in the probability to express the bcl-2 over dentigerous cysts, but there is no difference in the expression of bcl-2 between OKCs and ameloblastomas. The present study demonstrated a great risk difference in the expression of bcl-2 between OKCs and dentigerous cysts and no risk difference between OKCs and ameloblastomas. OKC's growth may indirectly be attributed to the anti-apoptotic effect of bcl-2 in the cystic epithelium and not only to the increase of its intraluminal pressure. Therefore, the classification of this lesion into keratocystic odontogenic tumor should be carefully reconsidered.

Odontogenic Keratocyst: Developing a Protocol for Surgical Intervention

The aim of this study was to report the outcome of a conservative treatment protocol – “enucleation and packing open” for odontogenic keratocyst (OKC). Ten patients with OKC were treated at our institute by peripheral ostectomy, enucleation followed by open packing. This conservative treatment protocol was selected because of relatively young age of the patients and relatively large size of the lesions. All the cases were monitored at regular predetermined intervals using clinical evaluation and panoramic radiographs. There was no evidence of recurrence during follow-up. The conservative treatment protocol for OKC, based on enucleation followed by open packing would be a possible choice in view of the simplicity of surgical procedure and low morbidity. This treatment modality has a low recurrence rate and may be particularly useful in young patients and patients with advanced systemic disease not amenable to major surgical intervention.

Topical 5-Fluorouracil is a Novel Targeted Therapy for the Keratocystic Odontogenic Tumor

PURPOSE

The antimetabolite drug, 5-fluorouracil (5-FU), is used in the treatment of various cancers, including basal cell carcinomas (BCCs). The authors hypothesized that keratocystic odontogenic tumors (KOTs) would respond to 5-FU treatment because of their similarities to BCCs in molecular etiopathogenesis.

MATERIALS AND METHODS

An ambispective cohort study of the treatment efficacy of topical 5-FU on KOTs was conducted. Independent variables included the topical application of 5% 5-FU or modified Carnoy's solution (MC) after enucleation and peripheral ostectomy at the University of Toronto from 2006 through 2014. Outcome variables included time to recurrence and peripheral nerve injury. KOT specimens in these patients were immunostained with p53, Ki-67, thymidylate synthetase (TS), thymidylate phosphorylase (TP), and dihydropyrimidine dehydrogenase (DPD) antibodies. Semiquantitative staining scores were calculated for all immunohistochemistry sections examined. Descriptive statistics were computed using Fisher exact test and Kaplan-Meier analysis as appropriate with the P value set at .05.

RESULTS

Thirty-two patients with 32 KOTs were reviewed (41% in women and 59% in men). There were no KOT recurrences in the 5-FU group (n = 11), whereas there were 4 recurrences in the MC group (n = 21; P = .190). There was a significantly lower incidence of inferior alveolar nerve paresthesia with 5-FU treatment (P = .039). Immunohistochemical staining showed upregulation of TP (P < .0001) and DPD (P < .0001) and no change in TS (P > .05) in inflamed KOTs.

CONCLUSIONS

5-FU effectively treats KOTs with less postoperative morbidity than conventional treatment with MC. Low TS and upregulated TP expressions in inflamed KOTs suggest increased 5-FU efficacy in inflamed KOTs. Topical 5-FU is a novel therapy for KOTs and provides a targeted molecular approach to treatment.

Keratocystic Odontogenic Tumour with Extraosseal Spread: Evaluation of the Effect Carnoy's Solution

Keratocystic odontogenic tumour is relatively rare benign tumour. It is characterized by its fast aggressive growth and high risk of recurrence. Treatment is always surgical: conservative (enucleation, marsupialization) or aggressive (enucleation followed by application of Carnoy's solution, cryotherapy; peripheral ostectomy or en block resection of the jaw). Authors analysed retrospectively 22 patients who fulfilled inclusion criteria, i.e. had odontogenic keratocystic tumour of mandible, wherein antero-posterior dimension was at least 30 mm, and the tumour penetrated into the surrounding soft tissues. All patients underwent tumour enucleation, in 11 patients Carnoy's solution was given into the bone cavity after enucleation. The recurrence rate in the evaluation at least 36 months after surgery was both patient groups the same: 45.4%.

Primordial Odontogenic Cyst with Induction Phenomenon (Zonal Fibroblastic Hypercellularity) and Dentinoid Material Versus Archegonous Cystic Odontoma: You Choose!

The most recent A.F.I.P. fascicle defines primordial odontogenic cyst (POC) as a distinct, nonkeratinized, odontogenic cyst of "undetermined origin" forming in the place of a developing normal or supernumerary tooth. However, the majority of examples reported in the literature under this term represent odontogenic keratocysts (keratocystic odontogenic tumors). In addition, there are rare reported cases of cystic odontomas. An 18-year-old Caucasian male presented with a unilocular mandibular radiolucent lesion in the place of a congenitally missing molar. Histologically, it featured nonkeratinizing, thin stratified squamous epithelial lining with areas of spongiosis and foci of vacuolization of individual basal cells without significant nuclear palisading. Focally, budding of the basal cell layer was identified. A zone of increased cellularity featuring induction-type fibroblasts was present subepithelially as well as dentinoid deposits with odontogenic epithelial nests. Immunohistochemically, the epithelial lining was negative for calretinin and the induction-like zone negative for S100 protein, smooth muscle actin, and CD34. The case was externally reviewed by five oral pathologists who provided various diagnostic interpretations including primordial cyst, odontogenic cyst not otherwise specified (NOS), cyst with ameloblastic changes, and unicystic ameloblastoma. At that time, a final diagnosis of odontogenic cyst NOS was rendered with a comment that it may represent a true example of POC or a cystic odontoma. The lesion has not recurred within a 13 year follow-up period after initial excision. An unusual cystic lesion is presented that may represent a true example of POC with dentinoid formation or an archegonous cystic odontoma.

Possible recurrence of keratocyst in nevoid basal cell carcinoma syndrome: A review of literature

This review will highlight some current areas of difficulty or controversy in diagnosis and treatment of nevoid basal cell carcinoma syndrome (NBCCS). The odontogenic keratocyst (OKC) has significant growth capacity and recurrence potential and is occasionally indicative of the NBCCS. The objective of this study is to clarify the causes of the recurrence of OKC in NBCCS. A literature search was conducted using Medline, accessed via the National Library of Medicine PubMed interface, searching for articles relating to the cause of recurrence of keratocyst in NBCCS written in English. This study has described the previous and the current outcomes of the treatment of OKC (recurrent cause). A protocol was then agreed to search for the possible causes of keratocyst recurrence in NBCCS. The general treatment of other manifestation of NBCCS has excluded from this study. Studies describing cohort, case series and miscellaneous clinical reports were retrieved and evaluated from 2010 to 2012.

Keratocystic odontogenic tumour (KCOT)--a cyst to a tumour

PURPOSE

The World Health Organization (WHO) has reclassified 'odontogenic keratocyst' (OKC) to 'keratocystic odontogenic tumour' (KCOT) in 2005. Currently, this tumour is classified as a benign neoplasm of odontogenic origin and not as a cyst. This article reviews and discusses history, classification scheme, aetiology and pathogenesis, molecular and genetic basis, incidence, epidemiology and site, clinical features, imaging, histopathology, immunohistochemistry, treatment options, prognosis, recurrence and malignant transformation of KCOT, with emphasis on understanding the basis of reclassification as 'keratocystic odontogenic tumour'.

METHODS

A systematic search and review of the literature was carried out in the online database of the United States National Library of Medicine to identify eligible titles for the study.

RESULTS

Current evidence suggests that the scientific community still continues to use the term 'odontogenic keratocyst' more favourably than 'keratocystic odontogenic tumour'.

CONCLUSION

The online database search indicates that the scientific community still continues to use the term 'odontogenic keratocyst' more favourably than 'keratocystic odontogenic tumour'. At this juncture, where the terminology has changed from a cyst to a tumour, a thorough review of literature on KCOT is presented.

Two-stage treatment protocol of keratocystic odontogenic tumour in young patients with Gorlin-Goltz syndrome: marsupialization and later enucleation with peripheral ostectomy. A 5-year-follow-up experience

OBJECTIVE

Keratocystic odontogenic tumour (KCOT) is a benign uni- or multicystic intraosseous odontogenic tumour with potential for local destruction and tendency for multiplicity, especially when associated with Gorlin-Goltz syndrome. We suggest a conservative surgical treatment based on marsupialization and later enucleation with peripheral ostectomy in order to preserve jaw's integrity in young patients.

METHODS

Three young patients affected of nevoid basal cell carcinoma syndrome (NBCCS or Gorlin-Goltz syndrome) presented large and multiple KCOTs, which have been treated following a two-stage surgical strategy. Initially marsupialization was performed and after a mean period of 10 months, contextually to evident reduction in radiological size image, enucleation with peripheral ostectomy was carried out.

RESULTS

All the patients showed high collaboration in daily self-irrigation of the stomia with chlorhexidine 0.2% during the period of marsupialization. Definitive surgical intervention led to complete healing and no signs of recurrence have been observed during a 5-year-follow-up.

CONCLUSIONS

The main advantage of this modality is the preservation of important anatomical structures involved in the lesion and jaw's continuity. Therefore in a selected group of cooperative patients, especially those affected of Gorlin-Goltz syndrome, the surgical protocol exposed allows for a less invasive approach with excellent results avoiding extensive disfiguring procedures.

Conservative Treatment Protocol for Keratocystic Odontogenic Tumour: a Follow-up Study of 3 Cases

Background

The keratocystic odontogenic tumour is classified as a developmental cyst derived from the enamel organ or from the dental lamina. The treatment of keratocystic odontogenic tumour of the jaw remains controversial. The aim of this study was to report the outcome of our conservative treatment protocol for keratocystic odontogenic tumour.

Methods

Three patients with different complaints referred to Oral and Maxillofacial Surgery Clinic, Faculty of Dentistry, Selçuk University. Initial biopsy was carried out in all patients and keratocystic odontogenic tumours was diagnosed subsequent to histopathological examination. The patients with keratocystic odontogenic tumours were treated by enucleation followed by open packing. This conservative treatment protocol was selected because of existing young aged patients. The average follow-up duration of the cases was 2 years.

Results

Out of 3 cases, 2 lesions were present in mandible and 1 lesion in maxilla. There was no evidence of recurrence during follow-up. All the cases were monitored continuously with panoramic radiographs, computed tomography and clinical evaluations.

Conclusions

This conservative treatment protocol for keratocystic odontogenic tumours, based on enucleation followed by open packing would be a possible choice with a view of offering low recurrence rate and low morbidity rate particularly in young patients.

Follicular cyst of the jaw developing into a keratocyst in a patient with unrecognized Gorlin-Goltz syndrome

Gorlin-Goltz (GG) syndrome is an inherited autosomal dominant condition. Its diagnosis may be clinically confirmed by checking either major or minor signs that define the diagnostic criteria. It may occur that, although GG syndrome is a well-known condition, only the specific symptom could be observed by different specialists. Therefore, the patient cannot be placed into an always complex clinical panel. We introduce an example in this report. Throughout a 20-year clinical history characterized by the lack of proper diagnosis and missed follow-up operations, a patient with GG syndrome underwent partial amputation of the jaw after severe complications. A 52-year-old man required an implant-prosthetic rehabilitation since becoming edentulous after a partial resection of the jaw due to a keratocyst, which was later reconstructed through a free fibula flap. The observation of a typical phenotype and various symptoms that succeeded for longer than 20 years, with anamnestic evaluation and clinical examination, led us to suspect a complex pathologic condition such as GG syndrome, which was not previously considered, although the patient had undergone several polyspecialistic evaluations. Diagnosis has been eventually confirmed by a genetic study, which was always mandatory. The simultaneous presence of muscular and skeletal malformations, basocellular nevi, and multiple cysts of the jaw can represent signs linking to a condition such as GG syndrome. There are many syndromes involving the head and neck region, and specialists are supposed to be alerted when faced with similar typical expressions associated with a characteristic soma so as to avoid delays in diagnosing the syndrome.

Endoscopically assisted enucleation and curettage of large mandibular odontogenic keratocyst

This article reports a case of a mandibular multilocular keratocyst treated with endoscopically assisted enucleation and curettage. An ectopic third molar displaced in the coronoid process area was also removed.Odontogenic keratocysts (OKCs) are known for their propensity to recur. The incomplete removal of the cyst is one of the mechanisms for which it is thought that the keratocyst recurs. The endoscopic assistance allowed us to explore accurately the operative field and the areas of difficult access, improving the complete removal of the cystic lesion. Moreover, it allowed us to monitor closely the separation of the cyst lining from the inferior alveolar nerve and limit the extension of the surgical approach. At 3-year follow-up no evidence of recurrence was evidenced by radiological and clinical controls.

Odontogenic Keratocyst: To Decompress or Not to Decompress? A Comparative Study of Decompression and Enucleation Versus Resection/Peripheral Ostectomy

PURPOSE

We discuss the outcome of 2 well-established and widely accepted methods used for the treatment of odontogenic keratocyst (OKC), enucleation with peripheral ostectomy or resection and decompression followed by enucleation and peripheral ostectomy.

PATIENTS AND METHODS

A retrospective chart review of all cases of OKC treated in the University of Maryland's Department of Oral and Maxillofacial Surgery between 1994 and 2004 was undertaken. A total of 31 patients with OKCs was identified. Three of these patients diagnosed with basal cell nevus syndrome and multiple OKCs and 6 patients who did not have adequate follow-up were excluded from this study; thus, 22 patients were evaluated. Of these 22 patients, 11 were treated with resection or enucleation with peripheral ostectomy (group I) and 11 were treated with decompression followed by enucleation when indicated (group II).

RESULTS

A total of 22 patients with biopsy-proven OKC ranging in age from 18 to 90 years were separated into 2 treatment arms. Group I comprised 6 females and 5 males, age 18 to 71 years, with 6 OKCs located in the mandible and 5 in the maxilla. Group II comprised 6 females and 5 males, age 24 to 90 years, with 10 OKCs in the mandible and 1 in the maxilla. The choice of treatment approach was based on the size of the cyst, recurrence status, and radiographic evidence of cortical perforation. The last follow-up revealed no recurrences in group I and 2 recurrences in group II. Both patients with recurrence in group II had undergone enucleation of the same lesion in the past, and both cysts recurred within 2 years after initial treatment.

CONCLUSIONS

Our study results concur with the literature regarding recurrence rates of OKC. The aggressive nature of some OKCs necessitates equally aggressive treatment, whereas long-term follow up even for nonsyndromic patients with single lesions is of paramount importance. Age of the patient and the site and histological characteristics of the treated lesions were not significantly associated with the incidence of recurrence.

Expression of basement membrane components in odontogenic cysts

OBJECTIVE

To compare the expression of basement membrane components (BMCs), including laminins 1 and 5, collagen type IV, and fibronectin in odontogenic keratocysts (OKCs) with dentigerous cysts (DCs) and radicular cysts (RCs).

MATERIALS AND METHODS

Basement membrane components were analysed in 20 OKCs, 20 DCs and 20 RCs using an immunohistochemical technique.

RESULTS

Odontogenic keratocysts, DCs and RCs showed positive reaction to all BMCs studied, with different distributions and intensity. OKCs showed continuous linear deposits for laminins 1 and 5 but two staining patterns (continuous and discontinuous) for collagen type IV and fibronectin. DCs exhibited continuous linear deposits for laminins 1 and 5 and collagen type IV but a discontinuous linear deposit for fibronectin. RCs displayed similar results to DCs for laminin 1, collagen type IV and fibronectin. Laminin 5 in RCs had two staining patterns. Constant results in all cysts were strong intensity for laminin 1 and moderate intensity for laminin 5.

CONCLUSIONS

Substantial differences in the expression of BMCs among studied cysts were not observed, suggesting that the separation of the epithelial lining in OKCs is not associated with the existence of these proteins.

A review of odontogenic keratocysts and the behavior of recurrences

OBJECTIVE

The purpose of this study is to report experiences of odontogenic keratocysts (OKCs) and analyze information regarding recurrences to better understand the nature of recurrences.

STUDY DESIGN

Fifty-one cases of OKC treated at the Faculty of Dentistry, Chulalongkorn University, from 1988 to 2003 were studied retrospectively. Clinicoradiographic features, histologic features, and methods of treatment were reviewed. Recurrences were analyzed and compared with respect to sites of involvement, relationship to the remaining teeth, and methods of treatment.

RESULTS

OKCs occurred predominantly in the 11- to 40-year-old age group. The body-angle-ramus area of mandible was the most common site of occurrence. Radiographically, the unilocular to multilocular radiolucency ratio was 2.5:1. Multilocular lesions occurred more frequently in the mandible (P < .05). Most of the lesions were diagnosed histologically as parakeratinized OKC (93.7%). The patients were followed from 1-14.6 years. However, 20 patients were lost to follow-up after a short period of time, and recurrences were found in 7 out of 31 cases (22.6%). The recurrent tumors occurred more frequently in patients who had an OKC associated with the remaining teeth and were treated by enucleation or enucleation with adjuvant therapy.

CONCLUSIONS

According to a high recurrent rate of OKCs treated by enucleation, clinicians should give more attention to the dentate area if the enucleation is chosen as the treatment of choice.

The aggressive nature of the odontogenic keratocyst: is it a benign cystic neoplasm? Part 1. Clinical and early experimental evidence of aggressive behaviour

In this, the first of three articles on the aggressive nature of the odontogenic keratocyst (OKC), there is a review of clinical and histological observations which indicated that this was an aggressive lesion with a predilection for recurrence unlike the majority of other jaw cysts. This led to the tentative suggestion that the OKC might be a benign neoplasm. Subsequently there were early laboratory investigations that compared proliferation rates of the OKC epithelium with other jaw cysts, comparative enzyme histochemistry to assess aspects of its metabolism and markers that would enable accurate presurgical diagnosis of this cyst. Comparative studies were also pursued on the walls of the OKC and other jaw cysts to identify factors that might influence the capacity of the OKC to resorb the bone surrounding it. The clinical and laboratory studies reviewed in this section provided cogent presumptive evidence of the distinctively aggressive nature of the OKC that led numbers of investigators to pursue immunocytochemical and genetic studies on this cyst. Parts 2 and 3 of this series review this work.

Odontogenic keratocyst: Review of 256 cases for recurrence and clinicopathologic parameters

Odontogenic keratocyst (OKC) is of particular interest because of its high recurrence rate and aggressive behavior. Two hundred fifty-six cases of OKC were reviewed for the age of the patient at diagnosis, sex of the patient, OKC location, and radiographic findings, and 132 patients with OKC were observed to estimate recurrence, which was analyzed for age, sex, location, and several histopathologic findings. OKCs occurred more frequently in men (58.6%) than in women (41.4%), and they occurred in patients within a wide age range, most commonly in patients in the third decade of life (28.9%), followed by those in the second decade (25.0%); the mean age of patients with OKC was 30.8 years. One hundred ninety-six of the 256 cases (76.5%) occurred in the mandible, and the other 60 cases (23.5%) occurred in the maxilla. The mandibular molar and the premolar areas (51.2%) were the most common sites, and the most frequent clinical manifestations at first admission were swelling, pain, or both (82.4% of total cases). Radiographic impressions included dentigerous cyst (27.3%), OKC (25.4%), primordial cyst (14.8%), ameloblastoma (11.7%), residual cyst (9.8%), and radicular cyst (3.1%). The frequency of recurrence at the follow-up examination was 58.3%. There was no significant difference in the recurrence rate on the basis of the sex of the patient. However, OKCs had a significantly higher recurrence rate in patients in the fifth decade of life than in patients in the other age groups (P = .005).Recurrence rates were significantly dependent on the sites of involvement, and OKCs in the mandibular molar region had significantly higher recurrence rates than those in other sites (P = .001). The histopathologic presence of one or more daughter cysts was significantly related to recurrence (P = .03).

Long-term follow-up on keratocysts treated according to a defined protocol

A prospective study was conducted on 82 odontogenic keratocysts (OKCs) diagnosed in 80 patients over a 25 year period. The clinical and radiographic data were correlated, which resulted in an accurate picture of the clinical presentation, relationship with teeth and incidence of lingual perforations in mandibular OKCs. In 40% of the cysts no suspicion had arisen before surgery, in 60% the diagnosis was secured before surgery. This last group of patients was treated according to a defined protocol, with the exception of the maxillary OKCs, which entailed excision of the attached, overlying mucosa and enucleation of the cyst after which the defect was treated with Carnoy's solution. The other patients underwent just enucleation of the cysts. For the first 5 years the patients were seen every year, thereafter every 2 years if possible. Recurrences (9/82) were mainly found in the patients in which the cyst had just been enucleated. Only three cysts recurred in the group treated according to the above mentioned protocol. Most recurrences presented within 5 years, but late recurrences did occur even after 25 years. The aetiology and pathogenesis of OKCs is briefly discussed in the light of the present findings. It is concluded that the suggested treatment protocol and follow-up schedule provides a safe means to manage a lesion that is known to recur and may even give rise to life threatening situations.

Treatment of mandibular odontogenic keratocysts

OBJECTIVE

The purpose of this study was to report our experience with surgical treatment of 31 mandibular odontogenic keratocysts, with special reference to their recurrence, and to review the literature on this subject.

STUDY DESIGN

A retrospective analysis was conducted of all odontogenic cysts treated in the Department of Oral Surgery and Oral Medicine at Jordan University of Science and Technology between 1989 and 1995. Of a total of 227 odontogenic cysts, 31 odontogenic keratocysts were histopathologically diagnosed preoperatively. They were surgically treated through an intraoral approach by resection without continuity defects. The lower border of the mandible and/or the posterior border of the ramus was left intact. In cases where teeth were in continuity with the lesion, they were extracted. In cases where cortical perforation occurred, any associated overlying mucoperiosteum was excised. All patients were reviewed annually for a follow-up period of 2 to 8 years.

RESULTS

All odontogenic keratocysts were found in the mandible. Of these, 23 were in the ramus and angular region (74.2%) and 8 were located in the body of the mandible. No recurrences of the operated odontogenic keratocysts were observed during the follow-up period.

CONCLUSION

Our findings indicate that removal of odontogenic keratocysts by resection without continuity defects is a satisfactory method of treatment.

In situ determination of different dehydrogenase activity profiles in the linings of odontogenic keratocysts and radicular cysts

The levels of succinate, lactate, glutamate, glycerophosphate and glucose-6-phosphate dehydrogenases within the linings of keratinizing and non-keratinizing odontogenic cysts were investigated using static end-point and continuously monitored Nitroblue Tetrazolium-based histochemical methods. The use of TV image analysis for quantification of formazan final reaction products was validated by demonstrating significant relationships between the integrated absorbance at 585 nm and the amount of formazan in, and thickness of, gelatin films containing reduced tetrazolium salt (r = 1.0, p < 0.001). Absorbance readings of stained sections gave mean coefficients of variation of 1.8 +/- 0.9% between day of measurement, and of 5.65 +/- 1.32% between serial sections. End-point assays indicated that the linings of odontogenic keratocysts contained higher levels of glucose-6-phosphate dehydrogenases (p < 0.0002) and lower levels of lactate dehydrogenase (p < 0.002) than those of radicular cysts. Succinate, glutamate and glycerophosphate dehydrogenase activities were similar in both cyst types. Results from continuously monitored assays, performed for glucose-6-phosphate and succinate dehydrogenases, demonstrated linear reaction rates over the first 2.75 min of reaction. The calculated enzyme activities from continuous assays were between 1.49 and 3.49 times higher than those determined from end-point assays and confirmed that levels of glucose-6-phosphate dehydrogenase were significantly higher in the linings of odontogenic keratocysts than those of radicular cysts (p < 0.004). By contrast, succinate dehydrogenase activity was significantly higher in radicular cyst linings (p < 0.03). These results highlight the benefits of an approach to in situ determination of enzyme activity using image analysis and continuous monitoring methodologies. Overall, the high level of glucose-6-phosphate dehydrogenase found in keratocyst linings is consistent with their clinical behaviour and higher level of proliferation and synthetic activity whereas the level of lactate dehydrogenase in radicular cysts probably reflects the presence of local tissue damage within these inflammatory lesions.

Peripheral odontogenic keratocyst

The gingival cyst of the adult exhibits an epithelial lining that is essentially the same as the lateral periodontal cyst. Although the gingival cyst of the adult exhibits some morphologic variability, its lining is generally considered to be nonkeratinized. Nonetheless, rare cases of gingival cyst of the adult that exhibit a keratinized epithelial lining have been reported in the literature. There is now a growing tendency to consider this variant as a separate entity. This article describes six cases of gingival cysts that exhibit the histologic features of the odontogenic keratocyst. Evidence from this series suggests that the biologic behavior of this subset of gingival cysts is different from that of the generic gingival cyst of the adult and that the term peripheral odontogenic keratocyst more accurately describes this entity.

Penetration of the skull base by dissecting keratocyst

The extensive destructive potential of the keratocyst has been well recognized but penetration of the keratocyst into the skull base is rare. 3 cases showing such aggressive behavior and rare location were seen and treated; 2 are reported in this paper. Both cases illustrate the importance of early radical treatment once the aggressive nature of keratocyst is recognized.

Recurrent odontogenic keratocyst within the temporalis muscle

Recurrence following treatment of odontogenic keratocysts is not infrequent. However, recurrence within soft tissues is rarely reported. A case of an odontogenic keratocyst recurring within the temporalis muscle is described with a brief review of the literature concerning cyst recurrence.

Treatment of a large odontogenic keratocyst using the Brosch procedure

The modified Brosch procedure has been described. It represents a reasonable alternative to resection or marsupialization when treating large OKC that occupy the molar, angle, and ramus regions of the mandible. Extraction of teeth affected by the lesion as well as generous removal of partially eroded bone and overlying soft tissues may contribute to lower recurrence rates. Cryosurgical or mechanical treatment of the bony cavity, which is well visualized using this technique, may also lead to improved long-term results. Treatment must be followed by continued, careful observation of the patient.

Recurrence of an odontogenic keratocyst in a bone graft. Report of a case

The recurrence of an odontogenic keratocyst in a bone graft after partial mandibulectomy and reconstruction is presented. The possible reasons for recurrence are discussed, and methods of treatment reviewed.

The primordial cyst (odontogenic keratocyst): its tumour-like characteristics and behaviour

The clinical behaviour of primordial cysts frequently mimics that of benign tumours. They are characterised by aggressive growth and a tendency to recur following surgical treatment. Displacement of teeth, resorption of the roots of teeth, 'seeding' of the cyst into soft tissue and pathological fracture of the mandible exemplify this behaviour. These features are described and fully illustrated by examples from a series of 60 cases. The results of various surgical procedures are evaluated.

Development of a keratocyst in the facial soft tissues

The clinical signs, diagnosis, and therapy of a keratocyst of the soft tissues in a 27-year-old man are described. Part of the keratocyst lining probably grew through the bony window after extraoral biopsy or was implanted in the soft tissue during the procedure, accounting for the location of the lesion.

Odontogenic keratocyst of the maxilla: a case report

Remnants of odontogenic epithelium persist in oral tissues after odontogenesis is complete, and from these remnants a variety of tumours and cysts can arise. Squamous metaplasia can occur in this epithelium which in turn may produce keratin. Although keratin production is a feature of many odontogenic cysts, a specific entity, the odontogenic keratocyst has been defined. The term was first introduced by Philipsen in 1956 and has been used synonymously with that of the primordial cyst. Its capacity for aggressive growth and recurrence even after many years makes it of special interest. In this case report these behavioural characteristics are well demonstrated. The long natural history of the condition in this case and its site and size involved oral, ophthalmic and ultimately otolaryngologic surgeons.

Odontogenic keratocysts: review of the literature and report of sixteen cases

Sixteen cases of odontogenic keratocyst are reported. Two of the patients had basal cell nevus syndrome. The provisional diagnosis in most of the 16 cases was other than odontogenic keratocyst, and the presenting symptoms were usually swelling, pain, and sinus tract formation. The treatment varied from simple enucleation to marsupialization, homogenous bone grafting, and iliac bone grafting. There was a 25% recurrence rate, mostly associated with treatment by enucleation, cysts that were parakeratinized or difficulty in removing the lesion.

The management of keratocysts

The clinical and histological data of 106 keratocysts from the files of the Department of Oral and Maxillofacial Surgery in Nijmegen and Arnhem, The Netherlands, formed the basis of this study. There was a wide age range with a male predominance and with the mandibular third molar area and ramus being the most common sites involved. Special attention has been drawn to the various ways in which recurrent keratocysts may develop. In the present study the recurrence rate of two groups of patients, treated according to two different concepts in the surgical management of keratocysts, are compared. As a result of a 21-year follow-up on 92 keratocysts a rational approach to the surgical treatment to eliminate a high recurrence rate is suggested.

The pathology of head and neck tumors: cysts of the jaws, part 12

The jaws are unique bones of the skeleton because of their intimate involvement with tooth and facial development. Abnormal sequelae of these developmental processes may give rise to cystic lesions later in life. This paper reviews the pathogenesis, clinical features, and behavior of these odontogenic and nonodontogenic cysts. Justification is found for the exclusion of the globulomaxillary, midmandibular, and midpalatine cysts from a current classification. Emphasis is placed on the importance and controversy surrounding the odontogenic keratocyst.

What is Gorlin's syndrome? The diagnosis and management of the basal cell naevus syndrome, based on a study of thirty-seven patients

A series of 37 patients with Gorlin's syndrome is described; 23 had the typical naevi, 19 had jaw cysts and only 10 had both. A wide range of associated deformities was noted. The need for early identification of patients at risk is stressed; follow-up is essential for 2 reasons: The naevi although indistinguishable histologically from basal cell carcinomas only rarely require radical removal. The jaw cysts are locally invasive and should be radically removed when small. In 8 patients examined there was a low level of alpha-globulins in the plasma. Spontaneous involution of the naevi may occur in un-irradiated skin.