Frequency and Demographic Analysis of Odontogenic Tumors in Three Tertiary Institutions: An 11-Year Retrospective Study

Odontogenic tumors (OTs) are distinct conditions that develop in the jawbones, exhibiting diverse histopathological features and variable clinical behaviors. Unfortunately, the literature on this subject in Saudi Arabia remains sparse, indicating a pressing need for more comprehensive data concerning the frequency, demographics, treatment modalities, and outcomes of OTs.

OBJECTIVES

The study aims to evaluate the frequency, demographic features, treatment, and outcomes of OTs across three tertiary medical centers.

METHODS AND MATERIAL

OT cases were identified in King Abdulaziz Medical City (KAMC), King Fahad Medical City (KFMC), and Prince Sultan Military Medical City (PSMMC) from January 2010 to December 2021.

RESULTS

Ninety-two OT cases were identified from the anatomical pathology laboratories of three tertiary hospitals. KFMC contributed the highest number of cases (43.5%), followed by KAMC (30.4%) and PSMMC (26.1%). The median age of OT patients was 29 years (range: 5-83), with males representing more than half of the patients (56.5%). The mandible was the most frequent site of OT occurrence (72.5%), with ameloblastoma being the predominant OT (63.0%), followed by odontoma (19.5%). Among the treatment modalities, bone resection was employed the most (51.0%), followed by enucleation (25.6%). Notably, 11.5% of OT cases with available follow-up data exhibited recurrence, with ameloblastoma accounting for eight recurrent cases.

CONCLUSIONS

Although OTs are relatively common in the jaws, they are rare in anatomical pathology laboratories and the general population. This study contributes valuable insights into the epidemiology characteristics, treatment trends, and recurrence rates of OTs in Saudi Arabia.

Retrospective analysis of odontogenic myxoma and odontogenic myxofibroma in the oral and maxillofacial region: a fibrous tissue-related differentiation

The clinical differences between odontogenic myxoma (OM) and odontogenic myxofibroma (OMF), and the clinical significance of their classifications, remain unclear. This study reviewed the clinicopathological characteristics of patients with OM or OMF and evaluated the fibrous component of the specimens. Medical records of 21 patients with OM or OMF who underwent tumour resection were reviewed. The percentage of fibrous tissue on the representative sections was evaluated using haematoxylin and eosin- and Masson's trichrome-stained specimens. Histopathological diagnoses included 11 OMs and 10 OMFs with no tumour recurrence except for two cases in which the dredging method was applied. More cortical bone perforation was observed in OM than in OMF cases, without significant differences. Location-locularity and apparent diffusion coefficient value (ADC)-cortical bone perforation were significantly correlated in all OM and OMF cases. The percentage of fibrous tissue in specimens showed bimodal distribution bordered by 45%. There was a significant association between diagnosis based on 45% fibrous tissue criterion and the final pathological diagnosis. Our study showed a tendency for cortical bone perforation in OM compared to OMF and correlation between ADC and cortical bone perforation. According to the histopathological analyses, the fibrous component of each case was bimodal with 45%, which may be a criterion to distinguish between OM and OMF. Accumulating knowledge, such as significant differences in prognosis, may allow for minimal surgical treatment options based on the diagnosis according to this novel histopathological criterion.

Angiogenesis in patient-derived xenografts of odontogenic myxoma

Previously, by employing 3D organotypic tissue culture and patient-derived xenograft (PDX) model, oral myxoma response to a MAPK/MEK inhibitor was observed. Gross examination of the tumour fragments obtained after 55 days of PDX grafting revealed increased capsule vascularization. Microscopic analyses showed blood capillaries intermixed with myxoma cells, but the origin of these capillaries, from mice or humans, was not established. This study aimed to investigate whether the endothelial cells observed in the myxoma PDX model are derived from the mouse or from the primary human tumour. Immunohistochemistry was performed on five tumour fragments from the PDX of myxoma after 55 days of implantation in mice. Immunopositivity for antibodies against human (HLA-ABC) and mouse (H2 Db/H2-D1) major histocompatibility complex class I (MHCI) was assessed in the endothelial cells. The endothelial cells in the PDX fragments revealed a membrane staining for the human MHCI protein in the PDX tumour and adjacent connective tissue capsule, indicating that capillaries were derived from the human tumour fragment. Considering the probable human origin of the endothelial cells from capillary blood vessels in the myxoma PDX, we conclude that this PDX model is an interesting model to study myxoma angiogenesis.

Odontogenic Myxoma: Systematic review and bias analysis

BACKGROUND

Odontogenic myxoma (OM) is a rare neoplasm, which originates from odontogenic ectomesenchyme. There is no study in the literature that analyses the best standards for OM diagnosis and how the treatment modalities may influence the recurrence rates.

OBJECTIVE

To evaluate the best standards for odontogenic myxoma (OM) diagnosis and treatment, and how these may influence the recurrence rates.

STUDY DESIGN

Two independent researchers performed a systematic review in many databases. Fifty-two eligible studies were included for qualitative analysis. Bias analysis was conducted according to Oxford Centre for Evidence-Based Medicine.

RESULTS

A total of 1363 OM cases were reported on, and female gender with average age of 27 years is the most common patient profile. Conventional microscopic findings were observed in 93.43% of the reported cases. In 57.49% of the cases, multilocular radiographic appearance was present, followed by unilocular appearance (32.87%). Posterior mandible was the site with the major prevalence, while surgical resection was the most common treatment modality, followed by enucleation. Recurrence rates for both treatment modalities were approximately close (13.04% and 25.0%, respectively).

CONCLUSION

The correct diagnosis of OM relies on the association of clinical, radiographic and microscopic findings. About imaging examinations, panoramic radiography and computed tomography are sufficient for the evaluation of OM. Recurrence rates were closely among the two most used surgery treatments. So according to some clinical-radiological aspects, conservative surgery may be preferred than aggressive surgery modalities.

Recurrence rate of odontogenic myxoma after different treatments: a systematic review

Our aim was to establish the recurrence rate of odontogenic myxoma after different treatments. Our search covered papers from 1972-2017 from different sources. The papers were evaluated and critically appraised by two independent investigators. The recurrence rate and 95% CI were calculated in relation to each specific treatment, and the chi squared test was calculated to find out if there was any significant difference in the recurrence rate between conservative treatment and resection. The overall recurrence rate was 5 of 39 patients (13%) during a mean follow up period of 10 years. With conservative treatment the recurrence rate was 4/22 (19%) (mean follow up 11 years) and after resection it was 1/17 (6%) (mean follow up nine years). Maxillary lesions were more likely to recur than mandibular ones. Quality of life variables such as disfigurement and neural deficit were more common after resection than with conservative treatment. The frequency of recurrence was relatively low over 10 years' follow up, irrespective of whether resection or a more conservative approach was used, despite being slightly lower (as might be expected) after resection. Conservative treatment should be considered first to avoid resection-associated morbidity and the effect on the quality of life. Maxillary lesions have more room to spread before they are clinically evident, making them difficult to treat optimally and contributing to the recurrence rate.

Odontogenic myxoma in an 8-year-old girl: A case report with review of literature

Aggressive enlargements of maxilla in pediatric patients are uncommon and present with diagnostic and therapeutic dilemma. The decision on therapeutic modality is based on an early and accurate diagnosis, minimizing disease-associated morbidity which is of utmost importance considering the young age and thereby resulting in better prognosis. Odontogenic myxoma is a locally aggressive lesion which is primarily seen in relation to odontogenic apparatus in mandibular posterior region in association with an impacted tooth. This presentation describes a unique case of odontogenic myxoma of anterior maxilla in an 8-year-old girl with emphasis on its diagnosis and treatment planning.

Bringing benign ectomesenchymal odontogenic tumours to the lab: An in vitro study using an organotypic culture model

BACKGROUND

Benign neoplasms exhibit most of the cellular phenomena considered hallmarks of cancer, except the capacity to metastasize. Thus, the elucidation of the mechanisms associated with the progression of benign neoplasms may complement and clarify the mechanisms involved in carcinogenesis. Benign odontogenic tumours often result in facial deformities and morbidities, and have complex pathogenesis, mainly due to the diversity of interactions between the odontogenic epithelium and the ectomesenchyme. Primary cell culture of such tumours is not only difficult to be established and maintained, but also tumour cells lose characteristic cellular morphology. Considering gene expression, growth, migration, proliferation and cellular morphology are controlled by cell-cell interactions and cell-extracellular matrix interactions, cell culture in 3D substrates has gained space as a way to overcome some of the limitations of traditional monolayer cell culture systems.

METHODS

In this study, fragments obtained from mesenchymal odontogenic tumours were cultured in type I collagen scaffolds. Invasion tests were performed in these models, as well as phenotypic characterization of the cultured tumours.

RESULTS

The results obtained for the odontogenic myxoma and the cemento-ossifying fibroma demonstrate a good reproduction of the growth pattern of these tumours under ex vivo conditions. Microscopic evaluation showed maintenance of cell viability in the explants for more than 30 days, without the presence of necrosis.

CONCLUSION

This is the first study involving long-term 3D primary cultures of benign odontogenic tumours, which is expected to support complex approaches to cell and molecular biology, and to serve as an experimental model for testing molecular therapies.

Odontogenic myxoma: An updated analysis of 1,692 cases reported in the literature

The aim of the present study was to integrate the available data published on odontogenic myxoma (OM) into a comprehensive analysis of its clinical/radiological features. Electronic search undertaken in January/2018, looking for publications reporting cases of OM. A total of 377 publications were included. We identified 1,692 lesions, and 695 were used for the analysis of recurrence. There is a predominance of OMs in females and in mandibles. OMs usually present with bone expansion, asymptomatic cortical perforation, and a multilocular appearance. Lesion location (maxilla/mandible), bone expansion, cortical bone perforation, locular radiological appearance, tooth resorption, odontogenic epithelial rests, or angular septa are not associated with recurrence. While curettage (31.3%) showed the highest recurrence rate, marginal resection (1.3%) and segmental resection (3.1%) showed the lowest values. Enucleation + peripheral osteotomy (6.7%) showed better results than enucleation (13.1%) or enucleation + curettage (12.7%). In comparison with unilocular lesions, multilocular ones were significantly more prevalent in mandibles, more often presented expansion and cortical bone perforation, had larger mean size, and were more often treated by segmental resection. Conservative surgical procedures are associated with higher probability of recurrence of OM. Taking into consideration the recurrence rate and morbidity associated with different surgical treatments, tumor enucleation followed by peripheral osteotomy should be considered as the first therapeutic choice.

Size distribution and clinicoradiological signs of aggressiveness in odontogenic myxoma-three-dimensional analysis and systematic review

OBJECTIVES

Therapeutic assessment of odontogenic myxoma (OM) is poorly standardized. Unidimensional size criteria have shown to be unreliable in therapeutic decision-making. We evaluate the size distribution of OM and scan for associated clinicoradiological signs of aggressiveness. Additionally, we evaluate three-dimensional size delineation of OM aiming to improve future therapeutic assessment of this destructive neoplasm.

METHODS

Primarily, we reviewed the database "PubMed" for data concerning the size of OMs as radiologically determined. Afterwards, the impact of age, sex, locularity and location on the size was investigated by χ² test, Student's t-test and regression analysis. Furthermore, we statistically evaluated the impact of size on the occurrence of clinicoradiological signs of aggressiveness. Secondly, we approximated the volume of five unpublished cases of OM by semi-automatic image segmentation of cone-beam CT images.

RESULTS

Multilocular OMs were significantly larger than unilocular ones (p < 0.002). Age (0.042) and multilocularity (<0.002) significantly impacted size. Size was significantly associated with cortical perforation (0.032) and multilocularity (<0.002), further regression analysis revealed tooth resorption (0.019), cortical perforation (0.005) and multilocularity (<0.002) as significant predictors of size. Employing the volume as a mean of comparison, we found that the biggest OM (38.42 ml; multilocular) was 124 times larger than the smallest (0.31 ml; unilocular). However, using the maximum diameter (cm) as a surrogate for size, the biggest lesion (6.3) was only 5.25 times larger than the smallest (1.2).

CONCLUSIONS

Locularity and volumetric size characterization might help in therapeutic decision-making and could help to improve our understanding of OM.

Characteristic features of the odontogenic myxoma on cone beam computed tomography

OBJECTIVES

To illustrate the characteristic features of odontogenic myxoma (OM) on CBCT.

METHODS

From 52 subjects with histopathologically diagnosed OMs, 18 subjects who underwent a CBCT examination were retrieved between May 2009 and April 2016. Features on CBCT images and clinical records were carefully observed and analyzed.

RESULTS

Characteristic features include: (1) fine and straight septa that were recognized to separate the tumour into triangular, square or rectangular spaces, which appeared as "tennis racket" or "honeycomb" patterns; (2) septa that frequently scattered to the borders of lesions and appeared perpendicular to the margins; (3) tooth displacement and resorption that were seen in most of the OM lesions; (4) OMs that were noted to have a tendency to involve the alveolar process, scallop between the roots and affect the integrity of the alveolar ridge; (5) the cortex of OMs that appeared normally perforated and the edge of the cortex expanded into the soft tissue.

CONCLUSIONS

CBCT is highly effective in demonstrating the comprehensive internal structures of the lesions precisely and providing detailed information for the diagnosis of OM.

Odontogenic myxoma in the paediatric patient: a review of eight cases

Paediatric odontogenic myxoma (OM) is a rare pathological condition in the oral and maxillofacial region. There has been much debate in the literature regarding the preferred method of treatment; however due to the rare nature of this disease, definitive algorithms of management are yet to be determined. A case series of eight paediatric patients with OM is presented. Six of the lesions were in the maxilla and two were mandibular lesions. The patients were aged between 2 and 18 years. Treatment ranged from excision and the application of Carnoy's solution to segmental resection and reconstruction. From this case series it can be seen that even in situations where treatment was limited to excision and the application of Carnoy's solution, no recurrences occurred. As such the present authors favour an initially more conservative approach to the management of these lesions where possible and reserving conventional resective treatment for recurrences, lesions causing pathological fracture, and those in regions that are difficult to access.

Assessment of CD-105 as an Angiogenic Modulator in Odontogenic Myxomas and Dental Follicles

Aim Odontogenic myxoma is a benign intraosseous neoplasm of the jaws, with a locally aggressive behavior and a high recurrence rate. CD-105 is a homodimeric cell membrane glycoprotein and is a component of the TGF-β1 growth factor receptor complex that modulates angiogenesis by regulating the proliferation, differentiation and cellular migration. The aim of this study is to quantify the microvascular density of the odontogenic myxoma based on the expression of CD-105. Materials and Methods The analysis included 18 odontogenic myxoma and 18 dental follicles as controls. A standard immunohistochemical procedure was performed with the CD-105 antibody. Five representative fields (40×) of the odontogenic myxoma and the dental follicles were selected to determine the microvascular density, which was then followed by a descriptive and comparative statistical analysis. Results Dental follicles presented a significantly higher microvascular density compared with odontogenic myxoma (P = .001). The odontogenic myxoma smaller than 3 cm showed a greater microvascular density than those larger than 3 cm in size (P > .05), and the microvascular density was lower in large odontogenic myxomas as compared with the dental follicles (P = .003). Conclusion A weaker expression of CD-105 in odontogenic myxoma might indicate a lower angiogenic activity, suggesting that vascular proliferation has a limited role in the growth mechanisms and in the aggressive behavior of this neoplasm.

Novel Association of Odontogenic Myxoma with Constitutional Chromosomal 1q21 Microduplication: Case Report and Review of the Literature

Odontogenic myxoma (OM) is a rare, benign, and locally aggressive tumor. It tends to occur in the posterior maxilla and mandible and is often associated with root resorption and perforation of cortex. Histopathologically, there is a proliferation of spindle, bipolar, and stellate cells, with bland nuclei within a myxoid to infrequently fibromyxoid extracellular matrix. Long, thin residual bony trabeculae are often seen floating within the spindle cell proliferation because of the infiltrating nature of this tumor, and these trabeculae impart a "soap bubble" or "tennis-racket" radiologic appearance. No syndromic association of OM has been reported. Although similar histopathologic features are shared with cardiac myxoma and soft tissue myxoma, mutations in the GNAS gene have not been identified in OM to date, and only 2 of 17 OMs showed mutations in the PRKAR1A gene. In this report, we describe a case of OM in a patient with constitutional 1q21 microduplication, a locus that harbors genes encoding certain proteins in the cAMP-dependent protein kinase A (PKA) signaling pathway, including G-protein-coupled receptors and 1 phosphodiesterase interacting protein. Review of the literature describes the key clinical features and molecular pathogenesis of 1q21 microduplication, as well as highlighting the role of PKA signaling pathway in the pathogenesis of myxomas in general.

Odontogenic myxoma: a clinicopathological study in a South African population

BACKGROUND

Odontogenic myxoma is a benign, locally aggressive neoplasm of the jaws. Prevalence rates range between 0.5% and 17.7% of odontogenic tumours. There are few reports in the literature on this lesion in African populations, and therefore, this study aimed to report on odontogenic myxoma in a South African population over a 40-year period.

METHODS

The clinical records and orthopantomograms of 29 histopathologically diagnosed odontogenic myxoma were retrospectively analysed. Details of age, gender, ethnic origin and clinical, histological as well as radiological features were recorded.

RESULTS

The ages of patients ranged from 7 to 44 years with a mean of 21.3 years. The male-to-female ratio was 1:2.6 with the majority of patients being of mixed race and Africans. Clinically, 31% complained of pain while 58.6% had a history of swelling. The majority of odongenic myxomas (62.1%) were located in the mandible with the posterior region being most commonly affected. Multilocular lesions (69.2%) were more common and were significantly larger than unilocular lesions (P < 0.05). The outline of these tumours was mostly well-defined (84.6%) with different degrees of cortication. Only one tumour caused tooth resorption, while 20 cases (76.9%) caused tooth displacement. Six tumours expanded into the maxillary sinus, and 14 tumours caused expansion of the mandible.

CONCLUSIONS

Odontogenic myxomas have variable clinical, radiological and histological features. Most of these features in this population were similar to other populations. It is mandatory to use conventional radiographs along with histopathological examination to aid in arriving at an accurate diagnosis.

A rare case report of myxoid fibroma of maxilla

This case report describes about a swelling in maxillary right posterior teeth region. On examination the swelling was solid, pinkish, red, non-ulcerated & non-tender overgrowth at the right maxillary posterior teeth region with no buccal or palatal expansion. Panoramic radiograph revealed a faint radiolucent area with few radiopaque foci and histopathological examination showed myxoid fibroma. Further, correlation of clinical, radiological & histopathological feature; essential to diagnose lesion which lack the characteristic features are also discussed.

Odontogenic myxoma: Report of three cases and retrospective review of literature in Indian population

Purpose:

To review the clinical pattern and treatment modalities meted out to patients of odontogenic myxoma (OM) in Indian population in last 30 years and also to report 3 cases of OM.

Method:

A retrospective review of radiograph and histopathology of three cases of odontogenic myxoma treated between 2005 and 2011 was done. Immunohistochemical analysis was performed to examine the pattern of vimentin and NSE. Also a computerized literature search using Medline and Google scholar was conducted for published articles on OM in Indian population in last 30 years.

Result:

A total of 32 OM cases reviewed from 25 articles retrieved. Out of them 24 myxomas were present in maxilla, only 8 were in mandible and a single case was present in supraglottic region (larynx). Surgical procedure carried out was excision and curettage in 16 patients and resection with safe margin followed by reconstruction 13 patients. All the three reported cases were successfully treated by tumor enucleation and peripheral ostectomy with no recurrence after 3 to 7 years.

Conclusion:

Odontogenic myxoma is a rare odontogenic tumor with inconclusive clinical and radiographic features, hence histopathological examination is mandatory to confirm its diagnosis. Although the immunohistochemical analysis may help in diagnosis but plays no role in guiding treatment planning or predicting the rate of recurrence. Currently we lack data on number of reported OM cases in Indian population as author feels more patients must have been treated then reported.

Odontogenic myxoma of maxilla: A rare presentation in an elderly female

Odontogenic myxomas are rare benign neoplasm of mesenchymal origin, comprising 3-6% of all odontogenic tumors. They are slow growing, non-metastasizing, often asymptomatic with local aggressiveness due to its infiltrative nature and hence high recurrence rate, with a high incidence of occurrence in the mandible. Most frequently occurs in second to third decade of life, seldom occurs beyond these age groups. Hereby, we present a case of odontogenic myxoma occurring in the maxilla in a 65-year-old female managed by partial maxillectomy.

Odontogenic myxoma of maxilla: A review discussion with two case reports

Odontogenic myxoma (OM) is a rare entity of slowly growing benign neoplasm of ectomesenchymal origin, comprising of 3-6% of all odontogenic tumors that histologically presenting spindle-shaped, stellate and round cells within loosely arranged myxomatous tissue stroma. OM originates from the dental papilla, follicle or periodontal ligament with an exclusive location in the tooth-bearing areas of the jaws, association with missing or unerupted teeth. Clinically and radiographically the reported incidence and demographic information of this tumor has wide variability. Most common clinical variant is associated with the impacted tooth and shows local invasion with destruction of adjacent structures and displacement of teeth. Radiographically, common manifestations are multilocular radiolucent areas with well-defined borders and typical soap bubble or tennis racket appearances. This paper presents two rare case reports of OM of maxilla along with review discussion.

A large odontogenic myxoma of the bilateral maxillae: A case report

Odontogenic myxomas (OMs) are benign mesenchymal locally aggressive neoplasms of the jaw bone. Although OMs predominantly involve the mandible, maxillary tumors are usually more aggressive than mandibular tumors. The present study describes the case of a 37-year-old male with a large odontogenic myxoma of the bilateral maxillae, which caused a defect in the right skull base bone. The tumor was successfully removed through radical resection of the hard tissue and local resection around the envelope of the soft tissue. The tumor exhibited no recurrence. However, the current methods for bilateral maxillary reconstruction to restore the maxillary buttress and achieve an optimal aesthetic appearance are complicated due to the lack of suitable conditions for oral rehabilitation with good dentition.

Surgical treatment of odontogenic myxoma and facial deformity in the same procedure

Odontogenic myxoma (OM) is an uncommon benign tumor with aggressive and invasive behavior. Predominant symptoms are usually slow and painless swelling, sometimes resulting in perforation of the cortical borders of the affected bone. In this paper, a case report of a patient with an OM on the right maxillary sinus and a vertical excess of maxilla will be presented. The treatment chosen was tumor resection in association with orthognathic surgery with biomodels assessment for surgical planning. A 3-year follow-up showed disease free and stability of the new position of maxilla. The international literature is evaluated to discuss this case report.

Oncologic profile of maxillary odontogenic myxoma: A rare case

Odontogenic myxoma (OM) is an ectomesenchyme derived neoplasm, almost exclusively found in jaws. This article presents a maxillary OM with a brief review of the molecular and proteomic antecedents of OMs, capturing its histopathogenesis.

The orosomucoid 1 protein (α1 acid glycoprotein) is overexpressed in odontogenic myxoma

BACKGROUND

Odontogenic myxoma (OM) is a benign, but locally invasive, neoplasm occurring in the jaws. However, the molecules implicated in its development are unknown. OM as well as Dental Follicle (DF), an odontogenic tissue surrounding the enamel organ, is derived from ectomesenchymal/mesencyhmal elements. To identify some protein that could participate in the development of this neoplasm, total proteins from OM were separated by two-dimensional electrophoresis and the profiles were compared with those obtained from DF, used as a control.

RESULTS

We identified eight proteins with differential expression; two of them were downregulated and six upregulated in OM. A spot consistently overexpressed in odontogenic myxoma, with a molecular weight of 44-kDa and a pI of 3.5 was identified as the orosomucoid 1 protein. Western blot experiments confirmed the overexpression of this protein in odontogenic myxoma and immunohistochemical assays showed that this protein was mainly located in the cytoplasm of stellate and spindle-shaped cells of this neoplasm.

CONCLUSION

Orosomucoid 1, which belongs to a group of acute-phase proteins, may play a role in the modulation of the immune system and possibly it influences the development of OM.

Odontogenic myxoma with diffuse calcifications: a case report and review of the literature

This is a case report of an unusual odontogenic myxoma with calcifications, one of three reported in the literature. It had a typical radiographic appearance although it presented in an older patient. The presence of osteo-cementum-like calcification raises other differential diagnoses but does not in and of itself mitigate the diagnosis. The patient has not shown recurrence 14 months after resection and 11 months after reconstruction and continues to be closely monitored.

Odontogenic myxoma of the maxilla

Myxomas are mostly seen in the 2(th) and 3(rd) decades. They rarely occur in childhood and maxillofacial region is rarely involved. The recurrence incidence is high. We report this unusual case occurring in a 9-year-old girl in the maxillofacial region and recurrence four months after initial treatment.

MIB-1, Bcl-2 and p53 in odontogenic myxomas of the jaws

Odontogenic myxoma is a rare benign neoplasm occurring in the jaws. Microscopically, it is composed of spindle or stellate-shaped cells arranged in a mucinous matrix. In some cases (20%), odontogenic epithelial islands may be found. The Authors evaluated p53, MIB-1, and Bcl-2 expressed by the epithelial and stromal elements in 12 cases of odontogenic myxoma of the jaws. The cells of the odontogenic epithelium were positive for Bcl-2, p53 and MIB-1. The stromal cell showed a high positivity for MIB-1. Proliferation of both the epithelial and stromal components could be related to the growth of this odontogenic tumour.