Mutations in SH3BP2, the cherubism gene, were not detected in central or peripheral giant cell tumours of the jaw

Giant cell granulomas of the jaw (GCGJ) are non-familial, generally unilateral osteoclast-rich lesions that are histopathologically indistinguishable from cherubism. Cherubism is an autosomal dominant disease that is characterised by bilateral radiolucencies of the jaw, and caused by mutations that occur in SH3BP2 exon 10. The aim of the study was to screen lesional GCGJ tissue for SH3BP2 mutations. Lesional mononuclear stromal or spindle cells were microdissected from paraffin-embedded tissue from GCGJ, and DNA was then extracted and sequenced for SH3BP2 mutations associated with cherubism. No mutations were detected in 26 GCGJ (15 central, 11 peripheral), which indicated that people with GCGJ do not harbour cherubism-related germline SH3BP2 mutations, and that GCGJ do not harbour somatic SH3BP2 mutations. This suggests that cherubism and GCGJ arise on a different genetic background, and therefore detection of SH3BP2 mutations can be a useful means of distinguishing between them.

Keratocystic odontogenic tumour: reclassification of the odontogenic keratocyst from cyst to tumour

The purpose of this paper is to review the features and behaviour of the odontogenic keratocyst (OKC), now officially known as the keratocystic odontogenic tumour (KCOT); to analyze a series of histologically confirmed KCOT cases; and to review and discuss the redesignation of KCOT and the implications for treatment. Redesignation of the OKC as the KCOT by the World Health Organization (WHO) is based on the well-known aggressive behaviour of this lesion, its histology and new information regarding its genetics. Abnormal function of PTCH, a tumour suppressor gene, is noted to be involved in both nevoid basal cell carcinoma syndrome and sporadic KCOTs. Normally, PTCH forms a receptor complex with the oncogene SMO for the SHH ligand. PTCH binding to SMO inhibits growth-signal transduction. SHH binding to PTCH releases inhibition of the signal transduction pathway. If normal functioning of PTCH is lost, the proliferation-stimulating effects of SMO are permitted to predominate. A review of the literature was conducted and results were tabulated to determine whether treatment modality is related to recurrence rate. More aggressive treatment - resection or enucleation supplemented with Carnoy"s solution with or without peripheral ostectomy - results in a lower recurrence rate than enucleation alone or marsupialization. Notably, the recurrence rate after marsupialization followed by enucleation is not significantly higher than that following the so-called aggressive modalities. Our case series consists of 21 patients treated for KCOTs. Results were organized to demonstrate recurrence as it relates to size of lesion and time since treatment and incidence as it relates to patient age and location in the jaws. In our series, the average KCOT surface area measured radiographically was 14 cm². Most lesions were within the 0-15 cm² range and lesions in this range resulted in the greatest number and proportion of recurrences. The recurrence rate of 29% in our case series was consistent with previously established data; all recurrences occurred within 2 years post-intervention. The incidence of primary lesions was highest in the age group 70-79 years; most lesions occurred in the posterior mandible. WHO"s reclassification of the OKC as the KCOT based on behaviour, histology and genetics underscores the aggressive nature of the lesion and should motivate clinicians to manage the disease in a correspondingly aggressive manner. The most effective interventions for the KCOT are either enucleation with Carnoy"s solution, or marsupialization with later cystectomy. Future treatment may involve molecular-based modalities, which may reduce or eliminate the need for aggressive surgical management.

Eosinophilic granuloma of the jaws: an analysis of clinical and radiographic presentation

Eosinophilic granuloma (EG) is the localized and mildest form of histiocytosis-X group of diseases. In this study, 22 patients of pathologically proven EG involving the jaws were retrospectively studied concerning the clinical and radiographic presentation. The clinical and radiographic presentation of the 22 cases was quite varied, and the accuracy of clinical and radiographic diagnosis was low. However, the clinical and radiographic presentation correlated with the lesion site, and accordingly all the jaw lesions could be divided into three types (Alveolar Type, Intraosseous Type, and Mixed Type). Our classification based on the lesion sites reveals the correlation between the clinical and radiographic presentation of EG and the lesion sites, and may be useful in the identification of lesions of EG in the jaws.

Follow-up form for patients undergoing orthognathic surgery

Patients undergoing orthognathic surgery need quantitative follow-up of many parameters. Standardization and recording of data should be done with minimal paper work and time. The patient follow-up form presented enabled the authors' clinic to increase the quality of follow-up. The form consists of more than 20 variables that are routinely evaluated in all patients undergoing orthognathic surgery. It facilitates the cross-evaluation of many variables easily and more accurately. This type of accurate recording would also be beneficial in the event of medico-legal issues. The authors believe this form would be helpful to clinics that have a large number of patients undergoing orthognathic surgery.

In vivo correlation of noncarious cervical lesions and occlusal wear

STATEMENT OF PROBLEM

The etiology of noncarious cervical lesions is not well understood. An understanding of the etiology helps the clinician determine appropriate treatment and management strategies. Purpose This study evaluated the relationship between noncarious cervical lesions and occlusal (or incisal) wear.

MATERIAL AND METHODS

Casts (n = 299) made from dental students were articulated in a semi-adjustable articulator and evaluated. Data included the presence and contour of noncarious cervical lesions (NCLs) and the presence, location, and severity of any occlusal/incisal wear facets. Also included were Angle's classification, occlusal guidance patterns, midline, presence of tori, tooth restoration, reverse articulation (crossbite), open occlusal relationship, and posterior excursive contacts where present. Following a calibration procedure, 2 evaluators made independent observations on the casts. The first evaluator recorded for each tooth in each subject: presence and severity of NCLs, presence and extent of occlusal/proximal restorations, and presence of reverse articulation and open occlusal relationship. Following the first evaluation red rope wax was placed at the cervical margins of each tooth for the purpose of blinding the second evaluator from NCL observations. The second evaluator recorded severity and location of occlusal/incisal wear, presence or absence of posterior excursive contacts, Angle's classification, occlusal guidance pattern, any midline discrepancy, and presence or absence of tori. The Spearman correlation coefficient and chi 2 tests were used to analyze the data (alpha=.05).

RESULTS

There was no relationship between noncarious cervical lesions and occlusal/incisal wear. There was also no correlation between NCLs and other parameters examined.

CONCLUSIONS

Under the conditions of this study, noncarious cervical lesions are not related to occlusal wear.

[The odontogenic keratocyst--odontogenic cyst or benign tumor?]

The odontogenic keratocyst is the third most common cyst of the jaws, after the follicular and radicular cyst. Keratocysts most commonly occur as single lesions in the jaw of otherwise healthy persons. Multiple odontogenic keratocysts are a well-recognized feature of the nevoid basal cell carcinoma syndrome. The mandible, especially the third molar region, the angle of the mandible and the ascending ramus are involved far more frequently than the maxilla. Clinically, the cysts often remain asymptomatic and there are two specific histological entities: the orthokeratinized and the parakeratinized odontogenic keratocyst. Different surgical treatment options like marsupialization, enucleation with curettage or peripheral ostectomy, and osseous resection (marginal or segmental) have been discussed in the literature with variable rates of recurrence. Besides a predilection for recurrence, the keratocysts, in contrast to other odontogenic cysts, show a more aggressive clinical behavior and demonstrate a high mitotic count and higher turnover rate of the epithelium. This led to the tentative suggestion that the keratocyst might be a benign cystic neoplasm rather than simply an odontogenic cyst.

Is primary chronic osteomyelitis a uniform disease? Proposal of a classification based on a retrospective analysis of patients treated in the past 30 years

INTRODUCTION

Primary chronic osteomyelitis of the jaw is a rare, non-suppurative, chronic inflammatory disease of unknown aetiology. To date, classification is confusing due to a non-uniform terminology. The aim of this study was to establish a simple (clinical) classification based on patient data from our clinic.

METHODS

Retrospective analysis revealed 30 cases of which clinical course, radiology, pathology, therapy and outcome were analysed.

RESULTS

Both sexes were equally represented. The mean age at onset of disease was 35 years (range 5-76 years). Onset of disease revealed two peaks of incidence, one in adolescence and one after age 50 years. While clinical symptoms were similar in all cases, an increased intensity of these symptoms was noted in younger individuals as well as in the early stages of the disease. Five adults and one adolescent presented with additional non facial bone, joint and skin manifestations consistent with the diagnosis of SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome, or chronic recurrent multifocal osteomyelitis. Radiology demonstrated sclerosis, osteolysis and periosteal reaction in variable stages in all cases. However, findings were more extensive in younger patients. Histology revealed different stages of chronic inflammation in all cases. Microabscess formation was noted in 11 cases, six of which were children/adolescents. Therapy consisted mainly of surgery, antibiotics and hyperbaric oxygen therapy. At the end of the follow up period, 11 patients demonstrated complete remission, while in 14 cases amelioration and in 5 no significant improvement was noted.

CONCLUSION

Based on differences in age at presentation, clinical appearance and course, radiology and histology, a subclassification into early and adult onset primary chronic osteomyelitis has been established. Cases with purely mandibular involvement should further be distinguished from cases associated with other syndromes.

Implant site development and alveolar bone resorption patterns

Resorption of the alveolar ridges after tooth extraction can mandate site development (preparation) by augmentation, grafting, or both before implants can be placed. The fabrication of successful implant prostheses generally can be accomplished only if the artificial teeth are placed in the same position as was occupied by the natural teeth they are replacing. A knowledge of resorption patterns is necessary for satisfactory implant placement.

Buccal alveolar exostoses: prevalence, characteristics, and evidence for buttressing bone formation

BACKGROUND

Buttressing bone formation has been described as the development of thickened or exostotic buccal alveolar bone in response to heavy occlusal forces. Little supporting evidence for this model has been found in previous literature, however, and there is little seen on the prevalence or characteristics of buccal alveolar exostoses.

METHODS

A sample of 416 selected teeth and investing bone in 52 modern skeletal specimens at the National Museum of Natural History were examined. Two measures of heavy occlusal function--periodontal ligament (PDL) width and occlusal attrition--were analyzed for their relationship to three parameters of buccal alveolar bone (exostoses, lipping, and overall thickness).

RESULTS

Buccal alveolar bone enlargements were found in 25% of all teeth examined: 18% were expressed as marginal bony lippings and 7% as buccal exostoses. Exostoses were mainly seen around maxillary molars and bicuspids, especially in males, while lippings were seen in molars, bicuspids, and mandibular incisors, with even gender distribution. When findings were controlled for arch and tooth type, no significant correlations were found between wider PDL spaces or occlusal attrition and exostotic, lipped, or thicker alveolar bone.

CONCLUSIONS

These results indicate a lack of anatomic evidence for the theory of buttressing bone formation and suggest that other factors may be of greater importance in the etiology of buccal bone enlargements. Incidentally, no correlation was found between widened PDL spaces or severe occlusal attrition and the presence of cervical loss of tooth structure, which casts doubt on the currently popular concept of abfraction.

Florid cemento-osseous dysplasia in a young Chinese man. Case report

Florid cemento-osseous dysplasia refers to a group of fibro-osseous lesions which are exuberant, multiquadrant and arise from the tooth-bearing area of the jaws. It is classically described as a condition occurring almost exclusively in middle-aged black women. A case of florid cemento-osseous dysplasia occurring in a young Chinese male is reported which was rare in regard to race and sex. This 20 year old Chinese man presented with huge symmetrical bony lesions in all four quadrants of the jaws. Clinical presentation, radiological findings and histological features of the excised specimens are described. Treatment of the lesions was unusual. Curettage was first done with minimal benefit and it was followed by mandibular recontouring to improve facial appearance. The outcome of these procedures will be discussed.

Differential diagnosis of oral enlargements in children

The purpose of this article is to review soft tissue and bony enlargements that typically occur in the oral and perioral region of children. In order to organize these lesions into a thorough but comprehensible format, the principles of differential diagnosis must be used. All oral enlargements are broadly classified as soft tissue or bony abnormalities. Determination of the specific lesion category is based primarily on a prominent feature that demonstrates the nature of the lesion, followed by the secondary clinical features and any contributory patient information. Classification of exophytic soft tissue entities includes: papillary surface enlargements, acute inflammatory enlargements, reactive hyperplasias, benign submucosal cysts and neoplasms, and aggressive and malignant neoplasms. Bony enlargements of the maxilla and mandible are divided into three categories: inflammatory lesions, benign cystic and neoplastic lesions, and aggressive and malignant lesions. This extensive topic is summarized on flow charts for easy reference with emphasis on grouping together lesions with common characteristics.

Osteomyelitis of the jaws

Osteomyelitis is described as an inflammation of bone and bone marrow that may develop in the jaws following a chronic odontogenic infection or for a variety of other reasons. This situation may be acute, sub-acute or chronic, resulting in a totally different clinical picture.

A retrospective analysis of 367 cystic lesions of the jaw--the Ulm experience

Out of 846 cyst-like lesions of the jaws, 367 cases were retrieved from the files of the Department of Oral and Maxillofacial Surgery at the University of Ulm and classified according to the new World Health Organization's classification for odontogenic tumours and cysts. Radicular and residual cysts comprised 56.9%, dentigerous cysts 21.3%, odontogenic keratocysts 10.6%, unicystic ameloblastomas 4.1%, nasopalatine duct cysts 2.7%, glandular odontogenic cysts 1.6% and paradental cysts, traumatic bone cysts, calcifying odontogenic cyst and lateral periodontal cyst each less than 1% of the sample. Nearly one third of the specimens were obtained from military patients; despite an expected bias towards young males, unicystic ameloblastomas presented one and a half decades later than is generally reported.

Fibro-osseous lesions of the jaws

In the first volume of the Journal of Oral Surgery, Dr G. Victor Boyko presented a case of osteofibroma of the mandible associated with leontiasis ossea of the skull (Boyko GV: J Oral Surg 1:100, 1943). The patient was a 32-year-old white woman who had complaints of right mandibular enlargement and a prominence of the right frontal and temporal areas of uncertain duration in August 1939. Mandibular radiographs showed an area of reduced radiodensity. Skull films showed a marked increase in density of the inferior part of the right temporal region and of the frontal bone, with evidence of both bone destruction and proliferation in the inferior frontal and orbital regions. A mandibular biopsy was reported as osteofibroma. The patient was kept under observation for 8 months after the biopsy, with little change in her condition. A course of deep x-ray therapy was then delivered to the mandibular lesion. She subsequently developed a pathologic fracture that was treated by maxillomandibular fixation. The fracture stabilized and at the last clinical examination, in June 1942, the patient had a union with good functional occlusion and was reported to be in good mental and physical condition.

Central giant cell lesions of the jaws. A clinical, radiologic, and histopathologic study

The histology, radiographs, and follow-up information for 142 cases of central giant cell lesions of the jaws were reviewed in an effort to determine which, if any, microscopic features could be correlated with clinical behavior. The majority of these lesions were asymptomatic and relatively innocuous. However, some displayed a more aggressive clinical course characterized by root resorption, pain or paresthesia, and cortical perforation. The over-all recurrence rate in the 142 cases was 16%. Adequate follow-up information (mean, 48 months) was only obtained for 47 patients, and 23 (46%) of these experienced one or more recurrences. Statistically significant histologic differences in distribution of giant cells and frequency of osteoid within the lesions were found in lesions that recurred as opposed to those that did not. The concept that giant cell lesions of the jaws are not totally different entities from giant cell tumors is discussed.

[Histopathology of odontogenic cysts]

Odontogenic cysts present problems of diagnosis, radiology and histopathology. This review of the literature considers the current system of classification and reveals a level of agreement with regard to the major categories of cysts. The term "developmental odontogenic cyst" embraces primordial cysts (or odontogenic keratocysts), gingival cysts (newborn and adult), lateral periodontal cysts, eruption and dentigerous cysts and odontogenic calcified cysts (Gorlin cysts). "Inflammatory odontogenic cyst" includes: the radicular cysts and its etiological variance, residual cysts, inflammatory collateral cysts, periodontal cysts and inflammatory follicular cysts. Clinical symptoms are not in themselves sufficient to differentiate between several of the different categories. A combination of clinical and histopathological evidence is essential if a definitive diagnosis is to be achieved and the risk of carcinoma eliminated. Developmental or inflammatory cysts arise from cells involved in the development of the dental organ.

Clinical and histopathological study of fibro-osseous lesions of the jaws

Seventy-two cases of benign fibro-osseous lesions of the jaws were reassessed, and a modified classification is proposed that may be helpful in their understanding and management. The anatomical distribution of these cases is described and compared to previously reported cases. The histogenesis of each particular lesion is also discussed. Correlative analysis of histopathologic and oral radiographic features is essential for definitive diagnosis.

Expression of cytokeratins in odontogenic jaw cysts: monoclonal antibodies reveal distinct variation between different cyst types

Immunostaining with monoclonal antibodies was used to study and compare the cytokeratin content of odontogenic cysts and normal gingival epithelium. Two monoclonal antibodies, PKK2 and KA1, stained the whole epithelium in all cyst samples. In gingiva, PKK2 gave a suprabasal staining and KA1 reacted with all epithelial cell layers. Antibodies PKK1, KM 4.62 and KS 8.12 gave a heterogeneous staining in follicular and radicular cysts. In keratocysts and in gingiva PKK1 and KM 4.62 reacted mainly with basal cells and KS 8.12 gave a suprabasal staining. Antibodies reacting with the simple epithelial cytokeratin polypeptide No. 18 (PKK3, KS 18.18) recognized in gingiva only solitary cells compatible with Merkel cells. In a case of follicular ameloblastoma a distinct staining of tumor epithelium was revealed with these antibodies. In 2 follicular cysts, but not in other cyst types, a layer of cytokeratin 18-positive cells was revealed. KA5 and KK 8.60 antibodies, reacting exclusively with keratinizing epithelia, including normal gingiva, gave no reaction in radicular cysts, keratocysts and ameloblastoma. Two of the follicular cysts, were negative for PKK3 and KS 18.18, but reacted strongly with KA5 and KK 8.60. The present results show that odontogenic jaw cysts have distinct differences in their cytokeratin content. With the exception of some follicular cysts, they lack signs of keratinizing epithelial differentiation. Only follicular cysts appear to share with some types of ameloblastoma the expression of cytokeratin polypeptide No. 18.

Fibro-osseous lesions of the jaws

During the 15 years since the author's 1970 paper on fibro-osseous lesions of the jaws, the subject has continued to interest the clinician and pathologist. Several new entities have been delineated during this period, and new concepts and controversies regarding the diagnosis and management of these lesions have arisen. A classification of fibro-osseous jaw lesions that the author has found to be workable is presented, and criteria for their diagnosis and management based on the authors' experience is discussed.

Residual alveolar ridge atrophy: classification and influence of facial morphology

A method for grading residual alveolar ridge atrophies of edentulous maxillae and mandible has been devised for men and women. Comparisons were made in women and in men between the degree of atrophy and the vertical facial morphology. The study suggests some relationship between the total facial height (TFH), the vertical facial type determined by the Frankfort horizontal mandibular plan (FMA), and the atrophy of the alveolar ridges, especially for the mandible. Certain practical applications of these findings were suggested.