Intraosseous mucoepidermoid carcinoma: a review of the diagnostic imaging features of four jaw cases.

The purpose of this case series is to present the common features of intraosseous mucoepidermoid carcinoma (IMC) of the jaws in plain film and CT imaging. Two oral and maxillofacial radiologists reviewed and characterized the common features of four biopsy-proven cases of IMC in the jaws in plain film and CT imaging obtained from the files of the Department of Oral Radiology, Faculty of Dentistry, University of Toronto, Toronto, Canada. The common features are a well-defined sclerotic periphery, the presence of internal amorphous sclerotic bone and numerous small loculations, lack of septae bordering many of the loculations, and expansion and perforation of the outer cortical plate with extension into surrounding soft tissue. Other characteristics include tooth displacement and root resorption. The four cases of IMC reviewed have common imaging characteristics. All cases share some diagnostic imaging features with other multilocular-appearing entities of the jaws. However, the presence of amorphous sclerotic bone and malignant characteristics can be useful in the differential diagnosis.

Central giant cell granuloma of the mandibular condyle: a case report and review of the literature.

Central giant cell granuloma (CGCG) is a benign intraosseous lesion. The true nature of this lesion is controversial and remains unknown; the three competing theories are that it could be a reactive lesion, a developmental anomaly or a benign neoplasm. Furthermore, the actual aetiology of CGCG is still unclear, although inflammation, haemorrhage and local trauma have all been suggested; it has also been hypothesized that CGCG may have a genetic aetiology. Lesions central to the mandibular condylar head are very rare, with only three documented cases in the English language literature, none of which elaborates on the CT features. In this case report, a 31-year-old male patient complaining of a left pre-auricular mass underwent radiographic investigation. CT images revealed a lesion central to the mandibular condyle and demonstrated features that were highly suggestive of CGCG. The patient underwent surgical curettage, and the subsequent histopathological examination confirmed the diagnosis of CGCG. 3 years after the procedure the patient presented with a recurrence and underwent complete resection of the mandibular condyle with immediate reconstruction. This report presents CT characteristics of a rare occurrence of CGCG of the mandibular condyle, compares it with other published cases and poses the question of the role of radiology in predicting the degree of aggressive behaviour of these lesions before surgery.

Gorham's disease of the maxilla: a case report.

A case of Gorham's disease in the maxilla of a 56-year-old male patient is described. The clinical presentation, radiographic and histopathological features and treatment are presented. A discussion of the current understanding of this rare disease, based on review of the literature, is offered.

The occurrence of keratocystic odontogenic tumours in nevoid basal cell carcinoma syndrome.

OBJECTIVES: This retrospective study reviews the occurrence of keratocystic odontogenic tumours (KOTs) in nevoid basal cell carcinoma syndrome (NBCCS) patients seen in the Oral and Maxillofacial Radiology Special Procedures Clinic in the Faculty of Dentistry at the University of Toronto. METHODS: This study examines the number and radiographic features of KOTs identified in 11 NBCCS patients who presented with 43 KOTs between January 1989 and 30 June 2007 on plain film radiographs and CT. RESULTS: Regression analysis revealed a statistically significant (P < 0.01) relationship between the age at first KOT occurrence and the total number of lifetime KOTs (r = -0.78). Of the KOTs identified, 25 developed in the mandible and 18 developed in the maxillae. The majority of these were associated with a change in either the size or shape of the follicular space, and both plain film radiography and CT were equally effective at demonstrating these changes. CT was, however, more effective at demonstrating endosteal scalloping of cortical bone than plain film radiography (P < 0.001) while the opposite was true for showing tooth displacement (P < 0.01). For patients imaged with both plain radiography and CT (29 KOTs), 5 KOTs were detectable only by CT. CONCLUSIONS: Our results suggest that there should be early and frequent monitoring of NBCCS patients for the development of KOTs in youth and adolescence, and that CT imaging should play an important role in these investigations.

A retrospective study assessing the incidence, risk factors and comorbidities of pamidronate-related necrosis of the jaws in multiple myeloma patients.

BACKGROUND: Bone necrosis of the jaws is a newly recognized complication associated with the use of bisphosphonates. The true incidence of this complication is unknown and the pathophysiology is controversial. The purpose of this study was to determine the incidence of jaw necrosis among a homogeneous population of multiple myeloma patients receiving the bisphosphonate pamidronate, to investigate risk factors and comorbidities that increase the risk and to characterize the radiographic changes on conventional dental radiographs in terms of type and frequency. MATERIALS AND METHODS: The study was a retrospective review of medical and dental charts and databases in the medical oncology and dental departments at Princess Margaret Hospital, a tertiary cancer centre in Toronto. Two patient sample sizes were used, n = 655 for assessment of the incidence and n = 120 for analysis of the risk factors and comorbidities. RESULTS: The incidence was estimated at 3.2% (95% confidence interval). The following risk factors were found to be statistically significant: longer duration of pamidronate therapy (P < 0.001), dental extractions (P < 0.001), cyclophosphamide therapy (P < 0.014), prednisone therapy (P < 0.014), erythropoietin therapy (P = 0.006), low hemoglobin levels (P < 0.001), renal dialysis (P < 0.016) and advanced age (P < 0.001). Radiographic changes produced by the necrotic bone were less evident than the clinically exposed bone.

Methods of determining the relationship of the mandibular canal and third molars: a survey of Australian oral and maxillofacial surgeons.

BACKGROUND: Surgical extraction of third molars is one of the most common oral and maxillofacial surgical procedures performed and may have a number of associated complications. One of these complications is inferior alveolar nerve (IAN) dysaesthesia or impairment of sensory perception (including paraesthesia and/or anaesthesia). Previous studies assume that most clinicians use various combinations of nine radiologic criteria on panoramic radiographs as indicators of the relationship and, therefore, predictors of the risk of postoperative dysaesthesia. Our study assessed both the current radiologic modalities and assessment criteria used by Australian oral and maxillofacial surgeons when determining the proximity of mandibular canal to third molars. METHODS: A survey of all surgeon members of the Australian and New Zealand Association of Oral and Maxillofacial Surgeons (ANZOMS) practising in Australia was undertaken. RESULTS: Of the 105 questionnaires sent to surgeons, 72 responses (68 per cent) were returned. All surgeons reported using the panoramic radiograph but only 25 per cent considered it sufficiently accurate in determining the relationship between the mandibular canal (MC) and the third molar root, while 61 per cent of surgeons use CT for this purpose but the average frequency of use was very low (five per cent). This study also revealed that the nine radiologic criteria on a panoramic radiograph are used to varying extents by Australian surgeons. Nearly all surgeons use 'change in MC direction' and 'MC narrowing' to determine and close relationship. Thirty-one per cent used superimposition of the MC and the root of the third molar alone and 24 per cent used appearance of contact of the root with the MC alone in the absence of any other radiologic criteria to indicate close or intimate relationship. CONCLUSION: Further research is required to determine the accuracy and observer agreement or reliability of using the nine panoramic characteristics, to determine this relationship and whether the presurgical determination of proximity and position (buccal or lingual) of the canal utilizing CT has any usefulness in determining the surgical protocol or affect on postoperative morbidity.

Periapical health and treatment quality assessment of root-filled teeth in two Canadian populations.

AIM: The prevalence of apical periodontitis (AP) and the quality of root fillings and restorations were determined in two Canadian populations differing in avail-ability of endodontists. METHODOLOGY: Radiographs of first-time university patients aged 25-40 years in Toronto and Saskatoon were examined for missing teeth, presence and standard of root fillings, standard of restoration, and AP according to the Periapical Index. Patients with root-filled teeth were invited for clinical examination and interview to inspect the restorations, and to reveal the providers of endodontic treatment and reasons for extractions of missing teeth. Chi-square and independent t-tests interpreted at the 5% significance level were used to examine associations between the prevalence of AP in root-filled teeth and the standard of the root filling, restoration, and providers of treatment. RESULTS: Proportion of patients with root-filled teeth was significantly higher (P < 0.001) in Toronto than in Saskatoon (39 and 26%, respectively). Presence of AP about root-filled teeth (44% in Toronto, 51% in Saskatoon) was significantly associated with poor density (OR = 2.7) short (OR = 2.4) and long (OR = 2.8) root fillings, and with poor radiographic quality of the restoration (OR = 1.7) Prevalence of AP did not differ significantly between teeth treated by generalists and endodontists. CONCLUSIONS: The prevalence of AP in root-filled and untreated teeth was comparable to that reported in previous methodologically compatible studies. The quality of both the root filling and the restoration were found to impact on the periapical health of root-filled teeth, with the impact of the restoration being most critical when the quality of the root filling was adequate.

Managing the posterior mandible of partially edentulous patients with short, porous-surfaced dental implants: early data from a clinical trial.

Forty-eight Endopore dental implants were placed in the posterior mandibles of 24 partially edentulous patients. Seventeen of these implants replaced premolar teeth, while 31 replaced molars. Only 7-mm and 9-mm implants were used, and the majority of prosthetic restorations (83%) were single crowns. After a mean functional time of 32.6 months (range, 8.2 to 50.3 months), the implant survival rate was 100% and assessment of available radiographic data showed minimal to no crestal bone loss.

A prospective human clinical trial of Endopore dental implants in restoring the partially edentulous maxilla using fixed prostheses.

This is the first report of a group of 50 partially edentulous patients who received a total of 151 Endopore dental implants in the maxilla. A mean implant length of 8.7 mm was used, and 76.8% of implants were placed in the posterior maxilla. At re-entry, all implants appeared to be osseointegrated and were used to support fixed prostheses. Approximately half of the crowns (57%) in these prostheses were splinted to one another, while the remainder (43%) were not. At the time of this report, the mean functional time was 34.6 months and the cumulative survival rate was 97.3% (4 implants had failed). Analysis of carefully standardized sequential radiographs indicated no significant changes in mean crestal bone levels between baseline and any of the examination times (after 6 months, 1 year, and 2 years in function). There were no detectable correlations between crestal bone loss and the factors implant length (7, 9, or 12 mm); implant diameter (3.5, 4.1, or 5.0 mm); implant position anteriorly or posteriorly in the maxilla; or whether or not the implant-supported crowns were splinted.

The use of computed tomography to define zygomatic complex position.

PURPOSE: The purpose of this study was to analyze the use of midline references and landmarks to assess the position of the zygomatic complex relative to the cranial base, and to test the reliability of these measurements in assessing facial symmetry. METHODS: Direct skull measurements were compared with measurements made on computed tomography (CT) images. The effect of CT scanner error, technologist error, gantry angle error, error of skull inclination, and error due to the presence of titanium rigid fixation hardware were assessed. To test observer variation and the effect of each level of error, 4 blinded bilateral measurements were repeated 3 times by 5 observers on both dry skull and CT scans. A mixed effect analysis of variance model then assessed for effect of method of measurement (dry skull vs CT), observer, CT scanner, technologist, gantry angle, skull inclination, and rigid fixation. RESULTS: A total of 2,040 measurements were made. Measurements for zygomatic complex posterior and anterior width and height were reliable and had an interobserver variations of 0.02 +/- 0.03 mm, 0.5 +/- 0.4 mm, and 0.37 +/- 0.3 mm, respectively. The difference between dry skull and CT assessment for the 3 reliable measurements was 1.2 +/- 0.3 mm, 0.44 +/- 0.4 mm, and 1.1 +/- 0.5 mm, respectively. The errors produced by the CT scanner, technologist, and rigid internal fixation hardware were not clinically significant. The measurements were not sensitive to gantry angle and skull inclination changes of 10 degrees or less. A fourth measurement assessing zygomatic complex projection was found not to be accurate or reliable. CONCLUSIONS: These findings suggest that the 3 CT scan measurements describing the position of the zygomatic complex relative to the cranial base are clinically useful.

Five- to six-year results of a prospective clinical trial using the ENDOPORE dental implant and a mandibular overdenture.

This report is an update on a group of 46 clinical trial patients who each received 3 free-standing Endopore dental implants placed using a 2-stage surgical approach in the anterior mandible. After an initial healing interval of 10 weeks, the implants were used in each case to retain an over-denture, and at the time of the report, all patients had passed 5 years of continuous function. The 5-year cumulative "survival" rate based on a life table analysis was 93.4% and this remained unchanged after 6 years. The 5-year "success rate" was 83.3% when assessed qualitatively with the published criteria of others using a four-field table analysis categorizing every implant in the study as one of "Grade 1 Success", "survival", "unaccounted for" or "failure". Modified periodontal parameters verified continued peri-implant soft tissue health. No implant still in function had more than 1.8 mm cumulative bone loss during the first 5 years of function. These results provide clear evidence that Endopore implants despite their short lengths function at least as well as other dental implant designs used in much longer lengths.

Use of the Endopore dental implant to restore single teeth in the maxilla: protocol and early results.

This report outlines the experimental, surgical, and prosthodontic protocols for a prospective clinical trial using the Endopore dental implant to replace single maxillary teeth. Twenty patients (10 male, 10 female) ranging in age from 30 to 60 years each received one implant (mean length 10.1 mm), which, after an initial healing period of 4 months, was restored with a single crown. Records collected included radiographs, Periotest mobility measurements, supragingival Plaque Index, and an assessment of peri-implant soft tissue health using pocket probing depths, sulcular bleeding following probing, and probing attachment levels. Radiographs were exposed at predetermined intervals following crown placement (1 and 6 months, and then yearly) in a standardized procedure using a specialized filmholder that attaches to each implant after removal of the crown. At the time of this preliminary report, all of the 20 implants placed had been uncovered and were in function; 16 of the implants had been in function for 6 months or more, 14 had passed 1 year of function, and 3 had passed the 2-year function point. There have been no failures to date.

Imaging techniques and image interpretation for dental implant treatment.

PURPOSE: This article reviews the literature on radiographic imaging techniques and image interpretation for dental implant treatment. MATERIALS AND METHODS: MEDLINE was used to identify published peer-reviewed literature for this report. RESULTS: Radiographic images are indispensable in the evaluation of osseous structures when planning treatment for dental implants. Potential bone sites for implant placement can be assessed clinically by means of palpation or probing through the mucosa; however, diagnostic imaging provides the best means for indirectly measuring bone dimensions. After healing of the implant site, the application of radiology is useful to verify the amount of bone adjacent to the implant and that the transmucosal abutments fit the implant. Upon completion of the implant prosthesis, radiology may be used to monitor initial and long-term success of implant treatment. CONCLUSION: Recommendations for the application of radiology over the course of treatment are made for various implant cases ranging from the overdenture to the single-tooth implant.

Influence of the addition of restorations on the diagnosis of caries from digitized bitewing radiographs.

OBJECTIVES: The purpose of this study was to assess the influence of additional caries and restorations on the detection of caries on the same radiograph. STUDY DESIGN: Six participants examined five series of four radiographs in which natural carious lesions were present. Each series consisted of the same image with progressively more restorative treatment digitally painted on. The films were randomly presented to the observers who examined the films for the presence and depth of carious lesions. The observers were not informed that the 20 films were disguised versions of the same original five radiographs. RESULTS: The number of carious lesions reported by the six observers did not increase despite the apparent increased restorative intervention viewed on the radiographs. CONCLUSIONS: The complexity of restorative care does not affect observers' ability to correctly detect approximal carious lesions.

A comparison of radiographic bone height and probing attachment level measurements adjacent to porous-coated dental implants in humans.

The changes in crestal bone height observed in standardized radiographs of porous-coated dental implants after 3 to 4 years of function in the support of mandibular overdentures is reported for a group of 48 completely edentulous patients. Possible correlations between bone height and each of probing attachment level, Plaque Index, and Sulcular Bleeding Index were investigated. Mean bone loss values were determined to be 0.43 mm in year 1, decreasing to 0.17 mm and 0.13 mm in years 2 and 3, respectively. During year 4, there was an apparent mean gain of 0.05 mm. While the mean mucosal tissue thickness (1.3 mm) was similar to that reported by other investigators, it was not possible to show a correlation between bone height and probing attachment level. Likewise, correlations between bone height and Plaque Index or between bone height and Sulcular Bleeding Index could not be demonstrated.

Non-invasive computed tomography and three-dimensional reconstruction of the dentition of a 2,800-year-old Egyptian mummy exhibiting extensive dental disease.

A second CT scan of the mummy Djedmaatesankh, which is housed in the Royal Ontario Museum, Toronto, Ontario, has been undertaken after an interval of some 15 years. The image data set of her dentition and the associated tissues acquired from 3 mm thick x 3 mm spacing slices was transferred to an ISG Allegro work station where two-dimensional reformats and three-dimensional reconstructions were produced. This non-invasive examination provided information on dental disease that is, in a number of respects, an advance on that which previously could be obtained from mummies by the traditional methods of visual inspection after unwrapping and by two-dimensional radiography. The two- and three-dimensional images reveal that: three molars are missing and the right maxillary canine is impacted; the rest of the dentition is afflicted by severe attrition, caries and periodontal disease; and, of the 28 teeth present in the mouth, 24 exhibit exposure of their dental pulps and 18 are afflicted by periapical lesions including five that could have contributed to a large secondarily infected radicular cyst. The cyst have displaced the maxillary antrum and enlarged the maxilla on its lateral aspect and the vault of the palate on its medial aspect. Pus from the cyst may have drained through five different sinuses. In life, Djedmaatesankh's widespread dental infection probably caused her considerable pain, personal distress and malaise, and possibly resulted in her death.

A central giant cell granuloma influenced by pregnancy.

A case of a 17-year-old patient with exacerbation of a central giant cell granuloma of the mandible during pregnancy is reported. The possible relationship of the giant cell lesion to a pre-existing fibrous dysplasia is considered although there was lack of histological evidence.