Dentomaxillofacial radiology in Australia and dentist satisfaction with radiology reports.

BACKGROUND: Dentomaxillofacial Radiology (DMFR) is comprised of the smallest cohort of specialists in Australia. A survey was undertaken to assess awareness of DMFR, radiology reporting and referring protocols as well as dental practitioners' satisfaction with their radiology reporting arrangements. METHODS: An original online survey created using Checkbox† was sent to dental practitioners. The survey was promoted on Australian-based dental Facebook forums and emailed to targeted members via Australian professional dental associations. RESULTS: A total of 399 responses were received, with over 80% of respondents aware of DMFR as a specialty. Approximately 40% of practitioners were self-reporting their imaging. There was correlation between increased satisfaction with external reporting and utilization of DMFR services and decreased satisfaction with medical radiology services. More than 90% of general dentists and greater than 85% of dental specialists prefer DMFR reports to medical radiology reports. Approximately 80% of practitioners believed that their satisfaction would change positively if they had access to a DMFR report. CONCLUSION: The research indicates a high degree of self-reporting or non-reporting by dental practitioners. There is low satisfaction with external reporting performed by Medical Radiologists primarily due to a lack of dental knowledge or detail and a preference for DMF Radiology reports.

Comparative adoption of cone beam computed tomography and panoramic radiography machines across Australia.

BACKGROUND: The aim of the present study was to assess the current adoption of cone beam computed tomography (CBCT) and panoramic radiography (PR) machines across Australia. METHODS: Information regarding registered CBCT and PR machines was obtained from radiation regulators across Australia. The number of X-ray machines was correlated with the population size, the number of dentists, and the gross state product (GSP) per capita, to determine the best fitting regression model(s). RESULTS: In 2014, there were 232 CBCT and 1681 PR machines registered in Australia. Based on absolute counts, Queensland had the largest number of CBCT and PR machines whereas the Northern Territory had the smallest number. However, when based on accessibility in terms of the population size and the number of dentists, the Australian Capital Territory had the most CBCT machines and Western Australia had the most PR machines. The number of X-ray machines correlated strongly with both the population size and the number of dentists, but not with the GSP per capita. CONCLUSIONS: In 2014, the ratio of PR to CBCT machines was approximately 7:1. Projected increases in either the population size or the number of dentists could positively impact on the adoption of PR and CBCT machines in Australia.

Central calcifying epithelial odontogenic tumour in the posterior maxilla: a case report.

The calcifying epithelial odontogenic tumour (CEOT), or Pindborg tumour, is a rare, benign odontogenic tumour. CEOT is usually asymptomatic and an incidental radiological finding, often presenting as a mandibular radiolucency with flecks of calcific material. We report an unusual case of CEOT in the left posterior maxilla of a 46-year-old male that was associated with an unerupted tooth. The tumour in this case caused non-specific sinus symptoms and appeared radiographically similar to an odontoma or ossifying fibroma due to its dense calcific contents. Diagnosis was confirmed histologically following surgical removal of the lesion, which showed classic CEOT histomorphology. We report this case to highlight the unusual clinico-radiologic presentation and illustrate the diagnostic difficulties that can occur with radiolucent and/or radiopaque lesions in the jaws.

Morphology of the greater palatine grooves of the hard palate: a cone beam computed tomography study.

BACKGROUND: There is increasing frequency of dentoalveolar and palatal implants placed in the posterior maxilla for prosthodontic and orthodontic purposes. The purpose of this study is to provide information on the location and morphology of the greater palatine grooves (GPG) in the hard palate and to promote awareness of this structure. METHODS: Eighty-nine cone beam computed tomography (CBCT) scans were analysed for the presence of a groove, crest or bridging. RESULTS: This study on the morphology of the GPG in the maxillary first and second molar regions showed three distinct appearances: (1) no palatal groove; (2) one palatal groove; (3) two palatal grooves. The detection frequency of no palatal groove in the first molar region was 60%, 34% had one groove and 6% having two grooves. The detection frequency of no palatal groove in the second molar region was 72%, 26% had one groove and 2% had two grooves. The number of crests in the first and second molar regions ranged from 0 to 3. CONCLUSIONS: The present study demonstrates a great variation in morphology of the GPG of the hard palate. Knowledge of the GPG will decrease possible complications of implant surgery, particularly palatal implant surgery and to not confuse the GPG with pathology.

The growth of Medicare rebatable cone beam computed tomography and panoramic radiography in Australia.

BACKGROUND: There is a lack of objective data documenting the growth of cone beam radiology in Australia. Medicare rebates for cone beam computed tomography (CBCT) scans have been available since 1 July 2011. The aim of this study was to examine the Medicare data on the use of CBCT in order to quantify the growth of this technology over a three-year period and to assess if the growth of CBCT was impacting upon the use of dental panoramic radiology. METHODS: The Medicare dataset was accessed, and data relating to the number and distribution of CBCTs and panoramic radiographs (PRs) were extracted. The data were broken down by state and territory, as well as by age group and gender of the patient, for the financial year periods July 2011 to June 2012, July 2012 to June 2013 and July 2013 to June 2014. Items relating to PRs were also extracted for the periods 2005-2008 and 2008-2011. RESULTS: In the period July 2011 to June 2014, a total of 226 232 CBCTs and 2 881 351 PRs were rebated through Medicare. The rate of CBCT services provided per 100 000 population increased by 42.3% over the three-year period, whereas the rate of PRs remained fairly constant. From the age group 5-14 years through to 55-64 years, females received more CBCTs and PRs than males. The total number of PRs rebated through Medicare increased slightly over each previous three-year period (2005-2008 and 2008-2011). CONCLUSIONS: There has been rapid growth of the use of CBCT over a three-year period, most marked in the State of Victoria. The higher number of CBCT examinations in females across almost all age groups, but most notably in the 15-24 years age group, raises questions about clinical decision making in the selection of cone beam imaging. There was little evidence that CBCTs were being used as a substitute for PRs, except for a small but consistent drop in the number of PRs being requested for diagnosis of surgically related dental conditions.

Age-related changes in maxillary and mandibular cortical bone thickness in relation to temporary anchorage device placement.

BACKGROUND: The aim of this study was to investigate the correlation between alveolar bone cortical thickness (ABCT) and age in the maxillae and mandible in humans. This information could then be translated into clinical application with temporary anchorage devices (TADs) in orthdontics. METHODS: Samples comprised 82 post-mortem CT datasets (41 males and 41 females) aged between 11 to 50 years, and were divided into five different age groups and gender. Alveolar ABCT was measured in the labial/buccal and palatal/lingual sides of the incisor, canine, premolar, molar and tuberosity/retromolar regions of the maxillae and mandible. Correlations between ABCT and age and gender were analysed with linear regression analysis. RESULTS: Strong correlation between ABCT and age was found for the maxilla on the labial side of the maxillary incisor region (p < 0.001). On the palatal aspect, significant correlations between ABCT and age were found in the maxillary incisor and maxillary premolar regions (p = 0.01 and p = 0.047 respectively). Significant correlation between ABCT and gender was found only at the buccal aspect of the maxillary molar region (p = 0.022). In the mandible, a statistically significant correlation between ABCT and age was found in the cortical bone of the labial side of the mandibular incisor region (p = 0.017). However, statistically significant negative correlation between ABCT and age was found in the mandibular canine region (p = 0.033). The only site to demonstrate a significant difference in change in ABCT with age between males and females was the lingual side of the retromolar region, in which female ABCT increased more than in males (slope = 0.015). CONCLUSIONS: There is minimal clinically significant correlation between ABCT and age at the alveolar bone level. Although investigations show statistically significant correlations, these may not be clinically significant as those regions are not ideal for anchorage reinforcement with TADs in orthodontic practice.

Parosteal osteosarcoma: report of a case and review of the literature.

Parosteal osteosarcoma is a rare malignancy of the bone that usually arises in the long bones. Involvement of the oral cavity is rare. Only 12 cases of intraoral parosteal osteosarcoma have been reported in the English language literature. This paper defines the major clinical, radiographic and histologic features of parosteal osteosarcoma and illustrates these with a case of a 33-year-old male presenting with a three-month history of a painless enlarging lump in the right maxilla. A critical and comprehensive review of the English language literature is also provided.

Chronic recurrent multifocal osteomyelitis involving the mandible: case reports and review of the literature.

Chronic recurrent multifocal osteomyelitis (CRMO) is an aseptic inflammatory disorder of unknown cause occurring in children and adolescents. It is characterized by multifocal bone lesions with pain and swelling recurring over months to years. Lesions usually involve the metaphyses of the long bones and involvement of the jaw is rare. The clinical presentation, radiographic appearance and histology of a case of CRMO involving the mandible in an 8-year-old girl are documented. The radiographic appearance of another three cases is also described.

Imaging of craniofacial fibrous dysplasia.

Fibrous dysplasia is a relatively common disorder of bone. It may affect the bones of the face and skull and, in so doing, produce a wide variety of clinical presentations. Plain film assessment of craniofacial fibrous dysplasia may be difficult because of varying appearances and complex, overlapping structures. The MRI appearances of fibrous dysplasia are often non-specific and may be confusing. Findings on CT are also variable, but more commonly lead to a specific diagnosis. This is because of the characteristic ground-glass appearance of woven bone, seen on CT in most if not all cases of craniofacial fibrous dysplasia.

Implant radiography and radiology.

The practitioner placing dental implants has many options with respect to pre-implant radiographic assessment of the jaws. The advantages and disadvantages of the imaging modalities currently available for pre-implant imaging are discussed in some detail. Intra-oral and extra-oral radiographs are generally low dose but the information provided is limited as the images are not three-dimensional. Tomography is three-dimensional, but the image quality is highly variable. Computed tomography (CT) has been the gold standard for many years as the information provided is three-dimensional and generally very accurate. However, CT examinations are expensive and deliver a relatively high radiation dose to the patient. The latest imaging modality introduced is cone beam volumetric tomography (CBVT) and this technology is very promising with regard to pre-implant imaging. CBVT generally delivers a lower dose to the patient than CT and provides reasonably sharp images with three-dimensional information. A comparison between CT and CBVT is provided. Magnetic resonance imaging is showing some promise, but the examinations are not readily available, generally expensive and bone is not well imaged. Magnetic resonance imaging is excellent for demonstrating soft tissues and therefore may be of great use in identifying the inferior dental nerve and vessels. All of the above technology is of little value if the information required is not obtained and so information is also provided on imaging of some of the vital structures. Of particular interest is the inferior dental canal, incisive canals of the mandible, genial foramina and canals, maxillary sinus and the incisive canal and foramen of the maxilla.

Narrowing of the inferior dental canal in relation to the lower third molars.

OBJECTIVES: To assess narrowing of the inferior dental canal in the lower third molar regions using computed tomography (CT) and to determine the value of radiographic markers on rotational panoramic radiographs in assessing the true relationships of the inferior dental canal. METHODS: Patients referred for CT assessment of impacted lower third molars were used in this study. The lower third molars were assessed using CT to determine the position and morphology of the inferior dental canal relative to the roots and the cortical plates. The radiographic markers on rotational panoramic radiographs were correlated with the CT findings when rotational panoramic radiographs were available. RESULTS: The patients referred had 202 lower third molars. Inferior positioning of the inferior dental canal was the most common location on CT. Narrowing of the inferior dental canal was found in relation to the lower third molars in 66.8% of cases. The chance of narrowing of the inferior dental canal as shown using CT increased when at least one of the radiographic markers, superimposition, narrowing, deviation or reduction in density was present on the rotational panoramic radiograph. Deviation of the inferior dental canal on rotational panoramic radiographs was found to be the most significant predictor of narrowing of the inferior dental canal and a close relationship to the roots, as shown in CT. CONCLUSIONS: Narrowing of the inferior dental canal is a common finding when impacted lower third molars are assessed using CT. On rotational panoramic radiographs deviation of the inferior dental canal is the best predictor of narrowing of the inferior dental canal and a close relationship to the roots.

A comparison of Kodak Ultraspeed and Ektaspeed plus dental X-ray films for the detection of dental caries.

BACKGROUND: Using the fastest dental X-ray film available is an easy way of reducing exposure to ionizing radiation. However, the diagnostic ability of fast films for the detection of proximal surface caries must be demonstrated before these films will become universally accepted. METHODS: Extracted premolar and molar teeth were arranged to simulate a bitewing examination and radiographed using Ultraspeed and Ektaspeed Plus dental X-ray films. Three different exposure times were used for each film type. Six general dentists were used to determine the presence and depth of the decay in the proximal surfaces of the teeth radiographed. The actual extent of the decay in the teeth was determined by sectioning the teeth and examining them under a microscope. RESULTS: There was no significant difference between the two films for the mean correct diagnosis. However, there was a significant difference between the means for the three exposure times used for Ultraspeed film. The practitioners used were not consistent in their ability to make a correct diagnosis, or for the film for which they got the highest correct diagnosis. CONCLUSIONS: Ektaspeed Plus dental X-ray film is just as reliable as Ultraspeed dental X-ray film for the detection of proximal surface decay. The effect of underexposure was significant for Ultraspeed, but not for Ektaspeed Plus. Patient exposure can be reduced significantly with no loss of diagnostic ability by changing from Ultraspeed X-ray film to Ektaspeed Plus X-ray film.

Dipeptidyl-peptidase II and cathepsin B activities in amelogenesis of the rat incisor.

A body of published evidence suggests that a significant portion of enamel matrix protein synthesized by ameloblasts localises in the lysosomal-endosomal organelles of these enamel organ cells. Little is known regarding the lysosomal proteolytic activities during amelogenesis. The aims of this study were to detect and measure the activities of lysosomal peptidases cathepsin B (E.C. 3.4.22.1) and dipeptidyl-peptidase II (E.C. 3.4.14.2) in the enamel organ of the rat incisor and to ascertain whether rat enamel matrix proteins are degraded by these peptidases in vitro. Whole enamel organs were dissected from rat mandibular incisors. Enamel protein was also collected from the rat teeth. Analysis indicated that the rat incisor enamel organs contained specific activities of both dipeptidyl-peptidase II and cathepsin B at levels comparable with those of kidney which is rich in both these lysosomal peptidases. Gel electrophoresis and immunoblotting demonstrated that both cathepsin B and dipeptidyl-peptidase II were able to substantially degrade the rat enamel proteins in vitro. Based on these observations, we propose that lysosomal proteases have roles in amelogenesis in the intracellular degradation of amelogenins.

A comparison of Kodak Ultraspeed and Ektaspeed Plus dental X-ray films for use in endodontics.

BACKGROUND: The advantage of using a faster film for length determination in endodontic therapy is obvious. However, for such a film to be generally accepted, it must demonstrate comparable diagnostic quality to traditionally used films. METHODS: The comparative accuracy of canal length determination of Ultraspeed and Ektaspeed Plus dental X-ray films was assessed in maxillary first and second molars; for different canals, for different teeth, for different exposures, and for different examiners (five general dentists and three endodontic specialists). RESULTS: In general, there were no significant differences between films, among examiners, or any interaction between films and exposures. That is, an assessor's ability to estimate lengths was not significantly influenced by the film type or by exposure used. There was a wide divergence in the individual assessor's ability to estimate lengths. Specialists estimated lengths more accurately than general practitioners and estimated lengths more accurately with Ektaspeed Plus film. Length determination in distobuccal and mesiobuccal canals was more accurate than in palatal canals. Most palatal canals were underestimated in length by more than 1mm. The use of file sizes larger in number than size 15 is recommended in these canals. CONCLUSION: For length determination, Ektaspeed Plus dental X-ray film is as effective as Ultraspeed film. Given the acceptable quality and accuracy of Ektaspeed Plus film, there seems to be no clinical reason to subject patients to greater radiation by using a slower film during endodontic therapy.

Getting the most from rotational panoramic radiographs.

Rotational panoramic radiographs have become an invaluable tool in modern dentistry. To use the full potential of this resource the entire radiograph must be examined in a systematic way to extract the great wealth of information available. This paper provides the framework for the development of a systematic method to examine panoramic radiographs. The essential elements are that all areas of the radiograph should be examined and that there are a number of high yield areas with regard to pathology that require special attention.

The glandular odontogenic jaw cyst: report of a case.

A case of a rare odontogenic cyst arising in the lateral periodontal membrane in the mandible in a 14 year old girl is reported. This lesion appeared to be a new entity and has been named glandular odontogenic cyst (GOC) or sialo-odontogenic cyst. Histologically the lesion was lined by mucous producing cuboidal epithelium containing several areas of thickening and numerous duct-like structures. The cyst recurred with the same histology two years postoperatively.

Local control following therapeutic nodal dissection for melanoma.

Regional recurrence of melanoma is usually treated with surgical resection alone. Unfortunately sites of failure following surgical resection are poorly documented. Little information exists regarding local failure following surgery. In order to define local control, a retrospective analysis was performed of all patients undergoing a potentially curative lymph node dissection for metastatic melanoma. From 1978 to 1988, 48 patients underwent lymph node dissection with removal of all known disease (15 axillary, 25 groin and 8 radical neck dissections). Seven patients had stage II disease with simultaneous resection of the primary lesion and nodal dissection. The remaining 41 patients had stage I disease with dissection delayed until nodal metastasis became apparent. Of these 48 patients, 25 experienced local failure for an overall local control rate of 48%. Univariate and multivariate analysis showed only age to be a statistically significant prognostic indicator of local failure with a rate of 31% for patients < 50 years of age vs. 66% for patients > 50 years of age (P = 0.02). Nodal size, number of nodes involved, extracapsular extension, initial stage, location, or sex did not influence prognosis. Although not statistically significant, time to recurrence was much shorter in patients with extracapsular extension, 5 months vs. 16 months. With an overall local failure rate of 52% following a potentially curable therapeutic nodal dissection further local treatment should be considered.

Radiosurgery for acoustic neuroma.

Radiosurgery has been used for many years with great success for the treatment of acoustic neuroma. We present three cases in Louisiana using the E L Fisher system, the results of treatment, and a discussion of acoustic neuroma.

Cytochemical localization of dipeptidyl peptidase II activity in rat incisor tooth ameloblasts.

Dipeptidyl peptidase II (DPP II), E.C. 3.4.14.2, a serine class endopeptidase, is widely used as a lysosomal marker in cytochemical studies. To date most ultrastructural studies of ameloblasts use the presence of acid phosphatase activity to identify cellular organelles to be lysosomal. Using decalcified rat mandibles, with kidney tissue as a positive control, DPP II activity, was assessed with specific substrate Lysyl-alanine-4-methoxy-2-naphthylamide in ameloblasts at an ultrastructural level. Reaction product (RP) indicative of DPP II activity was observed only within lysosome-like organelles. These RP-labelled organelles were only localized in the supra- or para-nuclear regions of the ameloblasts, which corresponds with previous studies using acid phosphatase cytochemistry. However, in contrast with these studies, RP was not detected in the distal region of the ameloblasts, viz., in the Tomes' processes of the secretory ameloblasts or near the ruffled border in the maturation ameloblasts. The transitional ameloblasts were notable for the intensity of staining of their RP-labelled organelles. We propose that DPP II may have a role in programmed cell death which is thought to occur in this transition zone. Biochemical analysis of rat incisor enamel organ homogenates, indicated tissue fixation resulted in an 82% reduction in DPP II activity, although the specific activity of DPP II was not affected.

The effect of chronic fluoride administration on rat condylar cartilage.

Morphometrical and histochemical techniques were used to demonstrate changes to the cartilage layer of the rat temporomandibular joint condyle following chronic exposure to fluoride. An increase in thickness of the cartilage layer was noted in rats given 100 parts per million sodium fluoride in drinking water. No significant changes were observed with either control or low dose (10 parts per million) groups. The observed thickening was attributable to an increase in number and size of cells of the lower hypertrophic zone. Accumulations of glycogen were observed in these cells, which reflects the inhibitory effect of fluoride on glycolysis. Stimulation of chondrocytes by fluoride may have delayed the normal processes of capillary invasion, resulting in thickening of the cartilage layer. No changes to staining patterns of immature or mature types of collagen were observed, nor did the staining pattern of detectable glycosaminoglycans change due to fluoride.