Keratocystic odontogenic tumour: systematic review.

OBJECTIVES: The aim of this review is to evaluate the principal clinical and conventional radiographic features of non-syndromic keratocystic odontogenic tumour (KCOT) by systematic review (SR), and to compare the frequencies between four global groups. METHODS: The databases searched were the PubMed interface of Medline and LILACS. Only those reports of KCOTs that occurred in a series of consecutive cases, in the reporting authors' caseload, were considered. RESULTS: 51 reports, of 49 series of cases, were included in the SR. 11 SR-included series were in languages other than English. KCOTs affected males more frequently and were three times more prevalent in the mandible. Although the mean age at first presentation was 37 years, the largest proportion of cases first presented in the third decade. The main symptom was swelling. Over a third were found incidentally. Nearly two-thirds displayed buccolingual expansion. Over a quarter of cases recurred. Only a quarter of all SR-included reported series of cases included details of at least one radiological feature. The East Asian global group presented significantly as well-defined, even corticated, multilocular radiolucencies with buccolingual expansion. The KCOTs affecting the Western global group significantly displayed an association with unerupted teeth. CONCLUSIONS: Long-term follow-up of large series that would have revealed detailed radiographic description and long-term outcomes of non-syndromic KCOT was lacking.

Orthokeratinized odontogenic cyst: a systematic review.

OBJECTIVES: The aims of the review were to evaluate the principal clinical and conventional radiographic features of orthokeratinized odontogenic cyst (OOC) by systematic review (SR), and to compare the frequency of OOC between four global groups. METHODS: The databases searched were the PubMed interface of MEDLINE and LILACS. Only those reports of OOCs that occurred in a consecutive series of OOCs in the reporting authors' caseload were considered. RESULTS: 37 reports on 36 case series were included in the SR. OOC affected males twice as frequently and the mandible almost 2.5 times as frequently. Although the mean age at first presentation was 35 years, the largest proportion of cases first presented in the third decade for the Western, East Asian and Latin American global groups. Seven reports included details of at least one clinical finding. 11 reported case series included at least 1 radiological feature. All OOCs were radiolucent, 93% were unilocular and 68% were associated with unerupted teeth. 28% of the reported case series included follow up. 4% of OCC recurred and all of these were in the Western global group. CONCLUSIONS: Although one feature of OOCs is that they are unlikely to recur, some do. Not only is there a lack of long-term follow up of large series with long-term outcomes of OOC, but there is a paucity of clinical and radiological details of OOC at initial presentation.

Orthokeratinized odontogenic cyst in a Hong Kong community: the clinical and radiological features.

OBJECTIVES: The aim was to evaluate the principal clinical and conventional radiological features of a consecutive series of cases of orthokeratinized odontogenic cyst (OOC) affecting a Hong Kong Chinese community and to determine the outcome by follow-up. METHODS: All cases were accompanied by appropriate radiography and were confirmed by histopathology. RESULTS: The clinical and conventional radiological presentations, differential diagnoses and outcomes of follow-up of five consecutive OOCs were reviewed. There were two males and three females. All affected the posterior sextant. The mean age at first presentation was 33.5 years. The mean of their period of prior awareness was 0.11 years. Swelling was the most frequent presenting symptom. All presented as well-defined corticated radiolucencies; three were unilocular and two were multilocular and all displayed expansion. This resulted in displacement and erosion of the lower border of the mandible in one case and the downward displacement past the lower border of a lateral cortex in two others. The inferior dental canal in each mandibular case exhibited both displacement and absence. The antrum was affected in a sole maxillary case. Four patients were followed up for a mean of 8.5 years. The fifth patient discharged himself shortly after surgery. No lesions recurred. CONCLUSIONS: OOCs in this community displayed an expansile character, but did not recur after moderately long follow-up. The time between the prior awareness of their disease and their presentation for diagnosis and treatment was, so far, the shortest for any lesion affecting the jaw in this Hong Kong Chinese community.

Glandular odontogenic cyst: systematic review.

OBJECTIVES: The aim of this study was to evaluate the principal features of "glandular odontogenic cyst" (GOC), by systematic review (SR), and to compare their frequencies among four global groups. METHODS: The databases searched were the PubMed interface of MEDLINE and LILACS. Only those reports of GOCs that occurred in a series in the reporting authors' caseload were considered. All cases were confirmed histopathologically. RESULTS: 18 reports on 17 series of consecutive cases were included in the SR. GOC affected males twice as frequently and the mandible almost three times as frequently. The mean age at first presentation was 44 years, coincident with that of the Western global group, in which the largest proportion of reports and cases first presented in the second half of the fifth decade. However, age at presentation of GOCs in the East Asian and sub-Saharan African global groups was nearly a decade younger, this was significant. Six reports included details of at least one clinical presentation. Eight reports included at least one conventional radiological feature. There were some significant differences between global groups. The Western global group had a particular predilection for the anterior sextants of both jaws. The sub-Saharan African group displayed buccolingual expansion (as did the Latin American group) and tooth displacement in every case. 18% of GOCs recurred overall, except in the sub-Saharan African global group. CONCLUSIONS: GOCs have a marked propensity to recur in most global groups. GOCs presented in older patients and with swellings, affected the anterior sextants of both jaws, and radiologically were more likely to present as a well-defined unilocular radiolucency with buccolingual expansion. Tooth displacement, root resorption and an association with unerupted teeth occurred in 50%, 30% and 11% of cases, respectively.

Keratocystic odontogenic tumour in a Hong Kong community: the clinical and radiological features.

OBJECTIVES: The aim of this study was to evaluate the clinical and conventional radiological features of a consecutive series of cases of "keratocystic odontogenic tumour" (KCOT) affecting a Hong Kong Chinese community and to determine their outcome by follow-up. METHODS: All cases were accompanied by appropriate radiography and were histopathologically confirmed. RESULTS: 33 consecutive KCOTs were reviewed. 18 patients were male. The mean age at first presentation was 30.6 years. Swelling was the most frequent presenting symptom. Those patients first presenting with pain were significantly older, whereas those first presenting with a maxillary lesion were significantly younger. The maxilla and mandible were affected in 13 and 20 cases, respectively. KCOTs were most frequently confined to the posterior sextants of both jaws. KCOTs affecting the maxilla were mainly unilocular, whereas those affecting the mandible were multilocular. Patients with multilocular KCOTs were significantly older. Patients with KCOTs associated with root resorption were significantly older, whereas patients associated with unerupted teeth were significantly younger. 69% displaced teeth, 41% resorbed them and 56% were associated with unerupted teeth. All but two were followed up for at least 2 years. Three lesions recurred. CONCLUSIONS: KCOTs in this community displayed some differences from those reported in the literature.

Ossifying fibroma: a systematic review.

OBJECTIVES: The aim was to evaluate the principal features of ossifying fibroma (OF) by systematic review (SR), and to compare their frequencies among four global groups. METHODS: The databases searched were the PubMed interface of MEDLINE and LILACS. Only those reports of OFs that occurred in a series in the reporting authors' caseload were considered. All cases were confirmed fibro-osseous lesions histopathologically. The SR-included series had also to have used radiographs. RESULTS: Of the 64 reports (including the Hong Kong report) considered, 32 reports and a total of 781 cases were included in the SR. Ten SR-included series were in languages other than English. OF affected females more frequently, but was three times more prevalent in the mandible. The mean age at first presentation was 31 years. The decade with the greatest frequency was the fourth. Females were in the majority except in the first decade. The main symptom in 66% of all SR-included cases was swelling (including deformation of the jaws). 31% were found incidentally. 84% of cases displayed buccolingual expansion; half of the mandibular cases exhibited downward displacement of the lower border of the mandible and 90% of maxillary cases involved the maxillary antrum. Only 28% of reports included follow-up; 12% of cases recurred or were reactivated. CONCLUSIONS: Although long-term follow-up of large series that would have revealed the long-term outcomes of OF was lacking, a 12% recurrence rate is clinically significant and suggests that OFs should be considered for long-term follow-up.

Ossifying fibroma in a Hong Kong community: the clinical and radiological features and outcomes of treatment.

OBJECTIVES: The aim of this study was to evaluate the principal clinical and radiological features of a consecutive series of cases of ossifying fibroma (OF) affecting a Hong Kong Chinese community and to determine their outcome by follow-up. METHODS: All cases were accompanied by appropriate radiography and were histopathologically confirmed as fibro-osseous lesions. RESULTS: The clinical and radiological presentations, differential diagnoses and outcomes of follow-up of 24 consecutive patients with OFs were reviewed. All patients were female. The mean age at first presentation was 38.0 years. The oldest reported patient first presenting with OF was 80 years old. Most OFs (58%) were discovered incidentally. The maxilla and mandible were affected in 4 and 20 cases, respectively. Only 7 cases, out of the 15 cases for which provisional diagnosis was available, included OF. 16 patients were followed up for a mean of 5.3 years, of whom 12 discharged themselves after a mean of 3.0 years. Only one lesion recurred. CONCLUSIONS: OF in this community predominantly affects females. Although gynaecological history was not included in the clinical notes, there is a clear possibility of reactivation of OF growth at the menopause. Other potentially important contributing factors are "traditional Chinese medicine" and the progressive reduction in the degree of water fluoridation. Although most patients were followed up, this was only for a few years. Nevertheless, one case actually recurred during follow-up. Therefore, patients with OF should be encouraged to maintain follow-up for a longer period.

Fibrous dysplasia in a Hong Kong community: the clinical and radiological features and outcomes of treatment.

OBJECTIVES: To evaluate the principal clinical and radiological features of a consecutive series of cases of fibrous dysplasia (FD) affecting a Hong Kong Chinese community and to determine their outcome by follow-up. METHODS: All cases were accompanied by appropriate radiography and were histopathologically confirmed as fibro-osseous lesions. RESULTS: The clinical and radiological presentations, differential diagnoses and outcomes of follow-up of 21 consecutive FD cases were reviewed. Females were slightly more frequently affected, but there was no gender predilection for either jaw. The mean age at first presentation was 25 years, which upon adjustment for prior awareness fell to 21 years. The main symptom was swelling (including enlargement of the jaw). The maxilla and mandible were affected in 9 and 13 cases, respectively; both jaws were affected in 1 case. One case was of McCune-Albright syndrome. The sole provisional diagnosis for all lesions was FD; most lesions affected all or almost half the affected jaw. 17 patients were followed-up for a mean of 9 years. CONCLUSIONS: This very detailed consecutive series followed up over many years, in which a number of cases recurred or were reactivated in adulthood, firmly dispells the notion that FD is a simple hamartoma in all cases. This community was quite amenable to really long-term follow-up.

Focal cemento-osseous dysplasia: a systematic review.

OBJECTIVES: To evaluate the principal features of focal cemento-osseous dysplasia (FocCOD) by systematic review (SR) and to compare their frequencies between four global groups. METHODS: Alternative names for FocCOD were used as search terms. The databases searched were the PubMed interface of Medline and LILACS (Literature Index for Latin-America and the Caribbean; Biblioteca Regional de Medicina (BIREME)). Only those reports of FocCODs which occurred in a series in the reporting authors' caseload were considered. All cases used radiographs and were confirmed fibro-osseous lesions histopathologically. RESULTS: Of the 20 series considered, 10 were included in the SR. Five SR-included series were of East Asian communities. 64% of all SR-included cases were found incidentally. FocCOD predominantly affects females and the mandible. The three predominant radiological presentations varied significantly between reports. CONCLUSIONS: The two at-risk global communities appear to be East Asians and those of black African origin. Although there appears to be little difference between East Asians and non-East Asians, the significant differences between them with regards to the predominant radiological presentation could suggest that either all communities vary in their presentation or that most, if not all, did not reflect the true frequency within their communities. Long-term follow-up of large series that would have revealed the long-term outcomes of FocCODs was lacking. This is necessary because of both FocCOD's predilection of edentulous areas, increasingly required for osseointegrated implants, and its wide differential diagnosis, which includes some lesions normally treated by surgery.

Ameloblastoma in the Hong Kong Chinese. Part 2: systematic review and radiological presentation.

OBJECTIVES: The aim of this part of the study was to determine the radiological presentation on conventional radiographs of central ameloblastomas in the Hong Kong Chinese and compare them with other reported series by a systematic review (SR). METHODS: The study had two elements, that of a complete series of all ameloblastomas presenting at a major Chinese maxillofacial surgical unit and a SR. The files of the Department of Oral and Maxillofacial Surgery of the University of Hong Kong between 1989 and 2000 were reviewed for ameloblastoma cases. The relevant literature was identified by electronic databases, review of citation lists and handsearching of key journals. The principal selection criterion was that the study should represent a complete collection of cases. RESULTS: Only 13 reports gave any radiological details. The present study of the Hong Kong Chinese contained 61 cases. With the exception of radiodensity and shape of radiolucency, the majority of the 13 other reports did not record the other radiological features that could be important in the diagnosis. The present study agreed with the synthesis of the 13 reports with regards to complete radiolucency and cortication of ameloblastomas, but disagreed with regards to other important features. The present study had a significantly higher proportion of unilocular lesions, better marginal definition, and more frequent perforation of the cortex and buccolingual expansion. Nine of the ten maxillary lesions straddled both anterior and posterior sextants with four crossing the midline, whereas only 13 of the 51 mandibular cases affected both sextants, of which eight crossed the midline. The unicystic form, which was most prevalent, appeared significantly more frequently as unilocular radiolucencies in comparison with the non-unicystic forms. The frequencies of unicystic forms and unilocular presentations were significantly greater in the young. The lesions in the young were significantly sited solely in the posterior sextant. The lower border of the mandible was reached and affected by ameloblastoma in 36 cases in the present report. It was displaced and thinned in 15 cases whereas in just five it was at least partially undisplaced with the lesion expanding down past it either buccally or lingually to it. The unicystic form was significantly more associated with root resorption, tooth displacement and crowns of unerupted teeth. CONCLUSIONS: Radiologically, ameloblastomas in the Hong Kong Chinese differ significantly with regards to many features. This can be in part explained by the higher proportion of the unicystic form.

Ameloblastoma in the Hong Kong Chinese. Part 1: systematic review and clinical presentation.

OBJECTIVES: The aim of Part 1 of this study was to determine the clinical presentation of central ameloblastomas in the Hong Kong Chinese and to compare them with other reported series by a systematic review (SR). METHODS: The study had two elements, that of a complete series of all ameloblastomas presenting at a major Chinese maxillofacial surgical unit as well as a SR. The files of the Department of Oral and Maxillofacial Surgery of the University of Hong Kong between 1989 and 2000 were reviewed for ameloblastoma cases. The relevant literature was identified by electronic databases, review of citation lists and hand searching of key journals. The principal selection criterion was that the study should represent a complete collection of cases. RESULTS: Fifty-three published series of cases were included in the SR. They generally reported little more than sex, mean age and range, and affected jaw. Only 16 studies considered recurrence. Sixty-one cases of ameloblastoma were identified in the present study. There were 30 males and 31 females, contrary to the predilection for males in other reports. Eighty-four percent of cases were found in the mandible, agreeing with the SR. The mean age at first presentation was 30.5 years, lower than that of the SR; only a Korean report and a small Bangladeshi report showed younger presentation. The present report had the shortest period between first becoming aware of the lesion and seeking treatment; this period was significantly shorter for younger patients. Although the present study was in agreement with the SR with regard to swelling, this study reported a significantly higher proportion of patients presenting with pain. CONCLUSION: Although the presentation of ameloblastoma within this Chinese community was broadly similar to that observed in other populations, it differed in a number of important respects. It had a younger age at first presentation than many other communities, including other Orientals; it was associated with a shorter period between first becoming aware of the lesion and seeking treatment, particularly in the young; and it was more frequently associated with pain than in the SR.

Computed tomography of fibrous dysplasia.

OBJECTIVE: Fibrous dysplasia (FD) is an uncommon, but important lesion affecting the jaws. The aim of this study was to reveal its presentation on computed tomography (CT) in a consecutive series of cases. METHODS: The files of the Department of Oral and Maxillofacial Surgery of Hong Kong University between 1989 and 2000 were reviewed for cases of FD. RESULTS: Of the ten cases investigated by CT, two were rejected because of extensive biopsy or surgery before the CT investigation. Seven of the remaining eight cases were Chinese and one was Indian. The mandible and maxilla were equally affected. The cortex was generally intact, except when adjacent to the teeth in the maxilla. The margins were generally poorly-defined, but well-defined on at least some sections of each maxillary case. Five cases were extensive, affecting or nearly affecting the whole hemi-mandible or hemi-maxilla to the midline. All cases displayed expansion, which was fusiform in the mandible and an enlargement of the normal contour in the maxilla. The maxillary antrum was completely obturated in three maxillary cases; one displayed a rounded dome-shaped lesion more suggestive of a benign neoplasm. The orbital floor was displaced in three cases; one of those cases presented with proptosis. All maxillary cases extended back to the pterygoid process, but did not displace it. The "bone windows" of eight cases generally displayed a "ground-glass" pattern; one also displayed cyst-like radiolucencies. The soft tissue window, which depicts mineralized tissue as "white", showed that five cases were completely mineralized. CONCLUSION: CT can be used to determine the extent, specific dimensions and radiodensity of FD.

Computed tomography of odontogenic myxoma.

AIM: The aim of this study was to determine the computed tomography (CT) presentation of odontogenic myxoma (OM) in a Chinese population and to compare them with those observed on the accompanying conventional radiographs (CR). MATERIALS AND METHODS: The files of the Department of Oral and Maxillofacial Surgery of the University of Hong Kong between 1989 and 2000 were reviewed for myxoma cases. RESULTS: Ten cases of OM were found of which eight had been investigated by CT. The formatted hard copy was found in seven cases, four in the maxilla and three in the mandible. Most of the OMs had a round shape but one was fusiform. CT was more likely to display a cortex and its perforation. All OMs had perforated cortices on CT with soft tissue appearing outside the bony contour in two cases. Contrast enhancement was apparent in six cases. Both CR and CT displayed septae, but the latter method revealed that most septae were situated at the periphery, presenting as "sunray" type spicules in one case. Tooth displacement and root resorption were more reliably observed on CR. CONCLUSION: The likelihood of perforation and pattern of septa of OM is better displayed by CT. CR should also allow a better assessment of the degree of definition of the lesion's margins with adjacent normal bone. Therefore, both CT and CR should be used in an investigation of an OM.

Fibro-osseous lesions of the face and jaws.

Maxillofacial fibro-osseous lesions (FOL) consists of lesions that differ, with the exception of fibrous dysplasia, to those found in the rest of the skeleton. FOLs of the face and jaws are cemento-osseous [corrected] dysplasia, fibrous dysplasia and cemento-ossifying fibroma. Radiology is central to their diagnosis because the pathology for all FOLs is similar, although they range widely in behaviour, from dysplasia, hamartoma to benign neoplasia with occasional recurrence. Furthermore, once diagnosed the management of each is different. For cemento-ossifying dysplasia, this may mean doing nothing, simply because no treatment is generally appropriate. Almost all cemento-osseous [corrected] fibromas should be treated surgically, whereas cases of fibrous dysplasia are treated according to their clinical presentation, ranging from review and follow-up to surgery necessary to save the patient's sight or reduce deformity. The most important and frequent features of the FOLs differential diagnosis is discussed with assistance of a flow-chart.

Florid cemento-osseous dysplasia: a systematic review.

OBJECTIVES: To evaluate the principal features of florid cemento-osseous dysplasia (FCOD) by systematic review (SR), with particular regard to comparison of Oriental with non-Oriental populations, and of reports derived from pathology files with those from non-pathology sources. METHODS: All alternative names for FCOD were used as search terms for two electronic databases, namely Medline and "Web of Science". Only multiple forms of cemento-osseous dysplasia occurring in a series in the reporting authors' case load were considered. RESULTS: Medline produced more SR-identified reports. The search terms "Cementoma" and "Osseous Dysplasia" were the most effective for both databases. One hundred and fifty-eight cases of FCOD were observed in 17 series of patients reported in 16 SR-identified reports. Fifty-nine percent of cases were found in Blacks, 37% in Orientals and 3% in Caucasians. Ninety-seven percent were females. Fifty percent of cases in the SRs were observed incidentally. Pain was most frequent in those with presenting symptoms, and was significantly more frequent in the Oriental series. In two studies on the same Chinese community, those cases found incidentally on radiographs alone were significantly younger than those with symptoms in the pathology files. CONCLUSION: The nomenclature for FCOD is extensive, but older and more general terms were more effective in recalling SR-identified reports. Cases in a report based on pathology files appear to be older than those in a report based on radiology alone files. With the exception of a higher prevalence of pain in Orientals, mainly Chinese, there did not appear to be any differences in presentation compared with that observed in Black communities.

Odontogenic myxomas in the Hong Kong Chinese: clinico-radiological presentation and systematic review.

AIM: The aim of this study was to determine the clinical and radiological presentation on plain films of central odontogenic myxomas (OM) in the Hong Kong Chinese and compare them to other reported series by a systematic review (SR). METHODS: The study had two elements, that of a complete series of all OMs presenting at a major Chinese maxillofacial surgical unit and a SR. The files of the Department of Oral and Maxillofacial Surgery of the University of Hong Kong between 1989 and 2000 were reviewed for OM cases. The relevant literature was identified by electronic databases, review of citation lists and handsearching of key journals. The principal selection criterion was that the study should represent a complete collection of cases. RESULTS: The SR revealed that only a quarter of the reports provided any quantitative radiological details. Just under half of the included reports provided the relative period prevalence of OMs compared to other odontogenic tumours, but these reports almost completely excluded consideration not only of the radiology but also specific clinical details. Furthermore, they did not report of recurrence data, an important feature of the OM. Most of the most recent reports were concerned with relative period prevalence. The relative period prevalence and 'number of OMs per hospital per year' of studies separated by two or more decades in Hong Kong and Nigeria indicate an increase in the number of lesions diagnosed as OMs. The 10 Hong Kong cases were broadly consistent with the predilections for females and the mandible of other reports. The mean age at first presentation in the present report is 36.9, older than the other reports. Most lesions are large, affecting both posterior and anterior quadrants. They appear to be larger than those in many other reports. Two of the OMs are accompanied by histories of recent rapid growth. Tooth displacement and root resorption are more frequently observed in OMs in the present study. Although all OMs in the present study are still being followed up after surgery, none have recurred. CONCLUSION: Although the presentation of larger lesions in the older Chinese could in part be explained by attitudes rooted in traditional medicine in spite of the widespread availability of modern medical care in Hong Kong, there is a history of recent rapid growth in at least two cases. An emphasis by recent reports on the OMs' relative period prevalence of concurrent odontogenic lesions, has omitted recording the radiology and the specific clinical details usually required for diagnosis.,

Systematic review in diagnostic radiology.

Systematic review (SR) already makes a major contribution to evidence-based healthcare by making the review process transparent and by reducing bias. SR has been successfully applied to observational studies. Radiologists have already begun to make an impact in dentistry by using SR as a decision-making tool. Central to SR is establishment of a research question, selection criteria, a search plan, a literature search, an appraisal of the identified literature by the selection criteria; an analysis and a formulation of recommendations. With regard to the literature search, electronic databases (Medline, Embase, Science Citation Index, Lilacs), controlled subject headings, exploding and free-text searching, handsearching and the gray literature are discussed.

Calcification of the stylohyoid complex in Londoners and Hong Kong Chinese.

AIM: To compare the prevalence and pattern of calcification of the stylohyoid complex in Hong Kong Chinese with that in London. METHODS: The panoramic radiographs of two consecutive series of patients attending the primary dental care departments were reviewed, 862 patients in Hong Kong and 800 in London. The morphology of the stylohyoid complex was allocated to one of 12 patterns. RESULTS: A normal styloid process is significantly more prevalent in Hong Kong (P<0.01). A calcified stylohyoid ligament is significantly more common in London (15.8%) than Hong Kong (3.9%, P<0.01), whereas there is no difference in the prevalence of an elongated styloid process (7.8% in London and 8.6% in Hong Kong). Segmentation was significantly more prevalent in London (P<0.01), whereas symmetry predominated in Hong Kong (P<0.01). Although the mean age of the Hong Kong patients was significantly older than those in London (P<0.001), those with a calcified stylohyoid ligament tended only to be older (0.025>P>0.01). There was no significant difference in age for an elongated styloid process. CONCLUSION: There are significant differences in the morphology of the stylohyoid complex between London and Hong Kong. A calcified stylohyoid ligament is more prevalent in Londoners.

The contribution by medical radiology departments to dental radiology in general dental practice in Scotland.

AIM: To determine the availability of the services of medical radiology departments to general dental practitioners in Scotland. METHODS: Fifty-seven hospitals were identified as likely to have services available to general dental practitioners; 41 were within central urbanised areas (the 'Central Belt') and 16 in the more remote rural areas, (the 'Borders, Highlands and Islands'). The available services were identified by questionnaire. RESULTS: All 57 questionnaires were returned. Although there were significantly fewer larger hospitals in the 'Borders, Highlands and Islands', there was no significant difference in availability of services to general dental practitioners between the two parts of Scotland. CONCLUSION: The services of medical radiology departments are generally available to general dental practitioners in both the 'Central Belt' and the 'Borders, Highlands and Islands'.

Idiopathic osteosclerosis in the jaws of Britons and of the Hong Kong Chinese: radiology and systematic review.

AIM: To compare the prevalence of idiopathic osteosclerosis in the jaws in Hong Kong and Britain. METHODS: The panoramic radiographs of consecutive patients who attended the primary care departments of the dental hospitals in Hong Kong in 1981 and 1990 and London in 1990 and of Edinburgh in 1993 were reviewed. The size of the Hong Kong lesions was measured. The literature was subjected to systematic review. RESULTS: The prevalence of idiopathic osteosclerosis in Hong Kong in 1981 and 1990, London and Edinburgh was 6.7, 5.5, 2.7 and 4.1% respectively. The prevalence of idiopathic osteosclerosis was greater in the Oriental (Chinese and Japanese) than in Western surveys. The lesions in the 1990 Hong Kong survey in the third decade were significantly smaller than those in the 1981 survey. The decrease in size in Hong Kong 1990 was also accompanied by a reduction in overall prevalence. The predilection for the mandible, especially in the premolar area, was observed in the Chinese and London series; this feature was also common to all other reports. CONCLUSION: The Chinese have a greater prevalence of idiopathic osteosclerosis than Western populations.