Validation of a model to evaluate the role of radiographs in the diagnosis and treatment planning of periodontal diseases.

OBJECTIVES: The purposes of this study were (i) to see if an indirect method of design (paper patients) could be developed for study of change affected by radiographs on diagnostic outcome and planned treatment of periodontal patients and (ii) to investigate the effect of the nature of clinical examination on the value of radiographs in reaching a periodontal diagnosis. Paper cases could allow the design of examiner blind studies where repeatability could be assessed. METHODS: 201 patients were assigned to one of four groups and clinically assessed according to group specifications. Radiographs were taken. Periodontal diagnoses and treatment plans were drawn up for each patient with and without radiographic information (real patient). Simulated paper transcriptions were made for each subject and diagnoses and treatment plans were again drawn up (paper patient). RESULTS: For many diagnoses and treatment options assessments were similar for real and paper patients. There was substantial agreement between periodontal diagnoses reached from real and paper assessments (kappa=0.68). Greater differences were seen for extractions and periodontal surgery. Paper assessments better replicated real assessments when more thorough clinical examinations were undertaken. The relatively time efficient Group 2 clinical assessment appeared to perform similarly to the extensive Group 4 clinical assessment. CONCLUSIONS: The model described may be useful for simulating real patients for studies of this nature. The Group 2 assessment appeared to give sufficient clinical information for patient management and may be an appropriate choice for initial diagnosis and treatment planning of periodontal patients.

The effectiveness of undergraduate teaching of the identification of radiographic film faults.

OBJECTIVES: To see if there were any differences in the ability of final year dental students at two UK dental schools, who were within 4 months of graduation, to identify radiographic film faults. METHODS: The two groups of undergraduates were shown 11 dental radiographs using a slide format. The 11 radiographs included 8 films with film faults, 2 films without technical or processing errors and a film with minimal faults. Each student was asked to assess each film for the presence/absence of film fault(s), to detail how to correct the fault (if appropriate) and to give a subjective quality rating of each film. RESULTS: The range of marks obtained by both groups of students was low. All students found the identification of panoramic film faults more challenging than faults associated with intraoral films. 15% of students from University B scored more than half the possible marks compared with 2% from University A. CONCLUSIONS: Both groups of students had the necessary knowledge of how to correct faults once identified. However, the marked difference in competency in identifying faults between the two groups of students has implications for the future teaching and development of the radiology curriculum.

Use of the basic periodontal examination and radiographs in the assessment of periodontal diseases in general dental practice.

OBJECTIVES: The aims of this study were to investigate (1) the use of the basic periodontal examination (BPE) by general dental practitioners (GDPs) and their selection of radiographs for the assessment of periodontal disease and (2) whether this selection concurred with existing selection (referral) criteria. METHODS: Three mailings of a self-completion questionnaire were sent to 800 GDPs working in the National Health General Dental Service in England and Wales. Dentists were presented with six clinical scenarios for which they were asked to describe their use of radiographs. RESULTS: Ninety-one percent of dentists reported that they used the BPE in new patients, with 56% using it for all patients; 84% of dentists used BPE in recall patients. BPE use was related to the dentists' age and postgraduate qualifications. There was a wide variation in the radiographic views used for periodontal disease assessment. The choice of radiographs was not generally in line with the Faculty of General Dental Practitioners (UK) 1998 selection criteria, particularly for the clinical scenarios of pocketing >5 mm, irregular pocketing or pockets associated with teeth with heavy restorations. Sixty seven percent of dentists concurred with recommendations for radiographs for a suspected periodontal-endodontic lesion. CONCLUSIONS: A majority of dentists reported clinical screening for periodontal diseases using the BPE. There was considerable variation in the selection and use of radiographs and practice was not in line with existing guidelines for many clinical situations. Evidence-based referral criteria should be actively promoted to ensure high standards of radiographic practice in general dental practice.

Radiographic equipment and techniques used in general dental practice: a survey of general dental practitioners in England and Wales.

OBJECTIVES: The aims of this study were to determine the self-reported use of panoramic radiography, D- and E-speed film, rectangular collimation, film holders, equipment fitted with a long spacer cone (>200 mm) and the bisecting angle and paralleling techniques by general dental practitioners and to see if use was related to the dentists' age and postgraduate qualifications. METHODS: Three mailings of a self-completion questionnaire were circulated to 800 general dental practitioners working in the National Health General Dental Service in England and Wales. RESULTS: A response rate of 74% was achieved. Sixty-one percent of general dental practitioners reported use of panoramic equipment. Fifty percent of dentists always used E-speed film and 18% always used rectangular collimation. Sixty-eight percent of dentists always used bitewing film holders though fewer (37%) used periapical film holders. Sixty-three percent of dentists always used a long cone. The bisecting angle technique was used by 70% of dentists with 22% always using this technique for periapical radiographs. Thirty-one percent always used the paralleling technique. Use of panoramic equipment, periapical film holders, bisecting angle and paralleling techniques were associated with the dentists' age. Use of periapical film holders, bisecting angle and paralleling techniques and rectangular collimation were associated with dentists' postgraduate qualifications. CONCLUSIONS: There are several features of radiographic equipment and techniques that can aid high quality imaging and reduce patient dose. Although a number of these are being used in general dental practice in England and Wales they have yet to achieve universal adoption.

Survey of radiographic practices for periodontal disease in UK and Irish dental teaching hospitals.

OBJECTIVES: To assess current radiographic practices in dental teaching hospitals for the management of patients with periodontal diseases. METHODS: All 17 dental teaching hospitals in UK and Ireland were sent a questionnaire on radiographic equipment and radiograph selection currently used for assessment of patients with destructive periodontal diseases. Opinions were recorded for advantages and disadvantages of the most frequently used radiographic views. RESULTS: A 100% response rate was achieved. All hospitals used panoramic and specific periapical radiographs as one of their radiographic regimes for patients with periodontal disease. Fifty-three per cent of respondents most frequently took panoramic and selected periapical radiographs. Twenty-four per cent took full mouth periapical radiographs (FMPAs) most frequently and 18% took a panoramic radiograph alone. Twenty-four per cent of hospitals operated a protocol for selection of radiographs for periodontal patients. CONCLUSIONS: The most commonly used views taken to assess periodontal status are panoramic radiographs with selected periapicals. Few hospitals operate a protocol for prescribing radiographs.

Conservation of the deleted-in-azoospermia-like-1 (DAZL1) gene structure in old world monkeys points to a homologous function of DAZL1 in this primate class.

We isolated the complete deleted-in-azoospermia-like-1 (DAZL1) gene of the old world monkey Macaca fascicularis (tentatively designated as MafaDAZL1) and compared its sequence structure to that of the other DAZL1 genes isolated so far. In addition to the homologous RNA recognition motif (RRM domain), we only identified a high conservation of the Mafa-DAZL1 coding region to the mammalian DAZL1 genes (i.e. mouse: Dazl1; and human: DAZL1) and to that of Xenopus (xdazl). Only in the primates, Macaca fascicularis and human, sequences and lengths of the 5' and 3' untranslated DAZL1 gene structures (UTRs) displayed a similar conservation as their coding regions (i.e. 91-94%). Both belong to the primate class of old world monkeys evolutionarily separated 36-55 million years ago (1). The strong conservation of the complete DAZL1 gene structure in both primate species suggests a similar control and maturation pathway of DAZL1 transcripts in the germ line of old world monkeys and also indicates a homologous function of the DAZL1 RNA-binding protein in this primate class.

Two long homologous retroviral sequence blocks in proximal Yq11 cause AZFa microdeletions as a result of intrachromosomal recombination events.

We mapped the breakpoints of the AZoospermia factor a (AZFa) microdeletion located in proximal Yq11 in six men with complete germ cell aplasia, i.e. Sertoli Cell Only syndrome (SCO). The proximal breakpoints were identified in a long retroviral sequence block (HERV15yq1: 9747 nucleotides) at the 5' end of the DYS11 DNA locus in Yq11, interval D3. The distal breakpoints were found in a homologous HERV15 sequence block mapped to the Yq11 interval D6, i.e. in the distal part of the AZFa region (HERV15yq2: 9969 nucleotides). Compared with the HERV15yq1 sequence, HERV15yq2 is marked by a deletion of a HERV15 sequence domain at its 5' end and insertion of an LINE 1 3'-UTR sequence block (L1PA4) of similar length at its 3' end. The deletion of the L1PA4 element was recognized as the molecular origin of the DYS11 12f2 restriction fragment length polymorphism. For all six AZFa patients it was possible to perform PCR experiments bridging both retroviral sequence blocks, which map in a distance of 781.557 kb in proximal Yq11 in fertile men. The AZFa breakpoint-fusion regions were located in their recombined HERV15yq1/HERV15yq2 sequence blocks in either one of two long identical sequence domains (ID1 and ID2). We therefore assume that intrachromosomal recombination events between the two homologous retroviral sequence blocks in proximal Yq11 are probably the causative agents for most of the AZFa microdeletions observed in men with SCO syndrome. A mean value of 792 kb was estimated for their molecular lengths.

The usefulness of radiographs in diagnosis and management of periodontal diseases: a review.

OBJECTIVES: To review the periodontally significant diagnostic information obtainable from radiographs and the stages during periodontal therapy when the information may influence patient management and treatment outcomes. DATA: Confined to studies involving conventional radiography, as this remains the commonest imaging method in clinical dental practice and primary dental care setting. SOURCES: Literature was reviewed using Medline and manual tracing of references cited in key papers not otherwise elicited. STUDY SELECTION: Studies were selected in order to (i) define the role of radiographs in periodontal diagnosis and management at the initial, corrective and supportive (maintenance) phases of periodontal therapy and (ii) critically review the evidence for the value added by radiographs. CONCLUSIONS: Radiographs provide diagnostic information on alveolar bone levels, plaque retention factors, caries, furcation defects, subgingival calculus and additional pathology. Features visualised are dependent on the radiographic view. A relationship exists between probing attachment loss and radiographic bone height, with a range in level of correlation; clinical attachment may correspond more closely to surgical measurements of bone height. Radiographs can be used in planning initial, corrective and supportive phases of therapy, though some decisions may be made on clinical assessments alone. Evidence in the literature on benefit gained from radiographs taken for periodontal patients is sparse; the extent to which they influence the treatment provided and treatment outcomes is poorly addressed. Further research is indicated to define the role of radiographs when managing the periodontal patient to maximise the potential gain for the patient.

A comparison of the diagnostic utility of two image receptors for panoramic radiography.

OBJECTIVE: To compare the diagnostic utility of two screen-film systems for panoramic radiography, one based on green and the other on ultraviolet light. MATERIALS AND METHODS: Two hundred consecutive adult patients with teeth in all four quadrants requiring panoramic radiographs were randomly allocated to one of two groups. One group was imaged with OGA L (CEA AB, Strängnäs, Sweden) film using Lanex Regular (Eastman Kodak, Rochester, NY, USA) screens (the Lanex group). The other group was imaged using Ultra-Vision (Dupont UK Limited, Hertfordshire, UK) film and screens (the Ultra-vision group). Two different panoramic machines were used, a Planmeca (Planmeca OY, Helsinki, Finland) and Cranex (Soredex Orion Corporation, Helsinki, Finland). The radiographs were evaluated by two radiographers for overall quality and any faults recorded. Two dental radiologists evaluated the crestal and apical areas of every standing tooth on a 4-point scale. The likelihood of getting a high-quality image with the different films was modelled using logistic regression, adjusting for the radiologist and the area of the tooth being examined. Inter- and intra-examiner agreement was calculated using Kappa and weighted Kappa where appropriate. RESULTS: The radiographers recorded no significant differences in positioning errors between the two groups of film. However, the films produced on the Cranex were less likely to be recorded as excellent. The radiologists' interexaminer agreement for the lower molars and upper incisors was only moderate at best (kappa = 0.56). No significant differences were found between the likelihood of the two types of film providing a high-quality image. Crestal areas were more likely to be scored well than apical areas. CONCLUSION: There were no differences in ease of discerning apical and crestal areas between the two screen-film systems. There was only poor to moderate agreement between the two radiologists. Ultra-Vision can be recommended as an alternative to existing rare earth systems for panoramic radiography.

Arylsulfatase D gene in Xp22.3 encodes two protein isoforms.

The human genome contains six arylsulfatase genes (ARSA-ARSF), of which four are clustered in a distal region of the short arm of the X chromosome (Xp22.3). They were probably generated by a series of evolutionary duplication events; their exon-intron boundaries are identical. Nevertheless, different transcript lengths and the absence of cross-hybridizations point to a specific function of each gene in human cell metabolism, and multiple transcripts suggest the coding of protein isoforms. We identified a novel protein isoform of the ARSD gene by isolation of a series of cDNA clones from a human testis cDNA library. The clones were only partially identical to another series of ARSD clones isolated earlier (now designated ARSDalpha clones). Their specific C-terminal region (1160 nt) encodes a novel ARSD peptide of 48 amino acids and was identified as part of intron 6 of the ARSD gene in Xp22.3. We therefore designate them ARSDbeta clones. Expression analyses of ARSDalpha and ARSDbeta by semiquantitative RT-PCR revealed the presence of both in multiple human tissues, although in different quantities. A physiologic substrate for arylsulfatase D proteins is not known. We therefore estimated their sulfatase activities in vitro with the aid of the 4-methylumbelliferyl sulfate (4-MUS) assay. Surprisingly, neither ARSD protein isoform demonstrated any sulfatase activity alone or in combination, although their catalytic peptide domain is strongly conserved in comparison with that of the other X-chromosomal arylsulfatase enzymes (ARSC, ARSE, ARSF), all of which are functionally active in the 4-MUS assay.

Transfer of radiographs.

Dental radiographs constitute 25% of all exposures made in the UK and therefore in terms of radiation protection the population risk is not insignificant. Paragraph 11 of The Core of Knowledge in the Schedule to the Protection of persons undergoing medical examination or treatment (POPUMET) regulations specifies the importance of using existing radiological information, whether films or reports, about a patient. The Guidance Notes recommends that in order to reduce unnecessary radiographic examinations, there should be ready availability of previous radiographs. Access to previous radiographs is also commended by the National Radiological Practice Board (NRPB) and the Royal College of Radiologists (PCR) in their report on Patient Dose Reduction in Diagnostic Radiology. In addition to dose limitation, patient care is improved.

Evaluation of X-ray beam angulation for successful twin canal identification in mandibular incisors.

This study was undertaken to determine the most effective horizontal beam angulation for the diagnosis of twin canals in mandibular incisors. Two hundred extracted mandibular incisor teeth, in groups of four, were aligned in the form of a lower dental arch and radiographed using a beam alignment device at 10 degrees intervals between 0 degree and 50 degrees from both right and left sides. Five observers with varying degrees of experience were asked to assess the number of canals in each of the four teeth from these radiographs. A further radiograph of each individual tooth was taken at 90 degrees through the mesio-distal plane to identify the number of twin canals present. A random sample of 10% of the radiographs were viewed for a second time 3 months later to assess intra-observer variation. The 20 degrees right and 30 degrees left horizontal beam angulations showed significantly more accurate diagnosis of twin canals than the ortho-radial view (0 degree) by all five observers. Analysis of the inter-observer results suggests that the experienced viewers were no better but more consistent at identifying twin canals in mandibular incisors.

A SPGY copy homologous to the mouse gene Dazla and the Drosophila gene boule is autosomal and expressed only in the human male gonad.

We have isolated a series of human testis poly(A) cDNA clones by cross-hybridization to SPGY1, a Y gene homologous to DAZ. Their sequence analysis revealed an identical nucleotide composition in different 'full-length' clones, suggesting that all were encoded by the same gene. We mapped this gene to the short arm of chromosome 3 and designated it SPGYLA (SPGY like autosomal). Comparison of the SPGYLA cDNA sequence with the cDNA sequences of DAZ and SPGY1 revealed two prominent differences. The tandem repetitive structure of 72 bp sequence units (DAZ repeats) is absent. SPGYLA contains only one 72 bp sequence unit. Downstream of it, a specific 130 bp sequence domain is present which is absent in DAZ and SPGY1 but present in the mouse gene Dazla and in the Drosophila gene boule. SPGYLA encodes an RNA binding protein expressed only in the human male gonad. The data presented give strong evidence that not DAZ but SPGYLA is the functional human homologue of Dazla and boule.

Human Y chromosome azoospermia factors (AZF) mapped to different subregions in Yq11.

In a large collaborative screening project, 370 men with idiopathic azoospermia or severe oligozoospermia were analysed for deletions of 76 DNA loci in Yq11. In 12 individuals, we observed de novo microdeletions involving several DNA loci, while an additional patient had an inherited deletion. They were mapped to three different subregions in Yq11. One subregion coincides to the AZF region defined recently in distal Yq11. The second and third subregion were mapped proximal to it, in proximal and middle Yq11, respectively. The different deletions observed were not overlapping but the extension of the deleted Y DNA in each subregion was similar in each patient analysed. In testis tissue sections, disruption of spermatogenesis was shown to be at the same phase when the microdeletion occurred in the same Yq11 subregion but at a different phase when the microdeletion occurred in a different Yq11 subregion. Therefore, we propose the presence of not one but three spermatogenesis loci in Yq11 and that each locus is active during a different phase of male germ cell development. As the most severe phenotype after deletion of each locus is azoospermia, we designated them as: AZFa, AZFb and AZFc. Their probable phase of function in human spermatogenesis and candidate genes involved will be discussed.

Molecular analysis of the genomic structure of the human Y chromosome in the euchromatic part of its long arm (Yq11).

Conventional methods of long range restriction mapping for analysis of the genomic DNA structure failed in Yq11, because single-copy DNA probes for blot hybridization analyses are rare and the rate of DNA methylation is high in this Y region. Numerous repetitive sequence blocks of unknown extensions are scattered throughout Yq11 and a patchwork of X-Y homologous DNA blocks were found by different investigators. Therefore, our approach towards a molecular analysis of this Y region reduced this complexity by performing first its molecular analysis in YAC clones mapping to Yq11. YACs contain only a part of the whole Yq11 DNA structure. In this paper, we present our first results of this approach based on quantitative blot analysis of 51 DNA loci in 67 YAC clones. The YACs were isolated from the three CEPH libraries and mapped to a contig of 13 Mb from proximal to distal Yq11 with aid of a detailed interval map. In distal Yq11, our analysis revealed the presence of local amplification events of different DNA domains. A model of their possible arrangement is presented.

Global trends in oral and maxillofacial radiology education.

Although the content of the undergraduate dental curriculum has evolved alongside the changes in dental practice, the methods and structure of the course have remained remarkably constant. In this article the recent developments in higher education are reviewed in depth and some changes in the pattern and setting of oral health outlined. Global trends in education in oral and maxillofacial radiology, with particular reference to undergraduate, postgraduate, and continuing professional education, are described against this background.