Radiation exposure during orthodontic treatment: risk to children and adolescents.

OBJECTIVES: To estimate radiation risk to children and adolescents during orthodontic treatment by retrieving number and type of radiographs from the patient records. MATERIAL AND METHODS: Radiographs, along with justifications for radiation exposure, were obtained retrospectively from the patient records of 1,790 children and adolescents referred to two Swedish orthodontic clinics. Data were grouped according to treatment stage: treatment planning, treatment, and follow-up. Estimated risk was calculated using the concept of effective dose. RESULTS: Each patient had received around seven radiographs for orthodontic purposes. The most common exposures during treatment planning were one panoramic, one lateral, and three intraoral periapical radiographs. A small number of patients received a tomographic examination (8.2%). Few justifications for treatment planning and follow-up, but more in the actual treatment stage, had been recorded. The most common examinations were to assess root resorption and the positions of unerupted teeth, or simply carry out an unspecified control. The estimated risk of developing fatal cancer was considered low. The radiation risk from orthodontic treatment was equivalent to about 5-10 days of natural background radiation. CONCLUSIONS: Children and adolescents sometimes undergo multiple radiographic examinations, but despite the low radiation burden, accumulated radiation exposure should be considered and justified in young patients.

Choice of radiography in orthodontic treatment on children and adolescents: A questionnaire-based study performed in Sweden.

The aim was to investigate the objective and choice of different radiographic examinations used in orthodontic treatment of children and adolescents, using a web-based questionnaire directed toward specialists in orthodontics. The questionnaire was distributed to 255 orthodontists in Sweden. In total, 142 responses were received, and 11 specialists were interviewed. Questions were related to the use of radiography during different treatment stages; modifications to the treatment regimen owing to radiographic findings; and the use of and/or need for guidelines in radiography. Radiographic examinations were performed in all treatment stages and mainly during treatment planning. Panoramic radiographs were always or often used by the respondents (99%), less frequently used were lateral radiographs (66%) and intra-oral radiographs of the incisor regions (69%). Cone beam computed tomography (CBCT) was sparsely employed. A majority of the respondents considered that radiographic findings often or occasionally affected the treatment. Local- or clinic-specific guidelines were used by 85% of respondents. The need for national guidelines was considered low. The frequent use of panoramic radiography together with application of local guidelines, may indicate that radiographic selection criteria are not individualised. National guidelines might facilitate updates on radiographic techniques, and on radiation doses and risks in young patients.

Reliability of marginal bone level measurements on digital panoramic and digital intraoral radiographs.

OBJECTIVES: The aim of this study was to evaluate the reliability of bitewing and panoramic radiographs in marginal bone level measurements in terms of inter- and intra-observer agreement. METHODS: Fifty paired bitewing and panoramic images were used. Eight observers measured marginal bone level at the mesial and distal surfaces of tooth 25 and tooth 35. Thus, in total 100 radiographs of 400 measurements were obtained for each observer. To evaluate intra-observer agreement, three observers re-evaluated the radiographs after a minimum of 1 month. Intra-class correlation coefficient (ICC) was applied to evaluate the inter- and intra-observer agreement. The t test was applied to assess possible difference in measurement between bitewing and panoramic radiographs. RESULTS: The mean ICC value of inter-observer agreement was 0.85 for bitewing and 0.66 for panoramic radiographs. The mean intra-observer agreement was 0.92 and 0.76 for bitewing and panoramic radiographs, respectively. There was no statistically significant difference between bitewing and panoramic radiographs in measurements of marginal bone level on maxillary tooth 25, whereas a statistically significant difference was found between the two image modalities on mandible tooth 35. CONCLUSION: Bitewing examination should be the choice of image modality for assessment of marginal bone level at premolar region due to good to excellent reliability and low radiation dose. However if a panoramic radiograph already exists, a rough estimation of marginal bone level at premolar region is clinically acceptable bearing in mind that the bone height of the mandible premolar region might be overestimated as compared to bitewing radiograph.

Timing of mineralization of homologues permanent teeth--an evaluation of the dental maturation in panoramic radiographs.

Clinically the condition Molar Incisor Hypomineralization (MIH),varies considerably between individuals, where any number of molars, from one to all four permanent first molars, may be affected with different degrees of hypomineralized enamel within the same dentition. An explanation to these variations could be that the start of the enamel mineralization differs between homologues teeth. The aim of this study was to compare the dental development between homologues teeth in digital panoramic radiographs (PRs),from children aged 7 to 11 years, using the Gleiser & Hunt method on second and third molars and to calculate the crown/root ratio for the mandibular premolars.77 PRs, from individuals between 7.3 and 11.0 years of age, were studied. Differences in developmental stages between homologues teeth (second and third molars) were studied. In 72 of these PRs, the crown/root ratio of mandibular premolars was also compared. In 31 of the PRs, a difference in development was found between the right and left maxillary second molar. In 22 PRs, a difference in development between the right and left mandibular second molar was found. In 17 of the PRs, a difference in development was found between the right and left maxillary third molars. In 26 PRs,a difference in-between the right and left mandibular third molar was found. In 72 PRs, the crown/root ratio of mandibular premolars was measured and differences were found. All these differences were significant. A possible explanation to the variations in expressivity of MIH may be a result of differences in the start of mineralization between homologues teeth. Timing of mineralization of homologues permanent teeth--An evaluation of the dental maturation in panoramic radiographs.

Approximal caries increment in adolescents after a visual aid in combination with a comprehensive open discussion.

OBJECTIVE: To achieve greater motivation for behavioural changes; educating, motivating and supporting the patient's ability to change lifestyle factors related to the caries disease are important tasks in the prevention of the disease. The aim of this study was to evaluate whether a visual aid (Visual Caries Dialogue, VCD) in combination with a comprehensive open discussion has a beneficial effect on approximal caries development among a population of young adolescents. MATERIALS AND METHODS: The study subjects were randomized to either an intervention group (n = 118), where VCD was conducted, or a control group (n = 112) receiving traditional oral healthcare information, at the annual dental health examination. The number of caries lesions reaching through the entire enamel (D2) and dentin caries reaching through the enamel into the dentin (D3) were recorded from bitewing radiographs each year, from 2001-2004. Differences between the study groups regarding at least two new approximal surfaces with caries (D2-D3) were tested using logistic regression. RESULTS: The caries increment was lower in the intervention group compared to the control group. During the 3-year follow-up, 18 (15.3%) patients in the intervention group and 40 (35.7%) patients in the control group demonstrated a DS-approximal increment of at least two surfaces with a risk ratio of 2.34 (95% CI = 1.43-3.83). CONCLUSION: Visual Caries Dialogue in combination with a comprehensive open discussion reduced approximal caries increment among young individuals. The method provides an innovative simple and low-cost way of delivering information to patients and guides busy dental healthcare personnel in the approach.

Frequency of errors and pathology in panoramic images of young orthodontic patients.

The aims of this study were to evaluate the frequency of errors in panoramic radiographs in young orthodontic patients, to register pathologic and abnormal conditions, and to compare these findings with the patient's record. A total of 1287 panoramic radiographs of children and adolescents (530 boys and 757 girls; mean age 14.2 years) were analyzed. The radiographs were obtained of patients referred for orthodontic treatment during a 1 year period. Four observers evaluated the radiographs for 10 common errors, pathologies, and/or anomalies. Cohen's kappa was used for the calculations of inter- and intraobserver variability. Five of the errors were divided into clinically relevant or not clinically relevant errors, i.e. errors influencing diagnosis. Only those pathological findings with a possible influence on orthodontic treatment were compared with the patient's record. Of the 1287 radiographs, 96 per cent had errors. The number of errors in each image varied between 1 and 5, and in 24 per cent of these images, the errors could be of importance for clinical decision making. The most common error was that the tongue was not in contact with the hard palate. Pathologies or anomalies were found in 558 patients and a total of 1221 findings were recorded. Findings of possible relevance for orthodontic treatment were 63, and 12 of those were registered in the patient records. Pathological findings outside the dental arches were low and could be an argument for minimizing the radiation field.

Evaluation of VPI-assessment with videofluoroscopy and nasoendoscopy.

UNLABELLED: The purpose of this study was to investigate how different amounts of visual assessment information influence the recommended treatment for velopharyngeal insufficiency (VPI). Is a patient presented with videofluoroscopy (VF) in lateral projection recommended the same treatment as when frontal projection, nasoendoscopy, or both, are added? Retrospective material with video recorded assessment of VPI was blinded and copied in random order. Each patient was then presented in four separate combinations: VF in lateral projection; VF in lateral and frontal projection; VF in lateral projection and nasoendoscopy; and VF in lateral and frontal projection and nasoendoscopy (all of the available assessment material). The cleft palate team of Göteborg, Sweden, mutually rated velopharyngeal function and recommended action based on the presented material. SUBJECTS: Nineteen consecutive patients (median age 7:5 years, range 4:4-19:7) investigated with VF in lateral and frontal projection and nasoendoscopy during 1997-99 at the cleft palate centre in Göteborg, Sweden. Post operative assessments were excluded. Percent agreement and Kappa calculations were used to compare the different combinations of parts of information to all of the available information. RESULTS: Thirteen of the 19 patients (68%) were recommended the same action regardless of the amount of presented information. Percent agreement (Kappa) between parts and all of the available information: VF in lateral projection 84% (0.75), VF in lateral and frontal projection 79% (0.74), and VF in lateral projection and nasoendoscopy 84% (0.72). CONCLUSIONS: VF in lateral projection is recommended to be the first step in visualising velopharyngeal function, and nasoendoscopy the next when further investigation is required.

Effect of school-based fluoride varnish programmes on approximal caries in adolescents from different caries risk areas.

The aim was to evaluate, in a 3-year RCT study, school-based fluoride varnish programme on approximal caries incidence and approximal caries progression in 13- to 16-year-olds in high, medium and low caries risk areas on the Swedish west coast. Seven hundred and fifty-eight (89%) fulfilled the trial. Using a simple mobile unit, 2 dental nurses treated the adolescents with F varnish: (1) twice a year at 6-month intervals, (2) 3 times a year within 1 week, (3) 8 times per year during the semesters with 1-month intervals, and (4) no treatment (control). Radiographic caries recording was performed blindly by one of the authors. Concerning total approximal caries incidence, control groups in all areas developed more caries than F varnish groups, with the largest difference in the high risk area: 3.05 +/- 3.37 new approximal caries lesions (mean +/- SD) compared to 0.54 +/- 1.26 for group 3, 0.95 +/- 1.67 for group 1 and 1.40 +/- 1.89 for group 2 (p < 0.001). More than 90% of the new approximal lesions in all the groups and in all areas consisted of new enamel lesions. Regarding progression of enamel lesions, there were only significant differences between groups 1-3 and group 4 in the high caries risk area. Prevented fraction for fluoride varnish treatment twice a year at 6-month intervals was 69% in high, 66% in medium and 20% in low risk areas. To conclude, school-based F varnish treatment every 6 months in 13- to 16-year-olds is excellent to prevent approximal caries in medium and high caries risk areas.

Perceptual analysis of speech and the activity in the lateral pharyngeal walls before and after velopharyngeal flap surgery.

The purpose of this study was to investigate the effects of velopharyngeal flap surgery on speech and its relation with the activity in the lateral pharyngeal walls. Videofluoroscopic recordings made before and after operation were used in this retrospective study, which comprised 28 patients who had pharyngeal flap surgery between 5:5 and 14:3 (mean 8:6) years:months of age at the Sahlgrenska University Hospital, Göteborg, Sweden. Twenty-four patients had different types of clefts and four had velopharyngeal impairment (VPI) without a cleft palate. Eleven had additional malformations. Speech and activity in the lateral pharyngeal walls were perceptually preoperatively and postoperatively. The study confirmed that patients with VPI can be helped by a velopharyngeal flap operation. There seemed to be a relation with the activity in the lateral pharyngeal wall and speech. The later the postoperative assessment, the better the speech, but the age at operation did not affect the result. The impact of additional anomalies and syndromes should be investigated further.