Routine panoramic radiography of new adult patients in general dental practice: relevance of diagnostic yield to treatment and identification of radiographic selection criteria

Refinement of image quality in panoramic radiography using a generative adversarial network

OBJECTIVE

We aimed to develop and assess the clinical usefulness of a generative adversarial network (GAN) model for improving image quality in panoramic radiography.

METHODS

Panoramic radiographs obtained at Yonsei University Dental Hospital were randomly selected for study inclusion (n = 100). Datasets with degraded image quality (n = 400) were prepared using four different processing methods: blur, noise, blur with noise, and blur in the anterior teeth region. The images were distributed to the training and test datasets in a ratio of 9:1 for each group. The Pix2Pix GAN model was trained using pairs of the original and degraded image datasets for 100 epochs. The peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM) were obtained for the test dataset, and two oral and maxillofacial radiologists rated the quality of clinical images.

RESULTS

Among the degraded images, the GAN model enabled the greatest improvement in those with blur in the region of the anterior teeth but was least effective in improving images exhibiting blur with noise (PSNR, 36.27 > 32.74; SSIM, 0.90 > 0.82). While the mean clinical image quality score of the original radiographs was 44.6 out of 46.0, the highest and lowest predicted scores were observed in the blur (45.2) and noise (36.0) groups.

CONCLUSION

The GAN model developed in this study has the potential to improve panoramic radiographs with degraded image quality, both quantitatively and qualitatively. As the model performs better in refining blurred images, further research is required to identify the most effective methods for handling noisy images.

Retained dental roots of adults: A nationwide population study with panoramic radiographs

The aim of this study was to assess the occurrence and nature of retained dental roots and their associations with demographics in the Finnish adult population. From the cross‐sectional nationwide Health 2000 Survey of the Finnish population aged 30 years and older, 6005 participants with clinical oral examination and panoramic radiographs were included. Occurrence and characteristics of all retained dental roots were examined. Statistical analyses included χ², Kruskal–Wallis and Mann–Whitney U tests, and SAS‐SUDAAN calculations. The mean age of the 6005 participants (46% men and 54% women) was 53 (SD 14.6) years. At least one retained dental root was observed in 13% (n = 754) of the participants. The 1350 retained roots included 461 (34%) roots retained entirely in bone and 889 (66%) partly in bone. The most common location of a retained dental root was the third molar region. Occurrence of retained roots partly in bone was associated with male sex and lower education. Occurrence of retained third molar roots entirely in bone was associated with female sex, younger age, higher education, and living in a city. Among all retained dental roots, the preponderance of third molars emphasized the demanding nature of extracting the third molar in women.

Radiographic Position of Impacted Mandibular Third Molars and Their Association with Pathological Conditions

Objectives

This study aimed to assess the radiographic position of impacted mandibular third molars (IMTMs) and their association with pathological conditions.

Materials and Methods

The impaction depth, relationship with ramus, and angulation of 1600 IMTMs and their association with 2^nd molar distal caries and root resorption, pathological conditions, and proximity to the mandibular canal were evaluated on panoramic radiographs. The IMTM position was determined based on the depth of impaction according to the Pell and Gregory classification, relationship with ramus according to the Pell and Gregory classification, and angulation according to the Winter's classification. The classical and Bayesian logistic regressions were applied to analyze the effect of IMTM position on the associated complications using the odds ratio (OR) and 95% confidence interval (credible interval for Bayesian models). Two-tailed P value < 0.05 was considered statistically significant.

Results

Of 1600 IMTMs evaluated in this study, 195 (12.2%), 252 (15.8%), and 119 (7.4%) had caused second molar distal caries, second molar root resorption, and pathological lesions, respectively, and 872 (54.5%) had contact with the mandibular canal. Impaction angulation was a risk factor for second molar distal caries (maximum OR = 5.01, 95% CI: 3.12-8.18). Changed angulation and greater impaction depth were the risk factors for second molar root resorption (minimum OR = 1.64, 95% CI: 0.58-4.02). Decreased distance between the ramus and distal side of the second molar was a risk factor for associated pathological lesions (minimum OR = 2.73, 95% CI: 1.79-4.25). Mesioangular and horizontal angulations and greater impaction depth were the risk factors for contact with the mandibular canal (maximum OR = 3.44, 95% CI: 2.6-4.57 and minimum OR = 1.3, 95% CI: 094-1.8).

Conclusions

The frequency of complications associated with IMTMs was low, but considerable. The occurrence of these conditions might be affected by the impaction position. Thus, regular follow-ups are recommended in order to be able to surgically intervene when the first signs of pathologies arise.

Panoramic radiography can be an effective diagnostic tool adjunctive to oral examinations in the national health checkup program

Purpose

We investigated correlations between the findings of oral examinations and panoramic radiography in order to determine the efficacy of using panoramic radiographs in screening examinations.

Methods

This study included patients who visited dental clinics at National Health Insurance Service (NHIS) Ilsan Hospital for checkups during 2009–2015 and underwent panoramic radiographic examinations within 1 year prior to the oral examinations. Among the 48,006 patients who received checkups, 1,091 were included in this study. The data were evaluated using the Cohen kappa and interrater agreement coefficients. Accuracy, sensitivity, and specificity were calculated using data from the panoramic radiographs as true positive diagnoses.

Results

The interrater agreement coefficient for occlusal caries was 28.8%, and the Cohen kappa coefficient was 0.043 between the oral and panoramic radiographic examinations. Root caries and subgingival calculus were only found on the radiographs, while gingival inflammation was found only by the oral examinations. The oral examinations had a specificity for detecting occlusal dental caries of 100%, while their sensitivity for proximal dental caries and supragingival calculus was extremely low (14.0% and 18.3%, respectively) compared to the panoramic radiographic examinations. The oral examinations showed a relatively low sensitivity of 66.2% and a specificity of 43.7% in detecting tooth loss compared with panoramic radiography.

Conclusions

Panoramic radiography can provide information that is difficult to obtain in oral examinations, such as root caries, furcation involvement, and subgingival calculus, which are factors that can directly affect the survival rate of teeth. It therefore seems reasonable and necessary to add panoramic radiography to large-scale health checkup programs such as that provided by the NHIS.

Geometric distortion of panoramic reconstruction in third molar tilting assessments: a comprehensive evaluation

OBJECTIVES:

To evaluate the geometric distortion of tilting of mandibular third molars with respect to second molars on panoramic reconstruction.

METHODS:

Cone-beam CT (CBCT) reconstructions of 160 third molars, obtained due to an indication of risk of inferior alveolar nerve damage during surgery, were used. CBCT-reconstructed panoramic images were used as bi-dimensional (2D) images, to avoid distortions other than geometric distortions. The angle between the second and the third molar was measured in 2D and three-dimensional (3D) images. Student's t-test was used to assess the null-hypothesis of no difference between 2D and 3D measurements.

RESULTS:

A significant mean difference (-2.3° ± 6.3°) between 2D and 3D measurements was found, with an absolute error of 3.6° ± 5.7° and a relative error of 10%. These findings comprehensively explain the geometric distortion on panoramic radiographs.

CONCLUSIONS:

Although a widely used and undoubtedly useful tool for diagnosis and surgical planning of mandibular third molar extractions, panoramic reconstruction are biased from geometric distortion that may influence surgical planning.

Dental Students' Interpretations of Digital Panoramic Radiographs on Completely Edentate Patients

The ability of dental students to interpret digital panoramic radiographs (PANs) of edentulous patients has not been documented. The aim of this retrospective study was to compare the ability of second-year (D2) dental students with that of third- and fourth-year (D3-D4) dental students to interpret and identify positional errors in digital PANs obtained from patients with complete edentulism. A total of 169 digital PANs from edentulous patients were assessed by D2 (n=84) and D3-D4 (n=85) dental students at one Canadian dental school. The correctness of the students' interpretations was determined by comparison to a gold standard established by assessments of the same PANs by two experts (a graduate student in prosthodontics and an oral and maxillofacial radiologist). Data collected were from September 1, 2006, when digital radiography was implemented at the university, to December 31, 2012. Nearly all (95%) of the PANs were acceptable diagnostically despite a high proportion (92%) of positional errors detected. A total of 301 positional errors were identified in the sample. The D2 students identified significantly more (p=0.002) positional errors than the D3-D4 students. There was no significant difference (p=0.059) in the distribution of radiographic interpretation errors between the two student groups when compared to the gold standard. Overall, the category of extragnathic findings had the highest number of false negatives (43) reported. In this study, dental students interpreted digital PANs of edentulous patients satisfactorily, but they were more adept at identifying radiographic findings compared to positional errors. Students should be reminded to examine the entire radiograph thoroughly to ensure extragnathic findings are not missed and to recognize and report patient positional errors.

Panoramic radiographs made before complete removable dental prostheses fabrication: A retrospective study of clinical significance

STATEMENT OF PROBLEM

The value of digital panoramic radiographs to screen for problems before fabricating conventional complete dentures is unclear.

PURPOSE

The purpose of this retrospective study was to examine the influence of pretreatment digital panoramic radiographs on the clinical management of patients receiving complete removable dental prostheses.

MATERIAL AND METHODS

The clinical records, including panoramic radiographs, of 169 patients seeking new complete removable dental prostheses over a 6-year period were interpreted independently by both a prosthodontist and an oral and maxillofacial radiologist to identify radiographic findings that influenced clinical patient management. A 95% confidence interval and an observed proportion of agreement were used to interpret the results.

RESULTS

Sixty percent of the 169 radiographs examined had 1 or more abnormal or positive radiographic findings; however, only 6 (<4%) of 165 abnormalities detected influenced patient management, and 3 of them were identified during the clinical examination.

CONCLUSIONS

Pretreatment digital panoramic radiographs revealed very few abnormalities that influenced the treatment of patients requiring complete removable dental prostheses. Furthermore, the digital images in this study revealed positive findings at a rate similar to those found in studies assessing analog radiographs, reinforcing current guidelines that recommend against radiographic screening of patients who seek new complete removable dental prostheses.

Rescue of a periodontally compromised tooth by non-surgical treatment: a case report

PURPOSE

This article describes a case of the successful non-surgical management of a periodontally compromised maxillary premolar.

METHODS

A combination therapy, including root planing, occlusal adjustment, and tooth splinting, was applied. Clinical and radiographic examinations were performed during the 16-month follow-up period.

RESULTS

All periodontal parameters were improved. There were dramatic decreases (3-6 mm) in the probing pocket depth, tooth mobility, and marginal bone loss. Interestingly, gradual resolution of the periapical radiolucency and alveolar bone regeneration were observed in the radiographs, and the periodontal condition was maintained during the follow-up period.

CONCLUSIONS

Within the limits of this study, these results demonstrate the importance of natural tooth preservation through proper periodontal treatment and occlusal adjustment of the periodontally compromised tooth, which is typically targeted for tooth extraction and dental implantation.

Recent advances in imaging technologies in dentistry

Dentistry has witnessed tremendous advances in all its branches over the past three decades. With these advances, the need for more precise diagnostic tools, specially imaging methods, have become mandatory. From the simple intra-oral periapical X-rays, advanced imaging techniques like computed tomography, cone beam computed tomography, magnetic resonance imaging and ultrasound have also found place in modern dentistry. Changing from analogue to digital radiography has not only made the process simpler and faster but also made image storage, manipulation (brightness/contrast, image cropping, etc.) and retrieval easier. The three-dimensional imaging has made the complex cranio-facial structures more accessible for examination and early and accurate diagnosis of deep seated lesions. This paper is to review current advances in imaging technology and their uses in different disciplines of dentistry.

Exames radiográficos solicitados no atendimento inicial de pacientes em uma Faculdade de Odontologia brasileira

INTRODUÇÃO: Para que radiografias ofereçam mais benefícios do que riscos, precisam ser realizadas ou solicitadas de acordo com cada situação clínica.OBJETIVO: Avaliar os exames radiográficos solicitados no atendimento inicial em uma Faculdade de Odontologia, considerando os sinais/sintomas e o motivo para busca pelo atendimento.MATERIAL E MÉTODO: Foram avaliados os prontuários de 3.100 pacientes adultos, tratados em um período de três anos, excluindo aqueles em que os pacientes não haviam realizado exames radiográficos na consulta inicial. Numa amostra final de 1.567 prontuários, foram coletados os seguintes dados: idade e gênero, razão da procura pelo tratamento, presença de sinais e/ou sintomas, além da técnica e do número de radiografias realizadas. Os dados foram analisados por estatística descritiva.RESULTADO: 5.034 radiografias realizadas, com média de 3,24 (±2,97) por paciente. Entre as técnicas, a mais utilizada foi a periapical seguida pela panorâmica. Extração dentária e dor foram as razões mais prevalentes da procura pelo atendimento, enquanto dor, doença periodontal e presença de patologias de tecidos moles foram os sinais/sintomas mais comuns. Verificou-se que 35,41% da amostra não apresentou sinais ou sintomas.CONCLUSÃO: Há uma grande variação na requisição de radiografias no exame inicial, mostrando uma falha na aplicação de critérios de seleção de imagens para diagnóstico, o que pode levar à exposição desnecessária do paciente à radiação X.

Comparison of clinical and dental panoramic findings: a practice-based crossover study

BACKGROUND

Aim was to compare clinical findings with x-ray findings using dental panoramic radiography (DPR). In addition, type and frequency of secondary findings in x-rays were investigated.

METHODS

Patients were selected on the basis of available DPRs (not older than 12 months). No therapeutic measures were permitted between the DPR and the clinical findings. The clinical findings were carried out by several investigators who had no knowledge of the purpose of the study. A calibrated investigator established the x-ray findings, independently and without prior knowledge of the clinical findings. The evaluation parameters for each tooth were: missing, healthy, carious, restorative or prosthetically sufficient or insufficient treatment. Type and frequency of additional findings in the DPR were documented, e.g. quality of a root canal filling and apical changes.

RESULTS

Findings of 275 patients were available. Comparison showed a correspondence between clinical and radiographic finding in 93.6% of all teeth (n = 7,789). The differences were not significant (p > 0.05). Regarding carious as well as insufficiently restored or prosthetically treated teeth, respectively there were significant differences between the two methods (p < 0.05). The DPRs showed additional findings: root fillings in 259 teeth and 145 teeth with periapical changes.

CONCLUSIONS

With reference to the assessment of teeth, there was no difference between the two methods. However, in the evaluation of carious as well as teeth with insufficiently restorative or prosthetic treatment, there was a clear discrepancy between the two methods. Therefore, it would have been possible to have dispensed with x-rays. Nevertheless, additional x-ray findings were found.

A study to determine the added value of 740 screening panoramic radiographs compared to intraoral radiography in the management of adult (>18 years) dentate patients in a primary care setting

OBJECTIVES

To measure the added value of panoramic radiography in new dentate patients attending for routine treatment.

METHODS

Thirty-seven general dental practitioners using panoramic radiographs routinely were recruited. Twenty dentate patients were identified prospectively by each participating dentist if they were new to the practice, attending for an examination and requesting any treatment deemed necessary. A panoramic radiograph was taken with appropriate intraoral radiographs in line with national guidelines. Each dentist completed a radiological report for the panoramic radiograph only and these 20 reports were forwarded to the researchers along with the 20 panoramic radiographs, their accompanying bitewing and periapical radiographs and twenty completed clinical assessment sheets.

RESULTS

740 panoramic, 1418 bitewing and 325 periapical radiographs were assessed by the researchers. Only 32 panoramic films provided any additional diagnostic value when compared to intraoral films when guidelines had been observed resulting from the poor technical and processing quality of the accompanying intraoral films. Assessment of the number of caries and periapical lesions and the degree of periodontal bone loss from the intraoral films provided a greater diagnostic yield at the p<0.001 level of significance. The research found that dentists underestimated the number of caries lesions present and level of periodontal bone loss when compared to the researchers but overestimated the presence of periapical pathology, at the level of significance at p<0.001.

CONCLUSIONS

The study found that there was no support for the use of panoramic radiographs in routine screening as there was no net diagnostic benefit to the patient.

Assessment of panoramic radiography as a national oral examination tool: review of the literature

Purpose

The purpose of this review is to evaluate the possibility of panoramic radiography as a national oral examination tool.

Materials and Methods

This report was carried out by review of the literatures.

Results

Panoramic radiography has sufficient diagnostic accuracy in dental caries, periodontal diseases, and other lesions. Also, the effective dose of panoramic radiography is lower than traditional full-mouth periapical radiography.

Conclusion

Panoramic radiography will improve the efficacy of dental examination in national oral examination. However, more studies are required to evaluate the benefit, financial cost, and operation time and also to make selection criteria and quality management program.

Initial periodontal screening and radiographic findings--a comparison of two methods to evaluate the periodontal situation

BACKGROUND

The periodontal screening index (PSI) is an element of the initial dental examination. The PSI provides information on the periodontal situation and allows a first estimation of the treatment required. The dental panoramic tomography (DPT) indicates the proximal bone loss, thus also allowing conclusions on the periodontal situation. In this study, the results of both methods in determining the periodontal situation are compared.

METHODS

The clinical examination covered DMF-T, QHI, and PSI scores at four proximal sites per tooth; the examining dentist was unaware of the radiographic finding. Based on the PSI scores, the findings were diagnosed as follows: score 0 - 2 "no periodontitis", score 3 and 4 "periodontitis". Independent of the locality and time of the clinical evaluation, two dentists examined the DPTs of the subjects. The results were classified as follows: no bone loss = "no periodontitis", and bone loss = "periodontitis".

RESULTS

112 male subjects (age 18 to 58, Ø 37.7 ± 8 years) were examined. Regarding the PSI, 17 subjects were diagnosed "no periodontitis" and 95 subjects "periodontitis". According to the evaluation of the DPTs, 70 subjects were diagnosed "no periodontitis" and 42 "periodontitis". A comparison of both methods revealed that the diagnosis "no periodontitis" corresponded in 17 cases and "periodontitis" in 42 cases (53%). In 47% (53 cases) the results were not congruent. The difference between both methods was statistically significant (p < 0.001; kappa = 0.194).

CONCLUSION

The present study shows that the initial assessment of the periodontal situation significantly depends on the method of evaluation.

Assessment of trabecular pattern on periapical and panoramic radiographs: a pilot study

OBJECTIVE

This methodological study aimed to determine whether the mandibular trabecular bone assessment from panoramic radiographs, using a visual index, corresponds to the evaluation obtained from periapical radiographs.

MATERIAL AND METHODS

A panoramic radiograph and corresponding periapical radiographs of the region of the lower premolars and molars were collected from each of 32 patients (mean age 18.5 +/- 5.5 years). Two calibrated observers assessed randomly the interdental sites between the first molar and second premolar and between the two premolars on all the radiographs using a visual index. Evaluations were repeated with an interval of 60 days. The results of the repeated evaluations were used to assess intra- and inter-observer agreements, employing Kappa statistics. Spearman's correlation was used to determine the association between assessments of panoramic and periapical radiographs.

RESULTS

In total, 79 interdental sites were evaluated on the panoramic and periapical radiographs. The visual analysis of periapical radiographs revealed intra-observer agreements of 0.88 for observer 1 and 0.93 for observer 2, and an inter-observer agreement of 0.82. The intra-observer agreement for panoramic radiographs was 0.79 and 0.83 for observers 1 and 2, respectively, and the inter-observer agreement was 0.79. A substantial correlation was found between periapical and panoramic radiographs (rho = 0.737, p = 0.001).

CONCLUSIONS

Although panoramic radiographs are less reliable than periapical radiographs, they can be used for assessment of the trabecular bone pattern with the aid of a visual index. Training on the method is recommended to obtain results with a high reproducibility.

Classifying degenerative joint disease by the RDC/TMD and by panoramic imaging: a retrospective analysis

The purposes of the study were to evaluate the utility of diagnosing degenerative joint disease (DJD) by the clinical finding of coarse crepitus alone, without supporting imaging studies, as defined by the RDC/TMD, and to evaluate the contribution of panoramic radiography as an aid in the diagnosis of DJD. A retrospective analysis of 372 consecutive patients with TMD was conducted. Their panoramic radiographs were evaluated for the extent of their contribution to the final diagnosis. Panoramic radiography was of no diagnostic value in 94.4% of the cases when the group was considered as a whole. When patients diagnosed with DJD were considered separately, panoramic radiography was completely sufficient for reaching the final diagnosis in 20.0% of the cases. In almost 90% of these patients, however, the clinical examination did not support the diagnosis of DJD (no coarse crepitus was found). This raises some doubts about the effectiveness of the clinical examination according to the RDC/TMD and about the utility of panoramic radiography in the definitive diagnosis of DJD, because both techniques have low accuracy (11.1% and 20%, respectively). The present study supports the current recommendations that panoramic radiography should not be ordered routinely to assess DJD, but still it is first choice when any dental problem is suspected. Further additional imaging (computerized tomography, magnetic resonance imaging) should be considered only if there is reason to expect that the findings might affect diagnosis and management. This study adds to recent criticisms of the clinical validity of the RDC/TMD, with regard to DJD.

The utility of panoramic radiography in temporomandibular joint assessment

OBJECTIVES

Panoramic radiography was used to determine (1) intrarater and inter-rater reliability in assessing temporomandibular joint (TMJ) condylar morphology; (2) alteration in condylar shape in patients with temporomandibular disorders (TMD) and controls when matched by age, gender, and state of dentition; and (3) prevalence of condylar abnormalities in individuals with and without TMD.

METHODS

One hundred panoramic radiographs were randomly selected from a hospital clinic (45 TMD and 55 non-TMD patients). The images were cropped to include only the temporomandibular apparatus and were independently evaluated by three examiners without knowledge of the patient's clinical status. Multiple statistical tests were performed to evaluate the accumulated data.

RESULTS

Intrarater reliability demonstrated substantial agreement, while inter-rater reliability was fair. There was no difference in condylar morphology between patient groups, but mild condylar change was prevalent in all age groups, regardless of TMD status.

CONCLUSIONS

Morphological condylar abnormalities are present on panoramic images in all adult age ranges, regardless of status of the dentition or presence of TMD. Condylar shape alone is not an indicator of TMD, and minor condylar discrepancies may have no significance in TMD.