Panoramic imaging errors in machine learning model development: a systematic review.

OBJECTIVES: To investigate the management of imaging errors from panoramic radiography (PAN) datasets used in the development of machine learning (ML) models. METHODS: This systematic literature followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and used three databases. Keywords were selected from relevant literature. ELIGIBILITY CRITERIA: PAN studies that used ML models and mentioned image quality concerns. RESULTS: Out of 400 articles, 41 papers satisfied the inclusion criteria. All the studies used ML models, with 35 papers using deep learning (DL) models. PAN quality assessment was approached in 3 ways: acknowledgement and acceptance of imaging errors in the ML model, removal of low-quality radiographs from the dataset before building the model, and application of image enhancement methods prior to model development. The criteria for determining PAN image quality varied widely across studies and were prone to bias. CONCLUSIONS: This study revealed significant inconsistencies in the management of PAN imaging errors in ML research. However, most studies agree that such errors are detrimental when building ML models. More research is needed to understand the impact of low-quality inputs on model performance. Prospective studies may streamline image quality assessment by leveraging DL models, which excel at pattern recognition tasks.

Career-computer simulation increases perceived importance of learning about rare diseases.

BACKGROUND: Rare diseases may be defined as occurring in less than 1 in 2000 patients. Such conditions are, however, so numerous that up to 5.9% of the population is afflicted by a rare disease. The gambling industry attests that few people have native skill evaluating probabilities. We believe that both students and academics, under-estimate the likelihood of encountering rare diseases. This combines with pressure on curriculum time, to reduce both student interest in studying rare diseases, and academic content preparing students for clinical practice. Underestimation of rare diseases, may also contribute to unhelpful blindness to considering such conditions in the clinic. METHODS: We first developed a computer simulation, modelling the number of cases of increasingly rare conditions encountered by a cohort of clinicians. The simulation captured results for each year of practice, and for each clinician throughout the entirety of their careers. Four hundred sixty-two theoretical conditions were considered, with prevalence ranging from 1 per million people through to 64.1% of the population. We then delivered a class with two in-class on-line surveys evaluating student perception of the importance of learning about rare diseases, one before and the other after an in-class real-time computer simulation. Key simulation variables were drawn from the student group, to help students project themselves into the simulation. RESULTS: The in-class computer simulation revealed that all graduating clinicians from that class would frequently encounter rare conditions. Comparison of results of the in-class survey conducted before and after the computer simulation, revealed a significant increase in the perceived importance of learning about rare diseases (p < 0.005). CONCLUSIONS: The computer career simulation appeared to affect student perception. Because the computer simulation demonstrated clinicians frequently encounter patients with rare diseases, we further suggest this should be considered by academics during curriculum review and design.

A simple radiographic approach to maxillary pathologies.

This article describes an intraoral radiographic technique for identifying lesions located on the buccal surfaces of the maxillary alveolar process. An intraoral film is placed behind the maxillary tuberosity and the X-ray beam exposes the film perpendicularly, running laterally to the buccal surface of the cortical bone. As a result, any external alteration can be seen clearly, with no superimposed maxillary teeth or osseous tissues.

Impact of landmark identification and standard measurement error on cephalometric analysis using a mathematical simulation model / Impacto da identificação do ponto anatômico e do erro padrão de mensuração na análise cefalométrica utilizando um modelo de simulação matemática

Objective: To assess, using a mathematical simulation model, the participation of each coordinate involved in the formation of cephalometric angles and to determine the extent to which errors in the identification of cephalometric landmarks can, individually and collectively, influence the measurement of these angles. Material and Methods: The reference values and standard errors of 13 landmarks obtained from the analysis of 30 cephalograms were used. For each landmark, 1000 observations were simulated using the Monte Carlo method. On the basis of linear regression models, equations designed to estimate measurement errors due to landmark identification errors were obtained and analysed. Results: The coordinates most involved in the formation of the angles SNA, SNB, ANB, FMA, PPL, DFC, and AEF were Ny, Ny, Ax, Goy, Poy, Poy, and Ptmx, respectively, and the standard measurement errors for these angles were 1.2, 0.9, 0.8, 1.6, 1.5, 1.5, and 1.4, respectively. Conclusion: The standard measurement error of the angle depends on the geometric impact coefficient and the standard error of the coordinates involved in the formation of the angles, and the geometric impact coefficient varies according to the angle analysed.

Objetivos: Avaliar, empregando um modelo matemático de simulação, a participação de cada coordenada envolvida na formação de ângulos cefalométricos, assim como determinar a extensão da influência dos erros na identificação dos pontos cefalométricos, individual e coletivamente, na mensuração destes ângulos. Materiais e métodos: Foram utilizados os valores de referência e os erros padrão de 13 pontos anatômicos obtidos a partir da análise de 30 cefalogramas. Para cada ponto anatômico, foram simuladas 1000 observações utilizando o método de Monte Carlo. Com base em modelos de regressão linear, foram obtidas e analisadas equações destinadas a estimar os erros de medição devido a erros na identificação dos pontos cefalométricos. Resultados: As coordenadas mais envolvidas na formação dos ângulos SNA, SNB, ANB, FMA, PPL, DFC, e AEF foram Ny, Ny, Ax, Goy, Poy, Poy, e Ptmx, respectivamente, e os erros padrão de mensuração destes ângulos foram 1,2; 0,9; 0,8; 1,6; 1,5; 1,5 e 1,4, respectivamente. Conclusões: O erro padrão de mensuração de cada ângulo cefalométrico depende do coeficiente de impacto geométrico e do erro padrão das coordenadas dos pontos anatômicos envolvidos na formação dos mesmos, sendo que o coeficiente de impacto geométrico varia de acordo com o ângulo analisado.

Topographic relationship of impacted third molars and mandibular canal: correlation of panoramic radiograph signs and CBCT images

Aim: This study evaluated the proximity and relation of impacted lower third molars and mandibular canal on panoramic radiography. Methods: Radiographic signals associated with proximity of structures and Pell & Gregory and Winter classifications of 78 impacted teeth were analyzed and compared with CBCT images (gold standard). The associations between the findings were tested with Pearson’s chi-square. Results: Direct contact between structures was observed in 85% ofcases of radiolucent band over roots. Conclusions: Radiolucent band over roots is the image more associated with direct contact between structures and the one that indicates lingual positioning of the canal more consistently. Some categories of Pell & Gregory and Winter classifications suggested signs of the topographic location of the mandibular canal.

A comparative study of lateral cephalograms and cone-beam computed tomographic images in upper airway assessment.

The purpose of this study was to evaluate the accuracy of airway measurements from lateral cephalograms, cone-beam computed tomographic (CBCT) lateral reconstructions, and CBCT axial planes, as well as to correlate these findings with area measurements acquired with the latter imaging method. Landmarks were defined for the measurements of naso- and oropharynx of 30 patients (12 males and 18 females, mean age 17.5 years), for different planes, using linear antero-posterior measurements and the corresponding area. Analysis of variance showed significant differences in the linear measurements of the oropharynx between the two methods, although all measurements assessed corresponded to the respective areas. The linear measurements of the airway space obtained using the different techniques correlated positively with the respective area measurements, which demonstrate the reliability of the investigated techniques.

Anquilose alvéolo-dentária em molares decíduos: revisão de literatura e apresentação de casos clínico-cirúrgicos / Ankylosis in primary molars: a review of literature and presentation of clinical cases

Os autores apresentam revisão de literatura sobre anquilose dentária na dentição decídua e relatam dois casos clínicos com tratamento cirúrgico: um em paciente jovem com descoberta precoce da anquilose dos dentes 75 e 85, tratado clinicamente com colocação de dispositivo em resina composta para manutenção da oclusão, sem sucesso e com subseqüente submersão do dente e outro, em paciente adulto, sem tentativa de tratamento clínico e com submersão do dente 55 e giroversão do 15 erupcionado