T-Scan Novus System in the Management of Splints—Pilot Study

The purpose of this pilot study was to demonstrate the capabilities of the T-Scan Novus system in bruxism treatment by splints. Bruxism patients underwent treatment with a splint made by additive manufacturing. Intraoral scanning was performed using Trios Color (3Shape), and digital design was performed using 3Shape Dental system design - splint studio. The biocompatible material Dental LT Clear Resin was printed using a Formlabs Form 2 printer. The T-Scan Novus system with a software attached to it, version 9.1, was used for digital examination of the occlusion. A splint with an occlusal thickness of 2.5 mm was developed and software adapted with relief to antagonists. The digitally set occlusion with even contacts turned out to be clinically unbalanced. After adjusting with T-Scan Novus, a balanced occlusion was achieved in the right and left halves. The treatment of bruxism with splint therapy continues to be the main method. Its combination with digital technologies allows more precise constructions and more accurate balancing of occlusal relationships.

Prediction of non-reassuring fetal status and umbilical artery acidosis by the maternal characteristic and ultrasound prior to induction of labor

Objective To investigate the predictive value of pre-induction digital examination, sonographic measurements and parity for the prediction of non-reassuring fetal status and cord arterial pH < 7.2 prior to the induction of labor (IOL). Method This was a prospective observational study, including 384 term pregnancies undergoing IOL. Before the IOL, the Bishop score (BS) by digital examination, sonographic Doppler parameters and the estimated fetal weight (EFW) was assessed. The fetal cord arterial was sampled to measure the pH at delivery. Multivariate logistic regression analysis was performed to identify independent predictors of non-reassuring fetal status and low cord arterial pH. Results Forty four cases (11.5%) had non-reassuring fetal status, and 76 cases (19.8%) had fetal cord arterial pH < 7.2. In the non-reassuring fetal status group, the incidence of cord arterial pH < 7.2 was significantly higher than that in the normal fetal heart rate group (χ2 = 6.401, p = 0.011). Multivariate analysis indicated that significant independent predictors of non-reassuring fetal status were nulliparity (adjusted odds ratio [AOR]: 3.746, p = 0.003), EFW < 10th percentile (AOR: 3.764, p = 0.003) and cerebroplacental ratio (CPR) < 10th centile (AOR:4.755, p < 0.001). In the prediction of non-reassuring fetal status, the performance of the combination of nulliparity and EFW < 10th percentile was improved by the addition of CPR < 10th percentile (AUC: 0.681, (95%CI: 0.636 to 0.742) vs 0.756, (95%CI:0.713 to 0.795)), but the difference was not significant (DeLong test: z = 1.039, p = 0.053).. None of the above variables were predictors of cord arterial pH < 7.2. Conclusion The risk of fetal acidosis has increased in cases of non-reassuring fetal status. Nulliparity, small for gestational age and CPR < 10th centile are independent predictors for non-reassuring fetal status in term fetuses, though the addition of CPR < 10th centile could not significantly improve the screening accuracy.

Digital Quantification of Occlusal Contacts: A Methodological Study

Objective: To compare the reliability of digital occlusal contacts quantification and the validity of digital occlusal contacts quantification with traditional methods used for occlusal contact determination. Subjects and Methods: Thirty participants, all of whom were students at the Sahlgrenska Academy, University of Gothenburg in Gothenburg, Sweden, were included in the study. Three different methods were used to evaluate occlusal contacts: (I) a digital examination of the patients’ casts, using the Ortho 3D Models (O3DM) software and measuring the total occlusal contact area in square millimeters (DE); (II) an examination involving the measurement of the total number of occlusal contacts on stone casts mounted in an articulator (AE); and (III) a clinical examination with the measurement of the total number of occlusal contacts with 8 μm-thick articulating foil (CE). Results: The repeated digital measurements (same casts scanned multiple times) showed a significant correlation of 0.85 (p < 0.01), which shows a diagnostic consistency. Furthermore, there was a significant correlation between the results obtained with the DE method and the AE of 0.41 (p < 0.05), and between those acquired with the AE method and the CE of 0.37 (p < 0.05). However, no significant correlation was found between the DE method and the CE method with a correlation coefficient of 0.10 (p > 0.05). Conclusions: Digital casts can be used for quantification of the total occlusal contact area (in mm2) owing to the high reliability of repeated measurements and the strong validity of the method compared to traditionally employed stone cast measurements.

The Role of Intrapartum Ultrasound to Predict Outcome of Delivery

Objective: To predict outcome of delivery by using ultrasound measurements consisting angle of progression, and head perineum distance.Methods: Sixtytwo parturients assigned in cohort prospective study. Ultrasound examination begin with identifying the cephalic position by placement of transducer on suprapubic region. The angle of progression is obtained trans-labially, head perineum distance and cervical dilation trans-perineally. Ultrasound findings of Nuchal cord, caput, moulding, occiput posterior position then compared with conventional findings. Labour is observed, outcomes are grouped into vaginal delivery and cesarean section.Results: Thirty-six women went for vaginal delivery, 26 underwent cesarean section. Independent T-test showed significant differences of the angle of progression (121.11o vs 88.85o) and head perineum distance (5.15 cm vs 7.26 cm) between the two groups. Linear regression test found a negative correlation on how the angle of progression affecting head perineum distance p-value <0.05 , R2 0.684, (r) – 0.827. Cervical dilation measurements both ultrasound and digital examination were assessed with the Bland-Altman reliability test with level of agreement (-1.0 cm) – (1.2 cm). Receiver Operating Characteristic curve showed cut-off value >101o angle of progression predicts vaginal delivery, area under curve 0.902 and positive likelihood ratio 4.4. Kappa reliability testing for nuchal cord, caput, moulding, and occiput posterior are 0.919, 0.938, 0.384, 0.681 respectively.Conclusion: Intrapartum ultrasound able to predict the outcome of delivery, digital examination of cervical dilation is the mainstay of measurement. Ultrasound able to rule out the presence of nuchal cord, caput, and occiput posterior. Keywords: angle of progression, head perineum distance, intrapartum ultrasound. Abstrak Tujuan: Mengetahui besar sudut penurunan kepala dan jarak kepala ke perineum dengan ultrasonografi intrapartum dalam memprediksi luaran persalinan. Metode: Enam puluh dua ibu bersalin dilakukan pemeriksaan ultrasonografi intrapartum. Identifikasi posisi kepala dengan meletakan transduser di suprapubik, sudut penurunan kepala secara translabial, jarak kepala ke perineum dan nilai dilatasi serviks secara transperineal. Lilitan tali pusat, kaput, molase, dan oksiput posterior pada temuan ulstrasonografi dibandingkan dengan hasil pemeriksaan konvensional. Observasi persalinan dilakukan, di kelompokan untuk persalinan pervaginam dan seksio sesarea.Hasil: Didapatkan 36 persalinan pervaginam dan 26 seksio sesarea. Uji – t secara signifikan berbeda, nilai sudut penurunan kepala (121,11o vs 88,85o), jarak kepala ke perineum (5,15 cm vs 7,26 cm) pada kedua kelompok. Uji regresi linier sudut penurunan kepala dan pengaruhnya terhadap jarak kepala ke perineum berkorelasi negatif p <0.05, R2 0.684, (r) – 0.827. Batas kesepakatan nilai dilatasi serviks kedua metode diuji dengan uji reliabilitas Bland-Altman dengan batas kesepakatan sebesar (-1.0) cm – (1.2) cm. Sudut penurunan kepala memprediksi persalinan pervaginam sebesar >101o, uji diagnostik dengan kurva Receiver Operating Characteristic didapatkan area dibawah kurva 0.902, rasio kemungkinan positif 4,4. Uji reliabilitas Kappa lilitan tali pusat, kaput ,molase, dan oksiput posterior berturut-turut (k) = 0.919, 0.938, 0.384, dan 0.681. Kesimpulan: Penggunaan ultrasonografi intrapartum dapat memprediksi luaran persalinan, pemriksaan dalam tetap menjadi pemeriksaan utama dalam menilai dilatasi serviks, ultrasnografi mampu mendeteksi lilitan tali pusat, kaput, dan posisi oksiput posterior.Kata kunci: Jarak kepala ke perineum, sudut penurunan kepala, Ultrasonografi intrapartum.

Unsupervised learning for large-scale corneal topography clustering

Machine learning algorithms have recently shown their precision and potential in many different use cases and fields of medicine. Most of the algorithms used are supervised and need a large quantity of labeled data to achieve high accuracy. Also, most applications of machine learning in medicine are attempts to mimic or exceed human diagnostic capabilities but little work has been done to show the power of these algorithms to help collect and pre-process a large amount of data. In this study we show how unsupervised learning can extract and sort usable data from large unlabeled datasets with minimal human intervention. Our digital examination tools used in clinical practice store such databases and are largely under-exploited. We applied unsupervised algorithms to corneal topography examinations which remains the gold standard test for diagnosis and follow-up of many corneal diseases and refractive surgery screening. We could extract 7019 usable examinations which were automatically sorted in 3 common diagnoses (Normal, Keratoconus and History of Refractive Surgery) from an unlabeled database with an overall accuracy of 96.5%. Similar methods could be used on any form of digital examination database and greatly speed up the data collection process and yield to the elaboration of stronger supervised models.