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.

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A clinical study on the prognosis of complete denture wearers covering 10 years. Part II. Occlusal contact area.

Nihon Hotetsu Shika Gakkai Zasshi ◽

10.2186/jjps.32.767 ◽

1988 ◽

Vol 32 (4) ◽

pp. 767-773

Author(s):

Nobuaki Shiina ◽

Yoshiaki Okikura ◽

Kaoru Iwase ◽

Hiroaki Hirata ◽

Yutaka Miida ◽

...

Keyword(s):

Clinical Study ◽

Contact Area ◽

Complete Denture ◽

Occlusal Contact

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Parameter Determination and Ion Current Improvement of the Ion Current Sensor Used for Flame Monitoring

Sensors ◽

10.3390/s21030697 ◽

2021 ◽

Vol 21 (3) ◽

pp. 697

Author(s):

Hanqing Xu ◽

Weijun Fan ◽

Jianwei Feng ◽

Peiliang Yan ◽

Shuchan Qi ◽

...

Keyword(s):

Contact Area ◽

High Reliability ◽

Ion Current ◽

Parameter Determination ◽

Current Sensor ◽

Vertical Position ◽

Excitation Voltage ◽

Burner Exit ◽

And Performance ◽

Flame Monitoring

Flame monitoring of industrial combustors with high-reliability sensors is essential to operation security and performance. An ion current flame sensor with a simple structure has great potential to be widely used, but a weak ion current is the critical defect to its reliability. In this study, parameters of the ion current sensor used for monitoring flames on a Bunsen burner are suggested, and a method of further improving the ion current is proposed. Effects of the parameters, including the excitation voltage, electrode area, and electrode radial and vertical positions on the ion current, were investigated. The ion current grew linearly with the excitation voltage. Given that the electrodes were in contact with the flame fronts, the ion current increased with the contact area of the cathode but independent of the contact area of the anode. The smaller electrode radial position resulted in a higher ion current. The ion current was insensitive to the anode vertical position but largely sensitive to the cathode vertical position. Based on the above ion current regularities, the sensor parameters were suggested as follows: The burner served as a cathode and the platinum wire acted as an anode. The excitation voltage, anode radial and vertical positions were 120 V, 0 mm, and 6 mm, respectively. The method of further improving the ion current by adding multiple sheet cathodes near the burner exit was proposed and verified. The results show that the ion current sensor with the suggested parameters could correctly identify the flame state, including the ignition, combustion, and extinction, and the proposed method could significantly improve the magnitude of the ion current.

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Test-Retest-Reliability of Computer-Based Metamorphopsia Measurement in Macular Diseases

Klinische Monatsblätter für Augenheilkunde ◽

10.1055/a-1252-2910 ◽

2020 ◽

Author(s):

Daniela Claessens ◽

Alexander K. Schuster ◽

Ronald V. Krüger ◽

Marian Liegl ◽

Laila Singh ◽

...

Keyword(s):

Macular Edema ◽

Correlation Coefficient ◽

Intraclass Correlation Coefficient ◽

Intraclass Correlation ◽

Measuring Method ◽

Repeated Measurements ◽

Retest Reliability ◽

Macular Diseases ◽

Computer Based ◽

Test Retest Reliability

AbstractIn this study, the test-retest-reliability as one aspect of reliability of metamorphopsia measurements using a computer-based measuring method was determined in patients with macular diseases. Metamorphopsia amplitude, position, and area were quantified using AMD – A Metamorphopsia Detector software (app4eyes GmbH & Co. KG, Germany) in patients with diabetic, myopic, or uveitic macular edema, intermediate or neovascular age-associated macular degeneration, epiretinal membrane, vitelliform maculopathy, Irvine-Gass syndrome, or macular edema due to venous retinal occlusion. The intraclass correlation coefficient (ICC) was calculated in order to determine the repeatability of two repeated measurements and was used as an indicator of the reliability of the measurements. In this study, metamorphopsia measurements were conducted on 36 eyes with macular diseases. Metamorphopsia measurements made using AMD – A Metamorphopsia Detector software were highly reliable and repeatable in patients with maculopathies. The intraclass correlation coefficient of all indices was excellent (0.95 – 0.97). For diseases of the vitreoretinal interface or macular diseases with intra- or subretinal edema, this metamorphopsia measurement represents a supplement for visual function testing in the clinic, as well as in clinical studies.

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Initial Change in the Occlusal Force and Occlusal Contact Area Following Single Molar Implant Restoration

The International Journal of Oral & Maxillofacial Implants ◽

10.11607/jomi.8962 ◽

2021 ◽

Vol 36 (6) ◽

pp. 1139-1146

Author(s):

Ye-Jin Kim ◽

Kyung-Ho Ko ◽

Yoon-Hyuk Huh ◽

Lee-Ra Cho ◽

Chan-Jin Park

Keyword(s):

Contact Area ◽

Occlusal Force ◽

Occlusal Contact ◽

Implant Restoration ◽

Initial Change

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The association between chewing efficiency and occlusal contact area in man

Archives of Oral Biology ◽

10.1016/0003-9969(93)90124-5 ◽

1993 ◽

Vol 38 (7) ◽

pp. 589-596 ◽

Cited By ~ 91

Author(s):

R.J.C. Wilding

Keyword(s):

Contact Area ◽

Occlusal Contact ◽

Chewing Efficiency

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Reliability and validity of short Beck Hopelessness Scale in psychological autopsy study among Chinese rural elderly

International Psychogeriatrics ◽

10.1017/s1041610219001315 ◽

2019 ◽

Vol 32 (4) ◽

pp. 525-531

Author(s):

Zhenyu Ma ◽

Qiuping He ◽

Guanghui Nie ◽

Cunxian Jia ◽

Liang Zhou

Keyword(s):

Correlation Coefficient ◽

High Reliability ◽

Common Factor ◽

Intraclass Correlation ◽

Reliability And Validity ◽

Rural Elderly ◽

Cluster Sampling ◽

Psychological Autopsy ◽

Autopsy Study ◽

Beck Hopelessness Scale

ABSTRACTBackground:Older adults represent the segment of population most exposed to the risk of suicide nearly everywhere in the world. Previous studies showed that hopelessness was an important risk factor for suicide.Aims:This study aimed to evaluate the reliability and validity of the four-item Beck Hopelessness Scale (BHS-4) in psychological autopsy study among Chinese rural elderly.Method:Two-stage stratified cluster sampling method was used to select research sites. Using case-control psychological autopsy study, face-to-face interviews were conducted to collected information.Results:A total of 242 elderly suicide deaths and 242 matched living comparisons were investigated, including 135 males and 107 females for each group. Intraclass Correlation Coefficients (ICC) of the controls were 0.682-0.713. The median score of BHS-4 among suicides was significantly higher than that among controls. The corrected correlation coefficient between items and total score were 0.184-0.723. Cronbach’s Alphas coefficient was 0.834. Only one common factor was precipitated by exploratory factor analysis and the cumulative variance contribution rates were 59.558% for suicides and 52.722% for living controls. The correlation coefficient between hopelessness and depression were 0.481 among suicide death and 0.617 among living controls.Conclusion:The information provided by the informants through psychological autopsy method had high reliability to reflect the actual situation of suicides and controls. BHS-4 has good reliability and validity among Chinese rural elderly suicides. It is suitable for psychological autopsy study among Chinese rural elderly.

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Are occlusal contact area asymmetry and masticatory muscle activity asymmetry related in adults with normal dentition?

CRANIO® ◽

10.1080/08869634.2020.1764270 ◽

2020 ◽

pp. 1-9

Author(s):

Napat Nalamliang ◽

Pattra Sumonsiri ◽

Udom Thongudomporn

Keyword(s):

Contact Area ◽

Muscle Activity ◽

Masticatory Muscle ◽

Occlusal Contact ◽

Masticatory Muscle Activity

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Reproducibility of Toe Pressure Measurements

Journal for Vascular Ultrasound ◽

10.1177/154431670903300301 ◽

2009 ◽

Vol 33 (3) ◽

pp. 129-132 ◽

Cited By ~ 4

Author(s):

Neil Cloete ◽

Clare Kiely ◽

Mary Paula Colgan ◽

Naseem Haider ◽

Sean O'Neill ◽

...

Keyword(s):

Correlation Coefficient ◽

Intraclass Correlation Coefficient ◽

Carotid Artery Disease ◽

Intraclass Correlation ◽

Repeated Measurements ◽

Pressure Measurements ◽

Repeatability Coefficient ◽

Significant Difference ◽

Artery Disease ◽

Toe Pressure

Introduction Ankle/brachial indices are inaccurate in the presence of calcification, and physicians may rely on the measurement of digital pressures. As the population continues to age and with the escalation in type 2 diabetes, the importance of, and reliance on, toe pressure measurements will increase. The aim of this study was to assess the reproducibility of toe pressure measurements in a single vascular laboratory. Methods Repeated ankle/brachial indices and toe pressures were measured in 20 patients (10 with known peripheral vascular disease and 10 with aneurysmal or carotid artery disease but no history of PVD), and 10 control patients. Three measurements were made 48 hours apart. All measurements were made by a single vascular technologist. Reproducibility was assessed by the use of the repeatability coefficient and the intraclass correlation coefficient. Results Ankle/brachial indices ranged from 0.36 to 2.4, toe pressures from 18 mmHg to 173 mmHg, and toe/brachial indices from 0.11 to 1.1. The repeatability coefficient showed no significant difference between measurements ( p > 0.1) and the intraclass correlation coefficient estimates showed high agreement between repeated measurements (0.77–0.99). Bland-Altman plots indicated that the observer variability was equally distributed across the range of pressure measurements. Conclusion These results confirm the intraobserver reproducibility of toe pressure measurements; however, further work is required to demonstrate inter-observer reproducibility.

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