Analyzing center of rotation during opening and closing movements of the mandible using computer simulations

Ahn, Sug-Joon; Tsou, Ling; Sánchez, C. Antonio; Fels, Sidney; Kwon, Ho-Beom

doi:10.1016/j.jbiomech.2014.12.041

Cited by 20 publications

(20 citation statements)

References 51 publications

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“…2. This suggests that the point where pure rotation ends and rotation plus translation starts is about 8 mm of interincisal distance and this is consistent with previous studies [24] that stated that the translation and rotation occurred simultaneously from early opening.…”

Section: Discussionsupporting

confidence: 92%

“…The amount of vertical opening used in different devices is given in millimeters (range 1–14 mm) [8, 34, 38–40, 42–44]. Although studies have shown that appliances with both an increased [38, 48, 49] or minimal [49, 50] vertical dimension are effective, physiologic evidence suggest that the vertical dimension should be kept to a minimum to optimize treatment outcome [24]. Our results help to understand the findings of Piskin where the most increase happened in the pharynx with a splint having the least vertical occlusion with the highest degree of protrussion [17].…”

Section: Discussionmentioning

confidence: 99%

“…As Posselt mentions [23] the posterior curve represents the motion limit of the mandible in its most posterior location. This occurs as a rotational movement of the mandible in its hinge in the center of the condyles [24]. This movement is represented as an arch with its center in the condyle (landmark Co) and having the curve pass through the inferior incisor through the line connecting the condyle and inferior incisor (Co-II) (Fig.…”

Section: Methodsmentioning

confidence: 99%

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Antero-posterior mandibular position at different vertical levels for mandibular advancing device design

et al. 2019

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Introduction Mandibular Advancement Devices (MAD) have been reported to be an alternative treatment to CPAP in moderate to severe obstructive sleep apnea (OSA) cases. The design of MAD has a major influence on its success rate on the patient, and design features that have an influence on efficacy, tolerance, and compliance. The aim of this study was to determine the range of mandibular protrusion at different vertical points; 2, 5, 8 and 11 mm in a young adult population. Methods Fifty two students aged 19 to 23 years (mean 21.3 ± 1.7; 29 females and 23 males), with full permanent dentition participated in the study. The absolute range of maximal mandibular protrusion and retrusion was measured (mm) with the use of the George Gauge. Descriptive statistics, ANOVA and paired t-test using SPSS were used. Results Range of mandibular advancement was possible to be determined for the 4 levels of vertical opening with the gauges: 2 mm fork mean mandibular advance 13,10 mm ± 0.604; 5 mm mean 11.98 mm ± 1.075; 8 mm mean 11.20 mm ± 1.369; 11 mm mean 9.87 mm ± 1.886. No significant differences were found between class I, II, and III. Conclusions There is an impact of increased inter-incisal distance of effective mandibular protrusion when constructing a MAD. As vertical dimension increases the mandible rotates posteriorly and places itself in a more retrusive location, and the range of mandibular advancement reduces (0.3 mm for every 1 mm of vertical increase).

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Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Antero-posterior mandibular position at different vertical levels for mandibular advancing device design

et al. 2019

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“…Additionally, there is to date an ongoing discussion about the relevance and applicability of the hinge axis concept. Firstly, there is no consensus at all, if the mandible performs a pure rotation during the first phase of mouth opening or last phase of mouth closing (Ahn et al 2015;Ferrario et al 1996;Gallo et al 2008;Hellsing et al 1995;Lindauer 1995;Nagy et al 2002;Palla et al 2003;Thieme et al 2006;Torii 1989). If there would not be a pure rotation, it is debatable, which "rotation axis" instead…”

Section: Discussionmentioning

confidence: 99%

Is it possible to detect a true rotation axis of the temporomandibular joint with common pantographic methods? A fundamental kinematic analysis

Mehl

2020

Computer Methods in Biomechanics and Biomedical Engineering

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The location of the terminal hinge axis of the temporomandibular joint is still a very widespread procedure in dentistry in order to replicate the movement in various articulator devices. Especially pantographic methods are claimed to provide accurate measurements and, additionally, are seen to be able to separate a pure rotation of the joint from a movement with an arbitrary combined shift and rotation. In the latter application, these methods were used in a lot of studies as a reference standard. The aim of this study was to analyze, whether common pantographic methods in general are able to distinguish between a pure rotation and a movement with rotational and translational portions. The mathematical proof of this analysis was done with theoretical kinematic considerations and compared with computer simulations. The results show for the first time that there exist combinations of rotational and translational movements of the temporomandibular joint which cannot be separated from pure rotational movements using actual pantographic methods. Even more, the consequence is a shifted location of the (combined) finite center (axis) of rotation in comparison to the true center (axis) of rotation: in case of a translational portion of only 1 mm, this is a displacement of around ±6 mm and, in case of 2 mm translation, a displacement of ±12 mm. This finding necessitates a critical reinterpretation of former studies using pantographic methods as a reference standard. Further, under some circumstances it may also affect the applicability of articulator concepts and the interpretation of functional signs.

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“…As a result of which, the concept of ball (condyle) and socket (glenoid fossa) articulating components have been largely favored in both stock and custom-fitted alloplastic TMJs [8,21]. In addition, eliminating translational joint movement, the ball and socket TMJ design is routinely fabricated with a short condylar component and thick glenoid fossa component, in order to match with the low center of rotation of the natural joint [21,28]. While this may sound practical in clinical scenarios involving bilateral TMJ replacement, unilateral TMJ replacement with currently available alloplastic joint prostheses, could reportedly increase stresses at the condyle and disc articulating surfaces [29].…”

Section: Discussionmentioning

confidence: 99%

In Vitro Biomechanical Simulation Testing of Custom Fabricated Temporomandibular Joint Parts Made of Electron Beam Melted Titanium, Zirconia, and Poly-Methyl Methacrylate

et al. 2019

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Total alloplastic temporomandibular joint (TMJ) replacement has become common. This in vitro study aimed to evaluate wear response of custom-fabricated electron beam melted titanium (EBM-Ti), zirconia, and acrylic TMJ parts when subjected to biomechanical simulation testing. Eighteen prosthetic TMJ parts (condyle, glenoid fossa) were custom-fabricated using computer aided design and manufacturing (CAD/CAM) techniques based on patient's radiographic images. Biomechanical simulation testing of TMJ parts (in different combinations) were done in a modified chewing simulator (108,000 cycles, 1 Hz frequency, 45-60 N compression, strokes-downward 0.15-0.25 s/horizontal, 0.4-0.5 s/upward, 0.25-0.45 s/displacement, 1.5-2.0 mm). Qualitative analysis using scanning electron microscopy revealed wear facets on leading edges of vertical and horizontal simulation strokes. Measurement of pre-test and post-test weights of TMJ parts revealed non-significant reduction in weights due to wear. EBM-Ti and acrylic TMJ glenoid fossae articulating against zirconia condyles during simulation testing had significantly higher wear, evidenced by greater mean reduction in weights. Based on results of this preliminary study, custom-fabricated alloplastic prosthetic TMJ are a viable alternative to stock alloplastic joints. While EBM-Ti and acrylic are suitable biomaterials for custom-fabrication, use of zirconia results in greater wear and requires further studies to optimize their role in customized alloplastic TMJ.

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Analyzing center of rotation during opening and closing movements of the mandible using computer simulations

Cited by 20 publications

References 51 publications

Antero-posterior mandibular position at different vertical levels for mandibular advancing device design

Antero-posterior mandibular position at different vertical levels for mandibular advancing device design

Is it possible to detect a true rotation axis of the temporomandibular joint with common pantographic methods? A fundamental kinematic analysis

In Vitro Biomechanical Simulation Testing of Custom Fabricated Temporomandibular Joint Parts Made of Electron Beam Melted Titanium, Zirconia, and Poly-Methyl Methacrylate

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