• The Journal of Advanced Prosthodontics
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• v.13 no.4
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• pp.216-225
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• 2021

PURPOSE. The aim of this study is to evaluate the effects of canine guidance occlusion and group function occlusion on the degree of stress to the bone, implants, abutments, and crowns using finite element analysis (FEA). MATERIALS AND METHODS. This study included the implant-prosthesis system of a three-unit bridge made of monolithic zirconia and hybrid abutments. Three-dimensional (3D) models of a bone-level implant system and a titanium base abutment were created using the original implant components. Two titanium implants, measuring 4 × 11 mm each, were selected. The loads were applied in two oblique directions of 15° and 30° under two occlusal movement conditions. In the canine guidance condition, loads (100 N) were applied to the canine crown only. In the group function condition, loads were applied to all three teeth. In this loading, a force of 100 N was applied to the canine, and 200-N forces were applied to each premolar. The stress distribution among all the components of the implant-bridge system was assessed using ANSYS SpaceClaim 2020 R2 software and finite element analysis. RESULTS. Maximum stress was found in the group function occlusion. The maximum stress increased with an increase in the angle of occlusal force. CONCLUSION. The canine guidance occlusion with monolithic zirconia crown materials is promising for implant-supported prostheses in the canine and premolar areas.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.301-312
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• 2022

In an extensive oral rehabilitation, determining a proper occlusal vertical dimension is a critical step and the starting point for successful treatment. Since changing the occlusal vertical dimension could be time-consuming, financially challenging, and physically demanding for both clinicians and patients, multi-faceted analysis and careful consideration are essential in the diagnosis and further treatment process. The purpose of this narrative review is to discuss the occlusal vertical dimension and its current issues, and to summarize previous methods of evaluating occlusal vertical dimension to propose clinical guidance for determining a viable occlusal vertical dimension for full-mouth rehabilitation.

• The korean journal of orthodontics
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• v.18 no.1 s.25
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• pp.7-24
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• 1988

The stable occlusion in function is thought as important as the esthetics in form, in order to preserve the healthy oral condition. The stable occlusion requires the harmony between the condylar guidance factors and the anterior guidance factors. The aim of this study was to evaluate the quantitative relationship between the condylar guidance factors and the anterior guidance factors, estimating statistically the measurement of the condylar paths by Pantronic and those of the anterior guidance factors, craniofacial morphology by roentgenocephalometry in 46 relatively good functional occlusion. The results of this study were as follows. 1. The measurements of the protrusive condylar path inclinations were $36.41^{\circ}$ in the right, $35.63^{\circ}$ in the left, $36.28^{\circ}$ in the mean. The measurements of Fisher's angles were $8.17^{\circ}$ in the right, $6.43^{\circ}$ in the left, $6.87^{\circ}$ in the mean. 2. The anterior facial height and the lower anterior facial height made a negative correlation with the protrusive condylar path inclination. 3. The articular eminence angle relative to the artificial articulator plane showed a positive correlation with the maximum protrusive condylar path. 4. SNA and SNB made a negative correlation with the articular eminence angle, and AAP-GoMe, AAP-DcGn, the facial height ratio had a positive correlation with the articular eminence angle. 5. The angulation of maxillary incisor lingual slope, overbite and the ratio of overbite to overiet showed a positive correlation with the articular eminence angle. 6. The angulation of maxillary incisor lingual slope , overbite, and the ratio of overbite to overjet made a positive correlation with the inclination of occlusal plane, functional occlusal plane. 7. Overbite and the ratio of overbite to overjet had a positive correlation with the angulation of maxillary incisor lingual slope. 8. The anterior guidance factors were more influenced by the mean protrusive condylar path inclination and the maximum Fisher's angle, and the regression equations of those were made.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.59-68
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• 2013

The objective of this study was to analyze occlusal contact pattern of 33 young adult males with normal occlusion during lateral excursion using T-scan III system which can measure the dynamic occlusion. Occlusal contact patterns were examined and categorized in non-working side disclusion point(more functionally acceptable position) not canine-to-canine position. Disclusion time, occlusal force, and occlusal force distribution ratio of upper canine at disclusion point during lateral excursion movement was also measured and compared among the groups divided according to contact patterns. The results showed that group function was clearly more dominant than canine guidance and other occlusal contact patterns different with existing patterns were found. There were significantly difference between groups in variables of T-scan measurement. T-scan III system is effective tools to analyze and evaluate occlusal contact patterns, disclusion time, occlusal force, and occlusal force distribution ratio of upper canine at disclusion point.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.320-329
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• 2022

Physiological wear of occlusal surface is inevitable throughout the lifetime, and considered to be normal. Pathologic wear, however, may cause fatal damage to the occlusal surface and destroy esthetics and proper anterior guidance. In such cases, rehabilitation of occlusal wear should be followed by thorough evaluation and diagnosis. In this present case, severe occlusal wear was found in the labial surfaces of mandibular anterior teeth and palatal surfaces of maxillary anterior teeth. Occlusal vertical dimension was evaluated and decided to be regained due to insufficient amount of restorative space. After determining new occlusal vertical dimension, diagnostic wax-up is usually performed to continue prosthodontic treatment. In this case with collapsed occlusion and loss of occlusal vertical dimension, conventional diagnostic wax-up was replaced with various digital devices. Diagnostic wax-up was digitally performed in the software and provisional prosthesis was fabricated with digital tools. With verification with provisional prosthesis, the entire dentition was rehabilitated with newly set occlusal vertical dimension and proper anterior guidance.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.4
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• pp.463-476
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• 2010

Inadequate or unstable posterior support cause extrusion of antagonistic teeth and overloading of remaining teeth. Extrusion of antagonistic teeth result in collapsed occlusal plane and decreased prosthetic space. Also, overloading of remaining teeth increase occlusal wear or anterior extrusion of anterior teeth, which is resulting in loss of anterior guidance, disharmony of occlusion and decreased prosthetic space. In this case, careful evaluation of OVD(occlusal vertical dimension) is the general first trial to regain appropriate function and esthetics. Simultaneously, adequate anterior guidance and harmonious occlusal plane should be established in the repeatable reference position of the mandible. We report this case because severely worn dentition achieved functional and esthetic results from full mouth rehabilitation with increased vertical dimension and use of centric relation.

• Journal of Korean Dental Science
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• v.14 no.1
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• pp.26-31
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• 2021

Purpose: This study aimed to find a correlation between the occlusal plane and two reference planes that are frequently used in semi-adjustable articulators. Materials and Methods: Sixty-two males and fifty females with normal articulation were recruited and the lateral cephalograms of these patients were taken. The angles between the Frankfort horizontal (FH) and the occlusal planes, the angles between the gnathologic and the occlusal planes, and the angles between the FH and gnathologic planes were measured on the lateral cephalograms. Result: The mean angles between the FH and the occlusal planes was 8.29°±3.62°, with 8.88°±3.09° and 7.63°±4.10° for male and female patients, respectively. The mean angles between the gnathologic and the occlusal planes was 2.77°±3.62°, and the angle between the FH and the gnathologic planes was 5.52°±3.62°. No significant differences were found in the measured angles between the male and female patients (P>0.05). Conclusion: Different guidance angles may be applied to articulators for prosthodontic restoration, depending on the reference planes that the articulators use.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.199-207
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• 2013

Purpose: The importance of occlusal contacts of the natural dentition for durability of teeth, mandibular stabilization, and restorative dentistry is well known. The purpose of this study is to analyze the occlusal contact and guidance pattern of Koreans by evaluating the static occlusion on maximal intercuspal position and measuring dynamic occlusion during straight protrusion. Materials and methods: The occlusal contacts at maximal interincisal position and the occlusal guidance pattern during straight protrusion of 29 subjects were recorded with shimstock foil (Whaledent, Langenau, Germany), T-Scan III (Tekscan Inc., Boston, MA, USA), polyvinylsiloxane registration material (Genie Bite, Sultan Healthcare, Hackensack, NJ, USA) and compared. Occlusal registration procedures were repeated 3 times. The position was fixed to an upright position and the head position was fixed with the Frankfurt horizontal plane paralleling the horizontal plane. Fisher's Exact Test (R-General Public License, ver. 2.14.1) and Pearson's Test were used to assess the significance level of the differences between the experimental groups (${\alpha}=.05$). Results: When using shimstock foil, T-Scan III system, and polyvinylsiloxane registration material, most of the patients showed contact on anterior, premolar, and molar teeth during maximal intercuspal position. Approximately 51% of maximal intercuspal position showed anterior contact using shimstock foil. When examining the protrusive movement using shimstock foil and T-Scan III system, guidance pattern with the central incisor was the most common. Conclusion: During maximal intercuspal position, there were cases in which not all of the teeth showed occlusal contact. During mandibular protrusive movements, one or more maxillary central incisors frequently joined in straight protrusion and the posterior teeth were disoccluded. Therefore, the anterior teeth protect the posterior teeth, and vice versa. Thus, mutually protected occlusion should be applied when reconstructing occlusion.

• Journal of Oral Medicine and Pain
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• v.13 no.1
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• pp.85-93
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• 1988

The author studied maximum clenching EMG activities of temporalis anterior and masseter muscle during canine guidance and centric occlusion. It was performed before and after anesthesia of maxillary and mandibular canines. The 22 normal subjects (15 males and 7 females) who had healthy maxillary and mandibular canines were selected. Their occlusal contact scheme was canine guidance during movement and they did not have temporomandibular disorder. The results were as follows : 1. The maximum clenching EMG activities of temporalis anterior and masseter muscle during guidance were less than those during centric occlusion. 2. After left maxillary and mandibular canines were anesthetized with 2% lidocanine with 1:100,000 epinephrine, the maximum clenching EMG acivities of temporalis anterior and masseter muscle during left canine guidance were greater than those before anesthesia of left maxillary and mandibular canines(p<0.01) 3. The maximum clenching EMG activities of temporalis anterior and masseter muscle during right guidance were not significantly different between before and after anesthesia of left maxillary and mandibular canines(p>0.05).

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.405-415
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• 2019

Excessive tooth wear can cause irreversible damage to the occlusal surface and can alter the anterior occlusal relationship by destroying the structure of the anterior teeth needed for esthetics and proper anterior guidance. The anterior deep bite is not a morbid occlusion by itself, but it may cause problems such as soft tissue trauma, opposing tooth eruption, tooth wear, and occlusal trauma if there are no stable occlusal contacts between the lower incisal edge against its upper lingual surface. The most important goal of treatment is to form stable occlusal contact in centric relation. In this case report, patients with decrease in vertical dimension and anterior deep bite due to maxillary posterior tooth loss and excessive tooth wear were treated full mouth rehabilitation with increased vertical dimension to regain the space for restoration and improve anterior occlusal relationship and esthetics. The functional and aesthetic problems of the patient could be solved by the equal intensity contact of all the teeth in centic relation (CR), anterior guidance in harmony with the functional movement, and restoration of the wear surface beyond the enamel range.