• The korean journal of orthodontics
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• v.40 no.3
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• pp.176-183
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• 2010

Objective: This study was performed to evaluate functional changes of occlusion after orthodontic treatment by measuring the occlusal force (OcFr) and occlusal contact area (OcAr), and to compare OcFr and OcAr change according to premolar extractions. Methods: Data were obtained from 74 patients who had finished orthodontic treatment using fixed appliance aged between 18 and 40 years. Subjects were divided into groups who had four premolars extractions or non-extraction (Male extraction-16, Male nonextraction-18, Female extraction-19, Female nonextraction-21). All subjects were asked to bite pressure-sensitive sheets into maximum intercuspation with maximum bite force, and OcFr and OcAr were evaluated by measuring the sheet with a CCD camera. Records were taken right after debonding, 1 week, 1 month, 3 months, 6 months and 1 year after debonding. Results: OcFr and OcAr increased gradually in all groups during the 1 year retention period (p < 0.05). Male groups showed higher OcFr and OcAr than female groups throughout the retention periods (p < 0.05). There were no statistically significant differences of OcFr and OcAr between extraction and non-extraction groups in both males and females (p > 0.05). Conclusions: Occlusion was improved functionally throughout the 1 year retention, and premolar extraction did not induce a decline in the functional aspect of occlusion.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.4
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• pp.328-334
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• 2020

Clinical remounting of complete denture is performed to refine occlusal harmony in maxillo-mandibular relation. It has been reported that patients who used adjusted dentures with clinical remounting felt less complications such as pain and discomfort in mastication. The purpose of this study was to assess effects of clinical remounting with case series. Seven patients with existing complete prosthesis were included. Clinical remounting procedure was done through interocclusal relation recording. In addition, occlusal force was measured with pressure indicating sensor and occlusal contact areas were evaluated with photo occlusion analysis. Occlusal contact areas of prosthesis were enlarged, while bite pressure was not increased. Hit and slide phenomenon of prosthesis was reduced concurrently. Clinical remounting procedure improved denture stability and increased occlusal contact area. Therefore, clinical remounting should be considered.

• The korean journal of orthodontics
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• v.52 no.3
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• pp.172-181
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• 2022

Objective: The objectives of this study were to compare the time-dependent changes in occlusal contact area (OCA) and bite force (BF) of the deviated and non-deviated sides in mandibular prognathic patients with mandibular asymmetry before and after orthognathic surgery and investigate the factors associated with the changes in OCA and BF on each side. Methods: The sample consisted of 67 patients (33 men and 34 women; age range 15-36 years) with facial asymmetry who underwent 2-jaw orthognathic surgery. OCA and BF were taken before presurgical orthodontic treatment, within 1 month before surgery, and 1 month, 3 months, 6 months, 1 year, and 2 years after surgery. OCA and BF were measured using the Dental Prescale System. Results: The OCA and BF decreased gradually before surgery and increased after surgery on both sides. The OCA and BF were significantly greater on the deviated side than on the non-deviated side before surgery, and there was no difference after surgery. According to the linear mixed-effect model, only the changes in the mandibular plane angle had a significant effect on BF (p < 0.05). Conclusions: There was a difference in the amount of the OCA and BF between the deviated and non-deviated sides before surgery. The change in mandibular plane angle affects the change, especially on the non-deviated side, during the observation period.

• 대한치과보철학회:학술대회논문집
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• 2003.04a
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• pp.101-101
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• 2003

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.1
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• pp.27-33
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• 2014

Purpose: The purpose of this study was to investigate the food impaction between implant prostheses and adjacent natural teeth. Materials and methods: For this study, 51 patients with food impaction were selected and investigated mobility, tightness of contact area, gingival index, plaque index, attachment loss, alveolar bone level, proximal caries, marginal ridge distance and occlusal relationships. Results: Food impaction was found in the upper teeth (60.7%) more than the lower teeth (39.2%). Food impaction was occurred on mesial side of implant prostheses (86.2%) more than distal side (13.7%). Food impaction was mostly found in loose or open contact area (94.2%). Food impaction was frequent on stepped relationship between implant and adjacent teeth. Conclusion: Treatment plan should include proper adjacent and antagonistic occlusal plane and occlusal surface, to prevent food impaction, and the plan should include less adjacent tooth mobility with proper tightness between implant prostheses and adjacent teeth.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.4
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• pp.222-228
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• 2023

Attrition is the loss of tooth hard tissue due to contact between teeth, and in severe cases, dentin is exposed, accompanied by selective corrosion and excessive wear of teeth, which is called cupping. If these lesions are left untreated, the size of the lesion gradually increases, breaking the unsupported enamel, resulting in a decrease in aesthetics and chewing function. In this case report, patients with cupping and enamel fracture due to severe attrition were directly restored using a resin with soft properties containing organic fillers. In the follow-up observation six years later, most of the filling of the occlusal surface was eliminated, but the filling on the buccal surfaces remained relatively intact, and it was confirmed that this type of resin was suitable for the area where the occlusal force was relatively weak rather than the area where the occlusal force was greatly applied.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.3
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• pp.157-170
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• 2021

Loss of posterior bite support might cause unstable occlusal relationship and when the mandible slides forward in the centric or habitual occlusion, excessive load is applied to the anterior region followed by causing the occlusal plane to collapse or leading to a decrease in occlusal vertical dimension. In addition, disorder of temporomandibular joint function may occur. The inter-dental arch discrepancy causes a mismatch in the vertical and horizontal overlap of the anterior and posterior regions. The deep bite in the anterior region and the scissor bite in the posterior region cause unstable occlusal contact and insufficient occlusal contact area. This report was to rehabilitate a patient with above-mentioned complex problems. Physiologic adaptation to increased vertical dimension and new occlusal plane were evaluated using provisional prostheses, and definitive prostheses was fabricated using cross-mounting technique. Stable occlusion, harmonious teeth overlap and adequate occlusal plane were established, so functionally and aesthetically satisfactory results are obtained.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.1
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• pp.69-78
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• 2007

This study was performed to compare the stress distribution pattern in the crestal cortical bone and cancellous bone using 3-dimensional finite element stress analysis when 2 different Young's modulus(high modulus, model 1; low modulus, model 2) of cancellous bone was assumed. For the analysis, a finite element model was designed to have two square-threaded implants fused together and located at first and second molar area. Stress distribution was observed when vertical load of 200N was applied at several points on the occlusal surfaces of the implants, including central fossa, points 1.5mm, 2mm, 3mm and 3.5mm buccally away from central fossa. The results were as follows; 1. In both model, the maximum Von-Mises stress in the crestal cortical bone was greater when the load was applied at the central point, points 1.5mm and 2mm buccally away from central fossa than other cases. 2. In the cortical bone around first and second molar, model 2 showed greater Von-Mises stress than model 1. It is concluded that when the occlusal contact is afforded, the distribution of stress varies depending on the density of cancellous bone and the location of loading. More favorable stress distribution is expected when the contact load is applied within the diameter of fixtures.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.3
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• pp.328-342
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• 1999

This study was performed to investigate the factors related to tooth wear. For this study, 78 patients with temporomandibular disorders and 76 dental students without any signs and symptoms of temporomandibular disorders were selected as the patients group and as the normal group, respectively. Preferred chewing side, Angle's classification, lateral guidance pattern, head and shoulder posture were observed clinically. Electromyographic activity of anterior temporalis and masseter muscle were recorded with $BioEMG^{(R)}$ and occlusal status were recorded with $T-Scan^{(R)}$. Wear facet area of each tooth was measured from working model of upper arch corresponding to the occlusal status from T-Scan. Wear facet area were measured with planimeter in $mm^2$. Total area were divided into incisal, canine, posterior tooth area. Anterior wearfacet area was incisor area plus canine area, and unilateral area was anterior area plus posterior area. The data collected were analyzed by SAS statistical program and the results of this study were as follows: 1. There was no significant difference between the two groups in total werafacet area, and male subjects showed tendency to have larger area in the normal group but female subjects showed tendency vice versa. 2. There was no significant difference related to preferred chewing side and Angle's classification, however some difference was observed by lateral guidance pattern. Anterior wear facet area in subjects of canine guidance was the largest in the three subgroups. 3. Subjects with head tilting to right side had larger posterior and total area, and subjects with higher shoulder in right side had larger canine and anterior area than any other subgrous. 4. Electromyographic activity of masseter muscle was more correlated with wear facet area than anterior temporalis muscle, and tooth contact number and force were significantly correlated with wear facet area, but the most important factor affecting tooth attrition was age.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.245-254
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• 2006

While orofacial pain or various dental factors are generally considered as the primary cause of unilateral chewing tendency, there exist several studies indicating that dental factors did not affect the preferred chewing side. The aim of this study was to examine difference of occlusal scheme between the subjects with and without chewing side preference. The difference between the chewing and non-chewing sides in the unilateral chewing group was investigated as well. Computerized, T-Scan II system was used for occlusal analysis. 20 subjects for the unilateral chewing group (mean age of $25.25{\pm}2.84$ years) and 20 subjects for the bilateral chewing group (mean age of $27.00{\pm}5.07$ years) were selected by a questionnaire on presence or absence of chewing side preference and those with occlusal problem or pain and/or dysfunction of jaw were excluded. T-Scan recordings were obtained during maximum intercuspation and excursion movement. The number of contact points, relative occlusal force ratio between right and left sides, tooth sliding area and elapsed time throughout the maximum intercuspation were calculated. Elapsed time for excursion was also investigated. The results of this study shows that the unilateral chewing group had the smaller average tooth contact areas compared with those of the bilateral group (p<0.005). In the unilateral chewing group, the contact areas of non-chewing side are smaller than those of chewing side (p<0.005). The contact areas on their preferred sides were not significantly different with those of right or left side of the subjects without chewing side preference. There was no significant difference in the elapsed time during maximum intercuspation and lateral excursion, the sliding areas and relative of right-to-left occlusal force ratio between the two groups. From the results of this study, it is likely that individuals prefer chewing on the side with more contact areas for efficient chewing.