• 구강회복응용과학지
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• 제20권1호
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• pp.57-70
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• 2004

The significance of occlusion has regained its popularity in dentistry with the introduction of implant therapy. Literature has reported that the clinical success and longevity of dental implants can be achieved by biomechanically controlled occlusion. Occlusal overload is known to be one of the main causes for implant failure. Evidences have suggested that occlusal overload contribute to early implant bone loss as well as deosseointegration of successfully integrated implants. Unlike natural teeth, osseointegrated implants are ankylosed to surrounding bone without the periodontal ligament (PDL) which provides mechanoreceptors as well as shock-absorbing function. Moreover, the crestal bone around dental implants may act as a fulcrum point for lever action when a force (bending moment) is applied, indicating that implants/implant prosthesis could be more susceptible to crestal bone loss by applying force. Hence, it is essential for clinicians to understand inherent differences between teeth and implants and how force, either normal or excessive force, may influence on implants under occlusal loading. The purposes of this paper are to review the importance of implant occlusion, to establish the optimum implant occlusion with biomechanical rationale, to provide clinical guidelines of implant occlusion and to discuss how to manage complications related to implant occlusion.

• Journal of Oral Medicine and Pain
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• 제19권2호
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• pp.153-168
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• 1994

The aim of the present study was to investigate a relation between occlusal wear area and occlusal contact patterns. For the purpose, occlusal wear area were measured in 58 dental students and in 129 patients with temporomandibular disorders(TMDs) from dental casts. Teeth used in this study were from canine to second molar on both sides in upper arch, totally ten. Occlusal wear area on casts was marked by pencil and photocopies, and then, the area was measured with planimeter. Occlusal relation was clinically examined with regard to Angle's classification, chewing side preference, lateral guidance pattern and bruxing and/or clenching habit. T-Scan, electronic occlusal contact analyzer, was used to record occlusal contact number, contact force, contact time and occlusal balance that is TLR(total left-right statistics) during tooth contact. All measurement were repeated 3 times and the average value was used for data processing. The obtained results were as follows : 1. Mean value of occlusal wear area did not differ significantly between dental students and patients. 2. There ws not significant difference in wear area between chewing side and non-chewing side in both groups. 3. Occlusal wear area was significantly increased with age in both groups. 4. Three subgroups divided by Angle's classification did not show any difference in occlusal wear area among them, but three subgroups divided by lateral guidance pattern showed slightly significant difference between canine guide subgroup and group function subgroup in patients. Occlusal wear ares\a in group function subgroup wear larger than canine guide subgroup. 5. Mean value of wear area in patients with bruxing and/or clenching habit did not differ from those in patients without such habit. 6. Correlationship among items related to occlusal contact pattern were highly consistent and significant in dental students and only one item significantly correlated with occlusal wear area was tooth contact time.

• 구강회복응용과학지
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• 제19권1호
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• pp.7-15
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• 2003

This study used FEM(Finite Element method) based on micro-CT images to see the effects of occlusal force distribution with varying bone density and structure. the mandibular premolar region from human cadaver, thickness of 10mm was imaged using micro-CT. the cross sectional images were taken every $10{\mu}m$. these were reconstructed and the longitudinal image at the mid point of mesiodistal of the speciman was obtained for the specimen for the FEM. The stress disribution produced by a vertical force at 100N and 100N horizontal were analyzed by MSC Nastran FEM Package. according to the result of this study the occlusal force distribution depends on the structure of cancellus bone and for further information on the occlusal force distribution on the tooth and the surrounding structure requires further studies on cancellus bone structure. CEJ of all model show the highest peak and region whice meet teeth and bone show second high peak. Original model and cortical bone add model show different stress distribution. Stress distribution changed according to bone structures and densities.

• 대한치과교정학회지
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• 제21권1호
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• pp.185-195
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• 1991

This study was undertaken to grope the correlation of the maximal bite force and tooth-craniofacial structure. The maximal bite force of 76 adult male, aged 18-28 (mean aged: $23.4{\pm}2.2$) years, was estimated and cephalometric headplates were measured, tabulated and statistically analyzed. The results were as follows. 1. 59.61kg of bite force in first molar, 45.38kg in premolar and 17.10kg in central incisor were arranged. 2. The bite force was negatively correlated to genial angle, mandibular plane angle, the angle between occlusal plane and mandibular plane, the angle between palatal plane and mandibular plane, and positively correlated to posterior height of face, length of mandibular body, length of ramus, facial depth in craniofacial structure. 3. The group with strong bite force showed small genial angle, mandibular plane angle, the angle between occlusal plane and mandibular plane, the angle between palatal plane and mandibular plane, and long posterior height of face, length of mandibular body, length of ramus, facial depth. So they manifested the tendency to brachycephalic pattern, on the other hand, the group with weak bite force manifested the tendency to dolichocephalic pattern. 4. There is no correlationships between bite force and mesial inclination of premolar axis in this subject. 5. It is considered bite force have an effect upon craniofacial pattern, especially upon the lower face.

• 대한치과보철학회지
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• 제36권1호
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• pp.18-25
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• 1998

The purpose of this study was to determine how to use soft relining material by observing an amount of denture displacement according to the different base area of residual ridge and thickness of soft relining material under masticatory force. Stone models that simulated residual ridge were made with different amount of denture base area and denture was fabricated by conventional heat curing resin with usual manner on the model and relined by silicone type soft relining material with different thickness. Specimen was examined the amount of denture displacement by Instron within range of normal occlusal force. The results were as following : 1. The increasing rate of denture displacement was higher than that of soft relining material thickness. 2. The amount of denture displacement decreased 1.7 times when base area became double at same thickness of soft relining material 3. The increasing rate of denture displacement was higher than that of occlusal force

• 대한치과보철학회지
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• 제27권2호
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• pp.271-277
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• 1989

The purpose of this preliminary report was to describe the operating procedure of T-scan system and to identify the location, timing and force of occlusal contact in patient with normal occlusion using computerized T-scan system. From the preliminary observation , the author obtained the following results. 1. T-scan system displayed 2 dimensional and 3 dimensional description of occlusion: contact locations, timing (sequence) and forces of occlusal contacts. 2. The T-scan sensor was the most important part of the T-scan system. 3. The data of T-scan system cannot be stored in computer diskett. 4. The T-scan system is thought to be the most effective system to detect occlusal contacts and can be applied to the followings : occlusal diagnosis, occlusal equilibration, crown and bridge restorative procedures, denture adjustment, implant procedures, splint adjustment, laboratory procedures, periodontal treatment, orthodontics, TMJ treatment and patient education etc.

• 대한치과교정학회지
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• 제40권3호
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• pp.176-183
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• 2010

고정식 교정장치를 이용한 교정치료 후 교합의 기능적 변화를 평가하기 위해, 교합력 및 교합접촉면적을 측정하여 단기적인 변화 양상을 확인하고 소구치 발치 여부에 따른 차이를 파악하였다. 고정식 교정장치로 치료를 종료한 18세 에서40세 사이의 성인을 남자군과 여자군으로 분류하고, 각각의 군을 4개의 소구치를 발치한 군과 비발치로 치료한 군으로 세부 분류하였다(남자발치군 16명, 남자비발치군 18명, 여자발치군 19명, 여자비발치군 21명). Dental prescalesystem (Fuji Film Corp., Tokyo, Japan)의 pressure sensitive sheet를 5초간 최대교두감합위에서 최대근력으로 교합하도록 한 뒤 CCD camera를 이용해 교합력과 교합면적을 측정하였다. 고정식 교정장치를 제거하고 고정식유지장치를 붙인 직후, 교정장치 제거 1주일, 1개월, 3개월, 6개월, 1년 뒤에 각각 측정하여 비교하였다. 모든 군에서 교정장치 제거 후 1년간의 유지기간 동안 교합력과 교합면적은 점진적으로 증가하였다 (p < 0.05). 모든 측정 시기에서 남자군은 여자군보다 높은 교합력과 교합면적을 보였으며 (p < 0.05), 남자, 여자군 모두에서 발치군과 비발치군 사이에는 교합력 및 교합면적에서 통계적으로 유의한 차이가 관찰되지 않았다 (p > 0.05). 본 연구를 통해 교정치료 후 1년간의 유지기간 동안 교합이 기능적으로 향상됨을 파악하였고, 소구치 발치로 인한 교합의 기능적 저하는 없을 것이라 추측할 수 있었다.

• The Journal of Advanced Prosthodontics
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• 제12권2호
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• pp.49-54
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• 2020

PURPOSE. The purpose of this study was to compare the performance of Accura to that of the T-scan for indicating occlusal contacts. MATERIALS AND METHODS. Twenty-four subjects were selected. Their maxillary dental casts were scanned with a model scanner. The Stereolithography files of the casts were positioned to align with the occlusal plane. Occlusal surfaces of every tooth were divided into three to six anatomic regions. T-scan and Accura recordings were made during two masticatory cycles. The T-scan and Accura images were captured at the maximum bite force and overlapped to the cast. Photographs of interocclusal records were used as the reference during overlap. The occlusal contacts were counted to compare the T-scan and Accura. McNemar's test was used for statistical significance and the corresponding P-values were calculated from a chi-square distribution with one degree of freedom. The accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Accura were calculated relative to the T-scan values as a control. RESULTS. No statistical differences (P>.05) were found between the T-scan and Accura methods. The accuracy of Accura was 75.8%, sensitivity was 82.1%, specificity was 60.1%, PPV was 82.9%, and NPV was 60.1%. CONCLUSION. Accura could be another possible option as a computerized occlusal analysis system for indicating occlusal contacts at maximum intercuspation.

• 대한치과보철학회지
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• 제61권2호
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• pp.160-178
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• 2023

보철 치료 시 교합관계의 진단과 분석은 중요한 요소 중 하나이다. 치료 시행 전 면밀한 교합분석 및 평가가 선행되어 안정적인 악간 관계를 회복시켜 주어야 하며, 치료 과정 및 정기 검진 시에도 이에 대한 평가는 필수적이다. 최근, 치과용 기기와 디지털 처리 방식의 발달로 환자의 교합관계를 기록할 수 있는 새로운 정량적 분석 방법들이 소개되고 있다. 그 중 T-Scan Novus (Tekscan Inc., S. Boston, MA, USA)는 압력측정센서를 이용하여 상하악 치아의 초기접촉점과 교합접촉점의 상대적인 강도를 나타내며 치아의 교합접촉 시간, 교합력의 전후방, 좌우균형을 비교할 수 있다. Dental prescale II (GC Co., Tokyo, Japan)는 압력감지필름을 이용하여 교합접촉점을 스캔하여 접촉점의 밀도를 분석하는 방법으로 최대한 자연스러운 교합상태 치열의 교합력 분포와 강도를 측정할 수 있다. 환자의 치아 상실 부위와 범위에 따라 4-unit 고정성 국소의치, 가철성 국소의치, 총의치, 완전구강회복술을 시행하였다. 적절한 교합 분석을 위해, 초진, 각 치료 단계, 치료 직후 및 정기검진 시의 환자의 교합을 T-Scan Novus와 Dental prescale II를 이용하여 정량적으로 비교, 평가하였다. 보철수복 치료과정에서 교합 분석에 대한 이해도를 제고할 수 있었고, 기능 및 심미적으로 환자와 술자 모두 만족할 만한 결과를 얻었기에 이를 보고하고자 한다.

• Journal of Oral Medicine and Pain
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• 제13권1호
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• pp.43-52
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• 1988

The author studied masticatory muscle activity and bite force in normal persons without Temporomandibular Disorders(TMD) signs and symptoms, The number of subjects was 15, and the age of them was from 22 to 25 years. Electromyography was used to record the muscle activity in tapping and clenching movement with or without occlusal splint. 3 splints were made from 3 different mandibular position, that if, centric occlusion position, Rocabado's mandibular rest position, Dawson's centric relation position. The thickness of splint was 3.0-3.5㎜ at molar region. The muscle examined were Masseter and Anterior Temporalis attached with surface electrodes and the device used to measure the EMG level was Bioelectric processor Model EM2. After recording the EMG, the author measured the bite force level in clenching movement with bite force meter Model MPM-3000 in the dame position used in the EMG experiment. The obtained results were as follow : 1. With occlusal splints insetion, the amount of decreased muscle activity in Anterior Temporalis was more than those in Masseter. 2. In the three maxillomandibular relationships with occlusal splints, Masseter showed slightly increased level of muscle in centric occlusion but Ant. Temporalis showed decreased level of muscle activity reversely in that position. 3. Muscle activities between Rocabado's rest position and Dawson's centric relation position were generally similar whatever the muscles or the movements the author examined. 4. Bite force in clenching movement increased with splints insertion, especially with the splint registered in centric occlusion position.