• Imaging Science in Dentistry
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• 제33권1호
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• pp.15-20
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• 2003

Purpose : To investigate the reproducibility of the conventional and digital radiographs to determine the depth of approximal root cavities. Materials and Methods : A total of 80 artificial root cavities were prepared in the approximal surfaces of premolars, maxillary and mandibular molars. Standardized radiographs were taken at the baseline (0° horizontal and 0° vertical) and at a horizontal angulation of 10° in both mesial and distal directions. Radiographic cavity depths were measured by both conventional and digital radiographs. Results: At 0° horizontal angulation, no statistically significant differences could be determined between the results of conventionally and digitally determined radiographic depths with respect to the actual cavity depths in all premolar, maxillary, and mandibular molar groups. All conventional and digital radiographic depths at both 10° mesial and distal angulations showed statistically significant increases in depth compared to the actual cavity depths (p < 0.05), with the exception of digital radiographic depth at 10° mesial angulation for premolars. There were no statistically significant differences between conventional and digital radiographic depths for all groups. Conclusion: The present study suggests that both conventional and digital radiographs provide reproducible assessment of the depth of the approximal root cavity. But horizontal X-ray beam movements are likely to result in increase in radiographic cavity depth.

• Journal of Oral Medicine and Pain
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• 제48권3호
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• pp.112-117
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• 2023

Coronoid process hyperplasia (CPH) of the mandible is a rare condition in which abnormal elongation of the coronoid process leads to chronic mandibular hypomobility. CPH causes impingement or impedance of the coronoid process on the inner surface of the frontal part of the zygomatic bone during mouth opening. The lack of significant symptoms makes the diagnosis difficult. Its etiology remains inconclusive despite several theories being suggested. In this report, three reviewed cases are presented. All three patients visited our clinic with limited mouth opening as the chief complaint. Standard clinical and radiographic examinations were conducted under the initial impression of temporomandibular disorders (TMDs), and restricted jaw movements were confirmed in all cases. The absence of improved signs and symptoms following conservative treatment for TMDs or the indeterminate plain radiographs required the attending clinicians to consider three-dimensional imagery. Computed tomography revealed bilateral coronoid hyperplasia in all cases and impingement on the zygomatic bone in two of the three cases. After concluding that this condition caused the patients' limited mouth opening, the patients were referred to the Department of Oral and Maxillofacial Surgery for possible bilateral coronoidectomy or coronoidotomy. CPH usually presents no symptoms apart from a progressive reduction of mouth opening over time. Diagnosis is often delayed, and patients may undergo unnecessary treatment procedures. Clinicians should be aware of this condition and exercise caution in the differential diagnosis of patients with chronic mandibular hypomobility.

• 대한치과보철학회지
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• 제26권1호
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• pp.113-131
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• 1988

Although TMJ sound is common, its relationship to subjective and objective evaluation and the magnitude and the position of the sound during the mandibular movement is not fully understood. So, the purpose of this investigation was to provide further insight into the characteristics of the TMJ sounds. Twelve subjects (9 men and 3 women) with TMJ sounds were selected from students at Chosun University, School of Dentistry. Condylar movements and TMJ sounds of each subject were recorded and analyzed using a simplified condylar path recorder and a sound checker. Although specific conclusions were difficult to make from this study, the finding suggested the followings. 1. The position of TMJ sounds were visually observed and marked on the condylar tracings during maximum opening and closing, protrusive and retrusive and right and left lateral movements. 2. Information about the size, location and number of condylar deviations and the translation freedom of the condyle was recorded and analyzed objectively. 3. The most obvious characteristic of TMJ sounds was their variability. 4. TMJ sounds were categorized into one of four groups (soft click, hard click, soft crepitus, hard crepitus) by the quality and quantity of the duration and amplitude components.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권4호
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• pp.383-390
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• 2000

The purpose of this study was to compare the soft tissue movements in facial profile predicted by a computer package with those that had actually accured following a sagittal split ramal osteotomy. The reliability of predicting the results of orthodontic surgical treatment was analysed. The study was based on the serial records of 30 consecutive patients who had been treated by means of a sagittal split ramal osteotomy. The serial lateral cephalometric radiographs used for the study were taken at the following stages: immediate preoperative : immediate postoperative : 6 months postoperative. A superimposition T1, T2-3 was generated to allow visual comparision. The results can be considered in relation to four important parts of the facial profile :the nose, upper lip, lower lip, and chin. The nose & Upper lip:The amount of movement of the upper lipwas not badly predicted for the average case. The lower lip: There was a significant trend over the whole sample for vertical positionof the lower lip to be less well predicted. The chin: The soft tissue movements of the chin were well predicted.

• 대한치과교정학회지
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• 제31권6호
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• pp.559-566
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• 2001

본 연구는 설측 이소맹출된 하악 제2대구치의 협측 반대교합을 개선하기 위해 사용되는 mandibular posterior crossbite appliance에 의해 하악 제2대구치의 치근단과 그 주위의 치조골에 발생되는 응력분포를 알아보기 위해 광탄성법을 이용하여 분석하였다. 하악의 치조골을 재현하기 위해 PL-3 형의 epoxy resin과 PL-3 보다 경질인 레진치아를 사용하여 설측 이소맹출된 하악 제2대구치를 광탄성모형으로 재현하였다. 광탄성 모현상에 mandibular posterior crossbite appliance를 적용하고 힘을 가하기 전과후의 응력 분포를 알아보기 위해 원형편광기 를 사용하여 모형의 전후방에서 관찰하였다. 이상의 연구를 통해 얻어진 결과는 다음과 같다. 1. 하악 제2대구치의 협측면에 힘을 가한 경우, 설측 치조정과 치근첨 부위에 응력이 집중되어 나타났고 회전중심이 치근 협측면의 중간 1/3부위와 치근첨 부위에 발생하였으며 이로 인해 제 2대구치에 협측으로의 비조절성 경사이동 및 회전력이 발생하였다. 2. 하악 제2대구치의 설측면에 힘을 가한 경우에는 협측면에 힘을 가한 경우 보다 치근첨에 더 많은 응력이 발생하였다. 또한 치근하방의 치조골 부위에 응력이 증가하였으며 치근의 협측면과 치근첨 부위의 회전중심도 없어져 이로 인한 협측으로의 조절성 경사 이동 및 함입력이 관찰되었다. 3. 하악 제2대구치의 협측이나 설측에 힘을 가한 경우, 고정원인 제1대구치의 치근첨 부위는 힘을 가하기 전의 초기 응력상태와 비교할 때 응력의 증가는 보이지 않아 구치부 협측 반대 교합의 개선시 하악의 설측 호선은 효과적인 고정원으로 사용될 수 있다. 이상의 연구 결과는 설측 이소맹출된 하악 제2대구치의 구치부 협측 반대교합을 개선하기 위해 사용되는 mandibular posterior crossbite appliance를 적용할 때, 제2대구치의 협측면보다는 설측면에서 힘을 부여하는 것이 교합장애를 야기시킬 수 있는 비조절성 경사이동과 구치의 회전을 피하면서 협측으로의 조절성 경사이동 및 함입력을 적용시킬 수 있음을 의미한다.

• 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.

• 대한치과의사협회지
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• 제22권7호통권182호
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• pp.607-620
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• 1984

Mandibular Kinesiograph (MKG-5R)으로부터 얻어지는 자료의 유효성에 관한 연구를 위하여 비철, 비자석성의 기구를 이용해서 3cm×4cm×5cm의 4차원적 입체공간내에서 수행하였다. Kinesiograph로 부터의 직접 얻어지는 자료(관찰치)와 실제 움직인 거리(실제치)간의 관계를 먼저 보기위해 Scatter plot과 Correlation이 연구됐다. 그러나 최종의 목표는 어떤 형태의 공식을 만들어 이것으로 Kinesiograph관찰치를 이용, 실제치를 알도록 하는 것이었으므로 관찰치의 통계학적 회귀분석이 수행되었다. 통계분석의 결과는 Kinesiograph 관찰치와 실제치 간의 강한 상관관계를 보였다. 그러나 높은 상관계수가 반드시 얻어진 선형모형의 완벽한 예측성을 의미하는 것은 아니다. 이 연구로부터 얻어진 선형모형이 실제치를 모두 완벽하게 예측할수는 없었다. 그 이유로서는 종속변수(실제치)의 불연속성과 관찰치(비종속변수) 상호간의 독랩성 때문이다. 결론적으로 Kinesiograph가 어떤 형태로든 적절한 방법에 의해 수정이 있지 않으면 그 계통자체내에 내재하는 비선형적 특성 때문에 그 이용이 하악운동의 제한된 범위내에만 적용될 수 있다.

• 대한치과교정학회지
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• 제52권3호
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• pp.210-219
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• 2022

Objective: The purpose of this study was to examine the effectiveness and mechanism of clear aligner therapy for the correction of anterior open bite in adult nonextraction cases. Methods: Sixty-nine adult patients with anterior open bite were enrolled and classified into Angle's Class I, II, and III groups. Fifty patients presented with skeletal open bite (mandibular plane angle [MPA] ≥ 38°), whereas 19 presented with dental open bite. Fifteen cephalometric landmarks were identified before (T1) and after (T2) treatment. The magnitudes of planned and actual movements of the incisors and molars were calculated. Results: Positive overbite was achieved in 94% patients, with a mean final overbite of 1.1 ± 0.8 mm. The mean change in overbite was 3.3 ± 1.4 mm. With clear aligners alone, 0.36 ± 0.58 mm of maxillary molar intrusion was achieved. Compared with the Class I group, the Class II group showed greater maxillary molar intrusion and MPA reduction. The Class III group showed greater mandibular incisor extrusion with no significant vertical skeletal changes. Conclusions: Clear aligners can be effective in controlling the vertical dimension and correcting mild to moderate anterior open bite in adult nonextraction cases. The treatment mechanism for Class III patients significantly differed from that for Class I and Class II patients. Maxillary incisor extrusion in patients with dental open bite and MPA reduction with mandibular incisor extrusion in patients with skeletal open bite are the most significant contributing factors for open bite closure.

• 구강회복응용과학지
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• 제39권3호
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• pp.168-175
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• 2023

부적합한 보철물을 장기간 사용하면 습관성 폐구위나 불규칙한 하악 운동을 보이는 경우가 빈발하다. 이러한 환자는 고정된 중심 위로 유도하는 것이 어려우므로 치료의치를 이용하여 근육과 TMJ를 안정 시키고 치료위로써 악간 관계 채득을 해야한다. 디지털 방식을 이용한 의치 제작은 전통적인 방식과 비교하여 치아 배열이 까다로운 증례에서 안정화된 치아 배열을 재현하여 수작업에 의한 오차를 최소로 하고, 의치 제작 시간을 감소 시킬 수 있다는 장점이 있다. 따라서 본 증례에서는 치료의치로 안정된 치료위, 수직고경 및 구순 지지도를 디지털 방식으로 이행하여 최종 의치를 제작하였으며, 만족스러운 결과를 얻었기에 이를 보고하는 바이다.

• 대한소아치과학회지
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• 제31권3호
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• pp.453-458
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• 2004

소아에서의 하악 골절은 성인에서보다 드물다. 그러나, 어릴수록 강직과 성장장애의 가능성이 크며 성인만큼 악간고정을 잘 견뎌내지 못한다. 반면에, 골절은 소아에 있어 더 빨리 치유되고 합병증도 적다. 소아에서 하악 골절은 종종 하악의 acrylic splint therapy 단독 또는 eyelet wire 와 악간 고정을 같이 사용하여 성공적으로 치료될 수 있다. 발생할 수 있는 심각한 합병증으로는 유착과 성장장애가 있다. 이러한 합병증의 빈도와 심각성은 좀더 짧은 기간의 악간고정과 긴밀한 술 후 관리에 의해 감소될 수 있다. 특히 소아 환자가 악간고정을 잘 견디지 못하는 경우, 악간고정의 기간이 길어지는 경우, 환자의 자발적인 운동요법이 어려운 경우 악간고정이 불필요하고 개구장애 만을 일으킨 미약한 증상의 경우에는 동기부여에 의한 물리적 하악 운동요법이 사용될 수 있다. 본 종례에서는 하악정중부의 외상으로 인하여 양측성 과두 골절이 일어난 6세 여자 환아를 대상으로 상, 하악에 elastic을 이용하여 하악의 개구, 측방, 전방운동에 대해 훈련을 가능하게 하는 Benoist씨 장치를 이용한 능동적 하악 운동 요법으로 7개월 간의 정기 검진을 통하여 하악 운동량의 증진 과두 유착의 방지, 골개조의 치료효과를 보였다.