• 대한치과교정학회지
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• 제52권1호
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• pp.53-65
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• 2022

Objective: Planning of incisal position is crucial for optimal orthodontic treatment outcomes due to its consequences on facial esthetics and occlusion. A systematic summary of the proposed parameters is presented. Methods: Studies on Google Scholar^©, PubMed^©, and Cochrane Library, providing quantitative information on optimal central incisor position were included. Results: Upper incisors supero-inferior position (4-5 mm to upper lip, 67-73 mm to axial plane through pupils), antero-posterior position (3-4 mm to Nasion-A, 3-6 mm to A-Pogonion, 9-12 mm to true vertical line, 5 mm to A-projection, 9-10 mm to coronal plane through pupils), bucco-lingual angulation (4-7° to occlusal plane perpendicular on models, 20-22° to Nasion-A, 57-58° to upper occlusal plane, 16-20° to coronal plane through pupils, 108-110° to anterior-posterior nasal spine), mesio-distal angulation (5° to occlusal plane perpendicular on models). Lower incisors supero-inferior position (41-48 mm to soft-tissue mandibular plane), antero-posterior position (3-4 mm to Nasion-B, 1-3 mm to A-Pogonion, 12-15 mm to true vertical line, 6-8 mm to coronal plane through pupils), bucco-lingual angulation (1-4° to occlusal plane perpendicular on models, 87-94° to mandibular plane, 68° to Frankfurt plane, 22-25° to Nasion-B, 105° to occlusal plane, 64° to lower occlusal plane, 21° to A-Pogonion), mesio-distal angulation (2° to occlusal plane perpendicular on models). Conclusions: Although these findings can provide clinical guideline, they derive from heterogeneous studies in terms of subject characteristics and reference methods. Therefore, the optimal incisal position remains debatable.

• 대한치과보철학회지
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• 제32권3호
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• pp.396-410
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• 1994

Ten subjects who were going to wear conventional complete dentures were selected for this study. Theree subjects were women and seven were men. The average age was 63.1 years(range : 44 to 76 years). With the Height tracer (extraoral tracing device) in place the subject was instructed to go through the entire range of mandibular movements. The extreme lateral pathway of the incisor point, the so-called Gothic arch, was thereby inscribed by the stylus on the tracing plate. The mandibular movements in this study were peformed voluntarily by the subject(self guided technique) and guided by the dentist(chin-point technique and bimanual technique). The Gothic arch tracings were analysed and the Gothic arch angles and eccentric movement distances were measured. The results were as follows : 1. The apex position of the Gothic arch tracings of mandibular movements in edentulous patients varied both anterioposteriorly and mediolaterally. 2. The Gothic arch tracing had some lateral deviation during protrusion. 3. The average Gothic arch tracing angle was $136.7{\pm}12.0^{\circ}$ by subjects self guided technique, $135.7{\pm}5.9^{\circ}$ by chin-point technique, $136.6{\pm}6.5^{\circ}$ by bimanual technique. But there were no statistical differences in the reliability among the three techniques. 4. The average mandibular eccentric movements were irregular and the mandibular eccentric movement distances varied with a wide range.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권3호
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• pp.218-224
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• 2011

Purpose: The purpose of this study is to evaluate the post-operative skeletal stability after surgical correction of patients with mandibular prognathism by bilateral sagittal split ramus osteotomy (BSSRO) and to evaluate the horizontal relapse tendency after the surgery. Methods: Twenty-six patients with Class III dental and skeletal malocclusion were selected for this retrospective study. Fifteen of them underwent BSSRO for mandibular setback and eleven of them underwent two-jaw surgery (Lefort I and BSSRO). In each patient, lateral cephalometric radiographs were taken pre-operatively, post-operatively within 1 week, and post-operatively after eight months. After tracing of the cephalometric radiographs, various parameters were measured. The analyses were done by linear measurement to evaluate the change in position of hard tissue B point, pogonion and mandibular plan angle by examination on lateral cephalograms. Results: The horizontal relapse rate was 27.1% at B point and 31.6% at pogonion in patients who underwent BSSRO. The horizontal relapse rate of the group where the amount of correction exceeded 10 mm was 25.69% at B point. Conclusion: There were no statistical differences on the magnitude of setback and direction of rotation of the mandible in mandibular stability. There were also no statistical differences between single mandibular surgery and two-jaw surgery for mandibular stability.

• 대한치과보철학회지
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• 제33권4호
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• pp.718-730
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• 1995

This study was performed to measure the mandibular movement and the changes of masicatory and sternocleidomastoid muscle activity reflected by occlusal disturbance during habitual chewing. For this study, 18 subjects(14 males and 4 females with an average age of 24.0) were selected. The impression of each subject were taken for measuring intermolar distance on lower dentition. The activities of masticatory and sternocleidomastoid muscle and the mandibular movement were recorded and analyzed during habitual chewing by means of E.M.G.(electromyograph), E.G.N.(electrognathograph), rotate program in BioPak analyzing system(BioResearch Inc.). The results were as follows : 1. In EMG of the mandibular rest position, the mean value of muscle activites were increased by nocleidomastoid muscle and anterior belly of digastric muscle(0.05

• Journal of Oral Medicine and Pain
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• 제25권2호
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• pp.191-203
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• 2000

This study was performed to investigate the relationship between vertical dimension during swallowing and speech pattern in patients with temporomandibular disorders. For this study, 33 patients with temporomandibular disorders(TMDs), namely, 17 patients with disc displacement with reduction and 16 patients with disc displacement without reduction, and 30 normal subjects without any signs and symptoms in the masticatory system were selected as the patient group and as the normal group, respectively. Biopak $system^{(R)}$(Bioresearch Inc., Milwaukee, USA) was used for recording of electromyographic(EMG) activity(${\mu}V$) of the anterior temporalis, the superficial masseter, the sternocleidomastoideus and the trapezius insertion muscle during swallowing, and of mandibular positional change with function time(sec.) during swallowing and speech. A sentence of 'Sue is missing her house' was used for observing of speech pattern. Comparison between the two groups and relationship of the mandibular positional change and the function time between during swallowing and during speech were analysed by SPSS windows program. The results of this study were as follows : 1. Mean EMG activity of the trapezius insertion during swallowing was higher in the patient group, and the value was $3.4{\mu}V$ in patients and $2.1{\mu}V$ in normal subjects. 2. Vertica1 dimension(VD) at mandibular rest position before swallowing was slightly higher in the patient group, but VD at swallowing-late stage and at rest position after swallowing were not different between the two groups. 3. Swallowing time were 2.1 sec. in the patient group, and 1.5 sec. in the normal group, and the difference was significant. 4. VD during speech were generally higher in the normal group. In this case, speaking position showing the most difference between the two groups was 'her' position. The distance from habitual intercuspal position to 'her' position was 4.9mm in the patient group, and 6.6mm in the normal group. Speaking time was also longer in the patient group. 5. There were no difference in all observed items between the two categories of the patient group according to reduction of disc displacement. 6. Relationship between the positional changes during swallowing and speech were different between the patient group and the normal group. And in the normal group, VD at rest position before swallowing was negatively correlated with speaking time.

• 치위생과학회지
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• 제7권4호
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• pp.275-279
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• 2007

본 연구는 하악 제3대구치의 맹출 양상이 치관주위염의 발생에 미치는 영향을 조사하고자 양산시에 소재한 N치과병원에 하악 제3대구치 발거를 주소로 내원한 환자 200명을 대상으로 조사연구를 실시하였다. 하악 제3대구치의 좌 우측 분포도, 경사도, 매복정도, 하악지 전연에서의 위치, 하악 제2대구치와 제3대구치 사이의 거리는 $X^2$-test, 치관주위염 유 무와 제 변수와의 상관성은 Pearson 상관관계를 실시하여 다음과 같은 결론을 얻었다. 1. 하악 제3대구치에 대한 치관주위염의 발생은 연령과 상관관계가 있는 것으로 나타났다. 2. 하악 제3대구치의 경사도에 있어서 치관주위염이 가장 호발된 군은 근심경사군이었다. 3. 하악 제3대구치의 매복정도와 치관주위염의 발생은 Level a, Level c, Level b순으로 나타났다. 4. 하악 제3대구치의 하악지 전연에서의 위치는 Class II, I, III의 순으로 치관주위염이 호발하였다. 5. 하악 제2대구치의 원심 백악법랑경계에서 하악 제3대구치의 근심 백악법랑경계까지의 거리가 좁을수록 치관주위염이 호발하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권1호
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• pp.27-34
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• 2006

After orthognathic surgery in skeletal class III patients, the hyoid bone position and the upper airway dimension could be changed due to mandibular setback. There has been many studies about airway dimension of the patients with skeletal class II malocclusion or obstructive sleep apnea. but not with skeletal class III. The purpose of this study was to examine the change of position of the hyoid bone and the consequent change of airway space as the result of retrusion of mandible after orthognathic surgery in skeletal Cl III malocclusion patients. It is also to apply this results in predicting, diagnosing and treating the subsequent obstructive sleep apnea. Forty patients who were diagnosed as skeletal Cl III maloccusion, received orthoganthic surgery of both jaws including mandibular setback, and were followed up post-operatively for more than 6 months were selected. There were 10 male patients 30 female patients. The preoperative and postoperative lateral cephalograms were traced and the distances and angles were measured. The nasopharyngeal space increased postoperatively while the oropharyngeal space decreased. Except for the change of oroparyngeal space, the changes in male patients were greater than female patients. The hyoid bone moved in the posterior-inferior direction, and the change was greater in males than in females. If the postoperative mandibular setback is great, then a significant decrease of airway space and posterior and inferior movement of the hyoid bone were observed. This can result in symptoms related to obstructive sleep apnea. This result should be considered in the diagnosis and treatment planning of orthognathic surgery patients.

• Journal of International Society for Simulation Surgery
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• 제2권2호
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• pp.90-93
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• 2015

The fibula free flap has now become the most reliable and frequently used option for mandible reconstruction. Recently, three dimensional images and printing technologies are applied to mandibular reconstruction. We introduce our recent experience of mandibular reconstruction using three dimensionally planned fibula free flap in a patient with gunshot injury. The defect was virtually reconstructed with three-dimensional image. Because bone fragments are dislocated from original position, relocation was necessary. Fragments are virtually relocated to original position using mirror image of unaffected right side of the mandible. A medical rapid prototyping (MRP) model and cutting guide was made with 3D printer. Titanium reconstruction plate was adapted to the MRP model manually. 7 cm-sized fibula bone flap was designed on left lower leg. After dissection, proximal and distal margin of fibula flap was osteotomized by using three dimensional cutting guide. Segmentation was also done as planned. The fibula bone flap was attached to the inner side of the prebent reconstruction plate and fixed with screws. Postoperative evaluation was done by comparison between preoperative planning and surgical outcome. Although dislocated condyle is still not in ideal position, we can see that reconstruction was done as planned.

• 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.

• 구강회복응용과학지
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• 제16권1호
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• pp.37-49
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• 2000

It was clinically important to substitute the physiologic centric relation to the therapeutic position of the patients who needed the oral rehabilitation or occlusal treatment. There were several methods for recording the centric relation. One of the known methods was to use the gothic arch tracer. However the existing intraoral device was difficult to adjust the three dimensional angulation of the recording plate and recording stylus depending on the hinge movement arch of the individual. The purpose of this study was to develop new intraoral tracer which had adjustable stylus within hinge movement arch for the record of centric relation and to evaluate the clinical application of this device. The results were as follow; 1. A stylus of new developed intraoral tracer was so adjustable that the recording of mandibular positions could be reproducible within the hinge movement arc. 2. A record plate of new developed intraoral tracer was so adjustable to parallel with the occlusal plane that lateral recording of mandibular position was able to obtain stably. This study showed that new developed intraoral tracer allowed the determination of the treatment position which can be used in the full mouth rehabilitation and occlusal treatments.