• 대한치과교정학회지
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• 제25권6호
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• pp.665-674
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• 1995

The purpose of this study is to investigate the cephalometric characteristics of the open-bite patients with DJD of TMJ. The DJD open-bite cases were compared with normal samples and Class II open-bite cases with normal TMJ respectively. Twenty three open-bite patients with bilateral DJD of TMJ($13.9\~35.3$ yens old, Group I) were selected from the Department of Orthodontics, SNUDH. Group ll consisted of thirteen Class II open-bite cases($13.2\~27.4$ years old) with no TMD signs/symtoms and good condylar shapes. Group III samples were the forty eight healthy dental students who have Class I molar relationships with no history of orthodontic treatment, good facial balance and no TMD symptoms($20.0\~26.8$ years old). First, sixty measurements in the lateral cephalometric radiographs and analysis of variance(P<0.05, Scheffe) were used to compare these three groups. The seven measurements showed significant difference(p<0.05) between Group I and Group II. After analysis of variance, six of them were used for the discriminant analysis(Wilks' stepwise analysis) and the discrminant function for Group I/Group II was obtained. The results and conclusions were as follows : In most of the measurments, Group I and Group II showed the same skeletal and dental characteristics. But seven of the sixty measurements(FH-PP angle, SNB, FH-ArGo angle, articulare angle, genial angle, upper gonial angle and Ar-Go length) were significantly different(p<0.05) between Group I and Group II. These differences may be explained by the fact that in DJD cases the mandible rotated backward due to the shortening of the ramus following the degenerative destruction of condylar head and its surrounding structures. The resulting discriminant function was : $D={-0.120X}_1+{0.066X}_2+{0.144X}_3-{0.058X}_4+2000,\;where\;X_1=ArGo\;length(mm),\;X_2=SArGo\;angle(degree),\;X_3=FH-PP\;angle(degree),\;X_4=Gonial\;angle(degree)$. Mean of the group centroids was -0.555 and percent of the 'grouped' cases correctly classified was $88.89\%$.

• Journal of Oral Medicine and Pain
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• 제15권1호
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• pp.37-44
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• 1991

The author has synchronously recorded average electromyographic activities of temporalis anteriors and masseter muscles and the maximum bite force on the mandibular first molar on the prferred chewing side. These activities were recorded in order to study the EMG activity pattern of the working side and the balancing side to maximum bete force and functioning state of muscle in 30 patients with TMD and in 30 healthy subjects as controls. The results were as follows : 1. The maximum bite force on the mandibular first molar on the preferred chewing side was 20.63kg in TMD patients and 53.30kg in the healthy subjects(p<0.01). The maximum bite force in TMD patients was 38.7% of the healthy subjects. 2. The average electromyographic activities of temporalis anterioris and masseter muscles on the working side and the balancing side during maximum bite force were lower in TMD patients than in the healthy subjects(p<0.01). The average electromyographic activities of each muscle in TMD patients were 61.0%-62.8% of the healthy subjects. 3. The proportionalities of average electromyographic activities of temporalis anteriors and masseter muscles on the working side and the balancing side to maximum bite force were greater in TMD patients than in the healthy subjects(p<0.01). 4. Between the working side and the balancing side, the proportionality of average electromyographic activity of temporalis anterior to maximum bite force on the working healthy subjects (p<0.01). The proportionality of average electromyographic activity of working side and the balancing side in both groups (p<0.05).

• 대한치과교정학회지
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• 제11권2호
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• pp.109-123
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• 1981

The author studied and analyzed statistically 112 adults female ranging in age from 18 to 20 years with normal occlusion, 56 adults female ranging in age from 18 to 24 years with deep overbite and 53 adults female ranging in age from 18 to 28 years with open bite by vertical cephalometric analysis. The results were as follows; 1. In comparing normal occlusion with deep overbite and open bite, skeletal linear measurements were more significant than dentoalveolar linear measurements. SN-MP angle, SN-OP angle, PP-OP angle and Xi angle (ANS-Xi-Pog) were significant in anglular measurements. 2. Upper posterior facial height (SE-PNS), upper anterior alveolar height, lower posterior alveolar height, lower posterior alveolar height/lower anterior alveolar height and SN-PP angle were non significant between deep overbite and open bite. 3 The most significant items between deep overbite and open bite were lower anterior facial height (ANS-ME) and SN-MP angle. 4. Correlation coefficients of angular measurements were higher in deep overbite, while that of linear measurement total anterior facial height (N-ME) was higher in open bite. 5. In the multiple regression equation, significant variables were total anterior facial height (N-ME), lower anterior alveolar height, upper anterior alveolar height, upper posterior alveolar height, Xi angle (ANS-Xi-Pog) and ramus height (AR-Go) in deep overbite, and total anterior facial height (N-Me), lower anterior alveolar height, ramus height (AR-Go), lower posterior alveolar height, PP-MP angle and upper posterior facial height (SE-PNS) in open bite.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제14권4호
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• pp.327-339
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• 1992

This study was undertaken to investigate the effect of orthognathic surgery on occlusal force. The maximum bite force was measured in 26 dentofacial deformity patients, aged 14-26(mean age 20.3) years, before surgery and at IMF removal, 3, 6, and 12months postsurgery. To grope the correlation of bite force and skeletal change after orthognathic surgery, the cephalometric headplates were measured, tabulated and statistically analyzed. The results were as follows. 1. The presurgical maximum bite force was 13.7kg in upper first molar(rt. Side 12.7kg, it. Side 14.6kg). There was remarkable difference with that of normal occlusion. 2. The recovery of bite force was very significant in according to the operation method and the duration of IMF that was 7.6kg at IMF removal, 14.2kg at 3 months, 19.7kg at 6 months. 26.1kg at 12 months postsurgery. 3. To fasten the recovery and to increase the bite force after orthognathic surgery, the long IMF time and the injury to the masticatory muscle should be avoided by the internal rigid fixation and early physical exercise. 4. The bite force was positively correlated to the changes of mandibular plane angle, the angle between platatal plane and mandibular plan, the angle between occlusal plane and mandibular plane, and negatively correlated to the changes of mandibular body length in craniofacial structure. 5. There was no correlationship between bit force and mesial inclination of tooth long axis of first molar in this subject. 6. There was no correlation between the changes of bite force and the changes of mechanical advantage of the temporal and masseter muscle.

• Archives of Plastic Surgery
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• 제35권2호
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• pp.165-168
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• 2008

Purpose: The dog bite injury is expected to increase as westernizing lifestyle and the number of pet raisers increase. The bite injuries may cause serious sequelae. The purpose of this study is to contributes to establish a suitable management and treatment principle for domestic situation with a clinical analysis data of the dog bite injuries. Methods: We reviewed the hospital records of 76 patients with dog bite injuries who were treated in the emergency unit or out patient department of our hospital from January 2000 to May 2006. Results: The majority of patients were children less than 10 years of age, 21 case(27.6%). Injuries occurred most often in May and 14 patients(18.4%) were bitten by the kinds of Cockerspaniel. By Lackmann's classification, 36 patients(47.4%) had Stage I injuries, 27 patients (35.5%) Stage II, 11 patients(14.5%) Stage III and 2 patients(2.6%) Stage IVa. The most frequent injury site was the head and neck area with 55 cases(72.4%). Also, 58 cases(76.3%) were received the initial treatment within 30 minutes after being bitten and the most of case except emergency operation repaired within 3 days.Conclusion: The dog bite injuries increased by more than 20% every year over the study period and it says that it may continue to increase more in the future. However, There are little report or literature for suitable management and treatment principle for domestic situation. The authors think this clinical analysis data and treatment experience can be useful for establishing a suitable treatment principle for domestic situation.

• Imaging Science in Dentistry
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• 제47권3호
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• pp.157-164
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• 2017

Purpose: This study determined and compared the distances from the maxillary root apices of posterior teeth to the floor of the maxillary sinus, or maxillary sinus distances(MSDs), and the distances from the mandibular root apices of the posterior teeth to the mandibular canal, or mandibular canal distances(MCDs), in Thai subjects with skeletal open bite and skeletal normal bite. Materials and Methods: Pretreatment cone-beam computed tomography (CBCT) images were obtained from 30 Thai orthodontic patients (15 patients with skeletal normal bite and 15 with skeletal open bite) whose ages ranged from 14 to 28 years. The CBCT images of the patients were processed and measured using the Romexis Viewer program. The MSDs and MCDs from the root apices of the maxillary and mandibular second premolar, first molar, and second molar to the maxillary sinus floor or the mandibular canal were measured perpendicularly to the occlusal plane. The Student t test was used for comparisons between the 2 groups. Results: The greatest mean MSDs were from the root apex of the second premolars in both groups, whereas the least mean MSDs were from the mesiobuccal root apex of the second molars. The greatest mean MCDs were from the mesial root apex of the first molars, whereas the least mean MCDs were from the distal root apex of the second molars. Conclusion: There were no differences in the mean MSDs or the mean MCDs between the skeletal normal bite group and the skeletal open bite group.

• Imaging Science in Dentistry
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• 제48권1호
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• pp.51-57
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• 2018

Purpose: To perform a comparative analysis of the palatal bone thickness in Thai patients exhibiting class I malocclusion according to whether they exhibited a normal or open vertical skeletal configuration using cone-beam computed tomography (CBCT). Materials and Methods: Thirty CBCT images of Thai orthodontic patients (15-30 years of age) exhibiting class I malocclusion with a normal or open vertical skeletal configuration were selected. Palatal bone thickness was measured in a 3.0-mm grid pattern on both the right and left sides. The palatal bone thickness of the normal-bite and open-bite groups was compared using the independent t-test. The level of significance was established at P<.05. Results: The palatal bone thickness in the normal-bite group ranged from $2.2{\pm}1.0mm$ to $12.6{\pm}4.1mm$. The palatal bone thickness in the open-bite group ranged from $1.9{\pm}1.1mm$ to $13.2{\pm}2.3mm$. The palatal bone thickness was lower at almost all sites in patients with open bite than in those with normal bite. Significant differences were found at almost all anteroposterior sites along the 3 most medial sections (3.0, 6.0, and 9.0 mm lateral to the midsagittal plane)(P<.05). Conclusion: Class I malocclusion with open vertical skeletal configuration may affect palatal bone thickness, so the placement of temporary anchorage devices or miniscrew implants in the palatal area in such patients should be performed with caution.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권1호
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• pp.25-33
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• 2004

The purpose of this study was to evaluate the postoperative stability of the severe open bite or mandibular prognathic patients after mandibular set back surgery by Obwegeser II method. There were 19 patients who had been undergone Obwegeser II method. The horizontal and vertical position of the cephalometric points were measured preoperation and immediate postoperation, postoperative 1 month, postoperative 6 months ; were analyzed by linear measurement to evaluate changes in skeletal landmark and the relapse was compared between open bite group and prognathism group. By the operation, horizontal change of B was $6.84{\pm}4.35mm$ and vertical change of B was $6.28{\pm}3.25mm$ in open bite group and horizontal change of B was $14.20{\pm}4.81mm$ and vertical change of B was $1.99{\pm}2.66mm$ in prognathism group, horizontal change of Pog was $3.82{\pm}5.71mm$ and vertical change of Pog was $5.38{\pm}2.11mm$ in open bite group and horizontal change of Pog was $13.24{\pm}5.99mm$ and vertical change of Pog was $1.91{\pm}0.94mm$ in prognathism group. Between immediate postoperation and postoperative 1 month, all skeletal landmarks change was no statistical difference (p>0.05) and there were no statistical difference between open bite group and prognathism group except x-Me landmark (p>0.05). Between postoperative 1 month and 6 months, horizontal change of B was $0.12{\pm}1.35mm$ and vertical change of B was $1.47{\pm}1.48mm$ in open bite group and horizontal change of B was $1.43{\pm}1.35mm$ and vertical change of B was $0.82{\pm}1.99mm$ in prognathism group, horizontal change of Pog was $0.13{\pm}1.40mm$ and vertical change of Pog was $0.88{\pm}1.71mm$ in open bite group and horizontal change of Pog was $1.08{\pm}1.74mm$ and vertical change of Pog was $0.47{\pm}1.57mm$ in prognathism group (p>0.05) and there were no statistical difference between open bite group and prognathism group (p>0.05). Between immediate postoperation and postoperative 6months, horizontal change of B was $0.24{\pm}1.17mm$ and vertical change of B was $1.87{\pm}1.63mm$ in open bite group and horizontal change of B was $1.54{\pm}1.55mm$ and vertical change of B was $1.04{\pm}1.96mm$ in prognathism group, horizontal change of Pog was $0.91{\pm}1.46mm$ and vertical change of Pog was $1.18{\pm}2.05mm$ in open bite group and horizontal change of Pog was $0.96{\pm}1.62mm$ and vertical change of Pog was $1.23{\pm}2.35mm$ in prognathism group (p>0.05) and there were statistical difference between open bite group and prognathism group in x-B, x-Pog, x-Gn, x-Me (p<0.05). Obwegeser II method is considered as one of the best operation when surgical correction of severe open bite or severe mandibular prognathism is needed.

• 한국치위생학회지
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• 제8권2호
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• pp.53-66
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• 2008

There was to purpose of this study improves analyzing cause that prosthesis brings bite engaging that is inaccurate in patient's mouth, when supposed that all conducts that do in operatory and dental laboratory are perfect. Impression did check bite by alginate impression material and polymerization style silicon impression material that use usually in presence at a sickbed Irreversibility, hydrocolloid, alginate impression material washed in flowing water and poured anhydrite after wait about 8 minutes so that region that charge interest after impression check bite may become undoing. And hydrophile property addition polymerization style impression material poured anhydrite after blow 30 considering impression material dwell time and H2 gas occurrence time (5~15 minute) after have washed in flowing water. I got each 7 models, result that manufactures total 28 and measures by third dimension measuring instrument (Meteo, Korea) following sequence curing in tray holder and floor 1, By Alginate impression when is hardened in tray holder and when is hardened in the floor after do check bite, SPH 4, SPH5 all as there is synonymy appeared(P<0.05). By in case do not use average 0.1741 in case use tray holder in 0.0447 SPH5s in case do not use average 0.2838 pastas in case use tray holder in SPH4 0.0309, When did not use both SPH4 and SPH5 tray holder, when used tray holder, 1 appeared more greatly. 2. By amity sex addition polymerization style silicon impression when is hardened in tray holder after do check bite and when is hardened in the floor SPH 4, a11 of the SPH5s very big synonymy be(P>0.05). And in case use tray holder in 0.000657 pasta SPH5s in case do not use average 0.000129 pastas in case use tray holder in SPH4 average 0.000114 pastas, by in case do not use 0.000757, I appeared more greatly when used tray when did not use both SPH4 and SPH5 tray holder, but 1 appeared is not level to keep in mind(Table 8~9). 3 SPH4 was looked very big mindfulness in model that manufacture doing impression check bite by Alginate and model that do impression check bite by amity sex accessory penalty silicon without using tray holder(P< 0.001). I use tray holder and SPH4 did not appear synonymy in model that manufacture doing impression check bite by Alginate and model that do impression check bite by amity sex accessory penalty silicon(P>0.05). Study finding of above when see synthesis Alginate certainly tray holder use must and I could know that hardening method does not exert big influence on volume stability if remove impression sieve of excess because amity sex accessory penalty silicon passes over tray, Also, Alginate impression material previewed can get heading a conspiracy style that volume stability of accessory penalty silicon impression material degree is if use tray holder.

• 한국소음진동공학회논문집
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• 제15권1호
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• pp.20-28
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• 2005

이 논문에서는 기존의 6-축 혹은 9-축 머리진동 측정장치(bite-bar)를 이용한 머리진동 측정에서 직면하는 불확도 인자들에 대한 문제점을 우선 소개한다. 이들 불확도 인자들은 머리의 6-자유도 운동 성분의 추정에 필요한 모든 측정 요소들을 측정하지 않았다는 한계점에서 유발함을 보인다. 이러한 문제점을 극복하기 위하여 4개의 3축 가속도 센서로 구성된 새로운 머리진동 측정장치(12-axis bite-bar)의 모델을 제안한다. 본 모델은 측정 기준점에서의 선형 3축 가속도 뿐 아니라 3축 각 가속도와 함께 6 종의 2차 각속도 성분들의 추정 또한 가능하게 한다. 이러한 12 성분의 추정 모델로부터 비로소 머리의 임의 점에서 6-자유도 운동 성분의 계산이 가능함을 이론적으로 규명한다. 이러한 이론적 배경에 기반을 두고 설계 제작된 12-축 머리진동 장치(12-axis bite-bar)를 소개한다. 본 장치를 이용하여 얻어진 실험 결과 소개 뿐 아니라 기존의 측정장치의 측정 결과와 비교 분석 내용을 소개한다.