• 치과방사선
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• 제6권1호
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• pp.27-31
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• 1976

A study was performed to investigate the size of pharynegeal cavity and sexual differences between Korean adult male and female by introducing linear analysis of the lateral cephalogram. The radiograms were composed of 46 adult males aged 24.64 and 52 adult females aged 22.74 respectively. In order to study and measure the pharyngeal area the following skeletal landmarks were selected: S, N, A, Ptm, B, H, H', M, S' N, FH and CV, and the angle CV-FH was measured to provide a factor for correction of error resulting from improper head positioning of subjects, especially in the relative positions of A and H, while radiography. All points to be measured were projected at right angles to the Frankfort plane. For the purpose of measuring the anteroposterior dimensions of pharyngeal cavity the distances were measured in A-Ptm, A-S, S-Ptm and CV-H, and vertical measurements were made in SN-A, SN-PNS, SN-H' and M-H'. The obtained results were as follows: 1. The pharyngeal cavity is broader in the vertical than in the anteroposterior diameter in both sex and the maxium sexual differences were showed in the distances between SN and H', and minimal sexual differences in the distances between S and Ptm. 2. In general, the measurements of male were larger than those of female in the anteroposterior dimensions of pharyngeal cavity, but the distances bet-ween A and S, between CV and H showed significant sexual differences when evaluated statistically. 3. All of the measurements were larger in male than in female in vertical dimensions of pharyngeal cavity, and there were statistical significances of sexual differences in all variables.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권2호
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• pp.129-137
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• 2006

The treatment plan for orthognathic surgery must be based on accurate predictions, and this can be produced the most esthetic, functional and stable results. The purpose of this study was aimed to evaluate the amount and interrelationship of the gonial angle and the mandibular width change after the mandibular setback surgery in the mandibular prognathic patients. Twenty patients were selected who received orthognathic surgery after presurgical orthodontic treatment. The patients with skeletal and dental Class III malocclusion were operated upon with bilateral sagittal split ramus osteotomy and mandibular setback. The lateral and posteroanterior cephalometric radiographs were taken preoperatively, postoperative 1 day and 12 months later after the orthognathic surgery, and then the gonial angle and mandibular width were measured. The computerized statistical analysis was carried out with SPSS/PC program. The gonial angle at postoperative 1 day was decreased about $5.3^{\circ}$ than preoperative value and the gonial angle at postoperative 12 months was increased about $1.4^{\circ}$ than postoperative 1 day. So the gonial angle at postoperative 12 months was decreased about $3.9^{\circ}$ than preoperative value. The mean preoperative gonial angle was $125.35^{\circ}{\pm}7.36$, showing significantly high value than normal and mean gonial angle at postoperative 12 months was $121.45^{\circ}{\pm}6.81$, showing value near to normal. The mandibular width at postoperative 1 day was decreased about 1.1 mm than preoperative value and the mandibular width at postoperative 12 months was more decreased about 1.7 mm than postoperative 1 day. So the mandibular width at postoperative 12 months was decreased about 2.8 mm than preoperative value. These results indicate that sagittal split ramus osteotomy in mandibular prognathic patients with high gonial angle is effective to improvement of gonial angle. It is considered to be helpful for maintenance of postoperative stable gonial angle area that detailed postoperative care and follow-up.

• 대한소아치과학회지
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• 제45권1호
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• pp.21-31
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• 2018

본 연구는 7세에서 11세 사이의 혼합치열기 아동의 전치 경사도와 입술 경사도 사이의 연관성을 알아보고자 하였다. 353명의 측모두부방사선 사진을 분석하여, 골격성 부정교합의 분류에 따른 상악 전치 경사도, 하악 전치 경사도, 하-비순각, 이순각을 평가하였다. 측정된 수치는 Kruskal-Wallis test와 피어슨 상관분석 및 다중회귀분석을 통해 평가하였다. 모든 골격성 부정교합에서 상악 전치 경사도와 상순 경사도 사이에는 유의한 음의 상관관계가 확인되었고, 하악 전치 경사도와 하순 경사도 사이에는 음의 상관관계가 확인되었으나 2급 부정교합에서는 유의할만한 양의 상관관계가 확인되었다. 본 연구를 통해 입술 경사도에 영향을 미치는 요인들을 확인하고 그 연관성을 확인할 수 있었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권6호
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• pp.426-431
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• 2012

Purpose: The aim of this study was to evaluate the effect of temporary mandibular advancement devices (MAD) in obstructive sleep apnea (OSA) patients Methods: 28 patients (male 21, female 7) undergoing temporary mandibular advancement device treatment for OSA were selected from 2011.01. to 2012.02. in the department of Oral & Maxillofacial Surgery at SamsungMedicalCenter. Treatment efficacy was determined by polysomnography (PSG) at baseline & after MAD delivery. The response group was defined as >50% Apnea-Hypopnea Index (AHI) reduction plus post-MAD AHI <10, and the non-response group was defined as <50% AHI reduction. The lateral cephalogram was analysed including SNA, SNB, UL, MPH, PAS, PASU, and PAST using V-ceph$^{TM}$ (Cybermed, USA). Results: The responsers were 23 patients, and non-responsers were 5 patients. The AHI was significantly reduced with temporary MAD ($8.08{\pm}7.93$) compared with baseline ($28.51{\pm}20.56$) in the response group (n=23). No significant difference was observed between pre MAD and post MAD except SNB on cephalometric analysis. Among 11 patients successfully treated with the temporary device, 9 patients said that using permanent device brings better effect too. Conclusion: These results indicate that the Temporary MAD could not be the only effective tools on OSA but also be used to predict patient's reactivity about permanent appliance treatment. Further studies are warranted to evaluate the relations between temporary MAD and permanent MAD.

• 대한치과교정학회지
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• 제50권3호
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• pp.216-226
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• 2020

Root resorption can be caused by several factors, including contact with the cortical bone. Here we report a case involving a 21-year-old female with Angle Class II, division 1 malocclusion who exhibited significant root resorption in the maxillary right central incisor after orthodontic treatment. The patient presented with significant left-sided deviation of the maxillary incisors due to lingual dislocation of the left lateral incisor and a Class II molar relationship. Cephalometric analysis demonstrated a Class I skeletal relationship (A point-nasion-B point, 2.5°) and proclined maxillary anterior teeth (upper incisor to sella-nasion plane angle, 113.4°). The primary treatment objectives were the achievement of stable occlusion with midline agreement between the maxillary and mandibular dentitions and appropriate maxillary anterior tooth axes and molar relationship. A panoramic radiograph obtained after active treatment showed significant root resorption in the maxillary right central incisor; therefore, we performed cone-beam computed tomography, which confirmed root resorption along the cortical bone around the incisive canal. The findings from this case, where different degrees of root resorption were observed despite comparable degrees of orthodontic movement in the bilateral maxillary central incisors, suggest that the incisive canal could be an inducing factor for root resorption. However, further investigation is necessary to confirm this assumption.

• 치과방사선
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• 제7권1호
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• pp.31-38
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• 1977

A study was performed to investigate the size of tongue area and intermaxillary space area, and compare the sexual differences between normal Korean children and adults by introducing planimetric and linear analysis of the lateral cephalograms. The cephalograms were composed of 41 child male aged 10.8, 40 child female aged 10.5, 38 adult male aged 21.3 and 40 adult female aged 20.8 respectively. In order to study and measure the intermaxillary space area, the followings were selected, as reference items: occlusal plane, anterior intermaxillary space height, posterior intermaxillary space height, length of intermaxillary space. Among those reference items anterior intermaxillary space height and posterior intermaxillary space height were perpendicular to the maxillary plane. An. index, (equation omitted) While the tongue area was plotted by outline of tongue shadow, above a line extending from the vallecula to the most anterior point on the hyoid body, and above a line from the most anterior point of the hyoid body to the menton. The obtained results were as follows: 1. In general the measurements of male were larger than those of female in intermaxillary space area in childhood and adulthood group. but intermaxillary space area of childhood group showed no significant sexual difference, and that of adulthood group showed significant sexual difference when evaluated statistically. 2. In both groups the measurements of male were larger than those of female in tongue area and there are also statistical significance of sexual differences in both age groups. 3. Considerable growh changes between the childhood and adulthood groups were revealed in intermaxillary space area and tongue area, and the tongue had tendency to become relatively smaller when compared with the intermaxillary space in both sex.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권3호
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• pp.274-278
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• 2005

Purpose : Prediction for soft tissue change after orthognathic surgery is very important for the final esthetics. In this study, we have tried to get the amount of upper lip movement relative to bony segment movement after anterior segmental osteotomy by cephalmetric analysis to predict final upper lip position after surgery. Material and Methods : 20 patients was studied on whom anterior segmental osteotmy as performed by Cupar method during the years 2002 to 2003. Cephalometric radiograph were taken at 1month before surgery and 6 month after surgery. Change of upper lip was measured on landmark Ls and Sto relative to hard tissue (landmark Ia) setback on these X-rays and analyzed. Results : 1. Upper lip setback movement. Setback of upper lip showed proportional relation to the hard tissue setback and the ratio was about 84%(p=0.001). 2. Upper lip downward movement. Downward movement of upper lip showed no proportional relation to hard tissue setback And the amount was mean 1.38 mm and SD 1.21mm (p=0.922). Conclusion : The posterior movement of upper lip is affected by hard tissue movement and shows good proportional change whereas downward movement is not so much influenced by hard tissue movement. And we think slight downward movement shown in this study could be explained by the V-Y closure performed during surgery.

• 대한치과의사협회지
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• 제45권8호통권459호
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• pp.483-490
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• 2007

The aim of this study was to investigate the relationship between the mandibular antegonial notch and the mandibular morphology, and the curve of Spee in anteroposterior skeletal relationship. Pre-treatment lateral cephalograms were obtained from 80(male 34, female 46) adult orthodontic patients and the samples were classified into 3 categories by ANB angle($0^{\circ}$$\leq$ANB< $4^{\circ}$ Class I, $4^{\circ}$$\leq$ANB Class II, ANB< $0^{\circ}$ Class III). The curve of Spee was measured directly from the pre-treatment mandibular study cast of each patient included in this study. Pearson correlation coefficient test and multiple regression analysis in each group revealed the following results; 1. Antegonial notch depth was positively correlated with hoth lower anterior facial height(ANS-Me) in skeletal Class I, II and III groups and Id-Me height in skeletal Class I and II groups. 2. A statistically significant negative correlation was found between the depth of the antegonial notch and the curve of Spee in the Class III group. 3. Significant relationship was not found between the antegonial notch depth and any of the other cephalometric variables such as mandibular body length(Go-Gn) and ramus height(Co-Go). As antegonial notch depth increased, more vertical growth of the mandible was observed. Antegonial notch can be used as a predictor of vertical mandibular growth in the diagnosis and treatment planning of malocclusion.

• International Journal of Oral Biology
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• 제46권4호
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• pp.168-175
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• 2021

To investigate the perceptions and attitudes of dental hygienists toward radiation safety management in Korea. A total of 800 dental hygienists were randomly selected for an anonymous survey, and 203 of them participated. The questionnaire items included the following: sex, career period, type of installed radiographic equipment, recognition of the diagnostic reference level (DRL), participation in radiation safety education, and attitudes toward radiation protection for both patients and dental hygienists. The participants were divided into two groups according to their years of experience (< 10 years versus ≥ 10 years). The difference between the groups was investigated according to frequency distribution. Fisher's exact test or Pearson's chi-square (𝛘²) test was used as appropriate. A regression analysis was performed to investigate the impact of wearing a thyroid collar for personnel protection during patient radiation exposure. The types of installed radiographic equipment included panoramic radiography (96.1%), cephalometric radiography (76.9%), intraoral radiography (72.9%), and cone-beam computed tomography (69.5%). Significant differences were observed in the learning pathway for the DRL (Fisher's exact test, p < 0.05), satisfaction with radiation safety education (Pearson's 𝛘² test = 5.3975, Pr = 0.02), and use of personnel radiation monitoring systems (Pearson's 𝛘² test = 18.1233, Pr = 0.000) between the groups. Significant differences were also observed in personnel protection using a thyroid collar and patient protection during panoramic radiography (odds ratio = 14.2). Dental hygienists with more than 10 years of experience were more satisfied with radiation safety education and more interested in radiation monitoring. Considering career experience, customized, continuous, and effective radiation safety management education should be provided.

• 대한치과교정학회지
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• 제53권4호
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• pp.276-285
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• 2023

Objective: The aim of this retrospective study was to compare changes in hard tissue and soft tissue after the four first premolars were extracted with anterior teeth retraction according to the presence or absence of lip incompetence. Methods: Patients who underwent the four first premolars were extracted with anterior teeth retraction were divided into competent (n = 20) and incompetent lip (n = 20) groups. Cephalometric measurements for hard tissue and soft tissue changes were performed pre-treatment and post-treatment. Results: In the competent group, the upper and lower lips retreated by 2.88 mm and 4.28 mm, respectively, and in the incompetent group by 4.13 mm and 5.57 mm, respectively; the differences between the two groups were significant (p < 0.05). A strong positive correlation between retraction of the upper lip and upper incisors was observed in both groups (p < 0.05), whereas a correlation between retraction of the lower lip and lower incisors was only found in the incompetent group. A simple linear regression analysis showed that the pattern of lip retraction following the retraction of the anterior teeth was more predictable in the incompetent group than in the competent group. Conclusions: These findings suggest that the initial evaluation of lip incompetence in patients with skeletal Class II is essential for the accurate prediction of the soft tissue changes following retraction of the anterior teeth in premolar extraction treatment. Therefore, sufficient explanation should be provided during patient consultations.