• Archives of Plastic Surgery
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• v.33 no.2
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• pp.255-258
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• 2006

Nasions are flat and located more caudally in Asian than in Caucasian. Implant insertions in rhinoplasties are apt to move nasions more cephallic, which can cause unsatisfactory results in Asian. The purpose of this study is introducing a simple technique in rhinoplasty avoiding unnatural nasion in augmentation rhinoplasty in Asian patients. Multiple radiating incisions were made at nasion level on inner side of silicone implant to fit it into the curvature around the nasion. Between October 2001 and October 2003, 27 patients underwent augmentation rhinoplasties using this technique and results were evaluated. Preoperative and postoperative photographs of patients were used to measure the levels of nasion from medial canthus. The mean nasion level from medial canthus of preopertive patients were $3.46{\pm}0.87mm$ and postoprative patient was $4.98{\pm}0.96mm$. The mean difference between preoperative nasion level and postoperative nasion level was 1.52 mm. There was no complication such as extrusion, displacement or infection. This technique of radiating incisions on inner side of the silicon implant can minimize cephalic migration of the nasion level in augmentation rhinoplasty in Asian.

• The korean journal of orthodontics
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• v.27 no.4 s.63
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• pp.633-641
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• 1997

Spatial change of craniofacial structures from growth or orthopedic force is usually evaluated by cephalometric superimpositions at different points in time.As the evaluation cu be changed according to cephalometric superimposition method,selettion for correct superimposition method is very important.Double registration of nineteen pairs of female lateral head films,their growth period is average 3.7 years and age is overage 10.7 years,were performed by two observers.Comparisions was made between two methods and the results revealed the following, 1. NS line and ACB superimpositions ate not markedly different in reliability due to almost same registration error of them. 2. The investigation was undertaken to examine interobserver difference.In NS line method, there is no significance in all measurements. In ACB method,significant difference was revealed in 4 measurements of 7 measurements was 3. In the investigation of intermethod difference, there is no significance between NS line and ACB superimpositions

• Journal of Korean Neurosurgical Society
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• v.41 no.3
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• pp.171-176
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• 2007

Objective : The purpose of this study was to characterize the Rolandic fissure[Rf] and was to identify the Rf using the surface bony landmarks which can be usually exposed on craniotomy. Methods : After morphological evaluation of the Rfs using 21 Korean adult formalin fixed cadavers, craniometric measurement was carried out from the surface bony landmarks of nasion, glabella, bregma, and lambda. Results : The Rfs of both hemispheres did not show the mirror image. The Rfs ran forward and downward toward the sylvian fissure keeping the mean angle of $67^{\circ}$ from mid-sagittal line as elongated S-shape in left and the elongated reverse S-shape in right hemisphere. Connections between the Rf and the longitudinal fissure and between the Rf and the sylvian fissure were found in 3 [7.1%] and 2 [4.8%] of 42 hemispheres, respectively. Most Rfs extended superiorly to 2-3mm lateral to the most superomedial surface of hemispheres and extended inferiorly to 3-5mm superior to the sylvian fissures. The mean distances from the nasion, glabella, bregma, and lambda to the most superomedial aspect of the Rf were $18.8{\pm}0.9cm,\;16.6{\pm}0.8cm,\;5.2{\pm}0.6cm$, and $6.9{\pm}1.0cm$, respectively. The mean distance measured between the Rf and the nasion using traditional method was $18.4{\pm}0.6cm$. Conclusion : The distance between the Rf and the nasion roughly correspond within the range of mean 4 mm compared with that measured by the traditional measurement. These data may be more helpful to delineate the Rf after the placement of drapes for craniotomy.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.4
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• pp.154-160
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• 2014

Purpose: The efficiency of an anchor plate placed during orthognathic surgery via minimal presurgical orthodontic treatment was evaluated by analyzing the mandibular relapse rate and dental changes. Methods: The subjects included nine patients with Class III malocclusion who had bilateral sagittal split osteotomy at the Division of Oral and Maxillofacial Surgery, Department of Dentistry in Ajou University Hospital, after minimal presurgical orthodontic treatment. During orthognathic surgery, anchor plates were placed at both maxillary buttresses. The anchor plates were used to move maxillary teeth backward and for maximum anchorage of Class III elastics to minimize mandibular relapse during the postoperative orthodontic treatment. The lateral cephalometric X-ray was taken preoperatively (T0), postoperatively (T1), and one year after the surgery (T2). Seven measurements (distance from Pogonion to line Nasion-Nasion perpendicular [Pog-N Per.], angle of line B point-Nasion and Nasion-Sella [SNB], angle of line maxilla 1 root-maxilla 1 crown and Nasion-Sella [U1 to SN], distance from maxilla 1 crown to line A point-Nasion [U1 to NA], overbite, overjet, and interincisal angle) were taken. Measurements at T0 to T1 and T1 to T2 were compared and differences tested by standard statistical methods. Results: The mean skeletal change was posterior movement by $13.87{\pm}4.95mm$ based on pogonion from T0 to T1, and anterior movement by $1.54{\pm}2.18mm$ from T1 to T2, showing relapse of about 10.2%. There were significant changes from T0 to T1 for both Pog-N Per. and SNB (P<0.05). However, there were no statistically significant changes from T1 to T2 for both Pog-N Per. and SNB. U1 to NA that represents the anterior-posterior changes of maxillary incisor did not differ from T0 to T1, yet there was a significant change from T1 to T2 (P<0.05). Conclusion: This study found that the anchor plate minimizes mandibular relapse and moves the maxillary teeth backward during the postoperative orthodontic treatment. Thus, we conclude that the anchor plate is clinically very useful.

• The korean journal of orthodontics
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• v.52 no.1
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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.

• Imaging Science in Dentistry
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• v.47 no.1
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• pp.1-9
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• 2017

Purpose: This retrospective study aimed to evaluate the nasopharyngeal and oropharyngeal dimensions of individuals with skeletal class II, division 1 and division 2 patterns during the pre-peak, peak, and post-peak growth periods for comparison with a skeletal class I control group. Materials and Methods: Totally 124 lateral cephalograms (47 for skeletal class I; 45 for skeletal class II, division 1; and 32 for skeletal class II, division 2) in pre-peak, peak, and post-peak growth periods were selected from the department archives. Thirteen landmarks, 4 angular and 4 linear measurements, and 4 proportional calculations were obtained. The ANOVA and Duncan test were applied to compare the differences among the study groups during the growth periods. Results: Statistically significant differences were found between the skeletal class II, division 2 group and other groups for the gonion-gnathion/sella-nasion angle. The sella-nasion-B-point angle was different among the groups, while the A-point-nasion-B-point angle was significantly different for all 3 groups. The nasopharyngeal airway space showed a statistically significant difference among the groups throughout the growth periods. The interaction among the growth periods and study groups was statistically significant regarding the upper oropharyngeal airway space measurement. The lower oropharyngeal airway space measurement showed a statistically significant difference among the groups, with the smallest dimension observed in the skeletal class II, division 2 group. Conclusion: The naso-oropharyngeal airway dimensions showed a statistically significant difference among the class II, division 1; class II, division 2; and class I groups during different growth periods.

• The Journal of the Korean dental association
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• v.11 no.11
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• pp.739-744
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• 1973

The author measured the vertical dimension and the distances from Trichion to Nasion of 825 Korean adults (414 of male, 411 of female) above 21 years of age by Willis gauge. The following results were obtained. 1) The distances from subnasale to the bottom of chin were 71.4mm in male and 68.7mm in female, and those from Trichion to Nasion were 70.4mm in male and 68.0mm in female. The former were longer than the latter, and the distances in male were longer than those in female. 2) The differences between the distances from Subnasale to the bottom of chin were 1.0mm in male and 0.7mm in female. The frequencies of percentages, in which differences between the distances mentioned above were 0±1mm, were 43.0% in male, 42.6% in female, and 42.8% in total. 3) With the matter of age and sex differences, the distances from Subnasale to the bottom of chin and those from Trichion to Nasion were increasing to 31-40 age group by age, but those had a tendency of decreasing in the late age in both sexes.

• The korean journal of orthodontics
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• v.43 no.4
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• pp.178-185
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• 2013

Objective: To standardize the facial soft-tissue characteristics of South Korean adults according to gender by measuring the soft-tissue thickness of young men and women with normal facial profiles by using three-dimensional (3D) reconstructed models. Methods: Computed tomographic images of 22 men aged 20 - 27 years and 18 women aged 20 - 26 years with normal facial profiles were obtained. The hard and soft tissues were three-dimensionally reconstructed by using Mimics software. The soft-tissue thickness was measured from the underlying bony surface at bilateral (frontal eminence, supraorbital, suborbital, inferior malar, lateral orbit, zygomatic arch, supraglenoid, gonion, supraM2, occlusal line, and subM2) and midline (supraglabella, glabella, nasion, rhinion, mid-philtrum, supradentale, infradentale, supramentale, mental eminence, and menton) landmarks. Results: The men showed significantly thicker soft tissue at the supraglabella, nasion, rhinion, mid-philtrum, supradentale, and supraglenoid points. In the women, the soft tissue was significantly thicker at the lateral orbit, inferior malar, and gonion points. Conclusions: The soft-tissue thickness in different facial areas varies according to gender. Orthodontists should use a different therapeutic approach for each gender.

• The korean journal of orthodontics
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• v.20 no.1
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• pp.87-100
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• 1990

This study was designed to compare the craniofacial structure of orthodontic patients with that of normal adult. For that purpose, 61 male and 64 female adults with normal occlusion were selected and utilizing the cephalogram that had taken under the natural head position and computerized graphic image, the special position of each anatomical structure against true horizontal and vertical reference plane was investigated. The following results were obtained. 1. The absolute special positions of each anatomic structure were calculated. 2. The inclination of Sella-Nasion plane to true horizontal plane was $8.3^{\circ}{\pm}3.9$ in male and $9.3^{\circ}{\pm}3.2^{\circ}$ in female. 3. The inclination of Frankfort horizontal plane to true horizontal plane was $1.3^{\circ}{\pm}3.0^{\circ}$ in male and $1.7^{\circ}{\pm}3.0^{\circ}$ in female. 4. The dimensions of Nasion-sella and Nasion-Anterior nasal spine to be used as the basic units of mesh diagram were $70.7mm{\pm}3.1mm$, $61.8mm{\pm}2.7mm$ in male and $67.8mm{\pm}3.3mm$, $57.0mm{\pm}2.6mm$ in female respectively. 5. The standard templates of craniofacial structure of male and female adult normal group were constructed. 6. The mesh diagrams of craniofacial structure of male and female adult normal group were constructed.

• The korean journal of orthodontics
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• v.42 no.2
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• pp.73-79
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• 2012

Objective: The purpose of this study was to investigate the effects of a newly developed rapid maxillary expansion screw-the memory screw-over 6 months. Methods: Five subjects, aged between 11.7 and 13.75 years, were enrolled in this study. All subjects underwent placement of a maxillary expansion appliance containing superelastic nickel-titanium open-coil springs in its screw bed. The parents of the patients and/or the patients themselves were instructed to activate the expansion screw by 2 quarter-turns 3 times a day (morning, midday, and evening; 6 quarter-turns a day). The mean expansion period was $7.52{\pm}1.04$ days. Dentoskeletal effects of the procedure, including dentoalveolar inclination, were evaluated. Measurements of all the parameters were repeated after 6 months of retention in order to check for relapse. Results: Sella-Nasion-A point (SNA) and Sella-Nasion/Gonion-Menton angles increased, and Sella-Nasion-B point (SNB) angle decreased in all the subjects during the expansion phase. However, they approximated to the initial values at the end of 6 months. On the other hand, the increments in maxillary apical base (Mxr-Mxl) and intermolar widths was quite stable. As expected, some amount of dentoalveolar tipping was observed. Conclusions: The newly developed memory expansion screw offers advantages of both rapid and slow expansion procedures. It widens the midpalatal suture and expands the maxilla with relatively lighter forces and within a short time. In addition, the resultant increments in the maxillary apical base and intermolar width remained quite stable even aft er 6 months of retention.