• The korean journal of orthodontics
• /
• v.53 no.4
• /
• pp.276-285
• /
• 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.

• The korean journal of orthodontics
• /
• v.27 no.2
• /
• pp.297-313
• /
• 1997

The purposes of this study were to compare the soft tissue changes following hard tissue change after surgery between the one jaw and two-jaw surgery in skeletal class III patients and to get the reference of the incisal inclination at presurgical orthodontics. For this study 24 patients for the two-jaw surgery group and 18 patients for one jaw surgery group were selected. Lateral cephalograms were taken at pretreatment, after presurgical orthodontic treatment, immediately after surgical treatment and at least 6 months after surgery. They were traced and analyzed on skeletodental structure and soft tissue. The results were as follows: 1. After surgery, maxilla, maxillary incisors and upper lip were moved anteriorly and superiorly in two-jaw surgery group. Mandible and mandibular incisors were moved posteriorly and superiorly, and thickness of lower lip was increased in both group but there were no statistically significant difference. Anterior facial height was more decreased in two-jaw surgery group (p<0.05). At least 6 months after surgery, by the postorthodontic treatment, maxillary incisors were moved labially 1.44mm, mandible and mandiibular incisors were moved lingually 1.43mrn, 1.26mm respectively in one jaw surgery group. But there was no statistically significant changes of hard tissue in two :jaw surgery group. 2. The correlation coefficients of maxillary hard and soft tissue horizontal changes were high in two jaw surgery group and the ratios for soft tissue to A point were 19% at Sri, 80% at SLS, 82% at LS. The ratios for soft tissue to B point were 92% at LI, 104% at ILS in one jaw surgery group, 89% at LI, 101% at ILS in two-jaw surgery group. 3. The correlation coefficients and change ratios of mandibular incisors and LL HS on lower lip horizontal changes were 0 0.89 and 75%, 85% in one jaw surgery group, 0.93, 0.90 and 76%, 87% in two-jaw surgery group. The correlation coefficients of maxillary incisors and Sn, SLS and LS on upper lip horizontal changes were 072, 0.76 and 0.75 in two jaw surgery group and ratios of changes were 57%, 58% and 59%. 4. The regression equations between skeletal horizontal discrepancy and incisal inclinaton were taken in one jaw surgery group. Those were FMIA=57.48-2.17ANB, U1-SN=-75.02+2.17SNB and $R^2$ were 0.63, 063 respectively. So if there is skeletal horizontal discrepancy by mandibular prognathism in one jaw surgery case, we consider attaining more labial inclination of maxillary incisors than normal and more lingual inclination of mandibular incisors than normal. But correlation coefficient of the regression equations in two jaw surgery group was low, so, that equation was not reliable.

• The korean journal of orthodontics
• /
• v.15 no.2
• /
• pp.369-376
• /
• 1985

A 10 year & 11 month old girl patient who had Angle's Class III malocclusion were treated by chin cap and fixed appliances. The treatment results obtained were as to]lows: 1. The anterior crossbite was corrected. 2. The functional overbite & overjet were established. 3. The favorable molar relationships were achieved. 4. The forward growth of the mandible was restrained. 5. The axial inclination of the upper & lower incisors were changed and the upper dental arch length was increased. 6. The facial profile was improved resulting from the good upper & lower jaw relations. 7. There was no harmful changes on the teeth S the periodontal tissues after treatment. 8. The good occlusal stability was showed after 1 year of retention.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.31 no.2
• /
• pp.290-298
• /
• 2004

In children, change in lifestyles such as an increase in participation of physical activities has increased the chance of receiving an injury, harming the child and their parents. This study was carried out to give basic information of traumatic injuries to the upper anterior teeth which can be used in prevention of future complications that may arise. From June, 2002 to May, 2003, of the 8,799 children in their primary and mixed dentition visiting Department of Pediatric Dentistry, College of Dentistry, Yonsei University 955 upper anterior teeth(primary 543, permanent 412) of 487 children(male 316, female 171) with traumatic injures to the upper incisors were studied. The results were as follows: 1. Trauma to the primary teeth prevailed at the age of 1-3 and to the permanent teeth at the age of 7. The male to female ratio was 1.85:1. 2. Trauma to the upper incisors for both the primary and permanent teeth occurred in the afternoon. Primary teeth were injured most frequently in the home(44.1%) and the permanent teeth outdoors, in the street(17.5%). 3. Both the primary and permanent teeth were most injured by fall-down injuries(39.8%, 12.9%), and next were collisions(22.2%, 6.0%). For the primary teeth, high fall, traffic accident, violence and sports are next in order, and for the permanent teeth, violence, sorts, traffic accidents were next. 4. Average number of 1.6 primary teeth and 2.8 permanent teeth were injured with the right central incisor most prevailing. 5. Crown fracture without pulpal exposure and subluxation injures were highest in frequency in both the primary and permanent teeth.

• The korean journal of orthodontics
• /
• v.28 no.3 s.68
• /
• pp.431-440
• /
• 1998

While periodontal disease results in the extrusion of upper incisors with interdental spacing in adult patient, the intrusive movement should be executed for the rehabilitation in terms of esthetics and function. The present study was peformed to investigate the periodontal response following orthodontic intrusion of teeth with infrabony pocket. Bone defect and periodontal disease were produced adjacent to the both maxillary second lateral incisors in four adult dogs. Four weeks later, a flap operation was performed to eliminate inflammation and a reference notch was made on the root surface at the level of bottom of each defect. Two weeks after periodontal surgery, 4 weeks of intrusion and subsequent another 4 weeks of retention was executed on the right side of incisors while left incisors served as the control. Through the histologic analysis, following results were obtained. 1. Histologic section of control side showed the reduction of pocket depth after flap operation. However, the status of long junctional epithelium was observed while new connective tissue attachment occurred in a small area adjacent newly formed cementum 2. Epithelial attachment was less around the intruded incisor while new connective tissue attachment was much more compared to the control side. 3. Plenty of cells were observed in the connective tissue around the reference notch of the intruded incisor and the degree of the new cementum formation was higher in the intruded incisor than the control. The results of the present study suggested that an orthodontic intrusion of periodontally involved and extruded incisors could be carried out with a desirable periodontal response, provided that inflammation is under control.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.35 no.4
• /
• pp.244-252
• /
• 2019

Proper positioning of maxillary incisors is key to success of surgery combined treatment. Establishing surgery plan would be a difficult job if maxillary incisors are lost. Patient who lost all of her maxillary incisors due to accident came for orthodontic treatment. Through careful modification of maxillary archform, pre-surgical orthodontic treatment was conducted with four prosthetic space consolidation. Position of incisors was decided by help of 3D prosthetic set-up, and 1-jaw surgery was planned. After relative short treatment period of 28 months, final prosthesis was done. When alveolar bone loss happens, harmonious prosthesis of upper incisors is difficult. Utilizing mandibular set-back surgery and incisor positioning using 3D set-up could make a better environment for treatment outcome. Strategic pre-surgical orthodontic treatment can allow shorter time and less number of prosthetics.

• The korean journal of orthodontics
• /
• v.26 no.6
• /
• pp.647-655
• /
• 1996

In discussing the effects of adenoids on the development of the face and dentition, it is important to note their influence on the mode of breathing and to relate this to specific facial types and dentition. This study, therefore, assumed that the ability to adapt to individual's neuromuscular complex is various. And tried to investigate the effects of reduced nasal respiratory function on the development of dentition by facial type. This paper is based on children patients with enlarged adenoids and comparing them to data taken from a control group with normal respiratory function. Among the three facial types, the most statistical significant difference was observed from dolichofacial type between experimental and control group. In dolichofacial type, the experimental group showed labioversion of upper incisor, decrease in the width of upper arch, increase in overjet, increase in the rate of cross-bite, and increase in the height of palatal vault. No significant difference was observed between the two groups in the inclination of upper and lower incisors in mesofacial type, but the experimental group was observed to show decrease in the width of upper arch and increase in the height of palatal vault. On the other hand, in brachyfacial type, no significant difference was observed between the two groups in dentition variables except showing linguoversion of upper incisor. The results, which were observed in dolichofacial type, consist with Nordlund's theory of Compression.

• The korean journal of orthodontics
• /
• v.27 no.5 s.64
• /
• pp.697-709
• /
• 1997

This study was designed to investigate the stress intensity and distribution produced by 1mm activation of retraction archwire with $0^{\circ},\;7^{\circ},\;14^{\circ}$ torque and application of high polk J-hook headgear during retraction of four maxillary incisors using the photoelastic stress analysis. The photoelastic model was made with a PL-3 type epoxy resin which was substituted by alveolar bone portion. Each retraction archwire was fabricated from .020' X .025' stainless steel wire which had vertical loops in 7mm height and hooks for high pull J-hook headgear between central and lateral incisors. The high pull J-hook headgear was applied 35 degree backward and upward to occlusal plane with 200gm pet each side The findings of this study were as follows: 1. In case of $0^{\circ}$ torque, the stress was distributed from cervical 1/8 to apex of roots of central and lateral incisors which were the forms of arc mode. When the high pull J-hook headgear was applied, the stress distributed by arc mode was presented from cervical 1/2 to apex of roots of central and lateral incisors. And the stress distributed by following the root surface was presented from alveolar crest to cervical 1/2 of roots of central and lateral incisors. The stress between apecies of central and Lateral incisors was presented also. 2. In case of $7^{\circ}$ torque, the stress distributed by arc mode was presented from cervical 1/2 to apex of roots of central and lateral incisors. And the stress distributed by following the root surface was presented from alveolar crest to cervical 1/2 of roots of central and lateral incisors. When the high pull J-hook headgear was applied, the stress distributed by following the root surface was presented mote apically than without headgear. The stress between apecies of central and lateral incisors was presented also. 3. In case of $14^{\circ}$ torque, the stress distributed by following the root surface was Presented from alveolar crest to apex of roots of central and lateral incisors. When the high pull J-hook headgear was applied, the stress distributed by following the root surface was presented stronger than without headgear The stress between apecies of central and lateral incisors was presented also.

• The korean journal of orthodontics
• /
• v.7 no.1
• /
• pp.41-46
• /
• 1977

A boy (Hellman dental age III B) with mandibular prognathism was treated by means of the labiolingual appliance and the chin cap. Following results were obtained; 1) Except the problem of development, most of treatment objectives were achieved after 8 months of active treatment. 2) The axial inclinations of upper and lower incisors were changed by the treatment. 3) The most notable change was the reduction of genial angle. 4) The patient has retained the good occlusal stability till after 18 months of retention.

• The Journal of the Korean dental association
• /
• v.10 no.3
• /
• pp.155-158
• /
• 1972

As a factor of dentistry, the form of the tooth especially the size plays an important part. And in orthodontics the relation between the tooth size, arch length and the basal arch is regarded important, and it is closely related to the extraction and retension probolem in treatment planning. The auther's study of the mesio-distal crown diameters of permanent teeth, width and length of the dental arch and basal arch from the cast of 50 men and 53 women who could be measured clerly, among 102 men and 107 women regarded as the normal occlusion showed the followings. 1. Table 1 and table 2 showed the measurement of the mesio-distal maximum width of the permanent teeth, width and length of the dental arch and basal arch of the upper and lower dentitions. 2. Men's mesio-distal width of the teeth, arch length and arch width of the upper and the lower dentition, basal arch width and basal arch length are larger than those of wonen's 3. We compared the Koreans with the American white. Upper central incisors, upper first molars and lower second premolars of the latter were larger than those of the former. And the Koreans's rest tooth of the rest were comparatively larger.