• The Journal of the Korean dental association
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• v.56 no.3
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• pp.142-150
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• 2018

In the posterior maxillary area, due to resorption of the ridge after extraction and pneumatization of the maxillary sinus, the height of the alveolar ridge may not be sufficient for placement of implants. To solve this problem, sinus augmentation using both crestal and lateral approaches have been widely used. Jung et al. (2010) introduced the modified lateral approach technique, which is a simplified technique that combines the advantages of crestal and lateral approaches. The purpose of this case report is to report two cases in the posterior maxilla in which simultaneous implant placement with maxillary sinus augmentation has been performed using the modified lateral approach technique. In two female patients, 67 and 74 years old, respectively, simultaneous implant placement was performed using the modified lateral approach technique on the left maxillary second premolar and the first molar. In both patients, the residual bone height on the distal side of the maxillary second premolar was measured to be approximately 5 mm, and the residual bone height of the first molar was measured to be 2-3 mm. After flap elevation, osteotomy of the lateral window was performed in the form of a mesiodistally extended slot above the sinus floor and the Schneiderian membrane was elevated. Sequenced drilling was performed while protecting the membrane with a periosteal elevator. Bone graft and implant placement was performed after preparation of the implant site. Sufficient primary stability was achieved for each implant and sinus membrane was not perforated. After four and five months respectively, implant second surgery was performed. Clinically, the implants were observed to be stable. Implants and surrounding peri-implant mucosa were well maintained after prosthodontic treatment. In conclusion, the modified lateral approach could be a predictable and efficient technique for implant placement in the atrophied posterior maxilla.

• The korean journal of orthodontics
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• v.24 no.3 s.46
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• pp.509-519
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• 1994

Upper canine is described as 'cornerstone' of maxilla, and its importance is implicated by long root and good alveolar support. The incidence of impaction of upper canine is the second most frequent next to the third molar because it takes a long period of time to develop, and has a complicated path of eruption, and erupts lately. Generally, the patient who has a palatally impacted canine visit the clinic primarily due to a missing of canine after 12-13 years old. Palatally impacted canine is different from labially impacted canine in its cause and treatment process. It is due to malposition or anomalous lateral incisor rather than arch length deficiency. Once the impaction is identified, the first stage of the treatment is to localiz the lesion by radiographic examinations or others and according to severity, orthodontic traction, or transplantation should be considered, and comprehensive diagnosis and treatment plan of malocclusion should be estsblished. Properly managed impacted canine can provide funtion and esthetic through proper diagnosis and treatment of extraction of canine is not indicated.

• The korean journal of orthodontics
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• v.23 no.2 s.41
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• pp.165-177
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• 1993

Upper canine is important because it protects and maintains the stability of the dental arch and also, joins the anterior with the posterior teeth. The incidence of impaction of upper canine is the second most frequent next to the third molar because it takes a long period of time to develop, and has a complicated path of eruption, and erupts lately. After the age of 10, clinical and radioglaphic examination can be used in revealing the possibility of impaction and efforts should be put to reduce the side effects. To prevent impaction, selective extraction of primary canine at the age of 8 to 9 could be considered and prolonged retention of primary canine in oral cavity should be avoided at this time. Once the impaction is iden, the first stage of the treatment is to lcocalize the lesion by radiographic examination and According to the severity, orthodontic traction or autotransplantation should be considered and comprehensive diagnosis and treatment plan of malocclusion should be established. Generally, labial impaction is due to arch length discrepancy and palatal impaction is due to malposition or morphologic pathosis of lateral incisors rather than arch length discrepancy. In surgical procedure, peridontal problems should be considered and the minimum amount of bone and soft tissue should be reduced and direct bonding method of many attachment methods should be recommended. Especially in traction of labially impacted canine, it should be guided to erupt through the keratinized zone and proper forced magnitude should be applied. The importance of periodontal condition should always be in mind following the patient education to mintain the good oral hygiene at each stage of treatment. Properly managed impacted canine can provide function and esthetic by proper diagnosis and treatment if extraction of canine is not indicated.

• The korean journal of orthodontics
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• v.34 no.6 s.107
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• pp.488-496
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• 2004

The purpose of the present study was to investigate the relationship of dental crowding to tooth size and arch dimension in Korean subjects. Two groups of dental casts with Class I molar relationship, were selected on the basis of crowding. One group, consisting of 82 pairs of study cast (29 males and 53 females), exhibited at least 7 millimeters of crowding in each arch. A second group, consisting of 82 sets of study cast (37 males and 45 females), exhibited normal occlusion with little or no crowding. Mesiodistal tooth diameters, and buccal and lingual dental arch widths were measured and compared between the crowding and normal occlusion groups. Significant differences were observed between the two groups not only in arch widths but also in tooth sizes. The results of the present study suggest that both extraction and expansion can be used as a treatment approach for the crowding cases.

• The korean journal of orthodontics
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• v.49 no.6
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• pp.393-403
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• 2019

Objective: Sliding mechanics using orthodontic miniscrews is widely used to stabilize the anchorage during extraction space closure. However, previous studies have reported that both posterior segment displacement and anterior segment displacement are possible, depending on the mechanical properties of the archwire. The present study aimed to investigate the effect of archwire stiffness and friction change on the displacement pattern of the maxillary posterior segment during anterior segment retraction with orthodontic miniscrews in sliding mechanics. Methods: A three-dimensional finite element model was constructed. The retraction point was set at the archwire level between the lateral incisor and canine, and the orthodontic miniscrew was located at a height of 8 mm from the archwire between the second premolar and first molar. Archwire stiffness was simulated with rectangular stainless steel wires and a rigid body was used as a control. Various friction levels were set for the surface contact model. Displacement patterns for the posterior and anterior segments were compared between the conditions. Results: Both the anterior and posterior segments exhibited backward rotation, regardless of archwire stiffness or friction. Among the conditions tested in this study, the least undesirable rotation was found with low archwire stiffness and low friction. Conclusions: Posterior segment displacement may be unavoidable but reducing the stiffness and friction of the main archwire may minimize unwanted rotations during extraction space closure.

• Journal of The Korean Dental Society of Anesthesiology
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• v.3 no.1 s.4
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• pp.10-18
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• 2003

Background: Studies on the pain have been dealing with many different ways for last several centuries. Especially, preemptive analgesia is being used as a method to control the postoperative pain. Many studies on its efficacy have been processed in different ways about various drugs, administration methods and times for various operations. And the value of preemptive analgesia are still controversial regarding the results of other clinical studies. The authors performed a clinical study on efficacy of preemptive analgesia using an non-steroidal anti-inflammatory drug (NSAID) for the surgical extraction of impacted third molar teeth and present the more effective pain treatment after oral surgery with literature review. Methods: Using a randomized double blind test design, this study compared the analgesic efficacies of an NSAID, Talniflumate 370 mg. This drug administrated first either 1 hour preoperatively (experimental group) or when the pain developed moderately to severely over 5 scale of verbal rating scales (0-10) to respective 30 patients undergoing the removal of impacted third molars. Pain intensity and the time from the end of surgery were assessed postoperatively whenever the patients demanded additional drug over 5 scale for forty eight hours using same verbal rating scales. Results: The sex distribution, the age of the patients. and the time required for surgery in two groups were similar. The average first time for demanding additional drug after surgery was 163.9 minutes in experimental group and 191.5 minutes in control group. At this time, the average pain intensity was 5.8 in experimental group and 6.1 in control group. And the average second time for demanding additional drug was 365.5 minutes in experimental group and 351.8 minutes in control group. At this time. the average pain intensities were 6.6 in experimental group and 6.2 in control group. No statistically significant difference was found between the average first times and second times, and the average pain intensities at first and second times in two groups. Conclusions: From these results the efficacy of preemptive analgesia used in this study was not appeared. This clinical study indicates that many NSAIDs administrated preoperatively in present practices have weak efficacy of preemptive analgesia for postoperative pain, thus the authors recommend that only postoperative analgesics are adequate without preoperative use of analgesics.

• The korean journal of orthodontics
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• v.49 no.3
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• pp.161-169
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• 2019

Objective: To evaluate the effectiveness of the Frog appliance in three dimensions by using cone-beam computed tomography (CBCT) images. Methods: Forty patients (21 boys and 19 girls), averaged 11.7 years old, with an Angle Class II division 1 malocclusion were included in our study. They had either late mixed dentition or early permanent dentition, and the maxillary second molars had not yet erupted. All patients underwent CBCT before and after the treatment for measuring changes in the maxillary first molars, second premolars, central incisors, and profile. Paired-samples t-test was used to compare the mean difference in each variable before treatment and after the first phase of treatment. Results: The maxillary first molars were effectively distalized by 4.25 mm (p < 0.001) and 3.53 mm (p < 0.05) in the dental crown and root apex, respectively. The tipping increased by $2.25^{\circ}$, but the difference was not significant. Moreover the teeth moved buccally by 0.84 mm (p < 0.05) and 2.87 mm (p < 0.01) in the mesiobuccal and distobuccal cusps, respectively, whereas no significant changes occurred in the root apex. Regarding the anchorage parts, the angle of the maxillary central incisor's long axis to the sella-nasion plane increased by $2.76^{\circ}$ (p < 0.05) and the distance from the upper lip to the esthetic plane decreased by 0.52 mm (p = 0.01). Conclusions: The Frog appliance effectively distalized the maxillary molars with an acceptable degree of tipping, distobuccal rotation, and buccal crown torque, with only slight anchorage loss. Furthermore, CBCT image demonstrated that it is a simple and reliable method for three-dimensional analysis.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.709-716
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• 2008

Purpose: Autogenous transplantation of teeth can be defined as transplantation of teeth from one site to another in the same individual, involving transfer of impacted or erupted teeth into extraction sites or surgically prepared sockets". Successful autogenous transplantation of teeth depends upon a complex variety of factors. Such factors include damage to the periodontal ligament of the donor tooth, residual bone height of the recipient site, extra-oral time of tooth during surgery. Schwartz and Andreasen previously reported that autogenous transplantation of teeth with incomplete root formation demonstrated higher success rate than that of teeth with complete root formation. Gault and Mejare yielded similar rate of successful autogenous transplantation both in teeth with complete root formation and in teeth with incomplete root formation when appropriate cases were selected. This case report was aimed at the clinical and radiographic view in autogenous transplantation of teeth with complete root formation. Materials and Methods: Patients who presented to the department of periodontics, Chonnam National University Hospital underwent autogenous transplantation of teeth. One patient had vertical root fracture in a upper right second molar and upper left third molar was transplanted. And another patient who needed orthodontic treatment had residual root due to caries on upper right first premolar. Upper right premolar was extracted and lower right second premolar was transplanted. Six months later, orthodontic force was applied. Results: 7 months or 11/2 year later, each patient had clinically shallow pocket depth and normal tooth mobility. Root resorption and bone loss were not observed in radiograph and function was maintained successfully. Conclusion: Autogenous transplantation is considered as a predictive procedure when it is performed for the appropriate indication and when maintenance is achieved through regular radiographic taking and follow-up.

• The korean journal of orthodontics
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• v.34 no.5 s.106
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• pp.394-407
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• 2004

The Purpose of this study was to evaluate the effect of the lower third molar on treatment time and distal en masse movement of the lower dentition in Giass III malocclusions. Thirty subjects (9 males and 27 females) were selected, all of whom were diagnosed as Glass III malocclusion and treated by fixed appliances without premolar and/or molar extraction. They were divided into three groups Group 1 consisted of 12 subjects. whose lower third molars were not extracted during the whole orthodontic treatment. Group 2 consisted of 8 subjects. whose lower third molars were extracted after WEAW application and before removal of the orthodontic appliances. Group 3 consisted of 10 subjects whose lower third molars were extracted before MEAW application. For each subject. overall treatment time and duration of MEAW application were determined. In addition. pre-treatment and post-treatment lateral cephalometric radiographs were analyzed. All data were Processed statistically with ANOVA, and the conclusions were as follows: There was no significant difference among the groups in overall treatment time However, duration of MEAW application was longer in Group 2 than in Group 1 or Group 3. The overjet that was established after orthodontic treatment was largest in Group 3, in which the lower third molars were extracted befor MEAW application. After orthodontic treatment, IMPA decreased in Group 3. but increased in Group 1 and Group 2. There was no significant difference among the three groups in the translation of lower second molars However the tipping movement of lower second molars was significantly different, highest in Group 2 and lowest in Group 1 Therefore. it is thought to be better for the orthodontic treatment of Class III malocclusions to extract the lower third molars before MEAW application. In Group 2, the mandibular plane angle was decreased as a result of forward rotation of the mandible This skeletal change was thought to bring about the difficulty of treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.4
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• pp.390-396
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• 2012

Infraocclusion is defined as tooth whose relative occlusal movement was blocked during the period of active eruption due to ankylosis and so on. Then infraoccluded tooth remains under the occlusal plane composed by adjacent structures showing normal eruption patterns. Untreated infraocclusion may cause: prolonged retention of infraoccluded teeth; extrusion of apposed teeth; destruction of periodontal tissues by occlusal force and food packing; increased sensitivity for dental caries; and disturbances on eruption pathway of succedaneous teeth. Therefore, periodic check-ups and proper treatments are required. There are many treatment options on infraoccluded deciduous molars such as periodic observation, conservative method, restoration and space regaining with extraction of the teeth. The choice of treatment may depend on the presence of succedaneous teeth, time of diagnosis and degree of infraocclusion. In this case report, three patients showing displacement of the second premolars due to infraocclusion of upper second primary molars, were treated by means of space regaining with removable orthodontic appliances and extraction of ankylosed primary molars. All malpositioned permanent premolars in the 3 cases showed ordinary eruption pathways after treatment.