• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.576-580
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• 2003

A 7-year-old male was refered to Department of Pediatric Dentistry, Wonkwang Dental Hospital for treatment of a traumatic injury to the teeth of the maxillary anterior region of the mouth. His right central incisor presented subluxation and root fracture, the left central incisor had suffered intrusive luxation and root fracture. The initial treatment involved reposition and fixation of the teeth with 0.5mm stainless steel wire and composite resin. The patient was submitted for clinical and radiographic fallow-up. After 4 years, radiographically the right central incisor seemed to be healed by hard tissue union and showed to be indistinct fracture line, intact lamina dura. The left central incisor radiographically was healed by interposition of bone and connective tissue and showed to be distinct horizontal fracture line separating the fragments, and pulp canal obliteration. In clinical examination, the teeth showed a normal response to elective pulp test, percussion and mobility test. Pulp survival after injuries appears to be dependent upon the type of luxation injury, age of patient, stage of root development and degree of dislocation. In this case, the two teeth with incomplete root formation were suffered different type of injury by trauma and has showed different healing aspect.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.259-272
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• 1997

This study was performed to locate the anteroposterior position of the center of resistance of upper anterior teeth when intrusive forces are acted on them by applying segmented arch mechanics. Three-dimensional finite element model of upper six anterior teeth, periodontal ligament and alveolar bone was constructed The locations of the center of resistance were compared according to the three variables, which are number of teeth contained in anterior segment, axial inclination of anterior teeth, and degree of alveolar bone loss. The following conclusions were drawn from this study; 1. When the axial inclination and alveolar bone height were normal, the locations of center of resistance of anterior segment according to the number of teeth contained were as follows; 1). In 2 teeth segment, the center of resistance was located in the distal area of lateral incisor bracket 2) In 4 teeth segment, the center of resistance was located in the distal 2/3 of the distance between the brackets of lateral incisor and canine. 3) In 6 teeth segment, the center of resistance was located in 3mm distal of canine bracket, which is interproxirnal area. between canine and 1st premolar. 4) As the number of teeth contained in anterior segment increased, the center of resistance shifted to the distal side. 2. As the labial inclination of incisors increased, the center of resistance shifted to the distal side. 3. As the alveolar bone loss increased, the center of resistance shifted to the distal side.

• Journal of Yeungnam Medical Science
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• v.5 no.1
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• pp.127-133
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• 1988

Two patients, sought treatment for chief complaints of protruding frontal tooth and desired treatment to reduce the prominance of lips, were diagnosed as bimaxillary protrusion via clinical and cephalometric analysis. The authors corrected them by combined surgical and orthodonic treatment. As pre-surgical survey, paper and cast surgery were performed and wafer and resin sprint were constructed. We performed anterior maxillary and mandibular osteotomies in first premolar site to retract the maxillary and mandibular dentoalveolar segment in order to ; 1) decrease prominance of upper and lower lips. 2) create proper lower incisor intrusion. By use of intrtamaxillary fixation, prompt oral intake was possible. We made good result of esthetic improvement and there was no evidence of relapse and any complication.

• The korean journal of orthodontics
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• v.48 no.3
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• pp.189-199
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• 2018

For patients with bimaxillary protrusion, significant retraction and intrusion of the anterior teeth are sometimes essential to improve the facial profile. However, severe root resorption of the maxillary incisors occasionally occurs after treatment because of various factors. For instance, it has been reported that approximation or invasion of the incisive canal by the anterior tooth roots during retraction may cause apical root damage. Thus, determination of the position of the maxillary incisors is key for orthodontic diagnosis and treatment planning in such cases. Cone-beam computed tomography (CBCT) may be useful for simulating the post-treatment position of the maxillary incisors and surrounding structures in order to ensure safe teeth movement. Here, we present a case of Class II malocclusion with bimaxillary protrusion, wherein apical root damage due to treatment was minimized by pretreatment evaluation of the anatomical structures and simulation of the maxillary central incisor movement using CBCT. Considerable retraction and intrusion of the maxillary incisors, which resulted in a significant improvement in the facial profile and smile, were achieved without severe root resorption. Our findings suggest that CBCT-based diagnosis and treatment simulation may facilitate safe and dynamic orthodontic tooth movement, particularly in patients requiring maximum anterior tooth retraction.

• The korean journal of orthodontics
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• v.45 no.3
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• pp.121-129
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• 2015

Objective: This study aimed to assess three-dimensional changes in the temporomandibular joint positions and mandibular dimensions after correction of dental factors restricting mandibular growth in patients with Class II division 1 or division 2 malocclusion in the pubertal growth period. Methods: This prospective clinical study included 14 patients each with Class II division 1 (group I) and Class II division 2 (group II) malocclusions. The quad-helix was used for maxillary expansion, while utility arches were used for intrusion (group I) or protrusion and intrusion (group II) of the maxillary incisors. After approximately 2 months of treatment, an adequate maxillary arch width and acceptable maxillary incisor inclination were obtained. The patients were followed for an average of 6 months. Intraoral and extraoral photographs, plaster models, and cone-beam computed tomography (CBCT) images were obtained before and after treatment. Lateral cephalometric and temporomandibular joint measurements were made from the CBCT images. Results: The mandibular dimensions increased in both groups, although mandibular positional changes were also found in group II. There were no differences in the condylar position within the mandibular fossa or the condylar dimensions. The mandibular fossa depth and condylar positions were symmetrical at treatment initiation and completion. Conclusions: Class II malocclusion can be partially corrected by achieving an ideal maxillary arch form, particularly in patients with Class II division 2 malocclusion. Restrictions of the mandible in the transverse or sagittal plane do not affect the temporomandibular joint positions in these patients because of the high adaptability of this joint.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.3
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• pp.431-437
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• 2000

Traumatic intrusive luxation, an occurrence common in the primary dentition but one that occurs rarely in the permanent dentition, has a poor prognosis. There have been many treatment approaches such as allowing the tooth to reerupt spontaneously, surgical repositioning and immediate luxation, surgical luxation, and orthodontic repositioning; but all have their own drawbacks. Meanwhile, Turley et al. (1987) have proposed surgical and orthodontic combination therapy to treat intrusion. Surgical and orthodontic combination therapy means to apply the orthodontic traction force immediately after surgical luxation. If ankylosis occurs, orthodontic force may be applied after re-luxation repeatedly. But in cases of complete intrusive luxation, it would be not feasible to bond an orthodontic button or bracket on the tooth directly. Thus, in this case, traction of the tooth was attempted after surgically repositioning it close to the probable original socket site to promote better healing.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.3
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• pp.290-295
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• 2011

During tooth formation, tooth development can be affected by physical action or metabolic changes around dental follicle. Especially trauma to primary dentition is the most representative physical factor that can cause development disorders of succedaneous tooth. Enamel hypoplasia and crown discoloration of succedaneous tooth are common complications of trauma. And impaction, ectopic eruption, arrest of root formation and root dilaceration of succedaneous tooth are rare. In this case, a 6-year and 5-month-old female patient visited for dental evaluation after trauma. She was diagnosed with alveolar bone fracture near upper front teeth, extrusion of the upper right and left primary central incisors, intrusion of the upper right primary lateral incisor, and palatal luxation of the upper left primary lateral incisor. Upper right and left primary central incisors with severe mobility were extracted, with gingival suture on the day of the visit. During 24 months check up, root dilacerations were found near the cemento enamel junction in the upper lateral incisors and arrests of root formation were found on the coronal 1/3 of the root in the upper central incisors. Although alveolar bone fracture is rare type of trauma in children, a thorough examination of alveolar bone is essential for prognosis and following treatment in patients with trauma.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.241-251
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• 1992

The purpose of this study was to investigate the root resorption pattern in incisors in dog under intrusive orthodontic loadings of various magnitude and duration. Intrusive forces were generated by closed coil springs. Force magnitudes were 15-30gm, 50-60gm and 80-110gm. Durations were continuous and intermittent. Intermittent duration was applied at intervals of 12 hours. The readjustment of the force was done every 4 days. The forces were maintained for 30 days. All specimens were decalfied, embedded in paraffin and stained with hematoxylin-eosin stain. Observations were made with light microscope. The following results were obtained; 1. The continuity of root surface was ceased in all, except intermittent forced teeth with 25gm. 2. The root resorptions, cementoclasts and cemental lacunae, were increased around periapical regions and the destructive scope of bone was deeply extended as the exerted orthodontic forces increased. 3. It was inspected that, under the same forces, root resorption and bone destruction were more deeply appeared in the continuously forced teeth than the intermittently forced ones. 4. All of the alveolar bone, showed direct and undermining bone resorptions.

• The korean journal of orthodontics
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• v.51 no.4
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• pp.293-300
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• 2021

In this report, we demonstrate the effectiveness of the Invisalign^® system in the treatment of severe gingival recession and bone dehiscence through torque, translation, and intrusion movements in a young woman. Cone-beam computed tomography was used to assess bone parameters and check the teeth during treatment. The root of the mandibular right central incisor, which was buccally positioned and exhibited bone dehiscence of 9.4 mm, was moved toward the center of the alveolar process by using the Invisalign^® system and SmartForce^® features. The patient was monitored by a periodontist throughout the orthodontic treatment period. Her gingival recession reduced, while the bone dehiscence reduced from 9.40 mm to 3.14 mm. Thus, movement of the root into the alveolus promoted bone neoformation and treated the gingival recession. The findings from this case suggest that orthodontic treatment using the Invisalign^® system, along with periodontal monitoring, can aid in the treatment of gingival recession and alveolar defects.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.3
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• pp.522-528
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• 2006

When tooth is displaced within the alveolar bone, it could apply pressure and rupture the apical vessels. Pulpal reaction in such case is affected by the stage of root formation, amount of intrusion and pulpal infection. Determining the need of pulp treatment depends on the pulp vitality. Therefore, periodic vitality tests, coronal color changes and radiographic root resorption signs should be observed through periodic post-trauma follow-up. Pulp necrosis, pulp canal obliteration, external root resorption, root ankylosis and marginal bone loss could result from periodontal injuries. Negative sign changes from positive signs of vitality tests suggest pulp necrosis. In this case, pulp treatment should be held before root resorption occurs. By comparing the following two cases, complications of intrusion and factors producing them could be confirmed, thus we propose to report these two cases.