• The korean journal of orthodontics
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• v.31 no.6 s.89
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• pp.549-558
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• 2001

This study was undertaken to demonstrate the forces in the maxillary alveolar bone generated by the activation of the maxillary posterior crossbite appliance In the treatment of posterior buccal crossbite caused by buccal ectopic eruption of the maxillary second molar. A photoelastic model was fabricated using a Photoelastic material (PL-3) to simulate alveolar bone and ivory-colored resin teeth. The model was observed throughout the anterior and posterior view in a circular polariscope and recorded photographically before and after activation of the maxillary posterior crossbite appliance. The following conclusions were reached from this investigation : 1. When the traction force was applied on the palatal surface of the second molar, stresses were concentrated at the buccal and palatal root apices and alveolar crest area. The axis of rotation of palatal root was at the root apex and that of the buccal root was at the root li4 area. In this result, palatal tipping and rotating force were generated. 2. When the traction force was applied on the buccal surface of the second molar, more stresses than loading on the palatal surface were observed in the palatal and buccal root apices. Furthermore, the heavier stresses creating an intrusive force and controlled tipping force were recorded below the buccal and palatal root apices below the palatal root surface. In addition, the axis of rotation of palatal root disappeared whereas the rotation axis of the buccal root moved to the root apex from the apical 1/4 area. 3. When the traction force was simultaneously applied on the maxillary right and left second molars, the stress intensity around the maxillary first molar root area was greater than the stress generated by the only buccal traction of the maxillary right or left second molar. As in above mentioned results, we should realize that force application on the palatal surface of second molars with the maxillary posterior crossbite appliance Produced rotation of the second molar and palatal traction, which nay cause occlusal Interference. That is to say, we have to escape the rotation and uncontrolled tipping creating occlusal interference when correcting buccal posterior crossbite. For this purpose, we recommend buccal traction rather than palatal traction force on the second molar.

• The korean journal of orthodontics
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• v.31 no.6 s.89
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• pp.559-566
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• 2001

This study was undertaken to demonstrate the forces in the mandibular alveolar bone generated by activation of the mandibular posterior crossbite appliance in the treatment of buccal crossbite caused by lingual eruption of mandibular second molar. A three-dimensional photoelastic model was fabricated using a photoelastic material (PL-3) to simulate alveolar bone. We observed the model from the anterior to the posterior view in a circular polariscope and recorded photogtaphically before and after activation of the mandibular posterior crossbite appliance. The following results were obtained : 1. When the traction force was applied on the buccal surface of the mandibular second molar, stress was concentrated at the lingual alveolar crest and root apex area. The axis of rotation also was at the middle third of the buccal toot surface and the root apex, so that uncontrolled tipping and a buccal traction force for the mandibular second molar were developed. 2. When the traction force was applied on the lingual surface of the mandibular second molar more stress was observed as opposed to those situations in which the force application was on the buccal surface. In addition, stress intensity was increased below the loot areas and the axis of rotation of the mandibular second molar was lost. In result, controlled tipping and intrusive tooth movements were developed. 3. When the traction forte was applied on either buccal or lingual surface of the second molar, the color patterns of the anchorage unit were similar to the initial color pattern of that before the force application. So we can use the lingual arch for effective anchorage in correcting the posterior buccal crossbite. As in above mentioned results, we must avoid the rotation and uncontrolled tipping, creating occlusal interference of the malpositioned mandibular second molar when correcting posterior buccal crossbite. For this purpose, we recommend the lingual traction force on the second molar as opposed to the buccal traction.

• The korean journal of orthodontics
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• v.44 no.3
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• pp.143-153
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• 2014

An 8-years old boy with facial asymmetry and unilateral posterior crossbite on the left side received orthopedic and orthodontic treatment. During the first phase of treatment, the narrow maxillary arch was expanded using an acrylic plate. Then, the acrylic plate was used as a bite block with occlusal indentations from the construction bite that was obtained with the incisors in a coincident dental midline. After the position of the mandible was stabilized, the second phase of orthodontic treatment was initiated using fixed appliances for detailing of the occlusion. Skeletal symmetry, ideal occlusion, and coincident dental midlines were thus achieved. Functionally, occlusal force balance and masticatory muscle activity were improved, and the chewing patterns were normalized.

• The korean journal of orthodontics
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• v.31 no.6 s.89
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• pp.611-618
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• 2001

This is a case report of a 12.5-year-old girl who presented with moderate to severe anterior dental crowding and rotations. Treatment involved no extraction, but expansion of both the maxillary and the mandibular arches. Maxillary expansion was assisted by rapid palatal expansion despite the fact that this patient did not present with posterior crossbite. Crowding and rotations in both arches were corrected and good occlusal function and improved facial esthetic were achieved, with acceptable overbite and overjet. The application of rapid maxillary expansion in cases with no posterior crossbite, which has increased in recent years, calls for re-evaluation of the diagnostic basis and indications for the use of this technique.

• The Journal of the Korean dental association
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• v.35 no.2 s.333
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• pp.80-81
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• 1997

• The Journal of the Korean dental association
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• v.35 no.3 s.334
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• pp.140-141
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• 1997

• Journal of Technologic Dentistry
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• v.16 no.1
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• pp.122-125
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• 1994

• The Journal of the Korean dental association
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• v.16 no.4 s.107
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• pp.279-282
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• 1978

A girl aged 16 years and I month, had a severe Angle's class III malocclusion, characterized by a retarded and constricted maxilla, anterior and posterior crossbite. This patient underwent extraction of two lower Ist premolar. After extraction, author placed multibanded system in lower dental arch to change the long axis of anterior teeth and delivered removable appliance with Coffin spring in the upper dental arch to expand dental arch. After 13 months, anterior & posterior crossbite was corrected and this patient's profile was improved. Superimposition of pretreatment and posttreatment cephalograms upon the SN line registered at S showed backward downward rotation of the mandible and retrusion of lower lip.

• The Journal of the Korean dental association
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• v.16 no.4 s.107
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• pp.273-278
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• 1978

A girl aged 16 years and I month, had a severe Angle's class III malocclusion, characterized by a retarded and constricted maxilla, anterior and posterior crossbite. This patient underwent extraction of two lower Ist premolar. After extraction, author placed multibanded system in lower dental arch to change the long axis of anterior teeth and delivered removable appliance with Coffin spring in the upper dental arch to expand dental arch. After 13 months, anterior & posterior crossbite was corrected and this patient's profile was improved. Superimposition of pretreatment and posttreatment cephalograms upon the SN line registered at S showed backward downward rotation of the mandible and retrusion of lower lip.

• The korean journal of orthodontics
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• v.27 no.6 s.65
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• pp.1005-1010
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• 1997