• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.2
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• pp.185-189
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• 2011

Tooth impaction represents the stop of eruption by clinical and radiographical disturbance in eruption path or the dislocation of tooth germ. The most common factor in tooth eruption disorders are spacial deficiency with other causes reported to be odontogenic tumors, periodontal ligament injury, etc. Impaction of the mandibular second molar is relatively rare and reported in about 3 out of 1,000 people. Because the second molars tend to erupt in a mesial direction, this situation can lead to serious problems if untreated, including dental caries, periodontal disease and root resorption of the first molar. Treatment of this problem includes, surgical repositioning and orthodontic forced eruption. Because each procedure have the definite advantages and disadvantages, and influenced by circumferential environment, these have limits for successfu1 recovery as independent treatment. In a case at St. Mary's Hospital, we performed successful correction of a horizontal impacted mandibular second molar using a miniplate skeletal anchorage system. We introduce this treatment as a valid method for an impacted second molar and consider a oromaxillofacial surgeon's role in tooth movement treatment.

• The korean journal of orthodontics
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• v.25 no.5 s.52
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• pp.641-654
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• 1995

The purpose of this report is to present the cause and treatment of posterior open bite. Posterior open bite is the open bite limited to posterior teeth. These problem usually are attributed to a mechanical interference with the eruption process, either ankylosis or some soft tissue interference. But, in some patient, lateral open bite is due to a disturbance of the eruptive mechanism itself and other disease or side effect following other treatment. Distinguising cause of posterior open bite, lack of eruption due to some external interference with eruption or primary failure of eruption mechanism, is important clinically because this determines the prognosis for orthodontic treatments. The characteristics, differential diagnosis with posterior open bite due to other etiologies and the treatment of these problems are presented and discussed,.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.2
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• pp.219-227
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• 2020

Tooth eruption involves a complex developmental process of tooth migration from the dental follicular origin to the final occlusion position in the oral cavity via the alveolar process. Disturbance of tooth eruption can occur at any point in a series of eruption stages; however, horizontal impaction of the mandibular first molar and primary retention of the primary mandibular second molar are rarely observed simultaneously. This study describes the treatment for two cases of horizontally impacted first molar with primary retention of primary molar. The primary retention of the primary mandibular second molar was extracted, and orthodontic traction was applied to the horizontally impacted primary mandibular first molar. Subsequently, displacement of the premolar tooth bud was improved and space regaining for eruption was achieved, guiding to normal eruption of the first molar.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.2
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• pp.229-236
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• 2021

Eruption disturbances of the mandibular first molars can cause multiple problems in occlusal development although they are extremely rare. Early diagnosis and treatment are very important to prevent complications associated with eruption disturbances. The present case report describes the treatment of two cases of eruption disturbances of the mandibular first permanent molar. A fixed appliance composed of a cantilever spring with mandibular second deciduous molar as an anchor tooth was used to tract the impacted mandibular first permanent molar. The success of both cases shows that this novel traction appliance can be used to induce the eruption of an impacted mandibular first permanent molar within a short time in patients with intact mandibular second deciduous molar as an anchor tooth.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.4
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• pp.385-390
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• 2011

When many factors involved in the eruption of the teeth act as negative effects, they can cause eruption disturbance. Periodic observation, space acquirement, surgical exposure, orthodontic traction, orthodontic traction accompanied with surgical exposure, and surgical repositioning are considered as the treatment options of an impacted tooth, which is a form of eruption disturbance. In the first case, a male patient, age 9, visited Yonsei University Dental Hospital (YUDH) with a chief complaint of ectopic impaction of the upper left lateral incisor. We extracted the upper left primary lateral incisor and primary canine, and 5 months later, a window opening procedure was executed. Eight months later, the upper left lateral incisor partially erupted, and 18 months after the extraction, the axis of the tooth improved and the tooth erupted spontaneously. In the second case, a male patient, age 10, visited YUDH with a chief complaint of ectopic impaction of the upper right first premolar. We extracted the upper right first primary molar. Ten months later, the upper right first premolar erupted partially, and 19 months after the extraction, the upper right first premolar erupted spontaneously. We reported two cases in which improvement of eruption path and spontaneous eruption of an ectopic impacted tooth was achieved by extracting the deciduous tooth which interfered with the proper eruption of it.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.107-111
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• 2011

In World War II, the solar eruption (solar flare) was revealed to make a significant effect to radar systems. The radio disturbance in February 28, 1942 was due to increased cosmic ray during solar maximum. Since such phenomena had been disclosed, many studies were accomplished on solar flare and solar particle event. Now various researches about the effects of solar flare on the spacecrafts, the airplanes flying across the pole, the radar systems, and wireless communication systems are studied. In this paper we analyzed the relationship between the harmful effect on the wireless communication by the solar eruption and the period of solar activity from the sunspot number data and the solar radio burst data for last 40 years.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.490-497
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• 2007

Odontoma is defined as a benign odontogenic tumor containing enamel, dentin as well as cementum and constitued 22% of all odontogenic tumors. Although the lesions are commonly asymptomatic, they may be discovered routine radiographic examination. Odontomas often cause disturbances in the eruption of teeth such as, impaction or delayed eruption, retention of primary teeth, or abnomalities in the position of the teeth such as tipping or displacement of adjacent teeth. Radiologically, odontomas manifest as a dense radiopaque lesion surrounded by a thin radiotransparent halo. However, in some cases, radiopacity was not quite clear and images of the teeth shadowed very tiny odontomas. And at early development stages of odontoma, calcification remains immature and is difficult to diagnose on radiographs. This suggests that when delayed eruption of the teeth is found, periapical radiographs should be taken to clarify whether any small area of radiopaque material exists. This case report shows tiny odontomas involving an impacted tooth and crowding and we remove the tiny odontoma surgically.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.556-562
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• 2009

Ectopic eruption of the maxillary first permanent molar means that the molar erupts out of the normal position and is arrested in its eruption by the second primary molar. This local eruption disturbance results in a premature atypical resorption on the distal part of the second primary molar. In most irreversible cases, the second primary molar is lost prematurely, either by spontaneous exfoliation or by extraction, In cases of doubt as to whether the eruption is of the irreversible type or not, careful radiographic observation period for a few months would be valuable in evaluating the possibilities of the tooth's freeing itself. The purpose of this study was to determine the characteristics and occurrence of the ectopic eruption of the maxillary first permanent molar. A descriptive, observational, retrospective study was done using the radiographs of 25 conseutive patients, who were in the first phase of mixed dentition. A method was designed to evaluate the amount of pathologic resorption of the second maxillary primary molar and the mesial angulation of the first permanent molar. The study showed that the most important etiologic factor was the eruption path or mesial angulation of the first permanent molars relative the chosen reference lines.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.3
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• pp.590-596
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• 1997

Ankylosis is defined as a fusion of alveolar bone with dentin and/or cementum and may occur at any time during or following active eruption. Ankylosed teeth maintain existing occlusal levels while adjacent teeth continue to erupt via deposition of alveolar bone. This may result in the clinical appearance of depression or submergence of ankylosed teeth below the occlusal plane. It is found more frequently in children of late mixed dentition and in mandibular primary molars. The problems arising from ankylosed teeth, due to their submerged positions, are elongation of the antagonist, tipping of the adjacent teeth, loss of arch length, food impaction and subsequent destruction of periodontal tissue, disturbance of succedaneous tooth eruption. The author observed several cases of ankylosed primary molars and properly managed. Following results were obtained. 1. Severe infraoccluded ankylosis results in loss of arch length and undesirable effect on eruption path of succedaneous tooth, therefore early diagnosis and management are important. 2. The teeth without problems may be examined periodically and restored in order to maintain the normal occlusal function.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.98-102
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• 2000

Ectopic eruption is out of a normal position by local eruption disturbance in the developing permanent molar. The prevalence of ectopic eruption is reported to be the between 2 and 6%, most often associated maxillary first permanent molar whereas, the occurrence for the mandibular is quite rare. The etiologic factors of ectopic eruption are inadequate arch length, lack of growth in the posterior region of the jaw, mesially inclined eruption path of first permanent molars, abnormally large first permanent molars, hereditary factor and a stainless steel crown which has been improperly restored. Ectopic eruption can be treated by the use of brass wire, separating elastics, distal disking and Humphrey appliance and the use of removable appliance and cervical traction headgear after extraction of the second primary molar. This case was that lower right first permanent molar was mesially tilted state by locking on the stainless steel crown of a lower right second primary molar. The stainless steel crown was removed and Humphrey appliance was set. Like this case, ectopic eruption could be happened by the stainless steel crown which improperly restored. In restoration of the stainless steel crown, selection of proper size, trimming and contouring are very important.