RADIOGRAPHIC STUDY OF ERUPTION CHARACTERISTICS FOR UPPER PERMANENT 1ST MOLAR CLASSIFIED AS IRREVERSIBLE ECTOPIC ERUPTION |
조선대학교 치과대학 소아치과학교실 |
비가역성 이소맹출로 분류된 상악 제1대구치의 맹출 특성에 관한 방사선학적 연구 |
임엘, 이상호, 이난영 |
조선대학교 치과대학 소아치과학교실 |
Correspondence:
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Received: 4 June 2009 • Accepted: 5 November 2009 |
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Abstract |
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. |
Key Words:
Ectopic eruption; The maxillary first permanent molar; Mesial angulation; The maxillary second primary molar; Root resorption |
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