Posterior open bite / 대한치과교정학회지

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. Distinguishing 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.

Orthodontic treatment of palatally impacted canine / 대한치과교정학회지

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 localize 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 established, Properly managed impacted canine can provide funtion and esthetic through proper diagnosis and treatment of extraction of canine is not indicated.

The relationship of mandibular condylar position to overbite depth / 대한치과교정학회지

This study was designed to evaluate the relationship of mandibular condylar position to overbite depth and compare the findings from transcranial radiographs and those from individualized corrected tomographs in determination of condylar position. The subjects consisted of 20 control subjects (male 8, female 12), and 10 open-bite patients (male 3, female 7) and 23 deep-bite patients (male 17, female 6). The mean age was 23.3 years for the control group, 21.5 years for open-bite group, and 23.2 years for deep-bite group. Transcranial radiographys and individualized corrected tomographys in centric occlusion were taken from right and left temporomandibular joints of each subject. The results were as follows. 1. In the 20 normal subjects showing no symptoms of TM disorder, the incidence of condylar retrusion was 27.5%, middle condylar position 60.0%, and anterior displacement 12.5%. 2. There was significant correlation between the bite depth and observed condylar position. 3. Only 45.2% of the findings from transcranial radiographs coincided with those from individualized corrected tomographs in determining condylar position.