A frontal cephalometric study on the reference lines to assess the craniomaxillofacial asymmetry / 대한치과교정학회지

This study was undertaken to investigate the midline having the least difference between the right and left structures among the lines that had been used in the study of the craniomaxillofacial asymmetry. The sample of this study consisted of twenty six Korean girls(average 18.9 years old) having normal facial appearance and occlusion. On the frontal cephalometric films of the sample, we divided the whole craniomaxillifacial area into four portions, i.e., cranial, upper facial, lower facial, and dental portion. So, we have found the midlines having the least difference in the whole craniomaxillofacial area itself, and in the each divided four portions, furtherly in the other portions from aimed portion. The findings were as follow: 1. In the whole craniomaxillofacial area, the connecting line between crista galli and anterior nasal spine and the perpendicular bisecting line between right and left foramen rotundums were suitable for the midline. 2. In the cranial portion, established all six lines were suitable for midlines. In the other portions, the perpendicular bisection line between both condylion, the line passing the contact point between right and left mandibular central insisiors among the perpendicular lines between right and left mandibular central incisial tips were suitable midlines for evaluating the asymmetry of cranial portion. 3. In the upper facial portion, the perpendicular bisecting line between right and left zygions was the most suitable midline. In the other portions, the line between the crista galli and the most superior point of the odontoid process, the perpendicular bisecting line between right and left gonions, the perpendicular bisecting line between right and left condylions, and perpendicular bisecting line between right and left foramens rotundum were suitable midlines for evaluating the asymmetry of the upper facial portion 4. In the dental portion, the perpendicular bisecting lines between right and left buccal cusps of both maxillary first molars and between right and left mandibular first molars were suitable midlines. In the other portions, the perpendicular bisecting line between right and left landmarks crossing the lesser wing of the sphenoid bone and orbit, the perpendicular bisecting line between right and left mental foramens, and the connecting line between crista galli and prosthion were suitable midlines for evaluating the asymmetry of dental portion. 5. In the lower facial portion, the perpendicular bisecting lines between right and left condylions and between right and left gonions were suitable midlines. In the other portions, the line between the crista galli and anterior nasal spine, the perpendicular bisecting line between right and left foramen rotundums, and the perpendicular bisecting lines between right and left buccal cusps of both mandibular first molars and between right and left maxillary first molars were suitable midlines for evaluating the asymmetry of the lower facial portion.

A comparative study about the position of upper and lower jaws, and first molars in normal occlusion and Angle's Class I,II,III malocclusions / 대한치과교정학회지

There has been so much controversies about the position of upper and lower jaws, and their first permanent molars in normal occlusion and Angle's class I,II,III malocclusions. So, the purpose of this study is to compare the position of upper and lower jaws, and their first molars in normal occlusion and Angle's class IIIIII malocclusions by lateral cephalometric analysis. The sample consisted of one hundred and twenty girls(thirty in each group) who had completed growth. The findings of this study were as follows: 1. In class I malocclusion, both maxilla and mandible were slightly posterior position than normal occlusion, but they showed harmonious relationship. 2. In class II malocclusion, the mandible was greatly retruded, and the maxilla was also slightly retruded to the cranial base as compared with normal occlusion. 3. In class III malocclusion, the maxilla was significantly retruded to the cranial base, but no significant difference was found in mandibular position as compared with normal occlusion. 4. The maxillary first molar was located at posterior position in class II malocclusion, and anterior position in class III malocclusion to the cranium, so that the rotation of mandible was influenced by that. 5. The mandibular first molar showed constant relationship to the mandible in all four groups, but different position to the cranial base in direct proportion to the mandibular position. 6. On the treatment planning of class II malocclusion, it seems to be better to promote the mandibular horizontal growth by inhibiting the vertical growth of maxillary molar area, and on the treatment planning of class III malocclusion, it seems to be better to promote the antero-inferior growth of maxilla and to promote the mandibular vertical growth by inducing the vertical growth of maxillary molar area.

A study on the possibility of bacteremia in patients undergoing orthodontic treatment with fixed appliance / 대한치과교정학회지

The purpose of this study was to investigate a possibility of chronic or intermittent bacteremia in patients undergoing orthodontic treatment with fixed orthodontic appliance. Orthodontic patients who had been injured by orthodontic appliances and/or suffered from gingivitis were selected. They had not taken any antibiotics for 1 month. The number of subjects were 21 including 7 males and 14 females. Blood samples of the subjects were cultured and, IgG, IgA and IgM levels in the serum were quantified. The author found following results. 1. No bacterial growth was found in 7-day culture of all the samples. 2. The immunoglobulin levels in serum were confined in normal range. 3. This study could not deny the possibility of transient bacteremia episode undergoing orthodontic treatment.