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Biomedical subjects

Shin-Jae Lee

Publications and source records attributed to Shin-Jae Lee.

4 recordsLinked to original sources
PubMed2006

Correction of deep overbite and gummy smile by using a mini-implant with a segmented wire in a growing Class II Division 2 patient.

A boy, aged 10.5 years, with a Class II molar relationship and a very deep overbite, complaining of a gummy smile and anterior crowding, was treated nonextraction with a mini-implant and Twin-block and edgewise fixed appliances. Severely extruded and retroclined maxillary incisors were intruded and proclined with a nickel-titanium closed-coil spring anchored to a mini-implant and segmented wires; this resolved the gummy smile and deep overbite efficiently without extruding the maxillary molars or opening the mandible. The mandibular incisors were proclined without direct orthodontic force during intrusion of the maxillary incisors; this helped the nonextraction treatment of mandibular incisor crowding. The Twin-block appliance with high-pull headgear promoted mandibular growth, restrained maxillary growth, and changed the canine and molar relationship from Class II to Class I. The patient's overbite and overjet were overtreated, and, 1 year postretention, the patient maintained a good overbite and overjet.

Cephalometry↗
PubMed2006

Transverse implications of maxillary premolar extraction in Class III presurgical orthodontic treatment.

INTRODUCTION: Maxillary premolars are often extracted to resolve incisor proclination in presurgical orthodontic treatment for severe skeletal Class III patients. The aim of this article was to compare arch-width changes and orthodontic tooth movements between maxillary premolar extraction and nonextraction modalities, and to provide an additional indication for presurgical maxillary premolar extraction according to the transverse dental arch characteristics of Class III surgical-orthodontic patients. METHODS: Pretreatment and posttreatment dental casts of 55 adult Class III patients (24 nonextraction, 31 extraction) who underwent surgical-orthodontic treatment were collected. The changes in maxillary and mandibular dental arch widths were measured from the canines to the second molars. Orthodontic tooth movement was evaluated with an angulation-and-inclination measuring gauge. RESULTS: Statistical analyses showed that intermaxillary arch congruity was attributed mainly to maxillary arch-width changes. The arch-width changes could be interpreted as the result of inclination changes in both posterior dentitions. For the arch-width change, analysis of covariance (ANCOVA) showed a significant extraction effect: the premolar extraction group's ability to accommodate arch-width change was significantly greater than that of the nonextraction group. CONCLUSIONS: The indications for maxillary premolar extraction in Class III presurgical orthodontic treatment might depend in part on the characteristics of the maxillary arch width and posterior teeth inclinations.

Adult↗
PubMed2005

Classification of the skeletal variation in normal occlusion.

The aims of this study were to classify normal occlusion samples into specific skeletal types and to analyze the dentoalveolar compensation in a normal occlusion in order to provide the clinically applicable differential diagnostic criteria for an individual malocclusion patient. Lateral cephalograms of 294 normal occlusion samples, who were selected from 15,836 adults through a community dental health survey, were measured. Using a principal component analysis, two factors representing the anteroposterior and vertical skeletal relationships were extracted from 18 skeletal variables. Cluster analysis was then used to classify the skeletal patterns into nine types. Nine types of polygonal charts with a profilogram were created. Discriminant analysis with a stepwise entry of variables was designed to identify several potential variables for skeletal typing, which could be linked with computerized cephalometric analysis for an individual malocclusion patient. Discriminant analysis assigned 87.8% classification accuracy to the predictive model. It was concluded that because the range of a normal occlusion includes quite diverse anteroposterior and vertical skeletal relationships, classifying the skeletal pattern and establishing an individual dentoalveolar treatment objective might facilitate clinical practice.

Adult↗