The aim of this study was to compare the pain experience among orthodontic patients treated with self-ligating brackets SmartClip® (3M Unitek, Monrovia, California, USA) and conventional brackets Victory series® (3M Unitek, Monrovia, California, USA). We used a controlled clinical trial study design to compare 69 patients treated with self-ligating to 70 patients treated by conventional brackets. The nickel-titanium archwires 0.012-in were engaged after bonding both arches on the first day; and the visual analogue scale (VAS) was used to assess the pain experience of subjects for the first seven treatment days. The pre-treatment dental study models were assessed by the Little’s irregularity index to quantify the groups’ malalignment characteristics. The self-ligating brackets reported lower pain experience than the conventional group on the first five treatment days. However, the sixth day showed 1.75 mm higher visual analogue score than conventional brackets, with almost equal pain level on the seventh day. The group differences throughout the first week were neither clinically nor statistically significant. The pain experiences in both groups decreased steadily from the third treatment day to the end of the first week of treatment. Based on the study findings, the pain experience during initial alignment is not influenced by the brackets’ ligation type. The pain experience tends to decrease steadily from the third treatment day to the end of the first week of treatment irrespective of the bracket type used.
Orthodontic Brackets, Orthodontic Appliances

OBJECTIVE: With an increasing demand for esthetic orthodontic appliances, the interest in polycarbonate brackets has also increased. However, polycarbonate bracket wings are prone to fracture. The purpose of this study was to evaluate the clinical usefulness of a newly-developed polycarbonate bracket by measuring the fracture strength of bracket tie wings. METHODS: Alice (K.M. Daicom, Seoul, Korea) and Spirit MB (Ormco, Glendora, CA, USA) brackets were used as an experimental and control bracket respectively. Each bracket group was divided into halves. One half was untreated and the other half was treated with 2,000 times of thermocycling between 5 degrees C and 55 degrees C. The fracture strength of the wing was measured by a universal testing machine. RESULTS: Alice bracket wings showed significantly higher strength than Spirit MB bracket wings in both untreated and thermocycled bracket cases. CONCLUSION: Alice brackets may be used clinically in terms of the strength of bracket wings.
Orthodontic Appliances ; Seoul

The lingual multibracket appliance was developed to overcome the unesthetic nature of traditional fixed orthodontic labial appliances; however, treatment with this appliance was regarded as very difficult as well as a time-consuming. Recently, these problems have been reduced because of advances in lingual bracket systems, improved indirect bonding technique and the development of more flexible wires. There has been a marked increase in the number of adults desiring orthodontic treatment over recent years and many of these patients tend to seek invisible orthodontic appliances due to esthetic reasons. Although the lingual multibracket treatment is not ideal, this form of treatment is currently the best option for the patients with esthetic concerns. Here, I would like to present a case treated successfully with lingual multibracket appliance.
Adult ; Humans ; Orthodontic Appliances

China ; Humans ; Orthodontic Appliances

It is important to understand the operating mechanism and force system of fixed appliance that most effective for individual tooth movement in various orthodontic appliances. The arch wire system of fixed appliance is devided into 3 types, which is continuous arch, segmented arch and sectional arch. The last two types have longer interbracket distance and simple force operating points, so it is easy to control force system by operator. But the continuous arch has shorter interbracket distance and various bracket geometry, so it is hard to control and anaylze the force system. The purpose of this study was three dimentional force and moment analysis of continuous arch system by finite element method, which is similar situation to three dimentional elastic beam in structural engineering. Several sample form of various bracket geometry and artificial lower crowding typodont made by author were constructed, analyzed and compared each other. The results were as follows: 1. The force magnitude is linear proportional to the degree of displacement or tilting of the bracket. 2. The force magnitude is inversely non-linear proportional to the interbracket distance. 3. In three dimensional typodont model, while the force can be compared with that of the sample form in the area where adjacent bracket geometry is simple, the force is much more than the expected value in the area where adjacent bracket geometry is complex.
Crowding ; Orthodontic Appliances ; Tooth Movement

Humans ; Orthodontic Appliances ; Orthodontics, Corrective

OBJECTIVE: Soft tissue changes due to orthodontic treatment has large individual variation. Therefore continuous evaluation during treatment is required. Patients with fixed orthodontic appliances often wonder if their lip positions will change after the removal of brackets, but only a few studies exist on this topic. The objective of this study was to evaluate the changes of the lips and perioral soft tissue after bracket removal. METHODS: The sample used in this study was 19 males and 33 females. Cephalometric X-rays were taken at 3 stages - T1 (before debonding), T2 (just after debonding), T3 (1.5 months after debonding). RESULTS: The lower lip was retruded immediately after debonding (T2-T1), and 1.5 months after debonding (T3-T2). The mean amounts of retrusion from the vertical reference plane (sG perpendicular line) were about 0.38 mm for the upper lip and 0.88 mm for the lower lip. Immediately after debonding, lip retrusion of females was greater than that of males. During the post-debonding period, lower lip of males was retruded more than that of females. CONCLUSION: Lips are retruded after bracket removal, and there is no gender difference 1.5 months after debonding.
Female ; Humans ; Lip* ; Male ; Orthodontic Appliances

The aim of this investigation was to study the effect of orthodontic force on the flow of gingival crevicular fluid and activities of arylsulfatase and brta-glucuronidase in crevicular fluid. The material consisted of 12 persons between the ages of 13 years and 22 years and all were categorized Class I, 4-4 extraction cases Crevicular fluids were sampled from distal crevis of each canine before treatment (phase 1), after bracketing (phase 2), after application of force (phase 3) and after run out of orthodontic force (phase 4). Crevicular fluid flow did not show any significant changes during the period of treatment. The activities of arylsulfatase increased significantly after setting of orthodontic appliance without application of force, but did not show any significant difference after application of force. The activities of beta-glucuronidase increased significantly after application of orthodontic force and decreased with force deminished. These indicated that beta-glucuronidase was good indicator of bone remodelling resulted from initial orthodontic force.
Gingival Crevicular Fluid* ; Glucuronidase ; Humans ; Orthodontic Appliances

Angulation and inclination of clinical crown is important for diagnosing, treatment planning and developing convenient orthodontic attachments. The aim of the study was to establish normative data with higher reliability on the angulation and inclination of clinical crown of Koreans with normal occlusion. This study employed the dental casts of 307 (male, 187; female, 120) adult normal occlusion samples. The angulation and inclination of clinical crown were measured by set-up model checker. In order to ensure reliability, intra- and inter-rater error were evaluated 3 times. The resultant data obtained had excellent reliability, however, when compared with the previous data as well as with gender difference, clinically significant interpretation was impossible because the whithin-dataset normal variation was high, which was common pattern of angulation and inclination measuring data of previous research. The result of this biometric study seemed to suggest more substantive design of the multivariate, high-dimensional interpretation methodology of these normal variation is required if more compatible orthodontic appliance could be developed.
Adult ; Crowns* ; Female ; Humans ; Orthodontic Appliances

A study of the effects of multibanded orthodontic appliances on the oral lactobacilli was conducted on 41 multibanded group and 41 caries free group. The following conclusions were obtained. 1. In multibanded group, the average count of lactobacilli per milli-liter of saliva showed about 219,300 in male and 254,100 in female. In caries free group, the mean count of lactobacilli per milli-liter of saliva showed about 66,700 in male and 68,500 in female, Therefore, the average of lactobacilli in multibanded group was much higher than that of the caries free group in both sexes. 2. The average of all the types of lactobacilli colonies (Disk-type, Bell-type, Y-type) in multibanded group was much more than that of caries free group. 3. Multibanded orthodontic appliances were found to sufficiently alter oral environment to significantly affect disk-types and total counts in both sexes and bell-type in female, at 1% level of confidence. But changes in bell-type and y-type, in male, were considered to be significant at 5% level of confidence.
Female ; Humans ; Male ; Orthodontic Appliances* ; Saliva