• The korean journal of orthodontics
• /
• v.44 no.5
• /
• pp.268-277
• /
• 2014

A Brazilian girl aged 14 years and 9 months presented with a chief complaint of protrusive teeth. She had a convex facial profile, extreme overjet, deep bite, lack of passive lip seal, acute nasolabial angle, and retrognathic mandible. Intraorally, she showed maxillary diastemas, slight mandibular incisor crowding, a small maxillary arch, 13-mm overjet, and 4-mm overbite. After the diagnosis of severe Angle Class II division 1 malocclusion, a mandibular protraction appliance was placed to correct the Class II relationships and multiloop edgewise archwires were used for finishing. Follow-up examinations revealed an improved facial profile, normal overjet and overbite, and good intercuspation. The patient was satisfied with her occlusion, smile, and facial appearance. The excellent results suggest that orthodontic camouflage by using a mandibular protraction appliance in combination with the multiloop edgewise archwire technique is an effective option for correcting Class II malocclusions in patients who refuse orthognathic surgery.

• The korean journal of orthodontics
• /
• v.37 no.5
• /
• pp.341-350
• /
• 2007

The purpose of this study was to evaluate how the friction that occurs during the sliding movement of the archwire through esthetic brackets is differently affected by bracket materials, slot designs, and tip angulations of the archwire. Methods: Eight types of brackets with 0.018 inch slots (composite: Brillant (BR); composite with metal slot: Spirit MB (SP); ceramic: Inspire (IN), Signature (SI), Cristaline V (CR); ceramic with metal slot: Clarity (CL), Luxi II (LU); and metal bracket: Integra (IT)), and placed into groups of 20 brackets in each group, were tested in artificial saliva with 0.018 inch stainless steel wire. The wire tip angulations were given as 0, 4 and 8 degrees. Results: CR group significantly showed the lowest frictional force with all wire tip angulations of 0,4, and 8 degrees. IN significantly showed the highest frictional force (p < 0.001). BR (polyoxymethylene) had significantly less frictional force than SP (polycarbonate) (p < 0.001) and showed no significant difference between metal brackets. Friction was increased as the wire tip angulations were increased, but no notches were observed on any parts of the archwire. Conclusions: According to the results of this study, esthetic brackets are superior or similar to 55 brackets from a frictional point of view.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.22 no.2
• /
• pp.107-116
• /
• 2022

Background: Pain during fixed orthodontic treatment can have a detrimental effect on patient treatment compliance. To overcome this, there is a definite need to establish the best pain-relieving methods suitable for orthodontic patients in terms of efficacy and use. The objective of this study was to compare the effect of chewing gum and pre-emptive tenoxicam on pain after initial archwire placement and to evaluate the pain perceptions of orthodontic patients in the two groups while performing various functions at specific time intervals. Methods: Forty-two patients were selected and randomly divided into two groups: group A (chewing gum) and group B (pre-emptive tenoxicam). Pain perception was documented by patients immediately; at 4 h; at bedtime on the day of archwire placement; the next morning; at 24 h; and at bedtime on the 2nd, 3rd, and 7th day after the initial archwire placement. Pain scores were noted during fitting of the posterior teeth, biting, and chewing using a visual analog scale. The data obtained were subjected to statistical analysis. Results: Group A showed a significant increase in pain until the next morning while fitting the posterior teeth, biting, and chewing [36.2, 52.0, 33.4, respectively]], followed by a gradual decrease by the 7th day. Group B showed a significant increase in pain at bedtime on biting, with a peak value of 47.5. Pain on chewing, fitting posterior teeth, peaked the morning of the next day (100.0, 45.0). The Freidman test showed a statistically significant difference with a p-value of < 0.01. Higher pain scores were observed while chewing and biting compared with that while fitting the posterior teeth in both groups. The overall comparison of pain control between the two groups was not statistically significant [P > 0.05] between the two groups. Conclusions: Chewing gum was not inferior to pre-emptive tenoxicam. Thus, chewing gum is a non-pharmacological alternative to analgesics for orthodontic pain control that eliminates the chance of adverse reactions and can be used in the absence of adult observation.

• The korean journal of orthodontics
• /
• v.42 no.3
• /
• pp.129-137
• /
• 2012

Objective: The purpose of this study was to evaluate the surface roughness (SR) of 2 types of orthodontic archwires made by 4 different manufacturers. Methods: This in vitro experimental study was conducted on 35 specimens of 7 different orthodontic archwires, namely, 1 nickel-titanium (NiTi) archwire each from the manufacturers American Orthodontics, OrthoTechnology, All-Star Orthodontics, and Smart Technology, and 1 stainless steel (SS) archwire each from the manufacturers American Orthodontics, OrthoTechnology, and All-Star Orthodontics. Aft er analyzing the composition of each wire by energy-dispersive X-ray analysis, the SR of each wire was determined by scanning electron microscopy (SEM) and surface profilometry. Data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests (${\alpha}$ < 0.05). Results: The average SR of NiTi wires manufactured by Smart Technology, American Orthodontics, OrthoTechnology, and All-Star Orthodontics were $1,289{\pm}915A^{\circ}$, $1,378{\pm}372A^{\circ}$, $2,444{\pm}369A^{\circ}$, and $5,242{\pm}2,832A^{\circ}$, respectively. The average SR of SS wires manufactured by All-Star Orthodontics, OrthoTechnology, and American Orthodontics were $710{\pm}210A^{\circ}$, $1,831{\pm}1,156A^{\circ}$, and $4,018{\pm}2,214A^{\circ}$, respectively. Similar to the results of profilometry, the SEM images showed more defects and cracks on the SS wire made by American Orthodontics and the NiTi wire made by All-Star Orthodontics than others. Conclusions: The NiTi wire manufactured by All-Star Orthodontics and the SS wire made by American Orthodontics were the roughest wires.

• The korean journal of orthodontics
• /
• v.51 no.5
• /
• pp.346-354
• /
• 2021

Objective: To compare the effectiveness of ibuprofen, acetaminophen, and chewing gum for orthodontic pain relief and to assess if chewing gum can be a non-pharmacological alternative for orthodontic pain relief. Methods: The study enrolled 106 patients of both sexes, aged ≥ 12 years, with body weight > 50 kg, and mild-to-moderate dental crowding in the upper arch. After randomization and allocation concealment, the intervention groups were either administered with ibuprofen (400 mg) or acetaminophen (500 mg) or chewed sugar-free chewing gum immediately after initial archwire placement and every 6 hours for 1 week if the pain persisted. The control group did not receive any pain relief. The pain was assessed on a 100-mm visual analog scale at rest and while biting down at T1 (2 hours), T2 (24 hours), T3 (2 days), T4 (3 days), T5 (7 days), and T6 (21 days). Statistical analyses were performed using the Kruskal-Wallis and post-hoc Mann-Whitney U tests (α = 0.05). Results: The chewing gum group experienced more pain relief than the ibuprofen group at while biting down at T3 (p = 0.04) and at rest at T4 (p < 0.001). The chewing gum group reported more pain relief than the acetaminophen and control groups while biting down at T3 (p = 0.03 and p = 0.0006, respectively) and T4 (both p < 0.001). Conclusions: Chewing gum can be a non-pharmacological alternative for orthodontic pain relief at 2 and 3 days after initial archwire placement.

• The korean journal of orthodontics
• /
• v.28 no.1 s.66
• /
• pp.43-49
• /
• 1998

The aim of this study were to measure and compare the stress level on three type brackets and each other material (stainless steel, ceramic) with tipping and torquing forces by using the finite element analysis and to design biomechanically favorable brackets. For this study, three kinds of brackets were selected(A:Transcend-RMO, B:Signature-Unitek, C:PAW: plain archwire appliance-applied for a patent in Yonsei Udiversity). The slot size of bracket was 0.022inch and the size of archwire was 0.0175x0.025inch and taper shaped archwire was used in PAW. Loading force in tipping was 4.27N and torquing force was 32.858N applied by archwire torsion with 19.7degree and 11.3 degree in C type bracket. The conclusions were that (1) The finite element method proved to be a useful tool in the stress analysis of orthodontic bracket subjected to various forces. (2) With tipping, the stresses were concentrated at the gingival wall of the wire slot where it meets the mesial bracket surface and the incisal wall of the wire slot where it meets the distal bracket surface and with torquing, the stresses were concentrated at the junction of the gingival or incisal wall and base of the slot. (3) The maximum stress value was higher in torquing force than tipping force and therefore it is desirable to design on the basis of torquing force. (4) It was considered that the change in material might be affect on the diminish of stress value in the place of stess concentration. (5) The maximum stress value was highest on PAW bracket when the tipping and torquing force was applied and therefore it would be desirable to use mechanically favorable material on PAW bracket.

• The korean journal of orthodontics
• /
• v.25 no.4
• /
• pp.403-414
• /
• 1995

The purpose of this study was to investigate the histologic changes in mandibular periodontium during overbite closure for openbite treatment by continuous arch wires and anterior vertical elastics. Two female monkey(Macaca nemestrina) with permanent dentition were used. Posterior bite block was fixed to each of their maxillae, which made the animal temporary anterior openbite as well as stabilized the whole maxillary anchorage. In each mandible, all the teeth except the second molars which had been extracted, were prepared for cast crowns. 018 inch Standard brackets were welded on these crowns. After cementation, two types of the $016{\times}022$ inch continuous arch wires, the plain ideal arch to the control animal and the MEAW(multiloop edgewise archwire) to the other experimental one were inserted. Then anterior vertical elastics were applied for two weeks. The overbite depth changes in the monkeys and histologic examinations of the mandibular periodontiums suggested the following conclusions. 1. During two weeks of the experimental period, the overbite increased + 0.3 mm in the control and + 1.3 mm in the experimental one. 2. In both the control and the experimental animal, histologic examinations showed that incisors, canines and first premolars were subject to extrusive force and the rest of posteriors were subject to intrusive one. 3. In periodontiums of the extruded incisors of the experimental one, reorientation of the periodontal fiber structures reflected the direction of force and the alveolar bone surfaces including apical and crestal areas which had been subject to tension, were the front of new bone formation. 4. In periodontiums of the extruded incisors of the experimental one, neither excessive hyalinization nor gross root resorption was observed. 5. Alveolar bone remodeling of anteriors and posteriors was more remarkable in the experimental one than the control.

• The korean journal of orthodontics
• /
• v.26 no.1 s.54
• /
• pp.17-32
• /
• 1996

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 archwire 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.

• The korean journal of orthodontics
• /
• v.42 no.5
• /
• pp.270-278
• /
• 2012

In the correction of dental Class III molar relationship in skeletal Class II patients, uprighting of the mandibular posterior segments without opening the mandible is an important treatment objective. In the case reported herein, a C-tube miniplate fixed to the lower labial symphysis and connected with a nickel-titanium reverse-curved archwire provided effective uprighting of the lower molars, without the need of orthodontic appliances on the mandibular anteriors. Using this approach, an appropriate magnitude of force is exerted on the molars while avoiding any negative effect on the mandibular anteriors.

• The korean journal of orthodontics
• /
• v.31 no.2 s.85
• /
• pp.271-281
• /
• 2001

The Purpose of this study was fourfold - to evaluate the general laws of friction applied to orthodontic conditions, to compare archwire materials under these controlled conditions, to compare ligation method, and to measure the effect of the artificial saliva on friction with these materials Three wire alloys (Cobalt-chromium, Nickel-titanium, Beta-titanium) in two size wires (.016" , .016" ${\times}$.022" ) were examined respect to the bracket (.018" ${\times}$.025" standard), and two ligature material (stainless steel, elastomeric) in dry and wet conditions The results were as follows, 1. The order of frictional force against alloy materials was Co-Cr (lowest), Ni-Ti, and ${\beta}$-Ti(highest) - with the exception of elastomeric ligation under wet conditions. 2. S.S. ligation gave rise to significantly greater friction than elastomeric ligation did. 3. Testing in the presence of saliva, rather than in dry conditions, decreased the frictional force for S.S. ligation with .016" Co-Cr, Ni-Ti, ${\beta}$-Ti. but, increased the frictional force for S.S. ligation with .016" ${\times}$ .022" Co-Cr, Ni-Ti, ${\beta}$-Ti. 4. .016" ${\times}$.022 " wire generated more friction than .016" wire.