Traction Hook Research Articles

Modified Mandibular Lingual Arch for Orthodontic Traction of Impacted Mandibular Canine and Premolar: Case Reports

Impaction of the tooth can cause functional and esthetic problems, so early intervention is critical. This report describes two cases of orthodontic traction of impacted mandibular canine and mandibular premolar teeth using a modified mandibular lingual arch soldered with traction hooks rather than a conventional orthodontic appliance. By planning the position and shape of the traction hooks with consideration for the three-dimensional position and angulation of the impacted teeth, clinicians can apply the intended direction and magnitude of traction force. Furthermore, this appliance can be used for multiple impacted teeth in various locations within the mandibular arch by modifying the position and shape of the traction hooks.

Biomechanical evaluation of maxillary protraction with an orthodontic anchor screw: a three-dimensional finite element analysis

ABSTRACT Purpose The purpose of this study was to biomechanically evaluate maxillary protraction using an orthodontic anchor screw. We conducted three-dimensional finite element analysis to determine the initial displacement and stress distribution during maxillary protraction by comparing a conventional method involving fixation on teeth with maxillary protraction using an orthodontic anchor screw. Materials and methods We used X-ray computed tomography data obtained from Hellman Dental Age IIIA dry human skulls to create a skeletal anchorage model and a dental anchorage model as finite element models. In each model, a load of 6 N was applied in the anteroinferior direction at 0°, 10°, 20°, 30°, and 40° to the occlusal plane by means of a traction hook and the initial displacement and stress distribution were analysed. Results For the anterior nasal spine (ANS) sagittal displacement was greater in the skeletal anchorage model than in the dental anchorage model. In the central incisors and first molars, greater sagittal displacement was observed in the dental anchorage model compared with the skeletal anchorage model. In both models, vertical displacement was 20°, indicating maximum suppression of rotation in the maxilla. The zygomaticomaxillary and zygomaticofrontal sutures demonstrated high stress at 0° and 10° in the dental anchorage model, and at 20°, 30°, and 40° in the skeletal anchorage model. Conclusions These results indicate that tooth and bone–borne maxillary protraction using an orthodontic anchor screw inserted in the palatal region may be of value for the early mixed dentition period in patients with maxillary deficiency.

Three-Dimensional Finite Element Analysis on En-Masse Retraction of the Maxillary Anterior Teeth With Quantitative Combined Loading Control.

This study aims to elucidate the biomechanical effects of combined loading of maxillary anterior and posterior implants using the sliding method on en-masse retraction of the anterior teeth and to quantify the loading ratio (LR) of anterior and posterior implants to achieve controlled retraction of the maxillary anterior teeth. A three-dimensional finite element model of the maxilla-upper dentition appliance was constructed. Implants were placed on the distal (A) and mesial (B) sides of the lateral incisors as well as on the mesial (C) side of the first molar and different amounts of force were loaded between the implants using 2- or 5-mm traction hooks. The labiolingual movement of the anterior teeth was recorded and the relationship between the LR of the implants and the movement of the central incisors was evaluated. With 2-mm traction hooks, the central incisors exhibited a translation tendency during retraction at lower A/C and B/C LR and labial or lingual crown inclination at higher values. With 5-mm traction hooks, the central incisors, lateral incisors, and canine teeth exhibited a labial crown inclination. The results of this study suggest that 2-mm traction hooks can cause labial crown inclination, translation tendency during retraction, or lingual crown inclination of the central incisors due to alterations in the LR of the anterior and posterior implants. The central incisors only exhibited labial crown inclination during combined loading of the anterior and posterior implants when 5-mm traction hooks were used.

Rigid External Distraction with Intranasal Bone-borne Traction Hooks for Midfacial Hypoplasia

Rigid external distraction is currently performed to correct cases of severe maxillary hypoplasia. As an improvement of this technique, we propose the use of an intranasal bone-borne traction hook. This study is a retrospective chart review of the intranasal bone-borne traction hooks used in the treatment of severe maxillary hypoplasia. There were 110 patients treated with the hooks from 2005 to 2017. The maximum traction force was 7.75 kg, and there were few complications encountered during distraction. There were 76 patients who had the hooks removed under local anaesthesia. A cephalometric analysis was conducted in 56 patients. The average advancement of A-point was 9.9 ± 4.2 mm, 8.4 ± 2.5 mm, 11.0 ± 3.7 mm, 17.9 ± 4.4 mm for the trans-sutural distraction osteogenesis (DO), maxillary anterior segment DO, Le Fort I osteotomy DO and Le Fort III/II osteotomy DO, respectively. The average changes of sella-nasion-point A (SNA) were 8.89 ± 4.30 degrees, 8.21 ± 3.17 degrees, 10.49 ± 3.26 degrees, and 15.10 ± 4.00 degrees, respectively. The A point-nasion-B point (ANB) also showed increases in all procedures with P < 0.001. In conclusion, this technique sufficiently advances the midface and ensures the scars are concealed in the nasal base. The traction hook can bear a large traction force, causes minimal complications and is easily removed.

Analysis of causes of a locomotive draw hook brittle fracture

The traction force of locomotives is constantly increasing due to the pulling of heavier trains, while the material of the draw hooks remained the same as 50 years ago. The use of the current UIC standards and the relevant national standards defining the methodology for testing the mechanical properties of the hooks is very problematic. Despite the fact that all material properties of the draw hooks, tested according to UIC 825 and other related standards (In Czech and Slovak republic TNŽ 28 2612 standard) fully comply with the minimum values set by the standards, in operation the unexpected failure occurs frequently. This article deals with causes of brittle fractures of locomotive draw hooks operated by Slovak Railways. An exemplary study uses a traction hook of a locomotive that broke when a freight train accelerated after the stop at signal between the two stations in the winter period at ambient air temperature of -2 °C. The performed analysis showed that the brittle fracture of the draw hook was caused by usage of the low-toughness steel with the coarsened microstructure. All experimentally measured material properties of a broken hook met the limits specified in UIC 825 and TNŽ 28 2612 standards as the material testing at temperatures below +20 °C is not required in those standards. This study shows that the only technical solution to the long-term persistent problem of brittle fractures of locomotive draw hooks is to redefine their acceptance conditions and change the prescription for testing of the impact strength of the steels, from which the draw hooks are made.

Midface Distraction Osteogenesis Using a Modified External Device With Elastic Distraction for Crouzon Syndrome.

Midface distraction osteogenesis has been popularized for the correction of midface hypoplasia associated with exophthalmos and obstructive sleep apnea in patients with Crouzon syndrome. The purpose of this study was to present the method of utilizing the modified external device with elastic distraction for the midface advancement in Crouzon syndrome, and the clinical outcomes and skeletal changes were analyzed. Five consecutive patients with Crouzon syndrome underwent Le Fort III osteotomy with midface advancement using a modified external device with elastic distraction. The distraction system consists of a rigid external distractor, nickel-titanium shape memory alloy spring, and bone-borne traction hooks. The midface advancement was initiated with the bony anchorage around the nasomaxillary buttress at the level between occlusal plane and infraorbital margin. The device was activated at a rate of 1 to 1.5 mm per day by the length of spring. The skeletal changes were analyzed by cephalometric and computed tomographic measurement. All the patients achieved improvements in midface appearance, obstructive sleep apnea, exophthalmos, and occlusion. No complications occurred during this procedure. After the distraction, 1 patient developed an open bite that was corrected by a definitive orthognathic surgery. Cephalometric and computed tomographic measurement analysis showed a differential advancement of midface with more at the occlusal level than the orbital level. In addition, midface suture and bone remodeling was also observed in growing patient. Our modified external device with elastic distraction offers an alternative method to achieve midface advancement in patients with Crouzon syndrome.

Reduction of superior-lateral intact mandibular condyle dislocation with bone traction hook

Lateral and superior-lateral dislocations of the intact condyle are a rare complication, following traumatic insult to the mandible. We report an unusual case of a 54-year-old male patient who experienced both types of dislocations of the intact condyles with symphysis fracture following a road-traffic accident. Under general anesthesia, conventional manipulation was unsuccessful in relocating the condyles into the glenoid fossa. After applying a percutaneous traction force, using a bone traction hook placed at the sigmoid notch, the displaced intact mandibular condyles were repositioned, and the symphyseal fracture was finally reduced and fixed. The mouth opening was within normal limits, and favorable occlusion was confirmed one month postoperatively. To our knowledge, this is the first case of dislocation of both intact condyles--associated with symphysis fracture--being reduced with bone traction hook.

Research on characteristics and treatment duration and method of patients with tooth impaction who visited Gachon University Gil Hospital Orthodontic Department (year 2005-2008)

Purpose: An impacted tooth is defined as a tooth that shows delayed eruption and is expected to erupt incompletely by clinical and radiograph examination despite it reaching its expected time of eruption. The aims of this study were to investigate the clinical and radiological characteristics and treatment duration and method of impacted teeth in Korean patients. Materials and Methods: For this study we used clinical records, study models, panoramic radiographs and intraoral photographs of patients who attended Gachon University Gil Hospital Orthodontic Department between 2005 and 2008. There were 164 patients with a total number of 202 impacted teeth. Results: Male patients shows a little more prevalence than female patients (1.13:1). The under 12 age group had the highest prevalence of tooth impaction, and the over 19 age group showed the least prevalence of tooth impaction. The ratio of tooth impaction between the left to right ratio was 1.73:1 and maxilla and mandible was 1.84:1. The impacted teeth were most commonly positioned buccally (76 cases, 41.5%). Full nap closure technique (108 cases, 81.2%)was most frequently used for attachment of surgical traction hooks. Maxillary canine impaction was most commonly encountered both in male and female patients. The mean treatment period was 12.2 months and the success rate of treatment was 90.3%. The canine tooth shows the longest treatment time and highest failure rate. The ankylosis was the major cause of failure. Conclusion: Impacted teeth most commonly show in left side maxilla in the under 12 age group. And it is most commonly positioned buccally. The mean treatment period was 12.2 months, and the success rate of treatment was 90.3%.

Application of Orthodontic Mini-Implants and Ligation for Absolute Skeletal Anchorage to the Intraoral Labiolingual Appliance

Patients with cleft and several craniofacial syndromes usually show skeletal class III malocclusion with midface hypoplasia. Although the Rigid External Distraction (RED) System (KLS Martin, LP, Jacksonville, FL) has been used widely, bowing of the external traction hooks (ETHs) and tooth-borne anchorage for the intraoral labiolingual appliance (ILA) can result in inappropriate change of force application level and vector control, eventually improper rotation of the osteotomized bony segment and unwanted dentoalveolar effect. Instead of the ETH and ILA, direct fixation of the skeletal plate on the maxilla can be another option. However, it also has some disadvantages including inflammation, fixation failure, and the need for a second surgery to remove the plates. These phenomena could be minimized by the addition of rigidity to the ETHs and fortification of absolute skeletal anchorage to the ILA. Therefore, the purpose of this article was to introduce application orthodontic mini-implants on the buccal attached gingiva and palate areas and ligation for absolute skeletal anchorage to the ILA in midface distraction osteogenesis cases treated with the RED System. In cases that need a large amount of advancement and bodily translation or clockwise rotation of the midface and that have oligodontia or anchorage problem for the ILA, application of the orthodontic mini-implants and ligation for absolute skeletal anchorage to the ILA can be a highly effective fixation approach to obtain more accurate vector control.

Removable splint with locking attachments for maxillary distraction osteogenesis with the RED system

The external traction hooks of the intraoral splint used to control traction forces applied to the maxilla with the rigid external distraction system represent a major barrier to surgical procedures. The purpose of this article is to introduce a removable intraoral splint with locking attachments that can be placed post-surgically immediately before distraction, facilitating surgery and consequently reducing the operative time. Fifteen cleft lip and palate patients underwent maxillary distraction osteogenesis using a rigid external distraction device in combination with the proposed removable splint that was fixed onto the maxillary teeth to provide anchorage. Initial records showed severe maxillary hypoplasia and negative overjet. The removable splint was fabricated using 1.5-mm diameter stainless-steel rigid orthodontic wires soldered to the locking attachments (Y&B Products LP, Chiang Mai, Thailand), making possible its placement post-surgically. Stable splint fixation was achieved prior to the distraction procedure and the desired treatment goals were reached. No complications inserting or removing the splint post-surgically, including pain or discomfort, were observed. The use of the removable splint with locking attachments has proved to be a highly effective fixation approach to manage the severely hypoplastic maxilla, eliminating lip constraints resulting from scarring, and allowing for easier, more deliberate and careful dissection.

New Fixation Method for Maxillary Distraction Osteogenesis Using Locking Attachments

The external traction hooks of the intraoral splint used in the rigid external distraction (RED) system for maxillary distraction osteogenesis interfere with the surgical procedures. The purpose of this study is to introduce an innovative splint fixation method for maxillary distraction osteogenesis with Locking Attachments and evaluate their advantages, such as reduction of operating time compared with the traditional intraoral splint method. Retrospective comparison of operative times of maxillary Le Fort I osteotomy procedures was carried out with the traditional protocol using the intraoral splint cemented to the maxillary dentition (n = 14), and a removable intraoral splint that is inserted postsurgically (n = 14). Operative procedure times were compared and analyzed statistically using the data extracted from the surgical records. There were no complications inserting the removable splint postsurgically, including pain, discomfort, or time-consuming procedure. Stable and secure splint fixation was obtained before the distraction procedure and the desired treatment goals were obtained in all patients. The total operative procedure times were significantly reduced in the Locking Attachments group by 24% to 41% (approximately 65 minutes) compared with earlier operations involving the conventional splints (P < .05). Maxillary distraction osteogenesis with the Locking Attachments is a highly effective fixation approach to manage severe hypoplastic maxilla, eliminating lip constraints resulting from scarring and allowing for easier, more deliberate and careful dissection. The use of the Locking Attachments is reliable in craniofacial surgery and has proved to be advantageous in the reduction of the operating time and surgical risks.

Sutural Distraction Osteogenesis (SDO) Versus Osteotomy Distraction Osteogenesis (ODO) for Midfacial Advancement: A New Technique and Primary Clinical Report

A new technique of osteotomy distraction osteogenesis (ODO) and sutural distraction osteogenesis (SDO) by the use of bone-borne traction hooks is presented. The technique of osteotomy plus distraction osteogenesis is suitable for adult patients. The technique of sutural distraction osteogenesis is suitable for young patients, ages 6 through 12 years. The distraction system consists of a face-bow, orthodontic elastics, and bone-borne traction hooks. The bone-borne traction hooks are made of titanium, with two traction hooks running laterally or downwardly. When a Le Fort III osteotomy is needed, bone-borne traction hooks are inserted through the nostrils into a bone hole drilled at the lateral-inferior pyriform aperture. When no osteotomy is needed, only the bone-borne traction hooks are placed. Heavy elastics were used in the technique of osteotomy distraction osteogenesis for Le Fort III osteotomy adult patients, whereas light forces and thus light elastics were used for younger patients. Three adult patients and four children were treated by osteotomy distraction and sutural distraction, respectively. All seven patients with midfacial hypoplasia established a harmonious facial profile and normal occlusal relationships. Radiographic examination showed balanced advancement of the midfacial skeleton. It is suggested that the treatment of midfacial hypoplasia in children by the technique of sutural distraction osteogenesis is to be preferred because of its simplicity and relative noninvasiveness. Thus, the authors suggest that midfacial hypoplasia should be treated at a younger age by this technique, potentially eliminating the need for a Le Fort III osteotomy at an older age.

Simulation of Freight Trains Equipped with Partially Filled Tank Containers and Related Resonance Phenomenon

To study the fluid motion-vehicle dynamics interaction, a model of four, liquid filled two-axle container freight wagons was set up. The railway vehicle has been modelled as a multi-body system (MBS). To include fluid sloshing, an equivalent mechanical model has been developed and incorporated. The influence of several factors has been studied in computer simulations, such as track defects, curve negotiation, train velocity, wheel wear, liquid and solid wagonload, and container baffles. SIMPACK has been used for MBS analysis, and ANSYS for liquid sloshing modelling and equivalent mechanical systems validation. Acceleration and braking manoeuvres of the freight train set the liquid cargo into motion. This longitudinal sloshing motion of the fluid cargo inside the tanks initiated a swinging motion of some components of the coupling gear. The coupling gear consists of UIC standard traction hooks and coupling screws that are located between buffers. One of the coupling screws is placed in the traction hook of the opposite wagon thus joining the two wagons, whereas the unused coupling screw rests on a hanger. Simulation results showed that, for certain combinations of type of liquid, filling level and container dimensions, the liquid cargo could provoke an undesirable, although not hazardous, release of the unused coupling screw from its hanger. The coupling screw's release was especially obtained when a period of acceleration was followed by an abrupt braking manoeuvre at 1 m/s2. It was shown that a resonance effect between the liquid's oscillation and the coupling screw's rotary motion could be the reason for the coupling screw's undesired release. Possible solutions to avoid the phenomenon are given.

Cricoid ring integrity: Implications for cricothyrotomy

Study objectives: The rapid 4-step technique for cricothyrotomy was originally described as making use of a single traction hook on the cricoid ring. However, it is possible that such hook placement could lead to damage of the cricoid ring. As an alternative, a double-hook device was developed to augment the rapid 4-step technique by dispersing forces applied to the cricoid ring. The objectives of this study were to compare the requisite forces for intubation and the structural tolerances of the cricoid ring between the single- and double-hook techniques. Methods: We randomized 56 human cadaver specimens to undergo either cricothyrotomy with intubation followed by cricoid ring breakage or cricoid ring breakage alone. We randomized those cadaver specimens undergoing cricothyrotomy with intubation with respect to the initial hook technique used and then crossed over to the alternate technique for repeat intubation and subsequent cricoid ring breakage. We performed all cricothyrotomies in a similar manner with a consistent technique. We measured the intubation and breakage forces for the single- and double-hook techniques and calculated 95% confidence intervals (CIs). Results: The mean force to intubate with the single-hook technique was 18 N (95% CI 14 to 22 N), and the mean force to intubate with the double-hook technique was 23 N (95% CI 17 to 29 N). There was a significant difference between the mean forces required to break the cricoid ring with the single-hook technique (54 N; 95% CI 47 to 62 N) versus with the double-hook technique (101 N; 95% CI 89 to 113 N; difference in means 47 [95% CI 34 to 60 N]). Conclusion: When applying the rapid 4-step technique for cricothyrotomy, the force required to intubate with either the single- or double-hook technique is small. The cricoid ring, however, tolerates significantly more force without breakage when the double-hook technique is used. [Ann Emerg Med. 2003;41:331-337.]

Evaluation of antimicrobial properties of orthodontic composite resins combined with benzalkonium chloride

An antimicrobial agent, benzalkonium chloride (BAC), was added to a chemically cured composite resin, and the antimicrobial benefits and physical properties of the modified composite were evaluated. BAC was added to Reliance Phase II composite to create modified composites with BAC concentrations ranging from 0.25 to 2.50 wt%. Specimen disks of the modified composite were incubated with Streptococcus mutans for 48 hours, and an agar disk diffusion assay was used to measure zones of bacterial inhibition. Larger disks were suspended in brain-heart infusion medium containing 2 × 104 colony-forming units/mL Streptococcus sobrinus (10 mL, 2 wt% sucrose, 24 hours) to measure bacterial adherence to the adhesive; adherent cells were removed from the surface with 1 N NaOH, and the optical density of the cells was measured at 550 nanometers. Traction hooks were bonded to bovine teeth with the modified composite, and tensile bond strength was evaluated with a universal testing machine. Diametral tensile stress was also measured. The modified composite samples showed that antimicrobial activity increased with higher BAC content; no antimicrobial activity was measured for the original compound in either the disk diffusion or the bacterial adherence test. There were no significant differences (P <.05) in either tensile bond strength or diametral tensile stress among the modified composite groups and the original product. The incorporation of BAC in composite material added antimicrobial properties to the original compound without altering its mechanical properties. (Am J Orthod Dentofacial Orthop 2002;122:288-94)

A method for reduction of zygomaticomaxillary complex fractures

Many techniques have been developed for mobilization of the displaced zygomaticomaxillary complex fracture. These include the temporal fossa approach first described by Gillies et al, 1 Gillies HD Kilner TP Stone D Fractures of the malar-zygomatic compound, with a description of a new X-ray position. Br J Surg. 1927; 14: 651 Crossref Scopus (142) Google Scholar an upper buccal sulcus approach, 2 Balasubramanian S Intra-oral approach for reduction of malar fractures. B J Oral Surg. 1967; 4: 189 Abstract Full Text PDF PubMed Scopus (9) Google Scholar a lateral coronoid approach useful for medially displaced fractures, 3 Quinn JH Lateral coronoid approach for intra-oral reduction of fractures of the zygomatic arch. J Oral Surg. 1977; 35: 321 PubMed Google Scholar and multiple percutaneous approaches using hooks, 4 Crowe WW Treatment of depressed fracture of the zygomatic bone. J Oral Surg. 1952; 10: 3 PubMed Google Scholar , 5 Poswillo D Reduction of the fractured malar by a traction hook. Br J Oral Surg. 1976; 14: 76 Abstract Full Text PDF PubMed Scopus (20) Google Scholar Carroll-Girard screws, 6 Kreutziger KL Zygomatic fractures: Reduction with the T-bar screw. South Med J. 1992; 85: 1193 Crossref PubMed Scopus (15) Google Scholar and pins. 7 Manson P Discussion: Transcutaneous reduction and external fixation for the treatment of noncomminuted zygoma fractures. J Oral Maxillofac Surg. 1998; 56: 1387 Abstract Full Text PDF Google Scholar

Experience with various procedures in the treatment of orbital floor fractures

Experience gained in the treatment of 75 patients with orbital floor injuries is presented. These injuries occurred independently or in association with mid-face fractures. In fractures of the zygomatic bone and the zygomatic part of the orbit repositioning of the zygomatic bone by a traction hook is the simplest method. In recent multiple fractures of the mid-face it is most suitable to use a lamina from the anterior or medial wall of the maxillary sinus for bridging the orbital floor defect. Osteoplasty of the orbital floor using an iliac bone graft is the method of choice in the treatment of neglected blow-out fractures fo the orbital floor. In cases with recent blow-out fractures of the orbital floor the defect can be bridged by bone taken from the hip or a lamina from the anterior wall of the maxillary sinus. It is not necessary to perform intranasal antrostomy of gauze packing of the sinus.

Traction—A surgical/orthodontic procedure

Maxillary crowding may cause failure of eruption of the canine. The teeth so displaced are directed buccally or palatally. In both cases, surgical intervention is indicated after space has been made in the arch. Palatally displaced canines are treated by surgical excision of palatal mucosa to promote eruption. Wide excision is indicated to prevent the healing process from covering the exposed tooth crown. Because of the anatomy of the buccal mucosa, however, surgical excision of the crowns of buccally displaced canine frequently results in periodontal problems. An alternative technique is therefore presented; this involves the surgical exposure of the crowns of buccally displaced teeth to allow the attachment of a wire traction hook. The crown is then recovered. The traction hook provides a point of attachment, so that orthodontic forces may be applied to the unerupted tooth to guide its eruption. The preservation of the mucosal flap ensures a normal epithelial attachment develops on the buccal surface of the tooth, and the normal gingival anatomy of the buccal mucosa is maintained. The procedure may also be used in cases where upper incisors have been prevented from erupting because of the presence of supernumerary teeth. Even after surgical removal of the supernumerary teeth, the permanent incisors often fail to erupt. In such cases, the placement of traction hooks will enable the orthodontist to bring the unerupted teeth into their correct positions in the arch.

Reduction of the fractured malar by a traction hook

A technique is described for the simple, speedy and effective reduction of the large majorityof fractures of the malar complex by direct extra-oral application of a specially designed traction hook.

The traction hook on the modified arrowhead clasp.

The traction hook on the modified arrowhead clasp.