Quad-helix Appliance Research Articles

Effects of appliace size, arch wire diameter, and alloy composition on the in vitro delivery of the quad-helix appliace

The quad-helix appliace is a fixed lingual arch wire appliace that produces slow maxillary expansion for the treatment of maxillary constriction or crossbite in the primary and mixed dentitions. Despite considerable success in the clinical treatment of patients, there is little quantitative information about the force delivery of this appliace. The purpose of this investigation was to characterize the in vitro force delivery of the quad-helix appliance. Appliances of four sizes were fabricated from Elgiloy blue and stainless steel wires with diameters of 0.032, 0.036, and 0.038 inch. The force delivery in grams for 8-mm activation was determined from the force-extension characteristics using an Instron mechanical testing machine. The results show that the force delivery on the quad-helix appliace is affected significantly by changes in the appliance size and arch wire diameter, but is independent of alloy type (stainless steel of Elgiloy blue). The quantitative results from this investigation should provide worthwhile information for clinical appliance selection and treatment of patients with varying arch dimensions.

Maxillary expansion of unilateral cross-bite in preschool children.

The influence of a low force appliance on the maxilla in correction of unilateral cross-bite was studied clinically and radiographically in 29 preschool children following a standardized treatment schedule. Four weeks' expansion was followed by a 4-wk retention and a 12-wk postretention period. Inter- and intraobserver evaluations of the reliability of the measurements on radiographs were performed. In all children but one the cross-bites were corrected after 4 wk of expansion. The mean maxillary expansion was 3.3 mm in the second molar and 1.3 mm in the canine region, but decreased to 1.5 mm and 1.0 mm, respectively, at the end of the postretention period without relapse of the corrected malocclusion. No significant remaining orthopedic effects could be registered on radiographs by this low force appliance used. The modified quad helix appliance was found to be suitable for correction of unilateral cross-bite in the primary dentition and was well tolerated by the children.

上顎骨側方拡大装置 Quad-helix による正中口蓋縫合の拡大に関する病理組織学的研究

The present study was performed to examine clinically and histopathologically the effects of maxillary expansion using the quad-helix appliance. Twenty seven young dogs were divided into nine groups of three dogs each. One group was used as control. A force of 600g was applied for expansion of the maxillary dental arch. Five groups were sacrificed at 1, 2, 3, 4, and 6 weeks after appliance insertion. Three other groups were sacrificed at 3, 4, and 6 weeks after appliance reactivation 2 weeks post-insertion. 1. At first the amount of maxillary arch width increased from 3 to 4 weeks after appliance insertion in the anterior area of the surviving dogs. But 5 weeks after insertion, the arch width of the posterior area was more expanded than that of the anterior area. 2. In comparison with the groups which were activated once, the amount of maxillary arch width was greater in the reactivated groups. 3. The quad-helix appliance caused wedge-shaped expansion of the midpalatal suture, with the anterior area more widely open as shown in the occlusal roentgenogram. 4. The histopathological examination of midpalatal suture was performed after maxillary expansion and tissue blocks were removed from the selected sites : the incisive area, maxillary area and palatine area. 1) The suture was separated but the sutural spaces were filled with newly formed bone, and the suture maintained its shape after maxillary expansion in all experimental groups. 2) In the reactivated groups, the new bone formation proceeded actively and the restoration of sutural area was satisfactory, although the amount of sutural expansion was greater than that of the singly activated groups. 3) In the incisive area, the histopathologic findings of both experimental groups indicated almost the same type of mechanical influences. 4) The maxillary area consisted of midpalatal, interincisive, incisivomaxillary and vomeroincisive sutures. The width of the sutural expansion was greater along the oral surface than along the nasal surface. In the singly activated groups, the expansion of each suture following new bone formation and restoration occurred very smoothly during all periods. But in the reactivated groups, in long range cases, the expansion of the midpalatal suture was greatest. Consequently bone formation in the maxillary area did not take place, in contrast with the singly activated groups. However, in the other sutures of the upper region, the restoration proceeded actively and the function and shape of the palatal vault were maintained by the compensating growth of the other sutures. 5) In the reactivated groups, the sutural expansion of the palatine area was slightly greater than in the singly activated groups.

The effects on the maxillary complex induced by the quad helix appliance: Kazutoshi KamogashiraJ. Jpn. Orthod.42:442–453, 1983

NAL OF ORTHODONTICS is a reflection of current opinion, there is still some controversy over the exact role of orthodontic treatment in mandibular growth. The present article from the University of Oulu in Finland by one of the more respected researchers approaches the condylar growth question by altering the condylefossa relationship. An upward displacement of the glenoid fossa was produced in 40 Long/Evans Turku rats by gluing the interparietal and temporoparietal sutures with methyl-cyanoacrylate at the age of 7 days. The reactions of-the facial structures were studied biometrically from dried skulls. The studies were made from roentgenographic and histologic examination, and from photographs of the temporomandibular joints. The glenoid fossae were found to be superiorly displaced in the experimental animals when measured from the cranial base, the palatal plane, and the occlusal plane. The height of the mandible was unaffected, but its length tended to be greater at 50 and 100 days. The condyles of the experimental animals were located slightly more forward in relation to the fossa at 15 and 25 days. The results support the author's hypothesis that, although the mandible is carried forward passively by the elastic soft tissues, the growth of the condylar cartilage pushes the condylar process downward, thus mainly affecting the vertical jaw relationship and also to some extent the sagittal relationship through anterior or posterior rotation of the mandible. The present study supports the widely held thesis that the condyles are at least partially adaptable to environmental changes, including orthodontic intervention. This supports the voluminous research of Petrovic and co-workers. T. M. Graber

The effects on the maxillary complex induced by the quad helix appliance: Kazutoshi Kamogashira, Shunji Hata, Kazuhiro Ichikawa, Takahisa Hirose, Atsushi Kubota, and Mitsunari Matsumoto.J. Jpn. Orthod. Soc. 42: 442–453, 1983

The effects on the maxillary complex induced by the quad helix appliance: Kazutoshi Kamogashira, Shunji Hata, Kazuhiro Ichikawa, Takahisa Hirose, Atsushi Kubota, and Mitsunari Matsumoto.J. Jpn. Orthod. Soc. 42: 442–453, 1983

The removable quadhelix appliance.

The introduction of a preformed removable quadhelix appliance with curved rotation sheaths for insertion and removal has overcome many of the clinical problems associated with the fixed quadhelix appliance. The design, fitting and activation of the appliance are described. Various applications and modifications are discussed.

Observation of orthopedic force distribution produced by maxillary orthodontic appliances

A three-dimensional anatomic model was duplicated from a human skull, using different birefringent materials to simulate the various craniofacial structures. Individual bones of the midface were fabricated separately and then articulated in their correct sutural relation. One removable and four fixed maxillary appliances were used. The fixed appliances included the Haas, Minne-expander, Hyrax, and quad helix devices. The removable appliance incorporated an expansion screw in a full acrylic palate with appropriate retentive clasps. After the insertion of each appliance, intraoral forces were produced by incremental activation. The model was examined and photographed in the field of a transmission polariscope. Each appliance used produced a different range of load-activation characteristics. This was reflected by the differences in the stresses transmitted through the bones of the craniofacial complex and the effect on the various sutures. Stresses produced by the fixed appliances were concentrated in the anterior region of the palate, progressing posteriorly toward the palatine bone. The Haas, Minne-expander, and Hyrax appliances produced stresses that radiated superiorly along the perpendicular plates of the palatine bone to deeper anatomic structures, such as the lacrimal, nasal, and malar bones, as well as the pterygoid plates of the sphenoid. Similar stress characteristics were seen with the removable appliance. However, increased activation decreased retention of the appliance, thereby lessening the stress. The quad helix appliance proved to be the least effective orthopedic device. Although the effects of palate separation were seen with increased activation, this appliance primarily affected the posterior teeth.

The effects of maxillary quad-helix appliance expansion on cephalometric measurements in growing orthodontic patients

This study was conducted to examine the effects of maxillary quad-helix expansion on frontal and lateral cephalometric measurements in growing orthodontic patients. Twenty subjects, nine girls and eleven boys ( x age = 10 years 3 months), each exhibiting at least a unilateral posterior lingual cross-bite that had been treated with a maxillary quad-helix appliance, were selected for this study. Posteroanterior and lateral cephalometric radiographs were taken at the beginning of treatment (T 1), when the appliance was removed (T prog, x time = 9 months), and at retention (T 2) and subsequently traced. The T 1 and T 2 dental casts were also measured as supplements to the cephalometric measurements. Significant orthodontic changes, as seen on the frontal radiographs from T 1 to T prog, included a mean increase in maxillary intermolar width of 5.88 mm., a mean increase in average frontal molar relation of 2.95 mm., and a mean increase in maxillary intercanine width of 2.74 mm. The orthopedic changes, as evidenced radiographically, included a mean increase in maxillary width of 0.92 mm. and an increase in average maxillomandibular width of 0.89 mm. From the above data, a 6:1 ratio of orthodontic movement to orthopedic movement was determined. No significant change in mandibular intermolar width was observed from the cephalometric data or from the cast measurements. The most stable cases after expansion had normal nasal widths and narrow maxillary widths. No correlation was shown between the age of the patients and the orthopedic expansion recorded or between the amount of orthodontic/orthopedic expansion and facial type. It was concluded that all expansion changes showed little relapse from T prog to T 2 and that moderate orthopedic expansion is possible with the quad-helix, but only slight orthopedic expansion was consistently demonstrated.

The effect of palatal expansion therapy on the periodontal supporting tissues

Sixty-one postorthodontic patients were examined to determine the effect of rapid and slow palatal expansion therapy on the periodontal supporting structures located at the buccal aspects on the maxillary first permanent molars. Twenty-eight patients were treated with a rapid maxillary expansion (RME) technique using a tissue-borne, fixed, split acrylic appliance (Fig. 1), while thirty-three underwent slow palatal expansion with a quad-helix appliance (Fig. 3). The two groups demonstrated mean increases in maxillary first molar width of 4.6 mm. and 4.3 mm., respectively. Twenty-eight patients treated with a similar light-wire edgewise technique but no palatal expansion were used as a control. Four periodontal parameters were examined, including level of marginal alveolar bone, attachment levels (from CEJ), probing depths, and width of keratinized gingiva. All measurements were made by the same examiner and recorded to the nearest 0.5 mm., using a specially machined and calibrated periodontal probe. The results demonstrated that both lateral expansion groups exhibited minimal differences in periodontal condition when compared to the control group. Periodontal status was good in all groups, with average attachment levels being 0.65 mm., 0.36 mm., and 0.51 mm. in the rapid expansion, slow expansion, and control groups, respectively. Although the mean differences were clinically small, individual variation was evident (Fig. 5). Among the few persons who exhibited the more marked periodontal breakdown at the central aspect of the first molars, most were found in the RME group. Except for the type of expansion therapy experienced, none of a number of other orthodontic variables examined demonstrated a statistically significant influence on the periodontal tissues.

The effects of maxillary expansion using a quad-helix appliance during the deciduous and mixed dentitions

Ten subjects, five in the deciduous dentition and five in the mixed dentition (x̄ age = 6 years 9 months), had functional posterior cross-bites successfully corrected with fixed lingual arch wire expansion appliances of the quad-helix design. The appliance, in the context of “early” treatment, produced midpalatal suture separation on each subject as evidenced on occlusal radiographs. While the relative orthopedic and orthodontic changes were not determined, the maxillary intermolar and intercanine transverse measurements showed significant increases in all subjects, with mean values of +5.3 mm. and +4.1 mm., respectively. The active phase of treatment averaged 30 days and 1.1 adjustments for the desired expansion to be achieved. Incorporating a standard 6-week retention period, the total appliance wear time had a mean value of 75 days. Following a 3-month postretention adjustment period, relapse of the intermolar and intercanine transverse dimensions presented mean decreases of −1.5 mm. and −1.9 mm., respectively. The relapse potential was successfully compensated for by overexpansion of 2 to 3 mm. during the active phase of treatment. No significant differences were demonstrated between the deciduous- and mixed-dentition groups during the course of maxillary expansion with the quad-helix appliance.

The quadhelix appliance.

The design, construction and clinical management of the quadhelix appliance are discussed. Clinically, the appliance has a useful role to play in malocclusions where moderate expansion of the upper arch is required; the appliance may be modified to act as a space maintainer or to provide additional minor tooth movements.

Evaluation of diagnostic criteria used for patients treated with activators

Sixty-one postorthodontic patients were examined to determine the effect of rapid and slow palatal expansion therapy on the periodontal supporting structures located at the buccal aspects on the maxillary first permanent molars. Twenty-eight patients were treated with a rapid maxillary expansion (RME) technique using a tissue-borne, fixed, split acrylic appliance (Fig. 1), while thirty-three underwent slow palatal expansion with a quad-helix appliance (Fig. 3). The two groups demonstrated mean increases in maxillary first molar width of 4.6 mm. and 4.3 mm., respectively. Twenty-eight patients treated with a similar light-wire edgewise technique but no palatal expansion were used as a control. Four periodontal parameters were examined, including level of marginal alveolar bone, attachment levels (from CEJ), probing depths, and width of keratinized gingiva. All measurements were made by the same examiner and recorded to the nearest 0.5 mm., using a specially machined and calibrated periodontal probe. The results demonstrated that both lateral expansion groups exhibited minimal differences in periodontal condition when compared to the control group. Periodontal status was good in all groups, with average attachment levels being 0.65 mm., 0.36 mm., and 0.51 mm. in the rapid expansion, slow expansion, and control groups, respectively. Although the mean differences were clinically small, individual variation was evident (Fig. 5). Among the few persons who exhibited the more marked periodontal breakdown at the central aspect of the first molars, most were found in the RME group. Except for the type of expansion therapy experienced, none of a number of other orthodontic variables examined demonstrated a statistically significant influence on the periodontal tissues.

Orthopedic and orthodontic applications of the quad-helix appliance

T here has been an evolution of various types of removable appliances to expand collapsed dental arches.l Most of these have been modifications of the time-honored Coffin loop incorporated in a vulcanite plate which was used to expand the upper arch (Fig. 1, A). Although this appliance was adjusted periodically, the force it produced was continuous because of the nature and configuration of the palatal compound loop. One of the most common forms of an expansion removable appliance is that developed by Martin Schwarz and used extensively throughout Europe.2 It utilizes tissue-borne anchorage, and appurtenances of wire for tooth movement. The expansion force produced by the jackscrew mechanism of this appliance is intermittent as compared to the continuous nature of the Coffin loop described previously. More recently, Haas and Wertz4 have recommended rapid expansion of the midpalatal suture for narrow maxillary arches. This is accomplished with a fixed appliance, usually cemented to the maxillary first premolars and first permanent molars, augmented by a palatal jackscrew and acrylic extensions. Because of the greater magnitude of force produced by these fixed appliances, the net effect is a lateral orthopedic movement of the two halves of the maxilla. Chaconas and Caputo5 found that various fixed expansion appliances produced a different range of load-activation characteristics. This was reflected by the differences in the stresses transmitted through the bones of the craniofacial complex and the effect to the various sutures. A fixed “W” expansion palatal type of appliance was originally used by Rickett@ to treat cleft palate conditions which were accompanied by a collapsed dental arch (Fig. 1, B). This appliance acts continuously over a period of time until the initial activation has dissipated.