Protraction Headgear Research Articles

Growth Modification Treatment in Class III Malocclusions - An Orthodontic Case Report

A number of treatment options for Class III malocclusions have been reported. Early intervention incorporating growth modification allows the clinician to attempt mandibular growth restraint and promote the forward growth of the maxilla. At the optimal age for growth modification, rapid maxillary expansion (RME) and protraction headgear can be used to produce these beneficial changes. The following case report describes the management of an 8.5-year-old patient who underwent treatment using RME, protraction headgear and fixed appliances.

Dual Segmental Distraction Osteogenesis of the Midface in a Patient with Apert Syndrome

To present orthodontic treatment combined with dual segmental distraction osteogenesis in a patient with Apert syndrome. A 15-year-old boy exhibited severe midfacial hypoplasia with retruded and hypoplastic maxilla and anterior open bite. The patient was treated with a rigid external distraction II system for distraction osteogenesis, a preadjusted edgewise appliance, and a modified maxillary protraction headgear. The concave profile with midfacial hypoplasia was improved. A tight occlusal relationship between maxillary and mandibular teeth was achieved. Postoperative treatment results have been stable for 1 year.

BOS MOrth Cases Prize 2004

This paper describes the clinical orthodontic treatment of 2 cases that were successfully entered for the 2004 American Orthodontics MOrth Cases Prize. The first case is that of a patient presenting with a Class III malocclusion treated with rapid maxillary expansion and protraction headgear followed by fixed appliance therapy. The second case demonstrates the use of fixed appliances to correct a moderate Class II division I malocclusion.

Rigid External Distraction Osteogenesis for a Patient With Maxillary Hypoplasia and Oligodontia

Abstract Objective: In this report, the orthodontic treatment combined with rigid external distraction osteogenesis in a 5.5-year-old girl with midfacial hypoplasia and oligodontia is described. Patient: The child presented with a reduced maxilla, protruding lower lip, skeletal Class III jaw relationship with a low mandibular plane angle, a short and flattened nose, anterior crossbite, and aplasia of 16 permanent teeth. The patient was treated with rigid external maxillary distraction osteogenesis, maxillary protraction headgear, and Class III elastics. Following treatment, the maxilla was displaced in a forward direction with new bone formation at the tuberosities and the mandible rotated backward in relation to the anterior cranial base. The anterior crossbite was corrected, and the skeletal jaw relationship changed from a Class III to a Class I skeletal pattern. The soft tissue facial profile showed that the nasal projection had been increased, the nasolabial angle increased, and the lower lip protrusi...

The early management of Class III malocclusions using protraction headgear.

Class III malocclusions affect approximately 3% of Caucasians. Treatment options include; growth modification, dental camouflage and, once growth has ceased, orthognathic surgery. Originally, Class III malocclusions were thought to arise primarily from an overdevelopment of the mandible, but it is now known that maxillary retrusion contributes in up to 60% of cases. Maxillary retrusion is best treated with a combination of protraction headgear and rapid maxillary expansion, preferably before the age of 9 years. This article provides an overview of the management of skeletal Class III cases using protraction headgear with particular guidance for the general dental practitioner on when and how to treat.

Treatment of a severe Class III skeletal discrepancy at an appropriate age

Abstract The 13-year-old female patient presented for correction of a severe Class III malocclusion with a Class III skeletal pattern. This was considered an appropriate age for treatment as earlier treatment may have been subject to relapse because significant facial growth may have occurred after treatment, and because treatment at a later age may have required orthognathic surgery. Initially, maxillary expansion was provided to widen the maxilla and to free the circummaxillary sutures. Maxillary protraction headgear was worn to perform sagittal skeletal improvement. Fixed orthodontic appliances were placed to align the dentition and Class III elastics were used to improve intercuspation and stability. Patient cooperation was crucial for success. The skeletal changes provided rewards that included significantly improved facial and dental appearance, while avoiding orthognathic surgery.

The effects of a modified protraction headgear on maxilla

Protraction headgears are commonly used in the treatment of Class III malocclusion characterized by maxillary retrognathism. The upward and forward rotation of the maxilla during protraction is a major unwanted side effect. The aim of this study was to eliminate the upward and forward rotation of maxilla while protracting. Seventeen patients with Class III malocclusion as a result of maxillary retrognathism were treated for 3 months; their average age was 12.81 years. A full coverage acrylic cap splint-type rapid maxillary expansion appliance was cemented and activated twice a day for 5 days. After sutural separation, a maxillary modified protraction headgear was worn and 750 g of force was applied. Wilcoxon signed rank test was carried out to evaluate 42 parameters measured on cephalometric radiographs. The maxilla was displaced anteriorly by downward and backward rotation. The mandible was displaced downward and backward due to anterior elongation of the maxilla. Extrusion and lingual tipping of the upper incisors and intrusion of upper molars and downward and backward rotation of functional occlusal plane were observed. The aim of our study was achieved, which was to avoid upward and forward rotation while protracting the maxilla. In conclusion, maxillary modified protraction headgear (MMPH) can be used effectively in Class III patients with retrognathic maxilla and anterior open bite tendency. (Am J Orthod Dentofacial Orthop 2000;117:27-38)

Design and fabrication of a modified protraction headgear for Class III long face patients

Treatment of children with long face and with Class III malocclusions is difficult because most of the available appliances treat one of the two problems at the cost of aggravating the other one. In this article, we present the steps of design and fabrication of a modified protraction headgear that can be useful for such a patient. A patient treated with this approach is presented. (Am J Orthod Dentofacial Orthop 1999;115:553-8)

A study of holographic interferometry on the initial reaction of maxillofacial complex during protraction

Most extraoral appliances used for protracting small or retropositioned maxilla do not allow for variations in the point of force application or in its direction. This variation may be necessary to control vertical, anteroposterior, as well as transverse effects. The purpose of this study was to investigate the initial reaction of the maxillofacial complex according to force magnitude, force direction, and point of force application. For this purpose, an antenna-type modified protraction headgear was tested with double exposure holographic interferometry on a dry human skull with well-aligned upper teeth. Fringe patterns of each protraction condition were compared and analyzed. In most cases, upward rotation of the anterior portion of the maxilla changed to translation, or to downward rotation, as force direction was changed from parallel to the occlusal plane to 20° downward to the occlusal plane. Furthermore, a 500 gm force applied 15 mm above and directed 20° below the occlusal plane produced a translation of the maxillary complex, indicated by a typical circular fringe pattern on the holographic plate, which represents the center of resistance of the maxilla. In most cases, with all force variables tested, a protraction of the maxilla with palatal expansion was more effective in producing translation of the maxilla than was protraction without palatal expansion. By varying force magnitude, force direction and point of force application with maxillary protraction, the amount of maxillary rotation and translation might be controlled. (Am J Orthod Dentofac Orthop 1997;111:623-32.)

Masticatory muscle pain before, during, and after treatment with orthopedic protraction headgear: a pilot study.

Protraction headgear has been used in conjunction with a palatal expansion appliance to correct Class III malocclusion with maxillary deficiency and/or mandibular prognathism. In general, 800 gm of orthopedic force is used to protract the maxilla, and 75% of this force is transmitted to the temporomandibular joint (TMJ) area via the mandible. The effect of this heavy intermittent force on the TMJ has not been reported in the literature. The objectives of this study were to determine the level of masticatory muscle pain and EMG activity in patients treated with maxillary protraction headgear. Ten patients with skeletal Class III malocclusion whose treatment plan called for maxillary protraction headgear treatment participated in this study. Nocturnal masticatory muscle activity was determined using a portable electromyographic (EMG) recording device. Subjects wore the EMG device 14 nights before treatment, 14 nights during treatment, and 14 nights 1 month after active treatment. Masticatory muscle pain level was determined by muscle palpation, scored on a scale of 0 to 3 each period, according to the method of Gross and Gale. The examiner followed a sequence outlined by Burch to examine the masticatory muscles. Results showed no significant differences for masticatory muscle activities before, during, and after treatment. Only a few patients experienced level 1 masticatory pain during treatment. None of the patients experienced masticatory muscle pain 1 month after treatment. These results demonstrate no significant increase in masticatory muscle activity or muscle pain associated with orthopedic treatment using maxillary protraction headgear.

Soft tissue and dentoskeletal profile changes associated with maxillary expansion and protraction headgear treatment

One of the goals of early treatment of Class III malocclusion with maxillary expansion and protraction headgear is to significantly improve the dentofacial profile. The objectives of the present study were to determine (1) the interrelationships of the soft tissue and dentoskeletal profiles after maxillary expansion and protraction headgear treatment and (2) which cephalometric variables could contribute to an accurate prediction of the protraction effect on the soft tissue profile. Lateral cephalometric radiographs of 20 consecutively treated Class III patients (10 males, 10 females) by protraction headgear were included in this study. Their ages at the start of protraction headgear treatment ranged from 6 to 11 years, with an average of 8.1 ± 2.1 years. None of the patients had previous orthodontic treatment. For each patient, the first lateral cephalogram was taken 6 months before the initiation of headgear treatment (T o), and the second radiograph at the start of treatment (T 1). Therefore (T 1 − T o) represented 6 months of growth with no treatment. A third radiograph was taken 6 months after start of treatment (T 2). In this way, (T 2 − T 1) − (T 1 − T o) represented the effect the result of appliance therapy alone and each subject served as his/her own control. A computerized cephalometric analysis was used including variables assessing sagittal and vertical relationships of skeletal and soft tissue profiles, incisal relationships, soft tissue thickness, and lip structure. Data were analyzed by means of paired t tests, Pearson's product-moment coefficient correlation, and multiple regression analyses. The results showed significant improvements in dentofacial profile after 6 months of maxillary protraction. The skeletal and soft tissue facial profiles were straightened and the posture of the lips was improved. The normal incisal relationship (overjet) that was achieved had a significant impact on the soft tissues overlying both upper and lower incisors resulting in better lip competence and posture. Significant correlations were found between changes in the sagittal relationships of skeletal and soft tissue profiles in both the maxilla and the mandible ( p < 0.05). The forward movement of the maxilla was accompanied by a corresponding forward movement of the soft tissue profile at 50% to 79% of the hard tissue. In the mandible, the downward and backward movements of the soft tissues were equivalent to 71% to 81% of the corresponding hard tissues. The lack of high r square values in the multiple regression analyses reflected a low prediction value for the maxillary variables, but moderately high prediction value for the mandibular variables that could be used in preorthopedic treatment planning. This study showed that significant dentoskeletal changes and improvements in dentofacial profile resulted from 6 months of treatment with maxillary expansion and protraction. (A M J O RTHOD D ENTOFAC O RTHOP 1996;109:38-49.)

Treatment response to maxillary expansion and protraction

A prospective clinical trial was conducted to determine the skeletal and dentalcontributions to the correction of overjet and overbite in Class III patients. Thirty patients (12 males and 18 females with a mean age of 8.4±1.7 years) were treated consecutively with protraction headgear and fixed maxillary expansion appliances. For each patient, a lateral cephalogram was taken 6 months before treatment (T o ); immediately before treatment(T 1 ; and 6 months after treatment (T 2 ). The time period (T 1 –T 0 ) represented changes due to 6 months of growth without treatment; (T 2 –T 1 ) represented 6 months of growth and treatment. Each patient served as his/her own control. Cephalometric analysis described by Bjork (1947) and Pancherz (1982a, b) was used. Sagittal and vertical measurements were made along the occlusal plane (OLs) and the occlusal plane perpendicular (OLp), and superimposed on the mid-sagittal cranial structure. The results revealed the following: with 6 months of treatment, all subjects were treated to Class I or overcorrected to Class I or Class II dental arch relationships. Overjet and sagittal molar relationships improved by an average of 6.2 and 4.5 mm, respectively. This was a result of 1.8 mm of forward maxillary growth, a 2.5-mm of backward movement of the mandible, a 1.7-mm of labial movement of maxillary incisors, a 0.2-mm of lingual movement of mandibular incisors, and a 0.2-mm of greater mesial movement of maxillary than mandibular molars. The mean overbite reduction was 2.6 mm. Maxillary and mandibular molars were erupted occlusally by 0.9 and 1.4-mm, respectively. The mandibular plane angle was increased by 1.5 degrees and the lower facial height by 2.9 mm. Individual variations in response to maxillary protraction was large for most of the parameters tested. Significant differences in treatment changes between male and female subjects were found only in the vertical eruption of mandibular incisors and maxiltary and mandibular molars. These results demonstrate that significant overjet and overbite corrections can be obtained with 6 months of maxillary protraction in combination with a fixed expansion appliance.

Role of protraction headgear in correction of a skeletal midface deficiency in a unilateral cleft lip and palate—an interim case report 3

Role of protraction headgear in correction of a skeletal midface deficiency in a unilateral cleft lip and palate—an interim case report 3

Changes in dentofacial morphology in skeletal Class III children treated by a modified maxillary protraction headgear and a chin cup: a longitudinal cephalometric appraisal

The purpose of the current report was to investigate cephalometrically possible orthopaedic effects of a modified maxillary protraction headgear (MPH) on dentofacial morphology in skeletal Class III female patients before and during the pubertal growth spurt period. Sixty-one patients were divided into three groups, the prepubertal (7-10 years, n = 20), the mid-pubertal (10-12 years, n = 22), and the late pubertal (12-15 years, n = 19) groups. Longitudinal record sets of subjects with acceptable good occlusion were used as the control. Patients were treated by protracting from the upper canine area. The mean ages at completion of the MPH treatment were 8.9, 11.3, and 13.3 years for the three test groups, respectively. The average treatment time was 1.1, 1.0, and 1.4 years for each of these groups. Lateral cephalograms at the start and completion of use of the MPH were collected. Annual differences were calculated from these paired records for each of 21 dentoskeletal variables in the test groups and compared to those of the control group. The pre- and mid-pubertal groups revealed significant increases in both the SNA (P < 0.01 and P < 0.001) and the maxillary length (Ptm-A/PP, P < 0.01), while the late pubertal group showed a less significant increase in the SNA (P < 0.05) alone. The decreased SNB, increased ANB and SNMP of the pre- and mid-pubertal groups was accounted for by the backward and downward rotation of the mandible. The results suggest possible orthopaedic effects of the MPH on dentofacial morphology in young females when it is applied before or during acceleration of the pubertal growth spurt.

A dental Class III malocclusion treated to a full-cusp Class II molar relationship

A case report of a Class III dental malocclusion superimposed on a straight skeletal pattern is presented. The patient was a 14-year-old girl with limited growth potential. This case included congenitally missing maxillary permanent lateral incisors, impacted maxillary permanent canines, and bilateral posterior open bites. The patient's soft-tissue profile was normally convex. In addition to her malocclusion, the patient had a history of difficulty breathing through the nose. The general treatment included palatal expansion, protraction headgear, and comprehensive edgewise orthodontic therapy.

Biomechanical and clinical considerations of a modified protraction headgear

The choice of treatment of children with developing skeletal Class III malocclusions has always posed a dilemma. Chin cups and various types of reverse headgears with elastics have been used in the past to minimize the growth and development discrepancy of the midface and the mandibular bones. In the present article, a critique of commonly used protraction devices is presented. A modified protraction headgear design and the biomechanical considerations of its clinical use are presented in this study. The clinical results show that a modified protraction headgear with a chin cup helps in the correction of moderately severe Class III malocclusions by the anterior displacement of the maxilla and maxillary dentition, and possibly restricting or changing the direction of the growth of the mandible. This headgear can also be used to correct axial inclinations and/or mesial displacement of posterior teeth.