Bone-borne Device Research Articles

Evaluation of surgically assisted rapid maxillary expansion with or without pterygomaxillary disjunction based upon preoperative and post-expansion 3D computed tomography data

PURPOSE, METHODS: This study (50 patients; Ø 25 years) compared surgically assisted rapid maxillary expansion (SARME) with (+/-PP) to SARME without pterygomaxillary (-PP) disjunction due to dentoskeletal effects in 3D CT preoperatively and Ø 11 weeks post-expansion. In t test, SARME-PP declined in transverse width from anterior to posterior but more symmetrically than SARME+PP. It produced more segmental inclination and vestibular bone resorption in the premolars. SARME+PP also declined in transverse width from anterior to posterior but more asymmetrically with an extreme convergence to the molars. It produced more segmental inclination and vestibular bone resorption (second molar) in the molars and a palatal bone plate thickness increase in the second premolar. With variance analysis, a further differentiation between the two independent groups due to secondary variables was made: SARME+PP produced the biggest decline in transverse width (patients <20 years) and the biggest segmental outward inclination from anterior to posterior in patients with bone-borne devices. SARME-PP in patients <20 years and SARME+PP in patients >20 years both produced the biggest lateral pterygoid bending. Pterygomaxillary disjunction should be based on patient age and individual requirements, i.e., in patients <20 years (SARME-PP) and >20 years (SARME+PP).

Comparison of Tooth- and Bone-Borne Devices in Surgically Assisted Rapid Maxillary Expansion by Three-Dimensional Computed Tomography Monitoring

Comparison of bone-borne (BB) versus tooth-borne (TB) distraction in surgically assisted rapid maxillary expansion, secondary variables were bipartite (2S) or tripartite (3S) osteotomy, pterygomaxillary osteotomy (+PP) or not (jPP), and age (920 years old [920] and G20 years old [G20]). Fifty patients received three-dimensional computed tomography examination preoperatively and after expansion; 24 had BB, and 26 had TB distraction. Predefined preoperative landmarks versus postexpansion positions were assessed in multiplanar viewing. Bone-borne devices had bigger overall skeletal and dental maxillary expansion declining from anterior to posterior, more asymmetric expansion, less vestibular bone resorption, and less dental tipping; TB devices showed similar dorsal decrease in transverse skeletal and dental maxillary expansion from anterior to posterior, more vestibular bone resorption, particularly in the premolars, and more dental tipping. Bone-borne 3S +PP G20 had the biggest decrease in transverse skeletal widening and biggest segmental outward inclination; BB 3S +PP 920 had the biggest decline in transverse dental widening; TB 2S YPP G20 had the biggest segmental inward inclination; BB 2S YPP 920 had the biggest dental tipping; BB 2S G20 had the biggest vestibular bone resorption in molars; and TB 3S 920 and BB YPP had the biggest vestibular bone resorption in premolars. There was a significant correlation between transverse widening and segmental inclination; that is, a bigger amount of transverse widening provokes less segmental inclination.

Outcome of Mandibular Symphyseal Distraction Osteogenesis With Bone-Borne Devices

Mandibular symphyseal distraction osteogenesis (DO) is an alternative to the orthodontic treatment to resolve mandibular anterior width deficiencies or dental crowding. Different types of devices (tooth-borne, bone-borne, and hybrid device) have been used until now. The aim of this clinical study was to report our results with bone-borne device and compare them with previous studies' data to improve our symphyseal distraction protocol and future results. Fourteen patients were treated with symphyseal DO during a 10-year period. Two types of bone-borne distractors have been used. We evaluated morbidity and stability in the short- and long-term (from 12 to 24 months) follow-up, with clinical and radiological examinations. Appropriate symmetrical distraction of both basal and alveolar bone was obtained for all the patients, but correction of the discrepancy failed in 1 case. Mucosa irritation was the main problem. None of the patients presented with local infection. One temporomandibular joint dysfunction occurred during the distraction period, and 1 patient with preoperative temporomandibular joint dysfunction had his symptoms resolved in the long-term follow-up. In 1 case, a root exposure occurred during osteotomy, resulting in an osteogenesis delay. Considering the previous data of the literature and our clinical experience, mandibular symphyseal distraction is a safe alternative to orthodontic and previous surgical treatments, with low morbidity and stable long-term results. Bone-borne device is expected to assert stable results in the long term but with higher morbidity, compared with tooth-borne device. Both surgical techniques and devices have to improve, to assess the superiority of mandibular symphyseal DO to incisor-crowding treatment.

Comparison of different orthodontic devices for mandibular symphyseal distraction osteogenesis: A finite element study

In this study, we aimed to analyze the displacement field and the level of stability for a human mandible that had symphyseal distraction osteogenesis. The mandible was fitted with various orthodontic devices: tooth borne, bone borne, and hybrid. Three-dimensional nonlinear finite element analyses were performed to study differences between the nominal aperture of the device and the actual mandibular distraction. Furthermore, displacement fields of the mandibular arch evaluated with and without mastication forces were compared to determine the level of stability of each appliance. Computed tomography scan images of the mandible were processed to create the finite element model, which was completed by modeling the distraction device. Three cases were considered: the distraction device attached to the first molar and the first premolar (tooth borne), to the canine and basal bones (hybrid), or only to the basal bone (bone borne). The nominal aperture of each device was 2 mm. Mandibular displacements in the mastication phase were analyzed in the case of unilateral occlusion on the second premolar. Tooth-borne and hybrid devices allow orthodontists to better control the effective displacement transferred to the mandible by the distractor. Displacements of the mandibular arch were closer to the nominal aperture of the distractor than in the case of the bone-borne device. Hybrid devices were more stable under functional loads. However, parasitic rotations of the mandibular arms caused by mastication might counteract the benefits of distraction.

Reliable Surgically Assisted Rapid Palatal Expansion by Maxillary Widening Device

For surgically assisted rapid palatal expansion, bone-borne as well as tooth-borne devices to widen the maxilla are commonly used, both revealing advantages and disadvantages. In the area of bone-borne devices, several new designs have been introduced during the last years as an alternative to the tooth-borne Biederman-Hyrax screw. However, with these new distractors, new problems occurred. Therefore, we designed the Maxillary Widening Device (MWD; Normed, Tuttlingen, Germany), a new bone-borne distractor, being not only user-friendly but also universally applicable. We have used this device since 2005 in patients with upper jaw compression, and the MWD turned out to be easy and quick to insert. Using a minimal surgical approach such as the modified Le Fort I osteotomy, operation time was low. Fixating as well as activating the distraction cylinder turned out to be very user-friendly. The removal of the device after the retaining period was also unproblematic, and the later forming of the dental arch was good to satisfying in all patients.

Conventional bone-anchored palatal distractor using an orthodontic palatal expander for the transverse maxillary distraction osteogenesis: technical note

Surgical-assisted rapid palatal expansion includes various treatment procedures for solving transverse maxillary deficiencies, especially in cases with a matured palatal suture. Recent introduction of the concept of distraction osteogenesis has contributed to generalize this useful treatment and to develop some bone-borne devices that will not cause the problems found in cases treated by tooth-supported palatal expander. This report shows a conventional bone-borne distractor using commercially available orthodontic palatal expansion screws. The distractor consists of 2 parts: one is a commercially available orthodontic palatal expansion screw (Hyrax type, Fan style) and another is a screw-ring, which is one of the attached parts of the mandibular distraction system. The bone screws are inserted transmucosally to the palatal bone via the screw-rings. The palatal distractor can be applied to varied palatal shapes and can expand the palate without any trouble. This conventional palatal distractor may contribute to generalize the transpalatal maxillary distraction osteogenesis for cases with maxillary teeth problems.

Experience with the transpalatal distractor in congenital deformities

The transpalatal distractor is a bone-borne device that should eliminate negative orthodontic side-effects of tooth-borne devices. The literature contains reports of several possible complications of the transpalatal distractor. In this retrospective study its use was evaluated in ten patients with various congenital craniofacial anomalies, including clefts. During placement of the transpalatal distractor it was noted that in extremely narrow maxillae the palatal bone is very thin, which makes the initial placement difficult and therefore less primary stability can be obtained. There is often a thick palatal mucosa, which makes placement of the abutment plates difficult and leaves hardly any space for the module itself. Finally, in patients with mental retardation it is difficult to exchange modules and re-fix abutment plates. In our group of ten patients with congenital deformities a 60% complication rate was observed. The transpalatal distractor seems not to be the ideal device for use in widening the maxilla in cases with congenital deformities.

The Rotterdam Palatal Distractor: introduction of the new bone-borne device and report of the pilot study

Transverse maxillary hypoplasia, in adolescents and adults, is frequently seen as an acquired deformity and in congenital deformities patients and can be corrected by means of surgically assisted rapid maxillary expansion. Traditionally, the distractors for expansion are tooth-borne devices, i.e. hyrax appliances, which may have some serious disadvantages such as tooth tipping, cortical fenestration, skeletal relapse and loss of anchorage. In contrast, with bone-borne distractors most of the maxillary expansion is orthopedic and at a more mechanically desired level with less dental side effects. A new bone-borne palatal distractor has been developed. By activation the nails of the abutments plates automatically stabilizes the device and no screw fixation is necessary anymore. This new distractor is presented and the data of five acquired deformity and eight congenital deformity patients that were treated with this distractor are reported.

Problems, obstacles and complications with transpalatal distraction in non-congenital deformities

Introduction: The transpalatal distractor is a bone-borne device that eliminates negative orthodontic effects during and after maxillary expansion. It produces virtually parallel expansion in the coronal plane. Orthodontic appliances can be installed at an earlier date than when tooth-borne expanders are used. Our aim was to improve the technique by reviewing the difficulties encountered during applications in the past. Patients and Methods: The files of 57 patients were analyzed for problems (difficulties requiring surgical intervention), obstacles (difficulties requiring surgical intervention but not interfering with the result), and complications (difficulties not resolved at the end of the treatment). Results: Twenty-nine difficulties occurred. In 25 cases they were considered to be a ‘problem’. Nine problems were surgery related and 16 problems were related to the distraction device itself (14 episodes of loosening of the module, two instances of loss of one osteosynthesis screw). ‘Obstacles’ occurred in three cases, i.e. loosening of an abutment plate. There was only one ‘complication’: unilateral infraorbital hyposensibility in a case of a high level corticotomy. Conclusion: The expansion goal was achieved in all patients. Loosening of the module proved to be the major cause of discomfort. The incidence of difficulties has lead to a change in the design of the hardware and in the surgical protocol. Copyright 2002 European Association for Cranio-Maxillofacial Surgery. Published by Elsevier Science Ltd. All rights reserved.