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Distraction osteogenesis of the ascending ramus for mandibular hypoplasia using extraoral or intraoral devices: A report of 8 cases
... The primary surgical objective in the management of mandibular hypoplasia is to establish functional and aesthetic facial anatomy that remains stable long term [7]. Bone regeneration by distraction has become an accepted method of treatment of congenital and acquired mandibular hypoplasia. ...
... Distraction osteogenesis has been indicated in congenital micrognathia to lengthen the mandible in growing children, to widen the mandible in a child with hypoglossia-hypodactyly syndrome, also used to advance and lengthen the maxilla and midface [6]. The main advantages of distraction osteogenesis are progressive distension of all the soft tissue, resulting in facial symmetry [3] and large skeletal movements are possible without bone grafting [7]. ...
Distraction osteogenesis is a very useful technique for various facial asymmetries. It is commonly used to lengthen the hypoplastic maxilla and mandible. Condylar hypoplasia plays a major role in creating facial asymmetry in a growing child. In such case there will be facial asymmetry with chin deviation and occlusal cant. We report two cases of acquired unilateral condylar hypoplasia and its treatment with simultaneous distraction osteogenesis of maxilla and mandible to correct facial asymmetry and occlusal cant.
... Different DO devices for treating alveolar ridge deformities in animal and human studies were subsequently described by other authors. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] For the last decade, DO has been used intraorally to create bone for implant placement. In 1996, Block et al 22 and Chin and Toth 23 reported on the use of DO for site development prior to implant placement. ...
... DO has proven to be a predictable method for vertical ridge augmentation. [24][25][26][27]30,33,35,40 Two recent prospective studies documented average vertical gains following DO of 6.5 mm (range, 3 to 15 mm) 33 and 7 mm (range, 5 to 9 mm). 40 A case report used DO to treat an atrophied alveolar ridge in the anterior mandible of a 30-year-old woman and reported that "a vertical augmentation of 7 mm had been achieved." ...
Distraction osteogenesis (DO) is the latest addition to the variety of alveolar ridge augmentation procedures used to increase the volume of bone prior to implant placement. Thirty DO procedures were performed in 30 patients using 17 intraosseous and 13 extraosseous devices to augment deficient alveolar ridges. Fifty-five implants placed in the distracted bone were followed for a period of 34 to 60 months after loading. Five implants failed, for a 90.9% success rate. Vertical augmentation ranged from 3.5 to 13.0 mm (average, 7.8 mm). At least one complication was encountered, requiring additional hard or soft tissue surgery, in each of the 30 reported cases. This paper reviews complications encountered in the DO-treated patients, suggesting solutions and measures to prevent these problems.
Maxillary hypoplasia is a common developmental problem in cleft lip and palate deformities. Since 1970s these deformities have traditionally been corrected by means of orthognathic surgery. Management of skeletal deformities in the maxillofacial region has been an important challenge for maxillofacial surgeons and orthodontists. Distraction osteogenesis is a surgical technique that uses body’s own repairing mechanisms for optimal reconstruction of the tissues. We present four cases of anterior maxillary distraction osteogenesis with tooth borne distraction device-Hyrax, which were analyzed retrospectively for the efficacy of the tooth borne device-Hyrax and skeletal stability of distracted anterior maxillary segment.
The purpose of this report is to show the feasibility and potential advantages of using internal devices for distraction osteogenesis in the management of maxillofacial skeletal deficiencies.
Distraction osteogenesis was used to correct a variety of maxillofacial skeletal deformities in five patients. One patient underwent bilateral Le Fort III advancement aided by distraction, three patients underwent mandibular ramus lengthening, and one patient underwent segmental alveolar reconstruction by distraction. The devices were activated by either a transcutaneous or transmucosal pin. After achievement of the desired skeletal transport, the activating pins were disengaged and removed from the distraction device. This allowed the distraction device to remain submerged and to stabilize the site of the consolidating bone.
All patients achieved lengthening of their jaws. However, premature consolidation was noted in two patients, and one patient had significant relapse.
Development of internal distraction devices is important to address the limitations of currently available biphasic systems. Potential benefits of internal devices include 1) elimination of skin scarring caused by translation of transcutaneous fixation pins, 2) improved patient compliance during the fixation or consolidation phase because there is no external component, and 3) improved stability of the attachment of the device to the bone.
Servicio de Cirugia Plastica y Reconstructiva Hospital "Manuel Gea Gonzalez" Calzada de Tialpam 4800 Mexico, D.F. 14000 A modified technique for mandibular distraction is reported: An oblique corticotomy is made in the external cortex of the mandible at the level of the gonial angle. Two intraosseous stainless steel pins are inserted and are joined by a softer distraction screw. We make two corticotomies, one horizontal and one vertical, and insert three pins to achieve bidirectional distraction when the mandibular body and the ascending ramus are hypoplasic. This procedure has been used in 87 patients with unilateral hemifacial microsomia and 19 patients with bilateral mandibular hypoplasia. A mean elongation of 19 mm was obtained in the unilateral group. In the bilateral cases a mean vertical elongation of [7.5 mm and a mean horizontal elongation of 14 mm were obtained. A great improvement of the facial asymmetry was achieved in all the patients. The follow-up in this series varies from 3 months to 31/2 years (mean, 19 months in unilateral cases and 12 months in bilateral cases). No relapses have been observed. (Plast. Reconstr. Surg. 96: 825, 1995.) (C)1995American Society of Plastic Surgeons
Normal lengths of the vertical ramus, body, and angle of the mandible at different ages are presented. Before mandibular distraction is embarked on, the extent of the deficiency of the mandible is assessed. The length of the vertical ramus and body are measured on cephalometric radiographs or three-dimensional computed tomography (3D CT) scans. Deficiency of the length of the mandible is calculated. The position of the pin placement angle (from the horizontal ramus) is calculated by means of the following formula: 180 degrees minus mandibular angle times vertical ramus deficiency divided by total deficiency. Placing the pins correctly will result in correction of the vertical ramus and body deficiency of the mandible and the excessively obtuse angle of the mandible will become more acute.
Distraction osteogenesis has become an accepted method of treatment for patients requiring reconstruction of hypoplastic mandibles. We present a quantitative analysis of volumetric changes after distraction osteogenesis in a series of 10 patients. Group I (n = 5 patients, 3 unilateral craniofacial microsomia, 1 Goldenhaar syndrome, and 1 bilateral craniofacial microsomia) underwent unilateral distraction of the mandible. Group II (n = 5 patients, 1 Nager syndrome, 1 bilateral craniofacial microsomia, 1 developmental micrognathia, and 2 Treacher Collins syndrome) underwent bilateral distraction of the mandible. Predistraction and postdistraction axial and three-dimensional computed tomographic (CT) scans were digitized and transferred to a computer for analysis with image-processing software to determine the changes in volume of the mandible and bony regenerate. The CT-derived volume method was validated by scanning three dry cadaver mandible specimens and comparing the volume data with those derived from a water-displacement method. The difference between the two methods was less than 5 percent. The mean distracted length, as recorded from the calibrated device, was 22.6 mm in the 10 patients. In the unilateral distraction group, the mean increase in hemimandibular bone volume was 2.8 cc, with a mean percentage increase of 27 percent in the distracted hemimandible. In the bilaterally distracted patients, the mean increase in total mandibular volume was 7.9 cc, with a mean percentage increase in bone volume of 25 percent. This study represents the first attempt to quantify the increase in bone volume resulting from distraction osteogenesis. Quantitative volumetric analysis of CT scans is an accurate method to measure the amount of bone regenerate in patients undergoing distraction osteogenesis of the mandible or the extremities. The concept and utility of quantifying the volumetric changes in bone following distraction osteogenesis may become more important as multiplanar devices are developed and used in other areas of the craniofacial skeleton.
The theoretical basis for the treatment of hemifacial microsomia Treatment of Hrmifacial Micro somia
- Harvold Ep Mccarthy Jg
- J Schrribcr
- Karp
Harvold EP: The theoretical basis for the treatment of hemifacial microsomia. in Harvold EP (ed): Treatment of Hrmifacial Micro somia. New York. W. Liss. 1983 McCarthy JG, Schrribcr J, Karp N. et al: Lengthening the human mandible by gradual distraction. Plast Reconstr Sure, 89: 1, 1992