![]() During this last phase the objective is to keep the bone segment immobile to achieve a correct organization and condensation of the elements that will offer the characteristics of resistance to the newly formed tissue. 6–8 Thedistraction device is an expansion screw that has been universally graduated in such a way that every 360 degree turn will provide a 0.5 mm 18, 19 movement all this process is under biological principles such as: vascular preservation, adequatelatency period, distraction rhythm and consolidation period. These forces are applied with a distraction device on a bone area that has been previously weakened by corticotomy. Osteogenic distraction is a biological procedure of new bone formation by applying constant traction forces during a period of time. 11–14Its indications have broadened for the correction of facial asymmetries of diverse etiologies such as severe maxillaryand mandibular retrognathias. 8, 9 Its clinical and systematic application in craniofacial deformities began with McCarthy in 1992 9–11 mainly by using it in children with hemifacial microsomias for mandibular distraction. Ilizarov in 1950 made it popular in the field of trauma and orthopedics. This technique remained forgotten for several decades until Dr. Codevilla in 1905, when he performed femur osteotomies. Osteogenic distraction is a method for bone lengthening that allows the correction of deformities and bone deficiencies with the subsequent correction of the soft tissues 6 by means of a distracting appliance. Muscular skeletal system Radial abnormalities Zygomatic bone, maxillary and mandibular hypoplasiaĦ5% skeletal asymmetry Temporal, zygomatic, ramus y condilar hypoplasiaīroad nasal bridge with descended tip of the nose 3Īcral deformities associated with a facial disostosis allow it to be differentiated from the Treacher Collins syndrome, the Nager syndrome and other dysplasiasof the 1 st and 2 nd facial arch ( Table I ). 1–5 It can also be associated with vesicoureteral reflux or renal agenesis. Cardiovascular anomalies such as Fallot tetralogy and/or ventricular septum defect may be present. In the muscular skeletal system, it is characterized by radial anomalies, 75% of them being radial hypoplasia or aplasia, sinostosis of the carpal bones, absence of the 5 th metacarpian, agenesis of toes and anomalies of pelvic limbs. With craniofacial characteristics in 25% of the cases, it presents cygomatic and maxillaryhypoplasia, severe mandibular micrognathia, outwards and downwards palpebral fissures, absence of the lower lid eyelashes, lower lid coloboma, broad nasal bridge, depressed tip of the nose, limited mandibular movements secondary to alterations in the mandibular ramus and the temporomandibular joint, macrostomia, cleft lip and palate, soft palate agenesis, short soft palate, high and narrow palate, dysplasic earlobes, atresia of theear meatus, conductive deafness, enamel hypoplasia and oligodonthia. 1–5 It has a recessive autosomal genetic pattern and an alteration of the 9q32 chromosome, 1q12q21 deletion with an average neonatal birth rate of 20%, growth delay of 10% and usually normal intelligence. Nager’s syndrome is a preaxial acrofacial disostosis that consists in facial malformations associated with radial effects (absence of the radial or tibial axisfirst metacarpian and first toe). These are malformations associated with a hypoplasia or agenesis of the earlobe and mandibular hypoplasia among other facial deformities which can be found isolated or in association with other malformations. ![]() It belongs to the vast group of otofacialmandibular disostosis such as the Treacher Collins Syndrome, Nager’s Syndrome, Pierre Robin Anomaly, Hemifacial Microsomia, among others. ![]() Nager’s syndrome was described for the first time by Nager and De Reynier in 1948 there have been 100 cases reported in the literature up to now.
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