Mandibular morphology and distraction osteogenesis vectors in patients with Robin sequence.

The aims of this cohort study were to compare the mandibular morphology between patients with Robin sequence (RS) and controls, and to examine the effects of mandibular distraction osteogenesis (MDO) using different vectors. Measurements of the mandibles of 80 patients with RS and 46 controls aged< 90 days were made using computed tomography. The data were compared among isolated RS patients (n = 58), syndromic RS patients (n = 22), and controls. Patients with RS exhibited significantly shorter ramus and body lengths and larger symphyseal angles than controls (all P < 0.001). Patients with isolated RS had shorter body lengths (P < 0.001), while syndromic patients had shorter ramus and body lengths (both P < 0.001) than controls. Seventy RS patients underwent MDO. Pre-MDO (n = 37) and post-MDO (n = 29) mandibular measurements were compared between patients undergoing MDO with a vertical vector and those undergoing MDO with a horizontal vector. Polysomnography data from part of the cohort highlighted the effectiveness of both vectors. MDO with a horizontal vector conferred 11% and 36% increases in ramus and body length, respectively, while these increases were 34% and 27.5%, respectively, with a vertical vector. MDO with a vertical vector was effective in lengthening ramus and body components and should be considered in the presence of ramus hypoplasia.

MSX1 gene and nonsyndromic oral clefts in a Southern Brazilian population.

Nonsyndromic oral clefts (NSOC) are the most common craniofacial birth defects in humans. The etiology of NSOC is complex, involving both genetic and environmental factors. Several genes that play a role in cellular proliferation, differentiation, and apoptosis have been associated with clefting. For example, variations in the homeobox gene family member MSX1, including a CA repeat located within its single intron, may play a role in clefting. The aim of this study was to investigate the association between MSX1 CA repeat polymorphism and NSOC in a Southern Brazilian population using a case-parent triad design. We studied 182 nuclear families with NSOC recruited from the Hospital de Clínicas de Porto Alegre in Southern Brazil. The polymorphic region was amplified by the polymerase chain reaction and analyzed by using an automated sequencer. Among the 182 families studied, four different alleles were observed, at frequencies of 0.057 (175 bp), 0.169 (173 bp), 0.096 (171 bp) and 0.67 (169 bp). A transmission disequilibrium test with a family-based association test (FBAT) software program was used for analysis. FBAT analysis showed overtransmission of the 169 bp allele in NSOC (P=0.0005). These results suggest that the CA repeat polymorphism of the MSX1 gene may play a role in risk of NSOC in populations from Southern Brazil.

MSX1 gene and nonsyndromic oral clefts in a Southern Brazilian population

Nonsyndromic oral clefts (NSOC) are the most common craniofacial birth defects in humans. The etiology of NSOC is complex, involving both genetic and environmental factors. Several genes that play a role in cellular proliferation, differentiation, and apoptosis have been associated with clefting. For example, variations in the homeobox gene family member MSX1, including a CA repeat located within its single intron, may play a role in clefting. The aim of this study was to investigate the association between MSX1 CA repeat polymorphism and NSOC in a Southern Brazilian population using a case-parent triad design. We studied 182 nuclear families with NSOC recruited from the Hospital de Clínicas de Porto Alegre in Southern Brazil. The polymorphic region was amplified by the polymerase chain reaction and analyzed by using an automated sequencer. Among the 182 families studied, four different alleles were observed, at frequencies of 0.057 (175 bp), 0.169 (173 bp), 0.096 (171 bp) and 0.67 (169 bp). A transmission disequilibrium test with a family-based association test (FBAT) software program was used for analysis. FBAT analysis showed overtransmission of the 169 bp allele in NSOC (P=0.0005). These results suggest that the CA repeat polymorphism of the MSX1 gene may play a role in risk of NSOC in populations from Southern Brazil.

Tratamento cirúrgico de meningomielocele no período neonatal / Urgical trearment of meningomyelocele defects in neonatal period

As meningomieloceles são defeitos congênitos de fechamento do canal medular, com gravidade variável. Os defeitos são encontrados principalmente na região lombossacra e há hidrocefalia em 80-90% dos casos. O objetivo deste trabalho foi estudar uma série de pacientes operados por meningomielocele no período neonatal, no período de janeiro de 2001 a janeiro de 2003. Foram incluídos 22 pacientes no estudo, sendo 12 (54,5%) masculinos e 19 (86%) de etnia caucasiana. A maioria dos pacientes eram a termo (37,5±1,3 semanas) e com peso adequado para idade gestacional (2960,5±609,6 gramas). Foi realizada cesárea em 16 casos (72,7%). O fechamento foi executado da seguinte forma: primário em 5 casos (23%); "skin-over-skin" em 6 casos (27%); bipediculado fasciocutâneo bilateral em 5 casos (23%); bipediculado fasciocutâneo unilateral em 1 caso (5%); fasciocutâneo com pedículo superior em 2 casos (9%); bilobado fasciocutâneo em 1 caso (5%); fasciocutâneo em S em 2 casos (9%). Houve DVP em 18 casos (81,8%). As complicações ocorridas foram: deiscência de sutura (23%); necrose parcial (18%) e fístulas (14%). A técnica "skin-over-skin" e os retalhos fasciocutâneos são alternativas efetivas para o fechamento de meningomieloceles no período neonatal.

Purpose: To study the incidence surgical treatment oflargeth or acolumbar meningomyeloceles duringathree- year period in a Brazilian referral center. Patients and methods: We prospectively evaluated all patients submitted to surgical management of meningomyelocele by both the plastic surgery and neurosurgery teams of Hospital de Clínicas de Porto Alegre between September 2001 and August 2003. Results: Twenty four patients were included in this study, being 13 (54.2%) males and 21 (87.5%) of Caucasian ethnicity. Most patients were born at term (37,5±1,3 weeks) and with weight adjusted for gestacional age (2960,5±609,6 gram). The closing was executed of the following form: direct skin approximation in 5 cases (23%); "skin-over-skin" in 6 cases (27%); bilateral bipedicled fasciocutaneous flaps in 5 cases (23%);unilateral bipedicled fasciocutaneous flap sin 1 case (5%); superior pedicled asciocutaneous in 2 cases (9%); bilobed fasciocutaneous flap in 1 case (5%); bilateral fasciocutaneous flaps (S flap) in 2 cases (9%). V-P shunt was placed in 18 cases (81.8%). Suture dehiscence (23%); partial necrosis (18%) and fistulas (14%) were the main complications. Conclusion: Skin-over-skin and fasciocutaneous flaps are good alternative for reconstruction of meningomielocele sin the neonatalperiod.

The viability of revascularized calvarial bone graft in a pig model.

This study compared the vascularity and resorption of calvarial bone flaps based on an undisturbed pedicle and on a previously (4 weeks) detached pedicle of the superficial fascia (galea) and periosteum and free calvarial bone grafts. Nine adult pigs were used, in three of which a silicone rubber compound was injected intravascularly immediately after the transfer confirmed the vascularity of both pedicled bone flaps. In six pigs, volume changes were assessed intraoperatively by a water displacement method and also 12 weeks postoperatively. Both pedicled bone flaps preserved their original volume, whereas free skull grafts showed approximately 50% of volume loss (p less than 0.001). Decalcified hematoxylin and eosin sections of the specimens obtained 12 weeks postoperatively showed a normal calvarial appearance in both pedicled bone flaps and extensive fibrous tissue infiltration into free grafts. It is suggested that a previous detachment of galea and periosteum does not interfere with the use of vascularized calvarial bone graft, which may provide a more predictable result than a free bone graft.

Comparison of inorganic bovine bone mineral particles with porous hydroxyapatite granules and cranial bone dust in the reconstruction of full-thickness skull defect.

Twenty adult rabbits were used to evaluate the biocompatibility and osteoconductivity of Bio-Oss, an inorganic bovine bone mineral, in the reconstruction of full-thickness skull defects. Skull defects were treated with either autogenous bone dust, porous hydroxyapatite granules, Bio-Oss particles, or were left untreated as controls. Histological examination of decalcified sections showed incorporation of Bio-Oss into the host tissue without a significant inflammatory reaction. Measurement of the profile area occupied by the bone revealed that Bio-Oss, hydroxyapatite, and the control had the same amount of bone ingrowth, whereas autogenous bone dust produced a greater amount of bone (p < 0.01). We conclude that Bio-Oss, like porous hydroxyapatite, has sufficient osteoconductive properties and can also be used as a bone substitute material.

The vascular anatomy of the galeal flap in the interparietal and midline regions.

The potential extension of the galeal flap in the interparietal area was studied on 17 fresh human cadaver heads by intravascular dye injection technique. It was demonstrated that an ipsilateral superficial temporal artery that supplies the galeal flap does not cross the midline or anastomose with the contralateral superficial temporal artery but ensures the survival of a flap extended up to 1 cm proximal to the sagittal suture line. The width of the temporoparietal flap can be extended up to 15 cm, depending on the vascular pattern of the superficial temporal artery. When required, the lateral extension may provide the required soft-tissue bulk despite the reduced flap length.

The volume limitation of the galeal temporalis flap in facial augmentation.

Galeal temporalis flaps based on the superficial temporal vessels have been used for facial augmentation and can be extended to the contralateral side beyond the midline in order to achieve maximum volume. In five patients, the volumes of extended galeal flaps were measured intraoperatively using a water displacement method. The calculated volume varied between 28 and 38 cm3. Experience with this flap showed satisfactory results with no complications; therefore, it is concluded that the extended galeal temporalis flap may be a first choice in the correction of facial soft tissue deficits less than 40 cm3. Clinical cases are presented.

Maxillectomy in childhood.

A maxillectomy in the upper part of the maxilla is an uncommon operation in childhood. The authors comment on the clinical evolution, the related pathologies and the surgical techniques employed in the treatment of eight patients.