NIVALDO ALONSO
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Cirurgia, Faculdade de Medicina - Docente
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
4 resultados
Resultados de Busca
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- What Is the Difference in Cranial Base Morphology in Isolated and Syndromic Bicoronal Synostosis?(2020) LU, Xiaona; FORTE, Antonio Jorge; WILSON, Alexander T.; PARK, Kitae Eric; ALLAM, Omar; MOZAFFARI, Mohammad Ali; ALPEROVICH, Michael; STEINBACHER, Derek M.; ALONSO, Nivaldo; PERSING, John A.Background: The association of isolated craniosynostosis and the influence of syndromic forms confound the understanding of craniofacial morphologic development. This study attempts to clarify the individual influences of isolated bicoronal synostosis, Apert syndrome, and Crouzon syndromes on skull base morphology. Methods:: One hundred seventeen computed tomographic scans were included (nonsyndromic bicoronal synostosis,n= 36; Apert syndrome with bicoronal synostosis,n= 25; Crouzon syndrome with bicoronal synostosis,n= 11; controls,n= 45). Cephalometric measurements were analyzed using Materialise software. Results: Nonsyndromic bicoronal synostosis patients developed a shortened cranial base length, with a significantly shortened distance between nasion and sella (p= 0.005). The cranial base angles of nonsyndromic bicoronal synostosis in both the cranial side (N-S-BA) and facial side (N-SO-BA) increased significantly, by 17.04 degrees (p <0.001) and 11.75 degrees (p <0.001), respectively. However, both the N-S-BA and N-SO-BA angles of Apert syndrome and Crouzon syndrome were narrowed more than that of nonsyndromic bicoronal synostosis [by 12.11 degrees (p <0.001) and 12.44 degrees (p <0.001), respectively, in Apert syndrome; and by 11.66 degrees (p= 0.007) and 13.71 degrees (p= 0.007), respectively, in Crouzon syndrome]. However, there is no statistically significant difference of these two angles between Apert syndrome and Crouzon syndrome, when they were only associated with bicoronal synostosis. Contrary to the relatively normal subcranial space of nonsyndromic bicoronal synostosis, both Apert and Crouzon syndromes developed a reduced subcranial space. Conclusions: Isolated bicoronal synostosis resulted in a flattened cranial base, whereas Apert syndrome and Crouzon syndrome developed a normal cranial base angle when only associated with bicoronal synostosis. The syndromic skulls had additional significantly reduced subcranial space.
- Orbital and Periorbital Dysmorphology in Untreated Pfeiffer Syndrome(2022) LU, Xiaona; FORTE, Antonio Jorge; ALLAM, Omar; PARK, Kitae Eric; WILSON, Alexander; ALPEROVICH, Michael; STEINBACHER, Derek M.; TONELLO, Cristiano; ALONSO, Nivaldo; PERSING, John A.Background: Visual impairment secondary to orbital and periorbital dysmorphology is frequent in Pfeiffer syndrome patients. The etiopathogenesis of this aberrancy, however, remains unclear. Methods: Untreated Pfeiffer syndrome patients (n = 31) and normal control subjects (n = 43) were compared. Craniometric and volumetric analyses related to the orbital and periorbital anatomy were performed using Materialise (Leuven, Belgium) software. Results: Overall, orbital cavity volume of Pfeiffer patients is reduced by 28 percent (p < 0.001), compared to normal, starting before 3 months of age (p = 0.004). Globe volume was diminished by 10 percent (p = 0.041) before 3 months of age, yet tended to catch up thereafter. However, the retrobulbar soft-tissue volume remained smaller beyond 1 year of age (17 percent, p = 0.003). Globe volume projection beyond the bony orbit increased in all observed ages (82 percent, p < 0.001). The volumes of sphenoid bone, maxilla, and mandible proportionately were restricted by 24 to 25 percent (p = 0.003 to 0.035) before 3 months of age. The volume of maxilla and mandible gradually approximate normal; however, the sphenoid bone volume in Pfeiffer patients remains less than normal (p = 0.002) into childhood. The anteroposterior length of both the zygoma and the maxilla was reduced by 14 percent (p < 0.001). Anterior positioning of the zygoma is less by 23 percent (p < 0.001) in Pfeiffer patients overall, with anterior positioning of maxilla reduced similarly by 23 percent (p < 0.001). Conclusions: Pfeiffer syndrome patients develop decreased retrobulbar soft-tissue and globe volume, along with a restricted orbital cavity volume in infancy. Significant hypoplasia of the sphenoid bone is associated with more severe central facial (maxilla) retrusion, compared to lateral facial structures (zygoma).
- Orbitofacial morphology changes with different suture synostoses in Crouzon syndrome(2022) LU, Xiaona; FORTE, Antonio Jorge; JUNN, Alexandra; DINIS, Jacob; ALPEROVICH, Michael; ALONSO, Nivaldo; PERSING, John A.This study aims to investigate the influence of different cranial vault suture synostoses on orbital and periorbital morphological development in Crouzon syndrome. Computed tomography (CT) scans of Crouzon syndrome patients who had not undergone operation were subgrouped as follows: type I: bicoronal synostosis; type II: sagittal synostosis; type III: pansynostosis; type IV: perpendicular combinations of suture synostoses; and type V: bilateral squamosal synostosis. CT scans were measured using Materialise software. CT scans of 80 Crouzon syndrome patients and 72 normal controls were included. Orbital bony cavity volume was reduced in all subgroups (16-24%), including type V bilateral squamosal synostosis (16%, p = 0.003), although the reduction in type II sagittal synostosis Crouzon patients failed to reach statistical significance (p = 0.071). Globe volume was reduced only in type I bicoronal synostosis (9%, p = 0.018), while the retrobulbar soft tissue volume decreased in type III pansynostosis group by 11% (p = 0.005). Globe volume projection beyond the orbital rim was increased in all groups (p < 0.001), with the greatest increase in type IV perpendicular combination of sutures synostoses, by 100% (p < 0.001). The anteroposterior length of maxilla was significantly shortened in type I (10%, p = 0.028) and type III (9%, p = 0.022) but developed normally in other groups, although the maxilla was posteriorly displaced in all groups (all p <= 0.026). The influence of squamosal synostosis on craniofacial malformation is not equivalent to that of a major vault suture. Therefore, subtype suture fusion individualized surgical interventions, after initial occipital expansion, likely provide additional benefits in mitigating oculo-orbital disproportion.
- Cephalocranial Disproportionate Fossa Volume and Normal Skull Base Angle in Pfeiffer Syndrome(2021) LU, Xiaona; FORTE, Antonio Jorge; ALLAM, Omar; PARK, Kitae Eric; ALPEROVICH, Michael; STEINBACHER, Derek M.; TONELLO, Cristiano; ALONSO, Nivaldo; PERSING, John A.Background: Pfeiffer syndrome is a rare syndromic craniosynostosis disorder, with a wide range of clinical manifestations. This study aims to investigate the structural abnormalities of cranial fossa and skull base development in Pfeiffer patients, to provide an anatomic basis for surgical interventions. Method: Thirty preoperative CT scans of Pfeiffer syndrome patients were compared to 35 normal controls. Subgroup comparisons, related to differing suture synostosis, were performed. Results: Overall, the volume of anterior and middle cranial fossae in Pfeiffer patients were increased by 31% (P < 0.001) and 19% (P = 0.004), versus controls. Volume of the posterior fossa in Pfeiffer patients was reduced by 14% (P = 0.026). When only associated with bicoronal synostosis, Pfeiffer syndrome patients developed enlarged anterior (68%, P = 0.001) and middle (40%, P = 0.031) fossae. However, sagittal synostosis cases only developed an enlarged anterior fossa (47%, P < 0.001). The patients with solely bilateral squamosal synostosis, developed simultaneous reduced anterior, middle and posterior cranial fossae volume (all P <= 0.002). The overall skull base angulation, measured on both intracranial and subcranial surfaces, grew normally. Conclusion: Enlarged anterior cranial fossae in Pfeiffer syndrome children is evident, except for the squamosal synostosis cases which developed reduced volume in all fossae. Volume of the middle cranial fossa is influenced by associated cranial vault suture synostosis, specifically, sagittal synostosis cases develop normal middle fossa volume, while the bicoronal cases develop increased middle fossa volume. Posterior cranial fossa development is restricted by shortened posterior cranial base length. Surgical intervention in Pfeiffer syndrome patients optimally should be indexed to different suture synostosis.