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
6 resultados
Resultados de Busca
Agora exibindo 1 - 6 de 6
- Racial disparity of Crouzon syndrome in maxilla and mandible(2020) LU, X.; FORTE, A. J.; FAN, F.; ZHANG, Z.; TANG, L.; YANG, B.; ALPEROVICH, M.; STEINBACHER, D. M.; ALONSO, N.; PERSING, J. A.The racial disparity of facial features in craniosynostosis patients is not fully understood. The aim of this study was to explore the difference in maxillary and mandibular morphology and spatial position in Asian and Caucasian Crouzon syndrome patients. Ninety-one computed tomography scans were included (12 Asian Crouzon syndrome patients, 22 Asian controls; 16 Caucasian Crouzon syndrome patients, 41 Caucasian controls) and measured using Materialise software. The maxillary and mandibular volumes of Asian patients were both reduced by 19% (P = 0.102 and P = 0.187), and those of Caucasian patients were reduced by 15% (P = 0.142) and 14% (P = 0.211) when compared to the respective race-specific controls. Maxilla length of Asian patients was reduced by 6.36 mm (14%, P = 0.003), while the reduction in Caucasian patients was 4.88 mm (10%, P = 0.038). ANS was retracted 11.99 mm (P < 0.001) in Asian patients and 11.54 mm (P < 0.001) in Caucasian patients. The ANB angle was narrowed by 13.17 degrees (P < 0.001) in Asian patients compared to Asian controls, and by 7.02 degrees (P < 0.001) in Caucasian patients compared to Caucasian controls. The retrusive midface profiles of Asian and Caucasian Crouzon syndrome look similar; both result from the combined effect of hypoplastic size and backward displacement. However, the insufficiency was found to be more a failure of the anteroposterior maxillary length in Asian patients, and more due to posterior maxillary positioning in Caucasian patients. Therefore, prognathism in Crouzon syndrome patients is more likely caused by displacement rather than elongation of mandibular length in both races. Crouzon syndrome results in the same extent of overall volume deficiency of the maxilla and mandible in these races.
- Racial disparity in orbital morphology and spatial relations in unoperated Crouzon patients(2021) LU, X.; FORTE, A. J.; FAN, F.; ZHANG, Z.; TENG, L.; YANG, B.; ALPEROVICH, M.; STEINBACHER, D. M.; ALONSO, N.; PERSING, J. A.The altered orbital morphology of patients with Crouzon syndrome could have an impact on the planning of treatment in diverse populations, in spite of the confounding influences of different cranial suture synostosis. This study attempted to explore the differences in orbital characteristics between Asian, Caucasian patients with Crouzon syndrome, associated pansynostosis. Eighty-six preoperative computed tomograms (CT) were included (Asian Crouzon syndrome: n=10; Asian controls: n=24; Caucasian Crouzon syndrome: n=19; Caucasian controls: n=33) and measured using Mimics software (Materialise). Unique cephalometric measurements related to orbital morphology and position were designed. Crouzon syndrome and race both have interactive effects on protrusion of the globe (p=0.009) and medial horizontal angle (p=0.012) in the assessment of orbital morphology. They also interact in the width of the ethmoid sinus (p=0.009) and influence bilateral orbital relations. The anteroposterior orbital roof in Caucasian patients with Crouzon syndrome was shortened by 4.09 mm (p=0.002) compared with Caucasian controls. However, in Asian patients this dimension developed normally. The anteroposterior orbital floor was significantly reduced to a similar extent in both Asian and Caucasian Crouzon patients (both p<0.001). The visual axes in Caucasian patients with Crouzon showed more inferior rotation, by 4.38 degrees (p=0.031) than they did in Caucasian controls, but did not achieve a statistically significant difference in other comparisons. The effect of Crouzon syndrome on orbital malformation and placement is influenced by race, especially structures related to the ethmoid sinus. Asian patients need greater infraorbital advancement for better correction of orbital proptosis and aesthetic benefits, but may require less fronto-orbital advancement than Caucasian patients.
- Growth patterns of the airway in Crouzon syndrome patients with different types of cranial vault suture synostosis(2021) LU, X.; FORTE, A. J.; WILSON, A.; PARK, K. E.; ALLAM, O.; ALPEROVICH, M.; STEINBACHER, D. M.; TONELLO, C.; ALONSO, N.; PERSING, J. A.The severity of obstructive respiratory difficulty varies among affected Crouzon syndrome patients. The aim of this study was to investigate the correlation between the restricted airway volume in Crouzon syndrome and the associated type of cranial vault suture synostosis. Computed tomography scans of 68 unoperated Crouzon syndrome patients and 89 control subjects were subgrouped into four types: type I, bilateral coronal synostosis; type II, sagittal synostosis; type III, pansynostosis; type IV, perpendicular combinations of synostoses. Measurements were made using Mimics software. Of type I Crouzon patients, 42% had a restricted nasal airway (P = 0.002), while the pharyngeal airway volume was not significantly reduced. Type II Crouzon patients grew normal segmental airway volumes. Crouzon patients of type III developed simultaneously reduced nasal and pharyngeal airway volumes in infancy, by 38% (P = 0.034) and 51% (P = 0.014), respectively. However, the nasal airway achieved a normal volume by 2 years of age without any intervention, while the pharyngeal airway remained significantly reduced up to 6 years of age, by 42% (P = 0.013), compared to controls. Type IV Crouzon patients developed a reduced nasal airway volume (32%, P = 0.048) and a non-significant restricted pharyngeal airway (18%, P = 0.325). Airway compromise in Crouzon syndrome is variable when associated with different craniosynostosis fusion patterns. Type II (sagittal synostosis) Crouzon patients grew a normal nasopharyngeal airway volume. Those with types I (bicoronal synostosis) and IV (perpendicular synostoses) had significantly restricted nasal airways and a tendency towards a reduced pharyngeal volume. Type III (pansynostosis) Crouzon infants had the worst restriction of both airways, although there was some improvement with age.
- Orbit, zygoma, and maxilla growth patterns in Crouzon syndrome(2019) LU, X.; FORTE, A. J.; SAWH-MARTINEZ, R.; WU, R.; CABREJO, R.; STEINBACHER, D. M.; ALPEROVICH, M.; ALONSO, N.; PERSING, J. A.The facial malformations of Crouzon syndrome involve the entire cranioorbito-zygomatic region. The detailed sequence of changes in orbit, zygoma, and maxilla over time, the mutual influence among these three anatomical structures, and their relationship with the cranial base were studied to determine the sequence and timing of deformity. Preoperative CT scans of 36 patients with Crouzon syndrome (mean age 10.84 +/- 14.70 years; 14 male, 22 female) and CT scans of 54 control subjects (mean age 8.53 +/- 13.22 years; 29 male, 25 female) were divided into five subgroups by age: 0-6 months, 6 months-2 years, 2-6 years, 6-18 years, and 18-62 years. Craniofacial morphometric cephalometrics were analyzed using Materialise software. Crouzon orbit anteroposterior length was shorter before 6 months (P = 0.021) and remained shorter into adulthood (P < 0.001). Globe projection was greater across all age subgroups (P < 0.001), reaching a peak at 6 months to 2 years (P < 0.001). The increased medial orbital width was the most remarkable and persistent secondary deformity (P < 0.001). The zygoma anterior protrusion was retruded before 6 months of age (P < 0.001), but then improved gradually. The width of maxilla was greater by 24% in the Crouzon cohort (P < 0.001), with a difference of 16% before 6 months (P = 0.024), and was developed earlier than the shortened anteroposterior length. Crouzon high and shallow orbital walls are distinctive. Maxillary widening developed before the malformation of sphenoid. The anteroposterior position of zygoma is likely a principal deformity, rather than a reflection of the intrinsic shape of the bone.
- 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.
- Enlarged anterior cranial fossa and restricted posterior cranial fossa, the disproportionate growth of basicranium in Crouzon syndrome(2019) LU, Xiaona; FORTE, Antonio Jorge; STEINBACHER, Derek M.; ALPEROVICH, Michael; ALONSO, Nivaldo; PERSING, John A.Crouzon syndrome patients develop normal intracranial volume and potential restricted posterior cranial fossa volume with growth. This study aims to trace the segmental anterior, middle and posterior cranial fossae volume, and structural morphology in these patients, in order to help discern more focused and individualized surgical treatment plan. Ninety-two preoperative CT scans (Crouzon, n = 36; control, n = 56) were included, and divided into 5 age related subgroups. CT scans were measured using Mimics and 3-matics software. Overall, Crouzon syndrome patients grew to a 27% (p = 0.011) increased anterior cranial fossa volume and a 20% (p = 0.001) decreased posterior cranial fossa volume, with normal middle cranial fossa and entire intracranial volume measurement. The posterior cranial fossa of Crouzon syndrome initially developed significantly reduced volume (19%, p = 0.032), compared to normals, from 6 months of age, and remained reduced thereafter. The 7.63 mm shortening of posterior cranial fossa length contributed most to the shortened entire cranial length (9.30 mm, p = 0.046). Although the entire cranial volume of Crouzon syndrome is normal overall, the segmental anterior, middle and posterior cranial fossae developed disproportionately. The early significant and lifelong restricted posterior cranial fossa addresses the importance of early posterior cranial expansion. Ideally expansion would have vectors in all three dimensions. (C) 2019 Published by Elsevier Ltd on behalf of European Association for Cranio-Maxillo-Facial Surgery.