Morphological characterization of zygomatic arch, maxilla and mandible in subjects with dysostosis mandibulofacial

Author(s)

Priscila Padilha Moura

• Document type: Doctoral Thesis
• Press: Bauru.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Bauru (FOB/SDB)
• Defense date: 2016-11-11

Examining board members

Roseli Maria Zechi Ceide; Maria Rita dos Santos e Passos Bueno; Christiano de Giacomo Carneiro; Antonio Richieri da Costa; Rita de Cássia Moura Carvalho Lauris

• Advisor: Roseli Maria Zechi Ceide; Daniela Gamba Garib Carreira

Abstract

Introduction: Mandibulofacial dysostoses are a genetically heterogeneous group of conditions characterized mainly by hypoplasia of the zygomatic arch, mandibular hypoplasia and ear anomalies. Purpose: Characterize the craniofacial morphology of different types of mandibulofacial dysostosis and investigate the anomalies in zygomatic arch, mandible, maxilla and mandibular condyle, by means of radiological evaluation. Methods: This study included 54 patients (with 25 female and 13 male) diagnosed with mandibulofacial dysostosis defined by professionals from Clinical Genetics Section and Molecular Biology by Hospital for Rehabilitation of Craniofacial Anomalies. The subjects underwent updating of clinical genetic and radiological evaluation by computed tomography (helical scan or cone beam). For morphological analysis, the acquired images were reconstructed in three dimensions and craniofacial structures were segmented in the Mimics software to assist in the description of the changes in the zygomatic arch, maxilla and mandible The analysis of clinical and morphological data was descriptive and in table form. Results: Thirty-two had genetic-clinical diagnosis of Treacher-Collins syndrome, 7 dysostosis mandibulofacial type Bauru, 4 dysostosis mandibulofacial Guion-Almeida type, 1 dysostosis mandibulofacial with alopecia and 10 with dysostosis mandibulofacial not defined.Morphological analysis showed hypoplasia of bone and zygomatic arch, maxilla and mandible in all evaluated individuals with high phenotypic variability. However, individuals with Treacher Collins syndrome presented in a more severe phenotype spectrum, Tessier cleft number were observed 6, 7 and 8, changes in mandibular condyles coronoides processes and mandibular ramus and body. The mandibulofacial dysostosis with alopecia showed agenesis of the temporal portion of the zygomatic arch, Tessier cleft number 8 (zygomatic process of the temporal bone), mandible hypoplastic and asymmetric, the condyles were broad and coronoides process hypoplastic. Mandibulofacial dysostosis Guion-Almeida type showed Tessier cleft number 7, facial asymmetry, mandibular hypoplasia with changes of condyle and coronoid process of anomaly, the mandibulofacial dysostosis type Bauru showed a well marked mandible hypoplasia with zygomatic arch hypoplastic and thin, mandibular hypoplasia, hypoplastic condyles and changes in the coronoid process and the cases with mandibulofacial dysostosis not defined had hypoplastic midface and varying degree of mandible and three cases showed skeletal changes, one case suggests cerebrocostomandibular syndrome, one case overlaps Treacher Collins syndrome, two cases overlapping clinical signs of dysostosis mandibulofacial Guion Almeida-type and the other three cases remain unclear. Conclusion: the radiological findings in Treacher Collins syndrome were more severe in the groups The radiological findings of mandibulofacial dysostosis Guion-Almeida type overlap those observed in Treacher Collins syndrome, the findings in mandibulofacial dysostosis Bauru type were lighter than the other groups and mandibulofacial dysostosis with alopecia presents a peculiar phenotype and for cases of dysostosis mandibulofacial not defined, molecular analysis is needed to aid in the diagnosis (AU)

• FAPESP's process: 13/19831-0 - Morphological characterization of the zygomatic arch, maxilla and mandible in individual with mandibulofacial dysostosis
• Grantee: Priscila Padilha Moura
• Support Opportunities: Scholarships in Brazil - Doctorate