IADR Abstract Archives
Orofacial and dental characteristics in Crouzon syndrome.
Objectives: Crouzon syndrome is a common genetic craniofacial disorder, characterised by craniosynostosis (the premature fusion of one or more sutures in the skull) and a short midface. It can lead to life-threatening neural, respiratory and feeding complications in children, and management can involve multiple invasive surgeries. FGFR2 mutations are a known cause of Crouzon syndrome and a necessary first step in understanding how patients will respond to treatment is better characterisation of the association between the genotype (genetic make-up) and phenotype (observable characteristics). We used a genetically-engineered mouse model to investigate the role of an FGFR2 mutation in the development of the orofacial and dental phenotype.
Methods: Forty mouse skulls, representing two genotypes (Crouzon syndrome and wild-type) and two sexes (males and females) (n = 10 in each group) were used. Maxillary, mandibular and dental morphology were compared between groups by analysing relevant landmark-based linear dimensions in three-dimensional micro-CT reconstructions.
Results: Compared to wild-type, Crouzon maxillae and mandibles were generally smaller, however mandibular parameters showed greater variations. Teeth were significantly narrower mesiodistally, however taller in crown height. Crouzon mice displayed bilateral bifid condyles in all cases and expansive bone lesions around mandibular incisors in about 25% of cases.
Conclusions: This study provides new insights into the effects of a FGFR2 mutation on the orofacial and dental phenotype. This research has the potential to improve clinical management of Crouzon syndrome, as the relationships between the maxilla, mandible and teeth, is critical in achieving successful functional and psychological outcomes. The new discoveries of bifid mandibular condyles and expansive bone lesions indicate complex actions of FGFR2 molecular pathways. Establishing baseline orofacial and dental features will assist in the development of more predictable and targeted molecular-based therapies for affected patients in the future.
Methods: Forty mouse skulls, representing two genotypes (Crouzon syndrome and wild-type) and two sexes (males and females) (n = 10 in each group) were used. Maxillary, mandibular and dental morphology were compared between groups by analysing relevant landmark-based linear dimensions in three-dimensional micro-CT reconstructions.
Results: Compared to wild-type, Crouzon maxillae and mandibles were generally smaller, however mandibular parameters showed greater variations. Teeth were significantly narrower mesiodistally, however taller in crown height. Crouzon mice displayed bilateral bifid condyles in all cases and expansive bone lesions around mandibular incisors in about 25% of cases.
Conclusions: This study provides new insights into the effects of a FGFR2 mutation on the orofacial and dental phenotype. This research has the potential to improve clinical management of Crouzon syndrome, as the relationships between the maxilla, mandible and teeth, is critical in achieving successful functional and psychological outcomes. The new discoveries of bifid mandibular condyles and expansive bone lesions indicate complex actions of FGFR2 molecular pathways. Establishing baseline orofacial and dental features will assist in the development of more predictable and targeted molecular-based therapies for affected patients in the future.