Extensive phenotyping of the orofacial and dental complex in Crouzon syndrome. (February 2018)

• Record Type: Journal Article
• Authors: Khominsky, Alexander; Yong, Robin; Ranjitkar, Sarbin; Townsend, Grant; Anderson, Peter J.
• Is Part Of: Archives of oral biology. Volume 86(2018)
• Page Start: 123
• Page End: 130
• Publication Date: 2018-02
• Subjects: Craniofacial phenomics -- Craniosynostosis -- FGFR2 -- Maxilla -- Mandible -- Tooth; Mouth -- Periodicals; Mouth -- Diseases -- Periodicals; Dentistry -- Periodicals; Electronic journals; 617.6005
• DOI: 10.1016/j.archoralbio.2017.10.022
• Languages: English
• ISSNs: 0003-9969

Abstract

Highlights: We investigated the phenotype of Crouzon syndrome ( FGFR2 C342Y/+ ) in a murine model. Hypoplasia was present in all three planes in the Crouzon maxilla and mandible. Bifid mandibular condyles were found in all Crouzon mandibles. Crouzon teeth were shorter mesiodistally and taller in crown height. A quarter of the Crouzon sample presented with expansion bone lesions. Abstract: Objectives: Fibroblast growth factor receptor 2 (FGFR2) C342Y/+ mutation is a known cause of Crouzon syndrome that is characterised by craniosynostosis and midfacial hypoplasia. Our aim was to conduct extensive phenotyping of the maxillary, mandibular and dental morphology associated with this mutation. Materials and methods: Morphometric data were obtained from 40 mice, representing two genotypes (Crouzon and wild-type) and two sexes (males and females) (n = 10 in each group). Dental analysis further categorised the first molars into the two jaws (maxillary and mandibular) (n = 20 in each group). Maxillary, mandibular and dental morphology was compared by analysing 23 linear landmark-based dimensions in three-dimensional micro-computed tomography reconstructions. Results: Compared with wild-type, Crouzon ( FGFR2 C342Y/+ ) maxillae were significantly shorter in maximum height, anterior and posterior lengths and middle width, but larger in posterior width ( p < 0.05 for height; p < 0.001 for other comparisons). In the Crouzon mandible, the ascending and descending heights, effective and mandibular lengths, and intercoronoid and intercondylar widths were significantly shorter, whereas intergonial width was larger ( p < 0.01 for intercondylar width; p < 0.001 for other comparisons). Crouzon teeth were significantly smaller mesiodistally, but larger in crown height ( p < 0.001 for each comparison). All Crouzon mice presented with bifid mandibular condyles and a quarter presented with expansive bone lesions in the mandibular incisor alveolus. Conclusions: Our findings of hypoplasia in all three planes in Crouzon maxillae and mandibles, together with the presence of bifid mandibular condyles and expansive bone lesions, may be relevant to maxillofacial surgery and orthodontics. Beyond skeletal effects, the FGFR2 C342Y/+ mutation is now implicated in affecting tooth development. This study's skeletal phenomics data also provides baseline data against which the effect of various treatments can now be assessed.