Craniofacial Stability in Patients with Crouzon or Apert Syndrome after Le Fort III Distraction Osteogenesis

Craniofacial syndromes and class III phenotype: common genotype fingerprints? A scoping review and meta-analysis

Skeletal Class III (SCIII) is among the most challenging craniofacial dysmorphologies to treat. There is, however, a knowledge gap regarding which syndromes share this clinical phenotype. The aims of this study were to: (i) identify the syndromes affected by the SCIII phenotype; (ii) clarify the involvement of maxillary and/or mandibular structures; (iii) explore shared genetic/molecular mechanisms. A two-step strategy was designed: [Step#1] OMIM, MHDD, HPO, GeneReviews and MedGen databases were explored; [Step#2]: Syndromic conditions indexed in [Step#1] were explored in Medline, Pubmed, Scopus, Cochrane Library, WOS and OpenGrey. Eligibility criteria were defined. Individual studies were assessed for risk of bias using the New Ottawa Scale. For quantitative analysis, a meta-analysis was conducted. This scoping review is a hypothesis-generating research. Twenty-two studies met the eligibility criteria. Eight syndromes affected by the SCIII were targeted: Apert syndrome, Crouzon syndrome, achondroplasia, X-linked hypohidrotic ectodermal dysplasia (XLED), tricho-dento-osseous syndrome, cleidocranial dysplasia, Klinefelter and Down syndromes. Despite heterogeneity between studies [p < 0.05], overall effects showed that midface components were affected in Apert and Down Syndromes, lower face in Klinefelter Syndrome and midface and lower face components in XLED. Our review provides new evidence on the craniofacial characteristics of genetically confirmed syndromes exhibiting the SCIII phenotype. Four major regulatory pathways might have a modulatory effect on this phenotype. IMPACT: What does this review add to the existing literature? To date, there is no literature exploring which particular syndromes exhibit mandibular prognathism as a common trait. Through this research, it was possibly to identify the particular syndromes that share the skeletal Class III phenotype (mandibular prognathism) as a common trait highlighting the common genetic and molecular pathways between different syndromes acknowledging their impact in craniofacial development.

Craniofacial characteristics in Crouzon's syndrome: A systematic review and meta-analysis

The purpose of this meta-analysis was to strengthen the credibility of primary research results by combining open-source scientific material, namely a comparison of craniofacial features (Cfc) between Crouzon's syndrome (CS) patients and non-CS populations. All articles published up to October 7, 2021, were included in the search of PubMed, Google Scholar, Scopus, Medline, and Web of Science. The PRISMA guidelines were followed to conduct this study. PECO framework was applied in the following ways: Those who have CS are denoted by the letter P, those who have been diagnosed with CS via clinical or genetic means by the letter E, those who do not have CS by the letter C, and those who have a Cfc of CS by the letter O. Independent reviewers collected the data and ranked the publications based on their adherence to the Newcastle-Ottawa Quality Assessment Scale. A total of six case-control studies were reviewed for this meta-analysis. Due to the large variation in cephalometric measures, only those published in at least two previous studies were included. This analysis found that CS patients had a smaller skull and mandible volumes than those without CS.in terms of SNA° (MD = -2.33, p = <0.001, I2 = 83.6%) and ANB°(MD = -1.89, p = <0.005, I2 = 93.1%)), as well as ANS (MD = -1.87, p = 0.001, I2 = 96.5%)) and SN/PP (MD = -1.99, p = 0.036, I2 = 77.3%)). In comparison to the general population, people with CS tend to have shorter and flatter cranial bases, smaller orbital volumes, and cleft palates. They differ from the general population in having a shorter skull base and more V-shaped maxillary arches.

Three-dimensional analysis of the palatal morphology in growing patients with Apert syndrome and Crouzon syndrome

Patients with Apert syndrome or Crouzon syndrome present with severe defects in oral-maxillofacial growth and development. In this study, we conducted a quantitative three-dimensional (3D) analysis of the palatal morphology of patients with Apert syndrome and Crouzon syndrome. Four patients with Apert syndrome (average age, 11.0 ± 0.8 years) and five with Crouzon syndrome (average age, 10.1 ± 1.6 years) were investigated. The participants' maxillary dental casts were scanned and analyzed using 3D imaging. Palatal width, depth, cross-sectional area, and palatal angle (PW, PD, PCA, and PA, respectively) were measured, and standard scores were calculated based on sex- and age-matched Japanese standard values; the actual palatal surface areas (PSA) and palatal volumes (PV) were also measured. Our results show that patients with Apert syndrome and Crouzon syndrome had a very narrow PW (standard score: -3.79 and - 0.47, respectively). 3D analysis revealed that patients with Apert syndrome had a significantly shallower PD (standard score: -1.35) than those with Crouzon syndrome (standard score: 2.47), resulting in a smaller PCA (standard score: -5.13), PSA (5.49 cm² ), and PV (1.11 cm³ ) and larger PA (standard score: -0.12) than those in patients with Crouzon syndrome. This might be due to the former having a narrower and shallower palate caused by the predominant swelling of the palatal mucosa. These findings improve our understanding of the differences in palatal morphology between Apert syndrome and Crouzon syndrome patients.

Craniofacial morphology in Apert syndrome: a systematic review and meta-analysis

This meta-analysis aims to compare Apert syndrome (AS) patients with non-AS populations (not clinically or genetically diagnosed) on craniofacial cephalometric characteristics (CCC) to combine publicly available scientific information while also improving the validity of primary study findings. A comprehensive search was performed in the following databases: PubMed, Google Scholar, Scopus, Medline, and Web of Science, an article published between 1st January 2000 to October 17th, 2021. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed to carry out this systematic review. We used the PECO system to classify people with AS based on whether or not they had distinctive CCC compared to the non-AS population. Following are some examples of how PECO has been used: People with AS are labeled P; clinical or genetic diagnosis of AS is labeled E; individuals without AS are labeled C; CCC of AS are labeled O. Using the Newcastle-Ottawa Quality-Assessment-Scale, independent reviewers assessed the articles' methodological quality and extracted data. 13 studies were included in the systematic review. 8 out of 13 studies were score 7-8 in NOS scale, which indicated that most of the studies were medium to high qualities. Six case-control studies were analyzed for meta-analysis. Due to the wide range of variability in CCC, we were only able to include data from at least three previous studies. There was a statistically significant difference in N-S-PP (I2: 76.56%; P = 0.014; CI 1.27 to - 0.28) and Greater wing angle (I2: 79.07%; P = 0.008; CI 3.07-1.17) between AS and control subjects. Cleft palate, anterior open bite, crowding in the upper jaw, and hypodontia occurred more frequently among AS patients. Significant shortening of the mandibular width, height and length is the most reported feature in AS patients. CT scans can help patients with AS decide whether to pursue orthodontic treatment alone or to have their mouth surgically expanded. The role of well-informed orthodontic and maxillofacial practitioners is critical in preventing and rehabilitating oral health issues.

Extensive phenotyping of the orofacial and dental complex in Crouzon syndrome

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.

Change in Mandibular Position in Patients With Syndromic Craniosynostosis After Midfacial Advancement With Distraction Osteogenesis

OBJECTIVE

Characterize mandibular morphology in patients with syndromic craniosynostosis and document changes in mandibular position following midfacial advancement using distraction osteogenesis (DO).

DESIGN

Retrospective chart review and analysis of cephalometric radiographs.

SETTING

Tertiary care center.

PATIENTS

Patients with syndromic craniosynostosis who had midfacial advancement with DO at Boston Children's Hospital between 2000 and 2012. Mandibular morphology was characterized in 26 patients (15 boys and 11 girls) with a mean age of 11 years, 9 months. Pre- and postoperative analyses were performed for 17 (10 boys and 7 girls) of the 26 patients with a mean age of 11 years, 9 months.

MAIN OUTCOME MEASURES

Mandibular morphology and mandibular position. Data were compared to standard data from the Michigan Growth Study.

RESULTS

Comparison of preoperative mandibular measurements to standard data showed that patients with syndromic craniosynostosis have a shorter mandibular body and length and an obtuse gonial angle. Comparison of pre- and postoperative cephalograms showed that, following midfacial advancement with DO, the maxilla moved forward and the mandible moved backward and downward.

CONCLUSIONS

Patients with syndromic craniosynostosis have a smaller mandible length and obtuse gonial angle. Correction of midfacial hypoplasia with DO results in inferior and posterior mandibular movement. Clinicians can use this information to counsel patients regarding anticipated changes in facial profile and the need for adjunct procedures.