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

Area of Science:

• Craniofacial morphology
• Genetics
• Orthodontics

Background:

• Down syndrome (DS) is a genetic disorder associated with characteristic craniofacial features.
• Understanding these cephalometric variations is crucial for clinical management and treatment planning.

Purpose of the Study:

• To systematically evaluate and compare the craniofacial cephalometric characteristics of individuals with Down syndrome (DS) against healthy controls.
• To synthesize existing cephalometric data through meta-analysis.

Main Methods:

• A comprehensive electronic literature search was conducted across major databases (PubMed, Embase, Scopus, etc.).
• Studies were selected based on PRISMA guidelines and analyzed using the Newcastle-Ottawa Scale.
• A meta-analysis was performed on seven case-control studies, focusing on cephalometric measurements reported in at least three studies.

Main Results:

• Individuals with DS showed significantly reduced anterior and posterior cranial base lengths (SN, SBa, BaN), effective maxillary length (CoA), anterior facial height (NMe), and posterior facial height (SGo).
• The ANB angle was also significantly lower in the DS group.
• No significant differences were observed in SNA and SNB angles between DS and control groups.

Conclusions:

• Individuals with Down syndrome present with a shorter, flatter cranial base and reduced mid-face dimensions.
• These findings indicate a tendency towards a prognathic profile and flattened facial profile in the DS population.
• Cephalometric analysis reveals significant craniofacial differences in individuals with DS compared to the general population.