Mandibular morphology and distraction osteogenesis vectors in patients with Robin sequence

Area of Science:

• Craniofacial surgery
• Pediatric dentistry
• Orthodontics

Background:

• Robin sequence (RS) is a congenital condition characterized by mandibular hypoplasia.
• Understanding mandibular morphology in RS is crucial for effective treatment planning.
• Mandibular distraction osteogenesis (MDO) is a surgical technique used to correct severe mandibular hypoplasia.

Purpose of the Study:

• To compare mandibular morphology in patients with Robin sequence (RS) versus controls.
• To evaluate the efficacy of mandibular distraction osteogenesis (MDO) using different distraction vectors.

Main Methods:

• Cohort study involving 80 RS patients and 46 controls (aged <90 days).
• Computed tomography (CT) scans used for mandibular measurements.
• Comparison of MDO outcomes between vertical and horizontal distraction vectors.

Main Results:

• RS patients exhibited shorter ramus and body lengths and larger symphyseal angles than controls.
• Both isolated and syndromic RS patients showed significant mandibular shortening.
• MDO with a vertical vector resulted in greater ramus lengthening (34%) compared to a horizontal vector (11%).

Conclusions:

• Robin sequence is associated with distinct mandibular hypoplasia.
• Mandibular distraction osteogenesis is effective in correcting mandibular length in RS patients.
• Vertical vector MDO is particularly effective for ramus lengthening and should be considered for ramus hypoplasia.