Relapse rate and magnitude of relapse after mandibular distraction osteogenesis (MDO) in adult retrognathic patients

Abstract

Objectives: The objective of the present study was to analyze the relapse rate and the magnitude of relapse after mandibular distraction osteogenesis (MDO) using cephalometric measurements. Materials and methods: The sample comprised 63 patients (49 women, 14 men) with moderate to severe mandibular retrognathia, mean age of 22.6 years, who underwent MDO between 2010 and 2021. Data were collected from CBCTs recorded preoperatively (T0), after the active distraction phase (T1), and 12 months after the distraction phase (T2). Two-dimensional cephalometry analyses were performed. Results: The mean cephalometric advancement was at T1 for mandibular body length (MBL) 10.30 mm, for mandibular unit length (MUL) 8.00 mm, and for SN-Pog 4.84°. At T2, MUL decreased by 0.26 mm (p = 0.14), and MBL by 0.22 mm (p = 0.39). A positive correlation between the magnitude of distraction and the magnitude of relapse was identified (MBL p = 0.045; MUL p = 0.002). Conclusions: MDO is a reliable method of advancing the mandible in retrognathic adult patients.

Keywords

• Mandibular distraction osteogenesis
• Relapse rate
• Magnitude of relapse