Longitudinal Recovery of Speech Motor Function Following Facial Transplantation: A Prospective Observational Study

Abstract

Objectives: Although facial transplantation is considered effective for restoring facial appearance, research on speech outcomes following surgery is limited. More research is critically needed to inform patients of expected rates and extent of recovery, and to develop interventions aimed at improving speech outcomes.

Methods: Four patients in early recovery (3 weeks-24 months postsurgery) and three patients in late recovery (36-60 months postsurgery) were included. Clinical measures of speech recovery, including speech intelligibility measured using the Sentence Intelligibility Test, a lip strength testing device (Iowa Oral Performance Instrument), and kinematic measures of lip and jaw function measured using high-resolution 3D optical motion capture were used to describe the rate and extent of functional speech and lip recovery, describe and compare the rate of functional speech recovery and kinematic lip and jaw changes in early and late stages of recovery, and explore the association between kinematic measures and functional speech.

Results: Speech intelligibility, speaking rate, and lip strength were below normative values in the first 2 years of postsurgery. Participants in the first 2 years of recovery demonstrated steeper slopes of improvement in clinical and kinematic measures than participants in the later stages of recovery (36-64 months). Gains in jaw range of movement and gains in lip speed and range of movement were significantly correlated with rates of sentence intelligibility improvement. Gains in lip strength were not associated with functional speech improvement.

Conclusions: These findings motivate ongoing work aimed at developing interventions for improving motor speech function in this population.

Level of evidence: 3 Laryngoscope, 132:2359-2367, 2022.

Keywords: facial transplantation; motor speech; speech kinematics; speech movement; speech recovery.