Speech performance in adult patients undergoing Invisalign treatment

To assess speech performance of adult patients undergoing orthodontic treatment with Invisalign.

Twenty-four adult patients with Invisalign (Invisalign group: 6 men, 18 women; average age; 34.88 years) and 20 adult patients with fixed labial appliances (fixed group: 5 men, 15 women; average age; 38.85 years) were evaluated. Speech was recorded immediately before delivery of the first set of clear aligners or bonding of labial appliances (T0), immediately after delivery or bonding (T1), and 2 months after delivery or bonding (T2). Speech was evaluated via a combination of three auditory analyses: (1) objective acoustic analysis through digital sonography, (2) semiobjective assessment by six speech and language pathologists, and (3) subjective assessment patient questionnaire.

The objective acoustic analysis showed a statistically significant difference over time from T0 to T1, T1 to T2, and T0 to T2 for Invisalign patients. The semiobjective analysis revealed a significant speech alteration from T0 to T1 and T1 to T2 for both groups, and from T0 to T2 in the Invisalign group. The subjective analysis showed a significant difference between means of Invisalign and fixed group patient perception at both T1 and T2.

Invisalign treatment significantly affected speech, and although patients experience some level of adaptation, speech does not return to normal after 2 months of treatment.