Influence of vocal fold scarring on phonation: predictions from a finite element model.
OBJECTIVE
A systematic study of the influence of vocal fold scarring on phonation was conducted. In particular, phonatory variables such as fundamental frequency, oral acoustic intensity, and phonation threshold pressure (PTP) were investigated as a function of the size and position of the laryngeal scar.


METHODS
By means of a finite element model of vocal fold vibration, the viscoelastic properties of both normal and scarred vocal fold mucosae were simulated on the basis of recent rheological data obtained from rabbit and canine models.


RESULTS
The study showed that an increase in the viscoelasticity of the scarred mucosa resulted in an increase in fundamental frequency, an increase in PTP, and a decrease in oral acoustic intensity. With regard to positioning of the scar, the PTP increased most significantly when the scar was within +/-2 mm of the superior-medial junction of the vocal folds.


CONCLUSIONS
The systematic data obtained in this investigation agree with the general clinical experience. In the future, these findings may be further validated on human subjects as newly emerging technologies such as linear skin rheometry and optical coherence tomography allow the histologic and viscoelastic properties of the normal and scarred vocal fold mucosae to be measured in the clinic.
Berry
David A
DA
Laryngeal Dynamics Laboratory, Division of Head and Neck Surgery, David Geffen School of Medicine, The University of California, Los Angeles, Los Angeles, California, USA.
Reininger
Haven
H
Alipour
Fariborz
F
Bless
Diane M
DM
Ford
Charles N
CN
D000818:Animals; D002921:Cicatrix / Q000503:physiopathology*; D004285:Dogs; D020342:Finite Element Analysis; D005544:Forecasting; D007818:Laryngeal Diseases / Q000503:physiopathology*; D010699:Phonation; D011817:Rabbits; D014827:Vocal Cords / Q000503:physiopathology*