• The Effect of Maxillary Features and Occlusal Parameters on "sh" Production in Control and Glossectomy Subjects

      Pedersen, Andrew David; Stone, Maureen L. (2017)
      This study examines the process by which the tongue articulates speech in glossectomy and control subjects using high resolution structural, and cine-MRI. Maxillary features and occlusal parameters are assessed in both groups to see if any effect on the amount of tongue volume displaced when contacting the anterior palate is noted. This volume amount is termed anteriority and measured against multiple variables. The independent variables include palate height, intercanine width, arch perimeter, orthodontic bicuspid extraction, overbite and overjet. The speech task of each subject is the sound "sh" extracted from a repeated word task. Results of the study showed statistically significant (p ≤ 0.05) differences in anteriority between glossectomy patients and controls, large versus small overbite, and an interaction between subject type and overbite. Data suggests having a larger overbite decreases the oral cavity size during "sh" sound and therefore increases tongue anteriority, especially in glossectomy subjects.
    • Effect of Maxillary Features on Tongue Anteriority in Glossectomy and Control Speakers

      Hwang, Jun Hyuk; Stone, Maureen L. (2015)
      This study examines the behavior of glossectomy (N = 15) and normal tongue (N =20) movement using combination of high-resolution and cine- MRI. The speech task "a souk" was used to measure anterior tongue displacement, termed "anteriority", from /uh/ to /s/. Effects on anteriority due to palate height, /s/ type, arch perimeter, canine width, and orthodontic extraction of teeth were measured on controls and patients. Results showed that all factors except canine width had no significant difference in anteriority of tongue. Canine width was significantly related to anteriority in an inverse relationship. The fact that arch perimeter is less important than canine width on anteriority is consistent with our understanding of the criticality of the location of the tongue tip, rather than the tongue body, in producing /s/. Data also suggests that less than average arch perimeter improves speech intelligibility in patients with T2 tumor of the tongue.
    • The Effects of Glossectomy and Palatal Dimension on Activity of the Tongue Muscles: A Quantitative MRI Analysis

      Lim, Ji Youn; Stone, Maureen L. (2016)
      Purpose: The purpose of this study was to compare the tongue muscle activity of glossectomy patients and normal controls and to determine which of the following factors - palate height, palate width, and tumor size (T1 vs. T2) - might influence muscle activity after glossectomy. Methods: Muscle shortening within the hemi-tongue of 12 controls and 9 glossectomy patients was measured during the elevation and retraction of the tongue from /s/ into the /uk/ of the word "a souk" using cine-MRI and tagged-MRI. The muscle length measurements were performed on the following five tongue muscle segments: 1) genioglossus posterior (GGp), 2) geniohyoid (GH), 3) transverse anterior (Ta), 4) transverse middle (Tm), and 5) transverse posterior (Tp). Results: The controls demonstrated significant asymmetric Ta and Tp muscle shortening with the larger side shortening more than the smaller side. The patients showed relatively symmetric muscle shortening on the native and the resected sides. High palate subjects showed greater GH shortening, while wide palate subjects showed greater GH and Ta shortening. No significant interaction was found between the effects of palate dimension and glossectomy on muscle shortening. A significant positive correlation between shortening was found in five pairs of muscles in controls' both sides and in one pair (Ta and Tm) in patients' native side. The T2 patients showed less shortening than T1 patients on both the native and the resected sides for Ta and Tm. Conclusion: There were no statistically significant differences in muscle shortening between the controls and the patients, suggesting that patients were unable to adapt to an easier, asymmetric muscle activity as in controls during multiple repetitions of speech task. The effects of palate height and width were independent of the surgical effects. In controls, the muscles functioned synergistically in order to elevate the tongue by decreasing its length and width. In patients, the Ta and Tm worked in concert to decrease tongue width and create a compensatory behavior during tongue elevation. The lesser muscle shortening in T2 than T1 patients suggested greater impairment and limited muscle activity in T2 patients.
    • The Effects of Glossectomy on Anterior and Posterior Motion of the Tongue during Speech

      Reichard, Rachel Elizabeth; Stone, Maureen L. (2012)
      Speech debilitation in patients with glossectomy due to squamous cell carcinoma eradication has been described qualitatively by previous researchers. The purpose of this study was to quantitatively examine the changes in tongue motion in glossectomy patients by comparing them to normal controls to help clarify the effects of the tongue resection/reconstruction on normal motion of the tongue during speech. Eight glossectomy patients, including one with a flap reconstruction, and nine normal controls had MRI recorded in the mid-sagittal plane while uttering "a souk" to evaluate the effects of tumor/resection size, closure procedure used, the level of motor control, and s-type on the velocity and displacement of the tongue tip and body at one or more points in time. No statistically significant differences in tongue motion or motor control were found between normal controls and glossectomy patients, suggesting retention of tongue mobility post-glossectomy. Patients with larger resections were found to have more difficulty with tongue tip motion during speech and one patient treated with flap reconstruction also showed highly altered tongue motion. S-type was not found to have a statistically significant effect on tongue motion. This study suggests that post-glossectomy debility in speech revealed previously most likely cannot be attributed to quantitative changes in tongue motion, but rather qualitative changes in tongue motion.
    • The Effects of Glossectomy on Airway to Tongue Ratio and Mandibular Morphology Using MRI

      Kim, Eric J.; Stone, Maureen L. (2019)
      Purpose: This study asked if glossectomy surgery causes anatomical changes of the surrounding structures and the airway by altering the balance of forces in the oral cavity. We predict that glossectomy patients will have proportionately larger pharyngeal air spaces than controls relative to the hard and soft structures around the mandible. Materials and Methods: Twenty subjects were studied, ten T1 or T2 SCC glossectomies and ten controls. The gathered MRI data sets were reconstructed into 3D volumes. Results: Mid-sagittal transpalatal airway lengths were significantly shorter for the glossectomy subjects. All other measurements were not statistically significant between the two groups. Discussion: A person may compensate for the reduction of tongue size following glossectomy, which may contribute to a shorter A-P airway distance at the transpalatal level. However, all other tests were not statistically significant, including the transpalatal area inidicating that objects in the oral cavity adapt to the reduction in tongue size and does not affect the established equilibrium. The overall transpalatal airway size may be maintained in post-glossectomy speakers by lateral expansion of the airway at the transpalatal level. Conclusion: This study concluded that the spatial relationships between airway and oral structures may change in dimension, but not in balance of forces following glossectomy. Second conclusion was that a 3-dimensional imaging is required for evaluation of the airway.
    • Tongue Asymmetry and Muscle Shortening During Speech in Partial Glossectomy Patients and Controls

      Miller, Natalie; Stone, Maureen L. (2021)
      Tumors of the tongue are routinely removed by partial glossectomy surgery. This study examines the extent of anatomical asymmetries caused by the glossectomy surgery and its effects on the tongue’s resting position and motor symmetry. Magnetic resonance imaging (MRI) data of ten control subjects and ten glossectomy patients were obtained. 3D tongue volumes were extracted from high-resolution MRI data using Matlab. Using cine- and tagged-MRI data, shortening of the genioglossus, transverse, and verticalis muscles were calculated during a speech task involving /∫/ and /l/. Anatomical asymmetries were observed in the control subjects, although they were generally small and less than in glossectomy patients. Glossectomy patients aimed to distribute their tongue volume evenly in the oral cavity, irrespective of anatomical asymmetry, by posturing their tongue towards the resected side. Glossectomy patients shortened more muscles when executing the speech task. Muscle shortening asymmetry was observed in both control and patient groups.
    • Tongue Muscle Shortening Differences in Glossectomy Versus Non-Glossectomy Patients

      Dao, Anh; Stone, Maureen L. (2021)
      In cancers that affect the tongue, the most common treatment is glossectomy, a procedure that can have substantial effects on a patient’s intelligibility. We are seeking to identify the effect of this resection on the use of four muscles – genioglossus, transversus, verticalis, and superior longitudinal, which comprise the bulk of the tongue. MRI data was used to study differences in tongue muscle shortening patterns during the speech task “a thing” between patients who have undergone glossectomies and controls who have not. Speech data was collected from 2D tagged-MRI movies and reconstructed into 3D volumes at 26 timeframes. Velocity fields and tissue points were extracted and shortening was calculated to study how the muscles were used by glossectomies vs. controls to protract and retract the tongue during /θ/. The results reveal differences in function between the two groups, and potential compensation strategies for glossectomy patients.
    • Tongue Position in Glossectomy Patients vs. Controls in /s/ during Speech with consideration for the effects of Palatal Features

      Rezaei Boroun, Atefeh; Stone, Maureen L. (2020)
      Purpose: This study examines the tongue behavior of glossectomy (N = 8) and control (N =12) speakers using a combination of high-resolution and cine- MRI. The speech task “a geese” phonetically spelled /əgis/, was used to measure anterior tongue displacement, termed “anteriority”, for the /ə/, a neutral vowel, and the /s/. Effects on anteriority due to palate height, arch perimeter, inter-canine width and /s/ type were measured on controls and patients. There are two variants of /s/ in English: apical and laminal. The apical /s/ elevates the tongue tip to contact the palate, create a narrow, grooved constriction, and focus the jet stream of air onto the incisors. The laminal /s/ uses the tongue blade, just behind the tip, to create the grooved constriction, and the tip is kept lower in the mouth.[1, 2]