The stimulation of the genioglossus muscle may prevent upper airway collapse in breathing disorders such as obstructive sleep apnea (OSA). Thus, the present study was to analyze the 3D-changes of the tongue base by electric stimulation of genioglossal muscle in relation to volumetric alterations of the tongue base in minipigs. Twenty 8-to-9-month-old Yucatan minipigs were used. Of them, 8 were controls, and 12 were experimental. Each experimental same-sex sibling pair was randomly assigned: 1. Normal-weight having surgical tongue base volumetric reduction. 2. Enlargement having significant obesity, BMI>50. All minipigs received surgical implantation of eight 2mm ultrasonic crystals in a cubic-shaped array in the tongue base. The distance change between each crystal pair indicated dimensional deformations for lengths, widths, and thicknesses responding to the stimulation. Increased distances indicated elongations while decreased indicated shortenings. Stimulations to the left genioglossal muscle were ramping up in range of 10-40V to reach the maximal amplitudes (tetany). Stimulation of the genioglossus muscle in controls induced left lengthening, anterior thickening and overall widening along with posterior thinning and right shortening. In contrast, the reduction group showed thickening and widening with left lengthening and minor right shortening. Elongations in the reduction group were larger than those in the control group (p<0.05). The enlargement group showed decreased dorso-ventral lengths compared to those of the control and reduction groups (p<0.05), along with antero-posterior thickening and widening. Stimulation of the genioglossus muscle induces distinctive deformational patterns between the normal and volumetric-altered tongue bases. For instance, shortening in length in the enlarged tongue due to obesity may suggest retraction of the tongue base inducing narrowing of the oropharyngeal airway. These results may contribute to understanding kinematic adaptations in the respiratory dynamics in relation to the volumetric alterations of the tongue base, a current approach to treat moderate and severe OSA. 

The aim of this study was to examine the respiratory 3D deformational changes in the tongue base with normal weight and obesity in a minipig model. This study included 6 same-sex sibling pairs (3 pairs each sex) of Yucatan minipigs 8-to-9 months old. Of each pair, one minipig was normal weight with a BMI<35 and the other was fed a special diet reaching a BMI>50 (obese,). While under sedation, eight 2mm ultrasonic piezoelectric crystals with an extended skin button attached to the back were surgically implanted at the base of the tongue in a cubic-shaped arrangement. These crystals represented dorsoventral lengths, anteroposterior widths, and thicknesses. The 3D deformational changes of the tongue base were recorded during respiration using a Sonometric system together with synchronized electromyography and airflow recordings to identify respiratory phases. The amplitudes and durations of each dimensional change within the crystal-defined region concerning inspiration were calculated for 5- consecutive respiratory cycles per minipig. The total respiratory cycle duration was 1.87±0.38s in the normal-weight group and 3.2±1.01s in the obese group (p<0.05).  Similarly, the durations of the inspiratory phase in the normal and obese groups were 0.62±0.36s and 1.19±0.77s respectively (p<0.05). Deformational changes in the normal-weighted group included dorsoventral lengthening, anteroposterior ventral widening with dorsal shortening, and thickening in all dimensions. In contrast, the obese group showed dorsal lengthening with ventral shortening, widening in all dimensions, and anterior thickening with posterior shortening. Overall, larger dynamics were observed in the normal-weighted group compared to the obese group (p<0.05). These results demonstrate that obesity affects tongue base respiratory kinematics, with longer respiratory cycles and decreased deformational changes mainly ventrally and posteriorly. These findings enhance understanding of obesity's impact on the oropharyngeal function, with implications for breathing disorders.

The purpose of this research is to examine myoregeneration and tissue effects on the tongue base following surgical injury and adipose tissue accumulation in minipigs. Twenty, 8-9 months old Yucatan minipigs were studied. Eight minipigs were assigned as the control group, and other 6 same-sex pairs were used as intervention groups. In each pair, one was intentionally fed to obesity (BMI>50) and the other one with normal weight (BMI < 35) received surgical ablation of the tongue base. BrdU was administered intravenously to track muscular cell proliferation and myofiber formation, with injections given 15 days and 2 days before the termination, respectively. Tongue base samples were paraffin-embedded and cut into 7µ sections for routine H&E, Trichrome, and immunohistochemical staining. Quantitative cell counts and semi-quantitative analysis of labeled cell density and differentiation were performed using the grid system and coding approach to examine muscular responses to the injury and adipose tissue infiltration. The anticipated result will be: 1) fewer muscle satellite cells in the control group; 2) increased adipose cells occupying the spaces between myofiber; 3) significantly more active myoregeneration, with a higher presence of satellite cells in the surgical group. The outcome of this study will elucidate the potential capacity of the tongue base to respond to wound injury and adipose tissue infiltration.