Objectives-Tongue volume reduction is an adjunct treatment with several orofacial orthopedic procedures for various craniofacial deformities; it may affect structural reconstitution and functional recovery as a result of the repair process. The aim of this study was to investigate the myogenic regeneration and structural alteration of the tongue following surgical tongue volume reduction.Materials and Methods-Five 12-week-old sibling pairs of Yucatan minipigs (3 males and 2 females) were used. Midline uniform glossectomy was performed on one of each pairs (reduction); the other had the same incisions without tissue removal (sham). All pigs were raised for 4 weeks, and received 5-bromo-2-deoxyuridine (BrdU) injection intravenously one day before euthanasia. Tissue sections of tongues were stained with anti-BrdU antibody to evaluate the number of replicating cells. H&E and Trichrome stains were applied to assess muscular structure.Results-Reduction tongues contained significantly more BrdU+ cells as compared to sham tongues (p < 0.01). However, these BrdU+ cells were mostly identified in the reparative connective tissues (fibroblasts) rather than the regenerated muscle tissues (myoblasts). Trichrome stained sections showed disorganized collagen fibers linking with a few intermittent muscle fibers in the reduction tongues. These myofibers presented the signs of atrophy with reduced perimysium and endomysium. The matrix between these reduced perimysium and endomysium was fully filled with fibrous tissue.Conclusions-Fibrosis without predominant myogenic regeneration is the major histologic consequence after surgical tongue volume reduction.

A healed volume-reduced tongue may change loading regime significantly by elevating loading and altering strain-dominant pattern and orientation on its surrounding structures, and these changes are more remarkable in mandibular than maxillary sites.