RESUMEN
BACKGROUND: This study is to evaluate and compare the improvement of upper airway morphology and hyoid bone position in children with Class II mandibular retrusion treated with Invisalign mandibular advancement (MA) and Twin-Block (TB) appliances, utilizing cone beam computed tomography (CBCT). METHODS: 32 children aged between 8 and 11.5 years old were included in this study, with an average age of 10.2 years old. These children were divided into two groups, MA and TB, with 16 children in each group. Changes in upper airway morphology and hyoid bone position before and after treatment were analyzed using CBCT. RESULTS: (1) Changes in upper airway before and after treatment: the oropharynx volume (Or-V), the oropharynx minimum cross-sectional area (Or-mCSA), the hypopharynx volume (Hy-V), and the hypopharynx minimum cross-sectional area (Hy-mCSA) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05) compared to pre-treatment status. (2) Changes in hyoid bone position before and after treatment: The distances between H point and third cervical vertebra (H-C3), H point and pogonion (H-RGN), H point and mandibular plane (H-MP), H point and Frankfort horizontal plane (H-FH), H and S point (H-S), and H point and palatal plane (H-PP) in both the MA and TB groups increased after treatment, and the differences were statistically significant (P < 0.05). CONCLUSION: Both MA and TB appliances effectively improved the structural narrowness of the upper airway and reduced respiratory resistance, thus improving breath quality. However, MA showed more effectiveness in improving the narrowest part of the hypopharynx compared to TB. Both appliances also promoted anterior downward movement of the hyoid bone, which opens the upper airway of the oropharynx and hypopharynx and helps the upper airway morphology return to normal range.
Asunto(s)
Avance Mandibular , Aparatos Ortodóncicos Removibles , Niño , Humanos , Estudios Retrospectivos , Hueso Hioides/diagnóstico por imagen , NarizRESUMEN
Inflammationrelated bone defects pose a heavy burden on patients and orthopedic surgeons. Although stemcellbased bone repair has developed rapidly, it is of great significance to characterize bioactive molecules that facilitate bone regeneration. It is reported that a glucagonlike peptide 1 receptor agonist, exendin4, promoted bone regeneration mediated by the transplantation of adiposederived stem cells in a metaphyseal defect mouse model of femur injury. However, the underlying mechanism is unclear. Bone imaging, immunohistochemistry realtime PCR and western blot analysis were used in the present study, and the results revealed that exendin4 increased the transcription of the osteogenic differentiationrelated genes and induced osteogenic differentiation in situ. Furthermore, the present data obtained from sorted adiposederived stem cells revealed that exendin4 promoted osteogenic differentiation and inhibited adipogenic differentiation in vitro. These findings indicated that exendin4 facilitates osteogenic differentiation of transplanted adiposederived stem cells for bone repair and illuminated clinical prospects of both adiposederived stem cells and exendin4 in stemcellbased bone defect repair.