RESUMEN:
El sistema musculoaponeurótico superficial (SMAS) es una red fibrosa compleja que conecta los músculos faciales a la dermis, con características morfológicas variadas en diferentes regiones faciales. Estudios recientes han identificado cinco tipos distintos de morfología del SMAS, destacando la necesidad de intervenciones específicas en cada región para el rejuvenecimiento facial. Este ensayo iconográfico explora la imagen por ultrasonido del SMAS utilizando transductores de ultra-alta frecuencia (24–33 MHz), conocidos como U-SMAS. El análisis de 186 exámenes de ultrasonido de rostro completo reveló patrones consistentes en las capas faciales y del cuello, con variaciones regionales alineadas con las clasificaciones de Sandulescu: tipo I (preparotideal), tipo II (mentón y labio), tipo III (párpado), tipo IV (temporal y parotideal) y tipo V (cervical). Comprender estas diferencias morfológicas es crucial para una interpretación precisa del ultrasonido y para optimizar evaluaciones pre-procedimiento para tratamientos estéticos seguros y efectivos. El conocimiento de la arquitectura del SMAS mejora la capacidad de visualizar con precisión la anatomía facial y del cuello, especialmente a través de imágenes de ultrasonido, garantizando cuidados integrales al paciente en procedimientos de rejuvenecimiento.

ABSTRACT:
The superficial musculoaponeurotic system (SMAS) is a complex fibrous network connecting facial muscles to the dermis, with varying morphological characteristics across different facial regions. Recent studies have identified five distinct types of SMAS morphology, highlighting the need for region-specific interventions in facial rejuvenation. This pictorial essay explores ultrasound imaging of the SMAS using ultra-high frequency (24–33 MHz) probes, known as U-SMAS. Analysis of 186 full-face U-SMAS scans revealed consistent patterns in the facial and neck layers, with regional variations aligning with the Sandulescu classifications: type I (preparotideal); type II (chin and lip); type III (eyelid); type IV (temporal and parotideal); and type V (cervical). Understanding these morphological differences is crucial for accurate interpretation of ultrasound images and for optimizing pre-procedural assessments to ensure that aesthetic treatments are safe and effective. Knowledge of the SMAS architecture enhances the ability to visualize facial and neck anatomy accurately, particularly through U-SMAS imaging, ensuring comprehensive patient care in rejuvenation procedures.

ABSTRACT:
The superficial musculoaponeurotic system (SMAS) is a complex fibrous network connecting facial muscles to the dermis, with varying morphological characteristics across different facial regions. Recent studies have identified five distinct types of SMAS morphology, highlighting the need for region-specific interventions in facial rejuvenation. This pictorial essay explores ultrasound imaging of the SMAS using ultra-high frequency (24–33 MHz) probes, known as U-SMAS. Analysis of 186 full-face U-SMAS scans revealed consistent patterns in the facial and neck layers, with regional variations aligning with the Sandulescu classifications: type I (preparotideal); type II (chin and lip); type III (eyelid); type IV (temporal and parotideal); and type V (cervical). Understanding these morphological differences is crucial for accurate interpretation of ultrasound images and for optimizing pre-procedural assessments to ensure that aesthetic treatments are safe and effective. Knowledge of the SMAS architecture enhances the ability to visualize facial and neck anatomy accurately, particularly through U-SMAS imaging, ensuring comprehensive patient care in rejuvenation procedures.