# Age-related changes in platysma insertion height and the clinical role of high-resolution ultrasound in the elderly

## TL;DR

This study explores how aging affects the platysma muscle's position and validates high-resolution ultrasound as a tool for assessing it in elderly patients.

## Contribution

The study provides the first quantification of age-related changes in platysma insertion height and validates high-resolution ultrasound for its assessment.

## Key findings

- The platysma insertion height was found to decrease with age by 0.54 mm per year.
- High-resolution ultrasound reliably identifies the platysma in the neck but underestimates cranial insertion height in the face.
- The platysma often extends into the midface, but this becomes less discernible with age.

## Abstract

There is no consensus on the exact insertion height of the platysma muscle, and the influence of aging on its cranial position remains unexplored. Additionally, clinicians currently rely solely on clinical examination to assess the muscle—a limitation that may contribute to complications when treating platysma synkinesis with botulinum toxin injections. This study aimed to determine the cranial insertion height of the platysma in an elderly cohort, explore how aging affects its cranial position, and validate high-resolution ultrasound as a non-invasive tool for visualizing and assessing the muscle in the neck and face.

Thirty-eight hemifaces were studied in body donors of advanced age (mean: 83.5±8.7). Using high-resolution 22 MHz ultrasound, the platysma muscle was assessed in the neck, and the cranial insertion height was established within a coordinate system and verified through anatomical dissection. The effect of age on insertion height was analyzed using linear mixed-effects models.

The cranial platysma insertion height was found 2.9 ± 1.0 cm above the mandibular angle. Increasing age was associated with a decrease in insertion height by 0.54 mm per year (p<0.05). Ultrasound successfully identified the platysma in the neck in 34 of the 38 hemifaces but underestimated the cranial insertion height by 0.84 cm (mean).

The platysma muscle often extended into the midface, but increasing age was associated with a reduction in its discernible insertion height. High-resolution 22 MHz ultrasonography of the platysma can reliably assess the platysma and guide treatment in the neck in elderly patients but underestimates the cranial insertion height in the face.