Forehead lines and drooping brows: causes and treatment

Why do forehead lines and drooping brows develop?

Horizontal forehead lines form as the forehead muscle that raises the brows moves again and again, and they deepen with age. A 2014 review explained that wrinkles are created by thinning of the dermis and repeated contraction of the facial muscles beneath it ^[1].

Drooping brows are mainly related to aging. A 2018 review of facial cosmetic surgery in older adults summarized that facial aging stems mainly from the downward descent of the soft tissues and loss of volume ^[2]. When the brows descend, the upper eyelids look heavy, and the habit of tensing the forehead to compensate can make forehead lines even deeper.

Wrinkles that appear only with movement are called dynamic wrinkles, and wrinkles that are visible even when the face is at rest are called static wrinkles ^[1]. This distinction is important in choosing a treatment method.

Wrinkles and sagging are evaluated separately

Forehead lines, drooping brows, and sagging skin on the upper eyelids are intertwined, so it is difficult to judge by looking at just one of them. A 2016 review explained that the brows and upper eyelids should be viewed as a single aesthetic unit, and that an appropriate surgical plan can be made only after understanding the anatomy and the aging process and properly assessing what is in excess and what is lacking around the eyes ^[5].

The same review stressed the importance of identifying any existing asymmetry and drooping of the eyelids (ptosis) before surgery and discussing them in advance, and of talking honestly about the desired result and realistic expectations with the help of standardized photos ^[5]. A review of facial cosmetic surgery in older adults also took the view that a natural result requires evaluating each area separately while also looking at the face as a whole ^[2].

Botulinum toxin injections

Botulinum toxin is a substance that relaxes muscles by blocking the release of acetylcholine where nerves meet muscles ^[1]. When a small amount is injected into specific muscles that move excessively, those muscles relax, the skin above them smooths out, and wrinkles are reduced ^[1].

According to a 2014 review, treatment of frown lines between the brows, crow's feet, and horizontal forehead lines tends to have predictable results, few side effects, and high satisfaction ^[1]. The effect develops fully over about 2 weeks and lasts for 3 to 4 months, and dynamic wrinkles that appear with movement show more noticeable improvement than static wrinkles ^[1]. These data are based on medical practice in the United States.

Mild bruising can occur after injection ^[1]. Rarely, temporary drooping of the eyelid (blepharoptosis) or drooping of the brow can occur; the literature explains that these are complications related to injection technique, so they become less common the more skilled the practitioner is ^[1]. For people whose brows already sit low, the injection points and dose need to be chosen especially carefully.

According to published reviews, injections should be avoided in people with keloid scars, neuromuscular conditions such as myasthenia gravis, an allergy to ingredients of the product, or body dysmorphic disorder ^[1].

Types of brow lift

If the brows droop noticeably, surgery to raise their position is considered. A direct brow lift is a general term for several techniques that use an incision on or around the brow; in the classic method, an oval of skin and the tissue beneath it is removed just inside the brow hairs or directly above the brow ^[4].

This method can be modified to correct only drooping at the outer part of the brow, to place the incision in the middle of the forehead or along the double eyelid crease, or to place the incisions at different heights on each side to achieve symmetry ^[4]. The literature notes that with careful attention to incision placement, stitching technique, and aftercare, the scar may be barely visible in some cases, but this is not a result that applies to everyone ^[4].

An endoscopic brow lift uses an endoscope (a thin camera) to work on the structures beneath the forehead. A 2022 publication explained that controlling the muscles that pull the brows down (depressor muscles) and widely releasing the tissue beneath the membrane covering the bone (subperiosteal dissection) help correct drooping brows, and it also summarized technical pitfalls that can lead to results falling short of expectations ^[3].

Recovery and risks

Injection treatment involves little recovery, but its effect is temporary, lasting about 3 to 4 months, so it needs to be repeated to be maintained ^[1]. Surgery involves an incision, a scar, and a recovery period; it has been summarized that a direct brow lift leaves an incision line around the brow, and that results of the endoscopic method can also vary depending on technical pitfalls ^{[3, 4]}.

When drooping of the upper eyelids and drooping of the brows occur together, correcting only one of them may not produce the desired result. This relates to the point that asymmetry and drooping eyelids should be identified and discussed in advance before surgery ^[5].

The research summaries reviewed here are mainly reviews that describe techniques, so they do not give figures for the rate of complications or how long results last for each type of surgery. Skin thickness, brow shape, and muscle strength differ from person to person, so results also vary between individuals.

What to check during your consultation

Depending on the cause and severity, forehead lines and drooping brows may be adequately treated with injections in some cases, while surgery should be considered in others. It is a good idea to check the following together during your examination.

• Whether your wrinkles appear only with movement or are visible even at rest
• How much your brows droop, how much your eyelids droop, and how much your eyelid skin sags
• How long injection treatment is expected to last and the chance of side effects such as drooping brows
• For surgery, where the incision will be, the scar, and the recovery period
• Whether there is left-right asymmetry, and the result you are hoping for