What is bone tunnel fixation in a forehead lift?
A forehead lift releases sagging forehead and brow tissues, repositions them in an appropriate direction, and secures them at a new position.
Several fixation methods can maintain the repositioned tissues; bone tunnel fixation is one of them.
Bone tunnel fixation involves creating small tunnels in the outer cortical bone of the skull, just large enough to pass sutures through, and using those sutures to secure forehead and scalp tissues to the bone.
The bone provides a firm anchor, while tunnel placement, suture direction, and tension can be adjusted to the direction of brow descent and differences between the two sides.
Bone tunnel fixation has long been used in endoscopic forehead lifts. UVOM Plastic Surgery also uses it according to the patient's condition and surgical plan.
However, it is not applied identically to every patient.
Tunnel placement and fixation methods may vary with the condition of the tissues, including the scalp and periosteum, bone thickness and shape, and adhesions from previous surgery.
The durability of a forehead lift also depends on the extent of dissection, tissue movement, suture placement, tension, and postoperative tissue reattachment and healing, rather than the bone tunnel alone.
Why UVOM uses bone tunnel fixation
① No separate plate-type fixation device is used
Bone tunnel fixation uses bone and sutures to secure tissue without inserting a separate plate-type fixation device such as Endotine.
It may therefore be considered for patients concerned about an additional fixation device or about feeling a prominence or palpable device.
However, not using a plate-type device does not mean that all discomfort is avoided.
Bone tunnel fixation also uses sutures, and temporary firmness, pulling sensations, tenderness, or sensory changes can occur after surgery.
Nor does avoiding a fixation device necessarily make an approach safer or superior.
Each fixation method has advantages and limitations. The choice should reflect the forehead and brow condition, skin and tissue thickness, and the surgeon's technique.
② Fixation points and directions can be planned for the individual patient
The eyebrows are not structures that simply need to be lifted straight upward.
Some patients have pronounced descent of the brow tails, while others also have descent of the inner brows,
and some have differences in brow height or frontalis muscle use between the two sides.
Rather than pulling every patient's brows from the same points in the same direction,
the pattern of descent should be assessed to plan the required direction of lift.
Bone tunnel fixation allows the following factors to be adjusted to the patient's condition.
- Location of the bone tunnels
- Location of the tissue engaged by sutures
- Direction of tissue traction
- Fixation tension on each side
- Degree of lift in the inner and outer brows
For example, when lateral brow descent is more severe, lateral fixation may need greater consideration,
whereas descent involving the inner brows also requires assessment of central and medial movement.
This does not mean bone tunnel fixation is the only method that allows these adjustments.
Other fixation methods also allow placement and direction to be planned for the patient,
and bone tunnel fixation is one method in which the tunnel locations and suture directions can be set directly.
③ It is a long-established fixation method
Bone tunnel fixation has long been used in endoscopic forehead lifts.
Being an established method does not mean that it is no longer used,
and even with newer fixation methods available, it remains an option according to the surgeon's technique and the patient's condition.
Bone tunnel fixation uses bone as an anchor without a separate plate-type device,
and allows suture direction and tension to be adjusted to brow position and side-to-side differences observed during surgery.
A forehead lift involves more than simply pulling sagging skin upward.
Adequately released forehead and brow tissues must be able to move without excessive strain and remain stable in a position suited to facial proportions and brow shape.
Alongside the fixation method, it matters whether the tissue has been adequately dissected in the appropriate plane,
in which direction it is moved, and where it is secured.
Bone tunnel fixation is one of several methods used in keeping with these surgical principles.
Why surgical planning and technique matter in bone tunnel fixation
In bone tunnel fixation, the surgeon directly plans tunnel location and angle, the tissue engaged by sutures, the direction of fixation, and tension.
Using the same method does not mean creating tunnels at identical points and applying the same traction in every patient.
The location and direction of brow descent, brow heights, frontalis use, and mobility of the skin and scalp differ between patients.
One patient may have descent of the entire brow, while another has more pronounced descent at the brow tail.
One brow may naturally be higher or lower, or habitual use of one side of the frontalis may contribute to a height difference.
Before surgery, the following should therefore be assessed in addition to the degree of brow descent.
- Brow height on each side
- Degree of inner and outer brow descent
- Distance between the eyes and brows
- Forehead length and facial proportions
- Degree of frontalis muscle use
- Actual brow position with the forehead relaxed
- Differences in muscle use between the two sides
- Previous surgery and possible adhesions
- Condition of scalp and periosteal tissues
Based on this assessment, the surgeon determines where to create bone tunnels and which tissues to engage with sutures,
as well as the direction of movement and the tension used for fixation.
Decisions made by the surgical team
Why they matter
Bone tunnel location
The required direction of brow elevation must be considered
Extent of dissection
Tissues must be able to move upward without excessive strain
Suture placement
A position that securely holds the repositioned tissues must be selected
Direction of traction
The direction varies with the pattern of brow descent
Tension on each side
Pre-existing brow asymmetry and differences in muscle use
must be considered
Final fixation position
Excessive elevation and an unnatural brow shape should be avoided
However, pre-existing side-to-side differences in the skeleton, muscles, and eyelids are difficult to eliminate completely.
Postoperative swelling and tissue healing may also differ between sides, so perfect symmetry cannot be guaranteed by surgery.
Considerations for bone tunnel fixation in revision surgery
A different approach may be needed after previous forehead or brow lift surgery.
Revision patients may have adhesions, scar tissue, altered dissection planes, or remaining fixation devices or sutures from the previous operation.
Before revision surgery, the following should therefore be assessed alongside current brow position.
- Previous incision locations
- Previous fixation method
- Brow height and shape on each side
- Possible tissue adhesions
- Changes in scalp sensation
- Degree of frontalis muscle use
- Distance between the eyes and brows
- Persistent pulling sensations or discomfort after the previous operation
- Desired direction of improvement
In revision surgery, tissues may already have undergone dissection and fixation,
making identification of tissue planes and release of adhesions potentially more important than in the first operation.
Bone tunnel fixation is not suitable for every revision patient,
and another fixation method or a staged surgical plan may be needed depending on tissue condition and the previous technique.
Does greater brow elevation mean better bone tunnel fixation?
No.
The goal of a forehead lift is not to raise the brows as high as possible,
but to improve the heavy appearance caused by brow descent while repositioning tissues in harmony with facial proportions.
Natural brow height and shape, eye-to-brow distance, forehead length, face shape, and asymmetry vary between individuals.
The same amount of elevation may therefore look natural in one person and excessive in another.
In a patient with pronounced lateral brow descent, lifting the inner and outer brows equally may over-elevate the entire brow and create a surprised appearance.
Conversely, lifting only the brow tails in a patient with inner brow descent may not sufficiently improve central heaviness.
For bone tunnel fixation, preoperative assessment of brow position and movement should guide the direction and degree of lift needed.
- Assessing brow height on each side
Human eyebrows are not naturally perfectly symmetrical.
Some people use one side of the frontalis more, and some naturally have one brow slightly higher or lower.
Fixing both sides at the same position and tension without assessing these differences does not necessarily produce symmetry.
Ignoring existing asymmetry and tissue movement may make side-to-side differences more apparent after surgery.
Pre-existing brow asymmetry and the direction of tissue movement should therefore be assessed before planning fixation position and tension separately for each side.
Because all pre-existing skeletal and muscular asymmetry is difficult to eliminate,
the approach should seek balance while accounting for existing differences as fully as possible, rather than aiming for perfect symmetry.
- Assessing frontalis muscle use
Patients with substantial brow descent may unconsciously contract the forehead to lift their brows.
Assessing brow position during this compensatory frontalis activity may make the brows appear higher than their true resting position.
Before surgery, it is important to check how far the brows descend when the forehead is relaxed,
whether both sides of the frontalis are used equally, and whether one side contracts more strongly.
If habitual frontalis use is not adequately considered when planning elevation, the brows may feel higher or lower than expected after surgery.
Both a neutral expression and forehead contraction should be assessed preoperatively to evaluate actual brow position and movement comprehensively.
What determines the strength of bone tunnel fixation?
Because bone tunnel fixation uses the outer cortical bone of the skull as an anchor, relatively firm initial fixation can be expected.
However, the long-term durability of a forehead lift is not determined by the bone tunnel alone.
Stable reattachment of tissue in the new position is important, and the following factors also play a role.
- Appropriate dissection plane
- Adequate extent of dissection
- Tissue movement without excessive strain
- Anchor point location
- Strength of the tissue engaged by sutures
- Suture direction and tension
- Patient's skin and soft tissue condition
- Postoperative swelling and healing response
- Scar tissue formation
- Individual aging and tissue relaxation
Use of bone tunnel fixation alone does not establish the outcome or its durability.
Even with the same fixation method, outcomes may vary with tissue condition, dissection extent, fixation position, and postoperative recovery.
Differences between bone tunnel fixation and Endotine
Bone tunnel fixation and Endotine are both used to secure repositioned tissues in a forehead lift.
The main difference is the structure used for fixation.
Category
Bone tunnel fixation
Endotine
Fixation method
Small bone tunnels and sutures secure the tissue
An absorbable plate-type fixation device secures the tissue
Separate fixation device
No plate-type fixation device
An absorbable fixation device is used
Position adjustment
Bone tunnel locations and suture directions are planned directly
Device position and the area of tissue fixation are planned
Potential palpability
Firmness or discomfort may occur at suture sites
The device may be palpable or feel prominent early on
Selection criteria
Tissue condition, bone shape, and surgical technique
are considered
Skin and tissue condition, required fixation area, and surgical
technique are considered
It is difficult to conclude that one method is superior for every patient.
Bone tunnel fixation uses bone and sutures, whereas Endotine uses an absorbable fixation device.
The appropriate method can be selected according to forehead and brow condition, skin and tissue thickness, bone shape, previous surgery, and the surgeon's technique.
In some cases, more than one fixation method may be combined.
Frequently asked questions (FAQ)
Q. Does bone tunnel fixation create large holes in the skull?
A. No. It generally involves small tunnels in the outer cortical bone of the skull, just large enough for sutures to pass through.
It does not involve removing a large amount of bone or creating a large hole through the full thickness of the skull.
Nevertheless, because tunnels are created in bone, their location, angle, and depth must be planned accurately.
Q. Is drilling into the skull dangerous?
A. Bone tunnel fixation has long been used to create small tunnels in the outer cortical bone of the skull.
Although it is generally performed within safe anatomical limits, tunnel location, angle, and depth must be precisely controlled.
In particular, tunnels must remain within the safe limits of the outer cortical bone to avoid entering structures inside the skull.
The surrounding bone may undergo healing after surgery, but healing patterns vary between individuals.
Q. Is fixation weaker without a fixation device?
A. Not necessarily.
Bone tunnel fixation uses the outer cortical bone of the skull as an anchor and sutures to hold forehead and scalp tissues in place.
The absence of a separate plate-type device therefore does not necessarily mean weaker fixation.
However, the durability of a forehead lift does not depend on bone tunnel fixation alone.
Dissection extent, tissue movement, suture placement and tension, tissue reattachment, and individual healing responses all contribute.
Q. Can bone tunnel fixation be used for asymmetrical brows?
A. Yes.
When brow heights or directions of descent differ, rather than pulling both sides identically,
it is important to adjust fixation position, suture direction, and tension to each side's condition.
Brow asymmetry may reflect several factors, including the skeleton, frontalis use, and eyelid condition, as well as skin and soft tissue.
Bone tunnel fixation does not eliminate all asymmetry completely. Pre-existing side-to-side differences and the extent of achievable correction should be carefully assessed.
Q. Which is better: bone tunnel fixation or Endotine?
A. No single method can be said to be better for every patient.
Bone tunnel fixation secures tissue with bone and sutures,
whereas Endotine uses a separate absorbable fixation device.
Bone tunnel fixation does not require a plate-type device,
while Endotine can support tissue over a relatively broad area.
The actual choice depends on forehead and brow condition, skin and tissue thickness, bone shape, previous surgery, and the surgeon's technique.
Rather than judging outcomes by the name of a fixation method alone, it is important to check that dissection is adequate and fixation is planned accurately.
Q. Does the surgeon's experience matter for bone tunnel fixation?
A. Yes.
The surgeon must directly plan tunnel location, angle, and depth, the tissue engaged by sutures, the direction of traction, and tension on each side.
This requires understanding the anatomy of the skull, forehead, and brow region and incorporating the direction of brow descent and degree of frontalis use into the plan.
Strong traction without sufficient release can create excessive tension or an unnatural brow shape, so dissection, movement, and fixation must be balanced.
In revision surgery, adhesions and existing fixation also need assessment, making preoperative diagnosis and planning potentially even more important.
For further questions about forehead lifts and bone tunnel fixation, contact UVOM Plastic Surgery at 02-545-3700 or
via KakaoTalk at 'UVOM Plastic Surgery' for a consultation to assess your forehead and brows accurately.
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