Acne Scar Types and Approach
Decided by Shape and Depth

Three-Line Summary

• Acne scars divide into ice pick, rolling, and boxcar morphologies, and a real face usually carries a mixture. Each type calls for different modalities.
• Breaking scars into the scar wall, the dermal deficit, and subcutaneous tethering is the framework that determines results. A three-layer combination is often more effective than repeating a single device.
• Sessions and time are required, and complete flattening is not the goal — making scars less noticeable is. Coexisting active acne and PIH risk are managed through sequence and parameters.

Three Types of Acne Scars — Morphological Definitions

Before treating, we classify by shape. The internationally accepted classification has three categories.

Ice pick

A narrow, deeply punched-out type with a small surface opening that extends down into the dermis, with the narrow, angular cross-section of a puncture. Because of that depth, superficial remodeling alone rarely improves it.

Rolling

A type with gently undulating borders. The surface is not angular, but the defining feature is fibrous tethering that binds the scar to tissue below and pulls it down. Unless that tethering is released, surface remodeling alone produces little change.

Boxcar

A type with sharply defined, angular borders, subdivided into shallow and deep. Because the scar wall is distinct, the approach must reshape that wall. Boxcar scars are wider than ice pick scars and more sharply demarcated than rolling scars.

In practice these three types coexist, and the dominant type can differ by facial area. In consultation we separate types area by area and design the approach accordingly.

The Three-Layer Framework — Scar Wall, Dermal Deficit, Tethering

Independently of scar type, the working framework breaks the problem into three layers.

• Scar wall (surface wall) — the surface layer forming the scar border. The approach reshapes this wall so the border softens.
• Dermal deficit — the layer where dermis beneath the scar has thinned or been lost. The approach induces collagen reorganization to fill that deficit.
• Subcutaneous tethering — the layer where the scar is bound to deeper tissue. This bond must be released physically before the surface can rise.

Each layer has its own corresponding modality. The combination depends on which layer carries the largest share, and when all three contribute, a sequenced combination is natural.

Four Modalities and the Layer Each Addresses

Potenza RF microneedling — dermal remodeling

Potenza delivers radiofrequency energy from the tips of microneedles. The needles pass through the epidermis to create precise points at dermal depth, where RF drives dermal remodeling.

Its primary layer is the dermal deficit, with some effect on the scar wall. Because epidermal injury is limited and recovery relatively short, it is often the baseline modality when several scar morphologies are mixed.

Fractional CO2 laser — reshaping the scar wall

Fractional CO2 creates columns of microthermal injury from epidermis into dermis, triggering wound healing and re-epithelialization around each column. Its strength lies in reshaping the scar wall.

It suits sharply demarcated scars such as boxcar, softening the border. Because there is epidermal injury, recovery time and sun protection matter more than with Potenza.

Subcision — releasing tethering

Subcision physically divides the fibrous bands beneath a scar with a fine needle, releasing the downward pull. It is particularly effective for rolling scars, and scars that would not rise with surface remodeling often lift naturally once tethering is released.

Trifill and hyaluronidase — reinforcing or adjusting the release

After subcision, filler (such as Trifill) can be placed into the space beneath the scar so the surface does not settle again; conversely, where residual filler is itself the source of tethering, hyaluronidase releases it. These are combined when subcision alone is insufficient.

What We Actually Assess in Consultation

These items are reviewed when planning scar treatment. Their combination is settled before any modality is chosen.

• Scar morphology — the distribution of ice pick, rolling and boxcar scars, area by area.
• Scar depth — whether scars are superficial or extend into deep dermis changes session count and intensity.
• Presence of tethering — stretching the skin around a scar shows whether it lifts. Where tethering exists, subcision carries a larger share.
• Coexisting active inflammatory acne — active acne requires adjusting the order of scar treatment.
• Fitzpatrick skin type and PIH history — darker skin tones or a history of PIH change parameters and session intervals.
• Prior procedure history — previous scar treatments or filler in place alter the combination.
• Downtime tolerance — fractional CO2 involves erythema and crusting, which must fit the patient's schedule.

How a Session Actually Proceeds

Scar treatment repeats across sessions, but each session follows the same sequence.

• Consultation and classification — scar types and dominant layers are recorded by area, and per-session goals are designed together.
• Photography and marking — scar locations and types are photographed and the treatment area marked.
• Anesthesia — topical anesthetic with absorption time; local anesthetic injection is added when subcision is combined.
• Treatment — the modalities matched to each type (Potenza, fractional CO2, subcision, Trifill) are performed in the required order.
• Soothing and aftercare preparation — heat and erythema are reduced and recovery guidance given.
• Session planning — the next interval and the areas and modality combination to address are planned in advance.

Indications and Contraindications

Indications

• Atrophic scars remaining after acne (ice pick, rolling, boxcar)
• Mixed scars combining different depths and shapes
• Scars where improvement has plateaued with surface remodeling because of tethering
• Boxcar scars with distinct walls requiring border softening

Contraindications or Cautions

• Pregnancy or breastfeeding
• Active infection or open wounds in the treatment area
• Active inflammatory acne — the principle is to stabilize acne before starting.
• Keloid or hypertrophic scarring tendency — the response can be the opposite of that in atrophic scars, so parameters require particular caution.
• Darker skin tones (Fitzpatrick IV–VI) — relatively higher PIH risk; early sessions start at lower intensity while the response is observed.
• Recent oral isotretinoin — an interval is generally recommended.
• Periods of heightened photosensitivity — recovery is harder to manage right after strong summer sun exposure, so timing is adjusted.

Because contraindications include both absolute and relative cases, sharing your history, medications and prior procedures accurately in consultation allows a safe plan.

The Limits of Scar Treatment — Complete Flattening Is Not the Goal

Acne scar treatment takes sessions and time, and the following set a realistic ceiling on results.

• Complete flattening is difficult — the structural deficit does not disappear; the goal is to make scars less noticeable. Residual contour may still show under certain lighting and angles.
• Sessions and time are required — this is not a one- or two-session transformation but an accumulation of tissue response over multiple sessions.
• Very deep ice pick scars exceed surface remodeling — these may require punch excision or punch elevation, and we explain in advance that some scars cannot be managed by energy devices alone.
• PIH and pigment outcomes depend heavily on aftercare — independent of the procedure itself, post-treatment sun and irritation management shape the final impression.

Scar treatment is a tool for making scars less visible, not for erasing them. Keeping this distinction clear is what prevents disappointment mid-course.

How ABLE Dermatology Approaches It

Three principles guide our scar consultations.

• Separate type and layer first — record scar type and dominant layer (wall, deficit, tethering) by area, then match modalities.
• A three-layer combination often beats repeating one device — when CO2 alone is repeated on tethered scars and progress stalls, the sequence needs subcision first.
• State the goal up front — plan sessions, intervals and cost around improvement rather than complete flattening.

Rather than a single procedure, we suggest confirming in consultation the sequenced combination suited to your scar types and layer composition.

Key Points

Acne scars divide into ice pick, rolling and boxcar types, and in practice are best addressed by decomposing them into the three-layer framework — scar wall, dermal deficit, subcutaneous tethering — and combining the matching modalities (Potenza, fractional CO2, subcision, Trifill). Sessions and time are required, improvement rather than complete flattening is the realistic goal, and active acne and PIH risk are managed through sequence and parameters.