Welcome to this month's journal review, covering Dermatologic Surgery for December 2025. This is a lighter issue for us in terms of volume — we're covering a single article — but it's a good one, so we'll spend our time doing it justice. It comes from the Reconstructive Conundrum series, and it's a case-based technique piece walking through repair of a wide mental defect. Let's get into it.

This is structured as a reconstructive conundrum, which for those who don't read this section regularly, is essentially a case-based teaching format — a defect is presented, the anatomic and reconstructive considerations are walked through as if you were standing at the table trying to decide, and then the chosen solution is revealed with the technical detail needed to replicate it. There's no methods section, no results, no limitations discussion in the traditional sense — this is pure operative reasoning and pearls, so I'll walk through it the way the authors do.

The case is an 82-year-old woman with a recurrent, infiltrative basal cell carcinoma of the mentum. It took four stages of Mohs to clear, and what she was left with was a substantial defect — 6.2 by 2.6 centimeters, involving more than half of the mentum subunit. A few things made this particular defect tricky beyond just its size. First, the underlying mentalis and depressor labii inferioris muscles were intact, which is good news structurally, but the defect sat close to the free margin of the lower lip, and the mentum itself is a convex surface, both of which raise the stakes for any tension-based closure pulling on that lip. Second — and this is the detail that really shapes the whole case — she had prior surgery in the area, with hypopigmented atrophic scarring and an existing leftward pull on her lower lip. So there was already baseline contracture working against them before a single suture was placed.

The authors talk through why the more obvious options don't work well here. Second-intention healing or a primary linear closure were off the table given the sheer size and width of the defect. A full-thickness skin graft was technically feasible, but they anticipated a poor color, texture, and thickness match on the chin — a common problem with grafts in this location. An advancement flap design — something like an inverted O-to-T, an O-to-L, or a bilateral O-to-H — was considered, but the existing contracture at her left oral commissure limited how far that tissue could move and raised real risk of flap failure and, critically, eclabium — ectropion of the lip. A bilobed transposition flap recruiting from the neck was also floated but rejected because it would likely leave conspicuous, unnatural lines and still carry eclabium risk.

What they landed on was two inferiorly based rotation flaps, each one advancing superiorly and rotating centripetally into the defect, drawing tissue from the mandibular chin bilaterally, the submentum, and the neck. The logic here is worth sitting with because it's the generalizable teaching point of the whole piece. Using two flaps instead of one lets them recruit tissue from reservoirs on both sides plus the submentum, rather than relying on a single reservoir to stretch further than it wants to. And critically, when you combine two rotation flaps designed with a shared upward vector, the net movement of tissue lifts the reconstruction rather than dragging it down — which directly counteracts the eclabium risk that sank the other options.

On the technical design: each crescentic flap was drawn with a length-to-width ratio of about two to one, and the arc of rotation for each flap was kept at ninety degrees or less — both classic rotation-flap biomechanics principles to keep closure tension low and minimize standing cone size. The incision lines and the standing tissue cones were deliberately placed along the labiomental crease superiorly and the labiomandibular grooves laterally — in other words, hidden along the natural cosmetic subunit borders of the mentum. Undermining was carried out above the muscular plane specifically to protect the mental nerve branches, which dive deep into the musculature after exiting the mental foramen, and to protect the labiomental and submental arteries, which travel in the fascial and subfascial planes. Key sutures were placed to lock the flaps laterally, reduce distortion, and — again — actively lift the flaps upward to help them resist gravitational descent as the scars mature and contract. Closure was standard layered technique, buried poliglecaprone-25 and a running nylon epidermal layer.

There's no formal outcomes data here, obviously — it's an n-of-one case report — but for what it's worth, the patient healed without complication, and at follow-up she had an excellent cosmetic result. The only residual issue was some telangiectasia, for which she was offered vascular laser and declined, stating she was satisfied with the outcome as is.

So what do you actually take from this. This isn't a practice-changing paper in the sense of shifting how you think about margins or recurrence risk — it's a technique pearl, and the way to use it is as a reconstructive option to have in your back pocket specifically for wide mentum defects, especially in the setting of a hostile local environment — prior surgery, existing contracture, or lip tightness — where your usual advancement or transposition options are compromised. The generalizable principle worth carrying forward, even outside this exact defect, is the idea of deliberately combining two flaps with vectors that sum to a net upward pull whenever you're reconstructing near a free margin prone to ectropion or eclabium — lower lid, lower lip, alar rim. That vector-summation logic is the real transferable lesson here, more than the specific flap geometry itself.

That wraps up this month's review. A short one, but a genuinely useful addition to the chin and lower-face reconstructive toolkit. Thanks for listening, and I'll see you next month.