**Region:** Head and Neck # Temporalis Muscle Flap ## Anatomy - Pedicle: - Deep temporal arteries (typically two main branches: anterior and posterior) arising from the pterygoid (intratemporal) portion of the internal maxillary artery; venae comitantes accompany the arteries. The deep temporal arteries enter the deep (medial) surface of the temporalis muscle just above its coronoid insertion. (Hanson; Panossian) - Accessory supply: middle temporal artery (branch of the superficial temporal artery) supplies the deep temporal fascia and may be sacrificed for muscle transfer; communicates with deep temporal system. (Hanson) - Course: the deep temporal arteries run on the deep surface of the muscle after branching from the internal maxillary system and provide longitudinal intramuscular branches supplying the fan-shaped muscle from medial to lateral. (Hanson; Panossian) - Perforator pattern: muscle is supplied by intramuscular branches; the temporalis behaves as a Mathes & Nahai type III muscle (dual vascular pedicles — anterior and posterior deep temporal arteries). Cutaneous perforators for overlying skin are not part of the muscle flap (skin/fascia cover is separate). (Hanson) - Choke vessels/angiosomes: rich anastomoses exist between the deep temporal network and superficial temporal/middle temporal systems; the middle temporal artery can provide additional coverage to the deep temporal fascia when preserved. (Hanson) - Nerves: - Motor: deep temporal nerves (branches of mandibular division V3) enter the muscle at the infratemporal crest supplying temporalis motor function; dual innervation typically present. Preserve if dynamic function is desired (lengthening myoplasty). (Panossian; Hanson) - Sensory: auriculotemporal nerve supplies the overlying temporal skin and can be identified/preserved or included if a sensate fascial component is planned. Facial nerve frontal branch lies superficial to zygomatic arch and must be avoided during incisions and dissection of overlying tissues—relevant for coronal approach. (TPFF/Perforator chapters; Panossian) - Included tissues / anatomic configuration: - Muscle only (standard temporalis muscle flap) — fan-shaped muscle spanning temporal fossa. Typical whole-muscle dimensions reported: length 12–16 cm; thickness 0.5–1.0 cm. (Hanson) - Typical transferred strip: a central strip of temporalis from the middle third is commonly elevated for reanimation — approximately 4–5 cm wide to minimize temporal hollowing. (Panossian) - Tendon: broad conical temporalis tendon wraps over the coronoid process; tendon is used for anchoring to oral commissure/upper lip in reanimation procedures. (Panossian) - Variants: split temporalis flap, temporalis with periosteal extension (1–3 cm periosteal extension into parietal area described), composite options with temporoparietal fascia or grafts (e.g., fascia lata interposition) when length is insufficient. (Panossian; Hanson) - Arc of rotation: for retrograde (turnover) transfer the muscle/tendon is passed over the zygomatic arch into the buccal/upper lip region; for lengthening (orthodromic) myoplasty the tendon is advanced distally to the nasolabial fold via an infrabuccal tunnel. Osteotomy of the zygomatic arch and/or coronoidectomy may be used to increase excursion/visualization. (Panossian) - Common variants/anomalies: - Dual vascular (anterior/posterior deep temporal arteries) and dual innervation common; accessory middle temporal artery variance may affect deep temporal fascia blood supply. Ipsilateral internal maxillary or external carotid sacrifice will compromise flap vascularity. (Hanson; Panossian) ## Dissection Steps 1. Positioning, markings, landmarks. - Position: supine with shoulder roll to gently extend the neck; endotracheal tube secured midline. (Panossian) - Markings: - For reanimation, mark desired nasolabial fold and vector of smile based on contralateral side or simulated smile. Tattoo key points with gentian violet/25‑gauge needle as desired. (Panossian) - Mark coronal anterior hairline incision and optional preauricular extension (facelift-type). Alternative: coronal incision alone with nasolabial counterincision. (Panossian) - Palpate temporalis during clenching to identify insertion near midpoint of zygomatic arch; superior margin ≈ halfway between upper margin of ear and vertex. (Hanson; Panossian) - Tumescent: inject epinephrine in dilute solution (reported range 1:500,000 to 1:1,000,000) over temporalis and midface to assist hemostasis; avoid local anesthetic agents that may impair muscle function if intraoperative stimulation is planned. (Panossian) 2. Plane (suprafascial/subfascial), perforator identification (handheld/IO Doppler). - Skin flap elevation: elevate anterior and posterior scalp/temporal skin flaps in a deep subcutaneous plane that proceeds along the superficial layer of the deep temporal fascia; preserve the superficial temporal fat pad with the skin flap to minimize temporal hollowing. (Panossian; Hanson) - Transition to subperiosteal: continue anteriorly in a subperiosteal plane onto lateral orbital rim, zygoma, and zygomatic arch until superficial surface of temporalis visualized. (Panossian) - Identify temporalis tendon at the infratemporal crest and beneath masseter fiber contributions (lengthening myoplasty). (Panossian) - Elevation of muscle: designate a central strip ≈4–5 cm wide (middle third) for elevation; include periosteal extension if needed (1–3 cm). Elevate muscle in superior→inferior subperiosteal direction. Use periosteal scoring near infratemporal crest to increase mobility while avoiding injury to neurovascular pedicles. (Panossian) - For lengthening myoplasty, elevate whole temporalis from fossa with periosteal elevator and identify dual neurovascular supply at infratemporal crest (use nerve stimulator to localize deep temporal nerves). (Panossian) 3. Pedicle dissection: exposure, control, division; transfer/inset; perfusion checks. - Preserve deep temporal arterial pedicle(s) running on the deep surface of the muscle. Avoid injuring vessels from cranial base during periosteal release. (Panossian) - Create subcutaneous tunnel for transfer: - Retrograde/turnover temporalis flap: create subcutaneous tunnel over zygomatic arch; a transverse release in deep temporal fascia increases length available. Turn muscle over zygoma and pass to nasolabial/oral commissure site. (Panossian) - Orthodromic lengthening temporalis myoplasty: perform zygomatic arch osteotomy (oblique anterior/posterior cuts leaving masseter attached inferiorly) to expose/identify true tendon; perform coronoidectomy if needed to release tendon and gain distal length. Create wide tunnel from nasolabial fold through buccal space toward infratemporal space and deliver coronoid‑attached tendon through tunnel. (Panossian) - Tendon handling: - For lengthening myoplasty: place atraumatic vascular clamp along tendon proximal to coronoid to prevent retraction; strip tendon from coronoid with scalpel/Freer; open conical tendon and trim loose strands to create broad surface for anchoring. (Panossian) - For turnover flap with insufficient length: prepare intervening graft (fascia lata or palmaris longus). Fascia lata harvest described using two incisions with distal counterincision approx 10 cm proximal to lateral femoral condyle; a 3–4 cm wide length of fascia lata commonly harvested. Palmaris longus harvest via 1‑cm proximal wrist crease incision and a 1‑cm mid‑forearm incision described when present but is narrow for wide attachment. (Panossian) - Anchoring and inset: - Place 3–4 anchoring sutures (0 or 2‑0 PDS or equivalent) along oral commissure and upper lip in figure‑of‑8 fashion to simulate desired smile vector. (Panossian) - Secure graft to distal muscle or tendon using several 4‑0 Vicryl U‑stitches to protect against cheesewire, then 2‑0 PDS figure‑of‑8 to anchor; reinforce with running 5‑0 nylon/Prolene as required. (Panossian) - Test construct intraoperatively with percutaneous muscle stimulator and adjust anchoring sutures to optimize vector/excursion. (Panossian) - Perfusion checks: intraoperative muscle stimulation for motion; visual assessment of muscle color/bleeding. (Panossian) - If zygomatic arch osteotomy performed, fix with plates/wires at completion. (Panossian) 4. Donor-site closure techniques. - Replace temporoparietal fascia or use implant/temporoparietal fascial flap to fill donor defect if necessary; place closed channel drain in temporalis fossa. (Panossian; Hanson) - Indwelling local anesthetic delivery catheter may be inserted near neurovascular bundle to reduce postoperative spasm. (Panossian) - Layered closure of coronal and preauricular incisions; drains commonly removed at 2 days postoperatively. (Panossian) ## Indications and Contraindications - Indications: - Facial reanimation for long‑standing (permanent) facial paralysis — typically for paralysis >18 months (Panossian). Both retrograde temporalis flap (turnover) and lengthening temporalis myoplasty (orthodromic) are used to restore oral commissure/upper lip excursion; minimum age for lengthening procedure ≈5 years. (Panossian) - Temporalis muscle flap (whole or split) for head & neck reconstruction: orbital/periorbital reconstruction, orbital exenteration coverage, external cheek defects, cranial base, maxilla, palate, floor of mouth, retromolar trigone, tonsillar fossa, posterior oropharynx, tongue, and eyelid/lid sling. Dynamic slings for lower eyelid/lip can use split temporalis. (Hanson) - When a thin, vascularized, locally available muscle is preferred over free tissue transfer, or when dynamic transfer with trigeminal motor innervation is desired. (Hanson; Panossian) - Use as local pedicled flap or combined chimeric flap with temporoparietal fascia or calvarial bone as indicated. (TPFF/Perforator chapters) - Size limits / tissue characteristics: - Muscle length 12–16 cm; thickness 0.5–1.0 cm. Typical elevated strip for reanimation 4–5 cm wide. (Hanson; Panossian) - Use when thin/moderate bulk is needed rather than large-volume reconstruction. - Contraindications: - Compromise of ipsilateral arterial inflow: prior sacrifice/ligation of ipsilateral internal maxillary artery or external carotid system that supplies deep temporal arteries makes flap unreliable. (Hanson; Panossian) - Prior surgery or radiation compromising regional vasculature: relative contraindication—reduced viability and increased risk of complications. (TPFF/Perforator and Hanson) - Severe comorbidity precluding prolonged surgery or osteotomy/coronoidectomy when required. ## Postoperative Care - Immediate: - Closed drains and anesthetic pump catheter removed at 2 days postoperatively (Panossian). Dressings per standard head/neck practice. - Monitor for muscle spasm/tension on repair — early transient overcorrection can occur and typically resolves over 2–3 months. (Panossian) - Monitoring schedule / method: - Clinical monitoring of flap/tendon motion and wound; intraoperative stimulator testing demonstrates expected excursion — postoperative clinical assessment is the mainstay. (Panossian) - No specific implanted Doppler or implantable probes described for temporalis muscle flap in the provided texts. - Warming/antithrombotic practice: - Specific systemic antithrombotic protocols are not detailed in the cited material for this flap; use institutional standards for head and neck reconstructive procedures. - Positioning / splinting: - Avoid tension on repairs; head positioning per surgeon preference (supine to semi‑elevated) to minimize edema. - Drains / mobilization / diet / analgesia: - Drains removed post‑op day 2. Avoid contact sports and hard foods for 6 weeks. Analgesia and local anesthetic catheter as described to reduce spasm. (Panossian) - Begin facial therapy (muscle retraining/mime therapy, biofeedback) at 3–4 weeks post‑op; avoid aggressive massage at insertion early. (Panossian) - Return-to-OR thresholds and time windows: - Tendon avulsion or lack of visible movement with loss of nasolabial fold may present early (avulsions described occurring within first 4 weeks). Revision for adhesiolysis and tendon reimplantation is typically deferred until no sooner than 6 months postoperatively (allow healing and maturation) unless acute salvage is indicated; the cited texts recommend revision at ≥6 months for adhesions/avulsion. (Panossian) ## Complications (rates & management) - Reported/observed complications (qualitative; numeric frequencies not provided in temporalis chapters): - Temporal hollowing — most commonly reported aesthetic donor complaint; minimized by preserving anterior third of muscle and temporal fat pad. (Hanson; Panossian) - Adhesions of temporalis tendon in subzygomatic/infratemporal space limiting excursion. (Panossian) - Avulsion of temporalis tendon insertion (may occur early with muscle spasm and countertension from contralateral facial muscles) — typically occurs within first 4 weeks. (Panossian) - Spasm of transferred muscle causing temporary overcorrection; resolves over 2–3 months. (Panossian) - Bulk over zygomatic arch region after flap creation (expected). (Panossian) - Aesthetic scarring, loss of mobility, persistent asymmetry, unusual facial dimpling. (Panossian) - Donor-site issues: temporal hollowing, contour deformity; seroma/hematoma are possible but not numerically quantified. Preservation of temporal fat pad and anterior muscle reduce hollowing. (Hanson; Panossian) - Management algorithms: - Tendon avulsion / persistent failure of motion: - Initial conservative observation if early and tendon avulsion suspected but clinical context permits (spasm may settle); if persistent loss of motion and deformity, revision surgery (adhesiolysis and tendon reimplantation) considered — cited timing: revision no sooner than 6 months postoperatively. (Panossian) - Adhesions limiting excursion: - Surgical adhesiolysis and release; tendon reattachment if required — recommended no sooner than 6 months unless acute indications. (Panossian) - Infection / wound complications: - Standard surgical wound care and antibiotics per head & neck protocols (not specifically detailed in provided texts). - Venous congestion / arterial thrombosis / flap loss: - Specific salvage strategies (leech therapy, thrombolysis, immediate re‑exploration) are not described for this flap in the provided references — institutional microsurgical/free‑flap salvage principles apply when applicable. - Reported rates: - The supplied sources do not provide specific numeric complication rates for temporalis muscle flap outcomes. ## Key Clinical Pearls - Preserve the temporal fat pad with the scalp skin flap to minimize postoperative temporal hollowing; avoid raising the anterior third of the muscle when possible — typical transfer is a central strip ≈4–5 cm wide. (Panossian; Hanson) - Identify and preserve the deep temporal nerves (V3) when dynamic function is desired; use a nerve stimulator intraoperatively to localize motor branches at the infratemporal crest. (Panossian) - Maximize distal reach before harvesting an intervening graft: perform periosteal scoring at the infratemporal crest and consider a transverse release in the deep temporal fascia; periosteal extension of 1–3 cm into parietal area is commonly used to gain length. (Panossian) - When tendon length is insufficient, use fascia lata graft (3–4 cm wide commonly harvested) rather than narrow palmaris longus when a broad attachment surface is needed; palmaris longus can be used if present but provides a narrow tendon. (Panossian) - Use 3–4 anchoring sutures (0 or 2‑0 PDS) in figure‑of‑8 along oral commissure/upper lip to set the vector; protect distal attachment with 4‑0 Vicryl U‑stitches to avoid cheesewiring before final 2‑0 PDS figure‑of‑8 and 5‑0 nylon reinforcement. (Panossian) - Test and fine‑tune vector and tension intraoperatively with percutaneous muscle stimulation; aim for slight under‑ or exact correction because early spasm may produce temporary overcorrection. (Panossian) - Anticipate and counsel patients about expected bulk over zygomatic arch postoperatively and the natural course: spasm settles over 2–3 months and excursion improves over months to years (further improvements reported up to 1–3 years). (Panossian) - Rehabilitation: begin facial retraining (mime therapy, biofeedback) at 3–4 weeks to prevent adhesions and optimize functional reeducation; avoid aggressive massage at insertion site early. (Panossian)