• 1.

  Incision: Preauricular crease incision anterior to the tragus from the helical root to the tragal base; extend as an inverted hockey-stick into the temporal hairline for greater superior exposure. Endaural or inviscision variants may be used for esthetic preference.

• 2.

  Dissection planes: Develop 2 connected planes—superiorly, deep to the temporoparietal fascia down to the temporalis fascia; inferiorly, on the avascular, nerve-free tragal perichondrium directly to the lateral capsule. The tragal pointer confirms the facial nerve (∼1 cm deep, ∼1 cm inferior).

• 3.

  Zygomatic arch exposure: Incise temporalis fascia and muscle to bone and elevate subperiosteally over the lateral arch—the principal facial nerve protection maneuver—to reach the articular eminence. Palpate the condyle before entering the joint to avoid the external auditory canal and middle ear.

• 4.

  Capsular entry. After elevating the parotid off the capsule, make a T-shaped capsulotomy; the horizontal limb over the eminence exposes the superior space and a lateral limb exposes the inferior space when disc access is required. Place a malleable retractor medial to the neck to protect the maxillary artery, pterygoid venous plexus, and middle cranial fossa.

• 5.

  Closure. Reapproximate capsule, periosteum, fascia, subcutis, and skin in layers; pressure dressing for 24 hours.

This approach provides direct line-of-sight access to the condyle through an intraoral incision, eliminates the facial scar, and reduces risk to the facial nerve. It is best suited to high and proportional condylectomy for hyperplasia and to small, superiorly based osteochondromas, and is not appropriate for oncologic resection or for lesions requiring access to the fossa or skull base.

• 1.

  Incision: Vestibular incision along the external oblique ridge from mid-ramus to the first molar.

• 2.

  Exposure: Subperiosteal dissection of the lateral ramus, sigmoid notch, and coronoid base.

• 3.

  Coronoidectomy: Strip the temporalis from the coronoid and osteotomize it at its base, removing it to create a direct corridor to the condylar head.

• 4.

  Endoscopic orientation: Advance a rigid endoscope (2.7 mm, 0°, or 30°) along the medial ramus to visualize the medial and posterior surfaces inaccessible to direct view.

• 5.

  Guide placement: Seat the virtual surgical planning (VSP)–derived patient-specific cutting guide on the condylar head and confirm circumferential seating endoscopically, with particular attention to the medial pole; provisionally fixate ( Figs. 1 and 2 ).

  

  Computer-aided design of surgical guide to direct the proportional condylectomy via intraoral approach.

  

  Intraoral access to a proportional right TMJ condylectomy using endoscopic assistance and bone-borne surgical guides.

• 6.

  Osteotomy: Position a malleable retractor medial to the condylar neck, then cut through the guide slot under endoscopic visualization, preserving the medial cortex.

• 7.

  Specimen and hemostasis: Release the lateral pterygoid, deliver the specimen intraorally (in 2 pieces if large), and control bleeding with packing, bipolar cautery, and topical hemostatic agent; remain mindful of the masseteric, pterygoid, and internal maxillary vessels.

• 8.

  Closure: Resorbable closure of the vestibular incision; the coronoid is not replaced. If circumferential guide seating or the osteotomy cannot be completed safely, convert to the extraoral approach ( Fig. 3 ).

  

  Endoscopic-assisted intraoral approach. A BSSO-style vestibular incision exposes the lateral ramus and coronoid; the coronoid is removed, and the resulting window provides a direct corridor for endoscopically assisted access to the condyle.

Pearl: Approach selection should never compromise the completeness or orientation of the resection; visualization and precision take precedence over incision choice.

Activity is established through serial clinical examination, serial radiographs, and advanced imaging. High-resolution computed tomography (CT) scan or cone beam computed tomography (CBCT) defines condylar morphology and excludes neoplasm; MRI assesses disc position and joint degeneration. Bone scintigraphy with single-photon emission computed tomography (SPECT) estimates relative metabolic activity—relative condylar uptake greater than ∼55% suggests active growth, whereas equivocal findings (50%–55%) are not, by themselves, an indication for resection and warrant serial examination with repeat imaging at 6 to 12 months until progression is documented (algorithm 1) ( Fig. 4 ). VSP is the default planning modality; 3-dimensional simulation defines osteotomy orientation and volume, predicts mandibular autorotation and occlusal change, and generates patient-specific cutting guides ( Figs. 5 and 1 ).

Image on the left is a 3-dimensional reconstruction of a CT of the facial bones showing mandibular asymmetry and a left posterior open bite, consistent with left condylar pathology versus hyperplasia. The image on the right showcases a SPECT-CT with evidence of increased growth activity in the left condyle (71% compared to 29%).

VSP session demonstrating the projected condylectomy. The last image is an intraoperative photograph of the completed condylectomy cut, before delivery of the specimen.

Two variants address active CH. High condylectomy removes the superior 3 to 5 mm of the condylar head, including the presumed hyperactive growth center, and typically requires a secondary orthognathic procedure to correct residual asymmetry. ^, Proportional condylectomy removes a VSP-defined wedge calculated to restore symmetric condylar height in a single stage, preserving sufficient height for joint stability and occlusal normalization ( Fig. 6 ). In either variant, the osteotomy is oriented perpendicular to the long axis of the condylar neck; a malleable retractor is placed medial to the neck before the saw; the lateral pterygoid is released if indicated; and a viable disc is preserved whenever possible. Temporary occlusal guidance before closure confirms midline alignment and cant reduction—the single most reliable safeguard against residual asymmetry. Either corridor described above may be used.

Osteotomy orientation for condylectomy variants. ( A ) High condylectomy removes the superior 3 to 5 mm perpendicular to the long axis of the condylar neck. ( B ) Proportional condylectomy removes a VSP-planned wedge to restore symmetric condylar height. ( C ) Complete condylectomy is performed at the neck and requires immediate reconstruction. In all variants, a retractor is positioned medial to the neck before the saw.

In correctly selected patients, condylectomy stabilizes mandibular growth and improves symmetry, and recurrence is uncommon when biologic activity has been accurately identified. ^, Reported complications include transient facial nerve weakness, occlusal instability, and persistent asymmetry from incomplete resection.

Pearl: The objective is not to shorten the condyle but to eliminate the active growth center while preserving joint function; planning must account for how mandibular autorotation will affect the posterior occlusion.

Pitfall: Under-resection is more common than over-resection and is the usual cause of persistent deviation or the need for secondary surgery.

Osteochondroma typically presents with progressive facial asymmetry, mandibular deviation, occlusal cant, and a contralateral posterior open bite. Unlike the diffuse overgrowth of hyperplasia, it is a focal exophytic lesion arising from the condylar head, characterized radiographically by continuity of cortical and medullary bone with the underlying condyle. High-resolution CBCT defines lesion extent and its relationship to the glenoid fossa; MRI evaluates disc displacement and joint integrity.

The operative objective is complete excision while preserving uninvolved joint structures, with resection level dictated by structural involvement of the condylar head rather than tumor size (algorithm 2). Small pedunculated lesions with a preserved condyle are managed by local excision and contouring; sessile lesions involving part of the head with a preserved neck are treated by proportional condylectomy with a VSP wedge; extensive lesions that destroy the head or extend into the neck require complete condylectomy with immediate reconstruction. Recurrence after complete excision is rare; incomplete resection of the cartilaginous cap is the most common cause of persistent deformity.

Pearl: The choice among local excision, proportional condylectomy, and complete condylectomy should be based on structural involvement of the condylar head, not tumor size alone.