Frontofacial surgery in children and adolescents: techniques, indications, outcomes

Abstract

The techniques of frontofacial surgery are most valuable in the clinical management of complex craniofacial deformity to achieve a range of functional and aesthetic gains in children from infancy to maturity. A variety of complex craniofacial osteotomies that can be used to separate the orbits from the skull base have been described. In addition, the combination of circumorbital release and pterygomaxillary disjunction allows advancement of the orbitomaxillary segment for powerful clinical benefit. For the purpose of this article, the principal frontofacial strategies include the monobloc frontofacial advancement by distraction (MBD), frontofacial bipartition advancement by distraction (BpD), orbital box osteotomy (FFBx), and frontofacial bipartition (FFBp). These techniques are broadly used for two purposes: to allow for the translocation of one or both orbits to correct orbitofacial disproportion (hypertelorism, vertical orbital dystopia, or a combination of both), or to advance the orbitomaxillary segment for orbital volume expansion and protection of the eye in syndromes featuring severe exorbitism (oculo-orbital disproportion). Here we describe aspects of our experience of frontofacial surgery in the Craniofacial Centre at Great Ormond Street Hospital for Children, London, with reference to the principles underpinning frontofacial surgical techniques, their challenges, and their impact on function and aesthetics.

Keywords: Apert syndrome; Crouzon syndrome; Pfeiffer syndrome; hypertelorism; monobloc; orbital dystopia.

Fig. 1

Three-dimensional skull model. Red line shows 'internal' circumorbital osteotomies: orbital roof (accessed via transfrontal osteotomy), to medial wall posterior to posterior lacrimal crest, to orbital floor though anterior aspect of inferior orbital fissure, to lateral wall and back up to orbital roof. The blue line shows the osteotomy for one type of frontofacial box (see text).

Fig. 2

Axial computed tomography scan. Single red line shows medial wall osteotomy through ethmoid complex, posterior to the posterior lacrimal crest. Double red line shows lateral wall osteotomy, the anterior line as for frontofacial monobloc or bipartition distraction to carry the bone but not the globe; the posterior line as for box osteotomy to carry the contents of the 'effective orbit'.

Fig. 3

(A–C) Three types of box osteotomy design. (A) Midline excision of bone, osteotomies to carry the zygoma in entirety and narrow the bimalar distance. The anterior maxillary osteotomy is a closing wedge below the infraorbital nerve. (B) The inferior border of the zygoma is not carried, leaving a wider bimalar width (suiting a male face). The osteotomy is superior to the infraorbital foramen, as might be the case with a high canine tooth root. (C) Asymmetric design with microphthalmos. A midline strut is preserved as a reference point to build toward in the reconstruction.

Fig. 4

(A–E) Shows complete monobloc osteotomies through the (A) orbital roof, (B) laterally through the lateral orbital walls, (C) the zygomatic arch, (D) the pterygoids, and (E) showing the distraction wires in the medial buttress of the maxilla.

Fig. 5

The three-dimensional computed tomography scan in lateral view shows the frontal craniotomy and plate fixation to the monobloc segment in an advanced position. The zygomatic arch is shown sectioned in lateral view, and the advanced maxillary position optimizes the jaw relationship for subsequent orthognathic surgery.

Fig. 6

The facial bipartition. The frontal “D” craniotomy has been performed. The facial segment has been cut as a monobloc, with a central V of bone removed from craniotomy cut to the rhinion (osseocartilaginous junction of the nose). The shape of the V determines the arc of medialization of the orbits.

Fig. 7

Clinical image of child with Crouzon-Pfeiffer syndrome, with constricted orbital hypoplasia and oculo-orbital disproportion. The constricted orbit predisposes to palpebral insufficiency, ocular surface exposure, and extremely ocular subluxation. The panel of axial computed tomography scans demonstrates the inadequacy of orbital volume and shape and degree of exorbitism, with skeletal support behind the equator of the globe.

Fig. 8

(A,B) Vertex view of an adolescent with Apert syndrome, (A) pre- and (B) postfrontofacial bipartition. The midface has been advanced differentially and the upper eyelid given a mechanical and functional advantage. The lateral canthus has been elevated relative to the medial canthus, and the nose is advanced. Nasal and forehead balance is improved.

Fig. 9

(A–C) Intraoperative panel. (A) Coronal flap reflected to show ink marks of planned orbital access and expansion with elevation. The periorbita soft tissues fill the orbit in the reflected soft tissue flap. (B) Frontal craniotomy removed for orbital roof access. (C) Postreconstruction with frontal craniotomy replaced and fixed with the supraorbital margin elevated (black arrow). The periorbita are flanked by a medial space (white arrow) showing the effective orbital expansion.