Staged Surgical Correction of Severe Panfacial and Transverse Nasal Root Asymmetry in Unicoronal Synostosis.

Nasal asymmetry is widely acknowledged to be one of the most difficult deformities to manage. Most reports in the literature pertain to corrective methods in relation to isolated deformity of the dorsum in the posttraumatic patient. There is a paucity of literature relating to management of nasal radix asymmetry, and still less in the context of severe panfacial asymmetry.

Takeaways

Question: How can a transverse nasal root asymmetry be evaluated and managed, particularly as part of a panfacial asymmetry?

Findings: Diagnosis was based on thorough clinical evaluation and photographic manipulation comparisons. The nasal root was osteotomized and medialized by 6 mm via a bicoronal flap to improve a severe nasal asymmetry. This was undertaken in conjunction with unilateral forehead reduction, contralateral forehead augmentation and unilateral browlift. The patient subsequently had orthognathic surgery to correct her mid/lower facial asymmetry.

Meaning: When accurately diagnosed and planned, the transverse nasal root osteotomy rhinoplasty technique is an effective tool for improving nasal symmetry.

We present details of a patient with a developmental cause for asymmetry in all thirds of the face, including significant nasal root asymmetry. The nasal root was translated toward the facial midline by means of a one-piece transverse root osteotomy, which, to our knowledge, has been described only once previously in this context. Comprehensive management of the upper and lower facial third asymmetry is also described.

CASE HISTORY

A 23-year-old female patient was referred to our clinic (Fig. 1). She provided a history of a right unicoronal craniosynostosis, operated with fronto-orbital advancement and remodeling at the age of 18 months. Her main complaint was that her nose, eyes, and eyebrows appeared asymmetric. She was also concerned about the asymmetry of her jaws and smile, although this was a secondary concern. Clinical examination revealed a flat/concave right supraorbital ridge and forehead, and bossing of the left side of her frontal bone. Her left eyebrow was significantly ptotic, with the highest point of her left eyebrow measuring 5 mm lower than the highest point of her right eyebrow. The lower half of her nose was relatively symmetrical, with a significant deviation of the nasal root to her right side. The maxilla was significantly translated to her left side, with a relatively level maxillary occlusal plane, and her mandible and chin were significantly to her left. Collectively, the upper third asymmetry gave the illusion of vertical orbital dystopia.

Fig. 1.

Clinical photograph at the initial examination, demonstrating the nasal root asymmetry to the patient’s right side. The left brow was 5 mm lower in position than the right brow. The lower facial asymmetry was with the maxilla, mandible and chin significantly to the patient’s left side.

Clinical treatment planning was aided with a Vectra 3D camera and image manipulation, which confirmed that translating the nasal root towards the midline was the key to improving the nasal symmetry (SDC 1). (See figure, Supplemental Digital Content 1, which displays image manipulation using a Vectra 3D camera, demonstrating nasal root movement towards the midline and nasal dorsal correction maintaining the original nasal root position, http://links.lww.com/PRSGO/C45.) A series of operations to reduce the appearance of facial asymmetry were planned and agreed upon with the patient.

In the first surgical procedure, a one-piece nasal osteotomy was performed via a bicoronal and external nasal approach, allowing direct visualization and access, to centralize the root of the nose between the medial canthi. The osteotomy was made anterior to the nasolacrimal crest, completely through the nasal septum, allowing the radix to be repositioned 6 mm toward the midline. It was fixed using an X-shaped plate, and any small irregularities were filled with calcium phosphate cement.

To address the asymmetry of the forehead/brow region, a PEEK implant was placed over the right side of the forehead/brow region for augmentation of the frontal bone and the left side was reduced to provide symmetrical projection of the forehead. Fat grafting was considered but the authors find it unpredictable in its stability long-term, hence opting for a more predictable long-term outcome with the PEEK implant. Her left brow was lifted to be level with her right brow. A 4-0 Ethibond suture was used to elevate the lateral aspect of the left brow. The periosteum was sutured to a 4 × 1.3 mm screw. Slight over elevation was achieved to allow for relapse. These procedures were undertaken via the same bicoronal approach.

Subsequently, and following orthodontic preparation of the dental arches, the second surgical procedure undertaken was a Le Fort I-type osteotomy used to translate the maxilla 7 mm to the patient’s right, together with a small advancement. A bilateral sagittal split osteotomy was used to rotate the mandible and chin toward a Class I position. The nasal septal correction was addressed at the time of the bimaxillary osteotomy via the Le Fort I approach, which provides direct access to the whole of the septum from the inferior aspect. The septum was repositioned and fixed in position to the anterior nasal spine, which had itself been translated toward the facial midline as part of the Le Fort I osteotomized segment. A closed rhinoplasty with alar wedge resection was performed to improve the symmetry of the alar base. The patient made an uneventful recovery and was satisfied with the final postoperative result (Fig. 2; SDC 2). (See figure, Supplemental Digital Content 2, which shows the preorthognathic correction and the end of treatment, http://links.lww.com/PRSGO/C46.) She experienced no temporomandibular joint symptoms or functional nasal problems. Follow-up to date has been for 2 years after completion of the bimaxillary osteotomy.

Fig. 2.

Comparative analysis. A, Pretreatment. B, Following nasal root translation, forehead, and brow procedures. The upper face and nasal root are now relatively symmetrical. The maxillary dental midline is 7 mm to the patient’s left, and the mandibular dental midline and chin midpoint are 9 mm to her left. C, Facial symmetry following the maxillomandibular orthognathic procedures.

DISCUSSION

Unicoronal synostosis results in underdevelopment of the ipsilateral anterior cranial fossa, and compensatory overgrowth along other cranial vault sutures.[1] In the upper face, this manifests as a flat forehead, elevated brow, posterosuperiorly displaced orbit on the affected side (causing an interpupillary cant), with contralateral frontal bossing. In the midface the ipsilateral zygomatic arch is shortened but the zygoma itself slightly advanced. The base of the nose is drawn towards the synostotic side, whereas the tip of the nose and maxilla are rotated towards the side of the unfused suture.[2] In the lower face, anteroposterior shortening of the ipsilateral mandibular ramus, and anterior displacement of the temporomandibular joint results in a mild Class III jaw relationship, often with chin point deviation towards the contralateral side.[2] In summary, the resultant facial scoliosis involves complex asymmetry in all facial thirds—retrusion and superior displacement of the ipsilateral upper third, advancement and downgrowth of the contralateral upper third, and rotation of the middle and lower thirds toward the nonfused side. This constellation of deformities often remains apparent despite fronto-orbital advancement surgery in infancy[3] and presents a particular challenge for holistic revision surgery later in life.

In this case, digital treatment planning using 3D imaging was helpful in virtually trialing a number of surgical options to identify a treatment plan that would resolve the most noticeable components of the asymmetry. This was crucial as there was no unaffected frontal facial plane to use as a baseline. Tessier previously remarked regarding unicoronal synostosis, “In the final analysis, everything is abnormal: malformed or deformed.”[4] Through digital manipulation it was discovered that translating the nasal radix toward the midline resolved much of the upper facial asymmetry. It was thus decided to accept the existing interpupillary plane and the inferior orbital rims as the soft tissue and skeletal horizontal reference planes, respectively, correcting the frontal, nasal, maxillary, and mandibular deformities relative to these planes.[5] To our knowledge, the transverse nasal root osteotomy via a bicoronal approach has been described only once in the literature.[6] Our procedure differs in that the root of the nose was divided with an osteotome, rather than a saw. In addition, Marchac et al[6] also used intranasal incisions, which we avoided. The nasal root osteotomy can be undertaken via facial nasal root incisions, if not part of a severe facial asymmetry requiring a bicoronal incision. Following surgical correction of the nasal root asymmetry, a facial midline vertical was also constructed through soft-tissue glabella and soft-tissue nasion to aid planning of the orthognathic procedures.

The inner canthus dystopia was not considered to be a major factor in the asymmetry, and correction of the position of the medial canthi is difficult and prone to relapse. In correcting the asymmetries, a balance between risks and benefits was discussed. The ear position is abnormal as with conventional unicoronal synostosis. However, the patient had long hair and did not comment on this as being one of her concerns.

Although a multitude of osteotomies (lateral, medial, and intermediate) and variations thereof (low-to-low, low-to-high, and high-to-low-to-high) have been previously described for addressing nasal bone position, these leave the central root of the nose unaffected. The transverse root osteotomy used in this case results in a single bony nasal segment cleaved just inferior to the nasion. This osteotomy allows freedom of movement at the radix, which can then be repositioned (and plated). As the patient did not have severe midface hypoplasia or significant malar asymmetry to correct, use of the transverse root osteotomy meant that there was surgical control of the nasal bones independent of the maxilla and rest of the midface.

CONCLUSIONS

Complex facial asymmetry resulting from nonsyndromic unicoronal synostosis was treated through a combination of frontal bone augmentation, bimaxillary osteotomy, and the rarely performed transverse nasal root osteotomy. Careful facial aesthetic analysis, and three-dimensional imaging manipulation was crucial to the successful planning of this case as it led to an understanding of the main component of this complex facial asymmetry.