Combined metopic and unilateral coronal synostoses: a phenotypic conundrum.
BACKGROUND
Most types of craniosynostosis cause predictable changes in cranial shape. However, the phenotype of combined metopic and unilateral coronal synostoses is anomalous. The purpose of this observational study was to better clarify the clinical and radiographic features of this rare entity.


METHODS
A retrospective review of a craniofacial database was performed. Patients with combined metopic and unilateral coronal synostoses were included in this study. Data collected included demographic information, physical and radiographic findings, genetic evaluation, treatment, and operative outcomes.


RESULTS
Of 687 patients treated between 1989 and 2010, only 3 patients had combined metopic and unilateral coronal synostoses. All patients were diagnosed through computed tomography on the first day of life. Phenotypic features included the following: (1) narrowed forehead with a prominent midline ridge, (2) severe bilateral brow retrusion with an acute indentation on the side of the patient coronal suture, (3) facial and nasal angulation similar to isolated unilateral coronal synostosis, and (4) anterior displacement of the ear on the fused side. In addition, the cranial vertex was deviated toward the side of the open coronal suture. Two patients had a head circumference below the 25th percentile; 2 of the 3 had a TWIST gene mutation consistent with Saethre-Chotzen syndrome. One patient was managed through fronto-orbital advancement and required a revision. The other 2 patients had early endoscopic release, followed by postoperative helmet therapy; one improved but still required open cranial remodeling. The other has near-normal phenotype, and no further surgery is planned.


CONCLUSIONS
Combined metopic and unilateral coronal synostoses present a rare and unusual phenotype. Although early intervention improves the deformity, revisional procedures are usually required.
From the Departments of *Plastic and Reconstructive Surgery, and †Neurosurgery, Boston Children's Hospital, Boston, MA.
Tina M
TM
Sauerhammer
Kamlesh
K
Patel
Albert K
AK
Oh
Mark R
MR
Proctor
John B
JB
Mulliken
Gary F
GF
Rogers
D000168:Acrocephalosyndactylia / Q000235:genetics; D002508:Cephalometry / Q000379:methods; D003393:Cranial Sutures / Q000002:abnormalities*; D003398:Craniosynostoses / Q000175:diagnosis* / Q000235:genetics / Q000601:surgery; D004431:Ear, External / Q000002:abnormalities; D005260:Female; D005500:Follow-Up Studies; D005546:Forehead / Q000002:abnormalities; D005624:Frontal Bone / Q000002:abnormalities*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D010294:Parietal Bone / Q000002:abnormalities*; D010641:Phenotype; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D051879:Twist-Related Protein 1 / Q000235:genetics
D009687:Nuclear Proteins; C103173:TWIST1 protein, human; D051879:Twist-Related Protein 1