The Evaluation, Correction, and Prevention of Pathologic Facial Development Secondary to Craniosynostosis

Clinical Findings

Endoscopic Versus Open

Endoscopic craniectomy with a sagittal strip removal and biparietal anterior and posterior wedges followed by helmet therapy has proven to be very effective in this patient population when treated early (<6 months). The advantages of endoscopic minimally invasive treatment are decreased operating room (OR) time, hospital stay, decreased cost, decreased blood loss and transfusion rates, and a decreased reoperation rate. ^{, ,}

Cranial vault remodeling surgery is also effective for the treatment of sagittal synostosis; however, the disadvantages include increased length of hospital stay, increased blood loss and transfusion rates, increased OR time, and a later surgery date which permits the deformity and effects on the developing brain to persist for a longer period of time prior to operation. ^{, ,}

Both endoscopic and open groups have comparable aesthetic outcomes and both groups demonstrate equal regression at 3 years postoperatively.

Required Facial Surgeries

The frontal bossing which characterizes this deformity is usually corrected by the original cranial surgery. Additionally, the frontonasal angle tends to self-correct following the original cranial surgery, whether endoscopic or open.

As the child develops, they should continue to be monitored by the craniofacial team on a yearly basis. The facial deformities are generally mild; however, augmentation of the bitemporal areas may be desirable and this can be effectively accomplished with either cranial implants or bone cement. Awaiting near completion of cranial growth is recommended, i.e., after 5 years of age.

Cranial Findings

Trigonocephaly with posterior biparietal and bitemporal widening and anterior bitemporal narrowing. The anterior fossa is typically narrowed and shortened with a pseudoencephalocele-type formation resulting in frontal lobe growth restriction.

Facial Findings

Facial findings include: superolateral retraction of the bilateral superior orbital rim and brow, bitemporal narrowing/hallowing appearance, frontal metopic ridging, hypotelorism with or without presence of epicanthal folds, decreased width of choanae and nasal piriform aperture, and the ears are commonly prominent and overprojected. Little to no change of lower facial third is noted ( Fig. 2.3A–E ).

Intracranial Pressure Findings

Increased ICP is present in approximately 8% to 33% of metopic synostosis patients. ^{, , ,} The severity of the phenotype is not necessarily indicative of the severity of the pathology (raised ICP or associated developmental delays). Even in mild cases of nonsyndromic metopic synostosis, if clinical symptoms were also present, an increase in ICP was found in 91% of the patients tested.

Developmental Findings

Metopic suture synostosis is linked with a high percentage of neurodevelopmental delays at 57%. ^, Even mild metopic synostosis is known to be associated with language delay (most common in metopic synostosis), hyperactivity, autistic tendencies, self-mutilation, motor delay, panic, and irritability. Though debated, it has been demonstrated that even late repair will aid in ameliorating these symptoms; however, it has also been shown that earlier correction results in greater developmental recovery of the patient with very little recovery after the age of 8 years. ^, Generally, developmental delays in the mild metopic subgroup are not seen until after the first year of life.

Radiological Findings

Full fusion will go from nasion to bregma and typically causes hypotelorism and lateral superior orbital rim retraction ( Fig. 2.4A ). Typically, an endocranial ridge may be seen both in normally and prematurely fusing metopic sutures, whereas an endocranial notch is generally only seen in abnormally fusing metopic synostoses ( Fig. 2.4B ). When compared with control groups, there is a significant decrease in the intercoronal distance (ICD; distance between the outer surfaces of the coronal sutures), and the cephalic width (CW)/ICD ratio was indicative of which patients received surgery ( Fig. 2.4C ). A ratio of 1.25 was the average that received surgical treatment, whereas 1.19 was the average in the normal population and the observational cohort. In the more severe patients, interdacryon and inter-zygomaticofrontal suture distance are decreased when compared with controls, though this is not true for the mild and moderate group. The endocranial bifrontal angle has been shown to differentiate moderate trigonocephaly patients from the control group ( Fig. 2.4D ).

Endoscopic Versus Open

Open repair for metopic suture synostosis is generally performed between 6 and 12 months of age with the use of a fronto-orbital bandeau and anterior cranial vault remodeling. The older the patient the more stable the repair. Unfortunately, delaying may have untoward developmental affects and may also contribute to the persistence of orbital hypotelorism. However, satisfactory results with only slight residual deformities of the forehead and bitemporal hollowing being noted are possible. Residual hypotelorism is common. ^,

Endoscopic correction has the advantage of being able to be performed at a much younger age. Early treatment aids in near complete correction of orbital hypotelorism (93%), as well as providing earlier relief to a restricted brain. ^, Additionally, the endoscopic approach advantages include: decreased OR time, hospital stay, cost, blood loss and transfusion rate, and a decreased reoperation rate. ^,

Required Facial Surgeries

As the child develops, they should continue to be monitored by the craniofacial team on a yearly basis. The facial deformities are generally mild; however, augmentation of the lateral orbital region and bitemporal areas may be desirable and this can be effectively accomplished with either cranial implants or bone cement. Awaiting near completion of cranial growth is recommended, i.e., after 5 years of age. Cranial implants are preferable due to their lower infection rate, more reliable outcomes, and the ability to plan and fabricate virtually.

The persistent hypotelorism deformity seen in many of these patients is generally mild and late correction is not generally justified.