The diagnosis CFND is established only after the presence of a mutation in the EFNB1 gene has been determined. Physical manifestations are not necessarily part of the diagnostic criteria, but can help guide in the right direction. This is due to the large heterogeneity between patients regarding phenotypic expression.

20% of the patients that present with CFND-like characteristics do not display a mutation in the EFNB1 gene. The group of patients diagnosed with CFND is thus often overestimated. However, it is important to distinguish this population from CFND for research purposes. On the other hand, especially in males, it is possible that someone is a carrier of the EFNB1 gene mutation yet does not present with any physical manifestations. Screening for the presence of an EFNB1 mutation is thus the most reliable method to establish the diagnosis CFND.

Genetic counseling or prenatal screening may be advised if there is a reason to suspect the presence of an EFNB1 gene mutation. Prenatal screening may be done by performing an ultrasound, where can be searched specifically for hypertelorism or a bifid nasal tip. However, this is quite difficult as facial involvement may not be obvious at such an early age, especially in cases with mild phenotypic presentation. The most definitive way to prove the presence of CFND is done by genetic testing, through amniocentesis and chorionic villus sampling. This however carries a greater risk of premature termination of the pregnancy.

The main diagnostic tools for evaluating FND are X-rays and CT-scans of the skull. These tools could display any possible intracranial pathology in FND. For example, CT can be used to reveal widening of nasal bones. Diagnostics are mainly used before reconstructive surgery, for proper planning and preparation.

Prenatally, various features of FND (such as hypertelorism) can be recognized using ultrasound techniques. However, only three cases of FND have been diagnosed based on a prenatal ultrasound.

Other conditions may also show symptoms of FND. For example, there are other syndromes that also represent with hypertelorism. Furthermore, disorders like an intracranial cyst can affect the frontonasal region, which can lead to symptoms similar to FND. Therefore, other options should always be considered in the differential diagnosis.

There is no ‘standard treatment’ for people with CFND due to the large variations in phenotypic expression. Each patient needs to be assessed and treated based on their specific presentation in order to restore the aesthetic and functional balance.

Surgical corrections for the main symptoms;

- Craniosynostosis correction: The preferred age for this procedure is between 6–9 months of age. Performing this surgery at such an early age can limit the further development of facial asymmetry, if the asymmetry is caused by the craniosynostosis, and prevents prolonged elevated intracranial pressure (ICP). However, the data for the exact risk of an elevated intracranial pressure for patients with CFND is lacking in the published literature. The surgery involves a frontal bone advancement in combination with remodellation of the supraorbital rim.

- Orbital hypertelorism: It is preferred to wait with this treatment until the age of 5–8 years old, after permanent dentition. The procedures that can be performed are the facial bipartition and the box osteotomy. Facial bipartition is the more preferable choice as there are less additional corrections needed, as well as providing a more stable long-term result after treatment. After the correction of the orbitas, the medial corners of the eyes are put more into a horizontal line.

- Nasal deformity correction: The correction of the broad nasal base is simultaneously done with the orbital hypertelorism repair. This is for good alignment of the eyes with the nose for the best aesthetic result. A bifid nose tip will only be treated at the age of 18, when the patient's skeleton has fully matured.

Because newborns can breathe only through their nose, the main goal of postnatal treatment is to establish a proper airway. Primary surgical treatment of FND can already be performed at the age of 6 months, but most surgeons wait for the children to reach the age of 6 to 8 years. This decision is made because then the neurocranium and orbits have developed to 90% of their eventual form. Furthermore, the dental placement in the jaw has been finalized around this age.