Asymmetric crying facies

Overview

Asymmetric Crying Facies (ACF) is a congenital condition where one corner of an infant’s mouth does not move downward when the baby cries, resulting in facial asymmetry. This occurs due to the underdevelopment (hypoplasia) or absence (agenesis) of the depressor anguli oris muscle on one side of the lower lip. While often isolated and benign, ACF may sometimes be associated with other congenital anomalies, particularly involving the heart and head-neck region.

The asymmetry is typically most noticeable during crying or grimacing, and less obvious at rest.

Causes

ACF is caused by unilateral hypoplasia or absence of the depressor anguli oris muscle, which normally pulls the corner of the mouth downward. This muscle abnormality is believed to result from a developmental defect during fetal growth.

While the majority of cases are sporadic, some familial cases have been reported, suggesting a possible autosomal dominant inheritance pattern in certain families. ACF can also be part of larger syndromes, such as:

• 22q11.2 deletion syndrome (DiGeorge syndrome)

• VACTERL association

• CHARGE syndrome

Symptoms

The hallmark sign of ACF is:

• Facial asymmetry during crying or smiling, where one side of the lower lip pulls down and the other does not

Other potential associated findings include:

• Microtia or ear anomalies

• Congenital heart defects (e.g., ventricular septal defect, tetralogy of Fallot)

• Thymic hypoplasia

• Renal anomalies

In isolated ACF, the baby is otherwise normal and development is unaffected.

Diagnosis

Diagnosis of Asymmetric Crying Facies is primarily clinical and often made at birth:

• Physical exam: Shows asymmetry of the mouth only during crying or active facial movement

• Facial ultrasound: May reveal absence or underdevelopment of the depressor anguli oris muscle

• Electromyography (EMG): Can help distinguish muscle hypoplasia from facial nerve palsy

• Evaluation for associated anomalies:

  • Echocardiogram (for congenital heart disease)

  • Renal ultrasound

  • Chromosomal microarray or genetic testing if syndromic features are present

Treatment

In most cases, especially when ACF is isolated, no treatment is required. Management options include:

Observation and Reassurance:

• Asymmetry may improve over time as facial muscles strengthen

• No impact on speech, feeding, or intelligence in isolated cases

Surgical Options (rare):

• Plastic or reconstructive surgery: May be considered in older children or adults for cosmetic reasons

• Muscle transfer procedures: Rarely needed unless asymmetry is severe or affects function

Management of Associated Conditions:

• Treatment depends on the presence and severity of any associated congenital anomalies

• Referral to cardiology, genetics, or ENT as needed

Prognosis

The prognosis of Asymmetric Crying Facies is generally excellent in isolated cases. Key points include:

• Normal growth and development

• No effect on feeding, speech, or neurological function

• Facial asymmetry becomes less noticeable with age in many children

However, if ACF is part of a syndrome or associated with internal anomalies, the overall prognosis depends on the nature and severity of those conditions. Early evaluation and multidisciplinary care are crucial in such cases.