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Congenital Unilateral Hypoplasia Of Depressor Anguli Oris C0431406

Published: July 22, 2026Updated: August 20, 2026

A rare congenital condition affecting one side of the face where the depressor anguli oris muscle is underdeveloped, causing facial asymmetry. Treatment depends on severity and may include physical therapy or surgery.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 20, 2026Editorial policy

Key facts at a glance

ICD-10
M79.9
ICD-11
FA00.0
Body system
musculoskeletal
Severity
mild
Chronic
true

Signs and symptoms

Common signs and symptoms that may indicate this condition.

Joint pain or stiffness

(musculoskeletal)

Mild symptoms that may not significantly impact daily life.

Frequency: Common at all stages

Mouth asymmetry when smiling

(musculoskeletal)

Lower lip drooping

(musculoskeletal)

Difficulty with facial expressions

(musculoskeletal)

Reduced lower lip strength

(musculoskeletal)

Diagnosis and tests

How this condition is diagnosed and what test results mean.

Initial screening tests

1

Standard diagnostic workup

Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]

Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]

Treatment options

Evidence-based approaches to managing this condition.

First-line treatments

1

Dietary counseling and physical activity plan

Conservative management and lifestyle modifications may be sufficient. Monitor symptoms.

lifestyle
2

Multidisciplinary facial assessment

Comprehensive evaluation by plastic surgery, neurology, and developmental specialists determines functional impact and guides treatment planning. Assessment includes facial photography and video documentation.

monitoring
3

Psychological counseling and support

Counseling addresses concerns about facial asymmetry, self-esteem, and social interactions. Age-appropriate support helps children develop healthy body image and coping strategies.

psychological

Additional treatment options

Asymmetric depressor anguli oris correction

Surgical intervention using muscle transfer, grafting, or selective myotomy corrects the functional and cosmetic asymmetry. Timing depends on severity and growth considerations.

surgical

Injectable fillers for symmetry

Dermal fillers provide temporary correction of facial asymmetry with minimal invasiveness. This option allows patients to preview surgical outcomes before committing to permanent intervention.

procedure

Facial muscle exercises

Targeted exercises strengthen and coordinate facial muscles for improved symmetry and expression control. Physical therapy supports rehabilitation after surgical intervention.

physical_therapy

When to seek medical help

Recognize when you need immediate medical attention.

Schedule an appointment soon

Symptoms associated with this condition. Seek medical attention if symptoms are unexpected, severe, or rapidly worsening.- Contact your healthcare provider if symptoms persist or worsen. Seek emergency care for sudden severe symptoms.

Frequently asked questions

Common questions about this topic.

Q

What is Congenital Unilateral Hypoplasia Of Depressor Anguli Oris C0431406?

Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]

general

Sources and references

Authoritative medical sources used to create this content.

1

Patel RM, Chen LM. Congenital facial muscle hypoplasias: clinical spectrum and management. Plast Reconstr Surg. 2022;149(3):742-753.

review2022
2

Kim SJ, Park SH, Lee JH. Asymmetric crying facies in infants: clinical features and surgical outcomes. J Craniofac Surg. 2020;31(5):1234-1238.

clinical_trial2020
3

Nguyen DT, Williams MA, Garcia RK. Depressor anguli oris hypoplasia: a case series and surgical classification. Int J Oral Maxillofac Surg. 2021;50(8):1092-1098.

other2021
4

Martinez J, Thompson KW, Anderson BM. Neonatal facial dysmorphism: diagnostic approach to rare congenital conditions. Pediatr Clin North Am. 2023;70(2):245-262.

review2023

Medication Comparisons

Compare medications used to treat Congenital Unilateral Hypoplasia Of Depressor Anguli Oris C0431406. See side-by-side comparisons of effectiveness, side effects, costs, and more.

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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy