Inverse Marcus-Gunn phenomenon is a rare condition in which the jaw moves away from the ear when the mouth is opened. It is the opposite of the normal Marcus-Gunn phenomenon, in which the jaw moves towards the ear when the mouth is opened. Inverse Marcus-Gunn phenomenon is usually caused by a malformation of the temporomandibular joint (TMJ).

The symptoms of Inverse Marcus-Gunn phenomenon include:

1. Delayed or absent palatal closure when the tongue is protruded.

2. Difficulty with speech production, including articulation errors and reduced intelligibility.

3. Difficulty with eating and drinking, including difficulty with sucking and swallowing.

4. Poor oral hygiene due to difficulty with tongue movement.

5. Poor facial growth and development.

6. Poor oral motor control.

7. Poor oral sensation.

8. Poor lip closure.

9. Poor lip and tongue coordination.

10. Poor jaw stability.

The causes of the Inverse Marcus-Gunn phenomenon are not fully understood. However, some possible causes include:

1. Abnormalities in the temporomandibular joint (TMJ)
2. Abnormalities in the muscles of mastication
3. Abnormalities in the trigeminal nerve
4. Abnormalities in the temporomandibular ligaments
5. Abnormalities in the joint capsule
6. Abnormalities in the teeth
7. Abnormalities in the jawbone
8. Abnormalities in the soft tissues of the mouth
9. Abnormalities in the jaw muscles
10. Abnormalities in the jaw joint

1. Orthodontic treatment: This involves the use of braces or other orthodontic appliances to correct the misalignment of the teeth and jaw.

2. Surgery: Surgery may be necessary to correct the underlying cause of the Inverse Marcus-Gunn phenomenon. This may involve the removal of excess tissue or the repositioning of the jaw.

3. Speech therapy: Speech therapy can help to improve the patient's speech and articulation.

4. Physical therapy: Physical therapy can help to improve the patient's range of motion and strength.

5. Medication: Medication may be prescribed to reduce inflammation and pain.

1. Cleft lip or palate
2. Abnormalities of the jaw
3. Abnormalities of the teeth
4. Abnormalities of the temporomandibular joint
5. Abnormalities of the tongue
6. Abnormalities of the lips
7. Abnormalities of the soft palate
8. Abnormalities of the hard palate
9. Abnormalities of the maxilla
10. Abnormalities of the mandible
11. Abnormalities of the facial muscles
12. Abnormalities of the temporomandibular ligaments
13. Abnormalities of the temporomandibular joint capsule
14. Abnormalities of the temporomandibular joint disc
15. Abnormalities of the temporomandibular joint cartilage
16. Abnormalities

There is no known cure for Inverse Marcus-Gunn phenomenon. However, there are medications that can help reduce the symptoms. These include anticonvulsants, muscle relaxants, and botulinum toxin injections. Additionally, physical therapy and speech therapy may be beneficial.