TMJ Ankylosis is very easy to diagnose with the help of Clinical examination, and it is dependent on knowing the clinical features to differentiate True Ankylosis from False Ankylosis and also to differentiate between Unilateral and Bilateral ankylosis.
Here we are going to Differentiate between Unilateral and Bilateral TMJ Ankylosis and list out the Clinical features to help in diagnosing TMJ ankylosis.
Clinical Features of UNILATERAL TMJ Ankylosis:
- Facial Asymmmetry
- Deviation of the mandible and chin towards the affected side
- The chin is Receded with hypoplastic mandible on the affected side
- Roundness and Fullness of the face on the affected side
- The appearance of the flatness and elongation on the unaffected side
- The lower border of the mandible on the affected side has a concavity that ends in a well defined antegonial notch
- In unilateral ankylosis some amount of oral opening may be possible. Interincisal opening will vary depending on whether it is fibrous or bony ankylosis
- Cross bite may be seen
- Condylar movements are absent on the affected side
- Angles Class 2 Malocclusion on the affected side with unilateral posterior cross bite on the ipsilateral side is seen
Clinical Features of BILATERAL TMJ Ankylosis:
- Inability to open mouth progresses by gradual decrease in interincisal opening.
- Mandible is Symmetrical but Micrognathic
- “Bird Face” Deformity is seen with receding chin
- The Angle between Neck and Chin maybe reduced or completely absent in extreme cases
- Antegonial notch is well defined Bilaterally
- Class 2 malocclusion can be noticed
- Upper incissors are often protrusive with anterior open bite. Maxilla may be narrow
- Oral opening will be less than 5 mm or many times there is no oral opening
- Multiple carious teeth with bad periodontal health can be seen
- Severe malocclusion, crowding can be seen and many impacted teeth may be found on the X-rays