Shortened Mandible | Christopher Lim Oral

SHORTENED MANDIBLE DUE TO TMJ DEGENERATION

This case was a female in her 50s with decades of TMJ pain and dysfunction which gradually shortened her lower jaw due to bone resorption. Over many years, her dental bite/occlusion shifted backwards and she has severe limited oral opening(20mm) and could not eat due to TMJ pain and stiffness.

You can note her shortened lower jaw, and the diminished jaw joints along with an unstable bite with multiple missing teeth. The missing teeth and position of her lower jaw creates another problem in terms of optimal reconstruction as part of the aim is to restore her dental occlusion/bite so she can function well.

The initial step was to reduce pain and improve function in the short to medium term. This will temporarily improve quality of life for a short while. We undertook a short arthroscopic procedure which is both therapeutic and diagnostic. Below are the images:

Left arthroscopic image - complete destruction of the TMJ apparatus

Right arthroscopic image - also complete destruction with an obvious large perforated disc.

We planned for a bilateral TMJ replacement and aimed to correct a number of issues:

1) TMJ pain and dysfunction

2) A stable bite with the minimal loss of additional teeth

3) Restore her aesthetic profile

Because we were working with a significantly compromised dentition, certain financial and time limitations, we decided to take the most direct route and move her lower jaw forward with the use of her customised prosthesis. Although not the ideal, we can achieve the above goals in a reasonable time frame.

Original Jaw Position Planned Jaw Position

With the use of digital planning, we can virtually move her lower jaw forward and ensure that most of her front teeth were in contact. A good mandibular position was going to leave a small posterior open bite in some areas with the intention of utilising some restorative treatment after her reconstruction to give the patient a functioning bite.

RECONSTRUCTIVE PHASE

A bilateral TMJ prosthesis was fabricated in the above planned position. This was implanted and executed well as demonstrated by the following photographs and her teeth were restored with dentures. The option of implants were considered but the patient decided on the removable prosthodontic option. Below are the final photos and images. She is now several years out from treatment, there is no more pain and the patient can eat happily into a steak and an apple.