Anterior Open Bite | Christopher Lim Oral

Anterior Open Bite Developing over Several Years

This case demonstrates degenerative joint disease in a young patient who presented in the background of a connective tissue disorder. The symptoms started as a teenager and over years, the patient developed pain and dysfunction in both TMJs and gradual resorption of the condyles.

The treatment plan was completed over a four-year period. Initially starting with TMJ arthroscopy, re-arthroscopy, a course of orthodontics and customised TMJ replacements which addressed her functional deficits.

This is the original OPG X-ray above demonstrating slightly abnormal TMJ condyles. This was taken well before she sought surgical treatment. At that stage, the symptoms were mild and treated with an oral appliance. The third molars were still present which were removed later on. This also eliminated the third molars as a potential source of pain.

At a later stage and after some deliberation, the patient sought treatment with myself and opted to undergo a TMJ arthroscopy.

The arthroscopy seemed to give some temporary relief. It demonstrated an abundance of scar tissue and a perforation on one side. The pain and dysfunction occurred again and an arthroscopy was undertaken for a second time within 12 months.

The joints further deteriorated over a few years and the patient developed an anterior open bite. This is seen in the image below. It was decided to undergo a course of orthodontics and customised TMJ replacements in order to restore function in the first instance. Orthognathic surgery was also considered. However, due to the high chance of relapse, this was declined.

Above is a sagittal CT scan of the one of the patients temporomandibular joints. This was taken in the later phases of treatment and clearly demonstrates a flattened, degenerative joint with a classic bird's beak appearance.

The image below shows what is known as an anterior open bite that has developed due to her degenerative joint disease.

There is an obvious discrepancy at the front teeth where the patient cannot bite into anything substantial. This obviously a problem.

TMJ reconstruction with customised prosthesis usually requires a course of orthodontics to align and straighten the teeth before the final operation.

Once orthodontics is complete, TMJ fabrication can begin. Once again, a planning CT scan is taken and the customised prosthesis are fabricated according to the images and is designed such that the lower jaw is in a position that closed the open bite.

The image above demonstrates the final aspect of operative treatment with the customised prosthesis inserted. This is designed in order to close the anterior open bite and ensure that the front teeth meet. There is obviously no remodelling of the temporomandibular joints due to the prosthesis being made out of metal. The patient can out touch their front teeth together.

Below, is are images of the post-operative OPG with both the left and right temporomandibular joint replacements implanted and a photo of the patients post-operative occlusion. The front teeth meet and the anterior open bite is closed. The braces came off shortly thereafter. The pathological joint pain and dysfunction is addressed and normal function can return.