The temporomandibular joint the TMJ isthe joint between the lower jawbone the mandible and the temporal bone of the skull.The TMJ is responsible for jaw movement and is the most used joint in the body. The TMJis essentially the articulation between the condyle of the mandible and the mandibularfossa a socket in the temporal bone. The unique feature of the TMJ is the articulardisc a flexible and elastic cartilage that serves as a cushion between the two bone surfaces.The disc lacks nerve endings and blood vessels in its center and therefore is insensitiveto pain. Anteriorly it attaches to lateral pterygoid muscle a muscle of chewing. Posteriorlyit continues as retrodiscal tissue fully supplied
with blood vessels and nerves.The mandible is the only bone that moves when the mouth opens. The first 20 mm opening involvesonly a rotational movement of the condyle within the socket. For the mouth to open wider,the condyle and the disc have to move out of the socket, forward and down the articulareminence, a convex bone surface located anteriorly to the socket . This movement is called translation. The most common disorder of the TMJ is disc displacement, and in most of the cases, thedisc is dislocated anteriorly. As the disc moves forward, the retrodiscal tissue is pulledin between the two bones.
This can be very painful as this tissue is fully vascular andinnervated, unlike the disc. The forward dislocated disc forms an obstacle for the condyle movement when the mouth isopening. In order to fully open the jaw, the condyle has to jump over the back end of thedisc and onto its center. This produces a clicking or popping sound. Upon closing, thecondyle slides back out of the disc hence another quot;clickquot; or quot;popquot;. This condition iscalled disc displacement with reduction . In later stage of disc dislocation, the condylestays behind the disc all the time, unable to get back onto the disc, the clicking sounddisappeared but mouth opening is limited.
This is usually the most symptomatic stage the jaw is said to be quot;lockedquot; as it is unable to open wide. At this stage the conditionis called disc displacement without reduction Fortunately, in majority of the cases, thecondition resolves by itself after some time. This is thanks to a process called naturaladaptation of the retrodiscal tissue, which after a while becomes scar tissue and canfunctionally replace the disc. In fact, it becomes so similar to the disc that it iscalled a pseudodisc.
TMJ Surgery with Costochondral Graft in Bangladesh By Abdullah Al Masud
Assalamu Alaikum! I am Abdullah Al Masud, .Maxillofacial Surgeon.Asst Professor,Dhaka Dental College . Today I am gonna talk to you about a Surgery of Temporo Mandibular Joint ANKYLOSIS Facial Joint allows us to open our mouth during eating food or speaking. Have you ever seen people who can’t even open their mouth? .the girl we can see on the screen, is being asked to open her mouth. .but she can’t. She has a very little jaw movement.
Her TM joint is fused on one side of the face. .and the other side is normal. This condition can develop if a child fell down during playing. A child will play at home or school, its totally natural. If a child gets hit on hisher jaw during playing, .It can cause internal bleeding on the facial joint. After that, it gets locked gradually. So, the guardians should take good care of their child if they get hurt.
.and if they notice gradual reduction in mouth opening, they should consult a . Regular exercise of joint can reduce the chance of developing Lock Jaw. So, We are gonna start the operation. Usually we expose the joint on the front side of the ear. We can see the exposed area, where condyle of the mandible got fused completely with the joint. We will now resect that fused bone with bur. .and create a gap between them, which is called gap arthroplasty. The fused bone is being resected separated completely.
.with the help of bur Osteotome. We are separating it from the surrounding soft tissue with the help of periosteal elevator. Now We can see the resected part of the bone which got fused with the TM joint just after the resection, the mouth opening of this girl has increased immensely. .Which is measured as 40 mm or 4 cm. Usually 35 mm mouth opening atleast is considered as normal. Now its being exercised now with fergusson mouth gag.