الفهرس 
Introduction.Only 14 pages are availabe for public view
Abstract
Temporomandibular joint (TMJ) Internal derangement is characterized by displacement of the intra-articular disc, The most Specific symptoms of TMDS are pain, restriction of mouth opening and joint sounds.it has always presented as therapeutic challenge to the maxillofacial surgeons. there are essentially two categories of TMDs treatment: conservative and surgical, Analgesic medication, thermotherapy or laser therapy, isometric exercises, rehabilitation exercises, bite splints, and massage of the chewing muscles are all examples of conservative treatments. Up to 25% of the entire population has internal derangement of TMJ are treated mainly with nonsurgical methods such as medications, physiotherapy and occlusal splints in the initial period.
Surgical procedures are frequently categorized as minimally invasive (including arthrocentesis and arthroscopy) or invasive (open) surgical procedures. Arthrocentesis is definitely applicable and highly effective in those patients who do not respond to conservative treatments. Murakami and colleagues, in 1987, introduced arthrocentesis of the TMJ, by reporting the recapture of the anteriorly displaced disk by mandibular manipulation after pumping and hydraulic pressure to the upper joint of the TMJ. In 1991, Nitzan and colleagues introduce a modified technique, which was dependent on the insertion of two needles within the upper joint space for lavage without direct visualization of the joint.
Washing out the upper joint space reduces jaw joint pain by diluting or flushing out the inflammatory mediators from the jaw joint and enhancing mandibular movements by removing intra-articular adhesions.
Imaging the osseous components of the TMJ using CBCT is less expensive and more readily available and easier in comparison to others as CT scan, US and MRI. The impact of new technology in the operating room setting must be carefully evaluated. A balance between benefits and effects is critical. Although a device that provides a surgeon with accurate information regarding anatomical localization might be expected to result in more effective surgery with improved clinical outcomes even if the surgeon lacked of required experience level.
Computer-assisted surgeries is a promising technology to decrease complication rates and operation time for MITMJS. The purpose of this study is to compare between conventional anatomical land marks needles insertion into TMJ space and that of computer guided land mark placement with a clear acrylic stent that made over a 3D printed model.
This study was conducted in 22 patients of 44 Total TMJs studied, who were referred to the TMD Clinic in the Oral and Maxillofacial Surgery department, Faculty of Dentistry, Ain Shams University with age range (l8 - 40) years. Diagnosis reached by the RDC/ TMD and confirmed with supplemental MRIs for all the patients.
Patients were divided randomly into two groups as following: a control group which injected intra-articular using conventional method based on anatomical landmark determined by alkan et al and a study group injected intra-articular using CBCT computer guided template planned in a manner inspired by earphone design to get tragus support.
Comparing the control group to the study group using guided template yielded no statistical significant difference regarding pain and maximum mouth opening both groups showed significant improvement in both parameters.
Regarding the number of needle punctures there are a statistically significance difference. In control group, the needle had to be repositioned to get proper outflow of lavage fluid. While the guide ensures the puncture takes place in the correct location and overall decrease the number of needle puncture attempts.
As well as, operation time also shows a statistically significance difference correlated that using patient specific guide required less operation time than conventional anatomical landmark detection.