Aim: This study was conducted to compare Computed guided arthrocentesis 
with conventional arthrocentesis followed by I-PRF prolotherapy in the treatment of 
TMJ internal derangement. Subjects and methods: the study was carried out on 20 
patients divided into two groups: Group I, patients underwent arthrocentesis followed 
by I-PRF injection using conventional TMJ injection technique with the aid of facial 
anatomical landmarks. Group II, patients underwent arthrocentesis followed by I-PRF 
injection using a CT-guided 3D printed surgical guide. Pain scores measured and MIO, 
preoperatively, immediately after the procedures, 1 week, 1 month, and 3 months. MRI 
was made 1 week and 3 months after the procedures. The number of attempts of needle 
insertions of 1st & 2nd needle (Right -Left) were assessed and the Time of operation and 
pain during the operation were assessed. Results: a significant decrease in pain during 
procedures, immediately post-operative, 1 week and 1 month post-operative, number 
of insertions and relocation of the needles in each joint, and time of the procedures in 
the guided arthrocentesis group compared to the conventional arthrocentesis group. 
On the other hand, there was no significant difference between both groups in MIO, 
preoperative pain after 3 months. Conclusion: Digital arthrocentesis and prolotherapy 
of TMJ showed superiority and could replace the current conventional and prolotherapy 
types. Intra-articular PRF injection after arthrocentesis is an effective treatment method 
for the pain relief of TMJ internal derangements