Abstract :Background Intra-articular condition leading to disruption of the normal relationship of the articular disc to that of the articular eminence as well as the condyle is the main feature of internal derangement of the Temporomandibular joint . It may be seen during rest as well as during function . The chief complaints are of pain and limited mouth opening . Arthroscopy and arthrocentesis are the main types of treatments performed in order to treat internal derangements .Materials and MethodsThe study was designed as a retrospective study. A total of 22 patient records who had undergone arthrocentesis treatment were acquired by analysing the records of 86000 patients treated between June 2019 to March 2020 . Pearson correlation test was done to analyse the difference between the pre operative and postoperative mouth opening . The correlation between age and gender of the patient with the pre and the postoperative mouth opening was done using chi square test . SPSS version 20 software was used to carry out the statistics . ResultsThe mean and standard deviation values for pre and postoperative mouth opening were 30.98 ± 7.613 and 32.32 ± 7.134 respectively . After comparing the pre and postoperative mouth opening using Pearson’s correlation test a statistically significant result was obtained . P value obtained after Pearson's correlation test was 0.015 . Additionally no significant difference was found after correlating age and gender with the pre and the postoperative mouth opening after applying Chi square test . P values were 0.197 and 0.436 when age was correlated with pre and postoperative mouth opening . P values for gender when correlated with pre and postoperative mouth opening were 0.445 and 0.470 respectively .Conclusion : Within the limitation of the study it can be concluded that there was a significant difference in the mouth opening after arthrocentesis procedure . There was no significant relation between the pre and the postoperative mouth opening with the age and the gender of the patient .