[Salah satu gejala TMD dapat berupa keterbatasan gerak mandibula yang antara lain dapat dilihat melalui besar pembukaan mulut. Telah terdapat penelitian tentang besar pembukaan mulut di negara lain, tetapi belum pernah dilakukan di Indonesia. Penelitian dilakukan untuk melihat hubungan besar pembukaan mulut dengan TMD di Indonesia. Penelitian menggunakan metode potong lintang pada 223 mahasiswa UI berusia 17-22 tahun. Subjek mengisi kuesioner Indeks Diagnostik-TMD dan diukur besar pembukaan mulutnya. Hasil uji t tidak berpasangan menunjukkan perbedaan bermakna pada rata-rata besar pembukaan mulut subjek TMD dan non-TMD (p=0,005). Ditemukan hubungan antara besar pembukaan mulut dengan Temporomandibular Disorders di Indonesia.;One of the symptoms of Temporomandibular Disorders (TMD) is limitation of mandibular movement that is reflected in mouth opening. Study of measurement of mouth opening has not been done in Indonesia. The aim of this study was to analyze the relationship between width of mouth opening and TMD in Indonesia. Cross-sectional study was performed towards 223 UI students aged 17-22. Firstly, subjects had to fill the TMD-Diagnostic Index questionnaire, then mouth opening was measured. Independent t-test showed significant difference between width of mouth opening in TMD and non-TMD subjects (p=0,005). There was a relationship between width of mouth opening and TMD in Indonesia, One of the symptoms of Temporomandibular Disorders (TMD) is limitation of mandibular movement that is reflected in mouth opening. Study of measurement of mouth opening has not been done in Indonesia. The aim of this study was to analyze the relationship between width of mouth opening and TMD in Indonesia. Cross-sectional study was performed towards 223 UI students aged 17-22. Firstly, subjects had to fill the TMD-Diagnostic Index questionnaire, then mouth opening was measured. Independent t-test showed significant difference between width of mouth opening in TMD and non-TMD subjects (p=0,005). There was a relationship between width of mouth opening and TMD in Indonesia]