Pendahuluan: Kurva Spee adalah garis oklusi dalam arah sagital yang diperoleh dari insisal insisivus sentralis hingga distal marginal ridge gigi molar kedua dan berfungsi dalam pergerakan mandibula dan biomekanik mastikasi. Kurva Spee dipengaruhi oleh variasi pola wajah, perkembangan sistem neuromuskular, periode gigi-geligi dan waktu erupsi gigi. Penelitian ini bertujuan untuk mengetahui jarak titik-titik referensi, kedalaman kurva Spee berdasarkan jenis kelamin dan sisi mandibula, serta bentuk kurva Spee pada mahasiswa Fakultas Kedokteran Gigi Universitas Sumatera Utara (FKG USU) usia 18-24 tahun dengan oklusi kelas I Angle. Metode: Penelitian ini merupakan penelitian deskriptif analitik dengan pendekatan cross sectional dan dilakukan pada 30 mahasiswa. Pengukuran kurva Spee dilakukan pada model studi dengan menggunakan kaliper digital. Kedalaman kurva Spee dikategorikan menjadi bentuk datar, sedang, dan dalam. Hasil penelitian dianalisa dengan uji t-test. Hasil: Hasil penelitian ini menghasilkan nilai rerata jarak titik-titik referensi premolar satu, premolar dua, dan molar satu: 0,85±0,54mm, 1,35±0,52mm, dan 1,54±0,49mm. Berdasarkan jenis kelamin: laki-laki: 0,86±0,50mm, 1,37±0,46mm, dan 1,53±0,47mm; perempuan: 0,83±0,60mm, 1,32±0,60mm, dan 1,55±0,52mm. Berdasarkan sisi mandibula: kiri: 0,80±0,64mm, 1,37±0,65mm, dan 1,51±0,53mm; kanan: 0,89±0,56mm, 1,33±0,56mm, dan 1,57±0,54mm. Nilai rerata kedalaman kurva Spee adalah 1,24±0,48mm. Berdasarkan jenis kelamin: laki-laki: 1,25±0,41mm; perempuan: 1,23±0,55mm. Berdasarkan sisi mandibula: kiri: 1,22±0,55mm; kanan: 1,26±0,51mm. Bentuk kurva Spee yang diperoleh adalah bentuk datar (93,3%) dan sedang (6,7%). Simpulan: Tidak terdapat perbedaan titik-titik referensi dan kedalaman kurva Spee berdasarkan jenis kelamin dan sisi mandibula pada individu dengan oklusi kelas I Angle, dengan bentuk kurva Spee terbanyak adalah bentuk datar.Kata kunci: Kurva Spee, biomekanik mastikasi, oklusi kelas I Angle. ABSTRACTIntroduction: The curve of Spee is a line of occlusion in the sagittal direction obtained from the central incisor to the distal marginal ridge of the second molar and functions in the mandibular and biomechanical movement of mastication. Variations in facial patterns, development of the neuromuscular system, dentition period and the time of tooth eruption influence the curve of Spee. This study was aimed to determine the distance of reference points, and also the depth and shape of the curve of Spee based on sex and mandibular side in the students of Faculty of Dentistry University of North Sumatra aged 18-24-year-old with Angle class I occlusion. Methods: This research was a descriptive-analytic study with a cross-sectional approach, conducted towards 30 students. The measurement of the curve of Spee was carried out on the study model using digital callipers. The depths of the curve of Spee are categorised into flat, medium, and deep. The results of the study were tested with the t-test. Results: The results of this study obtained the mean distance of reference points of the first premolar, second premolar, and first molar which consecutively described as follows: 0.85 ± 0.54 mm, 1.35 ± 0.52 mm, and 1.54 ± 0.49 mm; Based on sex: male: 0.86 ± 0.50 mm, 1.37 ± 0.46 mm, and 1.53 ± 0.47 mm; female: 0.83 ± 0.60 mm, 1.32 ± 0.60 mm, and 1.55 ± 0.52 mm. Based on mandibular side: left: 0.80 ± 0.64 mm, 1.37 ± 0.65 mm, and 1.51 ± 0.53 mm; right: 0.89 ± 0.56 mm, 1.33 ± 0.56 mm, and 1.57 ± 0.54 mm. The mean value of the depth of the curve of Spee was 1.24 ± 0.48 mm. Based on sex: male: 1.25 ± 0.41 mm; female: 1.23 ± 0.55 mm. Based on mandibular side: left: 1.22 ± 0.55 mm; right: 1.26 ± 0.51 mm. The shape of the curve of Spee obtained was flat (93.3%) and moderate (6.7%). Conclusion: There was no differences in the reference points and depth of the curve of Spee based on sex and mandibular side of individuals with Angle class I occlusion, with the mostly found shape of the curve of Spee is flat.Keywords: Curve of Spee, mastication biomechanics, Angle class I occlusion.