Latar Belakang: Objektifitas rasio akar-mahkota gigi klinis dan konvergensi akar gigi. Tujuan: Menentukan rasio akar-mahkota gigi klinis dan tipe konvergensi akar gigi molar pertama yang menyebabkan trauma oklusi. Material dan Metode: Metode Lind (1972) dan metode baru untuk menentukan konvergensi akar gigi. Hasil: Rasio >1,51= baik; 1-≤1,50= cukup baik; 0,51-0,99= buruk; ≤0,50=sangat buruk. Ada hubungan antara gabungan rasio akar-mahkota gigi klinis dan konvergensi akar gigi dengan kegoyangan gigi (rs:0,302), lamina dura, (rs: 0,211), resesi gingiva bukal (rs: 0,245), kehilangan perlekatan (rs: 0,233). Kesimpulan: Ada hubungan antara rasio akar mahkota gigi yang tidak seimbang disertai konvergensi akar gigi dengan trauma oklusi.

---

Background: An objective assessment of clinical root-crown ratio and root convergence.

Objective: To determine the clinical root-crown ratio and root convergence type of first molar which cause trauma from occlusion.

Materials and Methods: Method of Lind (1972) and a new method to determine the root convergence.

Results: The ratio >1.51=good; 1-≤1.50= pretty good; 0.51-0.99= poor; ≤ 0.50= very bad. There is a relationship between the combined of clinical root-crown ratio and root convergence with tooth mobility (rs: 0.302), lamina dura, (rs: 0.211), buccal gingival recession (rs: 0.245), loss of attachment (rs: 0.233).

Conclusion: There is a relationship between the combine of clinical root-crown ratio and root convergence with trauma from occlusion.