Transverse Ridge of Premolars and Oblique Ridge of Maxillary Molars are in Divine Golden Ratio.

Aims: In premolars and molars, transverse ridge (TR) and oblique ridge (OR) play major roles in providing strength and stability to the cusps in particular and tooth as a whole. Hence, they could be divided at the central groove or the transverse groove in a divine golden ratio.

Materials And Methods: Twenty pairs of maxillary and mandibular casts were retrieved from the Department of Orthodontics. The lengths of buccal triangular ridge (BTR), lingual triangular ridge (LTR) and TR of maxillary and mandibular first and second premolars were measured. Similarly, lengths of distal cuspal ridge of mesiopalatal cusp, triangular ridge of distobuccal cusp (DBTR) and OR of the maxillary first and second molars were measured using a brass wire and a Vernier caliper. The TR:BTR, BTR:LTR, OR:distal ridge of mesiopalatal cusp (MPDR), and MPDR:DBTR ratios were calculated to find out the possibility of golden ratio.

Results: Transverse ridges of the premolars and OR of the maxillary first and second molars were divided at the central groove in a divine golden ratio. The mean TR/BTR ratio for maxillary first premolar was 1.61 ± 0.007, whereas the mean BTR/LTR ratio was 1.63 ± 0.02. The mean TR/BTR ratio for maxillary second premolar was 1.61 ± 0.01, whereas the mean BTR/LTR ratio was 1.62 ± 0.04. The TR/BTR and BTR/LTR ratios for mandibular first premolar were 1.6 ± 0.008 and 1.64 ± 0.02, respectively. Similarly, the mean TR/BTR ratio for mandibular second premolar was 1.61 ± 0.01, whereas the mean BTR/LTR ratio was 1.63 ± 0.02.

Conclusion: The ORs of maxillary first molar ridge and TR of maxillary and mandibular premolars are divided into two parts at transverse and central grooves, respectively, in a divine ratio.

Clinical Relevance: The ORs of maxillary first molar ridge and TR of maxillary and mandibular premolars are divided into two parts at transverse and central grooves, respectively, in a divine ratio. This signifies the strength and stability of the occlusal table in the posterior teeth, as the golden ratio is the mark of functional excellence. Golden ratio should be taken into consideration while restoration or fabrication of the posterior teeth.