The Applicability of the Moyers, Tanaka-Johnston, and Gross-Hasund Analysis and a New Formula for the Vietnamese Population.

Aim: Our aim is to determine the applicability of other analyses and develop a new formula appropriate for the Vietnamese population.

Materials and methods: A cross-sectional descriptive analysis was conducted on a total of 120 dental arch samples (18-25 years old, 60 males, and 60 females) with <5 mm of tooth crowding, complete teeth on the dental arch, no missing teeth, and no fillings on the mesial or distal sides. Each study sample will be imprinted and measured using conventional as well as digital methods.

Result: There was a significant discrepancy between the overall mesiodistal width from canine to second premolar in the maxilla and mandibular measured with electronic calipers on the cast model and the values calculated by the Moyer, Tanaka - Johnston, Gross - Hasund formulae in the mandibular, and measured by digital scanning and results calculated by the Gross-Hasund formula for maxilla and mandibular and the Moyers, Tanaka-Johnston formula for mandibular. The values obtained were compared with those calculated using the Moyers, Tanaka-Johnston, and Gross-Hasund formulae for the mandibular. Additionally, measurements were taken by digital scanning, and the results were calculated using the Gross-Hasund formula for both the maxilla and mandibular, and the Moyers and Tanaka-Johnston formulae for the mandibular. When used to estimate space analysis in the Vietnamese population, the estimation formula for each gender had greater accuracy and reliability than other widely used methods.

Conclusions: As the central incisor and first molar are the first permanent teeth to erupt, the mesiodistal width may be readily measured. This new formula may be used to predict the width in the early stages of the mixed dentition.