Hello dear customer, First of all, thank you for your interest. Our product is in a **fitted mold**, which means it has a cut that fits the body. While chest size is critical in these types of patterns, we cannot provide definitive information about whether the buttons will close completely or not for a 90 cm chest size, as everyone's body structure is different. Generally, for fitted patterns, some users may prefer one size larger for a more comfortable stance, but this entirely depends on personal use and preference. Since the manufacturer does not share detailed measurements of the model's chest/body, we cannot give a clearer direction. We kindly ask you to review the size chart on Trendyol and the customer reviews, they will be very helpful in your decision-making process.