Matthew Maddox, one of the longest-serving executives at Wynn Resorts, has replaced Steve Wynn as chief executive officer. Maddox, 42, joined Wynn Resorts in 2002, when Steve Wynn began rebuilding his casino empire from scratch. Maddox rose through the company’s ranks, working in Macau, then as chief financial officer and finally as president since November 2013. He was named chief executive officer by the company’s board late Tuesday after Wynn resigned amid sexual harassment allegations that threatened the company’s gaming licenses in the United States and Macau. “There is not a more trusted confidant than Maddox inside that company. He knows every inch of Wynn Resorts,’’ a Wall Street analyst said on the condition that he remain anonymous to maintain relations with the company. “However, he is rather young and hasn’t led a large group of people.’’ Maddox grew up in Mena, Arkansas, a town of 5,500 people just east of the Oklahoma border. Maddox graduated from Mena High School in 1994 at the top of his class and was voted “most likely to be remembered” by his roughly 120 classmates, according to the school’s yearbook. Maddox studied finance at Southern Methodist University in Dallas, Texas.