Mo. Rev. Stat. § 287.655

Any claim before the division may be dismissed for failure to prosecute in accordance with rules and regulations promulgated by the commission. Such notice shall be made in a manner determined by the division, except that for the employee such notice shall be by certified or registered mail unless the employee to whom notice is directed is represented by counsel and counsel is also given such notice. To dismiss a claim the administrative law judge shall enter an order of dismissal which shall be deemed an award and subject to review and appeal in the same manner as provided for other awards in this chapter.