Natalie, Dr. Do's Dental Assistant pops her head in to address a discoloration in her mouth that has concerned her for years. Fearing it may be cancer, she confides in her boss, and both decide it's time to address it head on. Heidi visits Dr. Gaff and is greeted by her mom Lindsay, Dr. Gaff's Dental Assistant. At only 15 years old, Lindsay's lip tie has propelled her into gum recession, and she is embarrassed by her smile.