Dr. Feinstone's descent into madness, his obsession with oral hygiene, and his violent outbursts – while expanding upon the original plot and introducing new elements of horror. Brooke's infidelity adds a significant layer to Alan's psychological breakdown. His obsession with perfection extends beyond dental work to his personal life, and her betrayal shatters his carefully constructed image of a flawless existence. Opera, with its emphasis on beauty and emotion, is a stark contrast to the brutal reality of Alan's actions. It also provides a chilling visual metaphor for Alan's distorted perception of reality and his descent into madness.

Sarah, the teenage patient, adds a new dimension to Alan's predatory behavior. His interactions with Sarah highlight his disturbing fascination with youth and innocence, and her eventual escape and confrontation with him provide a sense of catharsis and a glimmer of hope. The revelation that Brooke has become his dentist in the asylum is a chilling and darkly humorous twist that underscores the cyclical nature of his madness and the enduring impact of his trauma.