Soft-tissue profile--fallacies of hard-tissue standards in treatment planning

The study was designed to test the efficacy of using a cephalometric dentoskeletal standard as a clinical tool to produce predictable and desirable facial esthetics. Thirty adolescent patients were randomly selected who, at the completion of treatment, had lower incisors positioned approximately 1.5 mm anterior to the A-pogonion plane. A normal sample of excellent faces (Indiana sample) was used for comparison. Both profile measurements of hard and soft tissues were made. The most striking observation was the large variation in the facial profiles even in cases successfully treated to a cephalometric dentoskeletal standard. The variation (2 standard deviations) of lip protrusion from the subnasale pogonion plane was 5 mm or a total of 10 mm. Similar variations were found in other soft-tissue measurements. The results suggest that any given dentoskeletal standard has questionable validity in producing either desirable esthetics or reproducible profiles following treatment.