USP Analysis
The USP analysis is the cephalometric standard developed at the University of São Paulo (Universidade de São Paulo, Brazil), first published by Professor Sebastião Interlandi in 1968. It draws on measurements from earlier analyses — including Downs, Tweed, Steiner, and Björk — combined into a single tracing protocol tailored to the diagnostic needs of the postgraduate orthodontics program at USP's School of Dentistry (FOUSP).
It has since become one of the most widely taught cephalometric standards in Brazilian orthodontics, valued for combining skeletal, dental, and soft-tissue assessment in one protocol, with an updated version (known as USP-2) later refined to better reflect modern surgical-orthodontic and CBCT-informed diagnostic practice.
What It Evaluates
The USP analysis evaluates the anteroposterior and vertical relationship of the jaws to the cranial base, the inclination and position of the upper and lower incisors relative to their supporting bone (dental compensation), and the soft-tissue facial profile — giving a broad, integrated picture of a patient's skeletal and dental pattern in a single tracing.
Key Measurements
- SNA / SNB / ANB — the same cranial-base-referenced angles used in most classic analyses, establishing the basic sagittal skeletal classification (Class I, II, or III).
- 1.NA and 1-NB — the angulation and linear position of the upper incisor to the NA line, and of the lower incisor relative to the NB line, describing how much the incisors are tipped or displaced to compensate for an underlying skeletal discrepancy.
- Interincisal angle — the angle between the long axes of the upper and lower incisors, reflecting the combined effect of both arches' dental compensation.
- FMA (Frankfort–Mandibular Plane Angle) — describes the vertical growth pattern, similar in purpose to the MMPA used in other analyses.
- Facial profile evaluation (soft tissue) — assessment of nasolabial and mentolabial relationships incorporated alongside the hard-tissue tracing, reflecting the analysis's original emphasis on correlating skeletal diagnosis with facial esthetics.
Learn more: Steiner's Analysis — 1-NA and 1-NB Incisor Position Measurements, SlideShare
Clinical Interpretation
As with other cephalometric standards, ANB establishes the sagittal skeletal pattern, while FMA establishes the vertical growth tendency (high values indicating a more open, hyperdivergent pattern; low values a more closed, hypodivergent pattern).
What distinguishes the USP analysis in practice is its emphasis on dental compensation: by comparing incisor position (1.NA / 1-NB and the interincisal angle) against the underlying skeletal classification, the clinician can judge how much the teeth have already "compensated" for a skeletal Class II or Class III discrepancy — information that is directly relevant to deciding between camouflage orthodontic treatment and combined orthodontic-surgical treatment. This integration of skeletal, dental, and soft-tissue findings in one protocol is why the analysis remains central to orthodontic diagnosis and treatment planning training in Brazil.