Acessibilidade / Reportar erro

Sella landmark variability and its effect on the Angles SNA and SNB: a comparative study

Variabilidade do ponto Sela e seu efeito em ângulos SNA e SNB: um estudo comparativo

ABSTRACT

Objective:

To determine intra- and inter-observer precision in Sella (S), Nasion (N), point A and B identification. Additionally, to determine how it can interfere with angular measurements of SNA and SNB by orthodontists and dentomaxillofacial radiologists.

Methods:

Twenty digital lateral cephalometric radiographs were evaluated by five orthodontists and five dentomaxillofacial radiologists.

Results:

Differences in linear and angular measuremts were assessed. Intra- and inter-observer agreement was evaluated. Intra- and inter-observer reproducibility of the horizontal and vertical components of the S landmark identification (ICC: 0.75/0.90). Orthodontists tended to produce larger SNA (-0.18º), while SNB angle had a tendency to be smaller (0.55º). In general, SNA angle was smaller (DMFRs: -0.308º and orthodontists: -0.092º), and SNB presented with larger values (DMFR: 0.078º and orthodontists: -0.074º).

Conclusion:

Identification of the Sella landmark revealed a better agreement amongst dentomaxillofacial radiologists. Orthodontists, however, showed a larger variability in S identification and, consequently, the SNA and SNB angles drifted significantly.

Indexing terms:
Cephalometry; Comparative study; Orthodontics

Faculdade São Leopoldo Mandic R. José Rocha Junqueira, 13, 13045-755 Campinas/SP Brasil, Tel.: (55 19) 3211-3689 - Campinas - SP - Brazil
E-mail: contato@revistargo.com.br