A three-dimensional comparison of a morphometric and conventional cephalometric midsagittal planes for craniofacial asymmetry

Morphometric methods are used in biology to study object symmetry in living organisms and to determine the true plane of symmetry. The aim of this study was to determine if there are clinical differences between three-dimensional (3D) cephalometric midsagittal planes used to describe craniofacial asymmetry and a true symmetry plane derived from a morphometric method based on visible facial features. The sample consisted of 14 dry skulls (9 symmetric and 5 asymmetric) with metallic markers which were imaged with cone-beam computed tomography. An error study and statistical analysis were performed to validate the morphometric method. The morphometric and conventional cephalometric planes were constructed and compared. The 3D cephalometric planes constructed as perpendiculars to the Frankfort horizontal plane resembled the morphometric plane the most in both the symmetric and asymmetric groups with mean differences of less than 1.00 mm for most variables. However, the standard deviations were often large and clinically significant for these variables. There were clinically relevant differences (>1.00 mm) between the different 3D cephalometric midsagittal planes and the true plane of symmetry determined by the visible facial features. The difference between 3D cephalometric midsagittal planes and the true plane of symmetry determined by the visible facial features were clinically relevant. Care has to be taken using cephalometric midsagittal planes for diagnosis and treatment planning of craniofacial asymmetry as they might differ from the true plane of symmetry as determined by morphometrics

Evaluation of the Effects of Temporomandibular Joint Disc Displacement and Its Progression on Dentocraniofacial Morphology in Symptomatic Patients Using Posteroanterior Cephalometric Analysis

The aim of this study was to evaluate the effects of disc displacement (DD) and its progression on dentocraniofacial morphology in symptomatic patients, and to compare the results with asymptomatic volunteers. Female patients with DD, diagnosed with magnetic resonance imaging (MRI) and posteroanterior cephalometric analysis, were included in this study. Subjects were grouped as follows: control group with bilateral normal disc position (group 1, n=20), unilateral DD with reduction (group 2, n=17), bilateral DD with reduction (group 3, n=32), unilateral DD without reduction (group 4, n=16), and bilateral DD without reduction (group 5, n=19). Thirteen cephalometric variables were measured. A significant increase in the ANS (Anterior nasal spine)-Me (Menton)-MSP (Midsagittal plane) angle in unilateral DD groups and decreases in the Ag (Antegonial notch)-Me dimension on the affected side in all DD groups were observed. Also, the maximum values of the Me-MSP dimension and ANS-Me-MSP angle were observed in group 4. The results of this study showed that the deviation of the menton point toward the disc displacement side causes a mandibular asymmetry. It can be concluded from these results that the presence of DD in female patients affects facial morphology, and its progression makes the differences more significant and remarkable. These results emphasize the importance of early diagnosis and treatment in the management of DD

Comparison of cephalometric measurements from three radiological clinics Comparação de grandezas cefalométricas obtidas em três clínicas radiológicas

The orthodontic documentation carried out in radiological clinics is essential for diagnosis, planning and control of the orthodontic treatment. Amongst the diagnosis elements used are the cephalometric measurements, and errors can be incorporated as they are obtained. The objective of this work was to evaluate the values of some cephalometric measurements obtained in three radiological clinics using 30 lateral cephalometric radiographs of the head randomly chosen from the archives of the Department of Child Dentistry (Discipline of Orthodontics), School of Dentistry of Piracicaba, UNICAMP. These values were compared with the measurements obtained manually (control group) using variance analysis and Tukey’s and Friedman’s tests. Of the fourteen cephalometric measurements evaluated, the results demonstrated that only four of them presented statistically significant differences: IMPA, 1-NA, FMA, and H-nose. We concluded that although the majority of the mean cephalometric values did not present statistically significant differences, a great variability in the results was found when all the radiographic values were compared. This variability may influence the interpretation of the cephalometric measurements. Hence, we suggest that when the practitioner receives orthodontic documentation, he/she should redo the cephalometric analysis and compare the measurement values found with those presented to him. In addition, the practitioner should be prepared to use other elements for diagnosis, planning and control of the orthodontic treatment.<br>A documentação ortodôntica realizada em clínicas radiológicas é essencial para diagnóstico, planejamento e controle do tratamento ortodôntico. Dentre os elementos de diagnóstico utilizados estão as grandezas cefalométricas, e erros podem ser incorporados durante a obtenção das mesmas. O objetivo deste trabalho foi avaliar os valores de algumas grandezas cefalométricas obtidas em três clínicas radiológicas, utilizando-se 30 telerradiografias da cabeça em norma lateral, escolhidas ao acaso, do arquivo do Departamento de Clínica Infantil (Disciplina de Ortodontia) da Faculdade de Odontologia de Piracicaba - UNICAMP. Esses valores foram comparados com os das grandezas obtidas manualmente (grupo controle), utilizando-se a análise de variância e os testes de Tukey e Friedman. Os resultados demonstraram que das 14 medidas cefalométricas avaliadas, apenas 4 apresentaram diferenças estatisticamente significantes: IMPA, 1-NA, FMA, e H-nariz. Concluímos que apesar de a maioria dos valores médios das grandezas cefalométricas não apresentarem diferenças estatisticamente significantes, ao compararmos todos os valores obtidos em cada uma das radiografias, encontramos grande variabilidade nos resultados, o que pode interferir na interpretação das grandezas cefalométricas. Assim, os autores sugerem ao ortodontista, quando receber a documentação ortodôntica, realizar novamente as análises cefalométricas para comparar os valores das grandezas, e utilizar outros elementos para diagnóstico, planejamento e controle do tratamento ortodôntico