Evaluation of mandibular length in subjects with Class I and Class II skeletal patterns using the cervical vertebrae maturation

Abstract

The aim of this study was to compare the mandibular size in boys and girls with Class I and Class II skeletal patterns, taking into consideration the bone maturation stage, as defined by the cervical vertebrae maturation. One hundred and sixty cephalometric radiographs were obtained from subjects (aged between 7 and 12 years) with Class I or Class II skeletal patterns, according to the ANB angle and WITS appraisal. The Class I sample consisted of 80 subjects (40 boys, 40 girls). The Class II sample also consisted of 80 subjects (40 boys, 40 girls). On a cross-sectional basis, mandibular length (Co-Gn) was compared between groups and genders. The between-stages changes were also evaluated, with the cervical vertebrae analysis used for establishing the bone maturation stages at CS2, CS3, CS4 and CS5. The results were statistically analyzed by the Kruskal-Wallis test. The mandibular length differed between skeletal patterns only at the earlier stages of development. In the Class I pattern, the mandibular lengths of boys were greater than those of girls at stages CS2, CS4 and CS5, whereas in the Class II pattern, the mandibular lengths of boys were greater than those of girls at stages CS2, CS3 and CS4. The present results indicate a sexual dimorphism in the mandibular length at almost all stages of bone maturation, in exception of the CS5 stage in Class II.

Comparison of lateral photographic and radiographic sagittal analysis in relation to Angle’s classification

“…This suggests that angle, rather than linear, measurements are better suited for comparison in conjunction with soft tissue analysis. Actual jaw size demonstrates size-associated dimorphism between genders [10,33], but not in terms of shape proportions. Another point to consider is that using angulation removes the need to standardize size.…”

“…Dieser Befund legt eine bessere Eignung von Winkel-als Streckenmessungen für Vergleiche im Zusammenhang mit Weichteilanalysen nahe. Die eigentlichen Kieferdimensionen zeigen einen größenasso-ziierten Dimorphismus zwischen den Geschlechtern [10,33] In the maxilla, the highest significant correlations we identified were between the soft tissue angle TrN' A' and the skeletal A to N perp (R=0.310) and SNA (R=0.421) measurements (p<0.001; Tab. 4).…”

Reliability, efficacy and reproducibility of the cervical vertebrae maturation index (CVMI)

“…However, this method requires an additional radiographic film, with more exposure to radiation outside of the craniofacial region. In a quest to avoid unnecessary exposure to radiation and to reduce redundant diagnostic material, some have correlated the morphological changes that occur in CV to mandibular growth (GENEROSO et al, 2010;DAMIAN et al, 2011), Angle malocclusions (VIEIRA et al, 2006;ARMOND et al, 2012), skeletal age (CALDAS et al, 2007;CALDAS et al, 2010;AGUIAR et al, 2013), and dental age (VIEIRA et al, 2009;RÓŻYŁO-KALINOWSKA et al, 2011;SACHAN et al, 2011;KOTHAVADE et al, 2012;MAYARÍ, 2012;VALIZADEH et al, 2013).…”

“…For proper staging, radiograph quality and knowledge of vertebral anatomy are essential. Indeed, Generoso et al (2010) suggested that intermediate stages might exist among the established CVMI stages, as some anatomical traits are not covered by the standard CVMI. Therefore, developing a more precise method would require including more stages or changing the assessment from visual-subjective into a more objective nature.…”

“…Chronological age is not a reliable parameter in determining an individual's growth potential as it is influenced by genetics, socioeconomical and hormonal factors (MARCELINO; TAVANO, 2005). From the standpoint of orthodontic diagnosis and treatment planning, skeletal maturation is a much more reliable base to support one's clinical decisions (GENEROSO et al, 2010).…”