Three-dimensional assessment of back symmetry in subjects with unilateral functional crossbite during the pre-pubertal growth phase: a controlled study.

BACKGROUND/OBJECTIVES: Since a high prevalence of back anomalies has been reported among subjects with crossbite, the aim was to assess the degree of back symmetry among subjects with (crossbite) and without (control) unilateral functional crossbite during the pre-pubertal growth phase. METHODS: A group of 70 subjects (36 boys, 34 girls; 6.8 ± 1.2 years) in the primary or mixed dentition phase were included. Clinical assessment of head posture, shoulder, scapula and hip height were performed with the subject standing, and differences between the left and right side greater than 5 mm recorded. Asymmetry of the scapula and trunk prominence greater than 8 mm was recorded along with the prominence of thoracic and lumbar paravertebral musculature during the forward-bending test. Back symmetry was assessed qualitatively and quantitatively on colour deviation maps of superimposed mirrored three-dimensional back scans at a tolerance level of 2 mm. RESULTS: No significant differences were observed between the groups regarding the frequency of clinically assessed back anomalies. The percentage of back symmetry was slightly lower in the crossbite than that in the control group (71.4 ± 13.3% and 79.2 ± 12.1%, respectively). A significant association (P < 0.05) was seen between scapula plane inclination (OR = 3.41) and scapula prominence inequalities (OR = 3.29) and unilateral functional crossbite, while hip height inequalities (OR = 0.94) were more frequent in the control group. No associations were detected between the side of crossbite and side of prominence of back parameters. LIMITATIONS: The use of different thresholds for clinical (5-8 mm) and three-dimensional (2 mm) symmetry assessment. CONCLUSIONS: Although some degree of back asymmetry was detected in the crossbite group during the pre-pubertal growth phase, this asymmetry does not appear to be clinically relevant.

A controlled study of the functional and morphological characteristics of malocclusion in prematurely born subjects with low birth weight.

BACKGROUND/OBJECTIVES: Prematurely born children show significant delay in many areas of physical development, including the orofacial structures. The aim of the present study was to evaluate the influence of premature birth on the prevalence of functional and morphological characteristics of malocclusion in the deciduous dentition phase, considering also confounding variables, such as type of feeding and oral habits. MATERIAL/METHODS: Through questionnaires and clinical examinations of 80 prematurely born subjects (42 females, 38 males, aged 24.46 ± 1.77 months; PBG) and 113 controls (50 females, 63 males, aged 25.42 ± 2.64 months; CG) in the deciduous dentition phase, data about feeding modalities, sucking habits, and functional and morphological characteristics of malocclusion were collected, and the two groups were compared for differences (chi-square test). Logistic regression analysis was used for risk assessment. RESULTS: The prevalence of functional and morphological characteristics was not significantly different (P > 0.05) in PBG compared with the CG, and premature birth was not a risk indicator for any characteristics of malocclusion. The main significant risk indicators for class II/1 malocclusion were dummy (OR = 3.13; P < 0.01) and thumb sucking (OR = 4.41; P < 0.05), while dummy sucking alone was a risk indicator for anterior open bite (OR = 12.19; P < 0.001). LIMITATIONS: In the present study, the PBG and CG were close in mean gestational age and birth weight, which might have influenced the results. CONCLUSIONS: Prevalence of malocclusion among prematurely born subjects is not significantly different compared with controls, and premature birth is not a risk indicator for any functional or morphological characteristics of malocclusion.