Maja Ovsenik

Posterior crossbite in the deciduous dentition period, its relation with sucking habits, irregular orofacial functions, and otolaryngological findings

INTRODUCTION The aim of this study was to assess unilateral posterior crossbite, sucking habits, orofacial functions, and otolaryngological findings in the deciduous dentition. These findings would allow us to establish a preventive program for posterior crossbite, based on interceptive treatment at an early stage of dental development. We would determine the predictive value for posterior crossbite development in correlation with the duration of sucking habits. METHODS Data were collected on 30 children (13 boys, 17 girls) with unilateral posterior crossbite (mean age, 5.5 years; range, 3.6-7.2 years) and 30 children (17 boys, 13 girls) without crossbite (mean age, 5.9 years; range, 5.4-6.7 years), randomly selected from a local kindergarten. Information about each subjects nutritive and nonnutritive sucking behaviors was collected through parent interviews and questionnaires. An orthodontist and an otolaryngologist clinically examined all the children. Study models were obtained from all children, and dental arch parameters including arch widths in the canine and second deciduous molar regions were measured directly from the models. The data were then compared between the posterior crossbite and the noncrossbite groups. RESULTS The results indicated correlations between prolonged pacifier sucking habit (P = 0.001), short frenulum linguae (P <0.001), smaller maxillary arch width (P <0.001), greater mandibular arch width (P <0.002), and unilateral posterior crossbite. A receiver operating characteristic curve was plotted for the pacifier sucking time. The borderline for the development of posterior crossbite suggested by the receiver operating characteristic curve was 18 months of pacifier sucking duration. The odds ratios between the crossbite and noncrossbite groups were 3.6 (CI = 0.97-13.4) for pacifier habit duration of 18 to 35 months and 21.9 (CI = 3.7-129.4) for pacifier suckers of more than 36 months. No significant correlation between enlarged adenoids and tonsils or impaired nasal breathing and the crossbite was found. CONCLUSIONS These results suggest that the duration of a pacifier habit and a short frenulum linguae are associated with posterior crossbite at the age of 4 or 5 years because of the low tongue posture in the mouth. Pediatricians and pedodontists should give precise recommendations for enhancing breast feeding and discontinuing pacifier habits at least until the child is 18 months of age. Further studies are also needed to determine more objectively the etiology of tongue posture, swallowing pattern, and the length of the frenulum linguae in children with posterior crossbite.

Use of 3-dimensional surface acquisition to study facial morphology in 5 populations

INTRODUCTION The aim of this study was to assess the use of 3-dimensional facial averages for determining morphologic differences from various population groups. METHODS We recruited 473 subjects from 5 populations. Three-dimensional images of the subjects were obtained in a reproducible and controlled environment with a commercially available stereo-photogrammetric camera capture system. Minolta VI-900 (Konica Minolta, Tokyo, Japan) and 3dMDface (3dMD LLC, Atlanta, Ga) systems were used. Each image was obtained as a facial mesh and orientated along a triangulated axis. All faces were overlaid, one on top of the other, and a complex mathematical algorithm was performed until average composite faces of 1 man and 1 woman were achieved for each subgroup. These average facial composites were superimposed based on a previously validated superimposition method, and the facial differences were quantified. RESULTS Distinct facial differences were observed among the groups. The linear differences between surface shells ranged from 0.37 to 1.00 mm for the male groups. The linear differences ranged from 0.28 and 0.87 mm for the women. The color histograms showed that the similarities in facial shells between the subgroups by sex ranged from 26.70% to 70.39% for men and 36.09% to 79.83% for women. The average linear distance from the signed color histograms for the male subgroups ranged from -6.30 to 4.44 mm. The female subgroups ranged from -6.32 to 4.25 mm. CONCLUSIONS Average faces can be efficiently and effectively created from a sample of 3-dimensional faces. Average faces can be used to compare differences in facial morphologies for various populations and sexes. Facial morphologic differences were greatest when totally different ethnic variations were compared. Facial morphologic similarities were present in comparable groups, but there were large variations in concentrated areas of the face.

Three-dimensional evaluation of early crossbite correction: a longitudinal study

The aim of this longitudinal study was to assess whether correction of unilateral posterior crossbite in the primary dentition results in improvement of facial symmetry and increase of palatal surface area and palatal volume. A group of 60 Caucasian children in the primary dentition, aged 5.3 ± 0.7 years, were collected at baseline. The group consisted of 30 children with a unilateral posterior crossbite with midline deviation of at least 2 mm (CB) and 30 without malocclusion (NCB). The CB group was treated using an acrylic plate expander. The childrens faces and dental casts were scanned using a three-dimensional laser scanning device. Non-parametric tests were used for data analysis to assess differences over the 30 months period of follow-up. The CB children had statistically significantly greater facial asymmetry in the lower part of the face (P < 0.05) and a significantly smaller palatal volume (P < 0.05) than the NCB children at baseline. There were no statistically significant differences between the two groups at 6, 12, 18, and 30 months follow-ups. Treatment of unilateral posterior crossbite in the primary dentition period resulted in an improvement of facial symmetry in the lower part of the face (P < 0.05) and increase of the palatal surface area and palatal volume (P < 0.001). At 30 months, relapse was observed in eight children (26.7 per cent). Treatment of unilateral posterior crossbite in the primary dentition improves facial symmetry and increases the palatal surface area and the palatal volume, though it creates normal conditions for normal occlusal development and skeletal growth.

Early crossbite correction: a three-dimensional evaluation

A crossbite (CB) occurs in approximately 4-23 per cent of young children and may lead to mandibular and facial asymmetry. Therefore, early intervention is often necessary to create conditions for normal occlusal and facial development. The aim of this study was to assess facial asymmetry and palatal volume (pre- and post-treatment) in two groups of children, one with a unilateral CB and the other with no crossbite (NCB). Thirty children with CB (13 males, 17 females, mean age 4.9 +/- 0.98 years) and 28 children with NCB (17 males, 11 females, mean age 5.3 +/- 0.36 years) were included in the study. Those with a CB were treated with an intra-oral expansion appliance. The faces and dental casts of the children were scanned using a three-dimensional (3D) laser scanning device at baseline (T0) and after six months (T1) of treatment. Students t-tests were used to assess differences between the two groups in facial symmetry and palatal volume over the 6 month period. The CB children had statistically significantly greater asymmetry of the face (P = 0.042), especially the lower third (P = 0.039), and a significantly smaller palatal volume (P = 0.045) than the NCB subjects at baseline. There were no statistically significant differences between the two groups at T1. Treatment of a CB in the primary dentition corrected the facial asymmetry, particularly the lower part of the face. The palatal volume of the CB children increased as a result of orthodontic intervention to similar levels exhibited by the NCB children.

Incorrect orofacial functions until 5 years of age and their association with posterior crossbite

INTRODUCTION In addition to heredity, sucking habits, impaired nasal breathing, and atypical swallowing patterns are considered important factors in the etiology of posterior crossbite. The purpose of this study was to assess irregular orofacial functions to determine their correlation with posterior crossbite. METHODS Two hundred forty-three children were examined at the ages 3, 4, and 5. Irregular orofacial functions and morphologic traits of malocclusion were clinically evaluated. The prevalence of posterior crossbite and the relationship with incorrect orofacial functions was determined. Data were analyzed by using the chi-square test and repeated measures analysis of variance (ANOVA). RESULTS Posterior crossbite at 5 years of age was found in 20% of the children. Half of the crossbite children had dummy sucking or were bottle-fed. Bottle feeding decreased during the observation years, but atypical swallowing, thumb sucking, and mouth breathing persisted. Mouth breathing and dummy sucking behavior were found to be statistically significantly different between the crossbite and noncrossbite groups of children. Atypical swallowing patterns increased in children with crossbite and decreased in those without crossbite. The difference was statistically significantly different (repeated measures ANOVA, P = 0.038). CONCLUSIONS Every clinical examination of children in the deciduous dentition with sucking habits should include assessment of orofacial functions, especially the swallowing pattern, which was found to be an important factor in the etiology for posterior crossbite development.

Three-dimensional ultrasound diagnostics of tongue posture in children with unilateral posterior crossbite

INTRODUCTION Incorrect tongue posture on the mouth floor is considered an important factor in the etiology of unilateral posterior crossbite. The aim of this study was to objectively assess tongue posture in children with unilateral posterior crossbite and those with normal deciduous dentition by using 3-dimensional (3D) ultrasonography. METHODS First, referential 3D ultrasound images for differently postured tongues were acquired and reconstructed in 10 adults. Second, 27 children with unilateral posterior crossbite (mean age, 5.4 ± 1 years) and 23 children with normal deciduous dentition (mean age, 6.2 ± 0.4 years) were examined by using the 3D ultrasound technique. The referential 3D ultrasound reconstructions were used for the assessment of tongue posture in each child. RESULTS The characteristic 3D reconstruction of the tongue postured on the palate displays distinctive convexity of the tongue dorsum, whereas, in the 3D reconstruction with the tongue postured on the mouth floor, the dorsum is characterized by a central groove and expressed concavity. Posture on the mouth floor was demonstrated by 81.5% of the children with unilateral posterior crossbite and by only 34.8% of those with normal deciduous dentition. The difference was statistically significant (Fisher exact test: P = 0.0012). CONCLUSIONS Three-dimensional ultrasonography enables objective assessment of tongue posture and could become in the future an important part of functional diagnostics before, during, and after orthodontic treatment.

Three-dimensional longitudinal evaluation of palatal vault changes in growing subjects

OBJECTIVE To evaluate palatal vault change in children and to assess the reliability of two palatal parameters in assessing growth modifications. SUBJECTS AND METHODS A group of 26 healthy white children aged 5.3 ± 0.3 years (15 boys, 11 girls) were randomly selected. Impressions of the upper dental arches were obtained at baseline and at 12, 18, and 30 months follow-up. Three-dimensional digital images of study casts were obtained using a laser scanning device. Palatal surface area and palatal volume were measured on the digital study casts at each time point. Effect size (ES) coefficients were calculated for both parameters as indices of diagnostic reliability in individual subjects when at least equal to 1.0. RESULTS Significant increases in palatal surface area and volume were seen over the observation period (P < .001). ES coefficients for palatal surface area were greater than those for palatal volume. However, even for the former parameter, only the value taken at 30 months was above the threshold. CONCLUSIONS Growth of the palatal vault was significant during the observation period, which coincides with primary and mixed dentition stages. Palatal surface area appears to be more reliable than palatal volume in assessment of growth modifications in individual subjects.

Overjet as a predictor of sagittal skeletal relationships

Skeletal relationships in the sagittal plane do not always correspond with dental relationships. The aim of this study was to determine in which type of malocclusion the correlation between overjet and skeletal sagittal parameters assessed by lateral cephalogram analysis is the highest. The extent to which overjet can predict skeletal relationships in the sagittal plane was also assessed. Eighty-three subjects fulfilled the inclusion criteria (40 males and 43 females, mean age 16.3 +/- 4.3 years). Overjet was measured on study casts and sagittal skeletal relationships were analysed on lateral cephalograms. ANB angle, Wits appraisal, and convexity at point A were determined. Mean values and standard deviations of measured parameters were calculated for Class I, Class II division 1, and Class III malocclusion subjects. Correlation between overjet measured on study casts and sagittal skeletal parameters measured on lateral cephalogram was calculated. Overjet as a predictor of skeletal relationships was assessed by means of linear regression analysis. A statistically significant positive correlation (P < 0.01) was found between the values of overjet and ANB (r = 0.690), overjet and Wits appraisal (r = 0.750), and overjet and convexity at point A (r = 0.608) when assessing the whole sample. When linear regression between overjet and cephalometric parameters was assessed separately in Class I, Class II division 1, and Class III malocclusion subjects, the percentage of variability was statistically significant in just four pairs. The findings show that overjet is a good predictor of sagittal relationship only in subjects with a Class II division 1 malocclusion.

Assessment of facial asymmetry in growing subjects with a three-dimensional laser scanning system

OBJECTIVES To evaluate facial asymmetry in growing subjects with no malocclusion on three-dimensional laser facial scans. SETTING AND SAMPLE POPULATION Twenty-seven healthy Caucasian children (15 boys and 12 girls, aged 5.4 ± 0.3 years) in the primary dentition without malocclusion were randomly selected from a local kindergarten in Slovenia. MATERIAL AND METHODS Surface facial images were obtained using a three-dimensional laser scanning system at baseline and at 18, 30, 42 and 54 months of follow-up. Facial asymmetry was assessed quantitatively by measuring the average distance between facial image and mirrored image. Further, the percentage of asymmetry was calculated as the percentage of image to mirrored image not coinciding within 0.5 mm. Qualitative assessment was performed on colour deviation maps by recording the predominant side of the face for the upper, middle and lower parts of the face separately. Nonparametric tests were used for data analysis. RESULTS No face was perfectly symmetric. The average distance between the mirrored images for the whole face ranged 0.22-0.85 mm and the percentage of asymmetry 7.8-66.9. There were no significant gender differences (p > 0.05), and no significant change was found over the observed period. The upper part of the face was the least asymmetric, while the lower and middle parts showed similar degrees of asymmetry. CONCLUSION Facial asymmetry is already present at an early developmental stage and does not show any tendency to increase or decrease with growth in the pre-pubertal period.

Novel method of 3-dimensional soft-tissue analysis for Class III patients

INTRODUCTION The aim of this study was to evaluate 3-dimensional facial shells by incorporating a population-specific average template with a group of Class III subjects preparing to have orthognathic surgery. METHODS The Class III group included 14 male (MCIII) and 15 female (FCIII) subjects. We used 43 male and 44 female Class I subjects to construct average male (AvM) and female (AvF) faces. Coordinates of 3 points on the facial templates of groups MCIII and FCIII and the templates AvM and AvF were compared. MCIII-AvM and FCIII-AvF superimpositions were evaluated for differences. RESULTS Vertical distances (sella to soft-tissue pogonion) were statistically significantly higher for the AvM (9.1%) and MCIII (10.1%) than for the AvF and FCIII, respectively (P < 0.05). The distances of soft-tissue pogonion in the horizontal x-axis were positive in 80% of the FCIII group and 85.7% of the MCIII group. The Class III subjects differed from the average face in the lower two thirds, but, in 50% (MCIII) and 60% (FCIII), they differed also in the upper facial third. CONCLUSIONS (1) The average and Class III Slovenian male morphologic face heights are statistically significantly higher than those of the female subjects. (2) The Slovenian Class III male and female subjects tend toward a left-sided chin deviation. (3) Differences between Class III patients and a normative data set were determined.