Need for orthognathic surgery in cleft patients from Northern Finland

OBJECTIVE

Northern Finland has a unique distribution of clefts compared to the rest of Europe and Finland. This may reflect the need for orthognathic surgery among Northern Finland's patient pool. The aim of this study was to compare previously operated patients aged 18 years or older with cleft lip, cleft lip and alveolus, cleft lip and palate, cleft palate and to evaluate the need for orthognathic surgery in order to achieve a stable and functional occlusion.  Materials and methods: The study group consisted of all 18-years-old cleft patients treated in the Oulu Cleft Center. The total amount of patients was 110. The patients were compared retrospectively using patients' hospital records. The majority of patients did not have any cleft-associated syndrome. The need for maxillary or bimaxillary orthognathic or corrective-jaw surgery was evaluated by the Oulu Cleft Team. A descriptive and statistical analysis was used to determine the need for orthognathic surgery according to sex and cleft type.

RESULTS

There were nineteen patients of the total of 110 patients who met the criteria requiring corrective-jaw surgery (17,3%). In total 12 males (25,0%) and 7 females (11,3%) were evaluated for the need of orthognathic surgery. Sixteen of the 19 patients had palatal involvement of the cleft.

CONCLUSIONS

The need for orthognathic surgery was greater in the cleft lip palate and cleft palate patient groups compared to cleft lip alveolus or cleft lip groups. This study also found that males from Northern Finland need surgery more often than females.

A longitudinal study of facial asymmetry in a normal birth cohort up to 6 years of age and the predisposing factors

OBJECTIVES

This prospective, population-based cohort study aimed to investigate the development of facial asymmetry up to 6 years of age using a three-dimensional (3D) soft tissue imaging method in a normal population. In addition, the study sought to identify potential predisposing factors to facial asymmetry.

METHODS

A total of 102 newborns were enrolled in the study at birth. 3D stereophotogrammetric images of the head and face were analysed at the ages of 12 months (T1), 3 years (T2), and 6 years (T3). The surface-based analysis involved the calculation of the average distance (mm) and the symmetry percentage (%) between the original and mirrored surfaces. For landmark-based analysis, the distance of facial landmarks to the facial midline was examined.

RESULTS

The final analysis included 70 (68.6%) subjects. Surface-based analysis showed a significant improvement of facial symmetry from T1 to T3 in all facial areas. Landmark-based analysis showed that upper facial landmarks were located, on average, slightly on the left and lower facial landmarks slightly on the right in relation to the facial midline (P < 0.001).

LIMITATIONS

The size of the study population was limited. Facial posture may affect the reliability of the results, especially in younger children.

CONCLUSION

Facial asymmetry is detectable in early childhood and tends to reduce with age in young children. The lower face deviates slightly to the right, and the upper face to the left in relation to the facial midline. Possible predisposing factors for facial asymmetry at the age of 6 years include deformational plagiocephaly, sleeping position, and previous facial asymmetry.

Facial asymmetry and chewing sides in twins

OBJECTIVE

To resolve how the preferred chewing side (PCS) affects facial asymmetry in twins, whether there are differences between monozygotic (MZ) and dizygotic (DZ) twins, and whether the twins with PCS have more asymmetric faces compared to symmetrically chewing twins.

MATERIAL AND METHODS

The study included 106 Lithuanian twin pairs of the same sex, 59 MZ and 47 DZ pairs. The data were analysed from facial 3D images and manually added landmarks. 3D images were analysed by Rapidform2006 software and statistical analyses were done by using the R software environment version 4.1.0.

RESULTS

The contralateral effect of PCS and larger chin side was dominant among right and non-right side chewing twins. Being female increased the whole face symmetry.

CONCLUSION

The volume of the chin becomes larger on the side opposite to the twins' habitual chewing side. As the results are quite similar in both twin types, functional factors are more prominent than heredity.

Dental fear among adolescents with cleft

BACKGROUND

Dental fear is a prevalent phenomenon among children and adolescents globally.

AIM

To investigate dental fear among 18-year-olds with cleft lip and/or palate (CLP) at their final follow-up cleft clinic visit, and to evaluate the association between dental fear and OHRQoL.

DESIGN

This cross-sectional study included the cohort of children with CLP treated at the Oulu University Hospital Cleft Lip and Palate Center, in northern Finland since 1995. A total of 62 of 64 individuals participated in this study. The validated Finnish version of the Oral Health Impact Profile (OHIP-14) was used to assess OHRQoL. Dental fear was studied using the validated Modified Dental Anxiety Scale (MDAS) and cognitive vulnerability model (CVM).

RESULTS

Almost two fifths of the participants reported moderate dental fear. Participants with cleft including lip and participants reporting impact on OHRQoL reported higher mean MDAS scores. In an unadjusted model, adolescents with cleft including lip had risk for higher dental MDAS scores compared with the ones with cleft including only palate.

CONCLUSIONS

Dental fear is common among adolescents with CLP, specifically among those with clefts involving the lip. OHRQoL and dental fear seem to be associated.

Maxillary Arch Dimensions in 6-Year-Old Cleft Children in Northern Finland: A Cross-Sectional Study

The aim was to cross-sectionally examine the maxillary arch dimensions in 6-year-old children with cleft lip and/or palate and to compare them with the initial cleft sizes among patients with cleft palate. The study included 89 patients with clefts treated at the Oulu University Hospital. The subjects were divided into three groups: cleft palate, cleft lip, and cleft lip and palate. Study casts were scanned, and the maxillary arch dimensions were examined using a 3D program (3Shape Orthoanalyzer, Copenhagen, Denmark). The statistical methods Student's t-test and one-way ANOVA were used to compare the means (SD) between the groups. Spearman's correlation coefficient was used to determine the correlation between cleft severity and maxillary dimensions. A significant difference was found between different initial cleft sizes in terms of distance between the second deciduous molar and the first incisor on the right side. The intermolar width showed a negative correlation with the initial cleft size. The dimensions were shorter for clefts affecting the palate and largest for clefts affecting only the lip. Larger clefts resulted in a shorter maxilla on the right side. Many dimensions became shorter when the initial cleft was larger. Clefts of the palate resulted in smaller maxillas.

An exploration of adolescent facial shape changes with age via multilevel partial least squares regression

BACKGROUND AND OBJECTIVES

Multilevel statistical models represent the existence of hierarchies or clustering within populations of subjects (or shapes in this work). This is a distinct advantage over single-level methods that do not. Multilevel partial-least squares regression (mPLSR) is used here to study facial shape changes with age during adolescence in Welsh and Finnish samples comprising males and females.

METHODS

3D facial images were obtained for Welsh and Finnish male and female subjects at multiple ages from 12 to 17 years old. 1000 3D points were defined regularly for each shape by using "meshmonk" software. A three-level model was used here, including level 1 (sex/ethnicity); level 2, all "subject" variations excluding sex, ethnicity, and age; and level 3, age. The mathematical formalism of mPLSR is given in an Appendix.

RESULTS

Differences in facial shape between the ages of 12 and 17 predicted by mPLSR agree well with previous results of multilevel principal components analysis (mPCA); buccal fat is reduced with increasing age and features such as the nose, brow, and chin become larger and more distinct. Differences due to ethnicity and sex are also observed. Plausible simulated faces are predicted from the model for different ages, sexes and ethnicities. Our models provide good representations of the shape data by consideration of appropriate measures of model fit (RMSE and R2).

CONCLUSIONS

Repeat measures in our dataset for the same subject at different ages can only be modelled indirectly at the lowest level of the model at discrete ages via mPCA. By contrast, mPLSR models age explicitly as a continuous covariate, which is a strong advantage of mPLSR over mPCA. These investigations demonstrate that multivariate multilevel methods such as mPLSR can be used to describe such age-related changes for dense 3D point data. mPLSR might be of much use in future for the prediction of facial shapes for missing persons at specific ages or for simulating shapes for syndromes that affect facial shape in new subject populations.

Exploring the midline soft tissue surface changes from 12 to 15 years of age in three distinct country population cohorts

INTRODUCTION

Several studies have highlighted differences in the facial features in a White European population. Genetics appear to have a major influence on normal facial variation, and environmental factors are likely to have minor influences on face shape directly or through epigenetic mechanisms.

AIM

The aim of this longitudinal cohort study is to determine the rate of change in midline facial landmarks in three distinct homogenous population groups (Finnish, Latvian, and Welsh) from 12.8 to 15.3 years of age. This age range covers the pubertal growth period for the majority of boys and girls.

METHODS

A cohort of children aged 12 were monitored for facial growth in three countries [Finland (n = 60), Latvia (n = 107), and Wales (n = 96)]. Three-dimensional facial surface images were acquired (using either laser or photogrammetric methods) at regular intervals (6-12 months) for 4 years. Ethical approval was granted in each country. Nine midline landmarks were identified and the relative spatial positions of these surface landmarks were measured relative to the mid-endocanthion (men) over a 4-year period.

RESULTS

This study reports the children who attended 95 per cent of all scanning sessions (Finland 48 out of 60; Latvia 104 out of 107; Wales 50 out of 96). Considerable facial variation is seen for all countries and sexes. There are clear patterns of growth that show different magnitudes at different age groups for the different country groups, sexes, and facial parameters. The greatest single yearly growth rate (5.4 mm) was seen for Welsh males for men-pogonion distance at 13.6 years of age. Males exhibit greater rates of growth compared to females. These variations in magnitude and timings are likely to be influenced by genetic ancestry as a result of population migration.

CONCLUSION

The midline points are a simple and valid method to assess the relative spatial positions of facial surface landmarks. This study confirms previous reports on the subtle differences in facial shapes and sizes of male and female children in different populations and also highlights the magnitudes and timings of growth for various midline landmark distances to the men point.

Oral health-related quality of life among young adults with cleft in northern Finland

Objectives

This study aimed to examine Oral Health‐related Quality of Life (OHRQoL) among patients with cleft lip with or without palate (CLP) at their final scheduled follow‐up visit at the age of 18 years. Another aim was to investigate the motivation to attend multiple follow‐up appointments and the satisfaction with care given by the cleft team using inductive qualitative analysis.

Methods

This cross‐sectional study was conducted among the cohort of children born with CLP who had undergone treatment at the Oulu University Hospital Cleft Lip and Palate Centre, in northern Finland since 1995. OHRQoL was assessed using the validated Finnish version of the short form of the Oral Health Impact Profile (OHIP‐14). In addition to the OHIP‐14, two open‐ended questions were also included. These questions investigated the experience of each participant concerning their motivation to attend the Oulu University Hospital Cleft Lip and Palate Centre to receive complex treatments, and their satisfaction with care provided by the cleft team. Results were presented as proportions, means, and SD. Inductive content analysis method was performed for analysis of the open‐ended questions.

Results

A total of 63 patients with CLP participated in this study. More than half of the participants had cleft palate. More than half of the participants reported an impact on OHRQoL (OHIP‐14 score ≥ 3). All the participants with bilateral cleft lip and palate, three fourths of the participants with unilateral cleft lip and palate, and half of the participants with cleft palate reported impact on OHRQoL. Inductive content analysis showed that one fourth of the participants reported a good outcome as a motivation to attend cleft center despite of complex procedures. All the participants reported their appreciation of the cleft team.

Conclusions

Despite the comprehensive treatment received by the patients born with a CLP, they still experienced lower OHRQoL, especially physical pain and psychological discomfort were more pronounced. However, good outcome, support, and oral health care being a normal routine were the motivating factors to attend a long and demanding oral health care regimen.

Multilevel principal components analysis of three-dimensional facial growth in adolescents

BACKGROUND AND OBJECTIVES

The study of age-related facial shape changes across different populations and sexes requires new multivariate tools to disentangle different sources of variations present in 3D facial images. Here we wish to use a multivariate technique called multilevel principal components analysis (mPCA) to study three-dimensional facial growth in adolescents.

METHODS

These facial shapes were captured for Welsh and Finnish subjects (both male and female) at multiple ages from 12 to 17 years old (i.e., repeated-measures data). 1000 "dense" 3D points were defined regularly for each shape by using a deformable template via "meshmonk" software. A three-level model was used here, namely: level 1 (sex/ethnicity); level 2, all "subject" variations excluding sex, ethnicity, and age; and level 3, age. The technicalities underpinning the mPCA method are presented in Appendices.

RESULTS

Eigenvalues via mPCA predicted that: level 1 (ethnicity/sex) contained 7.9% of variation; level 2 contained 71.5%; and level 3 (age) contained 20.6%. The results for the eigenvalues via mPCA followed a similar pattern to those results of single-level PCA. Results for modes of variation made sense, where effects due to ethnicity, sex, and age were reflected in modes at appropriate levels of the model. Standardised scores at level 1 via mPCA showed much stronger differentiation between sex and ethnicity groups than results of single-level PCA. Results for standardised scores from both single-level PCA and mPCA at level 3 indicated that females had different average "trajectories" with respect to these scores than males, which suggests that facial shape matures in different ways for males and females. No strong evidence of differences in growth patterns between Finnish and Welsh subjects was observed.

CONCLUSIONS

mPCA results agree with existing research relating to the general process of facial changes in adolescents with respect to age quoted in the literature. They support previous evidence that suggests that males demonstrate larger changes and for a longer period of time compared to females, especially in the lower third of the face. These calculations are therefore an excellent initial test that multivariate multilevel methods such as mPCA can be used to describe such age-related changes for "dense" 3D point data.

Plagiocephaly after Neonatal Developmental Dysplasia of the Hip at School Age

Developmental dysplasia of the hip (DDH) may require early abduction treatment with infants sleeping on their back for the first few months of life. As sleeping on back is known to cause deformational plagiocephaly, we assessed school age children treated for dislocation or subluxation of the hip-joint in infancy. Plagiocephaly was analyzed by using cephalic index (CI) and oblique cranial length ratio (OCLR) as anthropometric measurements from 2D digital vertex view photographs. Six of the 58 (10.3%) DDH children and only one of the 62 (1.6%) control children had plagiocephaly (p = 0.041). Furthermore, cross bite was found in 14 (24.1%) of the DDH children and in 7 (10.3%) of the control children. Developmental dysplasia of the hip in infancy was associated with cranial asymmetries and malocclusions at school age. Preventive measures should be implemented.

A 3D Follow-Up Study of Cranial Asymmetry from Early Infancy to Toddler Age after Preterm versus Term Birth

Preterm infants are at higher risk for both symmetrical and asymmetrical head molding. This study involved 3D stereophotogrammetry to assess the cranial growth, molding, and incidence of deformational plagiocephaly (DP) in preterm children compared to term born children. Thirty-four preterm infants and 34 term born controls were enrolled in this study from Oulu University Hospital, Finland. Three-dimensional head images were obtained at the age of 2–4 months (T1), 5–7 months (T2), 11–13 months (T3), and 2.5–3 years (T4) from the term equivalent age (TEA). There was no statistically significant difference in oblique cranial length ratio (OCLR), cephalic index (CI), or weighted asymmetry score (wAS) between the two groups. Occipital flattening, defined by flatness score (FS) was statistically significantly greater in the preterm group than in the term group at T1–T4 (p < 0.05). In both groups, OCLR improved gradually over time. There were no instances, in either group, of severe DP and no moderate DP after T2. Results indicate that DP affects preterm and full-term children almost equally during the first three years of life, and cranial asymmetry resolves at a similar rate in both preterm and term groups after three months of corrected age. Preterm infants present with more occipital flattening than full-term children.

Relations of laterality and chewing sidedness in twins

OBJECTIVES

To study, whether there are associations between chewing side preference and other lateralities, whether there is a genetic origin for preferred chewing side (PCS), relations to sex, birth order and orthodontic treatment.

MATERIALS AND METHODS

The study included 113 twin pairs, 57 pairs monozygotic, 47 pairs same sex dizygotic and 9 pairs of opposite sex. The lateralities of preferred chewing side, footedness and eyedness were assessed by functional tests and handedness was checked by asking.

RESULTS

Right-handed, -footed and -eyed as separated groups, and true-right sided (combined), were evenly distributed by preferred chewing side. By contrast, left-handed, -footed, -eyed and non-right sided used more left or both sides when chewing. Birth order affected preferred chewing side among monozygotic: the first-born twin was more likely to have the preferred chewing side on the non-right, whereas second-born twins used right side. Gender, zygosity and orthodontic treatment were not statistically significant factors.

LIMITATIONS

Examination of chewing sidedness could have been done in several different ways to provide a definite result. Sample size of opposite sex twins was very small.

CONCLUSIONS

Preferred chewing side generally seemed to follow the side where other lateralities occur; however, monozygotic twins seemed to be more receptive to it. True-right sided were more evenly distributed than non-right sided by the preferred chewing side.

3D follow-up study of facial asymmetry after developmental dysplasia of the hip

OBJECTIVES

To evaluate the change in facial asymmetry among subjects treated for developmental dysplasia of the hip (DDH) from childhood to adolescence.

SETTING AND SAMPLE POPULATION

A total of 39 adolescents (26 females and 13 males), born and treated for DDH during 1997-2001, participated in the first examination in 2007 (T1; at the age of 8.2) and in the follow-up in 2016 (T2; at the age of 16.6).

MATERIAL AND METHODS

In this longitudinal study, three-dimensional (3D) images were taken using a 3DMD face system based on a stereophotogrammetric method. Facial asymmetry was determined as the average distance (mm) calculated between the original and superimposed mirrored face and the symmetry percentage (%) calculated as the face area where the distance between the original face and the mirrored surface does not exceed 0.5 mm.

RESULTS

Results showed increased asymmetry from T1 to T2. The average distance increased for whole face (from 0.51 mm to 0.59 mm, P = .001), upper face (from 0.41 mm to 0.49 mm, P = .005), mid-face (from 0.48 mm to 0.57, P = .002) and lower face (from 0.74 mm to 0.85 mm, P = .147). Facial symmetry percentage decreased for whole face from 61.23% to 55.38% (P = .011), for upper face from 69.27% to 62.24% (P = .005) and for mid-face from 62.29% to 55.63% (P = .007) and for lower face from 43.37% to 42.19% (P = .66).

CONCLUSION

Facial asymmetry increases from childhood to adulthood in subjects treated for DDH. Orthodontic treatment does not eliminate this asymmetric facial growth.

Accuracy of measurements used to quantify cranial asymmetry in deformational plagiocephaly

OBJECTIVE

Various measurements are used to quantify cranial asymmetry in deformational plagiocephaly (DP), but studies validating cut-off values and comparing the accuracy of such measurements are lacking. In this study, we compared the accuracy of four different measurements in classifying children with and without DP diagnosed by visual assessment, and sought to determine their optimal cut-off values.

STUDY DESIGN

Two experts rated 407 3D craniofacial images of children aged between 3 and 36 months old using the Argenta classification. We then measured the following asymmetry-related variables from the images: Oblique Cranial Length Ratio (OCLR), Diagonal Difference (DD), Posterior Cranial Asymmetry Index (PCAI), and weighted Asymmetry Score (wAS). We created receiver operating characteristic curves to evaluate the accuracy of these variables.

RESULTS

All variables performed well, but OCLR consistently provided the best discrimination in terms of area under the curve values. Subject's age had no clear effect on the cut-off values for OCLR, PCAI, and wAS; however, the cut-off for DD increased monotonically with age. When subjects with discrepant expert ratings were excluded, the optimal cut-off values for DP (Argenta class ≥ 1) across all age-groups were 104.0% for OCLR (83% sensitivity, 97% specificity), 10.5% for PCAI (90% sensitivity, 90% specificity), and 24.5 for wAS (88% sensitivity, 90% specificity).

CONCLUSION

We recommend using OCLR as the primary measurement, although PCAI and wAS may also be useful in monitoring cranial asymmetry. The threshold of relative asymmetry required for a deformation to appear clinically significant is not affected by the child's age, and DD has no additional utility in monitoring DP compared to using only OCLR.

Childhood intelligence and early tooth wear patterns

OBJECTIVE

The aim of this study is to explore the relationships between early dental wear patterns and preschool IQ (Intelligence Quotient, by Stanford-Binet) of the child to illuminate the historic relationship of mental queries and bruxism.

METHODS

The dental study participants were 864 Euro-American preschool and school children whose IQs were tested for school maturity purposes at the age of 4 years, followed by dental data in a cross-sectional manner at the mean age of 7.8 years. Worn dentitions were classified as "symmetric" or "right-" and "left-sided," based on the faceting of the teeth.

RESULTS

In general, the relationships of tooth wear and intelligence were scarce, reflecting social background factors. Statistically significant results between asymmetric wear and gender groups suggest that direction of jaw function has a role in the regulation of processes responsible for individual mental performance in childhood.

DISCUSSION

Increased left-side tooth wear and early advantage in the intelligence test in girls is intriguing due to the fact that they reach maturity earlier than boys in verbal articulation, controlled in most cases by the limited area on the left side of the brain.

The course of positional cranial deformation from 3 to 12 months of age and associated risk factors: a follow-up with 3D imaging

Deformational plagiocephaly is reported in up to 46.6 % of healthy infants, with the highest point prevalence at around 3 months of age. Few prospective studies on the natural course of skull deformation have been conducted, and we know of no studies using 3D imaging starting from the highest point prevalence period. In this prospective, population-based cohort study, we describe the course of cranial asymmetry and shape in an unselected population using 3D stereophotogrammetry and investigate factors associated with late cranial deformation and failure to recover from previous deformation. We evaluated 99 infants at 3, 6, and 12 months of age. We acquired 3D craniofacial images and performed structured clinical examinations and parental interviews at each visit. Eight outcome variables, representing different aspects of cranial shape, were calculated from a total of 288 3D images. Scores of asymmetry-related variables improved throughout the observation period. However, the rate of correction for cranial asymmetry decreased as the infants grew older, also in relation to the rate of head growth, and a significant amount of asymmetry was still present at 12 months. Positional preference at 3 months predicted an unfavorable course of cranial asymmetry after 3 months, increasing the risk for DP persisting. What is known: • The prevalence of deformational plagiocephaly spontaneously decreases after the first months of life. • Limited neck range of motion and infant positional preference increase the risk of deformational plagiocephaly during the first months of life. What is new: • Positional preference at 3 months predicts an unfavorable spontaneous course of deformation also from three to 12 months of age, presenting a potential target for screening and treatment. • The spontaneous rate of correction for cranial asymmetry decreases after 6 months of age, also in relation to the rate of head growth.

Analyzing infant head flatness and asymmetry using kernel density estimation of directional surface data from a craniofacial 3D model

Infant skull deformation is analyzed using the distribution of head normal vector directions computed from a 3D image. Severity of flatness and asymmetry are quantified by functionals of the kernel estimate of the normal vector direction density. Using image data from 99 infants and clinical deformation ratings made by experts, our approach is compared with some recently suggested methods. The results show that the proposed method performs competitively. Copyright © 2016 John Wiley & Sons, Ltd.

Perpendicular serial maxillary distraction osteogenesis in cleft lip and palate patients

BACKGROUND

Cleft lip and palate patients often have a retruded maxilla with a severely narrowed deficient maxillary arch. This report aims to describe the management of severe maxillary retrusion and constriction in cleft lip and palate patients using distraction osteogenesis applied in serial sequence in two directions perpendicular to each other.

MATERIALS AND METHODS

Two adult male cleft lip and palate patients were treated with maxillary distraction osteogenesis in two stages. In the first stage, surgically assisted rapid palatal expansion with a tooth-borne device was performed to significantly expand the maxillary arch in the transverse dimension. After the teeth were orthodontically aligned, the horizontal distraction of the maxilla was made by two internal maxillary distraction devices.

RESULTS

In the first patient, the maxilla was initially widened by 11 mm and then distracted forward by 20 mm. Despite the breakage of the shaft of one of the two distractors at the end of distraction, a satisfactory occlusion was found at the time of distractor device removal. The maxillary position has remained stable through 8 years of follow-up. In the second patient, the palate was widened by 14 mm and the maxilla was distracted forward by 22 mm. The maxillary position has remained stable through 3 years of follow-up.

CONCLUSION

Sequential serial distraction of maxilla in two planes perpendicular to each other is a safe and stable approach for the treatment of cleft lip and palate patients with severe transverse and anteroposterior discrepancies.

Primary tooth size asymmetry in twins and singletons

OBJECTIVES

To explore asymmetry values of antimeric deciduous tooth crown dimensions in three types of twins: monozygotic (MZ), dizygotic same-sex (DZ) and opposite-sex (OS) vs. single-born controls.

SETTING AND SAMPLE POPULATION

Mesiodistal and labio-lingual crown dimensions of second deciduous molars and mesiodistal canine and first molar crown dimensions of 2159 children at 6-12 years of age were evaluated, originating from the US cross-sectional Collaborative Perinatal Study from the 1970s, including altogether MZ (n = 28), DZ same-sex (n = 33) and OS (n = 39) pairs. Single born (n = 1959) were used as controls.

MATERIAL AND METHODS

Dental casts were measured for comparison of variance relationships calculated from antimeric teeth, exhibiting fluctuating (FA), and directional (DA) asymmetry using anova.

RESULTS

Significant differences appeared in MZ and OS girls in DA of deciduous canines, which gain size in the first and second trimester, and deciduous second molars, which finally stop crown growth during the early post-natal period. Significantly, increased FA values appeared for lower deciduous canines and second molars, indicating greatest environmental stress in OS girls, MZ girls and DZ boys. Twin girls had more fluctuating and directional crown asymmetry than twin boys, but in some dimensions, the twins were more symmetric than controls.

CONCLUSIONS

Transmembrane hormonal influence between opposite-sex twins, and late gestational stress factors, caused by placental malfunction and/or monochorionicity, may be involved in asymmetric growth of antimers, during critical periods of crown size gain.

Can the results of the OSCE predict the results of clinical assessment in dental education?

INTRODUCTION

The aims of this study were to evaluate the correlation between the results of the objective structured clinical examination (OSCE) and clinical assessment and to test the reliability of OSCE test stations.

MATERIAL AND METHODS

All 4th year undergraduate dental students (n = 47, 100%) attended the OSCE in April 2010. The students were divided into two groups (morning group, group 1; afternoon group, group 2). Groups 1 and 2 were also divided into two subgroups that attended the stations in two concurrent sessions (A and B). The OSCE included 12 10-min test stations. Clinical assessment was based on long-term observation during the semesters. The disciplines assessed were cross-infection control, endodontics, paediatric dentistry, periodontology, prosthodontics and restorative dentistry.

RESULTS

Statistical analysis using Cronbach's alpha indicated good reliability of the OSCE. The correlation between the results of the OSCE and clinical assessment in the 4th year was statistically significant in cross-infection control (ρ = 0.340, P = 0.022), endodontics (ρ = 0.298, P = 0.047), prosthodontics (ρ = 0.296, P = 0.048) and restorative dentistry (ρ = 0.376, P = 0.011). Clinical assessment in the 5th year correlated with the OSCE results statistically significant in restorative dentistry (ρ = 0.522, P = 0.001).

CONCLUSION

Both the OSCE and constant longitudinal assessment are needed in clinical assessment, as they both play an important role in the overall assessment.

The association of cleft severity and cleft palate repair technique on hearing outcomes in children in northern Finland

BACKGROUND

The consequences of cleft lip and palate include scaring, dental malformations, tooth misalignment, speech problems, and hearing loss. Otitis media with effusion causing hearing loss is a problem for many cleft palate patients.

METHODS

This study examines the association among cleft severity, palate repair technique, and hearing outcomes in children from northern Finland with clefts, aged 3-9 years. The study included 90 cleft patients who were treated at the Oulu University Hospital Cleft Lip and Palate Center between 1998 and 2011. The severity of the cleft, the surgical technique used to repair the palate, audiogram configuration data, and the need for ventilation tube placement were determined retrospectively from patient records.

RESULTS

Only 3.3% of cleft patients had an abnormal pure tone average hearing threshold representing abnormal hearing. Neither the surgical technique used to repair the cleft palate nor the severity of the cleft was a significant factor related to hearing loss or to the number of ventilation tubes required. Hearing improved significantly with increasing age over a span of 6 years.

CONCLUSIONS

Continuous follow-up with proactive placement of ventilation tubes before or at the time of palatoplasty results in hearing outcomes in cleft children that are similar to those reported in non-cleft children.

Dental arch relationships assessed by GOSLON Yardstick in children with clefts in Northern Finland

AIM

Our purpose was to evaluate the dental arch relationships using the GOSLON Yardstick in children with cleft lip and or cleft palate in Northern Finland.

MATERIALS AND METHODS

The subjects consisted of 62 Finnish patients (36 girls and 26 boys) with clefts born between 1995-2005 in the Northern Ostrobothnia Hospital District of Finland. There were 36 patients with cleft palate, 9 with unilateral cleft lip and palate, 6 with cleft in soft palate, 5 with bilateral cleft lip and palate, 2 with cleft lip and 4 with submucous clefts. The study casts were obtained at the mean age of 6.3 years (5.8-7.8 years) and the cases were selected randomly. The dental arch relationships were assessed by the GOSLON Yardstick method by one calibrated researcher.

RESULTS

After the assessment, 77.1% of cases were allocated to categories 1 and 2 (excellent and good), 10.4% category 3 (fair), and 12.5% categories 4 and 5 (poor and very poor). Patients with cleft palate had good prognosis in 84.6% of the cases. Of the patients with soft palate clefts and unilateral cleft lip and palate, 66.7% were allocated to categories 1 and 2. Bilateral cleft lip and palate patients had the poorest prognosis. Patients with submucous cleft and cleft lip had all good prognosis.

CONCLUSION

The GOSLON Yardstick is a useful method for assessing dental arch relationships and treatment prognosis not only in cleft lip and palate patients, but also in cleft palate patients.

A descriptive epidemiology study of cleft lip and palate in Northern Finland

OBJECTIVE

The aim of this study was to determine the incidence of cleft lip and/or cleft palate in a population uniquely from Northern Finland.

MATERIALS AND METHODS

The records of a total of 214 cleft patients treated between 1998-2011 at the Oulu Cleft Lip and Palate Center at the University of Oulu were assessed on a retrospective basis. Data regarding cleft type, sex and side of cleft was collected and analyzed. Family history of clefting was investigated.

RESULTS

Cleft palate (68.7%) was most frequently found, followed by cleft lip and palate (18.7%) and cleft lip with or without alveolus (12.6%). Cleft palate occurred more frequently in females (63.3%) and cleft lip and palate was more frequently found in males (62.5%). The left side was more frequently affected in both male and female patients. Left-sided clefts were observed in 82% of patients compared to right-sided clefts in 18%. A family history of clefting was detected in 20.1% of patients.

CONCLUSION

The incidence of clefts in Northern Finland is higher than the corresponding incidence in other European countries. Cleft palate was the most frequent cleft type and it was more frequent in females. In males, cleft lip and palate was more frequent. The left side was more frequently affected in both genders. One fifth of the patients had a family history of clefts.

Masculinization of the eruption pattern of permanent mandibular canines in opposite sex twin girls

The aim of this study is to explore the effect of prenatal androgenization on the clinical eruption of permanent teeth expressing dimorphism and bimaturism. The eruption curves of permanent teeth (except third molars), including those that make up the canine complex (permanent canines, lower first premolars), are compared among opposite sex twins (OS twins) relative to single-born boys and girls. The comparisons are made with regard to three phases of eruption (pierced mucosa, half- erupted, and completely erupted) from a cross-sectional sample of dental casts, using Kaplan-Meier survival and Cox regression analyzes. The casts were collected from 2159 school children from the US Collaborative Perinatal Project, including 39 pairs of OS-twins, of which 12 pairs (30.8%) were Euro-Americans and 27 pairs (69.2%) were of African-American ancestry. The eruption patterns of the incisors, upper first molars, and lower canines were found to be significantly masculinized (delayed) among OS twin girls. The differences in most other teeth were either not significant, or the number of observations of active eruption phases were too few, such as in the upper first molars and incisors, to yield strong evidence and meaningful results. The masculinization of the tooth eruption pattern in OS twin girls is intriguing because of the lower canine responses during puberty, as well as canine primordial formation during early fetal androgenization of their co-twin during the 8th to 14th gestational weeks. The present results offer a challenge for future research exploring tooth eruption mechanisms, and may also highlight some cases of delayed or ectopic canines, which are biased toward females.

Maxillary arch dimensions in cleft infants in Northern Finland

OBJECTIVE

The aim of this study was to examine the maxillary arch dimensions in cleft lip and/or palate infants in Northern Finland before surgery.

MATERIALS AND METHODS

The subjects consisted of 70 Finnish cleft patients born between 1997-2004 in Northern Ostrobothnia Hospital District in Finland. The study casts were obtained before surgery at the mean age of 5.6 months (SD = 2.2). There were 42 children with cleft palate (CP) (26 girls/16 boys), 13 with unilateral cleft lip and palate (UCLP) (eight girls/five boys), eight children with cleft lip (CL)(two girls/six boys) and seven with bilateral cleft lip and palate (BCLP) (two girls/five boys). Conventionally-used landmarks were marked on study casts and cleft width, arch circumference, anterior and posterior arch width and arch length were measured with a digital sliding calliper. The statistical method was ANOVA.

RESULTS

The prevalence of CP in this study, 60% of all clefts, is higher than the average standards. There were statistically significant differences in cleft width, posterior and anterior arch width, arch length and arch circumference, when different cleft groups were compared. When differences between girls and boys were compared, boys had larger cleft size and arch dimensions generally, but the results were not statistically significant.

CONCLUSIONS

The results show the large variation in the severity of cleft lip and/or palate deformity at birth and in maxillary arch dimensions between different cleft types. It also demonstrates the effect of phenotypic variability within the groups of cleft lip and/or palate.

Experiences in adding multiple-choice questions to an objective structural clinical examination (OSCE) in undergraduate dental education

In the University of Oulu, the competencies of fourth-year dental students have traditionally been assessed with a written examination before they go to work for the first time as dentists outside the Institute of Dentistry. In 2009, the objective structural clinical examination (OSCE) modified with multiple-choice questions was introduced as a tool for assessing clinical competencies. The aim of the study was to evaluate the validity of the modified OSCE (m-OSCE) by measuring the attitude of examiners (teachers) and dental students towards the m-OSCE and to evaluate whether the OSCE is preferred to the written examination in the assessment of knowledge and clinical skills. Additionally, the aim was to evaluate the reliability of the multiple-choice examination. Altogether 30 students (86%) and 11/12 examiners (92%) responded to the questionnaire. Most of the students considered the multiple-choice questions easy, but complained about the complex formulation of the questions. The test stations were easy for 87% of the students, but the time allocated was too short. Most of the students (73%) and examiners (91%) preferred the m-OSCE to the written examination. All students and examiners found the immediate assessment of the tasks good. Based on the evaluations of m-OSCE, it could be concluded that both students and examiners preferred the m-OSCE to the pure written examination in assessment, which indicate that m-OSCE had good face validity. Combining multiple methods in assessment of knowledge and clinical skills whilst simultaneously taking into account the feasibility and available resources provides more valid results.

Facial morphology of Finnish children with and without developmental hip dysplasia using 3D facial templates

BACKGROUND

Developmental dysplasia of the hip (DDH) is a condition that affects the femoral head and the acetabulum and leads to hip subluxation and dislocation. Infants with DDH are usually treated using splints that immobilize their hip joint and are forced on their back for long periods of time. The link between positioning and facial asymmetries is poorly understood.

OBJECTIVE

To compare the facial morphologies of children with DDH to a group of healthy controls.

SUBJECTS AND METHODS

Fifty-six Finnish patients born with DDH were matched on the basis of gender and age to a control group. Three-dimensional surface images were captured using the 3dMDface system. Using RF6 PP2 software, anthropometric landmarks were plotted and used to calculate asymmetry based on 3D co-ordinates in a reference framework.

RESULTS

There was statistically significant difference between all paired facial shells. Relative to the control group, DDH boys and girls presented a chin-point deviation to the right, a more prominent left orbital ridge, a more protrusive nose and upper lip. The gender-specific subgroups show a similarity of 66.54 and 65.22% in girls and boys, respectively.

CONCLUSIONS

Patients with DDH present a facial asymmetry when compared to healthy controls. Gender characteristics are marked whether subjects are affected with DDH or not. Three-dimensional surface imaging is a powerful diagnostic and research tool.

Occlusal asymmetries in children with congenital hip dislocation

Developmental dysplasia of the hip (DDH) has been associated with other congenital postural deformities and associated with asymmetric features in the body. The aim of this study was to examine the associations between developmental DDH and malocclusions in preschool and school children. The subjects were 60 children (40 girls and 20 boys) born during 1997-2001 in Northern Ostrobothnia Hospital District and having developmental DDH and treated by Von Rosen method. The control group consisted of 71 Finnish children (46 girls and 25 boys) matched by age and gender. Children participated the cross-sectional study at the age of 5-10 years; the mean age of the DDH children was 8.0 (SD 1.4) and controls 7.9 (SD 1.4) years. Dental examinations, intra-oral photographs, and clinical examination including growth measurements were carried out. The DDH children had significantly more lateral crossbites than controls (30/9.9 per cent; P < 0.003). Overall, 77.8 per cent of cases were unilateral crossbites and found more on the right side (50 per cent) compared to the left side (22.2 per cent). Girls had more crossbite compared to boys (77.8/22.2 per cent; odds ratio 2.53). Children with congenital hip dislocation are more predisposed to the asymmetric growth of occlusion and the development of crossbite. The genetic and environmental factors including intrauterine conditions in addition to the splint therapy may be possible influencing factors. This study will give additional information of the development of occlusal asymmetries and the multifactorial nature of the aetiology of lateral malocclusions.

Primary tooth wear in functional lateralities

PURPOSE

The purpose of this study was to explore the sidedness of primary tooth horizontal wear facets between the left and right sides of the dentition among 2 types of functionally lateralized (hand, foot, eye) children--those who were true right-sided (TRS), and partially or totally nonright-sided (NRS) at 4 years of age.

METHODS

Study subjects were 855 children with signs of wear in deciduous teeth on the dental casts (N=1,720) of the GOS (Genetic Odontometric Study of the Collaborative Perinatal) project, carried out in the 1960s in the United States by the National Institute of Neurological Disorders and Stroke (NINDS) in a cross-sectional manner at a mean age of 8(1/2) years (40% Caucasian and 60% African-American children). The statistical method used was chi-square analysis.

RESULTS

Tooth wear was identified from dental casts in approximately 50% of cases. Wear was symmetric (equal on the right and left) in 49% of these dentitions, while asymmetric wear was found in 50%. Left-sided extra wear was slightly more common (26%) than right-sided extra wear (24%), but gender and race differences appeared. Statistically significant unilateral wear was found among TRS Caucasian boys on the dentition's right side. In NRS Caucasian boys, however, the left-sided extra wear was more common than for the right-sided extra wear (P=.04). In Caucasian girls, the same relationship appeared, but the difference was not significant (P=.11). In African American TRS children, the left-sided extra wear was more common, and symmetric proportion was increased in boys. The differences between laterality and gender groups, however, were not statistically significant.

CONCLUSIONS

Sidedness in the form and function of a primary dental apparatus has variation among gender and race groups that is involved with the determination of general structural and functional lateralities. Early asymmetric oral functioning (unilateral bolus placement, sucking, chewing, bruxism, etc) should be considered in registration of the various phases of occlusal development, also having craniofacial aspects due to asymmetric growth promoting function.

Open bite in prematurely born children

PURPOSE

The aims of this study were to: examine the expression of open bite in prematurely born children and discuss the etiological factors that may lead to bite it.

METHODS

The subjects were 328 prematurely born (<37 gestational weeks) Caucasoid and African American children and 1,804 full-term control children, who participated in the cross-sectional study of the Collaborative Perinatal Project in the 1960s and 1970s. Dental documents, including casts and photographs, were taken once at the age of 6-12 years in the mixed dentition. The occlusion was recorded by examining and measuring the hard stone casts. Vertical open bite was recorded only for full erupted teeth. The statistical method used was chi-square analysis.

RESULTS

Significant differences in the incidence of anterior open bite (from left to right canine) was found between the preterm and control groups and between gender and ethnic groups. The prevalence of anterior open bite was nearly 9% in the preterm group and almost 7% in the control group. African Americans (9%) had a significantly greater incidence of open bite than Caucasians (3%; P<.0001). Generally, girls had a greater incidence of open bite than boys (8% vs 6%; P<.11). When the study groups were divided by prematurity, gender, and ethnic group, the prevalence of open bite was increased--especially in preterm African American boys compared to controls (11% vs 8%).

CONCLUSIONS

The results show differences in the development of anterior open bite between ethnic and gender groups. Premature birth may also influence dental occlusal development. Of importance are the patient's: general health condition; respiratory infections; inadequate nasal- and mouth-breathing; oral habits; and other medical problems. Preterm children may be relatively more predisposed to etiological factors for the development of anterior open bite.

Deciduous tooth crown size in prematurely born children

AIM

The purpose of our study was to examine deciduous tooth crown size in preterm children.

SUBJECTS AND METHODS

The subjects consisted of 328 prematurely born (< 37 gestational weeks) white and black children and 1804 controls, who participated in the cross-sectional study of the Collaborative Perinatal Project (USA) in the 1960s and 1970s. Documents of the present research consisted of dental casts of the 6-12 years old children. Tooth crown measurements on canines and molars were performed on the dental casts with an electronic measuring device according to precise definitions generally quoted in the anthropological and genetic literature. For the results, the preterm and control groups were divided by sex and race.

RESULTS

There were both increased and decreased mesiodistal and labiolingual tooth crown dimensions in prematurely born children, but no significant differences between the study groups was found.

CONCLUSIONS

The findings of the present research suggest that short gestation is not associated with reduced deciduous tooth crown size as suggested by earlier studies and are parallel with our previous results of permanent tooth crown dimensions in prematurely born children. Boys showed clearly larger tooth crown sizes than girls within all preterm and control groups. This indicates that sexual dimorphism is apparent in its final form beginning some months after birth.