Evaluation of Growth and Development of Late Mixed Dentition Upper Dental Arch with Normal Occlusion Using 3-Dimensional Digital Models.

Objective: The purpose of this study was to observe the three-dimensional growth and development of the maxillary arch in 10-year-olds with normal occlusion during the late mixed dentition stage. Methods: Forty-four 10-year-old students (22 males and 22 females) who had normal occlusion during late mixed dentition were selected from an elementary school in Beijing, China. Once per year for three consecutive years, a dental cast was obtained from each subject, and the cast was scanned with a 3D digital scanner (R700 3D). The three-dimensional measurements of the maxillary dental arch and the inclination of the bilateral maxillary first molars were obtained from the digital model. Results: The upper anterior arch length (UAAL), upper total arch length (UTAL), upper inter primary or permanent canine width (UICW), upper intermolar width (UIMW), and upper dental arch length (UDAL) increased by 0.959 mm, 0.583 mm, 0.955 mm, 1.462 mm, and 2.46 mm, respectively, over the two years (P < 0.001). UR6BL and UL6BL decreased by 4.416° and 7.133°, respectively, over the two years (P < 0.001). The values of the UICW and UIMW were 1.67 mm and 1.86 mm, respectively, larger in males than in females at 12 years old (P < 0.01). The change in the UTAL was 0.431 mm greater in males than in females over the 2 years (P < 0.05). Conclusion: The UAAL, UTAL, UICW, UIMW, and UDAL in 10- to 12-year-olds with normal occlusion increased with age. The buccolingual inclination of the bilateral maxillary first molars inclined to the palatal side with age. The UICW and UIMW were larger in males than in females at 12 years old. The male UTAL increased more than the female UTAL over the 2 years.

Adolescent dental arch development among Southern Chinese in Hong Kong: a geometric morphometric approach.

This study aimed to investigate changes in types of dental arch form during adolescence and explore adolescent changes in size and form of dental arch. Hong Kong Chinese were recruited and digital dental arch models were obtained at ages 12, 15, and 18 years. Geometric morphometrics was used to investigate adolescent changes of dental arch form. There were 225 participants from whom digital models at all three age periods were available. Three types of dental arch form were identified through clustering. Significant changes (p < 0.001) in types of dental arch form were noted during age 12-18 years. During age 12-18 years, significant changes in centroid size and form of dental arch were observed (p < 0.001). No significant changes were observed during 15-18 years. Adolescent changes of dental arch form occur primarily during age 12-15 years, whereas dental arch form was relatively stable during age 15-18 years.

Association between snoring and deciduous dental development and soft tissue profile in 3-year-old children.

INTRODUCTION: The aim was to study the association between snoring and development of occlusion, maxillary dental arch, and soft tissue profile in children with newly completed deciduous dentition. METHODS: Thirty-two (18 female, 14 male) parent-reported snorers (snoring ≥3 nights/week) and 19 (14 female, 6 male) nonsnorers were recruited. Breathing preference (nose or mouth) was assessed at the mean age of 27 months by otorhinolaryngologist. At the mean age of 33 months, an orthodontic examination was performed, including sagittal relationship of second deciduous molars, overjet, overbite, and occurrence of crowding and lateral crossbite. Bite index was obtained to measure maxillary dental arch dimensions (intercanine and intermolar width, arch length). A profile photograph was obtained to measure facial convexity. RESULTS: No significant differences were found between nonsnorers and snorers in any of the studied occlusal characteristics or in measurements of maxillary dental arch dimensions. Snorers were found to have a more convex profile than nonsnorers. Occurrence of mouth breathing was more common among snorers. CONCLUSIONS: Parent-reported snoring (≥3 nights/week) does not seem to be associated with an adverse effect on the early development of deciduous dentition, but snoring children seem to have more convex profile than nonsnorers. Snoring is a mild sign of sleep-disordered breathing, and in the present study its short time lapse may not have had adequate functional impact on occlusion.

Relation of dietary preference to masticatory movement and masticatory exercises in Japanese children.

OBJECTIVE: Modern Japanese children have decreased masticatory function, which can be explained by the dietary change to soft foods. In earlier studies involving children with mixed dentition, masticatory exercises were shown to improve masticatory function and modify dental arch growth. Grinding type of mastication with a wide path reportedly increases lateral growth of the dental arch. This study aimed to assess the relationship between masticatory movements and dietary preference, and how masticatory exercises affected masticatory movement during Hellman's dental stages IIA to IIC (period of first molar eruption). DESIGN: In 64 Japanese pre-school children, we measured masticatory movements with foods of five different levels of hardness and investigated the dietary preference for hard foods through a questionnaire. Participants were also required to perform masticatory exercises. Masticatory movements and dietary preference for hard foods were assessed at the start (T1), conclusion (T2), and after six months of exercises (T3). Participants were allocated to Wide and Narrow groups at T1 based on their masticatory path width. RESULTS: Baguettes and bananas resulted in the widest and narrowest masticatory paths, respectively, at T1. Results of questionnaire indicated that those eating hard foods had a broad grinding type of masticatory path. Masticatory exercises significantly widened the masticatory path in the Narrow group demonstrating that masticatory exercises help children learn to chew with grinding strokes. Moreover, the masticatory path remained stable on assessment at T3 (six-month follow-up). CONCLUSIONS: Masticatory exercises are effective in children who are unable to grind hard foods, affecting their dietary preferences.

Changes of mandibular dental arch shape during adolescence and its influence on late mandibular incisor crowding.

The aim was to analyze the changes in mandibular dental arch shape during adolescence and assess its relation to late mandibular incisor crowding. Longitudinal study included 68 orthodontically untreated subjects (49% female) and analyzed their data for the ages of 12, 15, 18 and 21 years. Measurements included anterior arch depth, intercanine, interpremolar/anterior and intermolar/posterior width, Little's Irregularity and Bolton's index and the ratio between anterior arch depth and width. Males had significantly greater posterior widths than females at any age (p < 0.05). The anterior arch depth continuously decreased (p < 0.05), while width increased after the age of 18 years. Mandibular incisor crowding increased during all investigated periods (p < 0.05). The increase of intercanine width at 12-21 years of age reduced the risk for mandibular incisor crowding in the same period by 74% (OR: 0.265: 95% CI 0.076-0.931; p = 0.045). The shape of mandibular dental arch continues to change during adolescence becoming more squared while mandibular incisor crowding increases. The increase in mandibular intercanine width reduces the risk of crowding.

Analysis of Dental Arch in Children With Oral Cleft Before and After the Primary Surgeries.

This study aimed to evaluate longitudinally the alteration of the dental arch dimensions of children with different oral cleft types, before and after the primary surgeries. Three-dimensional images of the maxillary dental casts of children with unilateral complete cleft lip (G1), unilateral complete cleft lip and palate (G2), and cleft palate (G3). The children were evaluated at pre-cheiloplasty (T1), pre-palatoplasty (T2), and 1 year after palatoplasty (T3). The measurements obtained: intercanine (C-C') and intertuberosity (T-T') distances, anterior (I-CC') and total (I-TT') arch lengths. To analyze the intraexaminer error, paired t-test was applied and Dahlbergh formula. The intragroups comparisons were applied: paired t-test, ANOVA followed by Tukey, Wilcoxon test, and Kruskal-Wallis test followed by Dunn test. The intergroup comparisons were performed by independent t-test and Mann-Whitney test. In G1, the C-C', T-T', and the I-TT' distances revealed a significant increase of the maxilla. In G2, the C-C' distance statistically decreased from T1 to T3, T-T' distance showed statistical increase from T1 to T3. The I-TT' length increased with statistically significant differences between T1 and T3, T2 and T3. In G3, the C-C', T-T', and I-TT' distance increased was statistically significant. The longitudinal evaluation of the changes occurred in the dental arches with different oral cleft types showed that cheiloplasty and palatoplasty caused the most alterations in the development of the maxillary dimensions of children with complete cleft lip and palate.

Factors associated with masticatory performance and swallowing threshold according to dental formula development.

OBJECTIVE: The aims of the present study were to the determine changes in, and factors related to, masticatory performance and swallowing threshold according to dental formula development. METHODS: A total of 120 subjects, ranging in age from 4 to 19, and 21 to 29 years, were included in the present study. Grip strength and maximum occlusal force were measured in all subjects. Masticatory performance and swallowing threshold (including the number of chewing cycles and chewing time), were determined according to the concentration of dissolved glucose obtained from gummy jellies. The 12-item General Health Questionnaire (GHQ-12) was used to assess mental health status in participants 21 to 29 years of age. RESULTS: In the primary dentition, masticatory performance and glucose concentration before swallowing were the lowest in all dentition groups. Masticatory performance was the highest in subjects 21-29 years of age. In children with mixed and permanent dentition, glucose concentration levels before swallowing were similar to those in individuals aged 21-29 years. Multiple regression analysis revealed that maximum occlusal force was significantly and positively correlated with glucose concentration before swallowing in children, and the GHQ-12 score was significantly and negatively correlated with glucose concentration before swallowing in young adults. CONCLUSIONS: Changes in swallowing threshold did not coincide with masticatory performance according to dental formula stage. Maximum occlusal force was the variable most strongly associated with swallowing threshold in children, while in young adults, better mental health status was closely associated with a higher swallowing threshold.

Three dimensional maxillary growth modeling in newborns.

OBJECTIVES: The aim of this study was to develop an accurate and intuitive semi-automatic segmentation technique to calculate an average maxillary arch and palatal growth profile for healthy newborns in their first year of life. MATERIALS AND METHODS: Seventy babies born between 1985 and 1988 were included in this study. Each child had five impressions made in the first year after birth that were digitalized. A semi-automatic segmentation tool was developed and used to assess the maxillary dimensions. Finally, random effect models were built to describe the growth and build a simulation population of 10,000 newborns. The segmentation was tested for inter- and intra-observer variability. RESULTS: The Pearson correlation coefficient for each of the variables was between 0.94 and 1.00, indicating high inter-observer agreement. The paired sample t test showed that, except for the tuberosity distance, there were small, but significant differences in the landmark placements between observers. Intra-observer repeatability was high, with Pearson correlation coefficients ranging from 0.87 to 1.00 for all measurements, and the mean differences were not significant. A third or second degree growth curve could be successfully made for each parameter. CONCLUSIONS: These findings indicated this method could be used for objective clinical evaluation of maxillary growth. CLINICAL RELEVANCE: The resulting growth models can be used for growth studies in healthy newborns and for growth and treatment outcome studies in children with cleft lip and palate or other craniofacial anomalies.

Changes in the mandibular dental arch during the late mixed dentition stage: Experimental study.

OBJECTIVE: To determine the dimensional changes in the mandibular arch of untreated subjects during the late mixed dentition stage. METHODS: The cross-sectional study was conducted over three years starting March 2013 at the College of Dentistry, King Saud University, Riyadh, Saudi Arabia, and comprised consecutive models taken annually of subjects seeking dental treatment. They were aged 9 years at baseline and dimensional changes were calculated at 9, 10 and 11 years of age. Measurements taken each year were overjet, overbite; inter-canine width, canine length, inter-first deciduous molar width, inter-first premolar width, inter-first permanent molar width, arch length, molar depth, incisor irregularity, and available anterior space. SPSS 16 was used for data analysis. RESULTS: Of the 15 subjects, 10(66.6%) were girls and 5(33.3%) were boys. Of all the variables, the mean values of overbite (p=0.006) and inter-canine width (p=0.001) increased significantly over the period, while the mean irregularity index values decreased significantly (p<0.0001).. CONCLUSIONS: An increase in overbite and inter-canine width, and a reduction in the irregularity index of teeth was detected during the mixed dentition phase.

The Elimination of Dental Crowding and Development of a Proper Dental Arch by Maxillary Anterior Segmental Distraction Osteogenesis for a Patient With UCLP.

OBJECTIVE: This report describes the case of a male patient with a complete unilateral cleft lip and palate who presented with midface deficiency and an anteroposteriorly constricted maxilla. DESIGN: Case report Interventions: Correction involved anterior distraction of the segmented maxilla. RESULTS: The present case demonstrates that elongation of the maxilla with anterior distraction is an effective way to develop a proper dental arch, correct anterior and posterior crowding, and improve a midface deficiency.

Prediction of dental arch width increase in the early mixed dentition using craniofacial parameters.

BACKGROUND: The dimensions of the dental arch have considerable impact on treatment planning. Since the dental arch development has a relationship with the craniofacial growth, we designed a cohort study to find a regression model for predicting the mandibular arch width increase using craniofacial parameters. METHODS: A total of 148 children, all in early mixed dentition, were selected randomly from primary schools by cluster sampling. Craniofacial anthropometric parameters were measured by a caliper bow and intercanine and intermolar widths were assessed on each subject's dental casts by a digital caliper at baseline and after 12 months. Data were analyzed with SPSS v. 15. Student's t-test and linear regression test were applied separately for girls and boys. RESULTS: Out of 153 children, 148 returned for one-year follow-up meeting the inclusion criteria. The results of regression analysis showed a significant inverse correlation between intercanine width and facial index. The bigonial dimension showed a high correlation with both the intermolar width and the intercanine width increase. CONCLUSIONS: We found that the arch width increase in the early mixed dentition could be predicted precisely based on certain craniofacial parameters.

Do gender and age influence hard palate dimensions? A systematic review. / O gênero e a idade influenciam as dimensões do palato duro? Revisão sistemática da literatura.

PURPOSE: Analyze the influence of gender and age on hard palate dimensions and verify the reference parameters available in the literature. RESEARCH STRATEGIES: Two reviewers independently performed a search at the Cochrane Library, PubMed-Medline and Web of Knowledge databases using descriptors according to the syntax rules of each database. SELECTION CRITERIA: Observational or experimental human studies evaluating the dimensions of the hard palate or maxillary dental arch, with at least one transverse, vertical or sagittal plane measurement, in normal occlusions or class I malocclusions, and comparisons of the dimensions between genders and/or ages. DATA ANALYSIS: Descriptive analysis with the following subdivisions: design, sample, evaluation instruments, measurements in millimeters, and statistical analysis. Quality of the included studies was verified by the Newcastle - Ottawa Quality scale. RESULTS: Eighteen studies were selected and 11 presented results for hard palate or maxillary dental arch dimensions according to gender, six in age and gender and one in age only. CONCLUSION: The dimensions were larger in males and progressive increase in the measurements was observed from birth to the permanent dentition period.

OBJETIVO: Analisar a influência do gênero e da idade nas dimensões do palato duro, bem como verificar os parâmetros de referência disponíveis na literatura. ESTRATÉGIA DE PESQUISA: Dois examinadores realizaram a pesquisa de forma independente nas bases de dados Cochrane Library, PubMed-Medline e Web of Knowledge utilizando os descritores de acordo com as regras de sintaxe de cada banco de dados. CRITÉRIOS DE SELEÇÃO: Estudos em humanos observacionais ou experimentais, que avaliaram as dimensões do palato duro ou do arco dentário maxilar com pelo menos uma mensuração no plano transversal, vertical ou sagital em oclusões normais ou más oclusões classe I e que realizaram comparações das dimensões entre os gêneros e/ou idades. ANÁLISE DE DADOS: Análise descritiva, seguindo subdivisões: delineamento, amostra, instrumentos de avaliação, medidas em milímetros e análise estatística. A qualidade dos estudos incluídos foi verificada através da escala "Newcastle - Ottawa Quality". RESULTADOS: Foram selecionados 18 estudos. Destes, 11 apresentaram resultados das dimensões do palato duro ou do arco dentário maxilar conforme o gênero, seis em idade e gênero e um somente em idade. CONCLUSÃO: As medidas foram maiores no gênero masculino e houve um aumento progressivo nas dimensões do nascimento até o período de dentição permanente.

Early versus late alveolar bone grafting in unilateral cleft lip and palate: Dental arch relationships in pre-adolescent patients.

OBJECTIVE: To evaluate the dental arch relationship in preadolescent children with complete unilateral cleft lip and palate after early secondary alveolar bone grafting (E-ABG) by comparing to late bone grafting (L-ABG). MATERIAL AND METHODS: Two raters blindly assessed the dental arch relationship with the modified Huddart-Bodenham (HB) Index for 2 groups: E-ABG group (36 children, mean age 9.6 years) and L-ABG group (56 children, mean age 11.1 years). The groups differed with respect to age at which alveolar bone grafting was performed: between 1.4 and 4.1 years (mean 2.2 years, E-ABG group) and after 8 years (L-ABG group). T-test was run to compare scores between 2 groups. Regression analysis was carried out to evaluate gender, age at cleft repair, age at ABG, and age at assessment with the HB index. RESULTS: The overall HB scores were -6.77 and -4.25 in the E-ABG and L-ABG groups, respectively (p = 0.025). Regression analysis showed that only the age at cleft repair influenced the HB scores. CONCLUSION: ABG carried out between 2 and 4 years of age does not seem to negatively affect the dental arch relationship at the age of 10 years in comparison to L-ABG.

Unilateral Cleft Lip and Palate Surgical Protocols and Facial Growth Outcomes.

BACKGROUND: Adequate dentofacial growth is an objective of unilateral cleft lip and palate treatment. No study exists, comparing the dental arch of 5-year-old relationship after 2 treatment protocols: one with single-stage palatoplasty and another with delayed hard palate closure (DHPC). The authors hypothesized that the DHPC protocol provides better dentofacial growth. METHODS: A single-center, single-surgeon Randomized Clinical Trial was performed to evaluate the maxillomandibular relationships in 2 groups. The intervention group (GI) underwent palatoplasty with DHPC between ages 3 and 4 years; the control group (CG) underwent complete palatoplasty between 9 and 15 months. The authors evaluated oronasal fistulae rates.The dental arch relationship was evaluated via blinded panels using the Five Year Old Index.Kappa statistics were calculated to assess reliability. Trials were statistically tested with the t test and chi-squared test. RESULTS: Sixty-four patients constituted the study sample. The incidence of oronasal fistulae was 9.4% (GI) and 6.7% (CG). Sixty-two models with an average age of 55 months were available for analysis. Good intra- and inter-rater reliabilities (0.73-0.93 and 0.60-0.94, respectively) were obtained. Average index scores ranging from 2.04 (GI) to 2.76 (CG) were significantly different (P = 0.007). Significant between-group differences (P = 0.006) were found in scores, 1 and 2 in the GI (74%) and CG (52%). When the distributions were compared by the median, a difference was found (P = 0.024) in score, 1 between the GI (31.2%) and CG (3.3%). CONCLUSIONS: Although the DHPC protocol yielded better outcomes relating to dentofacial growth, other protocols should be investigated and findings verified by other researchers.

Longitudinal morphometric analysis of dental arch of children with cleft lip and palate: 3D stereophotogrammetry study.

OBJECTIVE: This study aimed to perform a longitudinal morphometric analysis of the alterations of the maxillary dental arches in children with cleft lip and palate before and after primary lip and/or palate surgeries using a 3-dimensional stereophotogrammetry system. STUDY DESIGN: The sample consisted of dental casts of 60 children with complete unilateral cleft lip (UCL) and complete unilateral cleft lip and palate (UCLP). Dental arches were evaluated before cheiloplasty (T1), after cheiloplasty (T2), and 1 year after palatoplasty (T3). Independent t test and Mann-Whitney U test were used for intergroup comparisons, and paired t test, Wilcoxon's test, and repeated-measures analysis of variance (ANOVA), followed by Tukey's test, were used for intragroup comparisons. RESULTS: At T1, the intercanine and intertuberosity distances in the UCLP group were statistically greater than those in the UCL group. At T2, the maxillary dimensions significantly increased, except for the intertuberosity distance in UCL. Between T1 and T3, the intercanine distance and the anterior length decreased significantly, whereas the intertuberosity distance and the total length of the palate increased significantly. CONCLUSIONS: Our results indicated that the primary lip surgery altered the development of dental arches, evidently in children with UCLP. The primary palate surgery interfered in the growth of the anterior palatal region in the UCLP group. Children with UCLP had more restricted development of the maxillary dental arch compared with children with UCL.

Midfacial growth and dental arch relationships in bilateral cleft palate following secondary alveolar bone grafting and orthodontic intervention: Factors predicting a Le Fort I osteotomy at age 18.

OBJECTIVE: To evaluate midfacial growth and dental arch relationships in patients treated for bilateral cleft lip and palate (BCLP). MATERIALS AND METHODS: Data were collected from all patients with BCLP treated at our hospital between 2004 and 2014, with or without premaxillary osteotomy (PO). Dental casts for pre-secondary alveolar bone grafting with PO (SABG + PO) and end-point dental casts were analyzed using the BAURU yardstick scoring system. Pre-SABG + PO, post-SABG + PO, and end-point SABG + PO lateral cephalograms were analyzed. The correlation between both scoring systems was calculated. RESULTS: There were no significant differences between the BAURU scores for centers in a previous study and those collected here. A negative correlation was found between the pre-SABG + PO ANB (Angle between A-point, Nasion and B-point) angle and pre-SABG + PO BAURU scores (R = -0.58; p = 0.000), the long-term post-SABG + PO ANB and mean end-point BAURU (R = -0.50; p = 0.000), and the pre-SABG + PO ANB and mean end-point BAURU (R = -0.51; p = 0.000). CONCLUSION: We found no significant difference between pre-SABG + PO and end-point BAURU scores. There was a decrease in the SNA (Angle between Sella, Nasion and A-point) and ANB angle over time, indicating delayed growth of the maxilla. We found a negative correlation between the pre-SABG ANB and end-point BAURU scores. Pre-SABG ANB can be used to predict the need for Le Fort I osteotomy at age 18.

Maturational changes of the normal occlusion: A 40-year follow-up.

INTRODUCTION: In this study, we aimed to evaluate the changes in dental arch dimensions, tooth size, and incisor crowding in subjects with normal occlusion over a 40-year period. METHODS: A sample of 82 white subjects with normal occlusion evaluated in adolescence and early adulthood was recruited for a third evaluation in their sixth decade of life. The final sample included dental casts of 22 subjects (12 men, 10 women) obtained at mean ages of 13.3, 17.8, and 60.9 years. The following variables were measured on the digital casts: mesiodistal tooth size; clinical crown height; arch length, width, and perimeter; palatal depth; crowding; overjet; overbite; and curve of Spee. Interphase changes were evaluated using repeated measures analysis of variance, followed by Tukey tests (P <0.05). RESULTS: Increases of clinical crown height in the posterior teeth and incisor crowding were found. Decreases of mesiodistal tooth size, mandibular intercanine width, arch length, arch perimeter, overbite, and curve of Spee were observed. Palatal depth increased from 13 to 17 years of age. No changes were observed for overjet. CONCLUSIONS: Subjects with normal occlusion had changes in tooth size and alignment, overbite, and arch dimensions from adolescence to late adulthood.

Three-dimensional development of the upper dental arch in unilateral cleft lip and palate patients after early neonatal cheiloplasty.

OBJECTIVES: This prospective morphometric study evaluated the growth of the upper dental arch in UCLP patients after early neonatal cheiloplasty and compared the selected dimensions with published data on non-cleft controls and on later operation protocol patients. METHODS: The sample comprised 36 Czech children with nonsyndromic complete UCLP (cUCLP) and 20 Czech children with nonsyndromic incomplete UCLP (UCLP + b). 2-D and 3-D analyses of palatal casts were made at two time points: before neonatal cheiloplasty at the mean age of 3 days (±1 day), and 10 months after surgery at the mean age of 10 months (±1 month). RESULTS: The upper dental arch of cUCLP and UCLP + b patients showed similar developmental changes, but the cleft type influenced growth significantly. The initial high shape variability in cUCLP patients diminished after 10 months, and approached the variability in UCLP + b patients. Both the width and length dimensions increased after surgery. Important growth concerned the anterior ends of both segments. The width and length dimensions illustrated similar growth trends with non-cleft controls and UCLP patients who underwent later cheiloplasty. CONCLUSION: Early neonatal cheiloplasty caused no reduction in the length or width dimensions during the first year of life. Our data suggest a reconstructed lip has a natural formative effect on the actively growing anterior parts of upper dental arch segments, which cause narrowing of the alveolar cleft.

O gênero e a idade influenciam as dimensões do palato duro? Revisão sistemática da literatura / Do gender and age influence hard palate dimensions? A systematic review

RESUMO Objetivo Analisar a influência do gênero e da idade nas dimensões do palato duro, bem como verificar os parâmetros de referência disponíveis na literatura. Estratégia de pesquisa Dois examinadores realizaram a pesquisa de forma independente nas bases de dados Cochrane Library, PubMed-Medline e Web of Knowledge utilizando os descritores de acordo com as regras de sintaxe de cada banco de dados. Critérios de seleção Estudos em humanos observacionais ou experimentais, que avaliaram as dimensões do palato duro ou do arco dentário maxilar com pelo menos uma mensuração no plano transversal, vertical ou sagital em oclusões normais ou más oclusões classe I e que realizaram comparações das dimensões entre os gêneros e/ou idades. Análise de dados Análise descritiva, seguindo subdivisões: delineamento, amostra, instrumentos de avaliação, medidas em milímetros e análise estatística. A qualidade dos estudos incluídos foi verificada através da escala "Newcastle - Ottawa Quality". Resultados Foram selecionados 18 estudos. Destes, 11 apresentaram resultados das dimensões do palato duro ou do arco dentário maxilar conforme o gênero, seis em idade e gênero e um somente em idade. Conclusão As medidas foram maiores no gênero masculino e houve um aumento progressivo nas dimensões do nascimento até o período de dentição permanente.

ABSTRACT Purpose Analyze the influence of gender and age on hard palate dimensions and verify the reference parameters available in the literature. Research strategies Two reviewers independently performed a search at the Cochrane Library, PubMed-Medline and Web of Knowledge databases using descriptors according to the syntax rules of each database. Selection criteria Observational or experimental human studies evaluating the dimensions of the hard palate or maxillary dental arch, with at least one transverse, vertical or sagittal plane measurement, in normal occlusions or class I malocclusions, and comparisons of the dimensions between genders and/or ages. Data analysis Descriptive analysis with the following subdivisions: design, sample, evaluation instruments, measurements in millimeters, and statistical analysis. Quality of the included studies was verified by the Newcastle - Ottawa Quality scale. Results Eighteen studies were selected and 11 presented results for hard palate or maxillary dental arch dimensions according to gender, six in age and gender and one in age only. Conclusion The dimensions were larger in males and progressive increase in the measurements was observed from birth to the permanent dentition period.

Three-dimensional morphology of first molars in relation to ethnicity and the occurrence of cleft lip and palate.

OBJECTIVES: This study aims to describe morphological peculiarities of maxillary and mandibular first molars in Europeans, Asians and Europeans with cleft lip and palate. MATERIAL AND METHODS: Reflex microscopy was used to obtain three-dimensional morphometric landmarks from 40 models (11 Europeans and 13 Asians without cleft lip and palate, 16 Europeans with unilateral cleft lip and palate). The cases were examined using traditional morphometry and geometric morphometry, and visualized using thin-plate splines. RESULTS: Classic morphometry showed no right/left differences in the study groups and no significant differences with regard to the cleft side in patients with cleft lip and palate. In Asians, a significantly greater mesiodistal width was found. Geometric morphometry showed an enlarged centroid size in Asians (maxilla and mandible). In cleft patients, the cleft site did not appear to impact the morphology of first molars. CONCLUSION: Unilateral clefting did not affect the size and shape of molars; however, characteristic ethnicity-based differences were in fact identified. The results are relevant for orthodontic treatment with preadjusted appliances, and prosthetic CAD/CAM restorations.