Vertical facial growth: a longitudinal study from 7 to 14 years of age

Proposed parameters of optimal central incisor positioning in orthodontic treatment planning: A systematic review

OBJECTIVE

Planning of incisal position is crucial for optimal orthodontic treatment outcomes due to its consequences on facial esthetics and occlusion. A systematic summary of the proposed parameters is presented.

METHODS

Studies on Google Scholar©, PubMed©, and Cochrane Library, providing quantitative information on optimal central incisor position were included.

RESULTS

Upper incisors supero-inferior position (4-5 mm to upper lip, 67-73 mm to axial plane through pupils), antero-posterior position (3-4 mm to Nasion-A, 3-6 mm to A-Pogonion, 9-12 mm to true vertical line, 5 mm to A-projection, 9-10 mm to coronal plane through pupils), bucco-lingual angulation (4-7° to occlusal plane perpendicular on models, 20-22° to Nasion-A, 57-58° to upper occlusal plane, 16-20° to coronal plane through pupils, 108-110° to anterior-posterior nasal spine), mesio-distal angulation (5° to occlusal plane perpendicular on models). Lower incisors supero-inferior position (41-48 mm to soft-tissue mandibular plane), antero-posterior position (3-4 mm to Nasion-B, 1-3 mm to A-Pogonion, 12-15 mm to true vertical line, 6-8 mm to coronal plane through pupils), bucco-lingual angulation (1-4° to occlusal plane perpendicular on models, 87-94° to mandibular plane, 68° to Frankfurt plane, 22-25° to Nasion-B, 105° to occlusal plane, 64° to lower occlusal plane, 21° to A-Pogonion), mesio-distal angulation (2° to occlusal plane perpendicular on models).

CONCLUSIONS

Although these findings can provide clinical guideline, they derive from heterogeneous studies in terms of subject characteristics and reference methods. Therefore, the optimal incisal position remains debatable.

Craniofacial growth and SITAR growth curve analysis

BACKGROUND

SITAR (SuperImposition by Translation And Rotation) is a shape invariant growth curve model that effectively summarizes somatic growth in puberty.

AIM

To apply the SITAR model to longitudinal mandibular growth data to clarify its suitability to facial growth analysis.

SUBJECTS AND METHODS

2D-cephalometric data on two mandibular measurements (AP: articulare-pogonion; CP: condylion-pogonion) were selected from the Denver Growth Study, consisting of longitudinal records (age range: 7.9-19.0 years) of females (sample size N: 21; number of radiographs n: 154) and males (N: 18; n: 137). The SITAR mixed effects model estimated, for each measurement and gender separately, a mean growth curve versus chronological age, along with mean age at peak velocity (APV) and peak velocity (PV), plus subject-specific random effects for PV and mean size. The models were also fitted versus Greulich-Pyle bone age.

RESULTS

In males, mean APV occurred at 14.6 years (AP) and 14.4 years (CP), with mean PV 3.1 mm/year (AP) and 3.3 mm/year (CP). In females, APV occurred at 11.6 years (AP and CP), with mean PV 2.3 mm/year (AP) and 2.4 mm/year (CP). The models explained 95-96 per cent of the cross-sectional variance for males and 92-93 per cent for females. The random effects demonstrated standard deviations (SDs) in size of 5.6 mm for males and 3.9 mm for females, and SDs for PV between 0.3 and 0.5 mm/year. The bone age results were similar.

CONCLUSION

The SITAR model is a useful tool to analyse epidemiological craniofacial growth based on cephalometric data and provides an array of information on pubertal mandibular growth and its variance in a concise manner.

Validation of the Vertical Facial Growth Screening Test

Background. Vertical facial growth has a high prevalence. Nonspecialized professionals have shown low sensitivity to identify patients at risk. In the face of this difficulty, we designed and validated a screening checklist for vertical facial growth. Methods. A multidisciplinary team of 5 members developed the Vertical Facial Growth Screening Test. A sample of 160 evaluations was obtained. We consider as the gold standard the evaluation of 2 specialists in dentofacial orthopedics. Results. Consistency measured with Cronbach α was .675 for 10 items. Test-retest reliability was .956. The interobserver concordance was .886. The receiver operating characteristic curve has .987 area under the curve. Conclusion. This is the first study to design and validate a screening checklist for vertical facial growth for nonexpert evaluators. We think that given its good performance, ease of use, inexpensiveness, and availability, the test could be useful for nontrained professionals dealing with children.

Are pediatricians and otolaryngologists well prepared to identify early signs of vertical facial growth?

BACKGROUND

The prevalence of vertical facial growth is very high in the developed world. Most authors agree that mouth breathing is its main cause. Even though care is mainly conducted by odontologists, the professionals who first see these patients are pediatricians and otolaryngologists. The objective of this study is to analyze the ability of pediatricians and otolaryngologists to identify early signs of vertical facial growth among children.

METHODS

60 participant aged 4.1-13.7 years were analyzed subjectively by 9 otolaryngologists, 9 pediatricians and two specialists in dentofacial orthopedics. They were also assessed objectively with cephalometric analysis.

RESULTS

Otolaryngologists showed 34.78% sensitivity, 92.86% specificity and 48.33% efficiency. Pediatricians showed 13.04% sensitivity, 100% specificity and 33.33% efficiency. Using a linear regression model compared against the objective measurements we found a weak positive correlation both for otolaryngologists and pediatricians.

CONCLUSION

The sensitivity was very low for both groups. We believe it is of paramount importance to increase the awareness and the ability of otolaryngologists and pediatricians to recognize signs of disrupt facial growth.

Relationship between periodontal status of mandibular incisors and selected cephalometric parameters : Preliminary results

Purpose

The aim of this cross-sectional study was to evaluate the correlation between the periodontal tissue of mandibular incisors and several dentoalveolar and skeletal cephalometric parameters.

Materials and methods

The sample consisted of 35 patients (mean age 26.42 ± 8.02 years). Eligibility criteria included good overall health status with no history of dental trauma, congenital defects, active periodontal diseases, restorative and prosthetic treatment in the area of the mandibular incisors. Gingival recession width and height (GRW, GRH), gingival thickness (GT), width of keratinized gingiva (WKT) and clinical attachment loss (CAL) were evaluated at 140 lower incisors. Incisors inclination (1-:ML), skeletal class (ANB, WITS), intermaxillary angle (NL:ML) and mandibular symphysis dimensions (symph. length and width) were assessed in cephalograms. Spearman’s correlation coefficient was used for statistical analysis at the P < 0.05 level.

Results

A statistically significant positive moderate correlation was found for GT and WITS and also symph. length. WKT correlated positively with ANB, WITS and symph. length, with moderate strength of the correlation. GRW, GRH and CAL did not correlate with any cephalometric parameters.

Conclusion

The results of this study indicated evidence for an association between WKT and GT and some cephalometric variables—ANB, WITS, and symphysis length.

Variation in timing, duration, intensity, and direction of adolescent growth in the mandible, maxilla, and cranial base: the Fels longitudinal study

There is considerable individual variation in the timing, duration, and intensity of growth that occurs in the craniofacial complex during childhood and adolescence. The purpose of this article is to describe the extent of this variation between traits and between individuals within the Fels Longitudinal Study (FLS). Polynomial multilevel models were used to estimate the ages of onset, peak velocity, and cessation of adolescent growth, the time between these ages, the amount of growth between these ages, and peak velocity. This was done at both the group and individual levels for standard cephalometric measurements of the lengths of the mandible, maxilla, and cranial base, the gonial angle, and the saddle angle. Data are from 293 untreated boys and girls age 4-24 years in the FLS. The timing of the adolescent growth spurt was, in general, not significantly different between the mandible and the maxilla, with each having an earlier age of onset, later age of peak velocity, and later age of cessation of growth as compared to the cranial base length. Compared to lengths, angles had in general later ages of onset, peak velocity, and cessation of growth. Accurate characterization of the ontogenetic trajectories of the traits in the craniofacial complex is critical for both clinicians seeking to optimize treatment timing and anatomists interested in examining heterochrony.

Estudo das características cefalométricas em adolescentes brasileiros portadores de Padrão Face Longa

OBJETIVO: definir valores cefalométricos esqueléticos e dentários para adolescentes brasileiros com Padrão Face Longa. MÉTODOS: a amostra foi constituída de telerradiografias em norma lateral de 30 pacientes com Face Longa, sendo 17 do sexo feminino e 13 do masculino; e 30 pacientes face Padrão I, 15 do sexo masculino e 15 do feminino, no estágio de dentadura permanente durante a adolescência. As características do Padrão Face Longa foram definidas clinicamente, pela análise facial. As seguintes grandezas cefalométricas foram avaliadas: (1) Comportamento sagital das bases apicais (SNA, SNB, ANB, NAP, Co-A, Co-Gn); (2) Comportamento vertical das bases apicais (SN.PP, SN.PM, ângulo goníaco, AFAT, AFAI, AFAM, AFP, AFATperp, AFAIperp); (3) Comportamento dentoalveolar (1-PP, 6-PP, 1-PM, 6-PM, 1.PP, IMPA); e (4) Proporção entre as alturas faciais (AFAIPerp/AFATPerp, AFAI/AFAT, AFAM/AFAI). RESULTADOS E CONCLUSÕES: o erro vertical na Face Longa concentra-se no terço inferior. A maxila apresenta uma maior altura dentoalveolar e a mandíbula, com morfologia mais vertical, mostra maior rotação no sentido horário. Essas características morfológicas e espaciais acarretam alterações sagitais e verticais no esqueleto e alterações verticais dentoalveolares. No sentido sagital, os ângulos de convexidade facial estão aumentados. No sentido vertical, as alturas faciais anteriores total e inferior estão aumentadas. O componente dentoalveolar está mais longo.

Age-dependant cephalometric standards as determined by multilevel modeling

INTRODUCTION

The purpose of this study was to evaluate the feasibility of constructing age-dependant cephalometric standards for white subjects by using 3 data sets.

METHODS

The data sets were the samples from the Fels Longitudinal Study (United States), the Michigan Growth Study (United States), and the Nijmegen Growth Study (The Netherlands). The 3 mixed-longitudinal samples provided data for 218 girls and 231 boys between 9 and 14 years of age and were compared based on 4 cephalometric angles: SNA, SNB, ANB, and SN/GoMe. Curve-fitting and statistical comparisons were performed with multilevel modeling procedures.

RESULTS

All 4 angles showed linear changes over time. SNA and SNB increased, whereas ANB and SN/GoMe decreased. Based on paired-sample comparisons, the samples displayed statistically significant (P <0.05) differences for 50% of the growth velocities and 8% to 17% of the intercepts (size of the angle at 11 years). The SNA and SNB angles showed small and inconsistent differences across the samples. The ANB angle for the Fels boys decreased less than in the other 2 samples. The Nijmegen and Fels girls had the greatest and the least decreases, respectively, in the SN/GoMe angle. Most sample differences decreased over time.

CONCLUSIONS

Based on the growth differences identified, we concluded that sagittal and vertical jaw relationships have different patterns of growth in different samples of white subjects; indiscriminate pooling of data, to create age-dependant cephalometric standards for white subjects is not recommended.

A comparison of human jaw muscle cross-sectional area and volume in long- and short-face subjects, using MRI

OBJECTIVE

In humans, the vertical craniofacial dimensions vary significantly with the size of the jaw muscles, which are regarded as important controlling factors of craniofacial growth. The functional relevance of the maximum cross-sectional area (CSA), indicating maximum muscle strength, is questionable since peak forces are generated only a fraction of the day. Alternatively, muscle volume (indicating the generated loads) might be a more meaningful functional variable. Therefore, the aim of this study was to investigate if jaw muscle volume is stronger related with vertical craniofacial dimensions than with jaw muscle CSA.

DESIGN

Thirty-one adult healthy subjects with varying vertical craniofacial morphology participated in this study. Axial magnetic resonance imaging (MRI) scans were used for segmentation of the masseter (Mas) and medial pterygoid muscles (MPM). This enabled measurements of the muscle CSA and volume. Cephalometric analysis was performed using lateral radiographs. With factor analysis, the number of cephalometric variables was reduced into two factors that represented the anterior face height and the posterior face height (PFH), respectively. Subsequently, mutual relationships between these factors and muscular variables were assessed using a multiple regression analysis.

RESULTS

It was found that vertical craniofacial dimensions were significantly better (up to 12%) related with muscle volume rather than with CSA. Furthermore, it was shown that especially the PFH factor was significantly correlated with the Mas and MPM.

CONCLUSION

Vertical craniofacial dimensions are stronger related with jaw muscle volume than with CSA. Tentatively, it can be assumed that the generated muscle loads, rather than maximum forces, influence vertical craniofacial growth.

Changes in condylar path inclination during maximum protrusion between the ages of 6 and 12 years

The purpose of this study is to quantify the changes in sagittal condylar path inclination during mandibular protrusion between the ages of 6 and 12 years. A total of 172 children (82 males and 90 females) ranging in age from 6.5 to 12.9 years were divided according to their chronological age into five subgroups with mean ages of 7.1, 8, 9, 10 and 11.4 years respectively. The control group consisted of 41 adults with a mean age of 28 years. All subjects had a normal temporomandibular joint function and neutral occlusion. Five maximum protrusion-retrusion movements were recorded with six degrees of freedom in each subject using an ultrasound (JMA) jaw-tracking system. Initially, condylar path inclination angle (CPIA) was calculated stepwise for each millimetre distance, for the first 10 mm of protrusive tracing path on both sides. A single mean value was then assigned for the entire protrusive path. One-way analysis of variance proved to be significant among the five subgroups of children. Linear regression analysis showed that condylar path had a tendency to become steeper with age, although it was statistically weak. The data indicated that the mean CPIA is 43 degrees -44 degrees at the age of seven, increases annually by 1.2 degrees -1.3 degrees and reaches an average of 49 degrees -50 degrees by the age of 12 at which time it attains around 83-85% of its adult level. In subgroup V, the female population had significantly steeper condylar path on the left-hand side than the male population. Condylar path inclinations indicated a symmetrical growth pattern of the articular eminence.

Características cefalométricas do Padrão Face Longa: considerando o dimorfismo sexual

OBJETIVO: o presente estudo avaliou a hipótese de variação das características cefalométricas de acordo com o gênero para portadores de Padrão Face Longa. METODOLOGIA: foi analisado um total de 73 telerradiografias em norma lateral, sendo 34 Padrão Face Longa e 39 Padrão I (grupo controle), selecionadas com base na morfologia facial, sem considerar as relações oclusais. Foram avaliados: padrão de crescimento facial, alturas faciais anteriores e posterior, relação maxilomandibular, além das relações dentárias com suas bases apicais. RESULTADOS: o grupo controle (Padrão I) apresentou dimorfismo (p<0,001) no comprimento efetivo da maxila e da mandíbula, além das alturas faciais avaliadas. Foram significantes também (p<0,05) as proporções entre as alturas faciais e as distâncias entre os incisivos e molares em relação aos planos palatino e mandibular. Para os portadores de Padrão Face Longa, as mesmas variáveis cefalométricas não mostraram diferenças significantes entre os gêneros (p>0,05), exceto os comprimentos efetivos da maxila e da mandíbula, além da altura facial anterior inferior e posterior (p<0,05). CONCLUSÕES: concluiu-se que enquanto ocorreu dimorfismo nos indivíduos Padrão I, para as estruturas influenciadas pela diferença no tamanho esquelético entre os gêneros, isso não aconteceu nos portadores de Padrão Face Longa. Essa maior similaridade entre os gêneros provavelmente ocorreu porque a deformidade, mais grave no gênero feminino, foi suficiente para anular o menor tamanho esquelético esperado para estes indivíduos.

Proposta para classificação, segundo a severidade, dos indivíduos portadores de más oclusões do Padrão Face Longa

OBJETIVO: o presente estudo teve como objetivo propor um método para classificação, segundo a severidade, dos indivíduos Padrão Face Longa, avaliando sua confiabilidade e reprodutibilidade. METODOLOGIA: foram utilizadas fotografias faciais (frontal, perfil e frontal sorrindo) de 125 crianças Padrão Face Longa (54 do gênero feminino e 71 do gênero masculino), selecionadas apenas considerando-se a morfologia facial, com idades entre 10 anos e 6 meses e 15 anos e 2 meses. As fotografias foram avaliadas, separadamente, por três examinadores, sendo reavaliadas após três semanas, em uma nova disposição aleatória. Os indivíduos foram graduados em três subtipos, de acordo com a severidade: moderado, médio e severo. Para avaliar as concordâncias intra e interexaminadores, foi utilizada a estatística Kappa (k). RESULTADOS: na avaliação intra-examinador, todos os examinadores obtiveram concordâncias substanciais, com o valor de Kappa variando de 0,64 a 0,66, havendo em todos os examinadores 80% ou mais de concordância. Quando comparadas as avaliações interexaminadores, as freqüências de concordância diminuíram, variando de 67,2% a 70,4%. A partir dos valores de Kappa, que variaram de 0,41 a 0,46, a interpretação foi considerada moderada. CONCLUSÕES: com base nesses resultados, o método foi considerado aplicável, com necessidade de complemento de informações provenientes de outros exames rotineiramente aplicados em Ortodontia. A aplicação clínica será demonstrada com intuito de evidenciar os níveis diferentes de severidade das más oclusões do Padrão Face Longa e as características do protocolo de tratamento recomendado.

Development and testing of multilevel models for longitudinal craniofacial growth prediction

INTRODUCTION

The aims of this study were to (1) develop longitudinal growth curves that would allow individual variations to be accurately modeled and (2) use these models to predict craniofacial growth changes in children with varying amounts of longitudinal data available.

METHODS

Based on a sample of 159 girls (994 cephalograms) and 128 boys (947 cephalograms), multilevel population models were derived. Polynomial models of the population's growth curve were derived for the measurements MPA, Me-X, Me-theta, Me-Y, and Me-R. Angular and horizontal measures (MPA, Me-X, and Me-theta) were described by simpler, second-order models, and vertical measures (Me-Y and Me-R) were described by more complex, fifth-order models.

RESULTS

Decreases in MPA during childhood and increases in Me-theta during adolescence could be explained by the relative contributions of the horizontal (Me-X) and vertical (Me-Y) movements of menton. There was greater anterior movement of menton during childhood and greater inferior movement during the adolescent growth spurt. By using varying numbers of longitudinal cephalograms between 6 and 10 years of age, the models were used to predict subjects' craniofacial growth changes from ages 10 to 15. Based on correlations, root mean squared error, and percent accuracy, individual growth predictions for the various measures were found to be highly accurate on an independent subsample drawn from the larger sample and on an independent validation sample. Correlations between predicted and actual values on the sample used to develop the models ranged from 0.81 to 0.95. Accuracy was best for the measurements that changed the most during the prediction period (Me-Y and Me-R), with accuracies between 83% and 90%. More longitudinal data did not increase the predictive accuracy for all measurements. The models that were least accurate (Me-X, MPA, and Me-theta) showed the greatest improvement in prediction accuracy with more longitudinal data. These improvements ranged from 1.6% to 15%.

CONCLUSIONS

Longitudinal growth curves based on multilevel procedures can accurately describe population and individual growth curves, and 5-year predictions with this method are highly accurate and externally valid.

Características cefalométricas do padrão face longa

Este estudo determinou as características cefalométricas dos indivíduos portadores de Padrão Face Longa em comparação com indivíduos Padrão I. Um total de 73 telerradiografias em norma lateral, sendo 34 Padrão Face Longa e 39 Padrão I, foram selecionadas com base na morfologia facial, não considerando as relações oclusais e sagitais. Foram avaliados: padrão de crescimento facial, alturas faciais anteriores e posterior, relação maxilo-mandibular, além das relações dentárias com suas bases apicais. De uma forma geral, os indivíduos Padrão Face Longa apresentaram grandes desvios em relação aos indivíduos Padrão I, sendo a doença decorrente de um desequilíbrio entre os componentes verticais. Pôde-se observar que os valores das grandezas AFAT, AFAI, AFATperp, AFAIperp, 1-PP, 6-PP, 1-PM, SNB, ANB, ângulo goníaco, ângulo plano mandibular, além das proporções AFAI/AFAT e AFAIperp/AFATperp, estavam significantemente alterados para os indivíduos Padrão Face Longa. Com base nos resultados obtidos neste estudo, verificou-se que esses indivíduos caracterizavam-se pelo padrão de crescimento vertical e por um aumento da altura facial anterior inferior - conseqüentemente, da altura facial anterior total - estando a deformidade localizada abaixo do plano palatino. Foram observados ainda um retrognatismo maxilar e mandibular, além da presença de extrusão dentária anterior (superior e inferior) e póstero-superior, com os incisivos superiores bem posicionados em suas bases e os inferiores lingualizados.

Three-dimensional facial growth studied by optical surface scanning

The objective of the investigation was to study the three-dimensional growth of the face, and to examine the hypothesis that there are three-dimensional differences between the faces of boys and girls. The subjects comprised 132 British Caucasians aged 5-10 years measured by optical surface scanning in this cross-sectional study. Average scans for each age and sex subgroup were superimposed to assess the differences with age and sex. Males were generally larger than females. The greatest difference was between the facial heights and the least in the mid-facial dimensions. The face height of both sexes increased by an average of 3-4 mm annually. Mid-face prominence and width altered little. Mandibular width increased by 1-3 mm a year, rising to 3-5 mm in some years at the inferior areas of the mandibular region. Mandibular prominence also increased. Nose height and prominence and alar base width increased by 2 mm per year on average. Dorsum width changed little. Boys were generally larger than girls. Growth in facial height was greatest. Mid-face prominence and width changed little with age, whilst the prominence and width of the lower face increased more. Nasal prominence and alar base width increased at most ages. Dimensions changed more than reported by cephalometric studies, possibly as this study included the soft tissues. Refereed Scientific Paper