Craniofacial Growth Changes Research Articles

Medium-term effects of rapid maxillary expansion on nasal cavity and pharyngeal airway volumes considering age as a factor: A retrospective study

ObjectivesThe medium-term effects of rapid maxillary expansion (RME) on nasal cavity (NC) and upper airway (UA) dimensions based on chronological age are still unclear. This retrospective study evaluated the medium-term changes occurring in the NC and pharyngeal airways (PA) after RME in two distinct age-based cohorts of patients. MethodsThis retrospective study included 48 subjects who underwent RME grouped in two cohorts: a 6–9-year-old group (EEG group: early expansion group - 25 subjects) and an 11–14-year-old group (LEG group: late expansion group - 23 subjects). NC and PA volumes were analyzed from CBCT imaging segmentation before RME (T0) and twelve months after RME (T1). The amount of maxillary expansion (PW) and minimal cross-sectional area (CSmin) were also considered. ResultsAll PAs’ volumetric sub-regions, CSmin and PW showed a significant volumetric increment (p < 0.05). Inter-group comparisons showed significant differences (p < 0.05) for nasopharynx and CSmin parameters (p < 0.05), while no significant changes were recorded for the other UA's sub-regions and PW (p > 0.05). According to a deviation analysis, part of the UA increase (more marked for the nasopharynx area) may have occurred due to reduced adenotonsillar tissues, which were larger in the EEG group. ConclusionsTwelve months after treatment, clinicians should not expect changes in the UAs dimensions to be solely related to treatment effects of RME; instead, normal craniofacial growth changes and spontaneous regression of the adenotonsillar tissue could represent the most significant factors influencing UAs changes. Clinical SignificanceFrom the clinical perspective, the results of the present study encourage caution when considering the therapeutic effects of RME on airways dimensions.

Outcome assessment of orthodontic clear aligner vs fixed appliance treatment in adolescents with moderate to severe malocclusions.

To compare the efficacy and efficiency of treatment with clear aligners (CAT) vs fixed appliances (FAT) in adolescents with Class I and II moderate to severe malocclusions. One operator's (Garfinkle) cases from 2014 to 2019, started at age 12-18 years, with pre- and posttreatment records were identified and used according to an institutional review board-approved protocol. Records were measured by two calibrated, blinded investigators, aided by software (OrthoCAD [Cadent, Fairview, N.J.], Dolphin Imaging & Management Solutions [Chatsworth, Calif]). Discrepancy index (DI) and cast radiograph evaluation (CRE) scores, treatment duration, number of scheduled and emergency visits, and reported appliance and interarch elastic wear compliance were compared between groups using Wilcoxon rank sum and Fisher's exact tests. Cephalometric superimpositions were completed to evaluate craniofacial growth and dental changes. Records from 72 cases met the criteria and were included. For the 47 CAT and 25 FAT cases, mean DI (21 ± 5 and 24 ± 8, respectively; P = .20) and CRE (35 ± 10 and 34 ± 9, respectively; P = .90) scores were not significantly different. Other case attributes and reported appliance and interarch elastic wear compliance were also not significantly different. CAT vs FAT cases had significantly smaller treatment durations (24 ± 6 vs 27 ± 5 months; P = .01) and visit numbers (16 ± 5 vs 24 ± 4; P < .01), but emergency visit numbers were not significantly different (2 ± 2 vs 3 ± 2; P = .08). In adolescents with Class I and II malocclusions and moderate to severe DI scores, on average, CAT vs FAT cases were completed 3 months faster with eight fewer visits, but treatment efficacy was not significantly different.

Morphometric assessment of the sella turcica in different morphologic types of Class II malocclusion: a retrospective study

Objectives: Sella turcica is a substantial anatomic reference structure used to assess craniofacial growth and treatment changes in orthodontics. The aim of this retrospective study was to analyze the size and morphology of sella turcica in different subdivisions of Class II malocclusion and to compare it Class I craniofacial development. Materials and Methods: The study was conducted with 150 patient’s pre-treatment lateral cephalometric radiographs. Good-quality lateral cephalometric radiographs with a prominent appearance of sella turcica were grouped into Class II division 1, Class II division 2 and Class I (control group). On lateral cephalograms, the length, diameter and depth of the sella turcica were gauged and morphological types of the sella turcica was detected. For statistical analysis, one-way ANOVA, Kruskal Wallis analysis with Dunn-Bonferroni test and Chi-square test were used (p <0.05). Results: A significant difference was found in the length of the sella turcica in the Class II div 2 group (p <0.05) compared to the other groups. The differences in depth and diameter of the sella turcica among three groups were non-significant (p > 0.05). The appearance of the sella turcica was normal shaped in most of the subjects (60.6%). Conclusion: No significant difference was found among skeletal Class II division 1, Class II division 2 and Class I groups in terms of diameter and depth of the sella turcica. A smaller length of sella turcica was found in patients with Class II division 2 anomaly.

A Superimposition-Based Cephalometric Method to Quantitate Craniofacial Changes.

To assess the craniofacial changes related to growth and/or to orthodontic and orthognathic treatments, it is necessary to superimpose serial radiographs on stable structures. However, conventional superimposition provides only a graphical illustration of these changes. To increase the precision of growth and treatment evaluations, it is desirable to quantitate these craniofacial changes. The aims of this study were to (1) evaluate a superimposition-based cephalometric method to process numerical data for craniofacial growth changes and (2) identify a valid, reliable, and feasible method for superimposition. Forty pairs of cephalograms were analyzed at T1 and T2 (mean age 9.9 and 15.0 years, respectively). The superimposition-based cephalometric method involved relating the sagittal and vertical measurements on the T2 radiographs to the nasion and sella landmarks on the T1 radiographs. Validity and reliability were evaluated for three superimposition methods: the sella-nasion (SN); the tuberculum sella-wing (TW); and Björk’s structural. Superimposition-based cephalometrics can be used to quantify craniofacial changes digitally. The numerical data from the superimposition-based cephalometrics reflected a graphical illustration of superimposition and differed significantly from the data acquired through conventional cephalometrics. Superimposition using the TW method is recommended as it is valid, reliable, and feasible.

First Systematic Documentation of Sex Differences in Craniofacial Norms of Nigerian Children

Datasets containing standardized craniofacial measurements in African children are not widely available. Such datasets are needed to establish craniofacial norms and document patterns of normal growth, which are often population specific. In this cross‐sectional study we used traditional calipers to collect 13 standard anthropometric measurements on 320 male (n=172) and female (n=148) children from Sokoto, Nigeria with mean age of 38.39 and 37.34 months, respectively. The study participants were divided into eight different age groups: 6–12; 12–18; 18–24; 24–30; 30–36; 36–48; 48–60 and 60–72 months. ANOVA was used to test for sex differences within the age groups. Our results revealed statistically significant sex differences in craniofacial morphology at each age group, except the 12–18 month old subset. The greatest number of sexually dimorphic measures was observed in the 30–36 month and 36–48 month age groups. Through 60 months, the means of measurements that showed significant sex differences were universally larger in females than in males. By the 60–72 month group, mean values for sexually dimorphic traits were larger in males. This is consistent with reports in other cohorts showing a more accelerated rate of craniofacial growth in females during early postnatal growth that begins to level off during childhood. This study provides the first systematic documentation of sex differences in craniofacial variation in typical growing Nigerian children, increasing our understanding of craniofacial growth changes across different age groups in relation to sexual dimorphism. This information can be used by Nigerian clinicians and other health care givers to further understand craniofacial growth and morphology of Nigerian children, and serves as baseline data for the creation of a local craniofacial database that will facilitate diagnosis of craniofacial anomalies and overall patient management.Support or Funding InformationThe author(s) hereby acknowledge the support of the American Association of Anatomists (AAA) through the Short‐term Visiting Scholarship Award to the Laboratory of Dr. J.T. Richtsmeier, Pennsylvania State University, PA, USA as well as the Management of the Usmanu Danfodiyo University, Sokoto, for the Staff Training and Development Fellowship Approval/Award (TETFund).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Longitudinal Sleep Outcomes in Neonates With Pierre Robin Sequence Treated Conservatively.

Although Pierre Robin sequence (PRS) is a major cause of neonatal obstructive sleep apnea (OSA), longitudinal studies reporting evolution with age are lacking. This study aimed to describe changes in sleep-related respiratory parameters and sleep architecture in neonates with PRS treated conservatively (defined for this paper as treatment without tracheostomy or mandibular distraction). A retrospective, 14-year, single-institution study of neonates with PRS who underwent diagnostic polysomnography (PSG) and at least one follow-up PSG. Those treated with surgery were excluded. Data were analyzed using a mixed-effects model with subject-specific random effect. In a cohort of 21 infants, baseline PSG (mean age 0.9 ± 0.7 months) showed a total apnea-hypopnea index (AHI) of 24.3 ± 3.6 events/h, obstructive apnea-hypopnea index (OAHI) of 13.4 ± 1.6 events/h, central apnea index of 10.2 ± 3.2 events/h, and an arousal index of 28.3 ± 1.3 events/h (variables reported as least square means ± standard error of the mean). There was a significant reduction in AHI, OAHI, arousal index, and percentage of REM sleep with advancing age. Although 71% of infants achieved full oral feeds by one month of age, some infants remained underweight during infancy. These neonates with PRS and OSA, treated conservatively, had an improvement in OAHI with advancing age with the median age of OSA resolution at 15 months. Factors potentially responsible include craniofacial growth and maturational changes of respiratory control. Further studies are necessary to determine the long-term effects of conservative management on growth and neurodevelopmental outcomes in these infants.

Impact of breathing patterns on the quality of life of 9- to 10-year-old schoolchildren.

Mouth breathing can cause a set of changes in craniofacial growth and development, with esthetic, functional, and psychological repercussions. To determine the impact of mouth breathing on the quality of life of schoolchildren. A school-based, cross-sectional study was conducted with 1911 children ages 9 and 10 years in the city of Recife, Brazil. The children answered the Mouth Breather Quality of Life questionnaire and a questionnaire that addressed sociodemographic data and health-related aspects. Clinical examinations were performed by an examiner who had undergone a training and calibration process for the diagnosis of mouth breathing (kappa = 0.90). Descriptive statistics were conducted to characterize the sample. Statistical analysis involved the Student's t-test and the F test (analysis of variance) (alpha = 5%). The prevalence of mouth breathing was 54.81%. Children with oral breathing demonstrated a poorer quality of life in comparison with children with nasal breathing (p < 0.001). The following variables were significantly associated with a poorer quality of life among the children with mouth breathing: a younger age (p < 0.001) and the use of medication (p = 0.002). Based on the present findings, children with the mouth-breathing pattern experience a greater negative impact on quality of life in comparison with those with the nose-breathing pattern. Thus, the early diagnosis and treatment of this clinical condition are fundamental to minimizing the consequences of mouth breathing on the quality of life of schoolchildren with respiration disorders.

Age- and sex-related growth patterns of the craniofacial complex in European children aged 3–6 years

Background: Craniofacial growth changes in young children are not yet completely understood. Up-to-date references for craniofacial measurements are crucial for clinical assessment of orthodontic anomalies, craniofacial abnormalities and subsequent planning of interventions.Aim: To provide normal reference data and to identify growth patterns for craniofacial dimensions of European boys and girls aged 3–6 years.Subjects and methods: Using standard anthropometric methodology, body weight, body height and 23 craniofacial measurements were acquired for a cross-sectional sample of 681 healthy children (362 boys and 319 girls) aged 3–6 years from Germany, Italy and Lithuania. Descriptive statistics, correlation coefficients, percentage annual changes and percentage growth rates were used to analyse the dataset.Results: Between the ages of 3–6 years, craniofacial measurements showed age- and sex-related patterns independent from patterns observed for body weight and body height. Sex-related differences were observed in the majority of craniofacial measurements. In both sexes, face heights and face depths showed the strongest correlation with age. Growth patterns differed by craniofacial measurement and can be summarised into eight distinct age- and sex-related patterns.Conclusion: This study provided reference data and identified sex- and age-related growth patterns of the craniofacial complex of young European children, which may be used for detailed assessment of normal growth in paediatrics, maxillofacial reconstructive surgery and possibly for forensic age assessment.

Evaluation of craniofacial growth changes in subjects with class II and class III malocclusions during the circum-pubertal period

Evaluation of craniofacial growth changes in subjects with class II and class III malocclusions during the circum-pubertal period

Three-dimensional longitudinal changes in craniofacial growth in untreated hemifacial microsomia patients with cone-beam computed tomography

The purpose of this study was to evaluate the concept that the affected and contralateral sides do not grow at the same rate in patients with hemifacial microsomia. Changes in the cranial base, maxilla, mandible, and occlusal plane were evaluated on 3-dimensional images from cone-beam computed tomography data in untreated patients. Six patients were classified as having mandibular Pruzansky/Kaban type I, IIA, or IIB hemifacial microsomia. Cone-beam computed tomography (MercuRay; Hitachi, Tokyo, Japan) scans were taken before orthodontic treatment during both growth and postpuberty periods. The cranial base as defined by the position of the mastoid process was in a different position between the affected and contralateral control sides. The nasomaxillary length or height was shorter on the affected side for all 6 patients with hemifacial microsomia regardless of its severity, and it grew less than on the contralateral control side in 5 of the 6 patients. The occlusal plane angle became more inclined in 4 of the 6 patients. The mandibular ramus was shorter on the affected side in all patients and grew less on the affected side in 5 of the 6 patients. The mandibular body grew slower, the same, or faster than on the control side. The cranial base, position of the condyle, lengths of the condyle and ramus, and positions of the gonial angle and condyle can vary between the affected and contralateral control sides of patients with hemifacial microsomia, with the ramus and nasomaxillary length usually growing slower than they grow on the control side. These results suggest that many factors affect the growth rate of the craniofacial region and, specifically, the mandible in patients with hemifacial microsomia.

Changes in longitudinal craniofacial growth in subjects with normal occlusions using the Ricketts analysis

ObjectiveThis study was designed to define the Korean norm values for the Ricketts analysis.MethodsIn this longitudinal study, lateral cephalograms of 31 subjects with normal occlusion were taken biennially from ages 9-19 years. Cephalometric measurements were performed. Parameters for which the 10-year change did not exceed one standard deviation were defined as unchanged. The means and standard deviations for the measured parameters were determined for each age group.ResultsNo significant changes in growth were observed in the molar relationship, incisor overjet, incisor overbite, mandibular incisor extrusion, interincisor angle, lower incisor tip (B1) to A point-Pogonion (A-PO) plane, upper incisor tip (A1) to A-PO plane, B1 inclination to A-PO, A1 inclination to A-PO, B1 inclination to Frankfurt plane (FH), convexity, lower facial height, facial axis, maxillary depth, maxillary height, palatal plane to FH, cranial deflection, ramus Xi position, or porion location. Continual changes over the 10 years of growth were observed in the maxillary first molar distal position to pterygoid true vertical plane, facial depth, mandibular plane to FH, anterior cranial length, mandibular arc, and corpus length.ConclusionsClinicians can apply the Korean norms at age 9 as determined in this study when using the Ricketts analysis. The patient's age at the beginning of treatment and their sex should be taken into consideration when drawing visual treatment objectives.

Craniofacial growth changes and dental attrition in the primary dentition

Presence of pronounced incisal and occlusal wear in primary dentition is fairly common in children. Several factors are implied, however, the possible correlation of craniofacial growth to the occurrence of severe incisal tooth wear in children has not been described to date. Thus, this study was aimed to find any association between the craniofacial growth changes and the occurrence of severe incisal wear in children. Twenty-seven sets of series of dental casts and corresponding lateral cephalograms are selected from the archive of Pediatric Dentistry, Department of Tokyo Medical and Dental University Hospital. Samples were divided into two groups based on the extent of incisal wear observed on the primary maxillary anterior teeth: slight attrition (N = 13) and severe attrition (n = 14) groups. Lateral cephalograms at early deciduous dentition at T1 (3.5 ± 0.6 years old) and late deciduous dentition at T2 (6.2 ± 0.6 years old) were manually traced and 17 linear and 22 angular measurements were measured with analyzing software (WinCeph ver.9). Annual growth rate for each sample was calculated to determine any significant difference between samples from two groups. Significant horizontal growth of the mandible with both the reduction of anterior tooth height and increase of posterior tooth height were found in the severe attrition group. Reduction of upper incisor angle to FH plane and upper dental arch length were also related with the attrition of teeth. The incisal tooth wear of deciduous teeth was significantly associated with the craniofacial growth changes.

Craniofacial growth changes and dental attrition in the primary dentition

Craniofacial growth changes and dental attrition in the primary dentition

Vertical craniofacial growth changes in French-Canadians between 10 and 15 years of age

Because of limited available reference data, this study described the vertical growth changes that occur in untreated adolescents 10 to 15 years of age and evaluated the validity of measurements commonly used to classify patients' vertical growth tendencies. The sample consisted of 228 subjects (119 boys, 109 girls) between 10 and 15 years of age with normal occlusions or malocclusions who had lateral cephalograms (n = 1303) taken annually. Based on 6 landmarks, 3 angles (PPA, MPA, PP/MPA) and 2 proportions (PFH:AFH and UFH:LFH) were calculated. To reduce errors, each subject's growth curve was estimated by using multilevel modeling procedures, and the estimated values were analyzed. Growth changes between 10 and 15 years for each of the 5 measurements followed relatively simple (linear or quadratic) polynomial models. On average, PPA and PFH:AFH increased, and MPA and PP/MPA decreased. The UFH:LFH ratio increased during the first few years and then decreased. MPA, PP/MPA, and PFH:AFH showed moderately high intercorrelations; PPA displayed moderate to moderately low correlations with UFH:LFH; UFH:LFH showed a moderate correlation with PP/MPA. Approximately 75% to 86% of the subjects classified as hyperdivergent or hypodivergent at 10 years maintained their classification. Subjects classified as hyperdivergent at 15 years of age showed significantly greater growth changes than did those classified within normal limits, who, in turn, showed greater changes than did the hypodivergent subjects. Measurements typically used to classify vertical growth tendencies changed significantly during adolescence, with boys generally showing greater changes than girls. Although MPA, PFH:AFH, and PP/MPA measured the same phenotypic attribute, PPA and UFH:LFH were relatively independent of the other 3 measurements. Most subjects maintained their vertical facial types, but some worsened, and others improved.

Intrinsic Effects of Congenital Cleft Palate on Craniofacial Morphology and Growth Characteristics in Puberty

Of the 12 children in prepuberty (then aged 9 years) with unoperated submucous cleft palate where we previously found a characteristic morphology of the maxilla, we examined changes in the maxillary morphology in their puberty (until age 14 years), aiming to determine the intrinsic effects of congenital cleft palate on their craniofacial morphology and growth characteristics, which also involve the formation of cranioface, by retrospectively comparing their findings and those of noncleft children with normal occlusion. Twelve Japanese children (7 girls and 5 boys) with unoperated submucous cleft palate at age 14 years were examined cephalometrically. None of them had undergone dentofacial orthopedic treatment of the maxilla. Their craniofacial morphologic characteristics were compared with those of 60 Japanese noncleft children aged 14 years (30 girls and 30 boys) with normal occlusion. The results were nearly identical to the previous findings when they were 9 years old: the maxillary length was short, the anterior part of the maxilla being retruded and the posterior part of the maxilla being in anterior position in the cleft children at age 14 years, compared with the noncleft children. In the craniofacial growth changes between the ages 9 and 14 years, an increase in the posterior upper facial height was markedly small, and the inclination of the palatal plane was promoted in the cleft children, compared with the noncleft children. We confirmed that the intrinsic effects of congenital cleft were influential on the morphology of cranioface and its growth changes, which also involve craniofacial formation.

顎変形症患者における脊椎側彎症と顎顔面形態異常および顎関節症との関連性

Idiopathic scoliosis is a well-known orthopedic disease in childhood and the onset and progress are observed during adolescence. It is speculated that the progress of idiopathic scoliosis affects the maxillofacial growth and the function of the temporomandibular joint because the craniofacial skeletal is located on the top of the spinal column. Another reason may be that asymmetric craniofacial growth changes the head posture and/or spinal column. In this study, we examined the association of scoliosis with jaw deformity and temporomandibular joint disorders.The subjects were 44 patients who underwent orthognathic surgery for treatment of a jaw deformity at Hiroshima University Hospital. We measured the Cobb angle, an indicator of scoliosis, and the curve of the spinal column in vertebrae thoracicae on the chest radiograph. Moreover, the lateral shift of points A and B, cant of the occlusal plane and ANB angle were measured on the postero-anterior (PA) plane and lateral cephalograms. Association between the curve of the spinal column and maxillofacial morphology was examined by correlation analysis. The degree of scoliosis was examined in association with the pathological status of temporomandibular joint.The prevalence of subjects diagnosed with scoliosis was 22.7%. Among the scoliosis patients, 70% were female. In all subjects with a jaw deformity, a significantly positive correlation was not found between the following variables and the Cobb angle: ANB angle, lateral shift of points A and B, cant of the occlusal plane. Moreover, no significant association between the curve of spinal column in the vertebrae thoracicae and previous variables was revealed. In addition, there was no relationship between the degree of the scoliosis and progress of the temporomandibular joint disorder.These findings suggested that the progress of scoliosis exerts no substantial influence on the growth of the maxillofacial skeleton and the progress of temporomandibular joint disorders.

Semilongitudinal cephalometric study of craniofacial growth in untreated Class III malocclusion

Class III growth in white subjects is poorly characterized because of the low prevalence of the disharmony and the clinical tendency to treat this condition early. The purpose of this study was to investigate craniofacial growth changes by using longitudinal cephalometric records of white subjects with untreated Class III malocclusions to provide comparison data for studies of Class III treatment outcomes. Longitudinal records of 103 subjects were analyzed. Annual incremental growth changes in craniofacial variables from early childhood to late adolescence were examined for each sex. Inferential statistics were applied to changes in mandibular length, midfacial length, and lower anterior facial height of each sex (Wilcoxon tests) and between sexes (Mann-Whitney U tests). In the girls, the adolescent spurt in mandibular growth occurred between the ages of 10 and 12 years. In the boys, the adolescent mandibular growth spurt was between 12 and 15 years. Statistically significant growth changes in the average increments of growth of these linear measurements occurred in both sexes between 12 and 15 years. Adolescent peaks in midfacial growth were at prepubertal ages in both sexes. During childhood (5-7 years), much craniofacial growth occurred. Moreover, there was considerable mandibular growth relative to the maxilla in Class III subjects after the adolescent growth spurt. White Class III subjects showed definite worsening of the relative mandibular prognathism and sagittal skeletal discrepancy between the jaws with growth. The growth pattern of 3 fundamental cephalometric measurements (lower anterior face height, midfacial length, and mandibular length) exhibited differences between Class III male and female subjects in both the timing and the size of average growth increments in the adolescent growth spurt.

Editor's Summary and Q&A: Semilongitudinal cephalometric study of craniofacial growth in untreated Class III malocclusion

<h3>Introduction</h3> Class III growth in white subjects is poorly characterized because of the low prevalence of the disharmony and the clinical tendency to treat this condition early. The purpose of this study was to investigate craniofacial growth changes by using longitudinal cephalometric records of white subjects with untreated Class III malocclusions to provide comparison data for studies of Class III treatment outcomes. <h3>Methods</h3> Longitudinal records of 103 subjects were analyzed. Annual incremental growth changes in craniofacial variables from early childhood to late adolescence were examined for each sex. Inferential statistics were applied to changes in mandibular length, midfacial length, and lower anterior facial height of each sex (Wilcoxon tests) and between sexes (Mann-Whitney U tests). <h3>Results</h3> In the girls, the adolescent spurt in mandibular growth occurred between the ages of 10 and 12 years. In the boys, the adolescent mandibular growth spurt was between 12 and 15 years. Statistically significant growth changes in the average increments of growth of these linear measurements occurred in both sexes between 12 and 15 years. Adolescent peaks in midfacial growth were at prepubertal ages in both sexes. During childhood (5-7 years), much craniofacial growth occurred. Moreover, there was considerable mandibular growth relative to the maxilla in Class III subjects after the adolescent growth spurt. <h3>Conclusions</h3> White Class III subjects showed definite worsening of the relative mandibular prognathism and sagittal skeletal discrepancy between the jaws with growth. The growth pattern of 3 fundamental cephalometric measurements (lower anterior face height, midfacial length, and mandibular length) exhibited differences between Class III male and female subjects in both the timing and the size of average growth increments in the adolescent growth spurt.

Editor's Summary, Q & A, Reviewer's Critique: Dentofacial features of Class II malocclusion associated with maxillary skeletal protrusion: A longitudinal study at the circumpubertal growth period

Introduction The purpose of this study was to describe the craniofacial growth changes of subjects with Class II malocclusion associated with maxillary skeletal protrusion at the circumpubertal growth period. Methods The records of 25 untreated subjects with normal Class I occlusion and 25 untreated Class II subjects (14 boys and 11 girls in each group) were selected from the longitudinal records of the University of Michigan Growth Study. All Class II subjects had maxillary protrusion. Measurements were made on lateral and posteroanterior cephalograms and on dental casts at 2 times. The first observation (T1) was during the prepubertal growth phase (vertebral stages CS1 to CS3). The second observation (T2) was during the postpubertal phase of growth (vertebral stages CS4 to CS6). The following comparisons were made: Class I vs Class II at T1, Class I vs Class II at T2, and growth changes in Class I vs Class II. Results No dentofacial feature studied showed any statistically significant difference when comparing the growth changes between the Class II and the Class I groups. Conclusions These results suggest that dentofacial features of Class II malocclusion associated with maxillary skeletal protrusion are maintained during the circumpubertal period, and that growth changes in this type of Class II disharmony are similar to those in subjects with normal occlusion.

Dentofacial features of Class II malocclusion associated with maxillary skeletal protrusion: A longitudinal study at the circumpubertal growth period

The purpose of this study was to describe the craniofacial growth changes of subjects with Class II malocclusion associated with maxillary skeletal protrusion at the circumpubertal growth period. The records of 25 untreated subjects with normal Class I occlusion and 25 untreated Class II subjects (14 boys and 11 girls in each group) were selected from the longitudinal records of the University of Michigan Growth Study. All Class II subjects had maxillary protrusion. Measurements were made on lateral and posteroanterior cephalograms and on dental casts at 2 times. The first observation (T1) was during the prepubertal growth phase (vertebral stages CS1 to CS3). The second observation (T2) was during the postpubertal phase of growth (vertebral stages CS4 to CS6). The following comparisons were made: Class I vs Class II at T1, Class I vs Class II at T2, and growth changes in Class I vs Class II. No dentofacial feature studied showed any statistically significant difference when comparing the growth changes between the Class II and the Class I groups. These results suggest that dentofacial features of Class II malocclusion associated with maxillary skeletal protrusion are maintained during the circumpubertal period, and that growth changes in this type of Class II disharmony are similar to those in subjects with normal occlusion.