Feasibility of spheno-occipital synchondrosis fusion stages as an indicator for the assessment of maxillomandibular growth: A mixed longitudinal study.

OBJECTIVES: This study aimed to assess the relative growth rates (RGRs) of the maxilla and mandible at varying fusion stages of the spheno-occipital synchondrosis (SOS), thereby elucidating the potential of SOS stages in predicting maxillomandibular growth. MATERIALS AND METHODS: A total of 320 subjects (171 boys and 149 girls), aged 6 to 18 years, were retrospectively included. Each subject had a minimum of two longitudinal cone-beam computed tomography (CBCT) images, with no more than one interval of SOS fusion stage change between the two scans. Subjects were categorized based on their SOS fusion stages and genders. The RGRs of the maxilla and mandible at various SOS fusion stages were measured and compared using longitudinal CBCT images. RESULTS: Significant statistical differences were observed in maxillomandibular RGRs across various SOS fusion stages. In girls, the sagittal growth of the maxilla remained stable and active until SOS 3, subsequently exhibited deceleration in SOS 4-5 (compared to SOS 3-4, P < .05) and continued to decrease in SOS 5-6. Whereas in boys, the sagittal growth of the maxilla remained stable until SOS 4, and a deceleration trend emerged starting from SOS 5 to 6 (P < .01 compared to SOS 4-5). Mandibular growth patterns in both genders exhibited a progression of increasing-accelerating-decelerating rates from SOS 2 to 6. The highest RGRs for total mandibular length were observed in SOS 3-4 and SOS 4-5. CONCLUSION: Spheno-occipital synchondrosis fusion stages can serve as a valid indicator of maxillomandibular growth maturation.

Three-dimensional computed tomographic assessment of mandibular muscles in growing subjects with different vertical facial patterns.

AIM: The present study was undertaken to assess the relationship between the mandibular muscles and dentofacial skeletal morphology in children with different underlying vertical facial patterns, using three-dimensional computed tomography (3D-CT). METHOD: Thirty children (mean age 12.24 ± 1.57 years) underwent cranial CT examination for diagnostic purposes. 3D-CT images were reconstructed for the evaluation of the cross-sectional size, volume, and spatial orientation of the masseter and medial pterygoid muscles. These muscle parameters were also assessed in relation to the vertical facial pattern, gender and skeleto-dental form. RESULTS: Significant differences were found in muscular angulation for subjects with different underlying patterns. Greater masseter volumes were associated with increased facial width. Greater intermolar widths were found in brachyfacial subjects, with less acute muscular angulations in relation to horizontal reference lines, compared with dolichofacial subjects. This was also more obvious in the maxillary arch. CONCLUSION: Clinicians should note the likely differences in masseter and medial pterygoid orientation and volume in subjects with different underlying vertical facial patterns and that these differences may, in turn, be related to both facial skeletal width and naturally-occurring transverse dental arch dimensions.

Assessment of Labionasal Structures in Patients With Unilateral Cleft Lip.

INTRODUCTION: Unilateral cleft lip (UCL) patients have lip and nose deformities that must be addressed during lip repair. Currently, devices to achieve lip and nose improvements have been developed. The most researched presurgical molding device is the nasoalveolar molding (NAM), which has shown favorable results. However, clinical observation shows that unilateral cleft patients, even without molding devices, achieve spontaneous improvements. The aim of this study is to compare morphological and symmetry changes in nose and lip, between patients less than 30-day old and those submitted to cheiloplasty, at 6 months of age. MATERIALS AND METHODS: A total of 27 UCL patients with 2 photographs were selected. The pictures were taken from frontal view and nasal base view at 2 distinct moments: before 30 days of life (t1) and at 6 months of age, during cheiloplasty surgery (T2). Images were analyzed with indirect measurement to assess lip and nose dimensions and nasal symmetry. ImageJ software was used to perform the analyses. RESULTS: A total of 20 patients (P < 0.05) had an average cleft width reduction of 15% [standard deviation (SD) ± 11%]. A 55% average increase (SD ± 29%) was observed in nostril height of cleft side in 16 of patients (P < 0.05). There was an reduction in facial asymmetry of nostril width (P < 0.05), from 95% (SD ± 90%) (t1) to 59% (SD ± 50) (T2). Also, nasal base width asymmetry (P < 0.05) was decreased from 64% (SD ± 66%) (t1) to 40% (SD ± 29%) (T2). CONCLUSION: Facial growth causes a natural improvement on cleft morphological changes and nasal symmetry.

American Association of Orthodontists Foundation Craniofacial Growth Legacy Collection: Overview of a powerful tool for orthodontic research and teaching.

This article reports on the current status of the American Association of Orthodontists Foundation (AAOF) Craniofacial Growth Legacy Collection--an AAOF-supported multi-institutional project that uses the Internet and cloud computing to collect and share craniofacial images and data for orthodontic research and education. The project gives investigators and clinicians all over the world online access to longitudinal information on craniofacial development in untreated children with malocclusions of various types. It also is a unique source of control samples for testing the validity of consensually accepted beliefs about the effects of orthodontic treatment or of failure to treat.

Assessment of the soft tissue thickness at the lower anterior face in adult patients with different skeletal vertical patterns using cone-beam computed tomography.

OBJECTIVE: To evaluate and compare the soft tissue thickness values at the lower anterior face among adult patients with different vertical growth patterns using cone-beam computed tomography. MATERIAL AND METHODS: The study sample consisted of 105 adult patients (54 women and 51 men) with a normal sagittal skeletal pattern divided into three groups according to the vertical growth pattern: high-angle (women/men, 22/13; mean age, 24.54 ± 4.45 years), low-angle (women/men, 14/21; mean age, 24.62 ± 5.08 years), and normal-angle (women/men, 18/17; mean age, 24.22 ± 5.40 years) groups. The soft tissue thickness measurements at the lower anterior face in each group were done and analyzed using the one-way analysis of variance and Tukey tests. RESULTS: Soft tissue thickness values were the lowest in the high-angle group for both women and men. For women, the thickness values at the labrale superius, labrale inferius, and pogonion were found to be statistically significantly smaller in the high-angle group (11.49 ± 1.05 mm, 12.70 ± 1.92 mm, and 11.64 ± 2.65 mm, respectively) compared with the values in the normal-angle group (13.31 ± 2.01 mm, 15.08 ± 1.94 mm, and 14.69 ± 3.08 mm, respectively) (P < .05, P < .05, and P < .01, respectively). For men, however, no statistically significant differences were found among the vertical growth patterns (P > .05). CONCLUSION: Women had statistically significantly thinner thickness at the labrale superius, labrale inferius, and pogonion in the high-angle group compared with the normal-angle group.

Three-dimensional assessment of facial asymmetry among pre-pubertal class III subjects: a controlled study.

BACKGROUND/OBJECTIVE: Facial asymmetry is very common in adult class III patients; however, the degree of facial asymmetry in growing class III subjects has been poorly investigated. Therefore, the aim was to assess the degree of facial asymmetry of growing class III subjects and to compare it with a sample of growing subjects without malocclusion, recorded using a three-dimensional laser scanning method and classified according to the dentition phase. SUBJECTS/METHODS: A group of 156 Caucasian subjects, 52 with class III malocclusion (28 females and 24 males) and 104 without malocclusion (control, 51 females and 53 males), with an overall mean age 6.7±1.4 years (range 4.3-10.3 years), were included. The subjects were further subdivided according to the presence of either primary or early/intermediate mixed dentitions. Facial asymmetry was assessed on three-dimensional surface facial images obtained using a laser scanning device in terms of mirrored face distances and percentages of asymmetry. Multivariate analyses were used to assess the differences among class III and control groups. RESULTS: Complete facial symmetry was not seen in any subject. No significant differences of facial asymmetry were observed between the class III and control groups, neither in the primary nor in the early/intermediate mixed dentition phases. LIMITATIONS: No conclusions about longitudinal changes in the degree of facial asymmetry among class III subjects could be drawn from the present cross-sectional study. CONCLUSIONS: Based on three-dimensional facial asymmetry analysis, class III subjects do not show clinically relevant facial asymmetry, at least during the pre-pubertal growth period.

Cephalometric assessment of human fetal head specimens.

BACKGROUND: Past investigations of prenatal craniofacial growth have largely relied on histological sections. Few studies have taken measurements on three-dimensional representations (3D reconstruction, 3D CT, postmortem) or varying depth levels (ultrasound), and we know of no craniofacial growth studies done on cleared-and-stained specimens of whole fetal heads. MATERIALS AND METHODS: This study comprised 14 human fetal head specimens cleared and stained with alizarin red and alcian blue. They had been stored in glycerol and represented weeks 8-12 of gestation, with crown-rump lengths ranging from 23-145 mm. These specimens were cephalometrically analyzed in norma frontalis and norma lateralis, which notably included the opportunity for side-to-side comparison. RESULTS: As the cranial membrane bones progressively approached each other, the orbits, maxilla, and mandible gradually grew wider. Likewise, the sagittal dimensions of the maxilla and mandible increased continuously and synchronically. We noted side-to-side differences ranging from 2-5 mm. Another notable finding concerned the inclination of the maxilla relative to the cranial base, which increased more on the right than on the left side. CONCLUSION: This is the first investigation presenting side-to-side comparative measurements of human fetal head specimens. Such measurements are essential in the quest toward validating the findings of other imaging techniques such as CT or MRI and-most importantly-intrauterine sonography.

Presurgical infant orthopedics.

This article focuses on current practices and controversy in the area of presurgical infant orthopedics in patients born with cleft lip and palate.

Clinical decision making regarding endodontics versus implants.

This article discusses the current considerations in treatment planning for retention of the natural tooth through endodontic therapy (including orthograde first-time treatment, retreatment, and endodontic surgery) versus extraction and placement of a dental implant. As a secondary goal, the article describes several specific cases in which the best option is either an implant or retention of the natural tooth. The issue of tooth retention versus implant therapy is also addressed with regard to the specific clinical diagnosis of resorption in all of its various forms. Emphasis has been placed on practical strategies for treatment of cases involving internal and external root resorption using a comprehensive evidence-based approach.

Relationship between blood-spot insulin-like growth factor 1 levels and hand-wrist assessment of skeletal maturity.

INTRODUCTION: Accurate prediction of the timing of the pubertal growth spurt and the amount of remaining growth are factors that affect treatment decisions in orthodontics, orthognathic surgery, and dental implantology. For many years, medical and dental professionals have considered hand-wrist radiographs the method of choice for the assessment of skeletal maturity. Insulin-like growth factor 1 (IGF-1) mirrors growth hormone levels and is used by endocrinologists to diagnose growth hormone disturbances. METHODS: The objective of this study was to establish a relationship between IGF-1 levels collected from blood-spot samples and hand-wrist radiographs at various skeletal stages. Eighty-four subjects (45 female, 39 male) between the ages of 5 and 25 were included in the study. Each subject had personal information, a hand-wrist radiograph, and a blood-spot sample collected on the same day. RESULTS: The IGF-1 levels were highest at the hand-wrist skeletal stages that were previously associated with the greatest amount of mandibular growth. These levels were significantly higher than at prepubertal and postpubertal stages. In the postpubertal group, the IGF-1 levels were lower as the subjects' ages increased and they moved away from the onset of puberty. CONCLUSIONS: Longitudinal data are necessary to confirm the usefulness of this technique in predicting the timing, the intensity, and the end of the growth spurt.

Cephalometric superimposition on the occipital condyles as a longitudinal growth assessment reference: I-point and I-curve.

This retrospective study tests the hypothesis that superimposition referenced at the occipital condyles (defined as I-point, I-curve) and oriented to the anterior cranial base (ACB) will display a growth pattern that is more consistent with independent evaluations, such as the Melsen necropsy specimens and the Bjork implant studies, when compared with traditional superimpositions referenced at sella turcica. Twenty-eight sets of serial lateral cephalometric radiographs were selected from an archived growth study. The apparent facial growth was compared using polar coordinate analysis from superimposition tracings of the serial films for each subject. The two superimposition methods were compared. The traditional method, ACB registered on the anterior curvature of sella turcica, versus registration on I-point while maintaining ACB parallel. I-point registered superimpositions consistently displayed a facial growth pattern that was more consistent with the classic necropsy specimens of children and the cephalometric studies superimposing on implant markers. Traditional ACB superimposition suggests that airway is restricted by normal growth. This apparent physiologic artifact does not occur when superimpositions are registered on I-point. Sella turcica displays vertical movement that is consistent with brain growth. These data indicate that registration on I-point is a more accurate physiologic representation of facial growth than the traditional ACB superimpositions. When compared with the traditional registration at sella turcica, I-point superimposition better elucidates physiologic growth patterns. As cephalometrics evolve from a two to a three dimensional science, it is important to use a more biologically valid registration for evaluating therapeutics and facial growth patterns.

Geometric morphometric assessment of treatment effects of maxillary protraction combined with chin cup appliance on the maxillofacial complex.

The aim of this study was to investigate the treatment effects on the maxillofacial complex by maxillary protraction combined with chin cup therapy among growing children. An effective geometric morphometric assessment of cephalometric radiographs, using Procrustes analysis and thin-plate spline analysis, was applied to evaluate shape change in the craniofacial and midfacial configurations of a treated sample of 20 children with skeletal Class III malocclusion. This was compared with matched untreated skeletal Class III controls. Marked treatment induced change involved the maxilla and the mandible. Major deformation consisted of forward advancement of the maxillary complex with negligible rotation of the palatal plane and a forward direction of growth of the mandibular condyle associated with a restriction in sagittal advancement of the chin. Considerable dentoalveolar components contributed to the correction of anterior crossbite. Further detailed study of skeletofacial remodelling in response to maxillary protraction in other skeletal components, including the cranial base and the mandibular complex that contribute to Class III skeletal discrepancies, is warranted.

Treatment outcomes of growing Class II Division 1 patients with varying degrees of anteroposterior and vertical dysplasias, Part 1. Cephalometrics.

The purpose of this retrospective study was to evaluate the differences in orthodontic treatment outcomes for 5 groups of growing Class II Division 1 patients with various anteroposterior and vertical skeletal dysplasias. Pretreatment and posttreatment cephalograms of 100 patients were evaluated for soft and hard tissue treatment effects and differences between groups. Changes from pretreatment to posttreatment differed between groups in correction of overjet and change in ANB angle (P <.05). Those with the largest skeletal dysplasias had the greatest skeletal correction but also retained the largest ANB angles posttreatment. Additional correction was achieved through dentoalveolar change with the greatest uprighting of maxillary incisors occurring in patients who initially were the most severely affected (P <.05); this effect was accompanied by an increase in nasolabial angle. All groups had similar changes in mandibular incisor positions, and final positions of the mandibular incisors did not differ between groups. Compared with norms, Z angles and facial contour angles showed discrimination between the most and least severely affected patients based on combined anteroposterior and vertical dysplasias (P <.05). However, there were no clear-cut divisions between the groups, especially with regard to soft tissue cephalometric outcomes. Further evaluation of profile esthetics follows in Part 2. We conclude that conventional orthodontic therapy successfully corrects Class II Division 1 malocclusions in growing patients through a combination of skeletal and dentoalveolar changes, with the greatest changes occurring in patients who initially have the most severe skeletal dysplasias.