Orthodontic and surgical treatment of facial asymmetry in a patient with unicoronal craniosynostosis.

This case report presents the unique treatment of a patient with varying asymmetries at different levels within the face. The patient was a 17-year-old male with a diagnosis of right unilateral coronal synostosis. He had frontal and superior orbital retrusion on the fused side, and bossing of the contralateral side. The middle and lower portions of his face were rotated toward the nonfused side. This unique diagnosis presented particular challenges to surgical and orthodontic correction. The treatment approach, which included a combination of Le Fort I and II osteotomies, bilateral sagittal split osteotomy, and orthodontic treatment with 4 premolar extractions, enabled simultaneous correction of nasal, midfacial, lower facial, and dental asymmetries. The orthodontist and surgeon integrated their efforts to correct dentofacial asymmetry in all 3 planes of space. Facial esthetics and dental function were significantly improved with no appreciable relapse occurring over a 2-year retention period.

Age-Related Differences in Psychosocial Function of Children with Craniofacial Anomalies.

BACKGROUND: Age is a frequent consideration for surgical timing in pediatric craniofacial surgery for optimal psychosocial development. However, systematic evaluations of the effects of age in children under active treatment have not been thoroughly evaluated. METHODS: Ninety-nine patients (age, 8 to 17 years; 46.5 percent male) from the University of California, Los Angeles, Craniofacial Clinic were prospectively evaluated using the Pediatric Patient-Reported Outcomes Measurement Information System to assess anger, anxiety, depression, and quality of peer relationships. Patients were stratified into three age groups by years: group A, 8 to 10 years, n = 30; group B, 11 to 13 years, n = 41; and group C, 14 to 17 years, n = 28. Analyses of variance and logistic regression analyses were performed. RESULTS: Significant differences in anxiety (F2,96 = 5.1; p = 0.008), depression (F2,96 = 9.7; p < 0.001), peer relationships (F2,96 = 3.5; p = 0.03), and anger (F2,96 = 4.9; p = 0.009) were found among the age groups. Group A demonstrated the highest anxiety, highest depression, and lowest peer relationship scores overall. Although there were no differences in anger between groups A and C, group B had the lowest anger scores. Children with poor scores of higher severity, defined as greater than 1 SD worse than the national mean, were compared. Group A contributed the highest percentages of more severely affected children in all categories. A logistic regression analysis demonstrated that group A was a statistically significant predictor for scores of higher severity in both anxiety (OR, 3.8; 95 percent CI, 1.3 to 11.5; p = 0.02) and peer relationships (OR, 3.4; 95 percent CI, 1.3 to 9.3; p = 0.02). CONCLUSIONS: Children between 8 and 10 years of age with craniofacial anomalies constitute a high-risk subset for psychosocial dysfunction. The authors' work suggests that tight surveillance with family and school awareness may be necessary for this age group. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

Multidisciplinary Treatment of Antley-Bixler Syndrome.

Antley-Bixler syndrome is a rare form of craniosynostosis characterized by unique clinical features that present particular challenges to long-term treatment. Typical craniofacial features include midface hypoplasia, trapezoidocephaly, frontal bossing, ocular proptosis, low-set protrusive ears, and choanal atresia. A staged surgical approach including fronto-orbital and midface advancements is required for intracranial pressure reduction, globe protection, airway patency, and malocclusion. In this case report, the combined, longitudinal surgical and orthodontic treatment strategies employed to correct severe facial deformity in a long-term 21-year survivor of Antley-Bixler syndrome are reviewed.

Congenital and acquired mandibular asymmetry: Mapping growth and remodeling in 3 dimensions.

INTRODUCTION: Disordered craniofacial development frequently results in definitive facial asymmetries that can significantly impact a person's social and functional well-being. The mandible plays a prominent role in defining facial symmetry and, as an active region of growth, commonly acquires asymmetric features. Additionally, syndromic mandibular asymmetry characterizes craniofacial microsomia (CFM), the second most prevalent congenital craniofacial anomaly (1:3000 to 1:5000 live births) after cleft lip and palate. We hypothesized that asymmetric rates of mandibular growth occur in the context of syndromic and acquired facial asymmetries. METHODS: To test this hypothesis, a spherical harmonic-based shape correspondence algorithm was applied to quantify and characterize asymmetries in mandibular growth and remodeling in 3 groups during adolescence. Longitudinal time points were automatically registered, and regions of the condyle and posterior ramus were selected for growth quantification. The first group (n = 9) had a diagnosis of CFM, limited to Pruzansky-Kaban type I or IIA mandibular deformities. The second group (n = 10) consisted of subjects with asymmetric, nonsyndromic dentofacial asymmetry requiring surgical intervention. A control group (n = 10) of symmetric patients was selected for comparison. A linear mixed model was used for the statistical comparison of growth asymmetry between the groups. RESULTS: Initial mandibular shape and symmetry displayed distinct signatures in the 3 groups (P <0.001), with the greatest asymmetries in the condyle and ramus. Similarly, mandibular growth had unique patterns in the groups. The dentofacial asymmetry group was characterized by significant asymmetry in condylar and posterior ramal remodeling with growth (P <0.001). The CFM group was characterized by asymmetric growth of the posterior ramus (P <0.001) but relatively symmetric growth of the condyles (P = 0.47). CONCLUSIONS: Forms of CFM are characterized by active and variable growth of the dysplastic side, which has a distinct pattern from other disorders of mandibular growth.

Three-dimensional soft-tissue and hard-tissue changes in the treatment of bimaxillary protrusion.

INTRODUCTION: Facial convexity related to bimaxillary protrusion is prevalent in many populations. Underlying skeletal protrusion combined with increased dentoalveolar protrusion contributes to facial muscle imbalance and lip incompetence, which is undesirable for many patients. In this study, we evaluated the relationship between soft-tissue and hard-tissue changes in an orthodontically treated Asian population. METHODS: Twenty-four consecutive adult Asian patients (mean age, 24 years), diagnosed with severe bimaxillary dentoalveolar protrusion, were evaluated using pretreatment and posttreatment cone-beam computed tomography. The patients were treated with 4 first premolar extractions followed by anterior retraction with either skeletal or intraoral anchorage. Serial cone-beam computed tomography radiographs were registered on the entire cranial base and fossa. Soft-tissue and hard-tissue changes were determined through landmark displacement and color mapping. RESULTS: Upper lip retraction was concentrated between the nasolabial folds and commissures. Lower lip retraction was accompanied by significant redistribution of soft tissues at pogonion. Soft-tissue changes correlated well with regional facial muscle activity. Significant retractions (2-4 mm) of the soft tissues occurred beyond the midsagittal region. Use of skeletal anchorage resulted in 1.5 mm greater lower lip retraction than intraoral anchorage, with greater retraction of the maxillary and mandibular incisor root apices. CONCLUSIONS: Profound soft-tissue changes accompanied retraction of the anterior dentition with both treatment modalities.

Mesenchymal and mechanical mechanisms of secondary cartilage induction.

Secondary cartilage occurs at articulations, sutures, and muscle attachments, and facilitates proper kinetic movement of the skeleton. Secondary cartilage requires mechanical stimulation for its induction and maintenance, and accordingly, its evolutionary presence or absence reflects species-specific variation in functional anatomy. Avians illustrate this point well. In conjunction with their distinct adult mode of feeding via levered straining, duck develop a pronounced secondary cartilage at the insertion (i.e., enthesis) of the mandibular adductor muscles on the lower jaw skeleton. An equivalent cartilage is absent in quail, which peck at their food. We hypothesized that species-specific pattern and a concomitant dissimilarity in the local mechanical environment promote secondary chondrogenesis in the mandibular adductor enthesis of duck versus quail. To test our hypothesis we employed two experimental approaches. First, we transplanted neural crest mesenchyme (NCM) from quail into duck, which produced chimeric "quck" with a jaw complex resembling that of quail, including an absence of enthesis secondary cartilage. Second, we modified the mechanical environment in embryonic duck by paralyzing skeletal muscles, and by blocking the ability of NCM to support mechanotransduction through stretch-activated ion channels. Paralysis inhibited secondary cartilage, as evidenced by changes in histology and expression of genes that affect chondrogenesis, including members of the FGF and BMP pathways. Ion channel inhibition did not alter enthesis secondary cartilage but caused bone to form in place of secondary cartilage at articulations. Thus, our study reveals that enthesis secondary cartilage forms through mechanisms that are distinct from those regulating other secondary cartilage. We conclude that by directing the musculoskeletal patterning and integration of the jaw complex, NCM modulates the mechanical forces and molecular signals necessary to control secondary cartilage formation during development and evolution.