Microtia: epidemiology and genetics

Integrated biomimetic bioprinting of perichondrium with cartilage for auricle reconstruction

The construction and regeneration of tissue-engineered auricles are pacesetters in tissue engineering and have realized their first international clinical application. However, the unstable regeneration quality and insufficient mechanical strength have become significant obstacles impeding its clinical promotion. The perichondrium is indispensable for the nutritional and vascular supply of the underlying cartilage tissue, as well as for proper anatomical functioning and mechanical performance. This study presents a novel strategy for integrated construction of bioengineered perichondrium with bioprinted cartilage to enhance the regeneration quality and mechanical properties of tissue-engineered auricles. Simulating the anatomical structure of the native auricle designs a sandwich construction model containing bilateral perichondrium and intermediate cartilage, employing a photocrosslinkable acellular cartilage matrix and gelatin bionics matrix microenvironment, applying co-cultured auricular chondrocytes and adipose-derived stem cells creates functional cell populations, designing hatch patterns imitates microscopic arrangement structures, utilizing sacrificial materials forms interlaminar network traffic to enhance the tight connection between layers, and finally, assessing the regenerative quality of the constructs explores their feasibility and stability. The multi-level and multi-scale biomimetic construction strategy overcomes the technical limitation of the integrated construction of perichondrium-wrapped auricles and realizes biomimicry in morphology, structure, and biomechanics. Altogether, this study provides a technical reference for the hierarchical construction of complex tissues and promotes the clinical translation and application of engineered tissues or organs.

Audiological assessment using click auditory brainstem response and chirp auditory steady-state response in pediatric patients with congenital microtia under 36 months: A single-center experience

OBJECTIVE

To investigate the audiological characteristics of congenital microtia (CM), and explores the effectiveness of click auditory brainstem responses (c-ABR) and chirp auditory steady-state responses (chirp-ASSR) in assessing hearing loss in affected children.

METHODS

Audiological assessments were performed using c-ABR and chirp-ASSR in infants and toddlers under 36 months with CM who were unable to cooperate for behavioral testing. We used c-ABR to assess the nature of hearing loss. Spearman coefficients were used to evaluate correlations, and differences were assessed by subtracting c-ABR air conduction (AC) thresholds from chirp-ASSR AC thresholds. Additionally, differences were analyzed based on the external auditory canal status, auricle status, unilateral or bilateral CM.

RESULTS

The findings indicate that most CM patients experience conductive hearing loss (CHL, 90.36 %) and mixed hearing loss (MHL, 8.21 %), with a smaller number exhibiting normal (0.71 %) or sensorineural hearing loss (SNHL, 0.71 %). Across the entire sample, ABR thresholds showed the strongest correlation with ASSR thresholds at an average of 2-4 kHz (r = 0.723). Chirp-ASSR was found to be a complementary test to c-ABR for screening hearing loss in CM patients, particularly when behavioral testing is not feasible. Significant differences were found in patients with external auditory canal atresia and stenosis, as well as in those with different auricle statuses (Grade I + II, and Grade III).

CONCLUSION

The study supports the use of c-ABR and chirp-ASSR as valuable tools in the audiological assessment of congenital microtia, aiding in early diagnosis and appropriate intervention for hearing loss in pediatric patients.

An experimental investigation into the correlation between the diameter of reimplanted cartilage blocks and efficacy of cartilage regeneration after auricular reconstruction

Preventing thoracic deformities during auricular reconstruction is a challenge for surgeons who utilize multiple costal cartilage grafts to fabricate a 3-dimensional framework. Reimplantation of cartilage blocks reduces thoracic deformities, but there is no consensus on how to maximize the effectiveness of reimplantation. We aimed to investigate the correlation between the block diameter and the efficacy of cartilage regeneration at the donor site in a rabbit model. Seventy-two rabbits were randomly placed into 6 groups: those with reimplanted cartilage blocks with a diameter of (1) 0.7 mm, (2) 0.6 mm, (3) 0.5 mm, (4) 0.4 mm, (5) 0.3 mm, and (6) the control group. Cartilage blocks of various diameters were shredded and returned to the perichondrial pocket at the donor site. The efficacy of promoting biomechanical strength, cartilage tissue growth, activation of chondrocyte proliferation, and stimulation of cartilage-specific extracellular matrix secretion was assessed. The diameter of the implanted cartilage block was a highly correlated factor during regeneration. Smaller diameters with appropriate interstitial spaces between blocks promoted better cartilage tissue growth, chondrocyte proliferation, and extracellular matrix secretion. According to our findings, 0.4 mm is the maximum diameter for achieving the best regeneration performance (range, 0.3-0.7 mm).

Genetic characteristics associated with isolated Microtia revealed through whole exome sequencing of 201 pedigrees

Microtia is one of the most common congenital craniofacial malformations, characterized by the maldevelopment of the external and middle ear. While numerous genes have been implicated in syndromic forms of microtia, the genetic underpinnings of isolated microtia remain poorly understood. In this study, we conducted whole exome sequencing (WES) on 201 pedigrees with isolated microtia to investigate its genetic basis. Bioinformatics analysis identified 1362 deleterious variants corresponding to 332 candidate genes, including 40 previously associated with microtia-related phenotypes. Among these, variants in FOXI3, the most frequently identified pathogenic gene for isolated microtia so far, were detected. Remarkably, the remaining 39 genes, which have been recognized as pathogenic in syndromes with microtia, are also suggested to play a role in isolated microtia. However, the precise molecular mechanisms by which these genes contribute to microtia remain to be elucidated. Furthermore, through protein-protein interaction network analysis, functional annotation, and zebrafish expression profiling, we identified two novel genes, MCM2 and BDNF, as the most promising contributors to the pathogenesis of isolated microtia. Our findings, based on the largest WES study of isolated microtia pedigrees to date, provide new insights into the genetic architecture of isolated microtia and suggest promising avenues for future research.

Adipose-mesenchymal stem cells enhance the formation of auricular cartilage in vitro and in vivo

Patients suffering from microtia have limited treatment options for auricular reconstruction due to donor-site morbidity, complications, and unaesthetic outcome. Therefore, tissue engineering emerged as an alternative therapeutic option. Here, we generated and characterized human auricular cartilage using differentiated human adipose mesenchymal stem cells (hASCs) combined with human auricular chondrocytes. The differentiated hASCs were analysed for their morphology, phenotype, gene, and protein expression of chondrogenic markers, and biochemical composition at different time points in 2D and 3D in vitro. Importantly, we improved conditions for chondrogenic differentiation of hASCs in vitro to enhance their proliferation, survival, and deposition of cartilaginous-matrix proteins. In particular, gene expression analysis revealed an upregulation of cartilage oligomeric matrix protein (COMP) and aggrecan core protein (ACAN) in hASCs using the improved differentiation protocol in vitro. Additionally, we observed that co-seeding of hASCs with chondrocytes in a 1:5 ratio significantly enhanced the de novo auricular cartilage formation in a collagen-I bioink after 8 weeks on immunodeficient rat. In particular, the co-culture resulted in reduced shrinkage, and increased cartilage matrix production as confirmed by GAG deposition in vivo. Our results demonstrate that in co-cultures, hASCs stimulate cartilage formation due to a synergistic effect: hASCs' differentiation into chondrocytes and a trophic effect of hASCs on human auricular chondrocytes. Here we demonstrate the successful use of an hASC-chondrocyte co-culture technique for auricular cartilage tissue engineering in 3D collagen-I bioink. This co-culture approach omits the major drawbacks of traditional cartilage transplantation and thus, represents a fundamental step towards clinical translation.

Pathogenic variants in SHROOM3 associated with hemifacial microsomia

Hemifacial microsomia (HFM) is a rare congenital disorder that affects facial symmetry, ear development, and other congenital anomalies. However, known causal genes account for only approximately 6% of patients, indicating the need to discover more pathogenic genes. Association tests demonstrated an association between common variants in SHROOM3 and HFM (P = 1.02E-4 for the lead SNP), while gene burden analysis revealed a significant enrichment of rare variants in HFM patients compared to healthy controls (P = 2.78E-5). We then evaluated the expression patterns of SHROOM3 and the consequences of its deleterious variants. Our study identified 7 deleterious variants in SHROOM3 among the 320 Chinese HFM patients and 2 deleterious variants in two HFM trios, respectively, suggesting a model of dominant inheritance with incomplete penetrance. These variants were predicted to significantly impact SHROOM3 function. Furthermore, the gene expression pattern of SHROOM3 in the pharyngeal arches and the presence of facial abnormalities in gene-edited mice suggest that SHROOM3 plays important roles in facial development. Our findings suggest that SHROOM3 is a likely pathogenic gene for HFM.

Socioeconomic disparities in reconstructive pediatric microtia surgery

OBJECTIVE

To assess the association of race/ethnicity and education status on time to intervention and the total number of interventions in pediatric patients with microtia undergoing hearing intervention and external ear reconstruction.

METHODS

A retrospective chart review was performed in pediatric patients diagnosed with congenital ear deformities evaluated by an otolaryngologist or audiologist from January 1, 2013 to December 1, 2021 at a large surgical institution. Variables analyzed included demographics, patient conditions, time to surgery, and number of surgeries. Statistical analysis included analysis of variance, chi-squared tests, and multivariate regression.

RESULTS

Disparities were identified in reconstructive microtia repair, with non-White patients having an increased number of external ear reconstructive surgeries (p = 0.004), with Black patients average 2 external ear reconstructive surgeries, Hispanic patients 1.74 surgeries, while White patients averaged 0.812 surgeries. All non-White patients also demonstrated increased total number of surgeries (1.94 Asian, 2.57 Black, 2.11 Hispanic, 3.29 Other/Unknown, vs 1.23 White, p = 0.007) and total number of interventions (2.17 Asian, 2.71 Black, 2.37 Hispanic 3.43 Other/Unknown, vs 1.56 White, p = 0.02) as compared to White patients. In multivariate regression analysis, race was a significant factor influencing the number of reconstructive and overall surgeries, while the presence of aural atresia was the strongest predictor for requiring additional hearing surgery.

CONCLUSION

An increased number of interventions and surgeries were seen amongst non-White patients with microtia. Further investigation is warranted to understand the socioeconomic factors associated with pediatric microtia surgery.

Reconstructive Techniques in Pediatric Congenital Microtia: A Systematic Review and Meta-analysis

Autografts and allografts are commonly used in microtia reconstruction. We aimed to systematically review and compare these reconstructive materials in pediatric congenital microtia reconstruction. A systematic review of the literature was performed. MEDLINE, Embase, PubMed, Web of Science, and CINAHL databases were searched for original studies on congenital microtia reconstruction in pediatric patients since database inception to 2021. Microtia grade was stratified as high or low. Meta-analysis of pooled proportions and continuous variables was performed using inverse variance weighting with a random effects model to compare between the autograft and allograft groups. Sixty-eight studies with a total of 5,546 patients used autografts (n = 5,382) or alloplastic implants (n = 164). Four other studies used prosthesis, cadaveric homografts, or tissue engineering. The allograft group was on average younger than the autograft group (8.4 vs. 11.1 years). There were no syndromic patients in the allograft group, compared to 43% in the autograft group. Patients treated with allografts had higher microtia grade than those treated with autograft (98 vs. 72%). Autografts were more commonly utilized by plastic surgeons and allografts by otolaryngologists (95 vs. 38%). No autografts and 41% of allografts were done concurrently with atresiaplasty or bone conduction implant. Satisfaction rates were similarly high (>90%) with similar complication rates (<10%). Microtia reconstruction using autografts and allografts had similar satisfaction and complication rates. Allografts were preferred for younger patients and concurrent hearing restoration. Further large-scale studies are required to evaluate the long-term efficacy of these reconstructive techniques.

Microtia: A Review

Microtia is a congenital condition characterized by a spectrum of ear malformations, ranging from minor structural anomalies to anotia. The etiology is multifactorial, with interplay of genetic and environmental factors being implicated. Early multidisciplinary involvement should include pediatrics, plastic surgery, otolaryngology, audiology, and speech pathology, to ensure that the child is appropriately supported as they grow. This article provides an overview of the condition, a brief historic review, and illustrated descriptions of 2 common surgical approaches: porous polyethylene reconstruction with a temporoparietal fascia flap, and autologous reconstruction in 2 stages following Firmin's modifications of the Nagata technique.

Genetics of Nonsyndromic Microtia and Congenital Aural Atresia: A Scoping Review

OBJECTIVE

To review the literature on genetics of nonsyndromic microtia and congenital aural atresia (CAA).

DATA SOURCES

Embase, Ovid (Medline), and Web of Science.

REVIEW METHODS

The search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for scoping reviews. Included studies were original research studies discussing the genetics or pattern of inheritance of non-syndromic microtia and/or CAA, defined as microtia and/or CAA that was completely isolated except for the presence of hearing loss.

RESULTS

Thirty studies met inclusion criteria, describing 40 unique genes and one susceptibility gene locus (4p15.32-4p16.2) associated with nonsyndromic microtia, CAA, or microtia and CAA. The 3 most cited genes describing microtia genetics alone were HOXA2, MUC6, and GSC. A single article describing nonsyndromic CAA alone identified the TSHZ1 as a candidate gene. Among 194 subjects from 18 manuscripts describing mendelian inheritance for non-syndromic microtia or microtia and CAA, 49% of the individuals were found to have autosomal dominant transmission, 4% had autosomal recessive, 5% had X-linked recessive, and 42% had no reported pattern of inheritance.

CONCLUSION

Current literature on the genetics of microtia and CAA is largely derived from genetic analysis of syndromic patients. Despite comprising over half of the clinical population, available data on non-syndromic patients remains limited. Understanding genetic polymorphisms and their correlation to phenotypic data more readily available to otolaryngologists offers the prospect of categorizing severity of anatomic malformation and hearing loss to guide future intervention, and improve ability to provide patient- and family-centered counseling.

Evaluation of the success rate, prosthesis-related quality of life, and satisfaction in patients undergoing rehabilitation with an implant-supported auricular prosthesis

The aim of this study was to evaluate the success rate, prosthesis-related quality of life (QoL), and satisfaction of patients undergoing rehabilitation with endosseous implants in the auricular region. This was a retrospective mixed cohort study involving 22 consecutive eligible patients (11 female, 11 male) with ear defects, treated during 1999-2019. The variables analysed were sex, age at the time of implant placement, date of last prosthesis delivery, level of education, aetiology of the deformity, and radiation history. The questionnaire results were analysed using IBM SPSS Statistics software. The correlation between QoL and satisfaction was evaluated using the Pearson correlation coefficient. Implant success was calculated clinically using the number of integrated implants, mobility, and presence of a purulent discharge. For the 22 patients, the mean duration since prosthesis placement was 10.2 ± 5.2 years. Among 47 implants inserted, one failed because of osseointegration failure. Hence, the overall success rate of the auricular implants was 97.9%. The mean ± standard deviation total QoL score and satisfaction score were 52.5 ± 7.10 (maximum possible score 80) and 42.1 ± 6.29 (maximum possible score 55), respectively. The results demonstrate the importance of prosthetic rehabilitation for improved patient QoL and satisfaction.

Evaluation of Family-Centered Care by Parents and Nurses of Children With Congenital Microtia

BACKGROUND

The family-centered care is widely applied in pediatric nursing; however, there has been no research reflecting its extent of practice in the auricular reconstruction process for families of children with congenital microtia in China.

OBJECTIVE

This study aims to understand the perspectives of parents of children with congenital microtia and nurses at auricular reconstruction centers in Beijing, China, regarding family-centered care practices and specific areas that need improvement.

METHODS

The study utilized the Measure of Processes of Care (MPOC-20) and the Measure of Processes of Care for Service Providers (MPOC-SP) to survey 100 parents and 22 nurses. Scores for each dimension and item with low score (1-4 points, representing for at least 25% respondents) were statistically analyzed, indicated deficiencies in care services. The scores of parents and nurses were compared with international data.

RESULTS

In this study, the dimension scores of the MPOC-20 ranged from 5.34 ± 1.22 (Coordinated and Comprehensive Care) to 5.57 ± 1.22 (Providing Specific Information). The dimension scores of the MPOC-SP ranged from 5.91 ± 1.08 (Showing Interpersonal Sensitivity) to 6.25 ± 1.20 (Providing General Information). Both sets of scores were higher than most previous studies, particularly in Providing General Information.

CONCLUSION

Parents of children with congenital microtia and nurses generally rated family-centered care practices positively. However, improvements are needed in Coordinated and Comprehensive Care and Showing Interpersonal Sensitivity. Future efforts should aim to enhance the care system for microtia by standardizing care service content, increasing auditory and psychological interventions, and strengthening long-term follow-up care.

Improvement of Quality of Life After Microtia Reconstruction Using a Modified Firmin Technique-Case Series of 130 Patients

BACKGROUND

Microtia usually presents as a unilateral defect often associated with hearing impairment and significant psychosocial challenges. Reconstruction with autologous rib cartilage is currently the gold standard due to lower complication rates. However, outcomes remain variable.

AIMS AND OBJECTIVES

This study aims to assess the outcomes of a modified two-stage surgery technique, focusing on complications, aesthetics, satisfaction, and quality of life.

MATERIALS AND METHODS

A retrospective review of 130 patients undergoing ear reconstruction from 2016 to 2022 was conducted. Data included defect etiology, classification, and complications. Quality of Life was assessed using an adaptation of the questionnaire proposed by UK Care Standards for the Management of Patients with Microtia and Atresia.

RESULTS

Most patients had congenital microtia (78%), with type III being the most common (81%). The majority were male (73%), with a mean age of 21 years. Surgeon-assessed outcomes were good in 90% of cases. The most common complication was partial skin necrosis (13%). Among 73 respondents (answer rate of 56%), there was a significant improvement in quality of life post-reconstruction (p = 2.4e-12).

CONCLUSION

Modifications to Firmin's technique, such as smaller thoracic incisions, limited dissection, and specific flap designs, enhanced aesthetic results while reducing complications. In conclusion, our modified technique offers improved outcomes in microtia reconstruction, emphasizing the importance of technical refinements in achieving satisfactory results and enhancing patient well-being.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors  www.springer.com/00266 .

Microtia in Indonesia: Characteristics and Family History Analysis on the Presence of Other Congenital Anomalies in Patients With Microtia

This study aims to explore the characteristics of microtia in Indonesia and examine whether family traits influence its severity, focusing on other congenital anomalies in patients categorized as either isolated or syndromic microtia.

This study is a descriptive-analytical study with a cross-sectional design.

Questionnaires were distributed via the WhatsApp group "Indonesian Microtia Family," established by the Airlangga University Hospital Microtia Team.

A total of 354 respondents completed the questionnaire, comprising patients with microtia and their family members and relatives.

There is no intervention in this study.

The data on the characteristics of patients with microtia are presented in a descriptive form. An analysis was conducted to determine the influence of family characteristics on the presence of other congenital anomalies in patients.

Familial microtia, defined as microtia occurring in patients with a family history of microtia or related anomalies such as preauricular tags and preauricular fistulas, significantly influences the presence of additional congenital malformations (syndromic microtia), as indicated by a P value of .018. An odds ratio of 3.191 was obtained, indicating that the risk of isolated microtia occurrence is 3 times higher in familial microtia compared to sporadic microtia.

In Indonesia, the majority of patients with microtia are male (78%), unilateral right (55.9%), third-degree Hunter (64.4%), solitary (72%), and sporadic (88.1%). Compared to sporadic microtia, familial microtia will increase the probability of isolated microtia occurrence by 3-fold.

Evaluation of Situs Inversus Combined With Plastic Surgery-Related Malformations in a Chinese Clinic Population

BACKGROUND

Situs inversus is a congenital malformation that occurs in one or multiple organs simultaneously and can be accompanied by malformations in other body parts. We analyzed the prevalence and phenotype of patients with situs inversus and comorbidities associated with other plastic surgery-related malformations to enhance the knowledge of its related disorders and facilitate treatment.

METHODS

We recruited patients with situs inversus who were seen at our institution from February 2015 to July 2023. They underwent ultrasound and physical examinations to investigate deformity in other body parts. Fisher's exact test was used to analyze the laterality between hemifacial microsomia and situs inversus type.

RESULTS

All 14 patients with situs inversus had plastic surgery-related malformations-three congenital and three developmental. Nine (65%) patients had hemifacial microsomia (right side, n = 8; bilateral, n = 1). The laterality of hemifacial microsomia was associated with the situs inversus type, with a significant difference ( P < 0.05), and hemifacial microsomia occurred ipsilaterally in patients with right-sided hearts.

CONCLUSIONS

Early situs inversus diagnosis is clinically important for patients and plastic surgeons. Further studies on anomalies associated with situs inversus will improve our understanding of their etiology.

Ear pinna growth and differentiation is conserved in murids and requires BMP signaling for chondrocyte proliferation

Despite being a major target of reconstructive surgery, development of the ear pinna remains poorly studied. Here, we provide a cellular characterization of late gestational and postnatal ear pinna development in two rodents and investigate the role of BMP5 in expansion and differentiation of auricular elastic cartilage. We find that ear pinna development is largely conserved between Mus musculus and the highly regenerative Acomys dimidiatus. The pattern of pre-cartilaginous cells is established early in development. These cells are specified into chondroblasts before ear unfolding and then undergo extensive proliferation before maturation. The elastic cartilage, connective tissue fibroblasts, dermal papilla and sheath cells, and adipocytes in the adult pinna are derived from cranial neural crest. Cellular analysis using the naturally occurring short ear mouse mutant shows that loss of BMP5 does not prevent specification of chondroblasts, but does impair chondroblast proliferation. Finally, chondroblast proliferation remains impaired in the adult mid-distal ear pinna of these mutants. Together, these data establish the developmental basis for differentiation of ear pinna tissues.

Single-Cell RNA sequencing reveals mitochondrial dysfunction in microtia chondrocytes

Microtia is a congenital malformation characterized by underdevelopment of the external ear. While chondrocyte dysfunction has been implicated in microtia, the specific cellular abnormalities remain poorly understood. This study aimed to investigate mitochondrial dysfunction in microtia chondrocytes using single-cell RNA sequencing. Cartilage samples were obtained from patients with unilateral, non-syndromic microtia and healthy controls. Single-cell RNA sequencing was performed using the 10 × Genomics platform. Bioinformatic analyses including cell type identification, trajectory analysis, and gene co-expression network analysis were conducted. Mitochondrial function was assessed through ROS levels, membrane potential, and transmission electron microscopy. Chondrocytes from microtia samples showed lower mitochondrial function scores compared to normal samples. Trajectory analysis revealed more disorganized differentiation patterns in microtia chondrocytes. Mitochondrial dysfunction in microtia chondrocytes was confirmed by increased ROS production, decreased membrane potential, and altered mitochondrial structure. Gene co-expression network analysis identified hub genes associated with mitochondrial function, including SDHA, SIRT1, and PGC1A, which showed reduced expression in microtia chondrocytes. This study provides evidence of mitochondrial dysfunction in microtia chondrocytes and identifies potential key genes involved in this process. These findings offer new insights into the pathogenesis of microtia and may guide future therapeutic strategies.

Epidemiological Characteristics and Maternal Risk Factors of Microtia and Aural Atresia in Kazakhstan

Introduction  Microtia and aural atresia present congenital ear anomalies that affect external ear and are associated with conductive hearing loss. Both anomalies result from exposure to various prenatal risk factors, most common during the first trimester of pregnancy. Objective  This study was aimed at epidemiological analysis of microtia/atresia and associated risk factors in the Kazakhstani population. Methods  A retrospective study in two stages. First, a cross-sectional analysis of microtia/ atresia frequencies from 2015 to 2019 on the basis of official statistics obtained from the Republican Centre for E-Health. Then, a case-control study was carried out to elucidate maternal risk factors associated with occurrence of microtia/atresia. We recruited patients presented in Almaty, Kazakhstan, between September 2021 and February 2022. Results  There was a substantial regional variation in the rates of both aural atresia and microtia/anotia. Mothers of children with microtia disclosed toxoplasmosis, other agents (including HIV, syphilis, varicella), rubella, cytomegalovirus, herpes simplex (TORCH) infections during pregnancy more often than those of healthy children (45.8 versus 7.3%; p  < 0.001). Exposure to different chemicals during pregnancy was mentioned more frequently by mothers of children with microtia when compared with the healthy controls (18.1 versus 8.1%; p  = 0.035). Self-reporting of alcohol consumption and intake of antibiotics was also significantly higher in mothers of children with microtia (31.9 and 36.1% respectively). Conclusion  Elucidation of microtia/atresia epidemiology is important due to their imposed social and economic burden, associated with treatment and rehabilitation costs.

Exploring mismatch negativity in children with congenital Microtia-Atresia: A Preliminary study

BACKGROUND

To investigate the characteristics of mismatch negativity (MMN) in terms of latency and amplitude in children with bilateral congenital microtia using a Bone conduction implant (Bonebridge), and to explore the relationship between cortical level auditory discrimination, speech perception, and psychosocial well-being.

METHODS

This descriptive, observational, cross-sectional study compared three groups: eight children with bilateral congenital microtia and Bonebridge implants (bilateral group), eight children with unilateral congenital microtia and no hearing aids (unilateral group), and eight children with normal hearing (NH group). Participants underwent MMN evaluation using a classic oddball paradigm with a pure tone burst stimulus, featuring a 1000 Hz standard stimulus and a 1200 Hz deviant stimulus, presented in a sound field at 65 dBHL. Additionally, speech perception tests, the Meaningful Use of Speech Scale (MUSS), and psychosocial status questionnaires, including the Social Anxiety Scale for Children (SASC) and the Children's Loneliness Scale (CLS), were administered to all subjects.

RESULTS

The bilateral group's average MMN latency was 241.23 ± 29.47 ms, and the unilateral group's was 209.96 ± 54.32 ms, both significantly longer than the NH group's 146.05 ± 15.73 ms (p < 0.0001, F=3.509, 95 % CI 68.09 to 122.3 and p = 0.0097, F=11.92, 95 % CI 18.07 to 109.8, respectively). However, no significant difference was found in MMN latency between the bilateral and unilateral groups (p = 0.202, F=3.397, 95 % CI -18.84 to 81.36). The unilateral group scored significantly higher on the MUSS (38.63 ± 1.41 vs. 30.75 ± 3.80, p = 0.0001, F=7.276, 95 % CI -11.16 to -4.590), had lower CLS scores (47.13 ± 8.13 vs. 58.25 ± 8.39, p = 0.024, F=1.065, 95 % CI 1.652 to 20.60), and lower SASC scores (4.13 ± 2.09 vs. 6.50 ± 2.25, p = 0.062, F=1.204, 95 % CI -0.138 to 4.89) compared to the bilateral group. MMN latency in the bilateral group correlated with SASC scores.

CONCLUSION

The MMN latency in congenital microtia patients may serve as an indicator of central auditory discrimination capabilities. In children with bilateral congenital microtia and Bonebridge implants, MMN latency can reflect social anxiety conditions to a certain degree.

Streamlining Asymmetry Quantification in Fetal Mouse Imaging: A Semi-Automated Pipeline Supported by Expert Guidance

Asymmetry is a key feature of numerous developmental disorders and in phenotypic screens is often used as a readout for environmental or genetic perturbations to normal development. A better understanding of the genetic basis of asymmetry and its relationship to disease susceptibility will help unravel the complex genetic and environmental factors and their interactions that increase risk in a range of developmental disorders. Large-scale imaging datasets offer opportunities to work with sample sizes needed to detect and quantify differences in morphology beyond severe deformities while also posing challenges to manual phenotyping protocols. In this work, we introduce a semi-automated open-source workflow to quantify abnormal asymmetry of craniofacial structures that integrates expert anatomical knowledge. We apply this workflow to explore the role of genes contributing to abnormal asymmetry by deep phenotyping 3D fetal microCT images from knockout strains acquired as part of the Knockout Mouse Phenotyping Program (KOMP2). Four knockout strains: Ccdc186, Acvr2a, Nhlh1, and Fam20c were identified with highly significant asymmetry in craniofacial regions, making them good candidates for further analysis into their potential roles in asymmetry and developmental disorders.

Predictors of 30-day complications, readmission, and postoperative length of stay in children undergoing autologous rib grafting for microtia

BACKGROUND

Predictors of outcomes in pediatric microtia surgery are not well understood within the current literature. A multi-institutional database study may reveal insights into these predictors.

OBJECTIVES

To explore the predictors of 30-day complications, 30-day readmission, and postoperative length of stay (PLOS) in pediatric microtia patients undergoing autologous rib grafting.

METHODS

The Pediatric National Surgical Quality Improvement Program was queried for details on patients with microtia (ICD-9/10 744.23/Q17.2) who underwent autologous rib grafting (CPT 21230) between 2012-2021. Demographics, comorbidities, inpatient status, 30-day complications, PLOS, and 30-day readmissions were analyzed. Statistical analyses were performed to compare the preoperative characteristics with postoperative outcomes.

RESULTS

Overall, 667 patients met the inclusion criteria. Sixty-three (9.4%) had at least one complication, and 19 (2.9%) were readmitted. Univariate analysis showed that inpatient status (p = 0.011) and race (p = 0.023) were associated with higher complication rates. Multivariate analysis revealed that outpatient status was associated with significantly lower odds of complications (OR: 0.49, 95% CI [0.27, 0.87], p = 0.018), and developmental delay was associated with higher odds of 30-day readmission (OR: 2.80, 95% CI [1.05, 7.17], p = 0.036). Longer operative time was associated with older age (13.9% increase per five-year age increase, p < 0.001) and inpatient status (35.3% increase, p < 0.001). PLOS was shorter for outpatients (45.45% shorter, p < 0.001) and cases performed by plastic surgeons (14.2% shorter, p < 0.001).

CONCLUSION

Microtia reconstruction using autologous cartilage is a relatively safe procedure with low complication and readmission rates. Significant predictors of postoperative outcomes include inpatient status, race, developmental delay, and age. These findings highlight the importance of considering these factors in surgical planning and patient counseling.

Rare Combination of Congenital Microtia and Limb Malformations: Analysis of Etiology and Treatment

ABSTRACT

Congenital microtia is the second most common congenital craniofacial deformity, and limb malformation is the most common birth defect. The combination of the 2 deformities is rare. In this study, the authors present 3 cases with a rare combination of congenital microtia and limb malformations and analyze the etiology and treatment of the malformations. There may be genetic homology between these two malformations, and they can be associated with abnormal ectodermal migration.

LEVEL OF EVIDENCE

Level IV-case study.

Audiological and Subjective Benefits in a Child with Microtia and Atresia After Sequential Bilateral Implantation with Active Bone Conduction Devices: A Case Study

BACKGROUND

With bilateral hearing loss, the main problems for the patient are speech understanding in noise and, especially in asymmetrical hearing loss, an inability to correctly localize sound sources. There are multiple methods of treatment and rehabilitation for people with conductive hearing loss, and one of them is to use an active bone conduction implant. This case study is designed to evaluate the auditory benefits and sound localization accuracy with active bilateral bone conduction implants-in comparison to unilateral ones-in a patient with congenital bilateral conductive hearing loss caused by a congenital malformation. We assess subjective and audiological benefits (functional, directional hearing, speech comprehension in quiet and noise).

CASE REPORT

This study describes the results in a 15-year-old patient with bilateral congenital malformation of the outer ears and associated conductive hearing loss who was treated with two Bonebridge active bone conduction implants. Speech recognition ability, hearing thresholds, and sound localization were tested under three conditions: unaided, unilateral on the right-side, and bilateral on both sides. The patient filled in an Abbreviated Profile of Hearing Aid Benefit questionnaire (APHAB) to evaluate limitations in daily life caused by hearing impairment. The results show an improvement in free-field hearing thresholds and the ability to discriminate speech, both in quiet and in noise after implantation. Subjectively, the patient had significantly fewer problems with two implants than with one (or with no implant) in terms of hearing in everyday situations.

CONCLUSIONS

Unilateral use of the Bonebridge device in a patient with congenital bilateral conductive hearing loss did not provide full benefits. However, bilateral implantation improved speech understanding in noise and sound localization.

Drug-associated congenital anomalies of the external ear identified in the United States food and drug administration adverse event reporting system database

Congenital anomalies of the external ear can have a significant impact on a child's development and quality of life. While genetic factors play a crucial role in the etiology of these anomalies, environmental factors such as drug exposure during pregnancy may also contribute to their occurrence. This study aims to investigate the association between drug exposure and congenital anomalies of the external ear using data from an adverse drug reaction report database. Using OpenVigil 2.1, we queried the FAERS database to retrieve adverse event reports from the first quarter of 2004 to the first quarter of 2024. To identify relevant cases, we used Medical Dictionary for Regulatory Activities terms focusing on congenital anomalies of the external ear. Drug generic names were sourced from the DrugBank database. To assess safety signals and rank drugs by their signal strength, we conducted a disproportionality analysis, generating reporting odds ratios (ROR) and proportional reporting ratios (PRR). A total of 20,754,281 AE reports were identified in the FAERS database from Q1 2004 to Q1 2024, of which 1763 were related to congenital anomalies of the external ear. Valproic acid (122 cases) was associated with the most cases, followed by mycophenolate mofetil (105 cases) and lamotrigine (65 cases). According to the disproportionality analysis, the top five drugs with the highest ROR and PRR were primidone (ROR: 397.05, 95% CI 147.21, 1070.9; PRR: 388.71, 95% CI 145.89, 1035.7), valproic acid (ROR: 239.46, 95% CI 123.75, 463.37; PRR: 236.42, 95% CI 123.82, 451.43), tapazole (ROR: 198.35, 95% CI 63.49, 619.67; PRR: 196.25, 95% CI 62.97, 611.67), nevirapine (ROR: 138.24, 95% CI 82.9, 230.51; PRR: 137.23, 95% CI 82.44, 228.44), and sebivo (ROR: 117.1, 95% CI 48.51, 282.67; PRR: 116.37, 95% CI 48.17, 281.12). This study identified several drugs significantly associated with congenital anomalies of the external ear in the FAERS database using disproportionality analysis. The findings can help healthcare professionals better recognize and manage drug-induced congenital anomalies of the external ear, particularly when prescribing high-risk medications. Further research is needed to elucidate the mechanisms underlying these associations and develop strategies for preventing and mitigating drug-induced congenital anomalies of the external ear.

Comparison of total prevalence, perinatal prevalence, and livebirth prevalence of birth defects in Hunan Province, China, 2016-2020

Objective

Birth defect of any type is undesirable and often pose a negative impact on the health and development of the newborn. Birth defects surveillance with datasets from surveillance health-related programs are useful to predict the pattern of birth defects and take preventive measures. In this study, the total prevalence, perinatal prevalence, and livebirth prevalence of birth defects were compared.

Methods

Data were obtained from the Birth Defects Surveillance System in Hunan Province, China, 2016-2020. The total prevalence is the number of birth defects (including livebirths, stillbirths, and selective terminations of pregnancy) per 1,000 births (including livebirths and stillbirths). The perinatal prevalence is the number of birth defects (between 28 weeks gestation and 7 days postpartum) per 1,000 births. The livebirth prevalence is the number of liveborn birth defects per 1,000 births (unit: ‰). Underestimated proportion (unit: %) is the reduction level of perinatal prevalence or livebirth prevalence compared to the total prevalence. Prevalence with 95% confidence intervals (CI) was calculated using the log-binomial method. Chi-square tests (χ 2) were used to examine if significant differences existed in prevalence or underestimated proportion between different groups.

Results

A total of 847,755 births were included in this study, and 23,420 birth defects were identified, including 14,459 (61.74%) birth defects with gestational age > =28 weeks, and 11,465 (48.95%) birth defects in livebirths. The total prevalence, perinatal prevalence, and livebirth prevalence of birth defects were 27.63‰ (95%CI, 27.27-27.98), 17.06‰ (95%CI, 16.78-17.33), and 13.52‰ (95%CI, 13.28-13.77), respectively, and significant differences existed between them (χ2  = 4798.55, p < 0.01). Compared to the total prevalence, the perinatal prevalence and livebirth prevalence were underestimated by 38.26 and 51.05%, respectively. Significant differences existed between the total prevalence, perinatal prevalence, and livebirth prevalence of birth defects in all subgroups according to year, sex, residence, and maternal age (p < 0.05). Significant differences existed between the total prevalence, perinatal prevalence, and livebirth prevalence for 17 specific defects: congenital heart defect, cleft lip-palate, Down syndrome, talipes equinovarus, hydrocephalus, limb reduction, cleft lip, omphalocele, anal atresia, anencephaly, spina bifida, diaphragmatic hernia, encephalocele, gastroschisis, esophageal atresia, bladder exstrophy, and conjoined twins (p < 0.05). In comparison, no significant difference existed between the total prevalence, perinatal prevalence, and livebirth prevalence for 6 specific defects: polydactyly, other external ear defects, syndactyly, hypospadias, cleft palate, and anotia/microtia (p > 0.05).

Conclusion

The total prevalence and livebirth prevalence of birth defects in Hunan Province, China, was not well studied. A systematic study was conducted to compare the total prevalence, perinatal prevalence, and livebirth prevalence of birth defects. The study reveals that significant differences existed between the total prevalence, perinatal prevalence, and livebirth prevalence of birth defects (including many specific defects), and year, sex, residence, and maternal age had significant impacts on it. The outcomes of the study will help to take preventive measures for birth defects as well as benefit the people involving public health and policymakers to improve the current scenario.

Pharyngeal Arches, Chapter 2: Ear and Neck Abnormalities

The pharyngeal arches are the foundation of face and neck development. Impaired development of these embryologic structures can result in craniofacial abnormalities. Surgeons who manage head and neck pathology will invariably encounter conditions associated with aberrant pharyngeal arch anatomy, and a thorough understanding of the normal development of these structures is paramount to accurate diagnosis and treatment. This manuscript is the second of a four-part series written for plastic surgeons, focusing on the abnormal development of pharyngeal arches leading to pathologic ear and neck anomalies seen in clinical practice.

Establishing an International Interdisciplinary Research Network in Craniofacial Microsomia: The CARE Program

OBJECTIVE

Craniofacial microsomia (CFM) is a broad clinical term used to describe a congenital condition most commonly involving the underdevelopment of the external ear, mandible, soft tissues, and facial nerve. Despite medical advances, understanding of the psychological health and healthcare experiences of individuals with CFM and their caregivers remains limited. This article describes a research program designed to address these knowledge gaps, and identify opportunities for psychosocial intervention and improved healthcare provision.

DESIGN

The Craniofacial microsomia: Accelerating Research and Education (CARE) research program aims to: 1) Conduct up to 160 narrative interviews with individuals and caregivers to validate a conceptual framework; 2) Administer an online international survey of up to 800 individuals with CFM and caregivers to identify predictors of psychological distress; 3) Perform up to 60 semi-structured interviews with healthcare providers and advocacy leaders to examine the extent to which current healthcare provisions address identified patient needs; and 4) Establish a participant registry to build a longitudinal database and develop an international community.

RESULTS

Teams in the USA and UK have been established, alongside an international, interdisciplinary Advisory Committee. Data analysis for Aim 1 is ongoing and informing the delivery of Aims 2-3. Aim 4 is also in development. A dedicated website serves as a recruitment tool, educational resource, and mechanism for engaging with the CFM community.

CONCLUSIONS

The CARE program provides a comprehensive approach to understanding the experiences of individuals with CFM and their caregivers. Challenges encountered and lessons learned are shared for the benefit of the community.

Clinical evaluation of temporal bone anatomical abnormalities and surgical method selection in patients with congenital aural atresia

OBJECTIVES

To analyze anatomic variations of the temporal bone in congenital aural atresia (CAA) and their correlation with the Jahrsdoerfer score, in order to guide clinical selection of surgical treatment methods.

MATERIAL AND METHODS

We retrospectively studied 53 patients (72 ears) with unilateral or bilateral CAA, including 34 ears with normal hearing as controls. Audiological and imaging data were collected and analyzed. We evaluated the Jahrsdoerfer score and anatomical variations, including tegmen mastoideum position, anterior sigmoid sinus displacement, and elevated jugular bulb.

RESULTS

The average air conduction hearing threshold (PTA4) ranged from 0.5 to 4 kHz was 65.48 ± 8.19 dBHL, with an average Jahrsdoerfer score of 4.93 ± 2.78. In CAA group, there was a higher prevalence and severity of anterior sigmoid sinus and low position of the tegmen mastoideum (P < 0.01). However, there was no significant difference in incidence rates among groups with high jugular bulb (P > 0.05). Anterior sigmoid sinus and high jugular bulb showed no correlation with the Jahrsdoerfer score, while the low position of the tegmen mastoideum had a weak correlation. The Jahrsdoerfer score did not adequately predict temporal bone anatomical abnormalities in CAA patients.

CONCLUSION

CAA exhibit a higher incidence and greater severity of temporal bone anatomical abnormalities compared to the control group, and the Jahrsdoerfer score inadequately assesses these abnormalities. Anomalies like low position of the tegmen mastoideum, anterior sigmoid sinus, and high jugular bulb should also be considered as independent factors influencing surgical decisions for atresiaplasty.

Multiple cranial pathologies in spotted hyaenas, Crocuta crocuta

Spotted hyaenas are generally considered to have resilience against injuries and pathogens, and the incidence of pathologies is scarcely reported. However, it is important for ecological studies and conservation efforts to have a clear overview of the physical threats that can occur in the life of a species. The present paper describes and interprets several osteopathologies in the crania of the spotted hyaena, Crocuta crocuta, in the collections of the Royal Museum for Central Africa (RMCA) in Tervuren, Belgium. Of the fifty-two specimens from central Africa examined, twenty-three (i.e., 44 %) of them showed evidence of pathologies, including injuries, congenital pathologies, and disease. Selected specimens were scanned using Computed Tomography and their internal cranial structures were studied. Here we describe and discuss the different types of pathologies evident in the crania of these hyaenas: craniosynostosis, microtia, osteomyelitis and periodontitis, as well as a trauma indicated by cranial fractures, dental fractures, and bite puncture marks. Some pathologies reported herein are novel for hyaenas, and there are some instances of multiple pathologies in the same individual. Implications of these pathologies, including the social interactions of hyenas, conservational threats, as well as biased data sampling, are highlighted. This study improves our knowledge of disease and trauma experienced by hyaenids, and provides a better understanding of their biology, and the potential threats faced by these iconic animals. This case study offers a comparative base for similar studies in other carnivorans, to clarify the pathological background of apex predators.

Genetic Testing in Craniofacial Care: Development of Algorithms for Testing Patients with Orofacial Clefting, Branchial Arch Anomalies, and Craniosynostosis

OBJECTIVE

To develop consensus-based algorithms for genetic testing in patients with common craniofacial conditions.

DESIGN

An online collaborative consisting of online meetings, independent work, and feedback across groups. Setting/Participants: A collaborative of genetics and pediatrics providers from three regional craniofacial centers (four institutions).

METHODS

Collaborative participants agreed upon a shared initial framework, developed algorithms independently, and presented/tested the algorithms with a national audience. Algorithms were modified based on consensus feedback.

RESULTS

The collaborative group developed final algorithms for genetic testing in patients with orofacial cleft, branchial arch conditions, and craniosynostosis.

CONCLUSIONS

Timely and accurate diagnosis of genetic conditions can support medical management recommendations that result in safer surgical interventions. Algorithms can help guide best-practices for testing, particularly in institutions without easy access to genetics providers.

A new active bone-conduction implant: surgical experiences and audiological outcomes in patients with bilateral congenital microtia

PURPOSE

First-generation bone bridges (BBs) have demonstrated favorable safety and audiological benefits in patients with conductive hearing loss. However, studies on the effects of second-generation BBs are limited, especially among children. In this study, we aimed to explore the surgical and audiological effects of second-generation BBs in patients with bilateral congenital microtia.

METHODS

This single-center prospective study included nine Mandarin-speaking patients with bilateral microtia. All the patients underwent BCI Generation 602 (BCI602; MED-EL, Innsbruck, Austria) implant surgery between September 2021 and June 2023. Audiological and sound localization tests were performed under unaided and BB-aided conditions.

RESULTS

The transmastoid and retrosigmoid sinus approaches were implemented in three and six patients, respectively. No patient underwent preoperative planning, lifts were unnecessary, and no sigmoid sinus or dural compression occurred. The mean function gain at 0.5-4.0 kHz was 28.06 ± 4.55-dB HL. The word recognition scores improved significantly in quiet under the BB aided condition. Signal-to-noise ratio reduction by 10.56 ± 2.30 dB improved the speech reception threshold in noise. Patients fitted with a unilateral BB demonstrated inferior sound source localization after the initial activation.

CONCLUSIONS

Second-generation BBs are safe and effective for patients with bilateral congenital microtia and may be suitable for children with mastoid hypoplasia without preoperative three-dimensional reconstruction.

Histological assessment of microtia cartilage, a potential source of autograft tissue in ear reconstruction

Cartilage is a strong and flexible connective tissue that has many forms and functions in our body. While cartilage exhibits some forms of limited repair, for the most part, it is not particularly regenerative. Thus, in situations where patients require cartilage reconstruction, surgeons may use autografts to replace missing or damaged tissue. Cartilage tissues from different regions of the body exhibit histological differences and are in limited supply. Thus, it is important to characterize these differences to determine the most appropriate autograft source. In the case of microtia, a congenital deformity where the pinna is underdeveloped, reconstruction commonly utilizes cartilage sourced from a patient's own costal cartilage. This presents a potential morbidity risk. In this study, we evaluate the histological characteristics of microtia cartilage compared with normal auricular and costal cartilage obtained from human patients undergoing surgical resection. Histochemistry was used to evaluate cellularity, lipid content, and ECM content. Using a Bayesian statistical approach, we determined that while costal cartilage is the standard tissue donor, the microanatomy of microtia cartilage more closely reflects normal auricular cartilage than costal cartilage. Therefore, microtia cartilage may serve as an additional reservoir for cartilage during reconstruction.

The impact of national health insurance on the cost of auricular reconstruction with skin expansion for microtia in China: A single-center retrospective study based on 1290 surgeries

BACKGROUND

Congenital microtia presents challenges that encompass physical disabilities and psychosocial distress. It is reported that people with low income have a higher possibility of giving birth to babies with congenital malformations. At the end of June 2023, auricular reconstruction was partially incorporated into national health insurance in our hospital.

METHODS

Briefly, 1290 surgeries, including stage-I and stage-II auricular reconstruction with tissue expansion were performed in 2023, involving 779 patients. Patient data, including age, sex, length of stay, residence, and costs, were retrieved from the electronic medical record system. The final cost before and after health insurance coverage, as well as the medical insurance reimbursement ratio in each province and municipality were statistically analyzed.

RESULTS

Following insurance coverage, a significant increase in the number of surgeries was observed (514 [39.84%] vs. 776 [60.16%], χ2 = 45.99, p = 0.000), with notable reductions in out-of-pocket costs for unilateral and bilateral stage-I and -II auricular reconstructions ($3915.01 vs. $6645.28, p < 0.05; $11546.80 vs. $5198.08, p < 0.05). Disparities in reimbursement rates across regions were evident, but showed no correlation to the local GDP per capita. There was a positive correlation between the length of stay and inpatient cost. Patient's age was not related to the inpatient cost, but to the length of stay.

CONCLUSION

The health insurance coverage for microtia treatment significantly alleviated financial burdens on the patients' family and increased the number of auricular reconstruction surgeries. These findings underscore the critical role of insurance coverage in enhancing healthcare accessibility and affordability for patients with congenital microtia.

Demographic, Functional, and Risk Factors Characterization in Ecuadorian Mestizo Patients With Microtia: A Retrospective Study

OBJECTIVE

This paper compares demographic, morphological, functional, and risk factors between isolated and familial forms of microtia in Ecuadorian mestizo patients.

METHODS

The authors did an epidemiological, and retrospective study with 112 patients divided into isolated microtia (n = 91) and familial microtia (n = 21). Patients with syndromic microtia were not included.

RESULTS

In isolated microtia, the mean age was 11.80 ± 16.9, and the most prevalent age group was from 5 to 9 years, with 45.0%; males were 58.2%, and 91.2% of patients were born in a city above 2500 meters about sea level. In familial microtia, the mean age was 15.57 ± 17.2. There were no statistically significant differences between the analyzed variables. In isolated microtia, 41.8% of patients had bilateral involvement, 40.7% had grade 1 microtia in the right ear (RE), and grade 1 in the left ear was 47.3%; external auditory canal atresia of RE was present in 62.6%, and in left ear in 31.6%. External auditory canal atresia sidedness was mostly unilateral in both groups. Most patients did not have tags or pits (78% and 81% in RE and 85.7% and 71.4%). Most patients had moderate hearing loss in both ears.

CONCLUSION

The authors found an association between both microtia forms with external auditory canal atresia in RE; only 20% of patients had unilateral auricular tags or pits in both groups. The authors also found a high incidence (18.75%) of familial microtia, which suggests a distinct pathological genetic component than the more prevalent isolated cases. The authors found a high association of microtia cases from the Ecuadorian highlands above 2500 meters about sea level (over 90%). The presence of "social" intake of alcohol during pregnancy showed over twice the chance of having a child born with microtia.

Comprehensive analysis of donor-site chest deformities after autologous costal cartilage microtia reconstruction: A systematic review

BACKGROUND

Autologous costal cartilage has gained widespread acceptance as an important material for ear reconstruction in patients with microtia. Despite its recognition as being "worth the trade-off," attention should be directed toward donor-site deformities. This systematic review focused on existing English literature related to microtia reconstruction and aimed to reveal the incidence of chest wall deformities and assess the effectiveness of the various proposed surgical techniques aimed at reducing donor-site morbidities.

METHODS

A comprehensive search was conducted on Pubmed and OVID using the keywords "microtia," and "chest deformity" or "rib harvest." Articles were screened based on predefined inclusion and exclusion criteria. Data acquisition encompassed patient demographics, employed surgical techniques, methods for evaluating chest deformity, and incidence of associated complications.

RESULTS

Among the 362 identified articles, 21 met the inclusion criteria. A total of 2600 cases involving 2433 patients with microtia were analyzed in this review. Perichondrium preservation during cartilage harvesting led to a significant reduction in chest deformities. However, the wide incidence range (0% to 50%) and the lack of specific assessment methods suggested potential underestimation. Computed tomography revealed reduced chest wall growth in the transverse and sagittal directions, resulting in decreased thoracic area. Innovative surgical techniques have shown promising results in reducing chest deformities.

CONCLUSIONS

Although a quantitative analysis was not feasible, objective evidence of deformities was established through computed tomography scans. This analysis highlighted the need for dedicated studies with larger sample sizes to further advance our understanding of chest wall deformities in microtia reconstruction.

The Quality and Readability of Online Patient Information on Positional Head Shape Conditions

OBJECTIVE

Families increasingly use online resources to acquire medical information about their child's condition with little understanding of the legitimacy of the source of information or of the information itself. We evaluate the quality and readability of online information related to positional head shape conditions and identify unmet needs for healthcare providers to improve online patient education.

DESIGN

The search terms "flat head baby," "brachycephaly," and "plagiocephaly" were queried on the Google search engine and the first 20 websites for each were reviewed. Included websites were evaluated for quality using the DISCERN Instrument and readability using the Flesch-Kincaid Reading Grade Level (FKGL) and Flesch Reading Ease Score (FRES). Websites were categorized by upload source and results were compared using one-way ANOVA.

RESULTS

38 websites met inclusion criteria. There was no significant correlation between DISCERN score and Google search rank between the three search terms. Professional organizations provided websites with the highest mean DISCERN score (56.3) and commercial websites with the lowest score (36.6, P = .003), indicating "good" and "poor" quality content, respectively. Readability assessments showed an overall average FKGL of 9.9 and FRES of 54.4, suggesting "fairly difficult". Hospitals provided the most website results and tended to publish lower quality information, yet are the most readable.

CONCLUSIONS

High quality websites written at an appropriate reading level for the general public are lacking. A review of online resources for positional head shape conditions can be used to derive recommendations to improve the content of online patient education for pediatric healthcare.

Early Non-Surgical Treatment For Microtia Types 1 and 2

Esthetic concerns and psychosocial distress often accompany auricular deformities and malformations in both children and their parents. Approximately 30% of newborns are affected by auricular anomalies, with 15% to 20% resulting in permanent defects. While surgical intervention is typically considered the gold standard for malformations, a non-surgical approach, such as splinting, molding, or other non-invasive techniques, can effectively address deformations if promptly administered by a specialist. Microtia, classified into 4 types, presents challenges ranging from fundamental structural anomalies in types 1 and 2 to severe defects in type 3 and complete absence of the external ear in type 4 (anotia). This study introduces a novel non-invasive treatment modality for microtia types 1 and 2. The cohort consisted of 5 newborns treated for microtia types 1 or 2 between 2022 and 2023. Utilizing the EarWell system, treatment was initiated before 3 weeks of age (mean age: 2 weeks), with an average treatment duration of 6.6 weeks, supplemented by molding treatment as needed. Minor adverse effects, such as simple dermatitis, were observed in 2 patients. All parents expressed high satisfaction with the esthetic outcomes, with 60% reporting extreme satisfaction. The prompt initiation of the treatment protocol for microtia types 1 and 2 led to outstanding and timely outcomes in infants, enhancing the quality of life for both parents and their children. Early intervention for subsequent treatment may improve the condition and, in certain cases, serve as a satisfactory alternative for parents hesitant about further surgical intervention for their children.

Correlation of Grading and Number of Ear Subunits With Auditory Brainstem Response Findings in Children With Microtia

PURPOSE

The association between microtia severity and hearing function has been thoroughly investigated. This study examined the relationship between microtia grade, number of ear subunits (i.e., helix, antihelix, scapha, triangularis fossa, concha, lobule, tragus, and antitragus) with auditory brainstem response (ABR) findings in children with microtia.

STUDY DESIGN

A retrospective chart review was employed in this study.

METHOD

We analyzed the ABR test results and photographs of 22 children with 30 microtia ears at Dr. Cipto Mangunkusumo National Hospital, Jakarta. The ABR test results were acquired using click (air conduction only) and 500-Hz tone burst stimuli (air- and bone-conduction). Ear photographs were overlaid with a template of a normal ear to determine the number of ear subunits present and the subsequent microtia grade. Number of ear subunits and ABR results were analyzed using the chi-square, Mann-Whitney U, and Spearman's correlation tests.

RESULTS

ABR thresholds for click and 500-Hz tone bursts air-conduction were significantly poorer for ears with a subunit < 5 compared to ears with a subunit ≥ 5. No significant difference was observed in 500 Hz bone-conduction ABR thresholds between these groups. Correlation analysis showed a significant negative correlation between increased ear subunits and click ABR thresholds. No significant correlation was found between ear subunits and 500-Hz air- and bone-conduction ABR thresholds.

CONCLUSIONS

A higher number of ear subunits are associated with a lower hearing threshold, as assessed using ABR with click stimuli. Therefore, the number of ear subunits and microtia grades can be used to examine the hearing level thresholds in infants and children with microtia.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25669440.

A Systematic Review of the Application of Computational Technology in Microtia

Microtia is a congenital and morphological anomaly of one or both ears, which results from a confluence of genetic and external environmental factors. Up to now, extensive research has explored the potential utilization of computational methodologies in microtia and has obtained promising results. Thus, the authors reviewed the achievements and shortcomings of the research mentioned previously, from the aspects of artificial intelligence, computer-aided design and surgery, computed tomography, medical and biological data mining, and reality-related technology, including virtual reality and augmented reality. Hoping to offer novel concepts and inspire further studies within this field.

Remaining microtia tissue as a source for 3D bioprinted elastic cartilage tissue constructs, potential use for surgical microtia reconstruction

The absence of ears in children is a global problem. An implant made of costal cartilage is the standard procedure for ear reconstruction; however, side effects such as pneumothorax, loss of thoracic cage shape, and respiratory complications have been documented. Three-dimensional (3D) printing allows the generation of biocompatible scaffolds that mimic the shape, mechanical strength, and architecture of the native extracellular matrix necessary to promote new elastic cartilage formation. We report the potential use of a 3D-bioprinted poly-ε-caprolactone (3D-PCL) auricle-shaped framework seeded with remaining human microtia chondrocytes for the development of elastic cartilage for autologous microtia ear reconstruction. An in vivo assay of the neo-tissue formed revealed the generation of a 3D pinna-shaped neo-tissue, and confirmed the formation of elastic cartilage by the presence of type II collagen and elastin with histological features and a protein composition consistent with normal elastic cartilage. According to our results, a combination of 3D-PCL auricle frameworks and autologous microtia remnant tissue generates a suitable pinna structure for autologous ear reconstruction.

Intelligence among ear deformities and cleft lip and/or alveolus and/or cleft palate patients during 50 years in Israel

PURPOSE

We evaluated hearing loss and general intelligence among persons with auricle anomalies and cleft lip and/or alveolus and/or cleft palate (CLAP).

METHODS

A nationwide cross-sectional study of data recorded during 1966-2019, as mandatory pre-military recruitment of individuals.

RESULTS

Of 3 182 892 adolescents, 548 were diagnosed with auricle anomalies and 2072 with CLAP. For the latter, the adjusted odds ratios for the low, low to medium and medium general intelligence categories compared to the highest category were 1.4 [95% CI 1.5-1.2], 1.2 [95% CI 1.4-1.1] and 1.1 [95% CI 1.2-0.9] respectively. The corresponding values for the auricle anomalies were not significant.

CONCLUSIONS

General intelligence was impaired among individuals with CLAP, but no significant correlation was found among individuals suffering from auricle anomalies.

Tablet-based Augmented reality and 3D printed templates in fully guided Microtia Reconstruction: a clinical workflow

BACKGROUND

Microtia is a congenital malformation of the auricle that affects approximately 4 of every 10,000 live newborns. Radiographic film paper is traditionally employed to bidimensionally trace the structures of the contralateral healthy ear in a quasi-artistic manner. Anatomical points provide linear and angular measurements. However, this technique proves time-consuming, subjectivity-rich, and greatly dependent on surgeon expertise. Hence, it's susceptible to shape errors and misplacement.

METHODS

We present an innovative clinical workflow that combines 3D printing and augmented reality (AR) to increase objectivity and reproducibility of these procedures. Specifically, we introduce patient-specific 3D cutting templates and remodeling molds to carve and construct the cartilaginous framework that will conform the new ear. Moreover, we developed an in-house AR application compatible with any commercial Android tablet. It precisely guides the positioning of the new ear during surgery, ensuring symmetrical alignment with the healthy one and avoiding time-consuming intraoperative linear or angular measurements. Our solution was evaluated in one case, first with controlled experiments in a simulation scenario and finally during surgery.

RESULTS

Overall, the ears placed in the simulation scenario had a mean absolute deviation of 2.2 ± 1.7 mm with respect to the reference plan. During the surgical intervention, the reconstructed ear was 3.1 mm longer and 1.3 mm wider with respect to the ideal plan and had a positioning error of 2.7 ± 2.4 mm relative to the contralateral side. Note that in this case, additional morphometric variations were induced from inflammation and other issues intended to be addressed in a subsequent stage of surgery, which are independent of our proposed solution.

CONCLUSIONS

In this work we propose an innovative workflow that combines 3D printing and AR to improve ear reconstruction and positioning in microtia correction procedures. Our implementation in the surgical workflow showed good accuracy, empowering surgeons to attain consistent and objective outcomes.

A 76-base pair duplication within the enhancer region of the HMX1 gene causes sheep microtia

Sheep congenital microtia is characterized by underdeveloped ears and provides an ideal basis for studying human microtia. This study identified the causal mutation and regulatory mechanisms underlying this disorder. Whole-genome association analysis was conducted using 23 ear tissue samples from sheep with microtia and 28 samples from normal-eared sheep. A significant correlation was found between microtia and a 76-base pair duplication in the enhancer region of the HMX1 gene. Further analysis of offspring phenotypes confirmed an autosomal dominant inheritance pattern. Genotypic analysis showed that individuals that are homozygous for this duplication were earless, heterozygous individuals exhibited shortened ears, and wild-type individuals had normal ears. Moreover, luciferase assays confirmed that this duplication increased HMX1 gene expression, and duplication knock-in mice also exhibited shorter and narrower external ears compared to wild-type mice. Transcriptomic analysis further demonstrated that this duplication enhanced HMX1 gene expression in animal models. This study characterized the causal regulatory mutation underlying sheep microtia.

Multi-omics analysis of a case of congenital microtia reveals aldob and oxidative stress associated with microtia etiology

BACKGROUND

Microtia is reported to be one of the most common congenital craniofacial malformations. Due to the complex etiology and the ethical barrier of embryonic study, the precise mechanisms of microtia remain unclear. Here we report a rare case of microtia with costal chondrodysplasia based on bioinformatics analysis and further verifications on other sporadic microtia patients.

RESULTS

One hundred fourteen deleterious insert and deletion (InDel) and 646 deleterious SNPs were screened out by WES, candidate genes were ranked in descending order according to their relative impact with microtia. Label-free proteomic analysis showed that proteins significantly different between the groups were related with oxidative stress and energy metabolism. By real-time PCR and immunohistochemistry, we further verified the candidate genes between other sporadic microtia and normal ear chondrocytes, which showed threonine aspartase, cadherin-13, aldolase B and adiponectin were significantly upregulated in mRNA levels but were significantly lower in protein levels. ROS detection and mitochondrial membrane potential (∆ Ψ m) detection proved that oxidative stress exists in microtia chondrocytes.

CONCLUSIONS

Our results not only spot new candidate genes by WES and label-free proteomics, but also speculate for the first time that metabolism and oxidative stress may disturb cartilage development and this might become therapeutic targets and potential biomarkers with clinical usefulness in the future.

Phenotypic and genetic analysis of children with unexplained neurodevelopmental delay and neurodevelopmental comorbidities in a Chinese cohort using trio-based whole-exome sequencing

BACKGROUND

Trio-based whole-exome sequencing (trio-WES) enables identification of pathogenic variants, including copy-number variants (CNVs), in children with unexplained neurodevelopmental delay (NDD) and neurodevelopmental comorbidities (NDCs), including autism spectrum disorder (ASD), epilepsy, and attention deficit hyperactivity disorder. Further phenotypic and genetic analysis on trio-WES-tested NDD-NDCs cases may help to identify key phenotypic factors related to higher diagnostic yield of using trio-WES and novel risk genes associated with NDCs in clinical settings.

METHODS

In this study, we retrospectively performed phenotypic analysis on 163 trio-WES-tested NDD-NDCs children to determine the phenotypic differences between genetically diagnosed and non-genetically diagnosed groups. Additionally, we conducted genetic analysis of ASD genes with the help of Simons Foundation for Autism Research Institute (SFARI) Gene database to identify novel possible ASD-risk genes underlying genetic NDD conditions.

RESULTS

Among these 163 patients, pathogenic variants were identified in 82 cases (82/163, 50.3%), including 20 cases with CNVs. By comparing phenotypic variables between genetically diagnosed group (82 cases) and non-genetically diagnosed group (81 cases) with multivariate binary logistic regression analysis, we revealed that NDD-NDCs cases presenting with severe-profound NDD [53/82 vs 17/81, adjusted-OR (95%CI): 4.865 (2.213 - 10.694), adjusted-P < 0.001] or having multiple NDCs [26/82 vs 8/81, adjusted-OR (95%CI): 3.731 (1.399 - 9.950), adjusted-P = 0.009] or accompanying ASD [64/82 vs 35/81, adjusted-OR (95%CI): 3.256 (1.479 - 7.168), adjusted-P = 0.003] and head circumference abnormality [33/82 vs 11/81, adjusted-OR (95%CI): 2.788 (1.148 - 6.774), adjusted-P = 0.024] were more likely to have a genetic diagnosis using trio-WES. Moreover, 37 genes with monogenetic variants were identified in 48 patients genetically diagnosed with NDD-ASD, and 15 dosage-sensitive genes were identified in 16 individuals with NDD-ASD carrying CNVs. Most of those genes had been proven to be ASD-related genes. However, some of them (9 genes) were not proven sufficiently to correlate with ASD. By literature review and constructing protein-protein interaction networks among these 9 candidate ASD-risk genes and 102 established ASD genes obtained from the SFARI Gene database, we identified CUL4B, KCNH1, and PLA2G6 as novel possible ASD-risk genes underlying genetic NDD conditions.

CONCLUSIONS

Trio-WES testing is recommended for patients with unexplained NDD-NDCs that have severe-profound NDD or multiple NDCs, particularly those with accompanying ASD and head circumference abnormality, as these independent factors may increase the likelihood of genetic diagnosis using trio-WES. Moreover, NDD patients with pathogenic variants in CUL4B, KCNH1 and PLA2G6 should be aware of potential risks of developing ASD during their disease courses.

Stakeholders' Views on Information Needed in a Patient Decision Aid for Microtia Reconstruction

OBJECTIVE

To assess which information about microtia and the possible reconstructive options health care providers (HCPs), patients and parents believe should be included in a patient decision aid (PtDA).

DESIGN

A mixed-methods study comprised of an online survey of HCPs and focus group discussions with patients and parents.

PARTICIPANTS

Survey respondents were members of the International Society for Auricular Reconstruction (ISAR). Focus group participants were patients with microtia and their parents, recruited through the microtia outpatient clinic at Amsterdam UMC, and through a Dutch patient organization for cleft and craniofacial conditions.

METHODS

An online, investigator-made survey was sent to ISAR members in December 2021. Semi-structured focus group discussions were held in February 2022. Quantitative results were summarized, and qualitative results were thematically grouped.

RESULTS

Thirty-two HCPs responded to the survey (response rate 41%). Most respondents (n = 24) were plastic surgeons, who had a median of 15 years of experience (IQR: 7-23 years). Two focus groups were held with a total of five patients and two parents. HCPs, patients and parents generally agreed on the information needed in a PtDA, emphasizing the importance of realistic expectation management. Patients and parents also considered psychosocial and functional outcomes, patient experiences, as well as patients' involvement in decision-making important.

CONCLUSIONS

A PtDA for microtia reconstruction should target all patients with microtia, and include information on at least technique-related information, expected esthetic results, possible adverse effects, psychosocial and functional outcomes and patient experiences. Preference eliciting questions should be developed for both pediatric patients and their parents.

Bioengineering Full-scale auricles using 3D-printed external scaffolds and decellularized cartilage xenograft

Reconstruction of the human auricle remains a formidable challenge for plastic surgeons. Autologous costal cartilage grafts and alloplastic implants are technically challenging, and aesthetic and/or tactile outcomes are frequently suboptimal. Using a small animal "bioreactor", we have bioengineered full-scale ears utilizing decellularized cartilage xenograft placed within a 3D-printed external auricular scaffold that mimics the size, shape, and biomechanical properties of the native human auricle. The full-scale polylactic acid ear scaffolds were 3D-printed based upon data acquired from 3D photogrammetry of an adult ear. Ovine costal cartilage was processed either through mincing (1 mm3) or zesting (< 0.5 mm3), and then fully decellularized and sterilized. At explantation, both the minced and zested neoears maintained the size and contour complexities of the scaffold topography with steady tissue ingrowth through 6 months in vivo. A mild inflammatory infiltrate at 3 months was replaced by homogenous fibrovascular tissue ingrowth enveloping individual cartilage pieces at 6 months. All ear constructs were pliable, and the elasticity was confirmed by biomechanical analysis. Longer-term studies of the neoears with faster degrading biomaterials will be warranted for future clinical application. STATEMENT OF SIGNIFICANCE: Accurate reconstruction of the human auricle has always been a formidable challenge to plastic surgeons. In this article, we have bioengineered full-scale ears utilizing decellularized cartilage xenograft placed within a 3D-printed external auricular scaffold that mimic the size, shape, and biomechanical properties of the native human auricle. Longer-term studies of the neoears with faster degrading biomaterials will be warranted for future clinical application.

Epidemiology of congenital malformations of the external ear in Hunan Province, China, from 2016 to 2020

To describe the epidemiology of congenital malformations of the external ear (CMEE). Data were obtained from the Birth Defects Surveillance System in Hunan Province, China, 2016 to 2020. The prevalence of CMEEs is defined as the number of cases per 1000 fetuses (births and deaths at 28 weeks of gestation and beyond) (unit: ‰). Prevalence and 95% confidence intervals (CI) were calculated by the log-binomial method. Chi-square trend tests (χ2trend) were used to determine trends in prevalence by year. P < .05 was considered statistically significant. Crude odds ratios (ORs) were calculated to examine the association of sex, residence, and maternal age with CMEEs. Our study included 847,755 fetuses, and 14,459 birth defects were identified, including 1227 CMEEs (accounted for 8.49% of birth defects). The prevalences of birth defects and CMEEs were 17.06‰ (95%CI: 16.78-17.33) and 1.45‰ (95%CI: 1.37-1.53), respectively. A total of 185 microtia-anotias were identified, accounting for 15.08% of CMEEs, with a prevalence of 0.22‰ (95%CI: 0.19-0.25). And 1042 other CMEEs were identified, accounting for 84.92% of CMEEs. From 2016 to 2020, the prevalences of birth defects were 18.20‰, 18.00‰, 16.31‰, 16.03‰, and 16.47‰, respectively, showing a downward trend (χ2trend =8.45, P < .01); the prevalences of CMEEs were 1.19‰, 1.62‰, 1.80‰, 1.21‰, and 1.35‰, respectively, with no significant trend (χ2trend =0.09, P = .77). CMEEs were more common in males than females (1.60‰ vs 1.27‰, OR = 1.26, 95%CI: 1.12-1.41), in urban areas than in rural areas (1.77‰ vs 1.23‰, OR = 1.45, 95%CI: 1.29-1.62). The prevalences of CMEEs for maternal age < 20, 20-24, 25-29, 30-34, and ≥ 35 were 1.75‰, 1.27‰, 1.44‰, 1.47‰, and 1.58‰, respectively, with no significant difference (P > .05, reference: 25-29). Most CMEEs were diagnosed by clinical examinations (92.34%), and most CMEEs were diagnosed postpartum (within 7 days) (96.25%). In summary, we have presented the epidemiology of CMEEs in Hunan Province, China. CMEEs were more common in males than females, in urban areas than rural areas, whereas there was no significant difference in prevalence of CMEEs by maternal age. We inferred that CMEEs may be mainly related to genetics, and the mechanism needs to be examined in the future.

Determination of Novel, Cranium-Based Relationships for Construct Placement in Microtia Reconstruction for Hemifacial Microsomia Patients

OBJECTIVE

Determine if the ideal location of the construct in microtia reconstruction for hemifacial microsomia (HFM) can be more accurately derived from measurements on the cranium.

DESIGN

High-resolution computerized tomography (CT) images were analyzed through craniometric linear relationships.

SETTING

Our tertiary care institution from 2000 to 2021.

PATIENTS/PARTICIPANTS

Patients diagnosed with HFM and microtia, who had high-resolution craniofacial CT scans, yielding 36 patients accounting for 44 CT scans.

MAIN OUTCOME MEASURE(S)

First, the integrity of the posterior cranial vault among HFM patients was determined. If proven to be unaffected, it could be used as a reference in the placement of the construct. Second, the position of the ear in relation to the cranium was assessed in healthy age-matched controls. Third, if proven to be useful, the concordance of these cranium-based relationships could be validated among our HFM cohort.

RESULTS

The posterior cranial vault is unaffected in HFM (P > .001). Further, craniometric relationships between the tragus and the Foramen Magnum, as well as between the tragus and the posterior cranium, have been shown to be highly similar and equally precise in predicting tragus position in healthy controls (P > .001). These relationships held true across all age groups (P > .001), and importantly among HFM patients, where the mean absolute difference in predicted tragus position never surpassed 1.5 mm.

CONCLUSIONS

Relationships between the tragus and the cranium may be used as an alternative to distorted facial anatomy or surgeon's experience to assist in pre-operative planning of construct placement in microtia reconstruction for HFM patients.