Abstract
Background/Aim: Hemifacial microsomia (HFM) is the second most common congenital anomaly of the craniomaxillofacial region after the cleft lip and palate. This malformation is characterized by unilateral mandible and ear hypoplasia. Treatment varies and depends on different phenotypes. Severe deficiencies require multiple reconstructive surgeries to address facial asymmetries. This study aimed to review the surgical approach and evaluate the postoperative results of a case with right hemifacial microsomia and anotia. Case Report: This is the case of a 35-year-old female patient who, after multiple graft operations in the right mandible due to hemifacial microsomia, was operated for auricle reconstruction. Initially, a three-dimensional custom made Medpor (porex) was used, covered by the superficial temporal fascia. Subsequently, due to inflammation and partial exposure of this porous polyethylene implant (PPI), a temporalis muscular flap along with the deep temporal fascia were used as a salvage operation. Ten months later, the patient underwent deep plane face lift combined with open rhinoplasty. Lefort I osteotomies and transoral lip lengthening through a transection of the levator nasi septi muscle were also performed. Ear helix reconstruction was completed with a rotation scalp flap after tissue expansion. The patient had an uncomplicated postoperative course with an aesthetically acceptable result. Conclusion: As a congenital disorder, hemifacial microsomia is present at birth and successful reconstruction is of fundamental importance for the smooth integration of these individuals into society. The multiple asymmetries, the affected topographic area of the face, as well as the onset in neonatal age constitute a challenge for reconstructive surgery.
- Hemifacial microsomia
- microtia
- anotia
- auricle reconstruction
- three-dimensional Medpor
- porous polyethylene implant
Hemifacial microsomia (HFM) is the second most common congenital anomaly of the craniomaxillofacial region after the cleft lip and palate. There is a considerable variability in the extent and severity regarding the afflicted facial bones and soft tissues (1). Although the precise aetiology of this disorder is unknown, disruption of the first and second branchial arches during the first six weeks of gestation is thought to be causative (2). Therefore, these patients are characterized by an underdevelopment of the facial features arising from the first and second embryonic pharyngeal arches. The most common anatomical structures, which can be affected and present a different degree of hypoplasia, are the mandible, maxilla, ear, orbit, facial nerve, and facial soft tissues. Deficiencies that lead to obvious asymmetries and poor aesthetic or functional outcomes include mandibular hypoplasia, asymmetric malar height and projection, deficient mastoid, microphthalmia as well as microtia or anotia. Complications may occur, as these anomalies compromise the airway, affect feeding, disrupt hearing, prevent normal facial movement, and alter facial appearance (3, 4).
Many different terms have been proposed for this malformation, indicating a wide spectrum of anomalies, which have been observed and emphasized by the authors from various disciplines. In addition to HFM, this congenital disorder has also been called craniofacial microsomia (currently, it is believed that this is the most accepted medical term to mention this pathology), first and second branchial arch syndrome, oculo-auriculo-vertebral dysplasia, unilateral oto-mandibular dysostosis, lateral facial dysplasia, oculo-auriculo-vertebral spectrum, and facio-auriculo-vertebral sequence (2).
The estimated prevalence of HFM ranges from 1 in 3,500 to 1 in 5,600 live births and in some cases, it can be as rare as 1 in 26,550 live births (2, 4). The major discrepancy in the literature regarding the incidence of this congenital disorder may be due to the lack of information on terminated pregnancies and fetal deaths, as well as the inclusion or exclusion of mild or extreme cases, where a different diagnosis may be given. Although the majority of cases are sporadic and appear to have a multifactorial aetiology, cases with chromosomal abnormalities (mainly in chromosomes 5 [5p deletion], 18 [trisomy] and 22 [22q11.2 deletion]), mosaicism, as well as families with autosomal dominant and autosomal recessive inheritance have also been reported (2).
The terms microtia and anotia refer to the underdevelopment and the absence of the auricle, respectively and they are usually accompanied by a narrow, blocked or even an absent ear canal. It is estimated that they affect 1 to 5 out of every 10,000 live births worldwide (5). Microtia-anotia spectrum is present in up to 66%-99% of all hemifacial microsomia cases (6).
Treatment of HFM varies according to age, clinical manifestations, and systemic associations. Moderate phenotypes may not need to undergo any treatment from infancy through adulthood. However, severe HFM cases require multiple surgical procedures to address facial asymmetries. Reconstructive surgery is almost always necessary in these patients. The treatment aims not only to improve functionality but also to optimize facial symmetry (2, 7).
The purpose of this study was to review the surgical approach and evaluate the postoperative results of a case with right hemifacial microsomia and anotia, treated in the Greek Anticancer Institute, a tertiary referral centre. Taking into consideration the postoperative complications along with the final result, the present study aimed to demonstrate that plastic and reconstructive surgery can offer a desirable aesthetic outcome and is considered to be of paramount importance for the smooth integration of these young individuals into society.
Case Report
The present study is a case report. The patient has given consent for possible publication of her case and illustrations. No recognisable features are included in the illustrations. Details regarding personal information and identification remain absolutely anonymous and confidential.
The patient is a 35-year-old female, with a medical history of right hemifacial microsomia, presented at birth. The clinical features included an asymmetry of the face on the grounds of an underdevelopment of the right part of the mandible accompanied by a complete absence of the right external ear (anotia). The development of the left side of the face was normal. Trismus was the main clinical manifestation in this patient.
Initially, the patient underwent multiple surgical procedures for mandible reconstruction in a different Department, where bone grafts from the anterior iliac crest were used. Then, she was referred for the right auricle reconstruction. A three-dimensional (3-D) custom made Medpor (porex) was used. This is a porous polyethylene implant (PPI), which was placed in the anatomical site of the right aplastic external ear. The implant was covered with the superficial temporal fascia. A thin temporoparietal fascia flap (TPF) was raised and wrapped around the 3-D porous polyethylene implant. A full thickness skin graft covered the TPF flap and was rigidly fixed with a tie-over technique. Seven days postoperatively the surgical site developed inflammation and infection signs, as well as a partial necrosis of the skin graft. A conservative management was initially decided, including antibiotic administration and wound debridement. However, no improvement was observed and fifteen days postoperatively a wound dehiscence along with a partial exposure of the implant occurred (Figure 1).
The 35-year-old patient with the right hemifacial microsomia and right anotia (A). The left side of the patient’s face, where the development of the left ear is normal, along with a normal hearing function (B). The first surgical procedure, where a thin temporoparietal fascia flap (TPF) was raised and wrapped around the 3-D porous polyethylene implant (C and D). A full thickness skin graft covered the TPF flap and was rigidly fixed with a tie-over technique (E and F). Surgical site infection developed seven days postoperatively (G). Partial skin graft necrosis, wound dehiscence, along with partial exposure of the implant (H).
The patient underwent a second surgical procedure, where a temporalis muscular flap combined with the deep temporal fascia were used as a salvage operation, in order to cover the exposed implant. A full thickness skin graft was also used for the muscular flap coverage. The postoperative course was uncomplicated and the patient was discharged after six days (Figure 2). A partial reconstruction of the external ear had already been achieved with these two operations, while the ear helix had also to be reconstructed.
The second surgical procedure, where a temporalis muscular flap along with the deep temporal fascia were raised (A) and used in order to cover the exposed implant, as a salvage operation (B). A full thickness skin graft was also used for the muscular flap coverage (C). The postoperative result one week (D), two weeks (E), and six months after surgery (F).
Ten months later, the patient underwent the third operation in order to achieve a bilateral facial symmetry and improve her clinical characteristics. A deep plane face lift was performed, in combination with an open rhinoplasty. Lefort I osteotomies and a transoral lip lengthening through a transection of the levator septi nasi muscle were also performed (Figure 3).
The right and left side of the patient’s face before the third surgical procedure (A and B). The patient’s nose after the open rhinoplasty (C and D). The patient before (E) and after the deep plan face lift, open rhinoplasty, Lefort I osteotomies, and transection of the levator septi nasi muscle (F). The right ear after the reconstruction with the 3-D porous polyethylene implant (G), where a similarity to the normal left ear has been achieved (H).
Fifteen months later, a tissue expander was inserted in the right temporal area (fourth operation), aiming at the ear helix reconstruction. Although an adequate skin expansion was achieved, the tissue expander had to be removed a month after its insertion, due to partial exposure. Therefore, the patient underwent her fifth operation, where the tissue expander was removed. The expanded tissue was folded around the upper part of the 3-D Medpor, adopting a shape and protrusion similar to the ear helix. The hospitalisation was uncomplicated and the patient was discharged the sixth day. The auricular reconstruction of this patient was completed, having achieved a satisfying and aesthetically acceptable final outcome (Figure 4).
The skin expansion and the partial exposure of the tissue expander (A). The removal of the tissue expander and the folding of the expanded tissue around the upper part of the 3-D Medpor, adopting a shape and protrusion similar to the ear helix (B and C). The final postoperative result after the completion of the auricular reconstruction, having achieved an aesthetically acceptable outcome (D).
Discussion
The present study aimed to review the surgical approach and evaluate the results of a case with right hemifacial microsomia and right anotia. Hemifacial microsomia is characterized by unilateral hypoplasia of the mandible and ear, including a malformed condyle, hypoplastic coronoid process, shortened mandibular ramus, small glenoid fossa and preauricular tags. Mandible hypoplasia is a typical finding in HFM and appears in approximately 73% to 91% of HFM cases. Mandibular hypoplasia correlates with an increased risk of obstructive sleep apnoea (OSA), due to the obstruction at the level of the tongue base. The prevalence of OSA in HFM is estimated between 7% and 24%. More severe phenotypes of HFM or bilateral HFM are expected to be at the highest risk of OSA. Feeding difficulties can also be present in 42% to 83% of cases with HFM. Regarding salivary glands, hypoplasia/aplasia of the parotid gland is detected in 84% of HFM patients, with an additional hypoplasia of the submandibular gland in 26% of these cases. Dental hypoplasia or hypodontia is present in 8% to 25% of HFM cases (8).
Asymmetries in orbit size and position (orbital dystopia) are usually observed in 4% to 43% of the HFM cases, but rarely require surgical treatment. Eyelid colobomata and epibulbar dermoids are common findings in HFM, with a prevalence of 4-40% and 7-69%, respectively. Other HFM-associated anomalies include lacrimal gland or duct anomalies, microphthalmia, anophthalmia, lipodermoids, iris colobomata, blepharoptosis, optic nerve anomalies, astigmatism, strabismus, and amblyopia. Bilateral facial asymmetries are more likely to be accompanied by ocular anomalies than unilateral HFM. In 10% to 55% of HFM cases facial nerve palsy is detected, while soft-tissue deficiency is expected to be observed in up to 82% of such cases. Approximately 55% of HFM patients also develop extracranial anomalies including skeletal/vertebral (28%), cardiac (21%), central nervous system (11%), renal (11%), gastrointestinal (9%), and respiratory (2%) defects (2, 8). Regarding the case of the present study, the clinical examination and medical history revealed that this patient has no ocular asymmetries, unilateral facial palsy, obstructive sleep apnoea or any other extracranial malformations.
Three possible pathogenic models of HFM have been described: a vascular abnormality and haemorrhage in the craniofacial region, a Meckel’s cartilage damage, and an abnormal development of the cranial neural crest cells. These three models are considered to be interrelated and none of them is completely concordant with all the variable and distinct manifestations of HFM (7, 9). However, the most plausible hypothesis regarding the HFM pathogenesis is the vascular abnormality and haemorrhage theory. It has been proposed that the pathogenetic makeup of hemifacial microsomia is based on the formation of an embryonic hematoma arising from the anastomosis that precedes the stapedial artery formation. Therefore, the heterogeneity, variation, and severity of the HFM clinical findings are considered to be a direct consequence of the size and amount of hematoma collection and expansion. Small hematomas cause less damage than their larger counterparts, which hinder branchial arch growth (2).
Environmental causes of HFM have also been reported. Various risk factors associated with pregnancy have been reported, such as multiple gestations, vaginal bleeding during the second quarter, vasoactive medications, pre-existing or gestational diabetes, as well as the use of assisted reproductive technology by the mother (2).
Other external environmental factors (e.g., retinoic acid, triazene, thalidomide and vasoactive medications), maternal intrinsic factors (e.g., maternal diabetes), as well as genetic factors (e.g., the recently reported mutations in MYT1, PLCD3 and OTX2) may lead to HFM through more than one of these pathogenic processes (9). In the present case, there are no known hereditary predisposition or environmental factors that may have contributed to the manifestation of this disorder.
Microtia is defined as a developmental malformation of the external ear, characterized by a small, abnormally shaped auricle. Aural atresia is found in 75% of microtia cases. The prevalence of microtia varies and has been reported to range between 0.8-17.4/10,000 in different populations. The precise mechanism of microtia development is a subject of ongoing research. The microtia phenotype appears in a wide spectrum of disorders, the most common of which include hemifacial/craniofacial microsomia, Goldenhar and Treacher Collins syndrome. Multiple other syndromes or genetic causes have been identified to be associated with this developmental malformation in less than 50% of cases (10). Microtia can present unilaterally or bilaterally. The unilateral subtype is much more common, occurring in 79-93% of cases. The right ear is more frequently affected in a percentage of approximately 60% of unilateral microtia cases. Microtia can be associated with stenosis (narrowing) or atresia (absence or closing) of the ear canal in 55-93% of patients. The extreme scenario where there is neither external ear nor auditory canal is defined as anotia or microtia grade IV. The anotia prevalence has been estimated to vary between 5 and 22% of all microtia cases (11). In cases of anotia as the one in the present study, where the auditory canal is absent, the surgical approach is aiming only at the auricular reconstruction for aesthetical purposes, while the hearing function cannot be restored.
Hemifacial microsomia treatment includes repair of bony asymmetries as well as auricular anomalies and soft tissue defects. Surgical intervention should be individualized and always oriented to each patient’s deficits (12). The reconstructive principles and corrective techniques aiming at microtia-anotia repair are less reliable in this patient population due to the ipsilateral microsomia and facial asymmetries, making auricle reconstruction a real challenge. Several parameters should be taken into consideration. Relying on contralateral measurements relative to the midline usually leads to a position of the auricular construct too posteriorly. Additionally, the location of the remnant earlobe and vestige skin is often too anteriorly or inferiorly. As a result, they cannot indicate the ideal location of the auricle. This parameter also makes the earlobe reconstruction technically more challenging. When a more severe facial asymmetry and hypoplasia are present, the creation of a construct identical in size to the contralateral side may result in a disproportionately large ear. Classical coverage techniques can also be proven unsuitable, mainly due to the underdeveloped temporoparietal fascia and underlying temporal muscle, the taut and thin retroauricular skin, the low hairline that causes a lack of non-hair-bearing skin and the unreliable arterial anatomy. The combination of these factors along with a depressed temporal bone may also impede a successful ear elevation with an appropriate projection and cranioauricular angle (6).
Two major surgical techniques for microtia and anotia have been described: autologous reconstruction with costal cartilage and synthetic reconstruction based on a porous polyethylene implant (PPI). A considerable debate is currently ongoing regarding the most appropriate method for various clinical settings in which to best apply these different techniques. Nonetheless, both surgical methods aim to create a reliable construct for the novel auricular framework, which is then covered with native tissue, such as fascia, skin or both (5).
An expanded two-flap method has also been described for auricular reconstruction. This surgical approach includes three stages. In the first stage, a kidney-shaped tissue expander is used for the expansion of the retroauricular skin. The second stage consists of the costal cartilage harvesting and the framework fabrication. The anterior surface of the framework is enveloped with the already expanded skin flap. Then, a retroauricular fascial flap and a full-thickness skin graft cover the posterior surface and the helical rim of the framework. In the third stage, the tragus reconstruction, lobule formation, and concha excavation are performed (13).
There are several cases, where a combination of both autologous and non-autologous techniques has to be adopted for the external ear reconstruction (14). In the present case both methods have been performed. A 3-D custom made PPI was inserted and initially covered with the TPF and then with a temporalis muscular flap. For the ear helix reconstruction, a tissue expander was used and then the appropriately expanded colour-matched skin was folded around the upper part of the 3-D porex. As a result, non-autologous methods in combination with autologous tissues have played a significant role in order to achieve the final auricle reconstruction. Adopting this surgical approach, an auricle with excellent definition and projection has been obtained with a minimal complication rate and a long-term viability.
Complications regarding each surgical technique should also be taken into consideration. Autologous cartilage reconstruction can most commonly be complicated with cartilage exposure and surgical site infection. Topical wound care and antibiotic administration are often an effective course of action. In some cases, the management may require a local flap for coverage. Other complications may also appear including a malposition, a cartilage resorption, a low-lying hair, as well as framework disarticulations and delayed framework fractures. On the other hand, reconstruction based on alloplastic implant placement has shown a dramatic reduction of complication rates in recent years. Comparing modern techniques with initial attempts, considerable reductions in implant exposure (from 44% to <5%) and implant fracture (from 28% to <9%) have been reported (10, 15).
Unsuccessful reconstruction can happen and may be rescued by using an auricular prosthesis. Therefore, prosthetic treatment should always be offered as an option to these patients. This approach was quite common a few decades ago. However, with the advancement of surgical techniques in auricular reconstruction, this method is now selected much less frequently. Nonetheless, it is still performed to some degree, as each patients’ estimation and objective view of the result may vary or differ. Auricular prostheses can also be selected as a temporary measure in paediatric patients and adolescents with microtia, while waiting for reconstructive surgery. They can also be used for testing reasons before implant surgery. In both situations, the prosthesis is fixed on top of the auricular remnant by the use of medical adhesives. Usually, the smaller the remnant is, the more feasible the fabrication of a cosmetically appealing prosthesis is. On the other hand, in large remnants, difficulties may arise regarding the integration of the remnant underneath the prosthesis. It is also worth mentioning, that patients have the right to choose prosthetic rehabilitation as a definitive treatment. Many patients with microtia prefer implant-retained auricular prosthesis without any previous reconstructive surgery, as they wish to avoid the inconvenience, surgical risk and unpredictability of autologous or implant-based surgical procedures for auricular reconstruction (16).
Conclusion
Although HFM is one of the most common craniofacial anomalies, the surgical treatment remains both challenging and controversial. Surgical techniques continue to evolve with better results. However, patients with hemifacial microsomia accompanied by anotia have a combination of complex anatomical abnormalities, that often preclude favourable aesthetic outcomes following reconstructive surgery.
The present case report demonstrates that a considerable number of surgical approaches is required in order to achieve a desirable and aesthetically acceptable result. Postoperative complications may occur and depend on the selected surgical procedures.
Acknowledgements
The Authors would like to thank the patient for accepting to participate in this study.
Footnotes
Authors’ Contributions
Aikaterini Bini is the primary author, responsible for manuscript preparation, drafting and editing. Aikaterini Bini is also the corresponding author. Aikaterini Bini and Spyridon Stavrianos contributed to the protocol preparation and guidance of the study. Spyridon Stavrianos is the surgeon of this patient, who collected and provided all the information and illustrations of this case. Aikaterini Bini and Spyridoula Derka reviewed the relevant literature. Spyridoula Derka helped also in editing the manuscript. Spyridoula Derka and Spyridon Stavrianos reviewed the manuscript. All Authors read and approved the final manuscript.
Funding
The Authors did not receive financial support from any organization for the submitted work.
Conflicts of Interest
The Authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
- Received April 11, 2024.
- Revision received June 2, 2024.
- Accepted June 4, 2024.
- Copyright © 2024 The Author(s). Published by the International Institute of Anticancer Research.
This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY-NC-ND) 4.0 international license (https://creativecommons.org/licenses/by-nc-nd/4.0).
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