Anatomical Basis for Apparent Subepithelial Cleft Lip: A Histological and Ultrasonographic Survey of the Orbicularis Oris Muscle

Sonographic Analysis of the Upper Labial Orbicularis Oris and Its Clinical Implications

BACKGROUND

Purse string lips, which include the vertical wrinkles over the lips, are frequently observed in aged individuals. Botulinum toxin and fillers are routinely injected into these areas to remove the wrinkles; however, the anatomy of the orbicularis oris muscle (OOr) near the vermilion border area has not been well defined.

OBJECTIVES

The aim of this study was therefore to identify any morphological differences of the upper OOr via sonographic imaging.

METHODS

The upper lip muscles as observed utilizing an ultrasound device were divided into 2 muscles (pars peripheralis and pars marginalis) that were subsequently divided into a further 2 types (Type I and Type II) associated with the development of the pars marginalis. Type II was further divided into Type IIa and Type IIb depending on whether the muscle fibers were well developed and connected.

RESULTS

On the midline of the lip, Type I, in which the pars marginalis was rarely observed and only appeared in traces, was observed in 20.0% of the volunteers. Type IIa, in which the pars marginalis was well-developed and appeared continuous, was observed in 42.9% of the volunteers. Type IIb, in which the pars marginalis was observed but appeared discontinuous, was observed in 37.1% of the volunteers.

CONCLUSIONS

The shapes of the upper pars marginalis of the OOr varied markedly between volunteers. Type classification of the OOr based on its shape and the lip appearance serves as a reliable source of reference information to be utilized when injecting botulinum toxin into the upper lip.

"Three Subunit" Classification of Lesser-Form Cleft Lip and Muscle Analysis and Reconstruction of These Subunits Based on the Microanatomic Structures of Muscles in the Normal Upper Lip

BACKGROUND

The main phenotypic features of lesser-form cleft lip include nasal, philtrum, and vermilion deformities. The manifestations of lesser-form cleft lip vary greatly, and it is difficult to rebuild these subunits during the operation.

METHODS

"Three subunits" classification of lesser-form cleft lip was identified as nasal deformity (N), philtrum deformity (P), or vermilion deformity (V); and slight deformity (0) or obvious deformity (1). A total of 200 patients with lesser-form cleft lip were classified into one of the following 8 types: N1P1V1, N1P1V0, N0P1V1, N1P0V1, N0P0V1, N1P0V0, N0P1V0, or N0P0V0. Then the authors discussed the deformities of the lesser-form cleft lip and the reconstruction of the muscles in these subunits based on the microanatomic structure of the nasolabial muscle.

RESULTS

This retrospective review included 200 patients with a lesser-form cleft lip, who were seen at our center from 2015 to 2017. There were 149 (74.5%) N1P1V1, 11 (5.5%) N1P1V0, 13 (6.5%) N0P1V1, 4 (2.0%) N1P0V1, 8 (4.0%) N0P0V1, 10 (5.0%) N1P0V0, 1 (0.5%) N0P1V0, and 4 (2%) N0P0V0 clefts. The various deformities of nasal floor, philtrum ridge, and vermilion may suggest that the muscle bundles in these subunits are abnormal and the operation should be performed to simulate the running directions and tension lines of these local muscles.

CONCLUSIONS

The microanatomic structure and the tension lines of the nasolabial muscles can provide new perspectives for better understanding and repairing the lesser-form cleft lip in subunits.

Is PRP Effective in Reducing the Scar Width of Primary Cleft Lip Repair? A Randomized Controlled Clinical Study

Objective:

To evaluate and analyze the effect of platelet-rich plasma (PRP) injection on the scar formed after unilateral complete cleft lip scar repair using a modified Millard technique.

Hypothesis:

An unavoidable cheiloplasty scar is a result of the wound healing process that not only influences patient self-esteem for life but also affects muscle function.

Design:

Blind, randomized, controlled clinical trial.

Patients:

From December 2016 to February 2018, 24 patients with unilateral complete cleft lip undergoing primary cheiloplasties were equally assigned to study and control groups.

Intervention:

All patients were treated by modified Millard cheiloplasty. In the study group, PRP was injected into the muscle and skin layers immediately after wound closure, while the control group patients were treated with no PRP injection.

Outcomes Measures:

Scar width was assessed after 6 months through the muscle using ultrasonography and at the skin surface via photographs.

Results:

Scar width showed a significant improvement in the study group.

Conclusions:

Injection of autologous PRP provides effective improvement of cutaneous and muscular wound healing and decreases scar tissue formation.

A New Paradigm in Cleft Lip Procedural Excellence: Creation and Preliminary Digital Validation of a Lifelike Simulator

Simulation is becoming an increasingly important tool for hands-on surgical education in a no-risk environment. Cleft lip repair is a common procedure where precise technique is needed to achieve optimal outcome, making it an ideal candidate for simulation. A digital simulated patient with a typical unilateral complete cleft lip and alveolus was constructed using existing three-dimensional imaging studies. Key surface and internal anatomical elements were characterized in detail. A prototype high-fidelity simulator was constructed with silicone and synthetic polymers over a supportive scaffold, piloted by three surgeons using multiple techniques, and digitally compared to real patients. All surgeons completed key steps of a cleft lip repair on the simulator and found it approximated the haptics and anatomy of a cleft lip. Surface change and anthropometric movements accomplished on the simulator were similar for all three surgeons. In digital comparison to analogous real patient data, the simulator anthropometric movements and topographic change were similar to real nasolabial movement. A high-fidelity cleft lip simulator provides "on-demand" opportunity to realistically practice all steps of a cleft lip repair, with implications for overcoming volume-outcome relationship challenges of diminishing operative experience for resident surgeons.

Quantitative assessment of healthy and reconstructed cleft lip using ultrasonography

Purpose:

This study is conducted to investigate the feasibility of echographic imaging of tissue thickness of healthy and reconstructed cleft lip.

Design:

Prospective study.

Materials and Methods:

The study was conducted in SDM Craniofacial Unit, Dharwad and was approved by Local Institutional Review Board. A total of 30 patients, age group ranging from 4 to 25 years, of which 15 postoperative unilateral cleft lip constituted the test group. The remaining 15 with no cleft deformities, no gross facial asymmetry, constituted the control group. The thickness of the mucosa, submucosa, muscle and full thickness of the upper lip were measured with the transversal images using ultrasonography at midpoint of philtrum, right and left side philtral ridges and vermillion border, at 1, 3, 6 months interval.

Results:

There was an increase in muscle thickness at the vermillion border (mean = 6.9 mm) and philtral ridge (5.9 mm). Equal muscle thickness were found between the normal and test group at 6 months follow-up in a relaxed position, which was statistically significant (P = 0.0404).

Conclusion:

Quantitative assessment of thickness and echo levels of various lip tissues are done with proper echographic calibration. Diagnostic potentials of this method for noninvasive evaluation of cleft lip reconstructions were achieved by this study.

The philtrum in cleft lip: review of anatomy and techniques for construction

The philtrum is imperfectly formed in both unilateral and bilateral cleft lip. Surgical construction of this exquisite feature in the upper lip is challenging and often takes a back seat to construction of Cupid's bow and the nose. However, the philtrum is one of the defining features of a normal lip. The purpose of this review is to compile information on philtral anatomy and techniques for construction to guide the reader on his or her own quest to optimize cleft lip repair. In this article, we review the normal anatomy of the philtral dimple and ridges, with particular attention to pars peripheralis configuration. We also review methods for philtral construction during primary labial repair and secondary labial revision. For unilateral cleft lip, eversion of orbicularis oris muscle is necessary to build a philtral ridge. For bilateral cleft lip, emphasis is on proper design of the philtral flap and efforts to simulate a dimple and ridges. For secondary philtral correction, techniques include complete labial revision with various types of muscular re-repair and autologous philtral ridge augmentation. Objective methods are needed to document the efficacy of the many techniques for philtral construction and reconstruction.

[Comparative ultrasonographic and histomorphologic examination of the lips]

BACKGROUND

High-resolution ultrasonography of the lips offers the opportunity to investigate the orbicularis oris muscle (OOM) and evaluate its morphology and function.

OBJECTIVES

The goals of this paper are verification of the lip structures visible on ultrasound images by using histological section preparations and recommendation of uniform standards for sonographic examinations of the lips.

MATERIALS AND METHODS

The lips of 78 healthy volunteers (age 4-77 years) where scanned with a Hitachi Hi Vision Avius ultrasound device equipped with a linear transducer (L75, variable frequency range 5.0-18.0 MHz). Systematic B-mode examination was performed at five defined points, and the lips where also scanned dynamically in multiple directions. The ultrasonography findings were verified by using histologic samples from five male body donors (age 72-83 years).

RESULTS

All parts of the OOM could be well distinguished from one another both histologically and ultrasonographically. Sonographically visible lip structures could be verified histologically. Labial glands and blood vessels of the mucosa could be identified with both methods.

CONCLUSION

Ultrasonography allows identification of lip structures and all parts of the OOM. Scars, injuries and atrophy of the lip musculature are well detectable. Functional examinations can visualize muscular dysfunctions and may support the diagnosis of dystonic or hypotonic functional deficits. The following parameters are mandatory for a standardized examination of the lips: sagittal and transverse images of upper and lower lips; use of anatomical "landmarks"; functional diagnostics in tensed and relaxed conditions.

Classification, epidemiology, and genetics of orofacial clefts

Orofacial clefts (OFCs) include a broad range of facial conditions that differ in cause and disease burden. In the published literature, there is substantial ambiguity in both terminology and classification of OFCs. This article discusses the terminology and classification of OFCs and the epidemiology of OFCs. Demographic, environmental, and genetic risk factors for OFCs are described, including suggestions for family counseling. This article enables clinicians to counsel families regarding the occurrence and recurrence of OFCs. Although much of the information is detailed, it is intended to be accessible to all health professionals for use in their clinical practices.

Cleft lip - a comprehensive review

Orofacial clefts comprise a range of congenital deformities and are the most common head and neck congenital malformation. Clefting has significant psychological and socio- economic effects on patient quality of life and require a multidisciplinary team approach for management. The complex interplay between genetic and environmental factors play a significant role in the incidence and cause of clefting. In this review, the embryology, classification, epidemiology, and etiology of cleft lip are discussed. The primary goals of surgical repair are to restore normal function, speech development, and facial esthetics. Different techniques are employed based on surgeon expertise and the unique patient presentations. Pre-surgical orthopedics are frequently employed prior to definitive repair to improve outcomes. Long term follow up and quality of life studies are discussed.

Genetics of cleft lip and cleft palate

Orofacial clefts are common birth defects and can occur as isolated, nonsyndromic events or as part of Mendelian syndromes. There is substantial phenotypic diversity in individuals with these birth defects and their family members: from subclinical phenotypes to associated syndromic features that is mirrored by the many genes that contribute to the etiology of these disorders. Identification of these genes and loci has been the result of decades of research using multiple genetic approaches. Significant progress has been made recently due to advances in sequencing and genotyping technologies, primarily through the use of whole exome sequencing and genome-wide association studies. Future progress will hinge on identifying functional variants, investigation of pathway and other interactions, and inclusion of phenotypic and ethnic diversity in studies.

Search for genetic modifiers of IRF6 and genotype-phenotype correlations in Van der Woude and popliteal pterygium syndromes

Van der Woude syndrome is the most common form of syndromic orofacial clefting, accounting for 1-2% of all patients with cleft lip and/or cleft palate. Van der Woude and popliteal pterygium syndromes are caused by mutations in IRF6, but phenotypic variability within and among families with either syndrome suggests that other genetic factors contribute to the phenotypes. The aim of this study was to identify common variants acting as genetic modifiers of IRF6 as well as genotype-phenotype correlations based on mutation type and location. We identified an association between mutations in the DNA-binding domain of IRF6 and limb defects (including pterygia). Although we did not detect formally significant associations with the genes tested, borderline associations suggest several genes that could modify the VWS phenotype, including FOXE1, TGFB3, and TFAP2A. Some of these genes are hypothesized to be part of the IRF6 gene regulatory network and may suggest additional genes for future study when larger sample sizes are also available. We also show that families with the Van de Woude phenotype but in whom no mutations have been identified have a lower frequency of cleft lip, suggesting there may be locus and/or mutation class differences in Van de Woude syndrome.

Cell-autonomous and non-cell-autonomous roles for IRF6 during development of the tongue

Interferon regulatory factor 6 (IRF6) encodes a highly conserved helix-turn-helix DNA binding protein and is a member of the interferon regulatory family of DNA transcription factors. Mutations in IRF6 lead to isolated and syndromic forms of cleft lip and palate, most notably Van der Woude syndrome (VWS) and Popliteal Ptyerigium Syndrome (PPS). Mice lacking both copies of Irf6 have severe limb, skin, palatal and esophageal abnormalities, due to significantly altered and delayed epithelial development. However, a recent report showed that MCS9.7, an enhancer near Irf6, is active in the tongue, suggesting that Irf6 may also be expressed in the tongue. Indeed, we detected Irf6 staining in the mesoderm-derived muscle during development of the tongue. Dual labeling experiments demonstrated that Irf6 was expressed only in the Myf5+ cell lineage, which originates from the segmental paraxial mesoderm and gives rise to the muscles of the tongue. Fate mapping of the segmental paraxial mesoderm cells revealed a cell-autonomous Irf6 function with reduced and poorly organized Myf5+ cell lineage in the tongue. Molecular analyses showed that the Irf6−/− embryos had aberrant cytoskeletal formation of the segmental paraxial mesoderm in the tongue. Fate mapping of the cranial neural crest cells revealed non-cell-autonomous Irf6 function with the loss of the inter-molar eminence. Loss of Irf6 function altered Bmp2, Bmp4, Shh, and Fgf10 signaling suggesting that these genes are involved in Irf6 signaling. Based on these data, Irf6 plays important cell-autonomous and non-cell-autonomous roles in muscular differentiation and cytoskeletal formation in the tongue.

The evolution of human genetic studies of cleft lip and cleft palate

Orofacial clefts (OFCs)--primarily cleft lip and cleft palate--are among the most common birth defects in all populations worldwide, and have notable population, ethnicity, and gender differences in birth prevalence. Interest in these birth defects goes back centuries, as does formal scientific interest; scientists often used OFCs as examples or evidence during paradigm shifts in human genetics, and have also used virtually every new method of human genetic analysis to deepen our understanding of OFC. This review traces the evolution of human genetic investigations of OFC, highlights the specific insights gained about OFC through the years, and culminates in a review of recent key OFC genetic findings resulting from the powerful tools of the genomics era. Notably, OFC represents a major success for genome-wide approaches, and the field is poised for further breakthroughs in the near future.

Nasolabial fold discontinuity during speech as a possible extended cleft phenotype

Objective : This exploratory research sought to extend the cleft phenotype by identifying movement-related soft tissue appearance changes in the midfacial region in individuals with cleft lip/palate or those with genetic susceptibility to cleft lip/palate (unaffected relatives). The cleft phenotype (clinically identified orofacial cleft or subclinical orbicularis oris defect) was hypothesized to be associated with movement related appearance changes in the midfacial region, e.g., with furrowing and dimpling during speech. Design : Changes in the appearance of skin in the midfacial region, including a newly identified phenotypic feature, nasolabial fold (NLF) discontinuity, were described and compared across groups. Participants : Individuals with cleft lip (n  =  42), unaffected relatives of persons with a cleft (n  =  57) and healthy controls (n  =  41) were compared. Results : Frequencies of NLF discontinuity differed across cleft, relative, and control groups. NLF discontinuities were observed more frequently in individuals with a cleft phenotype (overt cleft or previously identified orbicularis oris muscle defect) than in those with no underlying muscular defect (Fisher exact test, P  =  .014). Conclusion : Results suggest that the appearance of facial soft tissue during movement of the midface is moderated at least in part by underlying cleft risk factors, indicating certain facial movements as candidate physical markers for extension of the cleft phenotype.

Cleft lip and palate: understanding genetic and environmental influences

Clefts of the lip and/or palate (CLP) are common birth defects of complex aetiology. CLP can occur in isolation or as part of a broad range of chromosomal, Mendelian or teratogenic syndromes. Although there has been marked progress in identifying genetic and environmental triggers for syndromic CLP, the aetiology of the more common non-syndromic (isolated) forms remains poorly characterized. Recently, using a combination of epidemiology, careful phenotyping, genome-wide association studies and analysis of animal models, several distinct genetic and environmental risk factors have been identified and confirmed for non-syndromic CLP. These findings have advanced our understanding of developmental biology and created new opportunities for clinical translational research.

Revisiting the recurrence risk of nonsyndromic cleft lip with or without cleft palate

Sub-epithelial defects (i.e., discontinuities) of the superior orbicularis oris (OO) muscle appear to be a part of the phenotypic spectrum of cleft lip with or without cleft palate (CL ± P). Analysis of the OO phenotype as a clinical tool is hypothesized to improve familial recurrence risk estimates of CL ± P. Study subjects (n = 3,912) were drawn from 835 families. Occurrences of CL ± P were compared in families with and without members with an OO defect. Empiric recurrence risks were calculated for CL ± P and OO defects among first-degree relatives (FDRs). Risks were compared to published data and/or to other outcomes of this study using chi-square or Fisher's exact tests. In our cohort, the occurrence of CL ± P was significantly increased in families with OO defects versus those without (P < 0.01, OR = 1.74). The total FDR recurrence of isolated OO defects in this cohort is 16.4%; the sibling recurrence is 17.2%. The chance for one or more FDRs of a CL ± P proband to have an OO defect is 11.4%; or 14.7% for a sibling. Conversely, the chance for any FDR of an individual with an OO defect to have CL ± P is 7.3%; or for a sibling, 3.3%; similar to published recurrence risk estimates of nonsyndromic (NS) CL ± P. This study supports sub-epithelial OO muscle defects as being part of the CL ± P spectrum and suggests a modification to recurrence risk estimates of CL ± P by utilizing OO defect information.

Folic acid and orofacial clefts: a review of the evidence

Orofacial clefts are common and burdensome birth defects with a complex genetic and environmental etiology. The contribution of nutritional factors and supplements to the etiology of orofacial clefts has long been theorized and studied. Multiple studies have evaluated the role of folic acid in the occurrence and recurrence of orofacial clefts, using observational and non-randomized interventional designs. While preventive effects of folic acid on orofacial clefts are commonly reported, the evidence remains generally inconsistent. This paper reviews the findings of the main studies of the effects of folic acid on orofacial clefts, summarizes study limitations, and discusses research needs with a focus on studying the effects of high dosage folic acid on the recurrence of oral clefts using a randomized clinical trial design. The role of folic acid in the prevention of neural tube defects is also briefly summarized and discussed as a reference model for orofacial clefts.

Mutations in BMP4 are associated with subepithelial, microform, and overt cleft lip

Cleft lip with or without cleft palate (CL/P) is a complex trait with evidence that the clinical spectrum includes both microform and subepithelial lip defects. We identified missense and nonsense mutations in the BMP4 gene in 1 of 30 cases of microform clefts, 2 of 87 cases with subepithelial defects in the orbicularis oris muscle (OOM), 5 of 968 cases of overt CL/P, and 0 of 529 controls. These results provide confirmation that microforms and subepithelial OOM defects are part of the spectrum of CL/P and should be considered during clinical evaluation of families with clefts. Furthermore, we suggest a role for BMP4 in wound healing.