A mouth is present in all animals, and comprises an opening from the outside into the oral cavity and the beginnings of the digestive tract to allow eating. This review focuses on the earliest steps in mouth formation. In the first half, we conclude that the mouth arose once during evolution. In all animals, the mouth forms from ectoderm and endoderm. A direct association of oral ectoderm and digestive endoderm is present even in triploblastic animals, and in chordates, this region is known as the extreme anterior domain (EAD). Further support for a single origin of the mouth is a conserved set of genes that form a ‘mouth gene program’ including foxA and otx2. In the second half of this review, we discuss steps involved in vertebrate mouth formation, using the frog Xenopus as a model. The vertebrate mouth derives from oral ectoderm from the anterior neural ridge, pharyngeal endoderm and cranial neural crest (NC). Vertebrates form a mouth by breaking through the body covering in a precise sequence including specification of EAD ectoderm and endoderm as well as NC, formation of a ‘pre‐mouth array,’ basement membrane dissolution, stomodeum formation, and buccopharyngeal membrane perforation. In Xenopus, the EAD is also a craniofacial organizer that guides NC, while reciprocally, the NC signals to the EAD to elicit its morphogenesis into a pre‐mouth array. Human mouth anomalies are prevalent and are affected by genetic and environmental factors, with understanding guided in part by use of animal models. WIREs Dev Biol 2017, 6:e275. doi: 10.1002/wdev.275For further resources related to this article, please visit the WIREs website.

Verrucous venous malformation is a rare vascular anomaly that presents as a deep purple skin stain and evolves into a larger scaly, keratotic lesion that can bleed and cause pain. Because of its similarity to other vascular lesions, it is often misdiagnosed and treated incorrectly. Ten patients with hand verrucous venous malformations evaluated between 1990 and 2017 were reviewed. Diagnosis was confirmed with histopathology. Six patients were initially misdiagnosed and two patients were incorrectly treated. Eight patients had excision procedures. Immunostaining for glucose transporter 1 protein was positive in all specimens that underwent staining. Most (three of four) of the patients with isolated small lesions remained disease free postoperatively, but those with larger lesions experienced recurrence or continued growth. Early recognition of verrucous venous malformation is important because nonsurgical ablative techniques are ineffective; the optimal treatment is surgery. Level of evidence: IV

Summary: 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.

Background: Demonstrating competency before independent practice is increasingly important in surgery. This study tests the hypothesis that a high-fidelity cleft lip simulator can be used to discriminate performance between training levels, demonstrating its utility for assessing procedural competence. Methods: During this prospective cohort study, participants performed a unilateral cleft lip repair on a high-fidelity simulator. Videos were blindly rated using the Objective Structured Assessment of Technical Skills (OSATS) and the Unilateral Cleft Lip Repair Competency Assessment Tool (UCLR). Digital measurement of symmetry was estimated. Influence of training level and cumulative prior experience on each score was estimated using Pearson r. Results: Participants (n = 26) ranged from postgraduate year 3 to craniofacial fellow. Training level correlated best with UCLR (R = 0.4842, P = 0.0122*) and more weakly with OSATS (R = 0.3645, P = 0.0671), whereas cumulative prior experience only weakly correlated with UCLR (R = 0.3450, P = 0.0843) and not with OSATS (R = 0.1609, P = 0.4323). UCLR subscores indicated marking the repair had little correlation with training level (R = 0.2802, P = 0.1656), whereas performance and result did (R = 0.5152, P = 0.0071*, R = 0.4226, P = 0.0315*, respectively). Correlation between symmetry measures and training level was weak.Conclusions: High-fidelity simulation paired with an appropriate procedure-specific assessment tool has the construct validity to evaluate performance for cleft lip repair. Simply being able to mark a cleft lip repair is not an accurate independent assessment method nor is symmetry of the final result.