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Making ENT Easy With No-Cost Own Hand Models: Internal Auditory Canal / Internal Acoustic Meatus (IAM)
*Corresponding author: Vijayagovindarajan Deenadayalan, Department of Otorhinolaryngology, Government Vellore Medical College and Hospital, Vellore, 632009, Tamil Nadu, India. vgovindraj@yahoo.com
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Received: ,
Accepted: ,
How to cite this article: Deenadayalan V. Making ENT Easy With No-Cost Own Hand Models: Internal Auditory Canal / Internal Acoustic Meatus (IAM). Ann Otol Neurotol. 2026;7:e001. doi: 10.25259/AONO_20_2025
Abstract
Objectives:
Understanding the anatomy of the Internal Auditory Canal (IAC) is challenging for early learners. Conventional teaching methods— cadaveric dissection, textbook diagrams, computed tomography/magnetic resonance imaging (CT/MRI), and commercial models—may be costly or unavailable. A simple, reproducible, no-cost hand model can immediately simplify this complex anatomy. To demonstrate an accessible, no-cost technique using one’s own hands and a small folded white paper strip to teach the anatomical layout of the IAC.
Material and Methods:
A folded paper strip represents Bill’s bar and the falciform crest. The left hand represents the arrangement of the facial, cochlear, superior vestibular, inferior vestibular, and singular nerves. The right hand forms an oval ring representing the IAC opening. The model requires only hands, a small white paper strip, and optional colour markings.
Results:
Students, trainees, practitioners, and patients showed improved understanding, confidence, and recall. The model significantly improved explanations of vestibular schwannoma during counselling. Many learners were able to replicate the model instantly, demonstrating its educational impact.
Conclusion:
This no-cost, instantly reproducible hand model makes IAC anatomy easy to visualize, remember, and teach. It opens possibilities for creating similar no-cost models across ENT and medical education.
Keywords
Anatomy education
Acoustic neuroma
Cochlear nerve
ear
nose
throat (ENT) anatomy
Facial nerve
Hand model
IAC
Internal acoustic meatus
No-cost teaching model
Vestibular nerves
INTRODUCTION
The Internal Auditory Canal (IAC) contains the facial nerve, cochlear nerve, superior vestibular nerve, inferior vestibular nerve, and the singular nerve in a narrow bony canal. Learners often struggle to visualize their relative arrangement without cadaveric material or expensive 3-D models.
With an aim to “Make ear, nose, throat (ENT) Easy,” the author developed a completely no-cost hand model using one’s own hands and a small folded paper strip. This model rapidly clarifies the IAC quadrants, Bill’s bar, the falciform crest, and the relative positions of the nerves.
This method is based on the author’s philosophy
“What your eyes couldn’t see, your brain couldn’t tell…What your hands could teach, your mind could easily tell.”
This tactile approach empowers learners to understand anatomy anywhere—in clinics, wards, classrooms, or at home. Over years of teaching, this approach inspired the development of similar no-cost hand models for other ENT structures, including the larynx, pharynx, nose, external ear, middle ear and inner ear.[1-4]
MATERIAL AND METHODS
Left hand as nerve model
The left hand is arranged to represent the five nerves, with each finger corresponding to a specific nerve: the index finger represents the facial nerve, the thumb represents the cochlear nerve, the middle finger represents the superior vestibular nerve, the ring finger represents the inferior vestibular nerve, and the little finger represents the singular nerve.Optional colour markings/dots may be placed on the fingertips for clarity.
Paper strip to represent Bill’s bar and falciform crest
A white paper strip (4 × 1 cm) is folded as follows:
One central fold → Bill’s bar (vertical ridge), two outward folds → Falciform crest (horizontal ridges). This will be placed to divide the IAC into superior and inferior divisions. And the superior portion is divided into anterior and posterior divisions.
Placing the paper between fingers
The folded strip is inserted between the fingers to create: Anterior–posterior division(Bill’s Bar-between the index and middle finger). Superior–inferior division(Falciform crest-between index and thumb finger, middle and ring finger. This produces the quadrant structure of the IAC.
Right hand as the canal ring
The right thumb and index finger, along with the other three fingers, form an oval ring representing the bony opening of the IAC. This ring is placed over the left-hand model to create the complete medial view of the IAC [Figure 1].
- Step-by-step construction of the no-cost own hand model of the internal auditory canal (IAC). (a-t): Right-side IAC showing the arrangement of FN, SVN, CN, IVN, and SN. Black circles denote the internal auditory canal outline for visual clarity. IVN: Inferior vestibular nerve. FN: Facial nerve, CN: Cochlear nerve, SVN: Superior vestibular nerve, SN: Singular nerve.
Demonstrating pathology
A small piece of material (cotton/paper) is placed around the Inferior Vestibular Nerve.
This helps patients visualize:
Tumour origin,nerve compression and consequences of disease, reason for investigations, symptoms related to nerve involvement.
Teaching integration
This method is used in:
Classroom teaching, bedside rounds, OPD counselling, emergency teaching , examination/viva practice , workshops and seminars. It requires no equipment and no cost, enabling anatomy to be taught literally “with our own hands [Figures 2 and 3].”
- (a-c): Right-side internal auditory canal (IAC) showing the arrangement of FN, SVN, CN, IVN, and SN. (d and e): Left-side IAC hand model arrangement of the five nerves. (f): Right side vestibular schwannoma demonstrated with a cloth around IVN. Black circles denote the internal auditory canal outline for visual clarity. IVN: Inferior vestibular nerve. FN: Facial nerve, CN: Cochlear nerve, SVN: Superior vestibular nerve, SN: Singular nerve.
- Demonstration of the internal auditory canal (IAC) and clinical application. (a): Right-side IAC demonstrated using the author's own hand model, showing the arrangement of FN, SVN, CN, IVN, SN seen from the medial/cranial side. (b): Left-side IAC hand model using the author's own hands seen from medial side, demonstrating the arrangement of nerves for teaching and bedside explanation. (c): Patient counselling demonstration for left-sided vestibular schwannoma, showing how the hand model is used to explain tumour origin and nerve compression. Black circles denote the internal auditory canal outline for visual clarity. IVN: Inferior vestibular nerve. FN: Facial nerve, CN: Cochlear nerve, SVN: Superior vestibular nerve, SN: Singular nerve. FN: Facial nerve, CN: Cochlear nerve, IVN: Inferior vestibular nerve, SVN: Superior vestibular nerve, SN: Singular nerve
RESULTS
Over years of use, the model has yielded:
Instant comprehension of IAC anatomy, Improved recall during exams, Clear understanding of nerve relationships, Better counselling for vestibular schwannoma, Student-to-student teaching (“ConfidENT learning”) , Creative adaptations for other ENT regions. The model has been demonstrated in Continuing Medical Education (CME) programs, workshops, and seminars, inspiring widespread adoption.
DISCUSSION
Teaching the IAC typically depends on cadaveric dissection, imaging, or expensive 3-D models—resources that may not be available in many settings.
A no-cost hand model provides:
Universal accessibility, portability, immediate reproducibility, tactile reinforcement, reduced complexity, high teaching impact. This approach democratizes anatomy teaching and encourages creative, no-cost solutions across medical education.
Once again, the author’s teaching philosophy applies:
“What your eyes couldn’t see, your brain couldn’t tell…
What your hands could teach, your mind could easily tell.”
CONCLUSION
The IAC can be made easy to understand using a no-cost hand model consisting only of one’s hands and a folded paper strip.
This method is simple, clear, reproducible, and ideal for teaching professionals, students, and patients. It represents a meaningful educational innovation that simplifies complex neuro-otological anatomy.
Ethical approval:
Institutional Review Board approval is not required as this study involves an educational hand model without clinical intervention or patient experimentation..
Declaration of patient consent:
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Conflicts of interest:
There are no conflicts of interest
Use of artificial intelligence (AI)-assisted technology for manuscript preparation:
The author confirms that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.
Financial support and sponsorship: Nil
References
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