My Learning Experience

When I entered residency training in Otorhinolaryngology-Head and Neck Surgery, all I wanted is to become a good ENT surgeon.  Through the years of training and seeing many patients with different diseases, voice cases interested me the most.  I even became a voice patient once which added more to my eagerness to know more about this subspecialty.  Our hospital does not have a very good foundation in voice subspecialty and in order for me to acquire knowledge and skills in the field that I want, I need to look for a competent hospital that can provide me with these.

The first time I've been to Seoul, I told myself that I would definitely be back. I love everything in Seoul, the people, rich culture and tradition, the places, and also the food.  The second time that I came to Seoul was an invitation to observe in one of their biggest hospitals. Then I thought, why not look for a hospital in Seoul that offers a training in the field that I've always wanted.  I have searched and found that there is one prestigious center that specializes in voice, the Yeson Voice Center.  Yes, I found a hospital but I don't know how to get in and where to start.  Maybe I am just so fortunate and this is really the path that I should take for Yeson Voice Center just so happened to be looking for an ENT specialist from the Philippines to be their trainee.  Without a doubt, I immediately applied for the position.

The training program is in cooperation with Korea Health Development Institute. They aim to give overseas medical doctors an opportunity to gain extensive medical knowledge and skills, while broadening their understanding about Korea and the country’s medical services.

A doctor's education never ends.  We need to pursue on continuing education to stay up to date and learn new advancements in our chosen specialty field.  A center that gives unparalleled opportunity to obtain broad knowledge and high skill is Yeson Voice Center.  The center is spearheaded by notable group of gentlemen with the best knowledge in the field of Voice.  The Director of the center is Dr. Kim Hyung Tae, Chairman of Board of Directors is Dr. Yoon Hee Ro, Associate Director is Dr. Lee Ji Wook, and and Associate of the hospital is Dr. Kim Hyun Soo.  The faculty is committed to excellence in research, teaching, patient care and advancement in the art and science of voice.  The training provides variety of clinical opportunities including assessment and treatment.  Exposure to have additional experience with major areas of specialized assessment strategies and medical and surgical intervention.  In my three months of training in Yeson Voice Center I look forward to acquiring as much knowledge and skills with the help of Dr. Kim Hyung Tae who directly supervises my training.

There are diverse patients seen in Yeson Voice Center and specialists are well trained to best evaluate and diagnose these cases.  They have Vocal Fold Paralysis; Dysphonia secondary to Vocal Cord nodule, Vocal Cord Polyp, Vocal Cord Cyst, Granulomatous Laryngitis, Reinke's Edema, Sulcus Vocalis, Laryngeal Papilloma, Laryngeal Cancer, and Laryngopharyngeal Reflux ; Spasmodic Dysphonia; and Functional Dysphonia.  The faculty are also highly specialized to perform different procedures using state of the art equipments.  Percutaneous Injection Laryngoplasty, Microlaryngeal Surgery, PDL Laryngeal Surgery, Voice Feminization Surgery and Botox Injection are done in the center, and I get to observe all of these procedures.  I am given the chance to see different cases and learn the techniques on how they are surgically managed.  A higher learning and more specialized skills that I can practice in the future.  Techniques that I can share to my fellow Filipino ENT, residents in training, and patients. 

In order to arrive at a correct diagnosis and plan of management, a meticulous examination are always done.  The center is equipped with the largest diagnostic facilities for voice examination.  They have equipments for computerized voice analysis, aerodynamic examination, digital laryngeal stroboscopes and nasopharyngoscopes of Kay Elemtrics.  They have also introduced high speed vocal cord color filming equipment and phonokinetic evaluation for the first time in Asia.In the afternoon, I get to observe in the examinations done at the Artceum for the clinical evaluation for voice: Psychoacoustic Evaluation, Phonatory Aerodynamic Test, Speech and Voice Acoustic Study, Voice Range Profile, Rhinolaryngeal Stroboscopy, Nasometer II, Screening Language Evaluation, Phonatory Pattern Screening Test, and Multichannel Phonokinetic Evaluation System. Their facilities are very much advanced which I will encourage our hospital to have in order to reestablish our voice laboratory.

During weekends, I get to see the beauty of Seoul.  At first glance, Seoul appears to be a sprawling concrete mass of high-rise modern buildings interspersed with historical treasures. But on a closer look, the city can be divided into numerous smaller districts with their own distinct character. 

There are many reasons why I love Seoul. They have a very rich culture and tradition.  The architectural traditions has been restored and maintained to its finest. A proof of how they value their history.  I have been  to some of their palaces and temples and I can't help but be amazed.  There is the famous Gyeongbuk Palace and Changdeok Palace, also the Bongeunsa Temple and Bulguksa Temple, each with its own identity and story to share.  

You can see people bustling around the busy streets of Seoul especially its famous places.  Seoul is one of greatest places to go shopping. You can see the diverse fashion sense of Seoulites.  They have big department stores like Lotte, Hyundai and Shinsegae, which are dazzling emporium selling all kinds of merchandise.  But for those who is in a budget, there are stores all over where you can easily splurge at a reasonable price.  Favorites would be Dongdaemun, Namdaemun, Insadong, and Myeongdong shopping district.  These places are usually crowded and being bumped around is very common.  Shopping can be very much tiring, and anywhere you can just see food stalls selling different kinds of street food.  Grab a bite and the experience is worthwhile.

I love Korean food.  You can try the traditional Korean dishes or even have international dishes.  The dining place can be just a tent, a stall near the street, small traditional home, or a classy restaurant.  They all serve good tasting cuisines.  Must try for me would be samgyeupsal (korean barbeque), ssambap, bulgogi, bibimbap, jigae, and the infamous kimchi of different varieties.  They have a wide range of food to choose depending on your palate. But most of their food are spicy.  Good thing, I like it spicy.

If you're looking for serenity, a walk along the Cheongyecheon Stream would be a perfect place. It is a 5.8 km remarkably quiet walk along the stream since it is 15 feet below the street.  There are small waterfalls, fountains, and overhead bridges.  Another place that I find amusing and romantic is the Namison Island.  The tranquil view of the island is captivating. For a little excitement, you can try to enjoy the rides at Lotte World and for more extreme adventure, Everland is a must go to attraction.  Also, at night, it is great to visit Seoul Tower to have a view of whole of the city of Seoul.

The Gangnam Style by Korean singer PSY was very popular all over the world at the time of my visit in Seoul.  Everyone is talking about it and you can hear it being played everywhere.  It's even a dance craze that most are raving about.  To have a better grasp of it, my coordinator arranged a good place for me to stay in Gangnam while I'm on my training.  I can see everyday how much fun it is at night as most young people go here to party and have couple of drinks with friends and sometimes party lasts till early morning. There are even many good restaurants and shops around the area.  I stayed at M Chereville Serviced Residence which is few minutes walk from Gangnam station.  One of the busiest subway station I have ever seen with a huge shopping area just within the station.  My room is very spacious and comfortable.  I have a small kitchen and even got my own laundry machine inside the room.  There is also an internet access so I can always keep in touch with my family.  It is a very convenient place for me and I guess anyone who's away from their own homes.

The whole experience would not be possible without the assistance of KHIDI and the staff of Yeson Voice Center.  It is truly an honor for me to be trained by Professor Kim Hyung Tae.  I admire your dedication and passion to the profession.  I hope that someday in the future I can be a good voice specialist like Professor Kim.  With great gratitude, I thank all the faculty and staff of Yeson Voice Center and KHIDI for the very warm welcome and making my stay in the Seoul a wonderful experience.  

Kamsahamnida! =)

Treatments offered

Treatment of different voice disorders requires special knowledge and expert skills.  The doctors in Yeson Voice Center can provide you the best quality of treatment when it comes to voice diseases.  The center is equipped with state of the art surgical technology that can manage any vocal fold lesion.

PERCUTANEOUS INJECTION LARYNGOPLASTY

Percutaneous injection laryngoplasty is a new method developed to improve the operating procedures using electromyogram.  Without the need of general anesthesia, this procedure preserves major vocal membrane and vocal layer, and allows for inserting an organic prosthesis in place.  The EMG needle helps to spot and insert the material, improving the voice dramatically almost permanently.

Advantages of injection laryngoplasty are: general anesthesia is not necessary, it only take 15-20 minutes, treatment is possible irrespective of patient’s health condition, hospitalization is not required, no incision needed, different treatments are available through different drugs in accordance to the patient’s condition, and insertion in the right area is possible depending on the illness of the patient.

Disadvantages are high cost of the medical appliance, knowledge and experience on EMG is needed, and high level of technique and experience is required.

MICROLARYNGEAL SURGERY

Microlaryngeal surgery or phonomicrosurgery has been developed since the 19^th century as the observation of the larynx through reflecting mirrors began.  Laryngeal mirrors provided the most significant part of understanding and treating vocal fold diseases.

Benign vocal fold diseases including vocal nodules, vocal polyp, sulcus vocalis, vocal cyst, and adhesive vocal folds are limited to the lamina propria which affects the movement of the epithelium that covers the vocal folds and the mucosa.

Submucosal Infusion Technique

Submucosal infusion is a technique which recovers the voice by separating the mucous membrane with lesion and the lamina propia of the vocal folds and preserving the lamina propia when performing the surgery.

Micro Mini-flap Surgery

As the microstructure of the vocal folds and the process of healing in benign vocal fold diseases have been demonstrated, studies have proved the significance of preserving the lamina propia of the vocal folds and the importance of vocal rest and rehabilitation.  As a result of these studies, surgical operations of the vocal folds including the micro mini-flap surgery which can bring the voice to original condition have been developed.

PULSED DYE LASER LARYNGEAL SURGERY

Yeson Voice Center acquired the Photo Genica SV PDL from Cynosure Inc. US. This equipment can perform laryngeal surgery without the need of general anesthesia.  PDL selects and solidifies only blood vessels at vocal band.  It does not damage the healthy tissue.  It selects and destroys only the abnormal tissue.

The 585 nm Pulsed Dye Laser Surgery guides the PDL with optical fiber and connects it through the digital electric laryngoscope channel so it does not harm laryngeal and surrounding tissue. 

Advantages of PDL Surgery are: only local anesthesia is required, day surgery is possible, no hospitalization required, bloodless surgery, safe and effective, excellent in bleeding control, no damage to laryngeal tissue, excellent restoration of tissue in surgical region, excellent in improving voice by rearranging collagen, takes only 20 minutes for the procedure, and painless during and after the surgery.

VOICE FEMINIZATION SURGERY

Voice feminization surgery is changing one’s voice to a female, and it is for those who are physically built as a male and also has a deep male voice, but whose actual sexual identity is a female.  This surgery therefore, are for those who have experienced abnormal hormone functions as a child and got affected with adrogenital syndrome or androphonia, or through the side effect of the hormone treatment for aplastic anemia.

The common male voice frequency is approximately 100-150 Hz and for females it is approximately 200-250 Hz.  The reason why the male voice tone is lower than females is because the males vocal cord is bigger and longer than the females.  Therefore, this treatment makes this vocal cord shorter and thinner on the basis of the three factors.

The new method of voice feminization surgery, called "Vocal Fold Shortening and Advancement of Anterior Commissure," is the world's first treatment that does not incise the skin and get the same result of modifying the vocal cord to a female shape using an endoscope.

This treatment which was developed by the Yeson Voice Center was presented at the Voice Foundation Association in The United States on May 29, 2007.  This VFSAAS differs from the previous methods in that it leaves less damage on the vocal cord tissue and incision is not required proving this is the best physiological method in increasing one's vocal pitch.

Voice pitch is determined by the size and length of the vocal fold.  To help you understand better, it is the same logic with a musical instrument, guitar.  Thick and long string makes a low pitch, thin and short makes a high pitch.  Male and female vocal fold sizes are different, male's is thick and long while female's is thin and short.  Vocal Fold Shortening and Advancement of Anterior Commissure was developed in Yeson Voice Center.  The surgical procedure is dissecting the anterior 1/3 portion of the vocal fold membrane, then it makes the high voice tone.

Their average vocal frequency increased from 137.3 Hz to 211.5 Hz, showing a 74.2 Hz increase in one’s voice frequency.  Also, different from the surgery methods described earlier, this treatment makes it possible for maintenance of matural phonation and even singing after the surgery.

There are no particular complications after the surgery, but there might be some foreign body sensations in the vocal cord and rough voice, pain in the neck, sputum and cough; but these are all temporary and with proper medication and time it will resolve.

Phonoplasty surgery should be operated through the most suitable method for each individual patient, and for this to occur, the vocal status after surgery must be predicted beforehand in order to increase a better result.

Also, the tone quality of the voice and resonance of the sound can be changed into a more female voice by changing into a more female voice by changing the shape of the pharyngeal cavity through the patient’s motivation, and by attending voice clinics and voice rehabilitations.

The most important thing about this process is that each patient should get voice feminization surgery from an experienced voice clinic, and a clinic which can provide voice rehabilitations; otherwise one cannot expect any voice improvement.  Therefore, patients must get voice feminization surgery by an experienced voice specialist.

Different Voice Disorders

With the expertise of the doctors and the availability of the most advanced diagnostic tools, Yeson Voice Center is able to meticulously define these different voice disorders.

VOCAL FOLD PARALYSIS

The vocal folds of the larynx are the major source of sound in speech.  This is controlled by cranial nerve 10, the vagus nerve.  The muscles of the larynx and vocal folds move together naturally to produce sounds , for breathing, and to prevent food from entering the trachea.  These are innervated by the recurrent laryngeal nerve and superior laryngeal nerve, both from the vagus nerve.

The vocal folds are brought together by the action of the laryngeal nerves.  The air pressure builds up beneath the larynx, generating a sound through the rhythmic opening and closing of the vocal folds.  However, when the nerves are paralyzed, the vocal folds do not open or close properly, leaving the airway passage and lungs unprotected.  This causes hoarseness and coughing because of food that can get to the trachea.

This condition is called Vocal Fold Paralysis, it can be unilateral wherein one side is paralyzed, or bilateral wherein both the vocal folds are paralyzed.

Aside from laryngeal nerve paralysis causing the abnormal movement of the vocal folds, there are still many other causes of this condition that should be carefully examined.  These are laryngeal mass, arytenoid dislocation secondary to trauma, damage to joints, congenital malformation, inflammation, infection, and scarred vocal fold.

It is important to examine the severity of the vocal fold paralysis, whether it can still recover and the time of recovery.  There are different procedures that can be done to evaluate the paralysis according to its most likely cause.  Brain computed tomography and brain Magnetic resonance imaging are performed to examine brain disorder, brain tumors, disorder of the central nervous system and the peripheral nervous system.  Cervical computed tomography to identify neck tumors and disorders in the blood vessels and nerves.  Thyroid function test and ultrasonography can also be done.  Laryngoscopy and laryngeal stroboscopy are done to identify congenital disorders, inflammatory diseases and other functional disorders.

The treatment for vocal fold paralysis started since 1911 by Dr. Wilhelm Brunings when he treated vocal fold paralysis by injecting paraffin to the muscle.  This treatment is used only mainly until 1970s because of its side effect, the formation of granuloma.  In 1915,  Dr. Erwin Payr then developed the method of operating the thyroid cartilage.  From then on, there was no systematic theory until 1950.  In 1974,  Dr. Isshiki established thyroplasty which became common.  Arytenoid adduction was then performed to 12 patients by Dr. Slavit and Dr. Maragos in 1992.

In 1977, the method of partially resecting the omohyoid muscle which is connected to the hypoglossal nerve branch and implanting it to the vocal fold muscle was attempted by Dr. Tucker.  This is also the method of replacing the paralyzed nerve in the vocal fold with another nerve.  However, it is not commonly used because it requires too much time for the vocal fold to recover its function.

Later in 1984, Dr. Ford attempted the method of injecting collaged into the vocal folds.  In 1991, Dr. Mikaelin introduced the method of using fat transplantation.

Today, the newest operative method used is the Percutaneous EMG Guided Injection Laryngoplasty.  This is developed and presented at the national and international conferences by Dr. Hyung Tae Kim, the chairman of Yeson Voice Center.  This method involves the injection of artecoll to the vocal cord ligament layer using electromyogram.

VOCAL DYSPHONIA

VOCAL NODULE

Vocal fold nodules are caused by strenuous or abusive voice practices especially those who use their voice in their profession.  This usually occurs bilaterally and often symmetrically.

Continuous hoarseness and fatigue are the main symptoms of vocal fold nodules.  Nodules do not cause pain or difficulty when swallowing food.  The nodules usually appear in the center of the vocal fold, the area that receives the most pressure when the folds come together and vibrate.  Vocal fold nodules do not grow over a certain size and thus do not cause breathing difficulties.

In this case, it is important to receive voice therapy that focuses on eliminating voice abuse and teaching the proper use of voice.  Nodules usually resolve with voice therapy itself.  When therapy fails, surgical treatments are then necessary.  Surgeries include Microlaryngeal Surgery and CO2 laser.  Currently, endoscopic microfracture surgery and pulsed dye laser are performed.  Postoperative voice rest is very important.

VOCAL POLYP

Like vocal nodules, a vocal polyp is caused by voice abuse.  It may be caused by a temporary damage or an upper respiratory tract infection.  Seen more commonly in adults than in children.  They can be sessile or pedunculated, edematous or angiomatous.

Vocal polyps can cause hoarseness, and the symptoms may vary depending on the size and its location.  In some cases, the symptoms occur broadly and severely, and disseminated polyps may result in breathing difficulties.

This lesion requires microlaryngeal surgery and pulsed dye laser to be removed.  When the cause is voice abuse, voice therapy should also be done.

VOCAL CYST

Vocal cyst is a mass made up of collection of mucus that is surrounded by a membrane.  It is found underneath the mucosa, within the superficial lamina propia, the layer that is important for normal voice production.

Cysts generally cause painless hoarseness.  The hoarseness results from irregularities in the vocal fold closure and vibration.  In some cases, the voice change may be accompanied by sensation of a foreign body at the level of the vocal folds, or feeling of wanting to clear the throat or cough.

Cysts are most commonly removed by microlaryngeal surgery and pulsed dye laser at the same time.  It is very important to remove the root completely to prevent any recurrence.

GRANULOMATOUS LARYNGITIS

Intubation granuloma is caused after a laryngeal surgery, bronchoscopy or an endotracheal intubation.  It is usually found at the back of the vocal fold over the part of cartilage.  At the beginning, the granuloma becomes larger in size but it later on regresses in size.  In many cases, the granuloma occurs bilaterally, and hoarseness is not severe.  This is more commonly found in females.

Vocal rest and steroids can improve the condition.  While the granuloma is growing, antibiotics can be of help.  If the granuloma does not improve after these, a mocrolaryngeal surgery or steroid injection after an incision using CO2 laser may be necessary.  The recently developed pulsed dye laser surgery can also remove the granuloma under local anesthesia.

REINKE”S EDEMA

Reinke’s edema is caused by chronic voice abuse and vocal damage.  This is also related to smoking.  The main symptom of this lesion is hoarseness.  Biopsy of the vocal fold is used to help in the diagnosis.  Reinke’s edema causes the vocal folds to swell giving them a sac like appearance.

Conservative treatment involves removing the source of irritant in the larynx, vocal treatments, and smoking cessation.  Surgeries include microlaryngeal surgery or CO@ laser which removes the sumbucosal edema to help restore the normal vocal fold tissue.

SULCUS VOCALIS

Sulcus vocalis is thinning or absence of a tissue covering the vocal cord required for vibration to produce sound.  This can produce a harsh, reedy hoarseness.  People with sulcus vocalis frequently exert unusual effort to produce voice, and to find it more difficult to be heard over a background noise.

Microlaryngeal surgery can be done to incise the sulcus vocalis.  Other options are injection laryngoplasty and recently, the pulsed dye laser surgery brings great outcome to patients.

LARYNGEAL PAPILLOMA

Laryngeal papillomas are benign epithelial tumors caused by infection with Human Papilloma Virus (HPV) type 6 and 11.  The disease is more commonly found in children that may have contracted it through vaginal childbirth from a mother with HPV.

In adults, symptoms are hoarseness, or strained or breathy voice.  Size and location of tumor dictate the change in the voice.  Breathing difficulties may occur but are usually seen in children.

In infants and small children, the symptoms of papilloma include weak cry, trouble swallowing, noisy breathing, and chronic cough.  Noisy breathing may be a stridor, which can sound like a whistle or a snore, and is a sign that the laryngeal and tracheal parts of the airway are narrowing.

Yeson Voice Center has implemented the Photo Genica SV PDL from Cynosure Inc. US.  This is used to perform laryngeal surgery without general anesthesia.  This pulsed dye laser selects and solidifies only blood vessels at vocal band and does not damage the healthy tissue.  It only selects and destroys abnormal tissues.

LARYNGOPHARYNGEAL REFLUX

Laryngopharyngeal reflux (LPR) is the inflammation of the larynx or pharynx caused by stomach acid or food backing up into the esophagus.  Symptoms are chronic hoarseness, frequent or dry cough, sensation of lump in the throat, and difficulty and pain swallowing food.

General treatments for LPR are diet modification to reduce reflux, medications to restrain stomach acid, and surgery to prevent reflux.

SPASMODIC DYSPHONIA

Spasmodic dysphonia is a voice disorder caused by the excessive tension in the laryngeal muscles.  They have breaking voice and face difficulty to start and continue communication.  Spasmodic dysphonia is often classified according to the age when the symptoms develop.  When symptoms develop before age 20, it is called infant type.  If symptoms develop after age of 20, it is called an adult type.

Many doctors thought that mental problems were the cause of spasmodic dysphonia because symptoms would get better when taking alcohol and tranquilizers, and get worse when being stressed or talking on the phone.

In the 1980’s, researches of the cranial nerve brought the thought that the cause of spasmodic dysphonia was the abnormal spasm of the laryngeal muscles due to the inharmonic function with the basal ganglia where the integration of the central nerves take place.  However, Dr. Ludlow, from National Institute of Neurologic Disorder (NINDS) of National Institute of Health (NIH), proved that the cause of spasmodic dysphonia is the abnormal nerve system in the nucleus tractus solitaries, so patients lose control of their vocal fold muscle which makes it hard to talk and breaks off sounds.

Spasmodic dysphonia is classified according to the symptoms and characteristics.  Adductor type accounts for approximately 80%.  It can be glottis, supraglottic, dystonia tremor or an adductor type with tremor.  This is the most common type and involves spasm of the muscles that close the vocal folds.  Glottis type reacts better than supraglottic type to Botox.  Abnormal involuntary co-contraction of the vocalis muscle complex, resulting in inappropriate adduction of the vocal fold exhibiting strained-strangled voice quality with abrupt initiation and termination, resulting in short breaks in phonation.

The abductor type accounts for 4%.   This is an action-induced inappropriate co-contraction of the posterior cricoarytenoid muscles resulting in  inappropriate abduction of the vocal fold.  This type exhibits effortful voice quality with abrupt termination resulting in aphonic whispered segments of speech.

Other types are of mixed type for 11% and respiratory dysphonia for approximately 2% or now known as paradoxical vocal fold motion..

For the examination of patients with spasmodic dysphonia, first, one will receive an acoustic vocal test.  Then a test will be performed to measure the muscular spasm of vocal cord when speaking, and examine excessive spasm or tremor of the laryngeal muscle using a laryngoscope.  Next is to measure the basic vocal frequency with acoustic tests and observe the vocal waveform through spectrogram.  Then an electroglottography and measure of resistance of aerodynamic test are done.  Laryngeal stroboscopy examines the movement of the larynx, and the laryngeal electromyography helps find the abnormal movements of the larynx and the vocal fold muscle.  High speed vocal fold filming system helps find the exact location of spasm.

There are 3 types of treatment for spasmodic dysphonia.  Medical treatment uses anticholine drugs, tranquilizer, baclofen, and dopamine antagonist.  However, these has serious side effects and are only used in serious myotonic disorders.  Surgical treatment includes hemilaryngectomy, thyroid chondroplasty, laser vocalis muscle cordotomy, and nerve stimulator transplantation.  All surgical methods do not cure completely, and it may relapse with few months or few years.  The third treatment option is injection of botulinum toxin (Botox) which is currently the most effective treatment.  However, this is a temporary treatment which improves the voice for a period of 3-6 months.  This requires continuous injections to maintain good speaking voice.

Few years ago, treatment involves injecting only certain muscles on the vocal fold or in one side of the vocal fold.  But there was no study on the effect on the cerebrum and the other side of the vocal fold tries to match the balance and creates spasm on the other side.  Hence, this treatment might make the vocal fold worse due to the side effect.

The treatment now has changed to multiple laryngeal muscle injections with Botox.  It normalizes the voice by injecting small amounts of Botox to the abnormal laryngeal muscles.  This extends the period of having a good voice and minimized the term of hoarseness after Botox injection, helping the normalization of voice by cranial reflex rehabilitation.

FUNCTIONAL DYSPHONIA

Functional dysphonia is the abnormal use of voice despite normal anatomy and function of the vocal folds and the larynx which produce the voice, and pharynx and mouth which produce resonance.  This can be related to abuse or misuse of voice or habituation of compensatory techniques developed from condition of the larynx.

This is often classified into 5 types.  The conversion aphonia, habitual hoarseness, inappropriate falsetto, vocal misuse/abuse syndrome, postoperative dysphonia, and relapsing aphonia.

Mutational falsetto under a normal laryngeal system causes the voice to be high pitched weak and thin like a voice of a female.  The voice is easily fatigues.  The voice tone stays high, monopitched and high pith songs can’t be sung.

It can be classified into 2 different factors.  Functional factors are caused by psychological problems like young males of pubertal age who fail to accept their adult role or suffer emotional stress from changes.  Organic factors are caused by abnormality in the vocal membrane like contractions or scars in the mucosal membrane of underdevelopment of the larynx.

When functional dysphonia is caused by functional factors, the vocal folds appear normal on laryngoscopy and stroboscopy.  The outer laryngeal muscles are excessively used to make a sound and the larynx elevates.  In organic factors, there are abnormalities in the mucous membranes or underdevelopment of the larynx and vocal folds.