TMD UNDERSTANDING THE GREAT IMPOSTER

Temporomandibular Joint Dysfunction

Understanding the Great Imposter

Relationship between occlusal proprioception and the neurologic effect

Understanding the relationship between occlusal proprioception and the neurologic effect at higher levels is essential in the understanding of TMJD symptoms that these symptoms are usually not in the joint itself, but of neuromusculature nature. Primarily in the masseter, temporal, medial and lateral pterygoid and digastric muscles. Evidence suggests that the basis of symptomatology is a disturbance of proprioception at a mid brain level.

Proprioception and the Brain Stem Reticular Formation

Located in the central part of the brain stem, the reticular formation is a tiny network of nerves the size of man’s little finger. All the major nerve trunks in the body have tendril like branches to the reticular formation. Afferent (carry nerve impulses from receptors or sense organs towards the central nervous system) sensory signals from all parts of the body go to the cerebral cortex by direct pathways ascended through the brain stem; however, they send collateral nerves (side branches) to the reticular formations. The cerebral cortex is the site of perception, thought and ability to respond to a stimulus with anything more than a simple reflex reaction. But directly stimulating the cortex will not awaken the brain. The reticular formation, also know as the reticular activating center (RAC) simply has one action to arouse the brain.

The Trigeminal Nerve

The Trigeminal Nerve (the fifth cranial nerve) is the largest of the cranial nerve, it contains 60% of the total nerve tissue of the twelve cranial nerves. It gives origin to three major divisions:

1. The Ophthalmic V1       
2. The Maxillary V2
3. The Mandibular V3  

It is the sensory nerve of the face, most of the scalp, the teeth, the mouth, nasal cavity, and the temporomandibular joint and it carries proprioceptive impulses from the masticatory muscles. It's motor branches supply the muscles of mastication and the other muscles such as the mylohyoid, anterior belly of the digastric, tensor veli palatini and tensor tympani. (An understanding of the TVP and tensor tympani you may refer back to my previous Blog TMD and the EAR and EYE Connection). 

There are many parasympathetic and sympathetic nerve fibers from the other cranial nerves that join branches of the trigeminal nerve. Its influence on the central nervous system is accordingly disproportionate to that of the other cranial nerves. The proprioceptive stimulation of occlusion is the dominant sensory input into the trigeminal system.

The trigeminal nerve is uniquely associated with the ascending activating reticular system. The primary sensory trigeminal fibers terminate in the reticular formation just medial to the spinal trigeminal nucleus. The spinal afferents from all levels terminate in the spinal and sensory nuclei of the trigeminal nerve. In voluntary movements the sensory nerves conduct impulses from the muscle spindle to a sensory area in the brain. Motor nerves then conduct impulses from the motor area to the masticatory muscles. Both nerve systems branch into the reticular activating system. RAS sends down efferent, (carry nerve impulses away from the central nervous system to effectors such as muscles or glands), impulses that either facilitate or inhibit the response. The reflex movement sensory impulses are transmitted immediately to motor nerves in spinal cord. One nerve activates the muscle and maintains its tone and the other nerve sensitizes the muscle spindle. Both voluntary and reflex mechanisms are under reticular activating system control. 

 

  

All evidence suggests that the reticular activating system has a most important role in regulating all motor activities in the body. It can modify voluntary muscle movements (controlled by the brain) or the reflex movements (controlled by the spinal cord). The importance of this voluntary and reflex arc on muscles of the face and jaw is seen in TMJD patients.

The fact that the RAS can act on the spinal cord reflexes distinguishes even further the role of noxious proprioceptive occlusal contacts (such as grinding or interferences due to mal-occlusion) as pathogenic sources to muscles. The reflex apparatus has two functions:

1. First, it generates automatic muscle movements. When noxious stimuli (i.e. occlusal prematurities) arrive at the spinal cord, they are instantaneously passed on to an adjacent motor nerve and travel back to the affected part of the body to jerk it away from the noxious stimuli. This nociceptive  (A nociceptor is a sensory receptor that responds to potentially damaging stimuli by sending nerve signals to the spinal cord and brain) reflex is designed to protect the body part from injury. The avoidance of the prematurity may protect the tooth from a noxious contact but significant accommodation of muscles and joints is often required.
2. The second function of the reflex system is to keep the muscles ready for action by maintaining muscle “tone”. This muscle tone postures the body part close to the area where function will occur. The muscle is in a state of partial contraction in anticipation of the work to be done. The muscle spindle regulates the resting tone. When muscle contracts, it squeezes the spindle; when the muscle relaxes the pressure on the spindle loosens. Change from normal tone causes the spindle to send signals via the sensory nerve to the spinal cord. The signal then excites a motor nerve to correct the contraction or relaxation of the muscle. This feedback system automatically maintains proper muscle tone.
   
   The tone of the muscle is adjusted to the functional demands on the muscle by nerve impulses which regulate the sensitivity of the spindle. Tactile sensibility for the trigeminal nerve is mediated by the sensory nucleus. Pain and thermal sensibility is mediated by the spinal nucleus or the trigeminal nerve. Under normal circumstances the reticular formation exerts a restraining influence on impulses conducted by the trigeminal as well as by the spinal nerves. It is obvious that if the tonic activity of the reticular formation is disturbed by noxious proprioceptive interferences the restraining influence of the reticular activating system on sensory impulses conducted by the trigeminal nerve will be significantly affected.

It is important to have a thorough understanding of the afferent and efferent neuromuscular connection between occlusal proprioception, the trigeminal nerve, reticular activating formation, cerebral cortex and skeletal muscles. Many of the dysfunctional conditions suffered by patients with pathologic occlusion is explainable when the neuromuscular mechanism is understood.


References:
1.  Chan C.A.: "Diagnostic Principles" Level 2 Occlusion Connections, Las Vegas, NV.
2.  Jankelson, R., "Neuromuscular Dental Diagnosis and Treatment", published by Ishiyaku EuroAmerica, ST Louis, MI. 2nd edition 2005

HOW YOUR SMILE CHANGES WITH AGE

HOW YOUR SMILE CHANGES WITH AGE and the oral obstacles that lead to an aging smile

Mmmmmm…., unlike a 1983 Chateau Margaux (Vintage Red Bordeaux wine) that improves with age and starts to show its beauty after 20 some years our smile, unfortunately, does not improve with age. That lustrous, lambent smile we used to have in our teens has succumbed to the ravages of time and bad habits and eventually left us with one that we now try to hide. Fortunately, today there are more options to improve one’s smile at any age, and give you back that gleaming white ear-to-ear grin.

So what are the causes of an aging smile? 

Discoloration:  The color of our teeth is influenced by a number of factors. Number one factor is that ever so popular cup of Java we have to have in the morning and throughout the day in order to function. Other causes that contribute to the staining of our pearly whites are Tea, Chocolate, Red Wine and Smoking. So can extended exposure to certain medications. Among other things are root canal treated teeth and teeth with old fillings and of course dental decay.

Gum Recessions: That long tooth appearance is due to a receding gum line which can be due to a number of reasons such as self inflicted habits, gum disease and grinding. The empty space between teeth that have receding gums are called black triangle, which makes the smile appear much older.

Fillings: The unfortunate few of us had cavities filled since our childhood and throughout adulthood. Some of these old, silver fillings have discolored the teeth to an ugly black back tooth.








Crowding: Misalignment of teeth or incorrect relation between the teeth of the two arches.

Periodontal Disease: Because of neglect, or even genetic factors, bone loss around the teeth can cause tooth loss, crowding and shifting of teeth.

Ugly Gums: Asymmetrical gum tissue, where the gum line is lower on one tooth than it is on the other. "Gummy Smile" which simply means to much gum tissue covering the tooth.

Grinding: Nothing causes an aged look more than worn-down teeth. It is one of the most problematic dental issues that if not caught early could lead to more severe symptoms such as headaches, clicking of the joints, dizziness, neck pain and more. Grinding causes wear on teeth which lead to a collapse of the bite. This will cause a loss of facial muscle tone and sagging of the muscles.

Fortunately, today’s dentistry can offer many solutions to the above mentioned obstacles to pave the way to a perfect, healthy smile. With procedures such as:

Whitening:  It is the simplest solution to a dazzling white smile. There many systems out there that will help you – from inexpensive at-home bleaching trays and whitening strips to professional laser bleaching in dental offices that give immediate results. It is always advisable to have a dental examination prior to any whitening procedure. One reason: Bleaching teeth that have gum recessions can cause sever sensitivity and pain.

Orthodontics:  It is never too late to get your teeth in line. This doesn't mean you have to prepare yourself for a couple of years of metal braces in adulthood. Today’s most popular teeth-straightening methods such as “Invisalign” and Cosmetic Self Ligating Brackets yield results much quicker and more convenient.

 

Tooth-colored fillings:  If you’re a senior, a baby boomer, or even a Gen X’er, chances are your back teeth are chock full of silver-mercury fillings. These fillings-reminder of your misspent, candy-prone youth in the years before widespread water fluoridation- once seemed like perfectly reasonable foreign objects to have in your mouth. But not today. Today these metal nuggets are considered outdated, in spite of your dental insurance opinion, which would rather pay for the less expensive silver fillings. They are outmoded not just because they are blackened and rough and ugly, it is because they have got competition: natural looking, tooth colored fillings which literally bond to the teeth.

Porcelain Veneers:  These are wafer-thin shells of porcelain that are bonded onto the front side of the teeth that are discolored, worn, chipped or are out of alignment. They are the fastest way to correct crooked, misaligned teeth, sometimes also called “Instant Orthodontics”. With proper care they should remain bright white for many years.

Before

After

Your teeth may be white and straight but other problems can stand between you and a spectacular smile. 

One of the most problematic dental issues is the misplacement of the jaw, which can result in teeth grinding, clicking joints, headaches, dizziness, and so on. This problem is also known as TMJD (Temporomandibular Joint Dysfunction). It is a tooth born problem that affects the muscles, nerves and joints and eventually the whole body could overcompensate for this whole misalignment.

From this misalignment, the cosmetic effect follows. The muscles in a bad bite are not in their right place, and the teeth may try to compensate by shifting, which can lead to crowding. In other instances if teeth can’t shift they can break. Now, if you had your teeth veneered you can imagine what will happen.

Correcting this problem via a Gneuromuscular approach can and will resolve this problem and give you a long-lasting and healthy smile.

Selecting a cosmetic dentist

  

Cosmetic dentistry is not taught in dental schools and it is not something that is mastered by one day lectures. There are criteria’s that substantiates the cosmetic dentist’s experience and expertise. There are many dentists who say they do cosmetic dentistry, but you want a dentist who has received training from an institute where they teach this kind of work. It is best to ask the dentist you have chosen for his training he or she may have received, their experience and expertise. Ask them to show you their own gallery of cases they have done and not a fabricated album they have purchased from dental vendors. Ask them for references of patients they have done cosmetic work on. Remember it is your smile, your most important possession you are placing into their hand.  

NEUROMUSCULAR APPROACH IN THE TREATMENT OF ANTERIOR OPEN BITE

Neuromuscular Orthodontic approach in the treatment of Class II, pseudo Class III anterior open bite and mandibular high plane angle and the prevention of surgical intervention:

   Commonly conventional orthodontics focuses on tooth to tooth relationship and a horizontal development with the teeth in habitual occlusion. To assist the progress of such a movement in a crowded, skeletal Class II situation there must be available space for this movement to take place. Standard of care in these settings dictates the extraction of four bicuspids or second molars in an adult dentition.

   Further more traditional orthodontic treatment of Class II anterior open bite with high mandibular plane angle most often requires orthodontic treatment and double-jaw surgical intervention to reorient the occlusal plane toward normal. The principle of changing the occlusal plane has provided a means to improve the functional and aesthetic results for the correction of this type of facial deformity and mal-occlusion.

   However, moving teeth horizontally and or surgical intervention whether extraction or double jaw surgery, does not address the functional six dimensional skeletal relationship of the mandible to the cranium (vertical, antero-posterior AP, lateral, pitch, yaw and roll), normal muscle function and normal temporo-mandibular- joint position.

Why not start from a physiologic relationship prior to orthodontic intervention?

  As a dental practitioner, "physician of the mouth", it is an absolute necessity to treat all three components of the stomatognathic system to create an environment for synergistic function of teeth, temporomandibular joints and the neuromuscular system by adhering to the five principles of physiologic occlusion¹.

1. Acknowledgement of the various musculoskeletal occlusal signs and symptoms
2. Identification of an optimal starting point for diagnosis and treatment-"PHYSIOLOGIC REST"- without manual intervention
3. Recognition of a physiologic mandibular opening and closing on a Neuromuscular Tragectory along an isotonic path for stability at a terminal contact position.
4. Micro-Occlusion; eliminates the afferent and efferent noxious proprioceptive stimuli of occlusion during mandibular closure with freedom of entry and exit.
5. Ability to objectively measure and record muscle and postural responses of the mandible accurately in establishing an occlusion.

  One of the cardinal discoveries in the past years of research has been that there exists a six dimensional relationship of the mandible to the skull as it is dictated by the occlusal position. Any change in these six dimensions can affect the relationship of the mandible to the skull, condylar to disc relationships within the glenoid fossa of the TM joint complex, the masticatory and facial muscles, tongue position and swallowing and neck/shoulder postural balance. 

Numerous musculoskeletal dysfunctions that could arise in dimensional change of mandibular/cranium relationship include:

• Headaches
• TMJ pain and noise
• Limited opening
• Vertigo (Dizziness)
• Tinnitus (Ringing in the ears)
• Dysphagia (Difficulty swallowing)
• Cervical pain
• Facial pain
• Postural problems
• Paresthesia (numbness) of fingertips
• Nervousness and insomnia
• Clenching and grinding
• Tender and sensitive teeth
• Pressure behind the eyes

   It is of utmost importance before commencing with treatment that the clinician should take these signs and symptoms into consideration and be aware of the changes in mandibular/cranial relationship which could ill affect the neuromusclular and skeletal correlation.

The prevalence of skeletal distortions in these patients become apparent once the musculature is deconditioned and the neuromuscular cervical neck relationships are relaxed to allow a more accurate assessment of the mandibular/occlusal relationship to the cranium. 

Necessity of objective assessment in determining a starting point:

   Common fault of many clinicians is by trying to handarticulate the diagnostic casts into occlusion for establishing a reference point for treatment planning and the type of restorative, orthodontic appliance and what orthodontic treatment to implement. This has shown not to be an accurate means to determine a true physiologic dental/skeletal Class I, II, or III typing of the malocclusion. Muscle imbalance, joint pathology, mal-occlusion, worn dentition, and postural imbalances of the head, neck, shoulder and hip have shown to influence the relationship of the upper and lower jaw ultimately the relationship of the diagnostic casts. Hence, without any clear orientation and reference starting point to properly relate the study models, it makes it impossible to properly make an accurate diagnosis and decide on a proper treatment course of action and the clinician should avert relying on intuitive subjective assessment by relating the casts in a pathological bite position.

   Unstable muscular functioning, joint pathology and torquing and twisting of the mandible due to sustained muscle contraction and their chronic shortening are not fully comprehended and remain undiagnosed. Electronic measurement of mandibular movement and masticatory muscle function provides invaluable objective quantitative database for diagnosing the existence and extent of myostatic contracture and skeletal malrelation. These data can then be used to design and monitor therapy and enhance treatment therapy.

K7 Myotronics: Computerized Mandibular Scanning (CMS) and Electromyography (EMG)

   CMS or jaw tracking and electromyography (Myotronics, Kent, WA)² are computerized measuring and recording instrumentation, together with an understanding of neuromuscular principles³, give clinicians the ability to provide an objective comprehensive diagnosis and allowing them to visualize jaw positioning combined with muscular responses.

   Collecting objective CMS and EMG data is the first step in the analysis and understanding of mandibular movements and physiologic positioning. Interpreting the data and correlating it to clinical applications is just another step to optimal treatment outcomes.

CMS measures jaw movements and locates mandibular position in space and it is displayed in a three dimensional spatial data on a computer screen. A small light weight magnet placed in the lower anterior vestibule behind the lower lip can be tracked with sensor array.

EMG measures the status of muscle by recording action potential levels of muscle pairs such as the left and right temporalis anterior, masseter, digastric and the cervical neck. These action potentials are displayed graphically pre and post treatment. 

Case Study:

Neuromuscular Instrumentation used to resolve jaw mal-alignment prior to orthodontic treatment

  The malocclusion with hyper divergent facial pattern or high angle are difficult to correct without combined orthodontic and orthognatic surgery approach. Treatment of patients with this type of skeletal pattern is very challenging, especially in adults who are beyond their facial growth. A surgical approach in patient who are beyond active facial growth is a viable and realistic option which permits the practitioner to attain reasonable aesthetic results and stable occlusion.
The orthopedic and orthodontic treatment of Class II high angle case requires a complete evaluation of the contributing factors.

   A 39 year old female presents with severe headaches in temporal region, forehead and back of the head, amongst other symptoms. She also complained of clicking in her left and right joints, inability to open wide, and awakening with dry mouth and that she does not like the looks of her face and smile.

She was evaluated by two orthodontist and one oral surgeon who had recommended orthognatic surgical intervention and orthodontics. When evaluating and talking to patient it became apparent that the patient wanted to prevent surgical intervention at all means. This case indicates the importance of objective diagnosis and understanding of muscular limitations, joint pathology and importance of validating vertical dimension increase and its accompanying horizontal change prior to establishing a bite position to prevent misdiagnosis and treatment of jaw alignment. Using conventional tooth-to-tooth subjective orthodontics and surgical intervention to establish jaw relationships is no longer acceptable to those suffering and paining patients.

  Challenges and Treatment Goals

• Identifying an optimal physiologic starting relationship between the upper and lower arches
• Muscle imbalances due to muscular pain, joint dysfunction, mal-occlusion and skeletal torques 
• Advance the mandible with control of the vertical dimension
• Reduction of hyperactive muscle activity and removing the skeletal torques and skews of the jaw mal-alignment in six dimensions
• Temporomandibular Joint pathology
• Postural imbalances
• Build a stable and functional occlusion: establish Class I molar and cuspid relations with competent lips and an aesthetically pleasing smile.

 Objective Assessment and Determining a Starting Point

   Varying degrees of muscular dysfunction, pain and joint derangement resulting from sustained muscle contraction and chronic shortening of muscles as they pull the mandible to a pathological occlusion clearly establishes the need for being able to objectively evaluate an orthodontic case prior to commencing with treatment.

Due to these hidden implications the orthodontic clinician cannot rely on intuitive subjective determination to start treatment from hand articulating the casts in a pathological bite. This can lead to misdiagnosis and failure and relapse. Neuromuscular orthodontics emphasizes how the muscles, jaw joints and teeth affect one another and to find a physiologic relationship before aligning the teeth to one another. 

Treatment Plan

In order to establish a proper treatment outcome, these cases need to be treated in two phases. Phase 1 comprises of finding the proper physiologic relationship of the mandible in six dimension and how it relates to the cranium. Establishing a starting point from where orthodontic treatment can commence. Elimination of muscle tension, patient symptoms and the achievement of a proper posture.

Phase 1:

1. Radiographic series for TMJ/orthodontic, study models and pre-treatment photographs 
2. K7 (Myotronics Inc.) workup and TENS to establish an Optimized Bite®⁴ 
3. Fabrication of a lower Gneuromuscular Orthosis
4. Establish proper mandible to cranium to cervical posture
5. Eliminating muscle tension and establishing a physiologic rest
6. Eliminating patient symptoms 

Guidelines for the fabrication of a Lower Gneuromuscular Orthopedic Repositioning Device⁵

The main function of an anatomical orthosis is directed toward orthopedic realignment of the mandible to the cranium, stabilizing the temporomandibular joints and return to normal physiologic function void of any craniofacial and cervical musculature strain. For the anatomical orthosis to be effective it needs to follow methodical principles of design specific to the TMJ dysfunctional patient. These design parameters are based on the four main categories of TMJ dysfunctional patients:

1. Cervical Problem
2. Primary TMJ Disorders
3. Class II Div 2
4. Anterior Open Bite

Phase 2:

1. Establishing proper maxillary and mandibular arch forms by means of expansion (if indicated)
2. Level and align maxillary arch
3. Incremental orthopedic vertical eruption of lower teeth and bone
4. Level and align lower teeth
5. Finishing which includes proper dental and skeletal Class I relationships, proper occlusion void of occlusal interferences, normal mandibular range of motion, and lack of muscle hypertonicity.

Palatal expansion was achieved by means of Max 2000 and Innovation C brackets

Case Finishing

Previous specialists were determined that this case could not be treated without surgical/orthodontic intervention. Once a physiologic bite relationship was determined, a diagnosis and treatment plan was established for proper orthodontic/orthopedic mechanics and appliance design to avoid jaw surgery. With a  neuromuscular approach it was possible to objectively attain a proper mandibular relationship in six dimension and related it to the cranium. With the help of an orthosis that position was stabilized and maintained throughout the phase 2 of orthodontic/orthopedic treatment and the establishment of a proper occlusion and a Class I skeletal and dental relationship.

Summary

The right diagnosis by employing computerized measuring and recording equipment allows us to objectively identify the components of skeletal deformity and how it is being affected by mal-occlusion. As long as mal-occlusion controls the balance of the musculo-skeletal system, mandibular jaw open and closing pattern will be posterior to an isotonic path of physiologic closure. This over time will result in muscle foreshortening and eventual muscle spasm and pain. The correctness or incorrectness of the human occlusion affects the postural relationships and entities of the body system. Optimizing the mandibular position and its surrounding neuromuscular system will increase case stability and improve long term retention. Logic dictates in order to increase vertical dimension and its accompanying horizontal change in mandibular position, one has to be able to objectively verify and compare both positions in pathology and health. As health care provider we have a professional obligation to our patients and the profession of dentistry to make proper diagnosis to help bring quality dental health free of the disruptive pains of temporomandibular dysfunction to our patients.

"START WITH THE END IN MIND"

References

1. Chan C.A.: 5 Principles of Physiologic Occlusion, Level 3 Treatment Planning, Occlusion Connections, Las Vegas, NV.
2. Mytronics Inc., Kent, Wa., "Helping building the perfect bite"
3. Jankelson, R., "Neuromuscular Dental Diagnosis and Treatment", published by Ishiyaku EuroAmerica, ST Louis, MI. 2nd edition 2005
4. Chan C.A.: Optimized Bite, NM Bite Refinement Level 5 K7 Practicum, Occlusion Connections, Las Vegas, NV.
5. Chan C.A.: NM Work Up Protocol For The TMJ Dysfunctional Patient, Principles Of Physiologic Occlusion, Level 3 Treatment Planning, Occlusion Connections, Las Vegas, NV. 

HEADACHES AND YOUR BITE

Not Another Headache!

Is it Nerve or is it Muscle?

One in eight Americans suffer from recurring headaches that are so severe they cannot carry out normal living! An estimated 80% of all headaches occur from muscle tension. These are some questions I ask my patients that I see for their initial consult:

1. Did you know that many tension headaches are related to your bite?  
2. Do you usually blame it on stress? 
3. Do you blame it on aging? 

This article explains how headaches can result from dental stress and how using a neuromuscular approach can help many headache sufferers.

     Headaches are our number one pain problem in the United States. Approximately 40% of all “healthy” individuals suffer from chronic headaches. Head pain is not new. Early civilizations relied on magical potions and spells to cure headaches. In severe cases, holes were drilled in the skulls of headache sufferers so that the evil spirits, which were believed to be the cause of the pain, could escape. However, over the years we have learned much about what causes headaches and how to treat them. Today, there is a growing realization that a common cause of tension headaches is a bad bite.

Headaches from Dental Stress

How can your bite cause a headache? Tension headaches result from muscle strain, or contraction. When muscles are held tight for long periods of time they begin to ache. Headaches from dental stress are a type of muscle tension headache. A tension headache may be on one or both sides of your head. Or, it may surround your head as if a steel band were wrapped around it. The pain feels like a dull, non-throbbing ache.

Specific signs, which indicate that the headaches may have a dental origin, include:

·         Pain or pressure behind the eyes

·         Sinus problems

·         Tinnitus (ringing in the ears)

·         Clogging or stuffiness of the ears, or subjective hearing loss

·         Pain and/or sore jaw muscles

·         Stiffness or soreness in the neck, shoulders and back

·         Vertigo (dizziness)

·         Grinding and clenching of teeth

·         Sensitive teeth

·         Clicking or popping jaw joints

Tired Bite

The muscles, which control your jaw and hold your head upright is very complex. Many people do not realize that every time they swallow, their upper and lower teeth must come together in a firm way to brace the jaw against the skull. We swallow over 2000 times each day and night! If your bite is unstable, as from poorly aligned teeth or even a missing tooth, the muscles must work harder to bring the teeth together. Most people take a vacation from work when they tire out-but your jaw muscles never get a break! The overworked muscles become strained. When muscles are under constant strain, they eventually become painful.

Muscle Imbalance

Other muscles may also become involved. Your head is delicately balanced on top of your spinal column by muscles of your jaw, neck, shoulders, and back. Your head weighs approximately 15-17 pounds the weight of an average bowling ball! Imagine your head as a baseball balanced on top of a pencil by a number of rubber bands. When muscles are tense, they shorten. Now imagine shortening just one of these rubber bands. Some rubber bands would stretch, some would shorten, and the baseball would throw off kilter! Similarly, when even a single jaw, neck, or shoulder muscle becomes shortened, all of the other muscles are forced to overwork to keep the head balanced on top of the spinal column. We see then that dental headaches originate from an unstable bite, which cause the muscles of the jaw, head, and neck to overwork and become painful. Once the muscles become painful, a vicious cycle begins. The pain makes you fell tense and uptight. This worsens the muscle spasm, which in turn increases the pain.

Dental Treatment

Neuromuscular dentistry is nothing new. Actually, it has been around for some 30+ years, but is not the traditional approach to patient care in dentistry. Neuromuscular Dentistry (NMD) is a term applied to techniques that expand upon the more traditional approach to dentistry that is more mechanically oriented. NMD places the occlusion where the muscles that control jaw position are at their best for optimal function and comfort. Neuromuscular dentistry is an evidence based approach. With the help of objective diagnostic evaluation (K7 Instrumentation, Myotronics Inc.) and the use of TENS (Trans-Electrical-Neural-Stimulation) an orthopedic splint is fabricated based on the individual patient problems and symptoms and not a one size fit all "splint". 

In future Blogs will be on the diagnostic instrumentation that is being used in Neuromuscular dentistry.

TMD and the EAR and EYE Connection

TMD and the EAR and EYE Connection

To fully appreciate the TMD and the EAR and EYE connection, it would benefit to look at their commonality in nerve innervations.

The Trigeminal Nerve (V): It is further subdivided into three branches:

1.      Ophthalmic Division (V1): It is the upper division of the Trigeminal nerve system. It has three major branches:

a.       Lacrimal nerve cries sensory information from the lateral part of the upper eyelid, conjunctiva, and lacrimal gland.

b.      Frontal

c.       Nasociliary

2.      Maxillary Division (V2): It is the middle division of the Trigeminal nerve and gives general sensory to the nerve branches to the zygomatic, infraorbital areas (branching further off to the outer nasal, upper lip areas), upper teeth, eye, palatal, posterior nasal areas, pharyngeal area and the meningies.

3.      Mandibular Division (V3): It is the lower division of the Trigeminal nerve and gives sensory the buccal, tongue, lower teeth, frontal ear and acoustic areas, the temporomandibular joint areas and meningies.

a.       It also caries motor branches to medial pterygoid (further to Tensor Veli Palatini and Tensor Tympani), lateral pterygoid, masseter, deep temporal, front area of the digastric and mylohyoid muscles.

The Facial Nerve (VII): Innervates muscles of the nose, buccinators, rhisorius, obicularis oris, muscles of lower lip and chin, platysma, and posterior area of the digastric.

There are three types of Pain:

1.      Vascular------- 10%

2.      Neurologic---- 10%

3.      Muscular------ 90%

The primary etiology of muscle pain is due to sustained muscle contraction resulting in vascular entrapment. Blood flow is impaired, oxygen is depleted and anaerobic metabolism starts.

The EAR Connection:

Eustachian Tube dysfunction: The Eustachian tube is the connection between the middle ear and the pharynx. It has three functions which are the aeration (equalizing pressure), clearance, and protection of the middle ear. Pressure equalization being its main option is regulated by three muscles including the Tensor Veli Palatini (TVP).

Patients suffering form TMJD often complain of a hearing loss, fullness isn the ears, and hypersensitivity to sound (hyperacusis). The TVP is innervated by the V3 division of the trigeminal nerve (motor branch) and lies in close anatomical proximity to the medial pterygoid. When there is pain occurring from primary pain source such as the temporalis, masseters, and medial pterygoid muscles, the effects spread to other muscles that share the same nerve supply. Dysfunction in muscles causes excitation and resulting in unnecessary sustained contraction of a muscle. In the case of the TVP muscle this sustained contraction causes the lumen of the Eustachian tube to remain patent at rest and pressure build up. This will give rise to the complaint of fullness and pressure in the ear and hollow sounding voice, but no changes in hearing. The closeness of the TVP to the medial Pt muscle is of great importance. Any chronic contraction of the medial Pt can impair normal function of the TVP. This in turn will prevent normal dilation of the Eustachian tube resulting in an inability to equalize the middle and outer ear pressure. Patients may complain of ear pain in a rapidly descending airplane and when scuba diving.

Displaced Condyle (retruded) and Mandibular-Malleolar Ligament (MML): A change in vertical dimension affects condylar position within the glenoid fossa. Teeth dictate the relationship of the lower jaw (mandible) to the upper jaw (maxilla) when teeth are in contact. A deep bite/over closure will translate the condyles back within the glenoid fossa resulting in compression of the retrodiscal tissue. The patient’s impression is pain in the ear (otalgia). The MML also plays a role in ear complaints. This ligament connects the neck and anterior process of the Malleous (hammer shaped bone in the middle ear, part of the ear ossicles) to a part of the capsule, the disc, and sphenomandibular ligament (ligament between the sphenoid bone and the mandible) through the small channel known as the petrotympanic fissure. A change in mandibular posture can affect the tension of the MML which in turn affects the movement of the ear ossicles. Many patients will complain of pressure and/or ringing in the ears when moving the lower jaw forward. The petrotympanic fissure is a communication from the middle ear to the glenoid fossa (the cavity where the joint is) and it is locate behind the condyle. In addition the fissure also contains the anterior tympanic artery which supplies the tympanic membrane (ear drum) and chorda tympani (branch of the Facial nerve VII). It also contains lymph channels. A posterior displacement of the condyle results in an increase in Tinnitus and Vertigo.

There is a mechanism that protects the inner ear form excessive sound. This protection is achieved by certain intratympanic muscles. Among them the tensor tympani muscle which is also supplied by a segment of the trigeminal nerve. Again when there is deep somatic and visceral pain occurring from a primary pain source such as the muscles of mastication, the effects spread to other divisions of the same neural segment. The action of tensor tympani is to pull on the tympanic membrane to increase its tension to reduce the movement of the ossicles when loud sound is present, hence protection of the middle ear. A dysfunction in this muscle will result in sensitivity to loud noise.

The EYE Connection

Patients suffering from craniomandibular dysfunction often complain of pain behind the eyes. The back portion of the orbital bony complex contains the greater and lesser wing of the sphenoid bone. The bones where the lateral and medial pterygoid muscles insert lie just below them namely medial and lateral pterygoid plates. Chronic contracture of these muscles could result in the torquing action of the sphenoids. Another recent finding that also could lead to retro-orbital pain is the Spenomandibular muscle. It originates from maxillar portion of the sphenoid bone and inserts into the internal oblique line of the mandible.

Bruxism In Children

Bruxism in Children

And recognizing the “Allergic Child”

A frequent question that I get asked by parents is “why my child is grinding”?

I am dedicating this to the late Dr. James F. Garry, a pioneering pediatric and TMJD dentist, the co-inventor of the “Nuk Sager Nipple”. And teacher and mentor to many dentists and doctors, including my self and my mentor Dr. Clayton Chan.

Studies have shown that 20% of non-allergic children were grinding teeth in comparison to 60% of children who were allergic. Dentists commonly believe that the cause of grinding is a “mind thing” due to local irritants, systemic factors, occupational factors, or a combination of these. Allergies as a factor have been ignored by many.

Listed are frequently seen facts that lead to bruxing:

• Mouth breathing – causing dry mouth and lessened flow of saliva, thus diminishing the need for swallowing
• Allergic itching or thickening of the palate and ears – bruxing relieves those symptoms
• Negative pressure build up in the middle ear cavity with auditory tubule dysfunction causing swelling of the mucosa in the Eustachian tube
• Eruption of secondary dentition and exfoliation of the primary and the attempt to establish contact of greater number of teeth

It is imperative to know that in a growing child that is hypersensitive like an allergic child, metabolic changes in the affected areas interfere with normal growth and development. The most common dental manifestation is malocclusion caused by chronic mouth breathing as a result of upper respiratory tract edema. This will lead to, if untreated, to a neuromuscular imbalance between the lower jaw and the upper jaw. The patient may accommodate for many years as he/she are growing, then suddenly develop myofacial pain dysfunction and TMJD.

Recognizing the allergic child: “Listen and Observe”!

  

Most allergic children can be recognized by the following:

• Allergic shiners bellow the eyes (dark lines)
• Intermittent hearing difficulties
• Complaint of stuffy ears, full ears, popping ears, fullness of head, vertigo
• Loss of smell and taste
• Sounds of an allergic child: nasal speech, constantly clearing throat, wheezing, frequent gulping
• Open mouth syndrome
• Forward head posture
• Shoulders are hanging and rolled forward
• Body seems bend and collapsed
• Adenoidal facial expression
• Teeth of the upper jaw are forward and retrognathic lower jaw
• Lower lips dry and rolled
• Bed wetting
• Snoring
• Sleep apnea
• Growth failure

In children, growth failure and short stature are the major manifestations of Growth Hormone deficiency, where the most intense period of growth hormone release is shortly after the onset of deep sleep. An allergic child that is a mouth breather has insufficient deep sleep stages.

As always, a primary diagnosis should come from your physician and, or pediatrician. A dentist’s role should aid in primary recognition and making the parent aware of these problems and recommend appropriate medical evaluation of the child. 

IS SURGERY THE ONLY OPTION?

Over the years practicing orthodontics and treating mal-occlusions and TMJD (temporomandibular disorders), treatment of the Class III (under bite) type of mal-occlusion has been the most rewarding experience, having a patient or their parents thank me for saving them from surgery. My goal is to inform the consumer that there are alternatives to surgery, not always but in majority of cases.

What is a Class III mal-occlusion? 
Class III malocclusion is considered to be one of the most difficult and complex orthodontic problems to treat. Prevalence of class III malocclusion in Caucasians ranges from 0.8 to 4.0% and rises up to 1213% in Chinese and Japanese populations. Skeletal class III malocclusion may either be associated with a maxillary retrusion (shorter upper jaw), a mandibular protrusion (longer lower jaw), or a combination of the two.
A poor facial appearance is often the patient's chief complaint, but may be accompanied by functional problems, temporomandibular disorders, or psychosocial handicaps.




Majority of these cases end up as surgical cases. The treatment usually involves a bilateral saggital split osteotomy of the lower jaw and/or advancement of the upper jaw with a Le Fort I osteotomy with pre-surgical and post-surgical orthodontics.



The surgery usually takes about seven hours to perform. The post-surgical complications like any surgery are nausea, numb upper and lower jaw, swelling, bruising, drooling, nose bleeding. Patients are restricted to soft and blended food.

But is this the only treatment option?

Case Report:
Patient L.A. 11.5 years of age presented to my office in 2010 for a 3rd opinion on his orthodontic treatment. The two previous orthodontists had recommended to hold off with treatment until patient reaches 16 years of age and at that time commence with pre-surgical orthodontics and surgery once initial alignment was completed.
After gathering the necessary records I came to the conclusion that this case could be treated non-surgically. A final consultation was scheduled and I discussed my plan of action which included of:

Phase I, treatment with a modified Tandem appliance to promote growth of the maxillary jaw forward, which is indicated in the mixed dentition stage.



Phase II, commencement with straight wire braces and the addition of CS 2000 springs in later stages of treatment.


Patient's parents agreed to my recommendations and were happy that the possibility of surgery was reduced.
L.A. was scheduled for treatment and following are the before, during and after images. Treatment ended in Summer of 2012 and patient was recently seen for follow up and did not show any relapse.

Pre-treatment

Mid treatment 6 months treatment with

Tandem appliance

Phase 2 braces and CS 2000

Completion of treatment in 2012

Cephalometric comparisons from start to finish

Discussion:

This case report describes the non-surgical intervention and treatment of a skeletal Class III mal-occlusion. With the advancements in today's dental technology and treatment procedures, surgical intervention should not be the first resort for treatment. As this case shows normal skeletal base relationships and normal occlusion can be achieved in a less invasive procedure and non-surgically.

In conclusion, I am not advocating that surgery should not be an option, but it is imperative to seek multiple opinions before a final decision for treatment is decided upon.

The author:

My name is Ramin Mehregan D.M.D. I graduated in 1992 from Boston University School of Graduate Dentistry. In 1999 I started my training with Dr. Clayton Chan (www.occlusionconnections.com) in the field of Gneuromuscular Dentistry which focuses in the treatment of TMJD disorders and full mouth rehabilitation. Upon completion of my training I continued my training in the field of orthodontics/orthopedics. Gneuromuscular Occlusion/Dentistry combines the application of sound gnathologic occlusal mechanics of occlusion with scientific and physiologic principles of NMD (Neuro-muscular-dentistry) in a balanced manner. Gneuromuscular is a discipline of dentistry that is now being recognized as key to comprehensive TMD, restorative and orthodontic dentistry that has been the missing link in our dental society.