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By Clayton A. Chan, D.D.S.
Founder and Director of OCCLUSION CONNECTIONS™, Las Vegas, Nevada, U.S.A.

“The main thing is to keep the main thing the main thing.” - Steven Covey

Every neuromuscularly trained and treating clinician should recognize, practice and  implement the following five principles in their dental practice.  These are fundamental keys to every level of TMD, orthodontic and comprehensive restorative dentistry.  Failure to acknowledge these keys principles will result in misdiagnosis and mistreatment. At Occlusion Connections we encourage all to grasp these concepts in order that an optimal level of dentistry can be performed by the dentist and appreciated by the patient.

Doctors who have received training at Occlusion Connections have recognized these principles to be fundamentally important distinguishing their dental practice with this kind of neuromuscular thinking from standard neuromuscular dentistry thinking.

To learn more about Occlusion Connections Advanced Dentist training program read more at: OC’s Post Graduate Dental Education and Training

© 2009 Clayton A. Chan, DDS. All Rights Reserved.

The Leader in Neuromuscular Dentistry

Filed under: Bite Optimization, CHAN Optimized Bite™, Diagnosis and Neuromuscular Treatment, Full Mouth Reconstruction, NMD Education and Training, Neuromuscular Dentistry, Neuromuscular Education and Training, Neuromuscular Technology, Occlusion, Optimized Bite, Optimized Bite™, Restorative Dentistry, TENS, TMJ, TMJ and Neuromuscular Dentistry, Uncategorized by Clayton A. Chan, D.D.S.
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Evaluating the Cervical Spine and Head

By Clayton A. Chan, D.D.S.

The antero-posterior (AP) posture of the head in relation to the cervical spine can be determined by a vertical plumb line from head down to the dorsal portion of the thoracic spine. (Most restorative, orthodontic and TMD dentist don’t pay attention to this aspect of head posture). Garry has reported measuring the neck curvature using a plumb line to the deepest curvature of the posterior of the cervical neck region to determine the distance and degree of forward head posture.(1)   Optimal distance according to Racabado is 6 cm.(3, 4)

Racabado further defined normal cervical lordosis and normal craniovertebral relationships based on cephalometric measurements. A line that connects the posterior nasal spine to the basi-occiput is called the McGregor’s plane. The odontoid plane (OP) is a line that extends from apex to the anterior inferior angle of the odontoid process.  A normal measurement of the posterior-inferior angle at the intersection of McGregor’s plane and OP is 101 degrees +/- 5 degrees (96-106 degrees). A distance between the basi-occiput to the posterior arch of the atlas is 4-9 mm (less than 4 mm indicates cranio-vertebral compression).(3, 5)

For more information and details read more: Chan, C.A.: Evaluating the Cervical Spine and Head, page 15-19.

Finding the Occlusal Plane

Many clinicians abroad have determined and confirmed that the occlusal plane has a great influence on the functional articulation and esthetic aspects of stomatognathic system.  Clinicians have recognized that the occlusal plane should be at a right angle to the occlusal forces for stability of the occlusion, head and neck musculature; perpendicular to the long axis of occlusal forces produced by an optimal cervical posture and an optimized mandibular closing trajectory (path).  Many neuromuscular minded dentist have falsely been misled to believe that the occlusal plane is flat or parallel relative to horizontal level.  This is in fact a wrong teaching that defies natures bio-physiologic and anatomical design for health.

Note: Hand held diagnostic model casts oriented into a maximum intercuspal position is not sufficient to establish natures “true” occlusal plane orientation. Determining a physiologic dimensional relationship of the upper to lower model casts (vertical, antero-posterior, frontal, pitch, yaw and roll) is crucial if one desires to minimize mandibular to maxillary jaw torque during function. Reproducing nature’s occlusal plane orientation with the model casts using the Modified Fox Plane technique per Chan assists the dentist and lab to replicate what is in the patients mouth.  Read more: “Mounting the Diagnostic Case Using the Fox Plane”.

The inclination of the occlusal plane (IOP) is one of the key factors governing occlusal balance. (6)  Determination of inclination of the occlusal plane is an important step before construction of full arch restorative and full denture type cases. Evaluating and assessing the bilateral occlusal plane of the maxillary arch for symmetry, balance and form is desirable to meet the demands of function and appearance.  Anteroposterior IOP is typically determined with a device called the Fox occlusal plane, (7)  which is commonly positioned parallel to Camper’s plane or can be used to capture the occlusal plane slope by orienting the Fox plane (modified according to Chan) parallel to the horizontal level (the floor) and patient’s head positioned at level using bite recording material.(8)     Ear bows or face bows have been traditionally been used in the gnathologic arena to register the steepness and tilt of the occlusal plane using the auditory meatus, nasion and orbitale as reference points.

Note: Radiographic images of before restorative treatment, progress (stabilized mandible at optimized mandibular position) and after (finished restored occlusal plane at optimized mandibular position). All images were recorded with the patient’s head position (“unposed” purposely – not at Frankfurt plane) to determine how the mandibular occlusal positioning can effect the occlusal plane and head posture. Initial radiographic shows a flatter occlusal plane relative to horizontal level (red line), patient’s head is slightly tilted upward with neck strain. As the patient is stabilized with an improved gneuromuscular occlusal position the head and cervical/neck also changes orientation relative to horizontal level. Patient’s neck pain is resolved using a lower fixed bonded orthotic over the existing restorative dentistry.  Final imaging shows improved occlusal plane (angled relative to horizontal level.  Patient no longer complains of neck and shoulder pain. To read more about this case and  “What Angle is the Occlusal Plane Relative to Horizon”

Flat Maxillary Cast Mountings

Maxillary cast mounting and orientation is critical in phase II diagnosis and treatment.  Maxillary cast that are mounted in a manner that depicts a flat to upward slope anteriorly (e.g. classic HIP – hamular notch, incisive foramen, flat mount) often times will unknowingly build in pathologic vector of forces due to an abnormal occlusal plane orientation.

• This will lead to toothy looking smiles, especially in the second bicuspid molar region and will also result in vertically taller mandibular posterior clinical crowns.
• A curve of Spee is often compromised and minimal due to inadequate space between the desired occlusal plane and tooth preparation during laboratory waxing and crown fabrication.
• To compensate for this the clinician will need to be more aggressive in maxillary posterior occlusal prep reduction which can lead to pulpal infringement and endodontic therapy.
• Skewed crown to root ratio in both the upper and lower arches will be present making arch and crown form lacking in natures anatomic proportions.

Downward Sloping Maxillary Cast Mounting

Maxillary cast mountings that show a natural downward sloping occlusal plane incline (e.g. modified Fox plane level mount according to C. A. Chan) allows for balanced vector of muscular and occlusal forces due to a more physiologic plane orientation that matches an optimized cervical, head and craniomandibular posture.

• Softer natural smile line leads to a more pleasing esthetic smile.
• Less posterior occlusal prep reduction in either maxillary or mandibular arches is required.
• Easy to develop a curve of Spee.
• Crown to root ratio tends to be closer to natures golden proportions.

References:

1. Garry, JF: Upper Airway Compromise and Musculo-skeletal Dysfunction of the Head and Neck (MSD), 1977.
2. Yee, D: Weight of the human head.  Department of Anatomy and Histology, University of Sydney, Australia. danny.oz.au/anthropology/notes/human-head-weight.html. December 13, 2006.
3. Tilley, L and Hickman, DM: TMD-An Upper Quarter Condition. Anthology of ICCMO. Vol. V. 1995.
4. Racabado, M: Physical Therapy and Dentistry: An Overview, J of Craniomandibular Practice, 1982; Vol. 1, pp46-49.
5. Racabado M: Dentistry I. Racabado Institute for Carniomandibular and Vertebral Therapeutics, Atlanta: Institute of Graduate Health Sciences, 1984.
6. Ogawa T, et al.:  Inclination of the occlusal plane and occlusal guidance as contributing factors in mastication. J Dent. 1998 Nov;26(8):641-7.
7. Trubyte (Fox) Occlusal Plane Plate: Dentsply International, Trubyte, Occlusal Fox Plane Item #92232, (800) 877-0020.
8. Chan, CA: Architecting the Occlusal Plane. Aurum Ceramic Continuum. Vol. 10, Issue 2, May 2006.

© 2009 Clayton A. Chan, DDS. All Rights Reserved.

Neuromuscular Dentistry

Filed under: Fox Occlusal Plane, Full Mouth Reconstruction, HIP Plane, NMD Education and Training, Neuromuscular Dentistry, Occlusion, Optimized Bite, Optimized Bite™, TMJ by Clayton A. Chan, D.D.S.
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by Clayton A. Chan,  D.D.S., M.I.C.C.M.O.

There are 4 main categories of dysfunctional mal occlusions that requires special attention when designing and managing the lower removable orthosis in the treatment of the TMD suffering patient.

The correction of malformations of the jaws and skeletal structures involving the masticatory system is especially important when attempting to preserve as well as restore optimal function of the skeletal system, its articulations and associated structures, including the trigeminal system.  Clinicians who treat these 4 main problematic types must recognize in the diagnostic phases what structural, biochemical and emotional factors are involved to effectively treat and resolve the various musculoskeletal occlusal symptoms.

Micro occlusal management of the orthosis (orthopedic jaw realignment device) and training is required of the TMJ dentist at the highest levels to properly address the proprioceptive occlusal signaling and communication that occurs with the TMD patient who experiences various levels of occlusal awareness and at the same time present with cervical dysfunction, TMJ primary disorders, Class II Division 2 dental mal alignments and or Anterior open bite problems.

Resolving any one of these or a combination of these problems can challenged the TMJ treating clinician if they are not familiar with sound protocols.  The following is a general guide as to what work up and protocols may be necessary in addressing the needs of the dysfunctional TMJ/TMD patient.

Optimized Bite
When I mention “Apply gnathological principles when managing the Optimized bite” I am referring to the detailed proprioceptive mechanics that the trained dentist must pay attention to during all jaw movements.  Based on a sound Optimized Bite position (GNM) which can only be best achieved with jaw tracking technology and TENS combined gives the  best results.  Using just the Myomonitor TENS alone is not sufficient even in the best of trained clinicians since visual observations alone can not obtain consistency in precision and objective reliablity when attempting to establish a starting lower to upper jaw relationship.  This is crucial if success is desired.

Additional adjunctive support maybe required within the medical and dental community to obtain a successful resolution. Establishing an Optimal physiologic mandibular position is critical to TMJ therapy. Micro occlusal management is of key importance of the TMJ pain patient is going to experience a calming of the muscles since it is clearly recognized within the TMD community that occlusion can effect the masticatory muscles responses either positively or negatively.

When there are are subtle occlusal imbalances in the bite which can contribute to jaw torque, the muscles of the jaw, head, neck and shoulders can strain and cause severe pain, further disrupting the central nervous system.

Read more: Four Types  of Neuromuscular Dysfunctional TMJ Challenges

Neuromuscular Dentistry

Filed under: Diagnosis and Neuromuscular Treatment, Neuromuscular Dentistry, Neuromuscular Education and Training, Occlusion, TENS, TMJ, TMJ Pain, TMJ Treatment, TMJ and Neuromuscular Dentistry, Uncategorized by Clayton A. Chan, D.D.S.
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