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The Need for Face Bows
COMMENTARIES
LETTERS
J
ADA welcomes letters from readers on articles that have appeared in The Journal. The Journal reserves the right to edit all communications and requires that all letters be signed. Letters must be no more than 550 words and must cite no more than five references. No illustrations will be accepted. A letter concerning a recent JADA article will have the best chance of acceptance if it is received within two months of the article’s publication. For instance, a letter about an article that appeared in April JADA usually will be considered for acceptance only until the end of June. Letters regarding articles published online ahead of print will be published after the article appears in print if the letter is selected for publication. You may submit your letter via e-mail to [email protected]; by fax to 1-312-440-3538; or by mail to 211 E. Chicago Ave., Chicago, IL. 60611-2678. By sending a letter to the editor, the author acknowledges and agrees that the letter and all rights of the author in the letter sent become the property of The Journal. Letter writers are asked to disclose any personal or professional affiliations or conflicts of interest that readers may wish to take into consideration in assessing their stated opinions. The views expressed are those of the letter writer and do not necessarily reflect the opinion or official policy of the Association. Brevity is appreciated.
WELL-FUNCTIONING OFFICES
I have quite a different view from that of Dr. Levin in his June A Better Practice column, “Reach Practice Potential With New Systems” (Levin RP. JADA. 2016;147[6]:460-461), of how to grow an already busy practice that is not terribly profitable and, from the letter writer’s description, is not a very joyous place to work. To extrapolate, it must also not be a very joyous office for his or her patients as well. The trick, I believe, is to link them: happy staff and satisfied patients. Of course, well-functioning systems are essential and include all of the things on Dr. Levin’s list. I would prioritize them a bit differently and place staff member meetings and morning meetings at the top of my list. The reason is that it is at these meetings, run well and according to a wellsocialized and accepted format, the culture of the office is displayed, treatment plans are discussed, and staff members are socialized. Because of that, the brand of the office is reinforced. Brand you say. What does that mean? A dental office is a dental office, and it is either well functioning or not. I disagree. The brand is a fundamental feature of our office; it is
696 JADA 147(9) http://jada.ada.org
the DNA, so to speak, and, in the absence of the staff members understanding the office culture (the office DNA), patients will experience a lack of harmony. And guess what? Patients will feel less comfortable and be much less likely to accept the treatment plans they are given. So that is my connection. Harmony among the staff members, including and especially with the dentist, will mean more trust, and only good things will follow. Systems sure. But people first. Alan Goldstein, DMD Certified Life Coach The Coaching Practice New York, NY
http://dx.doi.org/10.1016/j.adaj.2016.07.003 Copyright ª 2016 American Dental Association. All rights reserved.
He postulates that employee communication (“staff member meetings and morning meetings”) takes precedence in such a situation, whereas I emphasize that scheduling is the proper system to start with. And maybe we’re both right. A practice struggling with growth can have daily staff member meetings for years and still struggle with growth. Meetings by themselves do not ensure that problems are addressed or resolved. On the other hand, a practice cannot successfully implement a new scheduling system without the dentist communicating the particulars and the rationale to team members, who will be the ones—for the most part— putting the new protocols in place. What it comes down to is this. There are 2 kinds of what I would term “macrosystems”: employee systems (such as communication) and patient systems (such as scheduling). Dentists need both kinds of systems working together to generate positive results in terms of team member morale, efficiency, and growth. I appreciate Dr. Goldstein’s feedback. Dentistry is a profession that continues to move forward—from both clinical and practice management standpoints—based on the diverse insights, experiences, and contributions of its members. Roger P. Levin, DDS Founder and Chief Executive Officer Levin Group Owings Mills, Maryland
http://dx.doi.org/10.1016/j.adaj.2016.07.004 Copyright ª 2016 American Dental Association. All rights reserved.
THE NEED FOR FACE BOWS
Author’s response: I thank Dr. Goldstein for his thoughtful comments on my article. We are in agreement that “well-functioning systems are essential,” as he says in his letter. However, on the question of what system should be addressed first in a low-production practice, we each have a different opinion.
September 2016
I read Dr. Yohn’s June JADA article “The Face Bow Is Irrelevant for Making Prostheses and Planning Orthognathic Surgery,” (Yohn K. JADA. 2016;147[6]:421-426) and could not help but envision the late great Dr. Sigurd Ramfjord, legendary University of Michigan professor of dental occlusion (where Dr. Yohn is on the
COMMENTARIES
faculty), rolling over in his grave. Dr. Ramfjord scientifically described the importance of harmony between joints, muscles, and occlusion. He and Dr. Ash stated, “The goal of all occlusal therapy is a peaceful neuromusculature.”1 Achieving this goal requires precise study of the proper joint position on closure. The studies of the dental anatomist Dr. Harry Sicher clearly showed that joints are always seated by the muscles that pull across them.2 Elevator muscles fully seat the temporomandibular joints on closure. This position should be recorded to study the physiological hinge of the mandible. This recording is accomplished using a face bow and bite record. If this position is ignored or considered irrelevant, the clinician risks significant error and disruption of neuromuscular harmony. Drs. Charles Gibbs and Harry Lundeen conducted landmark studies on the function of teeth.3 Their work with several hundred participants, using a gnathic replicator, demonstrated that the end point of normal jaw closure is not maximum intercuspation of the teeth (Dr. Yohn’s centric occlusion) but centric relation (CR), which is the fully seated temporomandibular joints. This is the starting point for evaluating dental occlusion for prosthetic predictability. The most accurate, predictable, and thus cost-effective method of analysis is the use of a semiadjustable articulator, CR record, and face bow transfer. Having worked for the past 34 years in partnership with Dr. Peter Dawson in a practice in which we have predictably restored thousands of occlusions, we would not attempt to analyze an occlusion without the use of diagnostic study models mounted in CR with a face bow transfer. Reading Dr. Yohn’s article and the perspective presented causes the concern that it represents a bias based on very selective literature and clinical inexperience, rather than sound science applied to predictably resolve masticatory system problems and produce comfortable and stable joints,
muscles, and occlusions by using a most relevant tool, the face bow. DeWitt C. Wilkerson, DMD Director of Dental Medicine The Dawson Academy St. Petersburg, FL and Past President American Equilibration Society Chicago, IL and Vice President American Academy for Oral Systemic Health St. Petersburg, FL
http://dx.doi.org/10.1016/j.adaj.2016.07.005 Copyright ª 2016 American Dental Association. All rights reserved.
1. Ash MM Jr., Ramfjord SP. Occlusion. 4th ed. Philadelphia, PA: Saunders; 1995. 2. Sicher H. The temporomandibular joint. In: Sarnat BG, ed. The Temporomandibular Joint: A Biological Basis for Clinical Practice. 2nd ed. Springfield, IL: Thomas; 1964. 3. Gibbs C, Lundeen HC. The Function of Teeth: The Physiology of Mandibular Function Related to Occlusal Form and Esthetics. Gainesville, FL: L and G; 2005.
MORE ON FACE BOWS
It was disappointing to see an article in June JADA that is detrimental to treatment outcomes for patients needing prostheses or orthognathic surgery (Yohn K. “The Face Bow Is Irrelevant for Making Prostheses and Planning Orthognathic Surgery.” JADA. 2016;147[6]:421-426). A face bow is an important step in analysis of occlusal problems as well as a key factor in determining treatment plans that produce predictable prosthetic and restorative results. If the goal is to develop an occlusion that is in harmony with the temporomandibular joints (TMJs) and the neuromuscular system, the analysis must start with the correct position and condition of the TMJs. The author, however, does not recognize some of the important factors that relate to a harmonious occlusion and a peaceful neuromusculature. His premise is based on several misconceptions that need to be exposed, because the implications have consequences that go far beyond just the face bow misconstrual.
The first misconception is that “. pure rotation of the condyles during functional activity is a myth.” What is missed in this conclusion is the fact that it is impossible to open and close the jaw without some rotation of the condylar axis. The goal of recording the axis at the terminal hinge position of centric relation (CR) must not be misconstrued as limiting the condylar rotation to CR. The condyles can and do rotate, as the jaw is capable of opening and closing throughout the full range of function from CR through complete protrusive movement. However, the condylar axis position that is critical is the completely seated position that occurs when coordinated muscle function is allowed to seat the condyles without interference from deflective tooth inclines during complete closure to maximum intercuspal position (MIP). If the teeth interfere with this CR condyle position, requiring displacement of the TMJs to achieve MIP, the result is an incoordinated, hyperactive neuromusculature, a fact that is confirmed by numerous electromyogram recordings. Recording the bite without reference to the position of the TMJ axis (as advocated in Dr. Yohn’s article) will always result in a record of a displaced TMJ if there are deflective occlusal interferences present. The author states that a face bow “[i]s transferring an artificial rotational axis of the condyles in the mandibular fossa (produced by the dentist) . .” There is nothing “artificial” about the anatomical location of a correct condylar axis. The reason a face bow record of the condylar axis is important is related to the clarification of another misconception in this article. That is the misconception that the masticatory muscles act independently of exquisite sensory input from the teeth without regard to the effects of deflective interferences that cause disharmony between the occlusion and the completely seated joint
JADA 147(9) http://jada.ada.org
September 2016 697
LETTERS
J
ADA welcomes letters from readers on articles that have appeared in The Journal. The Journal reserves the right to edit all communications and requires that all letters be signed. Letters must be no more than 550 words and must cite no more than five references. No illustrations will be accepted. A letter concerning a recent JADA article will have the best chance of acceptance if it is received within two months of the article’s publication. For instance, a letter about an article that appeared in April JADA usually will be considered for acceptance only until the end of June. Letters regarding articles published online ahead of print will be published after the article appears in print if the letter is selected for publication. You may submit your letter via e-mail to [email protected]; by fax to 1-312-440-3538; or by mail to 211 E. Chicago Ave., Chicago, IL. 60611-2678. By sending a letter to the editor, the author acknowledges and agrees that the letter and all rights of the author in the letter sent become the property of The Journal. Letter writers are asked to disclose any personal or professional affiliations or conflicts of interest that readers may wish to take into consideration in assessing their stated opinions. The views expressed are those of the letter writer and do not necessarily reflect the opinion or official policy of the Association. Brevity is appreciated.
WELL-FUNCTIONING OFFICES
I have quite a different view from that of Dr. Levin in his June A Better Practice column, “Reach Practice Potential With New Systems” (Levin RP. JADA. 2016;147[6]:460-461), of how to grow an already busy practice that is not terribly profitable and, from the letter writer’s description, is not a very joyous place to work. To extrapolate, it must also not be a very joyous office for his or her patients as well. The trick, I believe, is to link them: happy staff and satisfied patients. Of course, well-functioning systems are essential and include all of the things on Dr. Levin’s list. I would prioritize them a bit differently and place staff member meetings and morning meetings at the top of my list. The reason is that it is at these meetings, run well and according to a wellsocialized and accepted format, the culture of the office is displayed, treatment plans are discussed, and staff members are socialized. Because of that, the brand of the office is reinforced. Brand you say. What does that mean? A dental office is a dental office, and it is either well functioning or not. I disagree. The brand is a fundamental feature of our office; it is
696 JADA 147(9) http://jada.ada.org
the DNA, so to speak, and, in the absence of the staff members understanding the office culture (the office DNA), patients will experience a lack of harmony. And guess what? Patients will feel less comfortable and be much less likely to accept the treatment plans they are given. So that is my connection. Harmony among the staff members, including and especially with the dentist, will mean more trust, and only good things will follow. Systems sure. But people first. Alan Goldstein, DMD Certified Life Coach The Coaching Practice New York, NY
http://dx.doi.org/10.1016/j.adaj.2016.07.003 Copyright ª 2016 American Dental Association. All rights reserved.
He postulates that employee communication (“staff member meetings and morning meetings”) takes precedence in such a situation, whereas I emphasize that scheduling is the proper system to start with. And maybe we’re both right. A practice struggling with growth can have daily staff member meetings for years and still struggle with growth. Meetings by themselves do not ensure that problems are addressed or resolved. On the other hand, a practice cannot successfully implement a new scheduling system without the dentist communicating the particulars and the rationale to team members, who will be the ones—for the most part— putting the new protocols in place. What it comes down to is this. There are 2 kinds of what I would term “macrosystems”: employee systems (such as communication) and patient systems (such as scheduling). Dentists need both kinds of systems working together to generate positive results in terms of team member morale, efficiency, and growth. I appreciate Dr. Goldstein’s feedback. Dentistry is a profession that continues to move forward—from both clinical and practice management standpoints—based on the diverse insights, experiences, and contributions of its members. Roger P. Levin, DDS Founder and Chief Executive Officer Levin Group Owings Mills, Maryland
http://dx.doi.org/10.1016/j.adaj.2016.07.004 Copyright ª 2016 American Dental Association. All rights reserved.
THE NEED FOR FACE BOWS
Author’s response: I thank Dr. Goldstein for his thoughtful comments on my article. We are in agreement that “well-functioning systems are essential,” as he says in his letter. However, on the question of what system should be addressed first in a low-production practice, we each have a different opinion.
September 2016
I read Dr. Yohn’s June JADA article “The Face Bow Is Irrelevant for Making Prostheses and Planning Orthognathic Surgery,” (Yohn K. JADA. 2016;147[6]:421-426) and could not help but envision the late great Dr. Sigurd Ramfjord, legendary University of Michigan professor of dental occlusion (where Dr. Yohn is on the
COMMENTARIES
faculty), rolling over in his grave. Dr. Ramfjord scientifically described the importance of harmony between joints, muscles, and occlusion. He and Dr. Ash stated, “The goal of all occlusal therapy is a peaceful neuromusculature.”1 Achieving this goal requires precise study of the proper joint position on closure. The studies of the dental anatomist Dr. Harry Sicher clearly showed that joints are always seated by the muscles that pull across them.2 Elevator muscles fully seat the temporomandibular joints on closure. This position should be recorded to study the physiological hinge of the mandible. This recording is accomplished using a face bow and bite record. If this position is ignored or considered irrelevant, the clinician risks significant error and disruption of neuromuscular harmony. Drs. Charles Gibbs and Harry Lundeen conducted landmark studies on the function of teeth.3 Their work with several hundred participants, using a gnathic replicator, demonstrated that the end point of normal jaw closure is not maximum intercuspation of the teeth (Dr. Yohn’s centric occlusion) but centric relation (CR), which is the fully seated temporomandibular joints. This is the starting point for evaluating dental occlusion for prosthetic predictability. The most accurate, predictable, and thus cost-effective method of analysis is the use of a semiadjustable articulator, CR record, and face bow transfer. Having worked for the past 34 years in partnership with Dr. Peter Dawson in a practice in which we have predictably restored thousands of occlusions, we would not attempt to analyze an occlusion without the use of diagnostic study models mounted in CR with a face bow transfer. Reading Dr. Yohn’s article and the perspective presented causes the concern that it represents a bias based on very selective literature and clinical inexperience, rather than sound science applied to predictably resolve masticatory system problems and produce comfortable and stable joints,
muscles, and occlusions by using a most relevant tool, the face bow. DeWitt C. Wilkerson, DMD Director of Dental Medicine The Dawson Academy St. Petersburg, FL and Past President American Equilibration Society Chicago, IL and Vice President American Academy for Oral Systemic Health St. Petersburg, FL
http://dx.doi.org/10.1016/j.adaj.2016.07.005 Copyright ª 2016 American Dental Association. All rights reserved.
1. Ash MM Jr., Ramfjord SP. Occlusion. 4th ed. Philadelphia, PA: Saunders; 1995. 2. Sicher H. The temporomandibular joint. In: Sarnat BG, ed. The Temporomandibular Joint: A Biological Basis for Clinical Practice. 2nd ed. Springfield, IL: Thomas; 1964. 3. Gibbs C, Lundeen HC. The Function of Teeth: The Physiology of Mandibular Function Related to Occlusal Form and Esthetics. Gainesville, FL: L and G; 2005.
MORE ON FACE BOWS
It was disappointing to see an article in June JADA that is detrimental to treatment outcomes for patients needing prostheses or orthognathic surgery (Yohn K. “The Face Bow Is Irrelevant for Making Prostheses and Planning Orthognathic Surgery.” JADA. 2016;147[6]:421-426). A face bow is an important step in analysis of occlusal problems as well as a key factor in determining treatment plans that produce predictable prosthetic and restorative results. If the goal is to develop an occlusion that is in harmony with the temporomandibular joints (TMJs) and the neuromuscular system, the analysis must start with the correct position and condition of the TMJs. The author, however, does not recognize some of the important factors that relate to a harmonious occlusion and a peaceful neuromusculature. His premise is based on several misconceptions that need to be exposed, because the implications have consequences that go far beyond just the face bow misconstrual.
The first misconception is that “. pure rotation of the condyles during functional activity is a myth.” What is missed in this conclusion is the fact that it is impossible to open and close the jaw without some rotation of the condylar axis. The goal of recording the axis at the terminal hinge position of centric relation (CR) must not be misconstrued as limiting the condylar rotation to CR. The condyles can and do rotate, as the jaw is capable of opening and closing throughout the full range of function from CR through complete protrusive movement. However, the condylar axis position that is critical is the completely seated position that occurs when coordinated muscle function is allowed to seat the condyles without interference from deflective tooth inclines during complete closure to maximum intercuspal position (MIP). If the teeth interfere with this CR condyle position, requiring displacement of the TMJs to achieve MIP, the result is an incoordinated, hyperactive neuromusculature, a fact that is confirmed by numerous electromyogram recordings. Recording the bite without reference to the position of the TMJ axis (as advocated in Dr. Yohn’s article) will always result in a record of a displaced TMJ if there are deflective occlusal interferences present. The author states that a face bow “[i]s transferring an artificial rotational axis of the condyles in the mandibular fossa (produced by the dentist) . .” There is nothing “artificial” about the anatomical location of a correct condylar axis. The reason a face bow record of the condylar axis is important is related to the clarification of another misconception in this article. That is the misconception that the masticatory muscles act independently of exquisite sensory input from the teeth without regard to the effects of deflective interferences that cause disharmony between the occlusion and the completely seated joint
JADA 147(9) http://jada.ada.org
September 2016 697