Every patient has a malocclusion to some degree. Teeth are not set in stone. There is a dynamic relationship between tooth position, arch shape and mandibular posture. When the pathologic position exceeds our accommodative capacity, patients begin to complain either of pain, discomfort, or esthetics. We all have the ability to exist in an accommodative pathologic position.
My goal is to give you an insight into environmental influences on the development of malocclusion, and reconstruction failures. To intercept and develop a treatment plan we should begin immediately post partum and continue evaluating our patients throughout life. Every dentist has watched patients develop Class I, Class II, Div 1 or 2, and Class III malocclusions.
The fetus swallows from about 12 weeks of gestation, so for 28 weeks the gustatory system is exposed to chemicals in the amniotic fluid. Chemicals in the amniotic fluid include glucose, fructose, lactic acid, pyruvic and citric acids, fatty acids, phospholipids, creatinine, urea, uric acids, polypeptides, proteins and salts. There are gradual short term changes in the amniotic fluid compositions due to the fetus urinating into the fluid. The volume ranges from 173 to 677 ml/ day. In the last third of gestation the fetus swallows large volumes of amniotic fluid, ranging from 200 to 760 ml/ day.
- Barsh, L.I.:he Origin of Pharyngeal Obstruction During Sleep: Sleep and Breathing, 1999, 3:17-21
The upper airway anatomy of the human newborn approximates the anatomy of primates. There is a close approximation and locking of the uvula and epiglottis which allows for simultaneous sucking of milk and breathing. The tongue remains entirely within the oral cavity eliminating the oropharynx.
For the first 6 months of life, an infant is an obligate nose breather as a result of contact between the epiglottis and soft palate at birth.
Contact between the epiglottis and the soft palate at birth provides a channel from the external nares through the nasal cavities, nasal pharynx, larynx, and trachea into the lungs. Food passes on either side of the inter locked larynx into the esophagus through the isthmus faucium without interfering with the patent airway.
During the first approximately 18 months full term post partum, the laryngeal complex migrates from its original subcranial position to lie opposite the 5th cervical vertebra eliminating the interdigitation between the soft palate and epiglottis developing an oropharynx.
Mouth breathing occurs when nasal airway flow is diminished. This usually occurs when goblets cells within the nasal passages react to allergen producing inspissated (thick) secretions. The thick secretion reduces cilia locomotion resulting in bacterial stagnation within the nasal passages.
Primary Origins of Oral Habits
- Instinct (unlearned sucking reflex)
- Bottle feeding instead of breast feeding
- Not fatiguing the sucking reflex
- Upper airway obstruction
Secondary results: sucking becomes a satisfying habit like smoking and is evident when the infant or child is angry, hungry, tired (tranquilizing effect), frightened, in pain or discomfort and can result from imitation.
- A.The head of an infant is approximately one-quarter of his/ her total height.
- B. Whereas the head of an adult is one-eighth of his/ her total height.
- C. The portion of leg length to total stature in infants is approximately 35% of total height.
- D. Whereas in adults it increases to 50%. This phenomenon is known as differential growth.
Dr. Garry recognized the importance of facial profiles and proportions long before it was noted in today’s dental arena.
Optimal nasolabial line angle for optimal airway and esthetics is 90 degrees to 110 degrees. (The following are pictures of Dr. James F. Garry himself over a period of time).
The following is one of Dr. Garry’s TMD patients who he treated with a lower removable orthotic using J3 Myomonitor TENs.
Another patient treated by Dr. Garry showing the improved lower one third of the face.
Dr. Jim recognized early on facial proportions were a natural result when following the neuromuscular principles of occlusion. Long before the advent of promoting golden proportions of the face, tooth and cranial to mandibular proportional relationships as advocated by today’s younger dentists and dental continuing educational institutions, Dr. Jim taught and acknowledged that these proportional ratio’s existed in nature.
Severe overjet and overbite developed when the monkey lowered the mandible and maintained the tongue in a more retruded position. In the course of the experiment the shape of the relaxed tongue slowly changed. The histologic sections show healthy muscles fibers in a deviant orientation.
Stimulation of the posterior part of the tongue made it narrow and pointed, resulting in an open bite and a narrowing of the mandibular dental arch.
Continuous retraction of the tip of the tongue made it short and bulky, which in turn created a wider mandibular dental arch with extruded incisors.
The Tongue Maintains the Dental Arch
After the tongue in the rhesus monkey had been reduced, several months elapsed before the position of the teeth adjusted to the new stimuli from the tongue.
The reduction of the tongue caused a corresponding reduction of the dental arches, steeper inclination of the incisors, and a deeper bite.
An open bite developed when the tongue assumed a more anterior position.
Special Note: Distributing and use of any of these photos to other websites or presentations is considered stealing intellectual property. No permission is granted to anyone accept Dr. Clayton A. Chan who was granted permission directly by Dr. James F. Garry’s son Ron. The originator and author of these images is shared on this site in honor of Dr. Jim to preserve his legacy and a means to encourage other TMJ pain sufferers and dentists hope and better understanding from this site. Copyright permission was given only to Dr. Clayton A. Chan for use on the Occlusion Connections website and no others. Please respect the rights and privacy of Dr. James F. Garry and family members.
Copyright © 2016 Occlusion Connections™ All rights reserved.
About Dr. James F. Garry:
- Dr. James F. Garry – BiographyDr. James F. Garry – Biography
- “In Loving Memory of My Great Mentor and Dear Friend, Dr. James F. Garry.”
- Airway Obstruction: Environmental Influences
- Upper Airway Obstruction and Upper Airway Deformaties – Part 1
- Upper Airway Obstruction and Upper Airway Deformaties – Part 2
- Upper Airway Obstruction and Upper Airway Deformaties – Part 3
Copyright © 2016 Occlusion Connections™ All rights reserved.