Understanding Vertical Bite Problems
Your vertical bite dimension — how much space exists between your upper and lower front teeth when they meet — determines whether you have normal bite, deep bite, or open bite. Several measurements matter: how tall your face is (front to back), where your jaw angles, and crucially, how much your upper teeth overlap your lower teeth (overbite, normal is 2-3 millimeters).
Your jaw's growth angle determines your bite tendency. High-angle people (mandible comes in at a steep angle, like a bird's beak) tend toward open bite — their vertical dimensions naturally increase, leaving front teeth not touching. These people have 1.5-2.5 times higher open bite risk.
Low-angle people (mandible comes in more horizontal, like a bulldog) trend toward deep bite — their vertical dimensions are compressed, causing excessive overlap. These people show 40-50% increased deep bite prevalence.
Open bite (anterior open bite, or AOB) affects 5-10% of people overall, though 10-20% of children have it (many resolve naturally). Serious open bites (over 4 millimeters of space between front teeth) affect 3-5% and create real problems: lisps from airflow escaping, impossible front-tooth chewing, and unattractive open-mouth appearance. Deep bite (over 5 millimeters overlap) affects 8-15% of people, causing front-tooth wear 40-50% faster than normal.
What Causes Open Bite?
Thumb-sucking is the classic culprit in children. The sucking habit prevents front teeth from erupting (coming in normally), the tongue thrusts forward to fill the gap, and the whole problem perpetuates. Open bite typically starts when kids begin sucking (ages 2-4). If the habit stops by age 7-8, about 60-70% of cases close spontaneously within 6-12 months as teeth erupt normally. But if sucking continues beyond age 10, only 30-40% close spontaneously — the jaw growth pattern has become entrenched.
Tongue thrust (abnormal swallowing where the tongue presses into front teeth instead of pressing the palate) perpetuates open bite once established. Even if sucking stops, tongue thrust keeps pushing teeth apart during every swallow. This requires speech therapy (tongue thrust exercises retraining swallowing patterns) combined with orthodontics — braces alone can't fix it if the tongue keeps pushing.
Mouth breathing (from enlarged adenoids, allergies, or habit) causes skeletal changes predisposing to open bite. Two or more years of mouth breathing increases vertical jaw dimensions 5-8 millimeters, tips the mandible forward, and increases facial height. Adenoid/tonsil enlargement affects 15-25% of children, causing mouth breathing and open bite. Removing enlarged adenoids/tonsils eliminates the mouth-breathing stimulus, preventing open bite perpetuation and allowing orthodontic correction to work.
Skeletal open bite (high-angle jaw pattern) is the most stubborn kind. These people's mandible naturally angles steeply, their vertical dimensions are naturally excessive, and teeth don't erupt far enough to meet. These cases need aggressive treatment: special growth-modifying appliances during childhood (if caught early), or surgical correction in adults, because braces alone can't fix the underlying jaw growth pattern.
What Causes Deep Bite?
Deep bite happens when opposite processes than open bite occur. Low-angle jaw patterns (mandible more horizontal, like a bulldog) naturally create deeper overlap. Back teeth don't erupt as much (lower eruption drive), while front teeth erupt more (compensating). Natural aging adds to it — your back teeth wear down 40-50 micrometers yearly over decades, reducing their height, which allows front teeth to overlap even more.
Deep bite creates multiple problems. Front teeth wear 40-50% faster because they bear excessive chewing forces that should be spread among all teeth. Lower front teeth sometimes dig into the roof of your mouth (gingival trauma occurs in 30-40% of severe deep bite cases), causing sore spots, receding gums, or tooth mobility.
Back teeth carry too much chewing stress while front teeth carry too little, making eating less efficient. Your jaw muscles work harder than necessary (increased TMJ stress). These problems justify treatment in 70-80% of deep bite cases — it's not purely cosmetic, it's functional.
Treatment Strategies for Vertical Problems
Fixing Open Bite
The first step is stopping the habit (if there is one). Stopping thumb-sucking in early childhood, with positive reinforcement and encouragement, leads to 60-70% of cases closing spontaneously within 6-12 months as teeth erupt normally. Speech therapy correcting tongue thrust (teaching proper swallowing) is essential for complete correction — without it, open bite tends to return.
Young children (ages 6-12) with open bite benefit from special growth-modifying appliances that position the lower jaw forward, provide space for front teeth to erupt, and encourage vertical growth backward. These appliances work 60-70% of the time, producing 3-6 millimeter improvement (enough to eliminate the open bite) over 12-18 months. Success requires catching it early, before the jaw growth pattern becomes too entrenched.
Older patients (adolescents and adults) with open bite need fixed braces combining special mechanics: moving back teeth up (intrusion, 150-250 gram forces, 6-12 months), allowing front teeth to move down and forward, and possibly distally positioning back molars. Modern braces achieve 3-4 millimeter vertical dimension closure in 8-12 months using mix mechanics.
Severe skeletal open bite (over 5 millimeters with high-angle jaw pattern) ultimately requires surgery. Your surgeon positions your upper jaw down and forward slightly while advancing your lower jaw, directly fixing the vertical dimension imbalance. Presurgical bracing (6-12 months), surgery, then postsurgical bracing (3-6 months) takes 12-18 months total but definitively corrects problems beyond braces' ability alone.
Fixing Deep Bite
Growing adolescents benefit most because back teeth naturally want to erupt. Your orthodontist simply guides that eruption with special elastics (vertical elastics from upper front to lower back) that pull back teeth down while allowing front teeth to move up. This leverage achieves 2-4 millimeters vertical dimension increase in 8-12 months.
For adults (non-growing patients), intrusion (moving front teeth up) becomes necessary. This requires heavy, continuous force (200-400 grams) for 6-12 months achieving 0.5-1.0 millimeter monthly movement upward. Root resorption (permanent root shortening) occurs in 30-40% of intrusion cases — an unavoidable risk. Modern orthodontists prefer combining some front tooth movement with whatever back tooth eruption is possible, minimizing intrusion duration and reducing root resorption risk.
Severe skeletal deep bite requires jaw surgery, typically maxilla (upper jaw) repositioning downward and forward, directly correcting the low-angle jaw pattern.
Stability After Correction
Open bite shows 15-25% relapse rate even with good retention — teeth tend to shift back toward the original open space partly because the underlying high-angle jaw pattern continues pushing vertically. Good retention (bonded wire plus removable retainers worn 3-5 nights weekly indefinitely) prevents most relapse, but some degree of reopening over years is realistic.
Deep bite shows better stability — about 95% stability with good retention and 6-month retention protocols. Skeletal changes stabilize better than dental changes. However, some relapse occurs over decades due to natural aging, wear, and continued jaw remodeling.
Myofunctional component (tongue thrust correction, mouth breathing elimination) is critical. Without addressing these habits, 40-60% of open bite relapse within 3 years. With proper myofunctional therapy combined with orthodontics, 15-25% relapse is more typical.
Successful vertical dimension correction requires precise diagnosis (dental versus skeletal), appropriate timing (growth phase is ideal for open bite; any age is fine for deep bite), and systematic mechanical application. Combined with myofunctional component management (habit elimination, tongue thrust correction), these full approaches achieve excellent long-term results with minimal relapse and maximum functional and esthetic benefit.
Vertical Dimension Assessment and Diagnosis
Cephalometric analysis quantifies vertical dimensions: mandibular plane angle (normal 21-30 degrees, high-angle patterns > 35 degrees, low-angle patterns < 20 degrees), anterior facial height (nasion-menton, normal 100-130 millimeters), vertical maxillary excess (normal 24-30 millimeters), overbite depth indicator (ratio comparing anterior overbite to vertical dimensions, normal ratio 0.37-0.42).
Clinical exam incorporates facial analysis: high-angle individuals show increased lower facial height, anterior vertical maxillary excess (showing excessive maxillary incisor visibility at rest), open mouth posture at rest, and often long narrow facial form. Low-angle individuals show decreased lower facial height, reduced maxillary incisor display, closed mouth posture, and often wide square facial form.
Vertical dimension classification (dental versus skeletal, primary etiology) guides treatment planning. Pure dental open bite (normal skeletal dimensions, anterior incisor non-eruption from habit or tooth positioning) responds to habit change and dental positioning. Skeletal open bite (high-angle pattern, excessive vertical maxillary dimensions) requires growth change or surgical treatment for definitive correction. Mixed patterns (most clinical cases, 70-80%) require combined approach addressing both dental and skeletal components.
Functional assessment determining centric relation (true jaw position free of muscular influences) versus centric occlusion (position of maximum intercuspation, often shifted from centric relation) requires careful exam. Anterior open bite only in centric occlusion (with anterior contact in centric relation) represents pseudo-open bite, responding well to occlusal equilibration or simple repairs repositioning jaw closure.
Treatment Duration and Stability Considerations
Anterior open bite correction requires 18-36 months for full treatment: early habit-change cases 12-18 months, adolescent growth-modified cases 18-24 months, surgical cases 12-18 months postsurgical completing. Severe skeletal cases with multiple etiologic factors require 24-36 months due to complex multidimensional correction.
Relapse represents significant open bite concern: dental-only correction shows 10-20% relapse (0.5-1.0 millimeter within 2 years); skeletal correction shows 2-5% relapse; orthodontically-corrected cases combined with untreated underlying skeletal high-angle pattern show 15-25% relapse. These relapse rates require indefinite retention (fixed lingual retainers, removable retainers 5 nights weekly indefinitely) preventing expensive re-treatment.
Deep bite shows superior stability: correction through posterior extrusion achieves 95%+ stability with 6-month retention protocols. Incisor intrusion shows 20-30% relapse even with extended retention. Growth completion (age 18-20+ years) and skeletal stability improvement reduces relapse 40-50% compared to adolescent treatment.
Myofunctional component elimination (tongue thrust correction, digit sucking cessation) critical to long-term stability. Untreated myofunctional problem produces 40-60% relapse within 3 years; treated cases achieve 15-25% relapse. Speech pathology coordination becomes essential for AOB cases, with documented 30-40% improved outcomes when coordinated myofunctional therapy accompanies orthodontia.
Long-Term Functional and Esthetic Outcomes
Successful anterior open bite correction restores anterior guidance function: incisors contact during protrusive movements, canines contact during lateral movements. This functional repair reduces posterior tooth stress 50-70% and eliminates anterior lisp in 80-90% of cases. Masticatory function improvement and speech normalization much enhance patient quality of life.
Deep bite correction eliminates anterior wear and gingival trauma: anterior wear cessation occurs right away post-correction, allowing 20-30 year treatment period extension before repair needs. Gingival trauma resolution prevents recession progression (30-40% of untreated deep bite demonstrate progressive recession, whereas corrected cases show stable gingival levels).
Esthetic outcomes improve greatly: open bite closure creates normal anterior contact appearance; reduced anterior display (in high-angle cases) decreases vertical maxillary excess visibility. Patient satisfaction exceeds 90% in completed cases, with functional improvements matching esthetic perceptions.
Contemporary vertical dimension correction integrates diagnosis precision, appropriate mechanical approach matching etiology, growth factor, and myofunctional component management. This full approach achieves high treatment success with minimal relapse and maximum long-term functional benefit.
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Related reading: Braces Discomfort Relief: Pharmacological and Adult Orthodontic Treatment Timeline: Conventional.
Conclusion
Talk to your dentist about your specific situation and what approach works best for you. Contemporary vertical dimension correction integrates diagnosis precision, appropriate mechanical approach matching etiology, growth factor, and myofunctional component management. This full approach achieves high treatment success with minimal relapse and maximum long-term functional benefit.
> Key Takeaway: Your vertical bite dimension — how much space exists between your upper and lower front teeth when they meet — determines whether you have normal.