Non-surgical anterior open bite closure.  Flaring of the upper and/or lower anterior teeth due to orthodontic unraveling of crowded teeth can lead to shallowing of the anterior overbite (called by some the drawbridge effect).  If the overbite was shallow prior to treatment an anterior open bite can result.  This is why I tend to prescribe more premolar removals for crowded cases with shallow overbites and proclined incisors.  If I suspect that first premolar removals may lead to loss of lip support I will suggest removal the second premolars.


 
 

 
 

 
 

Open bite surgical/orthodontic cases.  Open bite cases pose a challenging problem.  They can many times be closed by orthodontic means only but, have a high tendency for relapse (especially on a non-extraction basis).  In adults that do not require extractions, the orthodontic closure of anterior open bites utilizing elastics will many times reopen.  In these cases, surgical posterior maxillary impaction allows for auto rotation of the mandible and a stable open bite closure.  I will leave the second molars slightly out of occlusion and allow them to spontaneously erupt since these may have been the only teeth to occlude prior to treatment.  More next week on non-surgical open bite closure.

Class II surgical/orthodontic cases.  If the mandible is too retrognathic, surgical advancement may be in order.  Unlike class III surgical cases we do not always have to wait for growth to cease prior to pursuing the surgery.  The surgeons tell me that the mandible must be matured to the point that it does not splinter or greenstick fracture during surgery.  Prior to the surgery it is necessary for us to level the curve of Spee in the lower arch and close all lower spaces that are not planned for implants or restorations. Otherwise, maximum advancement of the mandible cannot be expressed.  Surgical advancement of the mandible will improve the airway in most retrognathic patients and may lessen the chance for obstructive sleep disorders in the future.

Class III surgical/orthodontic cases.  Patients that display significant class III malocclusions will many times require orthognathic surgery in cooperation with their orthodontic treatment (once growth has ceased).  It is not uncommon to find the upper incisors flared facially while the lower incisors are retroclined lingually.  It is important to consider the airway, overbite and profile when determining if the mandible needs to be positioned distally, the maxilla mesially or both.  Since it is wise to wait on definitive orthodontic treatment until growth has stopped, we will sometimes pursue a first phase of upper braces while the patient is growing to facilitate a nice smile and increased self-confidence. 

Mesially erupting mandibular second molars continued.  When we diagnose a mesially tipping mandibular second molar as it erupts we must look at the crowding present in the arch.  Many times crowding is present and that contributes to the molar’s deviation.  Premolar removal treatment must be considered as this will allow the lower first molars to drift mesially thus giving the second molar a better eruption path.  Lower second premolar removal facilitates this the best.  If the case is a borderline extraction case, mesially tipped mandibular second molars being present may swing the pendulum toward extraction of lower second premolars.

Mesially erupting mandibular second molars.  We have recently covered mesially erupting (ectopic) maxillary first molars.  It is not uncommon to see the lower second molars erupting with a mesial cant that can sometimes find them caught under the distal aspect of the first molar.  Diagnosing these early is important since once they are caught these second molars may continue to tip until they are almost horizontal and become unsalvageable.  If braces are in place and there is adequate room in the arch we can attach a second molar bracket and upright the tipped tooth.  It may be necessary to remove some of the buccal tissue with a laser in order place the bracket.  Next week more on this topic when there is lower crowding.
 
 
 
 

We're here every day.  Our practice model has been to stay at one location.  I'm here four days per week and keep support staff there the fifth day in order to answer phone calls and take care of minor emergencies.  I'm the only orthodontist at the office and they see me each appointment.  Patients seem to like the continuity of care and the fact that the office is always fully staffed if they need us.  All of our orthodontic records and bracket placement appointments are accomplished in the office location they have chosen without them wondering where we are practicing today.  We are able to have a full service in-house lab daily for immediate repairs and excellent Doctor/Lab communication.  Come by anytime for a tour of our facility at 12800 Metcalf Avenue!

What is the reason and timing of deciduous tooth extractions?  An early panoramic radiograph is important to uncover developmental dental problems.  Determining if there are missing teeth allows us to direct them down the proper path for either future restoration or complete space closure.  This gives the child's parent relief that the prognosis for an excellent dental environment is great.  Parents never like to be surprised by the report of missing permanent teeth when their child is expecting eruption of those teeth.  Finding deviant eruption of permanent teeth early allows us to guide these tooth into the proper position thus lessening the amount of future orthodontic movement.  Impacting canines is what we probably see the most. 

Missing Permanent Teeth (Hypodontia/Oligodontia).  Third molars are the teeth found to be most commonly missing (about 23% of the population).  Second premolars are next followed by maxillary lateral incisors.  Keeping mandibular second deciduous molars presents an interesting situation since they tend to be much wider mesio-distally than the underlying premolars (average 1.7mm wider).

Orthodontic intrusion of worn anterior teeth.  I recently had a study club discussion regarding proper positioning of worn anterior teeth in preparation for restorations (crowns, veneers or composite build ups).  Orthodontics is many times necessary for these patients due to the supereruption that occurs as attrition takes place.  We can orthodontically intrude either the upper, lower or all anterior teeth.  I base a lot of this decision on the upper lip to incisor relationship both during rest and smiling.  We also need to take into account the clinical crown length of the worn teeth.  If I can place the teeth in the correct position with proper overjet, a fantastic functional and esthetic result can be had.  These patients refer others to your office since they are walking billboards for your practice.  By the way, we always get before and after photos that you are welcome to use.

 

 

                                     

Quicker turnaround with Invisalign cases.  Now that we utilize digital imaging models for Invisalign cases the time it takes from imaging and records to insertion of the first trays is shortened. Federal Express is quick but the internet transfer is even quicker! The patients appreciate getting started on their treatment sooner since they are excited to see change in their malpositioned teeth. Two weeks from imaging to insertion is very possible!

We all hate impressions!  Our adult and young patients would all tell you that impressions might be what they fear the most at the orthodontist.  We have utilized an I-Cat cone beam scan to gain not only our radiographs but digital models for quite some time.  Recently we have added the new iTero Element visual scanner. We can utilize this for study models, Invisalign treatment, and appliance construction without the need for impressions.  It is much faster than previous models and the images are more universally accepted.  Now we see smiles not only after orthodontics but before as well when they can use the iTero without impressions!

Fluoride Treatment Prior to Orthodontic Bracket Placement.  If you are providing a prophylaxis immediately prior to placement of orthodontic brackets, we suggest not utilizing fluoride at that appointment.  It can weaken the bond strength of the composite leading to brackets dislodging easier.  We always supply the patient with their first bottle of acidulated fluoride rinse at their bonding and ask them to use it nightly throughout treatment.

Lower incisor position and profile changes in extraction treatment.  I am often asked about the effect of upper premolar extraction treatment on the facial profile and many believe that this will significantly retract the upper and lower lip positions.  In most orthodontic cases we must treat the occlusion to the labiolingual position of the lower incisors.  This is because the bone surrounding them is thin both on the facial and lingual aspect of their roots.  If the maxillary anterior teeth are more crowded than the lowers and a class II molar relationship is present, there is usually not a significant overjet.  When upper premolars are removed in these cases the maxillary canines are retracted into the missing premolars' positions and the incisors are uncrowded.  The lower incisors are held in their most stable and healthy location while the overbite and overjet is coordinated to them.  Thus, the profile won't change much and proper canine and incisal guidances are obtained.  Next we'll talk about how the anterior-posterior relationship of the maxilla and mandible relate to profile and incisor angulation. 

Facial profile relationship to extraction treatment.  Facial profile and lip fullness go hand in hand with skeletal and dental positions.  When a thin or retracted lip appearance is present we try our best to treat the patient on a non-extraction basis.  Likewise, when there is a very protrusive lip pattern we consider premolar extractions a bit more often.  If severe crowding is present, extractions will not change the lip pattern much because most of the extraction space is utilized to uncrowd the dentition.  This can be both a blessing and a curse.  In thin lip patterns you will not lose lip support by pursuing extraction orthodontic treatment.  Likewise, with very protrusive lips you will not get as much softening as you might desire.  Another item to consider is the nasolabial angle (angle between the bottom of the nose and upper lip.)  An obtuse nasolabial angle (with upturned nose) requires careful consideration before removing premolars for treatment.  Next week we'll consider the relationship of the lower incisor to facial profile changes.

Indicated extractions in treatment of class II and III malocclusions.  Extraction of premolars may be indicated in order to orthodontically correct malocclusions where growth has ceased and the maxilla and mandible are not matching.  In order to mask a prognathic mandible it is sometimes necessary to remove a lower premolar bilaterally in order to incline the lower incisors lingually and distalize the canines. If we are treating a class II malocclusion without significant lower crowding we can extract two upper premolars in order to gain a tight overjet and class I canines.  With these or any extractions it is wise to take the facial profile into account as we treat the malocclusion.

How anterior overbite relates to extraction needs.  The amount of anterior overbite or openbite a patient has plays an important role in uncrowding of the dentition.  When we see a slightly open or shallow overbite malocclusion that displays crowding a red flag can go up.  Uncrowding of the teeth tends to lean the incisors somewhat labially and this will lead to more opening of the anterior overbite.  Even if the vertical elastics are used to deepen the bite, open bite tendencies may return after removal of the braces.  On the other hand, spaced dentitions will tend to deepen during orthodontics and space closure.  An easy way to visualize this is to think of a draw bridge and what happens as the two halves are leaned upward or brought back toward the water. 

More about expansion versus extraction treatment.  I prefer to treat cases in a non-extraction manner whenever possible.  If the patient does not display posterior crossbites we must be careful to not overly expand the maxillary arch into buccal crossbite.  If the lower arch needs, and will withstand, some expansion I will expand the upper arch slower in hope that the occlusion with "drag" the lower posterior teeth along.  Severe mandibular crowding may necessitate premolar extraction treatment so that we do not flare the lower incisors labially and out of the alveolar bone.  This can lead to future boney and gingival dehiscence and periodontal problems.  Over the next few Weekly Tips we will discuss how lip appearance, class II and class III occlusion, overbite and upper/lower tooth size discrepancies affect extraction decisions. 

Expansion versus extraction treatment decisions.  I probably get the most questions regarding the decision to expand the arches versus extract permanent teeth.  I'll limit the discussion here to children and adolescents.  Anatomical development finds the mandibular midline suture closed before one year of age while the maxillary midline suture can widened into the teens in many cases.  For this reason significant upper expansion is much more obtainable than the same procedure in the lower arch.  Thus, extraction decisions in many cases are made after carefully reviewing the amount of space needed in the mandibular dentition.  We have to look not only at the amount of crowding present but also the degree of overbite correction, class II or III correction and tooth uprighting necessary.  More on how I make these decisions next week.

Tip of the Week

When I use our diode laser.  I have successfully used a laser in our office for over 10 years to enhance speed of treatment and esthetics.  The laser is routinely used 2-3 weeks prior to bracket removal in order to size back the enlarged and fibrous gingival tissue that can occur with less than excellent oral hygiene.  The gingival margins can be leveled bilaterally giving symmetry to the completed smile.  The soft tissue diode laser is invaluable when tissue removal is necessary to bracket an erupting canine or lower second molar.  This can save months of treatment time instead of waiting for that one tardy tooth!