Tuesday, April 23, 2013

Case of the Month: April 2013 (Orthognathic Surgical Correction)

This month's case illustrates the sometimes life changing transformation that orthodontics combined with orthognathic (jaw) surgery can make.  This particular patient presented to our office at age 15 wanting straighter teeth, an improved bite and an increase in the prominence of her lower jaw.

She was diagnosed as having a constricted maxilla (upper jaw), retrusive mandible (lower jaw) in part to a high jaw angle, proclined and protrusive upper incisors (front teeth), and an excessive overjet (front to back distance between the upper and lower incisors).  Her facial balance needed improvement due to the lower jaw being so retrusive, which also causes the lip balance to appear strained when trying to keep the lips closed.

The initial cephalometric radiograph below illustrates the jaw and bite discrepancies from a lateral view (patients facial photos are not shown for privacy purposes):

During our orthodontic consult, we explained that jaw surgery would be required to meet all of the patient's goals and expectations due to the severity of the skeletal discrepancies.  Many cases with more mild skeletal problems can be fixed with orthodontics alone, but some cases require the jaw bones themselves be moved to create the proper balance.  A referral was made to Dr. Steve Widner, an oral surgeon in central Austin.  After discussing the patient's case, Dr. Widner and I agreed that two-jaw surgery involving expanding the upper jaw along with tipping the back part of the upper jaw up and an advancement of the lower jaw would meet everyone's expectations.  The upper front teeth would also have space to tip back once the upper jaw was widened surgically.

Orthodontic treatment was initiated with the expected 12 months of pre-surgical tooth movements needed.  Essentially it is the orthodontist's job to align and level each arch individually so that when the jaws themselves are moved, the dental arches and bite will fit together nicely.  Once we were ready and all preparations were made, the jaw surgery was completed and about 9 months of post-surgery orthodontic finishing was done.  Jaw surgery usually requires 2 weeks of rest (usually no school or work) post-surgery and patients start feeling 100% about a month after the surgery.  A month of rest and healing is worth the dramatic quality of life improvement in my opinion.

The following before and after photos impressively illustrate the powerful changes that jaw surgery combined with orthodontics can make for those who can benefit from it:

Believe it or not that is the same patient in the before and after photos and needless to say she is thrilled and can't wait to start college.

Sunday, January 6, 2013

Case of the Month: January 2013

The following case will demonstrate the effectiveness of early orthodontic intervention to address an ectopically erupting tooth (a tooth erupting in the wrong direction or location) followed by the use of pre-molar extractions during comprehensive treatment to alleviate severe crowding.

The patient presented to the office at the age of 9 having been sent by her pediatric dentist due to a mandibular incisor erupting ectopically.

 As you can see above, the lower right lateral incisor erupted backwards in the dental arch, while the primary (baby) incisor (yellow X) that should have been lost was not.  This is obviously a problem because the canine and first pre-molar on that side would be blocked from erupting in the future.  She was sent back to her pediatric dentist to remove the retained primary incisor and limited braces on the front four incisors was initiated to tip the ectopic tooth into the correct position.  Because the patient was in the mixed dentition stage (half primary teeth/half permanent teeth), we call any orthodontic treatment at this time early or interceptive because we are essentially ensuring that a normal eruption process can occur.  Other common early or interceptive treatments include maxillary expansion and various types of headgear if a patient has a large enough jaw growth discrepancy. 

The total treatment time for the interceptive treatment was 7 months and the picture below shows the lower incisors in better position.

We continued to monitor the patient's tooth eruption pattern periodically over the next two years and comprehensive orthodontic treatment (full braces once all permanent teeth are in) was initiated at age 12.  When the patient returned almost ready for her comprehensive treatment, she had severe crowding due to a large tooth size/jaw size discrepancy and the decision was made to extract all of the permanent first pre-molars.  Orthodontists try to not have to extract permanent teeth, but the lower jaw limits our ability to expand because the jaw itself does not expand like the upper jaw because it does not have a growth suture in the midline and we also have to be careful not to push the teeth too far forward when aligning them and cause gingival recession. 

 The panoramic radiograph above shows the crowding issues, especially in the lower jaw where some of the canines and pre-molars don't have enough space to erupt.  A referral to her dentist was made to extract the first pre-molars and she returned in 6 months after the remaining teeth erupted to begin her comprehensive treatment.  The pictures below show how she presented at that time.

We then proceeded to place full braces on both arches.  After aligning and leveling each arch, the remaining extraction space needed to be closed.  The patient did a great job wearing rubber bands for us and otherwise did not need any other kinds of appliances.  The pictures below show the nice finish with excellent alignment, great esthetics and all teeth positioned well within their bony housing for long-term good periodontal health.

The total treatment time for phase II or her comprehensive treatment was 20 months, which is pretty typical for extraction cases.  If you look carefully, you can see that we are missing all of the first pre-molars, but no one would ever be able to tell.  Many people you know may have been effectively treated with extractions by their orthodontist.  As I stated earlier, we only extract when we absolutely have to (about 10% of cases in my practice), but extraction cases can work out very nicely when the proper diagnosis and treatment plan is followed.