Outline from lecture on "Surgically Assisted Rapid Maxillary Expansion"
Outline from lecture given in Toronto, ON on May 6, 2001
Northway, W, Meade, J.,
AO, 67 (4) 309-320, 1997
Outline
Protocol
- Results of our study
- Associated problems
- Advantages of SARME vs RME or SME
- Indications for SARME
- Discussion: Potpourri of issues
Protocol
- Orthodontic consultation, treatment plan, and discussion
- Oral surgical consultation
- Records and fitting for expansion appliance
- Delivery of expander, (cemented or not)
- Surgery, (about the same morbidity as having 4 wisdom teeth removed)
- Allow 1 week for healing
- Begin expansion - typically for 2 weeks
- Ligation
- Initiate Orthodontics in 4-6 weeks
- Conversion, Removal, usually after 4 months
Upper Molar Width (at buccal grooves)
Upper Molar Width Changes (at buccal grooves)
Pretreatment Upper Molar Width
(at buccal grooves)Upper Canine Width Changes
(at most labial)Lehman and Haas, "Surgical-Orthodontic Correction of Transverse Maxillary Deficiency," Clinics in Plastic Surgery, #4, 1989
Sample size 34 females, 22 males
- Satisfactory expansion of all patients
- 17 required midpalatal osteotomy
- No specific measurements provided
Lower Canine Width Changes (at most labial)
Lower Molar Width Changes (at buccal grooves)
Palatal Depth at Premolars Changes
Palatal Depth at Molars Changes
Palatal Width at Premolars Changes
Palatal Width at Molars Changes
Pretreatment Palatal Width (at premolars)
Pretreatment Palatal Width (at molars)
Tipping at First Premolars (0.0889mm - 1 degree) Changes
Tipping at Molars (0.0889mm - 1 degree) Changes
Stripping at Maxillary Canines Changes
Stripping at Maxillary Premolars Changes
Stripping at Molars Changes
Greenbaum, K. And Zachrisson, B.
"The effect of palatal expansion therapy on the periodontal supporting tissues," A.J.O., 1982
- Compares 28 RME patients, 32 Quad Helix, and 28 Control (light-wire edgewise), adolescents
- Increase in maxillary molar width: 4.6mm, 4.3mm, -0.3mm
- When comparing level of marginal bone, attachment to CEJ distance, probing depths, and width of keratinized gingiva, there was individual variation, but no statistically significant differences.
Palatal Expansion in Adults
Summary
- With any of the approaches, expansion is predictable and stable.
- Reaching clinical objectives takes longer with a non-surgical approach; in my experience it is less painful with either of the surgical approaches.
- The verifiable, stable lower expansion that might accompany expansion is minimal.
- Tipping is negligible, relative to the impact of edgewise appliances
- Palatal depth change is minimal, may be influenced by extrusion or scarring.
- Palatal width is more profoundly influenced by a combined procedure.
- There is more gingival recession with a non-surgical approach.
Anticipatable Problems
- Pre-surgical acclimatization
- Post-surgical pain and swelling, possibly bruising (Tylenol and/or Ibuprofen)
- Complaints regarding diastema
- Do not allow smoking - one reported non-union - modify technique, advise tipped filter
- Avoid over-expanding
- Sinus infection - one case (pre-existing?)
- Diminished papilla (avoid free gingival margin)
- Does space always close?
Ralph, S.W., "A comparison of two rapid maxillary expansion appliances using three-dimensional finite element analysis,"
Master's Thesis, U. Mich, 1998
- A comparison of the Hyrax (Biederman, 1972 hygienic) expansion appliance with the Haas-type expander (with acrylic palatal coverage)
- The average tipping effect was 2.5-3 times greater with Hyrax than with Haas
- The Haas displaces teeth 26% more than the Hyrax in the transverse dimension
- Larger sutural displacement occurred with the Haas appliance.
- The Hyrax deformed more than the Haas, resulting in less energy affecting the sutures.
Vanarsdall, Robert L. "Transverse Dimension and Long-Term Stability" Seminars in Orthodontics, 5(3), 1-11, 1999
- While over-expansion of as much as 50% is recommended during orthopedic expansion, over correction is not recommended for surgically assisted expansion.
- Kuo ('90) showed that with SARME 84% of expansion was skeletal movement.*
Advantages of SARME over non-surgical expansion
- (RME or SME)
- Cost
- Pain
- Periodontal impact
- Facility of the procedure - do you have a good oral surgeon nearby?
- Asymmetries
Vanarsdall, Robert L. "Transverse Dimension and Long-Term Stability"Seminars in Orthodontics, 5(3), 1-11, 1999
- For the mature patient, a radiographic transverse maxillary deficiency greater than 5mm (5mm greater than 19.6mm), is directly correlated with gingival recession.*
Betts, Vanarsdall, et.al., "Diagnosis and treatment of transverse maxillary deficiency," Int. J.Adult Orthod Orthog Surg, 10: 75-96,1995.
- A discussion of the recognition, diagnosis, indications for, sequence, techniques and approaches of surgically assisted maxillary expansion.
Haas, A. "Long Term Posttreatment Evaluation of Rapid Palatal Expansion," A. O., 1980
- In a 19 year old male patient, he allowed the expansion to take place over approximately 3 months. "Since tissue borne appliances act high on the base, it is visualized that a high alveolar and apical base expansion took place rather than the low alveolar expansion which results when teeth are expanded by the use of conventional appliances."
Handelman, C., "Nonsurgical rapid maxillary alveolar expansion in adults: a clinical evaluation," A.O, 67 (4), 291-308, 1997
- 5 adult patients, treated by non-surgical expansion are presented
- Limiting the rate of expansion is presented as being critical in controlling pain, swelling and ulceration.
Handelman,C., et. al., "Nonsurgical Rapid Maxillary Expansion in Adults: Report on 47 Cases Using the Haas Expander," AO, 70 (2), 129-44, 2000
- Sample:
- 47 Adult RME
- 46 Children RME
- 53 Adult orthodontic patients (controls)
- Findings:
- The procedure was well tolerated
- Vertical dimensions were unchanged
- Complications were infrequently observed
- Expansion caused by warping the alveolus, rather than palatal split
- The expansion was sufficient to correct crossbites
- Corrections were stable over time
- Buccal angulation flared 3 /side
- Buccal attachment loss was not statistically significant for males but was for females - even more so when a buccal bar was used.
Capelozza, L., "Non-surgically assisted rapid maxillary expansion in adults" Int. J. Adult Orthod Orthognath Surg., 1996
- 38 Patients with a mean age of 20 y, 8 mos
- 81.5% achieved a diastema (definition of sutural opening)
- Morbidity ranged from mild discomfort to significant pain, edema and palatal lesions
- Only moderate expansion was possible, but enough to obtain satisfactory interocclusal relations. (S = 1.46, 3.6, and 3.26 at canine, premolar and molar respectively)
Until what age can you still do non-surgical expansion?
Krebs,A., "Midpalatal suture expansion studied by the implant method over a seven-year period," Trans Eur Orthod Soc., 131-42, 1964.
- 23 patients with bilateral crossbites (12 boys, 11 girls; ages: 8 - 19) received metal implants per Bjork's method.
- Used cephs and dental casts
- Followed for 7yrs after RME, the differing effects on five facial zones was compared as a function of age.
- Due to sample size, the effects of age, sex, duration of treatment and severity of malocclusion were not immediately predictably clear.
- While he found that nasal and maxillary width changes were relatively stable, the changes in dental arch width were not for many individuals - a steady decrease recorded up to 4-5 years after treatment.
Cameron, C.G., "Short-term and long-term effects of rapid maxillary expansion: a posteroanterior cephalometric and morphometric evaluation," Master's Thesis, U. Mich, 2000
- A comparison of the effects of the Haas-type expander with untreated children from the Ann Arbor growth sample
- 42 expansion patients (25 female and 17 male)
- 20 untreated subjects (9 female and 11 male)
- Clinically significant changes:
- nasal width increase 2.7mm (larger than control)
- maxillary width increase 2.3mm (almost restoring the deficiency of the treatment group)
- maxillary first molars increased by 3.5mm; increase in arch perimeter of 2.5mm (1.5 of -2.0 deficiency)
- mandibular first molar increased by 1.4mm (over- correction of deficiency by 0.8mm)
- "There were no significant differences between the two groups in skeletal or dentoalveolar changes based on whether they were expanded before the peak in skeletal maturity or at or after the peak in skeletal maturity with the exception of lateral nasal width... RME can be started anytime in adolescence."
- Osteopetrosis - increased density
- Collagen vascular disease
- Stenosis
- Ankylosis of the midpalatine suture
- 38 Patients with a mean age of 20 y, 8 mos
- 81.5% achieved a diastema (definition of sutural opening)
- Morbidity ranged from mild discomfort to significant pain, edema and palatal lesions
- Only moderate expansion was possible, but enough to obtain satisfactory interocclusal relations. (S = 1.46, 3.6, and 3.26 at canine, premolar and molar respectively)
- The response to orthopedic maxillary expansion was studied
- Biopsies from 2 boys and 6 girls (ages 8-13) were compared to autopsy material
- The histology of the healing process following rapid expansion was compared with that of the midpalatal suture of untreated children in the same age group.
- Can a sufficient increase in palatal vault volume improve the prognosis for lateral openbite reduction?
- We have model analysis
- We have lateral and P-A cephalometry (lateral is especially well accepted)
- Midface fullness is still an art, not science
- While the studies are inconclusive, one must wonder what the outcome would be if the patients had received complete palatal separation.
- S.A.R.M.E. does not created positional changes in the nasal septum (Bell and Epker)
- This procedure results in increases in the nasal airway space.
- There is a rotational expansion of the maxilla with a resultant inferior rotation of the palatal shelves.
- 38 RME patients had nasal resistance measurements compared with controls and again after 9-12 months.
- Some individuals treated with RME had significantly higher resistance readings than the control group.
- There was a significant median reduction in resistance following expansion, which measured stable one year later.
- RME was most effective at the anterior nares.
- Individual variation in resistance was considerable, making RME not a predictable means of decreasing nasal resistance.
- Nasal resistance measurements were taken on RME patients prior to expansion, immediately after expansion, following removal and again 12 months later.
- There was a significant reduction in resistance (48.7%).
- This reduction was stable; the groups remained significantly lower than the initial reading, but not differ from each other.
- Reduction in resistance was correlated with initial resistance: those with greatest resistance had the greatest improvement.
- Harper, Bell
- Guerrero, Bell, et.al.
- British Journal of Oral and Maxillofacial Surgery, 1997
- Mandibular widening through Distraction Osteogenesis at the symphysis
Is Maxillary Constriction Normal?
Is there a gradient of transverse hypoplasia?
Capelozza, L., "Non-surgically assisted rapid maxillary expansion in adults" Int. J. Adult Orthod Orthognath Surg., 1996
Melsen, B., "A histological study of the influence of sutural morphology and skeletal maturation on rapid palatal expansion in children" Trans Eur Orthod Soc., 499-507, 1972.
One more question...
Facial Fullness Analysis...
Does/can expansion have an effect on nasal resistance?
Schwarz,G., et.al., "Tomographic assessment of nasal septal changes following surgical-orthodontic rapid maxillary expansion," AJO, 87(1), 1985.
Hartgerink, D, Vig, P, Abbott, D, "The effect of rapid maxillary expansion on nasal airway resistance," AJODO, 92(5), 1987
White,B, Woodside,D, and Cole,P, "The effect of rapid maxillary expansion on nasal airway resistance," J. Otolaryngol,18(4) 1987