Download Little -- Orthodontic Stability and Relapse

UNIVERSITY OF WASHINGTON
SEATTLE
CLINICAL IMPLICATIONS ‐‐
UNIVERSITY OF WASHINGTON
UNIVERSITY OF WASHINGTON
POST‐RETENTION ALIGNMENT STUDIES
ROBERT M. LITTLE, DDS, MSD, PhD
PROFESSOR EMERITUS
UNIVERSITY OF WASHINGTON
UNIVERSITY OF WASHINGTON
SUMMARY
LESSON # 1: NATURE & EXTENT
OF POST‐RETENTION CHANGE ARE UNKNOWN
ARE UNKNOWN CLINICAL IMPLICATION:
PLAN ON LIFETIME PERMANENT RETENTION LESSON # 2a
LESSON # 2a: ARCH LENGTH & ARCH WIDTH TYPICALLY CONSTRICT POST RETENTION
TYPICALLY CONSTRICT POST‐RETENTION
CLINICAL IMPLICATION:
1. AVOID INCREASING ARCH LENGTH AND WIDTH DURING TREATMENT 2. PLAN ON LIFETIME PERMANENT RETENTION LESSON # 2b
LESSON # 2b: ARCH LENGTH & ARCH WIDTH TYPICALLY CONSTRICT POST RETENTION
TYPICALLY CONSTRICT POST‐RETENTION, BUT LESS SO FOR A FEW LUCKY ONES
CLINICAL IMPLICATION:
EXPECT MINIMAL RELAPSE IN CASES THAT
HAVE ADEQUATE OR EXCESS PRETREATMENT
ARCH LENGTH
LESSON # 3:
LESSON # 3:
EARLY STABILITY MAY BE A MIRAGE ‐‐
FOR MOST, IN A FEW YEARS THE HONEYMOON WILL BE OVER
HONEYMOON WILL BE OVER
CLINICAL IMPLICATION:
LIFETIME PERMANENT RETENTION IS THE ONLY WAY TO ENSURE ALIGNMENT STABILITY
LESSON # 4
LESSON # 4
ROTATIONS ARE UNPREDICTABLE
CLINICAL IMPLICATIONS:
PLAY IT SAFE
BOND EACH INCISOR TO THE MANDIBULAR FIXED RETAINER
KEEP THE FIXED RETAINER FOR LIFE
UTILIZE SUPRACRESTAL FIBEROTOMY FOR INCISORS THAT
WERE ROTATED PRE‐TREATMENT
LESSON # 5
LESSON # 5
LABIAL AND LINGUAL RELAPSE ARE UNPREDICTABLE
CLINICAL IMPLICATION:
MANDIBULAR ANTERIOR STABILITY MANDIBULAR
ANTERIOR STABILITY
IS A RARE OCCURRENCE
LIFETIME PERMANENT RETENTION IS THE ONLY RELIABLE METHOD TO ENSURE
THE ONLY RELIABLE METHOD TO ENSURE LONG‐TERM SUCCESS
LESSON # 6
EARLY TREATMENT CAN PAY OFF
CLINICAL IMPLICATION:
MAINTAIN LEEWAY SPACE
IN CASES WHERE ARCH LENGTH
IN CASES WHERE ARCH LENGTH
IS FAVORABLE
(NANCE WAS RIGHT !)
LESSON # 7
LESSON # 7
SERIAL EXTRACTION YIELDS NO BETTER POST‐RETENTION RESULTS THAN LATER PREMOLAR EXTRACTION
THAN LATER PREMOLAR EXTRACTION
CLINICAL IMPLICATION:
CLINICAL IMPLICATION:
PERMANENT RETENTION PERMANENT
RETENTION
EVEN IF SERIAL EXT DRIFT STAGE IS FAVORABLE
STAGE IS FAVORABLE
LESSON # 8
LESSON # 8
ARCH DEVELOPMENT IS UNSTABLE
(THE MOST SEVERE RELAPSE THAT WE HAVE STUDIED )
CLINICAL IMPLICATION:
PERMANENT RETENTION IS MANDATORY
GINGIVAL RECESSION AND DEHISCENCE ARE POSSIBLE SEQUELLA
ARE POSSIBLE SEQUELLA
LESSON # 9
LESSON # 9
A. RETENTION POSTPONES RELAPSE
B. RELAPSE IS PROGRESSIVE THROUGHOUT LIFE C. RATE OF RELAPSE SLOWS WITH AGE
C. RATE OF RELAPSE SLOWS WITH AGE
CLINICAL IMPLICATION:
LIFETIME PERMANENT RETENTION TO ENSURE LONG‐TERM SUCCESS
LESSON # 10
SSON # 0
QUALITY MATTERS
QUALITY MATTERS
CLINICAL IMPLICATION:
STRIVE FOR THE HIGHEST QUALITY RESULT
MAINTAIN THE CORRECTION WITH LIFETIME RETENTION
STABILITY AND RELAPSE - SELECTED REFERENCES:
1. Little, R.: The Irregularity Index: A quantitative score of mandibular anterior alignment. Am J
Orthod 68: 554-563, 1975.
2. Little, R., Wallen, T., Riedel, R.: Stability and relapse of mandibular anterior alignment. First
premolar extraction cases treated by traditional edgewise orthodontics. Am J Orthod 80: 349-365,
1981.
3. Sinclair, P., Little, R.: Maturation of untreated normal occlusions. Am J Orthod 83: 114-123, 1983.
4. Gilmore, C., Little, R.: Mandibular incisor dimensions and crowding. Am J Orthod 86: 493-502,
1984.
5. Sinclair, P., Little, R.: Dentofacial maturation of untreated normals. Am J Orthod 88: 146-156,
1985.
6. Little, R.: Riedel, R., Artun, J.: An evaluation of changes in mandibular anterior alignment from 10
to 20 years postretention. Am J Orthod Dentofac Orthop 93: 423-428, 1988.
7. Little, R., Riedel, R.: Postretention evaluation of stability and relapse. Mandibular arches with
generalized spacing. Am J Orthod Dentofac Orthop 95: 37-41, 1989.
8. Ades, A., Joondeph, D., Little, R., Chapko, M.: A long-term study of the relationship of third
molars to mandibular dental arch changes. Am J Orthod Dentofac Orthop 97: 323-335, 1990.
9. Little, R., Riedel, R., Stein, A.: Mandibular arch length increase during the mixed dentition:
Postretention evaluation of stability and relapse. Am J Orthod Dentofac Orthop 97: 393-404,
1990.
10. Little, R., Riedel, R., Engst, E.: Serial extraction of first premolars – postretention evaluation of
stability and relapse. Angle Orthod 60: 255-262, 1990.
11. Riedel, R., Little, R., Bui, T.: Mandibular incisor extraction – postretention evaluation of stability
and relapse. Angle Orthod 62: 103-116, 1992.
12. Little, R.: Stability and relapse of mandibular anterior alignment - University of Washington
studies. Seminars in Orthod 5: 191-204, 1999.
13. Ormiston, J., Huang, G., Little, R., Decker, J., Seuk, G.: Retrospective analysis of long term
stable and unstable orthodontic treatment outcomes. Am J Orthod Dentofac Orthop 128: 568574, 2005.
14. Little, R., Sinclair, P.: Clinical implications of the University of Washington post-retention studies.
J Clin Orthod 43: 645-651, 2009.
15. Little, R., Sinclair, P.: JCO Interviews: Dr. Robert M. Little on the University of Washington postretention studies. J Clin Orthod 43: 723-747, 2009.