AFTER MANDIBLE DISTRACTION FOR HEMIFACIAL MICROSOMIA Jang ng Hwan - - PowerPoint PPT Presentation

Department of Plastic & Reconstructive Surgery, Yonsei University College of Medicine Eastman Dental Clinic†, Seoul, Korea

FACTORS AFFECTING RELAPSE AFTER MANDIBLE DISTRACTION FOR HEMIFACIAL MICROSOMIA

Jang ng Hwan n Min, M.D., Seung ng Gee Kwon, M.D., Soon n Man Kwon†, DDS., Dong ng Kyun n Rah, M.D., Ph.D., Dae Hyun n Lew*, *, M.D., Ph.D.

HEMIFACIAL MICROSOMIA

Incidence rate: 1/3500~1/5600 Facial asymmetry

Unilateral underdevelopment

• Mandible, maxilla, zygoma
• External & middle ear
• Associated soft tissue & muscle

Disclosure: The authors have no conflict of interest to declare in relation to the contents of this article

Access factors influencing the relapse Define adequate amount of distraction

PURPOSE RELAPSE OF DOG

Controversy troversy

Hemifacial microsomia (unilateral)

2000~2011, 25 25 cases.

Mean follow up: 4yrs (range: 1yr~12yrs) Mean age : : 8.5yrs (range: 5yrs~37yrs)

Male : F Female = 18 : : 7 7

• Rt. : L
• Lt. (Affected side) = 1

14 : 1 11

PATIENTS & METHODS

OPERATIVE TECHNIQUE

1.Design& Exposure

• 3. Subtotal osteotomy

2.Selection of pin site 4.Pin insertion

• 5. Complete Osteotomy
• 6. Device application

Group by distraction amount Group by initial severity affected / n non-affected side

Group up 1 Group up 2 Group up 3 Group up 4 <10% 10%~2 ~20% 0% 20%~3 ~30% 0% >30% Group up A Group up B Group up C Group up D <10% 10%~2 ~20% 20%~3 ~30% >30%

PATIENTS & METHODS

Serial AP c cephalometry Facial height measuring Serial Panoramic view Mandible ramus height measuring Measuring time

• T0(PreOp): Preoperative initial
• T1(EOD): End of distraction
• T2(LFU): Long term follow-up

PATIENTS & METHODS

FACIAL HEIGHT MANDIBLE HEIGHT

Measurements

Ratio: affected side / n non-affected side Amount of d distraction (%) Final amount of l lengthening (%) Relapse (%)

PATIENTS & METHODS

RESULTS : OVERALL HEIGHT

RESULTS : OVERALL RATE

*P<0.05

RELAPSE RATE

GROUP BY INITIAL SEVERITY

Grou

• up

p A Grou

• up

p B Grou

• up

p C Grou

• up

p D <10% 0% 10%~2 %~20% 20%~3 %~30% >30% 0%

*P<0.0

0.05

RELAPSE RATE

GROUP BY DISTRACTION AMOUNT

Grou

• up

p 1 Grou

• up

p 2 Grou

• up

p 3 Grou

• up

p 4 <10% 0% 10%~2 %~20% 20%~3 %~30% >30% 0%

Factors affecting R Relapse

Amount of distraction

• Group 4 (

(>30%): Relapse ↑

• More distraction, more relapse

Initial s severity

• Group D (

(>30%): Relapse ↑

• More severity, more relapse

CONCLUSION

For m minimize r relapse

Adequate distraction amount

• Less than 30% distraction
• Not overcorrection

Multistage distraction Enough post op orthodontics

CONCLUSION