STABILITY OF INTRAORAL VERTICOSAGITTAL RAMUS OSTEOTOMY IN MANDIBULAR SETBACKS: RETROSPECTIVE ANALYSES OF 40 CASES. Gil, L.F.; Marin, C.; Granato, R.; Claus, J.D.P.; Cruz, D.S.M. da; Poubel, V. L. N.; Gil, J.N. Federal University of Santa Catarina – Universitary Hospital - Brazil [email protected] RESULTS

OBJECTIVES The intraoral verticosagittal ramus osteotomy (IVSRO) was first

The mean surgical setback was 3.87 ± 1.84 mm and the mean

described by Choung1 to correct mandibular prognathism. This

horizontal relapse was 0.56 ± 0.27 mm after 1 year of follow-up.

osteotomy produces a contact area between the proximal and

There was a significant correlation between amount of setback

distal segments allowing movements as mandibular setbacks,

and

advancements and rotations. Although this technique has

correlation between gender or age and relapse (p>0.05).

relapse

(p<0.001)

(Fig.

2),

whereas

there

was

no

potential benefits in decreasing neurosensory disturbance and no necessity of rigid fixation, there is few published data about

1,6

its stability. The aim of this retrospective study was to evaluate

1,4

the stability of IVSRO in mandibular setbacks.

IVSRO was designed according to Fujimura2. All surgeries were performed by the same surgeon and MMF was applied for 21 days. Lateral cephalograms of 40 patients (19 males and 21 females) who underwent IVSRO in single-jaw or 2-jaw surgery were analyzed. The patients ranged in age from 18 to 33 years (mean age, 26.1 years). Horizontal relapse was obtained by tracing cephalograms in 3 different periods of time: preoperative (T0), within 1 month of surgery (T1) and at least 1 year of

RELAPSE

MATERIALS AND METHODS

1,2 1 0,8 0,6 0,4 0,2 0 0

2

4 SETBACK

6

8

Fig. 2 - Graphic showing the correlation between setback and amount of relapse at the B point.

follow-up (T2). The distance between the B point and a vertical line were accessed between T0 and T1 (setback) and T1 and T2

CONCLUSIONS

(relapse) (Fig. 1). Chi-square test was performed for statistical analyses.

In this sample, IVSRO was a stable technique. Further studies are necessary to confirm these findings. Nasion 6°

REFERENCES 1- CHOUNG PH. A new osteotomy for the correction of mandibular prognathism: Techniques and rationale of the intraoral verticosagittal ramus osteotomy. J Craniomaxillofac Surg 1992: 20: 153.

B Point

2- FUJIMURA K, SEGAMI N, SATO J, KANAYAMA K, NISHIMURA M, DEMURA N. Advantages of intraoral verticosagittal ramus osteotomy

in

skeletofacial

temporomandibular Fig. 1 - Cephalometric landmarks and reference line used in the study.

Surg 2004: 62 :1246.

joint

deformity

disorders.

J

patients Oral

with

Maxillofac