Open-bite: stability after bimaxillary surgery - 2-year treatment outcomes in 58 patients

Abstract

Stability after bimaxillary surgery to correct open bite malocclusion and mandibular retrognathism was evaluated on lateral cephalograms before surgery, 8 weeks post-operatively, and after 2 years. The 58 consecutive patients were treated to a normal occlusion and good facial aesthetics. Treatment included the orthodontic alignment of teeth by maxillary and mandibular fixed appliances, Le Fort I osteotomy, and bilateral sagittal split ramus osteotomy. Twenty-six patients also had a genioplasty. Intra-osseous wires or bicortical screws were used for fixation. Twenty-three patients had maxillo-mandibular fixation (MMF) for 8 weeks or more, six for 4-7 weeks, 14 for 1-3 weeks, and 15 had no fixation. At follow-up 2 years later, the maxilla remained unchanged and the mandible had rotated on average 1.4 degrees posteriorly. Seventeen patients had an open bite. Among them, eight patients had undergone segmental osteotomies. The relapse was mainly due to incisor proclination. The most stabile overbite was found in the group with no MMF after surgery.

Combined Orthodontic and Orthognathic Surgical Treatment for the Correction of Skeletal Anterior Open-Bite Malocclusion: A Systematic Review on Vertical Stability

“…In the long-term follow-up, the mean changes ranged from Ϫ0.1°(closing) 6 to 0.6°(opening) 45 for Le Fort I surgery and from Ϫ0.3°(closing) 46 to 0°6 for bimaxillary surgery; no data were found for BSSO surgery. …”

“…6,7,[44][45][46][47][48][49][50] Using the quality evaluation according to the Swedish Council on Technology Assessment in Health Care, 20 most of these studies were scored as grade C (low value of evidence) and only 2 were ranked as B (moderate value of evidence). None were graded as having a high value of evidence (grade A).…”

“…Five studies were judged to have an adequate sample size (30 to Ͼ250). 6,[44][45][46][47] The ethnic background of the patients was not available in all the reviewed studies. Four of the studies did not include an error of the method analysis or it was not reported.…”

“…When considering the concomitant use of a genioplasty, 6 studies declared that an additional genioplasty was performed in some patients. 6,[44][45][46]49,50 …”

“…No long-term follow-up data were available for BSSO surgery. For bimaxillary surgery, long-term overbite changes ranged from a mean decrease of 0.5 mm 46 to an increase of 0.5 mm. 49 The 2 studies with overbite measurements from after orthodontic treatment to after follow-up showed a mean decrease in overbite of 0.3 mm 7 in the long term (mean, 4.5 yrs) after orthodontics and bimaxillary procedures and a decrease in overbite of 1 mm 48 in the long term (median, 3 yrs) after orthodontics and Le Fort I surgical procedures.…”