No abstract available.
Adult* ; Humans

Intraoral Vertical Ramus Osteotomy(IVRO) is a typical osteotomy procedure to setback the mandible for the prognathic patients and has many advantages functionally and morphologically, however, available data to predict the progressive prognosis on the functional rehabilitation of the mandible and the morphological change of the rami of the mandible after IVRO has been less reported. This is a prospective study for the progressive changes on the functional rehabilitation and the morphology of the rami of the mandible after IVRO for the Korean Prognathisms. 38 patients were studied for the functional rehabilitation and 21 patients were for the morphological change. Maxillo-Mandibular Fixation(MMF) was maintained for two weeks after IVRO and active physiotherapy was applied by means of Park's Protocol for next two weeks. Progressive change of the range of motion after release of MMF at maximum mouth opening, protrusion, lateral excursion(right and left) was recorded daily for 15days, and also recorded at 1st, 3rd, 6th, 12th, 18th months on the flow charts in the group for functional rehabilitation study. Nine measurements were measured to check morphological changes of the rami of the mandible at Immediate, 1, 3, 6 and 12 months postoperative period on Panex, P-A and Lateral Cephalometrics. The results were obtained as followings : 1. Mandibular function was returned rapidly during early 5 days after release of MMF, and reached to the almost normal range within 15days. And then slowly and progressively increased more and more afterward. 2. Recovery rate of the mandibular function after IVRO was depended upon the forcible application of a well-oriented protocol for active physiotherapy during early stage(within 15 days) after release of MMF. 3. Evidences of cortex-to-cortex healing between proximal and distal segments of the Mandible(CNS, CA, DOA on Panex) were definitely observed. They were changed slowly from immediate to 3 months but changed remarkably from 3 to 6 months of postoperative period, and then showed continuous but very slow changes afterward. 4. Vertical lengths of the proximal segments(RL, LL) were reduced remarkably from immediate to 3 month of postoperative period, and more slowly reduced from 3 to 6th month period, and then constantly reduced afterward as mimic rate. 5. Transverse distance between proximal segments(TL) was reduced rapidly within one month postoperatively and showed more slow and stable changes until one year follow-up period. 6. The gap between proximal and distal segments was disappeared rapidly within 6 month postoperatively, and then reduced very slowly afterward. 7. The change of Gonial angle(GA) was rapidly increased within one month of postoperative period and then increased very slowly afterward. In summary, mandibular function was returned to almost normal within two weeks after release of MMF, and osseous union was completely established between the proximal and distal segments without any complications in spite of early functional movement of the mandible without fixation between fragments. Morphological changes on the rami of the mandible was remarkable within 3 month period of postoperative and then continuously remodeled until one-year follow-up period. The application of a forcible and well-oriented protocol of active physiotherapy immediate after release of MMF may be the most important factor for prognosis of rehabilitation and morphological changes in IVRO.
Follow-Up Studies ; Humans ; Mandible ; Mouth ; Osteotomy* ; Postoperative Period ; Prognathism* ; Prognosis* ; Prospective Studies ; Range of Motion, Articular ; Reference Values ; Rehabilitation

No abstract available.

This investigation is an experimental study of the bone healing and remodeling process after Vertical Ramus Osteotomy(abbreviated as VRO) with early mobilization in adult dogs. Nineteen dogs were divided into three groups. Normal Control Group(N=2) was free of surgery. Experimental Group I(n=5) received only VRO without any intentional movements of distal fragments, and Experimental Group II(n=12) got VRO and backward driving of distal fragments. Animals were killed serially and the operated sites were reviewed grossly and histopathologically after the plain radiographs and Magnetic Resonance Images(abbreviated as MRI) were taken. The obtained results are as follows : 1. The early bone healing after VRO occurred mainly by the fusion of endosteal and subperiosteal calluses, and osteoinduced calluses from the cortices of fragments in intramembranous bone formation process. And the cartilaginous bone formations, which were considered to be associated with early functional movements of the mandible, were evident at the junction of these calluses. 2. The overlapping cortices of each fragment were fused by the osteoinduced calluses after decreased mobility of fragments mainly achieved by the subperiosteal calluses at the ateral and posterior part of pterygomasseteric sling. 3. Osteocytes in the cortices of fragments were dead by ischeinia and the marrow tissues were predominantly replaced by fibrous tissues in early stages. Active revascularization in the cortex and formation of new bone in the marrow, seen as the cancellous bones, were observed almost simultaneously and they were maintained until the 8th week when bone unions were confirmed. 4. Morphology of the mandible was changed byremodeling of the bone with reattachments of adjacent muscles after the 8th week. Callus in the gap was changed more and more into the compact bone after the 8th week, which united the proximal and distal fragments securely. 5. Low or iso-signal intensity at the cortex of fragments in early stages of MRI was being increased from the 4th week till the 12th week after VRO. The marrow spaces had high signal intensities on the T2-weighted images in early stages, but they returned to normal T1 and T2 high signals after the 12th week. 6. Signal intensities of the interfragmentary gap were high at the early stages and were gradually decreased to low signals at the 24th week. Atrophy of the masseter muscles with the high signal spots suggesting the increased vascularity was seen from the 2nd week, but the recovery of muscular volume with disappearance of high signal spots were also observed after the 8th week. In summary, the overlapped fragments made by VRO were completely healed by true bony union in adult dogs, even though they had cortex to cortex overlapping and early mobilizations had been allowed. Development of caelluses through the intramembranous bone formation, and the cartilaginous bone formations at the union of them tore mainly involved in the early bone healing. Direct communication of the marrows of the both segments was not found in this investigation, and more advanced study will be needed to explain the details of the fate of bony union after VRO.
Adult* ; Animals ; Atrophy ; Bone Marrow ; Bony Callus ; Dogs* ; Early Ambulation* ; Humans ; Magnetic Resonance Imaging ; Mandible* ; Masseter Muscle ; Muscles ; Osteocytes ; Osteogenesis ; Osteotomy*

No abstract available.
Jaw*

No abstract available.
Jaw*

No abstract available.
Orthognathic Surgery*

IVRO is a popular procedure to setback prognathic mandible. But guided functional physiotherapy after IVRO is the most important factor to get successful result, because there have been some concerns over an openbite tendency following this procedure. The purpose of this study is to evaluate the early adaptability to fuctional phsiotherapy and early openbite tendency associated with the kinds of surgery performed. The study was performed in fifty patients who had received bilateral IVRO from 1993 to 1994. After two weeks of maxillomandibular fixation(MMF), active physiotherapy was carried out according to Park's protocol and detail of openbite tendency was checked. We recorded the number of days for physiotherapy to analzye the adaptability in early physiotherapy until there was no more openbite tendency. The following results were obtained. 1. The adaptability in early physiotherapy to prevent openbite tendency following IVRO was more favorable in two-jaw surgery group than one-jaw surgery group.(p<0.005) 2. The adaptability in early physiotherapy was more favorable in lesser mandibular setback group than larger setback group, but there was no statistical significance. (p<0.05). 3. The adaptability in early physiotherapy was more favorable in posterior impaction group than non-posterior impaction group, but there was no statistical significance.(p<0.05). 4. The cases which MMF was applied again because of the strong openbite tendency were more plentiful in one-jaw surgery group than in two-jaw surgery group. 5. First two or three days after releasing of maxillomandibular fixation might be the critical period to prevent anterior openbite tendency, and if the partient shows strong openbite tendency during this period, 4-5 days of reapplication of MMF was enough to prevent openbite tendency .
Critical Period (Psychology) ; Humans ; Jaw Fixation Techniques ; Mandible ; Open Bite* ; Prognathism*

No abstract available.
Molar, Third* ; Paresthesia* ; Prospective Studies*

No abstract available.
Molar, Third* ; Paresthesia* ; Prospective Studies*