• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제41권
• /
• pp.8.1-8.6
• /
• 2019

Background: Resorbable devices have recently been adopted in the field of orthognathic surgery with controversies about their postoperative skeletal stability. Hence, we determined the long-term skeletal stability of unsintered hydroxyapatite/poly-ʟ-lactic acid (HA/PLLA) mesh for osteofixation of mandibular sagittal split ramus osteotomy (SSRO), and compared it with that of titanium miniplate. Methods: Patients were divided into resorbable mesh and titanium miniplate fixation groups. A comparative study of the change in the mandibular position was performed with preoperative, 1-day, 6-month, and 2-year postoperative lateral cephalograms. Results: At postoperative 6 months-compared with postoperative 1 day, point B (supra-mentale) was significantly displaced anteriorly in the titanium-fixation group. Moreover, at postoperative 2 years-compared with postoperative 6 months, point B was significantly displaced inferiorly in the titanium-fixation. However, the HA/PLLA mesh-fixation group did not show any significant change with respect to point B postoperatively. Conclusions: The HA/PLLA mesh-fixation group demonstrated superior long-term skeletal stability with respect to the position of mandible, when compared with the titanium-fixation group.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제12권2호
• /
• pp.9-20
• /
• 1990

A series of 19 cases with maxillary hyperplasia and mandibular retrognathia were operated on by simultaneous superior repositioning of the maxilla after Le Fort I osteotomy and anterior repositioning of the mandible after bilateral sagittal split ramus osteotomies with or without osteotomy of the inferior border of the mandible. These were evaluated by retrospective cephalometric and computer analysis for the longitudinal skeletal and dental changes for an average of 17.1 months after surgery. For stabilization of the osteotomized segments, the authors used wire osteosynthesis by means of bilateral infraorbital and zygomatic buttress suspension wire at the maxilla, and direct interosseous wire at the split segments of the mandibular rami. Results show generally good stability after simultaneous maxillary and mandibular surgery with wire osteosynthesis, and a minimal to moderate tendency toward skeletal and dental relapse. This article is a preliminary study to defy the efficiency of the wire osteosynthesis (wo)compared with rigid internal fixation (RIF) for simultaneous maxillary and mandibular surgery. 1. The vertical relapse rate of the A point after superior repositioning of the maxilla is 2.2%. 2. The horizontal relapse rate of the B point after advancement of the mandible is 18.3%. 3. The condyle is distracted inferiorly and slightly posteriorly at the immediate postoperative period. 4. At the long term follow up examination, the condyle presents tendency of return to the preoperative position. 5. Condylar segment angle is decreased at the immediate postoperative period, and at the long term follow up evaluation, the angle is increased. 6. Gonial angle is increased at the immediate postoperative period, and then is decreased at the long term follow up evaluation. 7. The dentition is satisfactory with acceptable movement at the long term follow up evaluation. 8. At the mandibular free body analysis, genioplasty shows good stability. 9. Wire osteosynthesis provides excellent stabilization for the simultaneous maxillary and mandibular surgery.

• 대한치과교정학회지
• /
• 제44권3호
• /
• pp.119-127
• /
• 2014

Objective: To evaluate the long-term effects of self-ligating brackets (SLBs) on transverse dimensions of arches and skeletal and soft tissues and to quantitatively evaluate the treatment outcome after non-extraction treatment with SLBs. Methods: The sample consisted of 24 (18 female and six male) subjects, with a mean age of $14.23{\pm}2.19$ years, who received treatment with the Damon$^{(R)}$3 appliances. Complete records including cephalometric radiographs and plaster models were obtained before treatment (T1), immediately after treatment (T2), six months after treatment (T3), and two years (T4) after treatment. Digital study models were generated. Twenty lateral cephalometric, six frontal cephalometric, and eight dental cast measurements were examined. The Peer Assessment Rating index was used to measure the treatment outcome. The Wilcoxon test was applied for statistical analysis of the changes. Results: There were significant increases in all transverse dental cast measurements with active treatment. There was some significant relapse in the long term, particularly in maxillary width (p < 0.05). Statistically significant increases were found in nasal (p < 0.001), maxillary base, upper molar, lower intercanine, and antigonial (p < 0.05) widths in T1-T2. Lower incisors were proclined and protruded in T1-T2. Conclusions: SLBs correct crowding by mechanisms involving incisor proclination and protrusion and expansion of the dental arches, without induction of clinically significant changes in hard and soft tissues of the face.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제37권
• /
• pp.6.1-6.9
• /
• 2015

Orthognathic surgery requires stable fixation for uneventful healing of osteotomized bony segments and optimal remodeling. Titanium plates and screws have been accepted as the gold standard for rigid fixation in orthognathic surgery. Although titanium osteofixation is the most widely used approach, the use of bioabsorbable devices has been increasing recently. Biodegradation of bioabsorbable devices eliminates the need for a second operation to remove metal plates and screws. However, long-term stability and relapse frequency in bioabsorbable osteofixation are still insufficiently studied, especially in cases of segmental movements of great magnitude or segmental movements to a position where bony resistance exists. This paper reviews the background, techniques, and complications of bioabsorbable osteofixation and compares bioabsorbable and titanium osteofixation in orthognathic surgery in terms of skeletal stability.

• 구강회복응용과학지
• /
• 제22권4호
• /
• pp.271-281
• /
• 2006

Long term prediction of surgical result of skeletal class III has not been evaluated adequately because the stability of orthognathic surgery would be affected by not only set back amount of mandible but also many other factors like skeletal pattern, hyoid position, and airway size. The aimof this study is to discriminate the factors which affect the stability of post-treatment result of surgical outcome of sagittal split ramus osteotomy. We have collected 37 patients (male: 17, female: 20) from patients who have been treated at Orthodontic Department in Dankook University. The patients underwent 3 times Cephalometric X-ray taking at pre-, post-orthognathic surgery and after 12 months retention. The subjects were divided into 2 groups (Stable group: 21, Relapse group: 16) according to their relapse amount. We have taken following results from Students t-test and discriminant analysis. The discriminant factors which discern relapse and stable groupe among treatment change variables were BX and Ba-HY. Hyoid bone moved to posterior and inferior position due to surgery and repositioned superiorly and posteriorly during retention period. Skeletal patterns of the relapse group are smaller mandibular plane angle, anterior mandibular position, and greater distance from hyoid bone to cervical bone and mandible respectively.

• 대한치과의사협회지
• /
• 제50권11호
• /
• pp.682-688
• /
• 2012

Surgery first approach in orthognathic surgery is to proceed the orthognathic surgery without preoperative orthodontic treatment. This approach has many advantages, which include a shorter total treatment period, a high level of patient satisfaction due to immediate post-surgical facial improvement, easy postoperative orthodontic treatment due to early normalization of skeletal muscle, and the rapid tooth movement reflecting the regional accelerated phenomenon. However instability due to transient occlusal interference after surgery make worse of long-term skeletal stability. Especially increasing of vertical occlusion caused by interference of interbicupid and molar happen postsurgical skeletal change. Until now, there is no common consensus about treatment protocol of surgery first approach in orthognathic surgery. The purpose of this paper is to introduce our treatment protocol of the surgery first approach and to evaluate indication and limitation with case analysis.

• 대한치과교정학회지
• /
• 제54권2호
• /
• pp.89-107
• /
• 2024

Objective: This systematic review aimed to provide a comparative analysis of the treatment outcomes, including hard and soft tissues, postoperative stability, temporomandibular disorders (TMD), and quality of life (QoL), in patients with facial asymmetry who underwent orthognathic surgery. Methods: The primary objective was to address the question, "How do different factors related to surgery affect the outcomes and stability of orthognathic surgery in the correction of facial asymmetry?" A meta-analysis was conducted on the outcome parameters, such as skeletal, dental, and soft tissue symmetry, TMD, QoL, and relapse, using the Hartung-Knapp-Sidik-Jonkman method for random-effects models. Subgroup analyses were conducted considering surgery-related factors such as surgical techniques (one-jaw vs. two-jaw), use of the surgery-first approach, utilization of computer simulation, and analytical methods employed to evaluate asymmetry (2D vs. 3D). Results: Forty-nine articles met the inclusion criteria. The metaanalysis demonstrated a significant improvement in the symmetry of hard and soft tissues. The subgroup analysis indicated that the treatment outcomes showed significant improvement, regardless of the factors related to surgery. Changes in TMD signs and symptoms varied according to the surgical technique used. Quality of life improved in the facial, oral, and social domains. Skeletal relapse was observed during the follow-up. Conclusions: Our findings support the positive outcomes of orthognathic surgery in the treatment of facial asymmetry in terms of skeletal and soft tissue improvements, stability, relief of TMD symptoms, and enhancement of QoL. However, most of the included studies showed a low certainty of evidence and high heterogeneity.

• 대한소아치과학회지
• /
• 제42권3호
• /
• pp.270-274
• /
• 2015

성인에서의 임플란트 식립에 관해서는 치료 계획, 술식, 예후 등의 다양한 주제가 연구되어 왔으나 성장기 소아 청소년 환자에서의 임플란트 식립에 대해서는 연구가 제한적이다. 본 종설의 목적은 성장기 환자에서의 임플란트 식립에 대해 논하고 악골 및 치조골의 성장이 임플란트 장기적 예후에 갖는 영향을 살펴보고자 한다. 전반적인 골격성장의 유형에 대해 간략히 살펴보고 실제 임상적 치료법 선택에 대해 고찰하고자 한다.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제32권2호
• /
• pp.126-131
• /
• 2010

Objectives: This study is aimed to determine any differences in the postoperative stability between absorbable and titanium plate systems for fixation in orthognathic surgery with simultaneous maxillomandibular procedures especially including maxillary posterior impaction and advancement. Study Design: Forty patients with dentofacial deformities were randomly assigned into titanium (4 males and 6 females) and absorbable (17 males and 13 females) fixation group. All patients had undergone surgical alterations of maxilla with posterior impaction and advancement. A comparison study of the change in the maxillary position after the simultaneous surgery was performed with 1-day, 6-months postoperative lateral cephalograms compared to preoperative lateral cephalogram by tracing. Wilcoxon rank sum test was used for statistical analysis. Result: The position of the maxilla was stable after surgery and was not changed significantly from 1 day to 6 month after the simultaneous maxillomandibular surgery both in the experimental (absorbable plates) and control (titanium plates). Conclusion: This study suggests that application of absorable plating system in the fixation of maxillary segment in the simultaneous maxillomandibular procedures, leads to a predictable short-term postoperative skeletal stability comparable to the titanium plating system. Long term follow-up and further studies will be needed.

• Imaging Science in Dentistry
• /
• 제54권2호
• /
• pp.181-190
• /
• 2024

Purpose: This study compared sequential changes in skeletal stability and the pharyngeal airway following mandibular setback surgery involving fixation with either a titanium or a bioabsorbable plate and screws. Materials and Methods: Twenty-eight patients with mandibular prognathism undergoing bilateral sagittal split osteotomy by titanium or bioabsorbable fixation were randomly selected in this study. Lateral cephalometric analysis was conducted preoperatively and at 1 week, 3-6 months, and 1 year postoperatively. Mandibular stability was assessed by examining horizontal (BX), vertical (BY), and angular measurements including the sella-nasion to point B angle and the mandibular plane angle (MPA). Pharyngeal airway changes were evaluated by analyzing the nasopharynx, uvula-pharynx, tongue-pharynx, and epiglottis-pharynx (EOP) distances. Mandibular and pharyngeal airway changes were examined sequentially. To evaluate postoperative changes within groups, the Wilcoxon signed-rank test was employed, while the Mann-Whitney U test was used for between-group comparisons. Immediate postoperative changes in the airway were correlated to surgical movements using the Spearman rank test. Results: Significant changes in the MPA were observed in both the titanium and bioabsorbable groups at 3-6 months post-surgery, with significance persisting in the bioabsorbable group at 1 year postoperatively (2.29°±2.28°; P<0.05). The bioabsorbable group also exhibited significant EOP changes (-1.21±1.54 mm; P<0.05) at 3-6 months, which gradually returned to non-significant levels by 1 year postoperatively. Conclusion: Osteofixation using bioabsorbable plates and screws is comparable to that achieved with titanium in long-term skeletal stability and maintaining pharyngeal airway dimensions. However, a tendency for relapse exists, especially regarding the MPA.