Orthodontic anchorage without negative reciprocal influences on tooth position can be achieved by the use of immobile implants. An existing dentition permits placement of endosseous implants in only a few regions. These are the edentulous parts of the ridge due to previous extractions, the ascending ramus of the mandible, and the os palatinum. A precondition for successful implant osseointegration is a satisfactory bone base. The midline of the os palatinum is of particular anatomic interest due to the increasing use of anchorage implants in this area. Even though most implants are incorporated uneventfully, in some cases, the osseointegration of these implants fails. Therefore, anatomic data characterizing the palatal midline region are of clinical importance. In this study, trephine bur biopsies provided the material for histologic facings. The donor age covered a span from 12 to 53 years and illustrated that complete ossification of the suture palatina mediana (SPM) is rare before the age of 23 years. Therefore, especially in adult orthodontic treatment, the use of palatal implants should be considered. The anterior SPM is less often ossified than the posterior region. Implant placement should take this into account and consider that a bone bed more favorable to osseointegration might be found posterior to the interconnecting line of the first premolars.
The skeletal anchorage system (SAS) consists of titanium anchor plates and monocortical screws that are temporarily implanted in either the maxilla or the mandible as absolute orthodontic anchorage. With SAS, anterior open bite can be improved by the counterclockwise rotation of the mandible, accompanied by the intrusion of molars. The present study was designed to evaluate treatment and posttreatment dentoalveolar changes following the intrusion of mandibular molars. Nine adult open bite patients (7 women and 2 men) successfully treated with SAS were included in the following study. The amount of intrusion, relapse, and dentoalveolar changes were measured on cephalometric radiographs, panoramic radiographs, and dental casts. The results of this study were as follows: (1) the average amount of intrusion of the mandibular first and second molars was 1.7 mm and 2.8 mm, respectively; (2) the average relapse rates were 27.2% at the first molars and 30.3% at the second molars; (3) there were no significant changes in crestal bone heights, clinical crown length, or root length; and (4) counterclockwise rotation of the mandible and decrease of anterior facial height were observed during treatment. Thus, it was concluded that SAS would be a valid modality to intrude mandibular molars for correction of open bite.
The impact of dental and skeletal movements on the soft tissues during orthodontic and surgical treatments is widely known. Most studies are limited to examining the repercussions of a dental or skeletal movement on a given soft tissue point. The uniqueness of the present study, carried out on 95 patients, lies in the examination of the impact of movements of various landmarks--2 dental points (incision superius and incision inferius) and 4 skeletal points (anterior nasal spine, point A, point B, andpogonion)--on 7 soft tissue landmarks (from the tip of the nose to soft tissue pogonion). The study was carried out with the purpose of providing a simple, practical, and accurate tool for clinical use to assist in treatment planning. This article outlines the main aspects of the tool while specifying its limitations and error margins.
Many 3-dimensional (3D) techniques have been utilized to register and analyze the face in 3 dimensions, but each system has its own merits and disadvantages. C3D is a relatively new 3D imaging system that was developed to capture the 3D geometry of the face. Landmark identification on 3D facial models is facilitated by a software-based facial analysis tool developed by the authors. The reproducibility of landmark identification was high for 20 of the chosen points (standard deviations of repeated placements of landmarks around their centroids were 0.5 mm or less). The method is useful in studying facial soft tissue changes following orthognathic surgery and other types of facial surgery, as well as assessing facial soft tissue growth and development of the craniofacial complex.
Treatment of dentofacial deformities with jaw osteotomies has an effect on airway anatomy, and therefore, mandibular setback surgery has the potential to diminish airway size. The purpose of this study was to evaluate the long-term effect of mandibular setback surgery on the airway size. The material consisted of pre- and postoperative (minimum 1 year) lateral radiograms of 22 individuals (18 females and 4 males) with a mean age of 30 years, who had undergone mandibular setback surgery to correct skeletal Class III discrepancies. Hard and soft tissue points were digitized with a Numonics Accugrid digitizer and analyzed with Xmetrix software. A paired t test was used to evaluate the difference between pre- and postoperative measurements. In addition, Pearson's coefficient correlation was calculated to reveal the possible association between the skeletal change in relation to the change in airway size. The mean value for the initial SNA was 81.3 degrees, 85.4 degrees for SNB, 36.9 degrees for S-Na/MP, and for the posterior airway, 10.5 mm and 12.0 mm retropalatinally and retrolingually, respectively. At the postoperative evaluation, SNB was 80.7 degrees, S-Na/MP 41.0 degrees, and the posterior airway retropalatinally 8.3 mm and retrolingually 9.8 mm. Statistical analysis revealed a highly significant correlation between the change in the ANB angle and in the S-Na/MP angle versus the change in the upper airway size, both retropalatinally and retrolingually. Mandibular setback surgery with posterior rotation may gradually result in increased upper airway resistance in cases where neuromuscular adaptation is insufficient to compensate for the reduction in the airway size. Therefore, large anteroposterior discrepancies should be corrected by combined maxillary and mandibular osteotomies.
Vertical asymmetry of the maxilla can determine the inclination of the occlusal plane and result in a lack of internal reference points usually employed to measure surgical movements. Maxillary repositioning is therefore based upon surgical planning, which is commonly elaborated on dental casts and model surgery. The absolute precision of surgical planning is not guaranteed by dental casts and model surgery, and the intraoperative assessment of maxillary repositioning is considered to be of paramount importance in such cases. This article describes a simple, noninvasive intraoperative technique that is useful in measuring the vertical dimension of the maxilla and helps to indicate precise repositioning. It illustrates the technique and reports the results obtained in a series of 30 patients treated surgically for maxillomandibular malformations with vertical asymmetries and occlusal plane inclination from January to December 2000 at the Maxillofacial Surgery Department of "La Sapienza" University in Rome, Italy.
The Le Fort I osteotomy results in predictable long-term effects. The soft tissues, however, can be difficult to control because of considerable variation in their adaptation. Several adverse reactions can take place, including thinning and lateral retraction of the lip, accentuation of the nasolabial groove, reduced vermilion exposure, and increase of the nasolabial angle. In this study on 51 selected patients, the V-shaped wound in the vestibule of the maxilla after the Le Fort I osteotomy was closed with a "Y," with the bast of the "Y" in the midline of the upper lip (V-Y closure). Forward multiple regression analysis was calculated for each bony landmark. Regression equations were formulated if P < .05. The equation with the bony point with the highest r2 value was considered the most important independent variable. The selected independent variables were used to form 4 subgroups with identical vectors of movements: impaction, advancement, impaction and advancement, and dorsal impaction. In these 4 subgroups, forward multiple regression analysis was used to select equations with the highest r2 value (P < .05). The selected equations demonstrated that a V-Y plasty as single soft tissue procedure suffices only in advancement cases, and only if the nose does not need additional upward rotation. In the other 3 subgroups, additional procedures are necessary, such as alar cinch suture, reduction of the anterior nasal spine, or grinding of the paranasal area in order to prevent the above-mentioned adverse soft tissue changes.
The psychologic profile of 100 consecutive patients undergoing orthognathic surgery for correction of Class II or Class III malocclusion was monitored in a prospective observational study. Patients and their relatives or friends completed questionnaires about their self-image before surgery, 6 weeks postoperatively, and 6 months postoperatively. Preoperatively, patients with Class III malocclusion felt significantly less attractive (P = .03), had slightly higher attention to physical appearance, and had slightly stronger feelings of insecurity regarding their facial appearance compared with Class II patients. Grading of attractiveness/self-confidence improved significantly in Class III patients at 6 weeks postoperatively (P = .006), while in Class II patients the improvement was less pronounced and only significant at 6 months postoperatively (P = .002). Grading of attractiveness/self-confidence by relatives/friends of patients with Class II and Class III was similar preoperatively, but was significantly higher for Class III patients 6 weeks postoperatively in comparison with Class II patients (P = .048). These data indicate that the psychologic profiles are significantly different between Class II and Class III patients preoperatively and show different dynamics postoperatively.
Anterior maxillary osteotomy is frequently applied to skeletal Class II cases with maxillary protrusion. In addition to the anteroposterior problem, these cases are often accompanied with a long midfacial appearance and display of incisors and gingiva during smiling. In the application of anterior maxillary osteotomy to such patients, it is necessary to move the anterior maxillary segments upward as well as backward. Since the upward movement occasionally interferes with the intranasal endotracheal tube, orotracheal intubation is recommended for the operation. Recently, the use of a resin replica of the mandibular dental arch was introduced to place the anterior maxillary segment correctly in the planned position and to obtain the correct occlusion. This article reports on 3 maxillary protrusive skeletal Class II patients with deep overbites and vertical esthetic problems treated by this method. The treatment results show that all 3 patients exhibited large upward and backward movements of the anterior maxillary segments and desirable facial profiles, with a reduction of the deep overbites after the treatment. This case report demonstrates that the anterior maxillary osteotomy under orotracheal intubation with the use of a resin replica is a useful method to treat maxillary protrusive skeletal Class II patients with a large alveolar height.
The purpose of this retrospective study was to analyze the accuracy of computer predictions by CASSOS (Computer-Assisted Simulation System for Orthognathic Surgery) 2001 software (2000 SoftEnable, Technology). Forty adult patients who had undergone orthognathic surgery were evaluated. Pre- and postsurgical lateral cephalographs were scanned into the computer, and 71 landmarks for each cephalograph were digitized. Digitization error was assessed from repeated digitizations. A customized cephalometric analysis consisting of 14 measurements was used in this study. Predicted and actual postsurgical hard tissue landmarks were compared using the Student t test. Results showed good correlation between repeated digitization for all measurements. There were no statistically significant differences in 10 of the 14 measurements. The differences that were statistically significant were in angular measurements for SNA angle, upper incisor to maxillary plane angle (U1-MxP), interincisal angle (U1-L1), and upper incisor to anterior cranial base angle (U1-SN). The greatest mean difference measured was the interincisal angle (U1-L1) which, although statistically significant, was clinically insignificant. This investigation showed that CASSOS 2001 software provides accurate hard tissue prediction for orthognathic surgical procedures.
A 10-year longitudinal evaluation of the morphology (size and shape) of hard tissue palate was performed in 6 female and 6 male healthy adults (mean age at the second evaluation was 33 years, SD = 2.2). All subjects had a complete permanent dentition, including the second molars, and were free from respiratory problems. Palatal landmarks were digitized with a computerized 3D instrument, and their coordinates were used to derive a mathematical model of palatal form. Palatal shape (size-independent) was assessed by a fourth-grade polynomial in the sagittal and frontal plane projections. Palatal dimensions in the frontal and sagittal planes were computed and compared between the 2 evaluations by paired Student t tests. A great variability was observed, and no significant modifications in size were found (P > .05 for all variables). No variations in shape were observed. Sex had no significant effect for any variable (Student t for independent samples, P > .05). This study showed that in healthy subjects, hard tissue palatal morphology does not seem to change between the third and the fourth decades of life.
The purpose of this study was to determine if a general consensus exists among orthodontists regarding the features of an adequate presurgical setup. A questionnaire was developed to assess the importance of 12 criteria for surgical readiness. Each criterion was rated on a 5-point scale (1 = Unimportant, 5 = Critical). This questionnaire was sent to 104 randomly selected, board-certified orthodontists in the United States and Puerto Rico. Usable questionnaires were returned by 57 respondents (55% response rate). The highest and most consistent ratings were given for Arch Compatibility in the transverse dimension (mean = 4.66, SD = 0.55), Crossbite (mean = 4.57, SD = 0.63), and Torque of the Anterior Teeth (mean = 4.38, SD = 0.73). Further analysis showed a correlation between surgical experience of the orthodontist and a higher rating of importance for Torque of the Mandibular Teeth (Spearman r = 0.38), Torque of the Maxillary Teeth (Spearman r = 0.37), and Torque of the Anterior Teeth (Spearman r = 0.28). These results suggest that as orthodontists gain surgical experience, they attribute more importance to correcting the torque of the teeth. Also, the relatively large differences in opinion regarding presurgery orthodontic setup support a need for further research and/or educational effort regarding what criteria are important before surgery.
To determine the distribution of costs and various influencing factors in the entire process of surgical-orthodontic treatment in community hospital care, a retrospective study was carried out. The records and radiographs of 99 community hospital patients operated on between 1994 and 2001 were included. Cost analysis data were gathered from 4 phases of treatment: the orthodontics, the surgical outpatient assessments, the surgery/surgeries, and the inpatient period. The results showed that the surgical phases together are responsible for roughly 61% of the costs, 28% of which were attributed to the surgical operation itself. Orthodontics made up approximately 39% of the total costs, with an average of 26 visits. The average total costs of all treatments were US $6,206 +/- 912. Patients that could be operated on with bilateral sagittal split ramus osteotomy of the mandible only had the lowest costs, and those who required bimaxillary osteotomies had the highest costs. Of the several clinical and cephalometric measurements made in this study, only skeletal open bite and orthodontic space closure after tooth extraction were found to affect the costs. It can be concluded that surgical-orthodontic treatment is a rather expensive way to correct dentofacial malocclusions due to the high costs of the surgical phase. Skeletal open bite constituted the most costly entity, while malocclusion resulting from mandibular deformity was the cheapest.
The aim of this study was to register and assess the accuracy of the superimposition method of a 3-dimensional (3D) soft tissue stereophotogrammetric image (C3D image) and a 3D image of the underlying skeletal tissue acquired by 3D spiral computerized tomography (CT). The study was conducted on a model head, in which an intact human skull was embedded with an overlying latex mask that reproduced anatomic features of a human face. Ten artificial radiopaque landmarks were secured to the surface of the latex mask. A stereophotogrammetric image of the mask and a 3D spiral CT image of the model head were captured. The C3D image and the CT images were registered for superimposition by 3 different methods: Procrustes superimposition using artificial landmarks, Procrustes analysis using anatomic landmarks, and partial Procrustes analysis using anatomic landmarks and then registration completion by HICP (a modified Iterative Closest Point algorithm) using a specified region of both images. The results showed that Procrustes superimposition using the artificial landmarks produced an error of superimposition on the order of 10 mm. Procrustes analysis using anatomic landmarks produced an error in the order of 2 mm. Partial Procrustes analysis using anatomic landmarks followed by HICP produced a superimposition accuracy of between 1.25 and 1.5 mm. It was concluded that a stereophotogrammetric and a 3D spiral CT scan image can be superimposed with an accuracy of between 1.25 and 1.5 mm using partial Procrustes analysis based on anatomic landmarks and then registration completion by HICP.
Skeletal stability and temporomandibular joint (TMJ) signs and symptoms were analyzed in 23 patients in whom mandibular protrusion and mandibular deviation had been corrected using bilateral sagittal split ramus osteotomy (BSSRO group, n = 10) and unilateral SSRO and intraoral vertical ramus osteotomy (USSRO+IVRO group, n = 13). Miniplate fixation was used in SSRO but no fixation was used in IVRO. The ratio of condylar bony change was 30.4% (7/23) and all condylar bony changes were seen on the deviated side. All preoperative signs and symptoms of TMJ disorders (4/13 patients in the USSRO+IVRO group and 2/10 patients in the BSSRO group) disappeared after surgery. Comparing the USSRO+IVRO group and the BSSRO group, in patients without condylar bony change, the mandible in both groups was stable anteriorly and horizontally after surgery, even though there was a larger horizontal mandibular movement in the USSRO+IVRO group during surgery. Comparing patients with condylar bony change versus no condylar bony change in the USSRO+IVRO group, postoperative horizontal mandibular displacement was significantly larger in the condylar bony change group than in the no condylar bony change group. These results support the idea that USSRO+IVRO can be useful in correcting mandibular deviation as well as improving signs and symptoms of TMJ disorders. However, it also seems important to be aware of the possibility of horizontal mandibular relapse in patients with condylar bony change.
The gingival crevicular fluid (GCF) flow rate and composition vary according to the condition of the periodontal tissues. The levels of some of its constituents have been shown to correlate with the actual clinical measurements of periodontal disease progression and reflect changes occurring deep in the periodontium. During the course of orthodontic treatment, the forces exerted produce a distortion of the periodontal ligament extracellular matrix, resulting in alterations in cellular shape and cytoskeletal configuration. Such events lead to the synthesis and presence in the deeper periodontal tissues of extracellular matrix components, tissue-degrading enzymes, acids, and inflammatory mediators; induce cellular proliferation and differentiation; and promote wound healing and tissue remodeling. These changes may modify both the GCF flow rate and its components. Consequently, analysis of GCF samples may provide a better understanding of the biochemical processes associated with tooth movement and may help the clinician make therapeutic choices based on qualitative and quantitative information.
In this paper preliminary results are presented of a prospective study designed to examine the effect of maxillary fixation methods on postoperative stability. The purpose of this study was to evaluate the stability of Le Fort I osteotomy stabilized with semirigid fixation of the maxilla (SRMF) or rigid fixation of the maxilla (RMF). All patients had skeletal Class III malocclusion and underwent bimaxillary surgery (Le Fort I maxillary advancement with or without superior repositioning and bilateral sagittal split osteotomies of the mandible). Standardized cephalometric analysis was performed on serial radiographs of 42 patients immediately before surgery, 1 week after surgery, after release of fixation, and 1 year postoperatively. The patients were randomized into 2 treatment groups: 23 patients received RMF (group A), and 19 patients received SRMF (group B). Within the groups, patients showed good stability with regard to their baseline characteristics. To show the therapeutic equivalence of the 2 treatments, analysis of the recorded data followed the approach for an equivalence trial. The mean surgical advancement was 5.34 +/- 1.50 mm for group A and 4.51 +/- 1.37 mm for group B. The mean amount of postsurgical relapse was 0.98 +/- 1.27 mm for group A and 0.30 +/- 1.04 mm for group B. Group A patients experienced 93% of their relapse (0.92 mm) during fixation, while group B patients experienced 96% of their relapse (0.29 mm) after release of fixation. RMF provided better stability than SRMF for all maxillary landmarks in the vertical plane. All considered points both in horizontal and vertical plane exhibited full equivalence for 95% confidence intervals, which seems to indicate equivalent stability between the surgical procedures.
Modern orthognathic surgery is said to be clean contaminated due to the intraoral means of access. Complications after orthognathic surgery, a common operation, occur about 10% of the time. Actinomycosis, a rare specific infection, plays a negligible role. Diagnostically, it should be differentiated from other infections that occur a long time after the operation. Three cases of actinomycosis that occurred after orthognathic surgery were observed, and therapeutic measurements are described case by case.
The purpose of this study was to investigate the postoperative satisfaction of orthognathic surgery patients and related factors. The authors assessed 108 orthognathic surgery patients using the Minnesota Multiphasic Personality Inventory and the Symptom Checklist 90 preoperatively. The degree of deformity, expectations for surgery, and support of significant others were also evaluated before surgery. The patients were given questionnaires at 4 time points, from 10 days to 1 year after surgery. A multiple regression test was used to analyze the relative importance of psychologic factors and other variables in explaining the degree of patients'satisfaction with surgery. Postoperative satisfaction was high and increased with time. Patients with more education and more severe deformities reported greater satisfaction. During the early stage after surgery, patients with a high degree of interpersonal sensitivity, whose close relatives did not support surgery, or who accepted surgery passively tended to be more dissatisfied. Patients who had realistic expectations were more satisfied in the long term. Complications such as pain and swelling influenced patients' satisfaction soon after surgery, whereas the responses of people around the patients influenced their satisfaction at all stages postoperatively.
