Orthognathic Surgery Treatment Need in a Turkish Adult Population: A Retrospective Study

Investigation of orthognathic surgery indicators-combination with index of orthognathic functional treatment needs (IOFTN) and maxillofacial morphometric analysis

PURPOSE

The aim of this retrospective study was to determine orthognathic surgery indicators for Japanese patients with jaw deformities using both Index of Orthognathic Functional Treatment Needs (IOFTN) and maxillofacial morphometric analysis.

SUBJECTS AND METHODS

The subjects were 89 patients treated with orthognathic surgery and 92 patients treated with orthodontic treatment alone, and were classified as class I, II, or III according to the ANB angle. Based on the results for IOFTN and the results of cephalometric analysis, the indication criteria for orthognathic surgery were examined.

RESULTS

In IOFTN analysis, none of patients in the orthognathic surgery group were classified as category 1 or 2, while 48% of the patients in the orthodontic treatment group were classified as category 4 or 5. The results of the cephalometric analysis of patients in classified categories 4 and 5 showed that the orthognathic surgery group had significantly greater lateral mandibular deviation in Class I cases, significantly more severe degree of mandibular retrusion in Class II cases, and significantly more severe degree of mandibular prognathism in Class III cases. The results of the logistic regression analysis showed that IOFTN was a common variable as an indication criterion for orthognathic surgery, and several different variables were also selected from the cephalometric measurements in each group.

CONCLUSION

IOFTN is a highly sensitive and useful indicator as a criterion for orthognathic surgery. However, in the choice of treatment strategy, maxillofacial morphometric analyses and the patient's desired goal are important.

Changes in occlusion after orthognathic surgery: a systematic review and meta-analysis

PURPOSE

This study aims to systematically review and identify the changes of occlusion in patients after orthognathic surgery.

METHODS

The protocol was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) and was registered to the International Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD42021253129. Studies included were Original articles only, Additionally, studies were included if the outcome of occlusal force was measured pre- and postoperatively and if occlusal forces resulted from a long follow-up of a minimum of 1 year following orthognathic surgery using adequate measurement tools. Non-English articles, case reports, case series, and non-original articles, including systematic reviews and literature reviews, were excluded.

RESULTS

The search strategy yielded a total of 978 articles. Of the 978 articles, 285 were duplicates. After reading the titles and abstracts, 649 articles were excluded, and full-text articles of the remaining 47 studies were reviewed independently by two authors for eligibility wherein 33 articles were excluded, because they did not meet the inclusion criteria. Finally, a total of 14 studies were processed for critical review.

CONCLUSION

The occlusal force increased after orthognathic surgery, although not to the level of the control group; however, the maximal bite force remained unchanged. Immediately after orthognathic surgery, chewing and swallowing forces increased. Significant reductions in the postoperative occlusal contact pressure areas was also observed.

Systematic Review and Meta-Analysis of the Index of Orthognathic Functional Treatment Need for Detecting Subjects with Great Need for Orthognathic Surgery

Index of Orthognathic Functional Treatment Need (IOFTN) Identifies patients with greatest need for orthoganthic surgery. This systematic review looks into the available evidence on prevalence of patients with great treatment need (IOFTN 4&5) who had orthognathic surgery in previous studies. Literature search of the major electronic databases was carried out for articles published between 2014 and September 2023, looking for "Index of Orthognathic Functional Treatment Need","Orthognathic Surgery","IOFTN", "Epidemiology" and "Dentofacial Deformity". The prevalence of patients identified with IOFTN grades of 4&5 was calculated. A random-effect model was employed and the Forest and Galbraith plots were produced. The pooled prevalence estimate for subjects with IOFTN scores of 4&5 was calculated. The heterogeneity among studies was assessed with the I2 statistics. In total, 14 retrospective studies conducted between 2015 and 2019 in 7 countries (UK, New Zealand, Iran, Pakistan, Turkey, Malaysia, Japan) were included, reporting on 1339 orthognathic patients. The sample sizes ranged from 30 to 200. Only 7 studies reported on the subcategories of the IOFTN for grades 1, 2&3. The prevalence of orthognathic patients with IOFTN scores of 4 & 5 ranged from 79% to 100%. The heterogeneity I2 statistics was 16%. The pooled prevalence estimate for subjects with IOFTN scores of 4&5 was 92% (95% CI, 0.91-0.94%). According to this meta-analysis, IOFTN successfully identified 92% of patients who underwent orthognathic surgery with a great need for treatment (Grade 4 & 5). To enhance the identification of patients with well-compensated malocclusions, previous orthodontic treatment, or extreme occlusal deviations (e.g., proclination or retroclination of incisors), it would be advantageous to employ additional means alongside IOFTN for assessing orthognathic need in this group.

Effectiveness of low-intensity laser photobiomodulation in reducing inflammatory events (pain, edema, and trismus) after orthognathic surgery: a systematic review and meta-analysis of randomized clinical trials

OBJECTIVE

This systematic review aimed to answer whether, in (P) individuals undergoing orthognathic surgery, (I) low-level laser therapy (LLLT) during or shortly after the surgical procedure compared to (C) pharmacologic therapy alone or no therapy for improvement of post-intervention complications relieves (O) postoperative inflammatory events in (S) randomized clinical trials.

MATERIAL AND METHODS

A preliminary electronic search was conducted for references with language following a Latin (Roman) alphabet in seven databases index, and gray literature without restriction on language or publication period. Risk of bias was performed by RoB 2.0 tool, and meta-analysis used mean differences (MD) for edema and mouth opening and standardized mean differences (SMD) for pain scores (p < 0.05, Revman®).

RESULTS

A total of 91 control patients and 114 LLLT patients were included. The wavelengths ranged from 660 to 940 nm, and the applied energy density was between 5 and 100 J/cm2 at mostly extraoral distributed points. LLLT significantly reduced edema (MD =  - 4.27, CI95% - 5.13 to - 3.41 mm) in the period from 5 days to 2 weeks postoperatively (p < 0.001) and showed strongly reduced pain scores (SMD =  - 1.37, I95% =  - 1.99 to - 0.75) between 1 day and 5 weeks (p < 0.001), without significantly interfering with mouth opening (p = 0.110). Despite the low risk of bias, high heterogeneity among studies (I2 > 70%) and small sample sizes made the certainty of GRADE evidence low.

CONCLUSION

This SR demonstrated that LLLT effectively controls pain and edema after orthognathic surgery.

CLINICAL RELEVANCE

Systematic review that summarizes the use of photobiomodulation on orthognathic surgery.

Effect of Maxillary Expansion Treatment Protocols On Maxillary Sinus Volume, Pharyngeal Airway Volume, and Hyoid Bone Position: A Prospective, Cone Beam Computed Tomography (CBCT) Study

Aim:

This study aimed to investigate the changes in maxillary sinus volume, pharyngeal airway volume, and hyoid bone position in patients treated with Rapid Maxillary Expansion (RME) and Alternate Rapid Maxillary Expansion and Constriction (AltRaMEC) – Facemask therapy and compare between the groups.

Materials and Methods:

The records of 15 patients between the age group of 8-14 years with Class I and Class III malocclusion were collected, and the patients were assigned into two groups. The first group comprised of 8patients (4 girls and 4 boys) who were treated with Rapid Maxillary Expansion. The second group comprised 7 patients (5 boys and 2 girls) treated with expansion devices using Alt-RaMEC protocol followed by maxillary protraction using a facemask. Pre and post-treatment CBCT scans were obtained and analyzed for changes in the pharyngeal airway, maxillary sinus volume, and hyoid bone position. The maxillary sinus volume was calculated in 3 dimensions by measuring the craniocaudal height, anteroposterior depth, and mediolateral width. Measurements were taken before and after the procedure to compare the groups and between the groups. The data were analyzed using Paired t-test and an Independent t-test.

Results:

In the RME group, a significant increase in the total maxillary sinus volume (mean difference = 520±576.57mm3), especially in the craniocaudal height, was seen, but no changes were noted in the pharyngeal airway and hyoid position. The AltRAMEC group showed a statistically significant increase in the maxillary sinus volume (anteroposteriorly) and nasopharyngeal volume with a p-value <0.005. Comparing the maxillary sinus volume changes in RME and AltRAMEC groups showed a statistically significant increase in the volume of the maxillary sinuses in both groups, significantly higher in the RME group.

Conclusion:

RME and AltRAMEC protocol followed by facemask therapy caused a significant increase in the maxillary sinus volume, while no changes were noted in the nasopharynx, oropharynx, hypopharynx, and hyoid bone position. While comparing the treatment effects between the groups, RME showed a greater increase in maxillary sinus volume (p < 0.05), specifically in the anteroposterior dimension. Since there are no changes in airway volume and hyoid position with the skeletal expansion protocols, there will be no difference in nasal resistance to airflow.

Accuracy of Segmented Le Fort I Osteotomy with Virtual Planning in Orthognathic Surgery Using Patient-Specific Implants: A Case Series

Background: When maxillary transversal expansion is needed, two protocols of treatment can be used: a maxillary orthodontic expansion followed by a classical bimaxillary osteotomy or a bimaxillary osteotomy with maxillary segmentation. The aim of this study was to assess the accuracy of segmented Le Fort I osteotomy using computer-aided orthognathic surgery and patient-specific titanium plates in patients who underwent a bimaxillary osteotomy for occlusal trouble with maxillary transversal insufficiencies. Methods: A virtual simulation of a Le Fort I osteotomy with maxillary segmentation, a sagittal split ramus osteotomy, and genioplasty (if needed) was conducted on a preoperative three-dimensional (3D) model of each patient’s skull using ProPlan CMF 3.0 software (Materialise, Leuven, Belgium). Computer-assisted osteotomy saw-and-drill guides and patient-specific implants (PSIs, titanium plates) were produced and used during the surgery. We chose to focus on the maxillary repositioning accuracy by comparing the preoperative virtual surgical planning and the postoperative 3D outcome skulls using surface superimpositions and 13 standard dental and bone landmarks. Errors between these preoperative and postoperative landmarks were calculated and compared to discover if segmental maxillary repositioning using PSIs was accurate enough to be safely used to treat transversal insufficiencies. Results: A total of 22 consecutive patients—15 females and 7 males, with a mean age of 27.4 years—who underwent bimaxillary computer-assisted orthognathic surgery with maxillary segmentation were enrolled in the study. All patients presented with occlusion trouble, 13 with Class III malocclusions (59%) and 9 (41%) with Class II malocclusions. A quantitative analysis revealed that, overall, the mean absolute discrepancies for the x-axis (transversal dimension), y-axis (anterior−posterior dimensions), and z-axis (vertical dimension) were 0.59 mm, 0.74 mm, and 0.56 mm, respectively. The total error rate of maxillary repositioning was 0.62 mm between the postoperative cone-beam computed tomography (CBCT) and the preoperatively planned 3D skull. According to the literature, precision in maxilla repositioning is defined by an error rate (clinically relevant) at each landmark of <2 mm and a total error of <2 mm for each patient. Conclusions: A high degree of accuracy between the virtual plan and the postoperative result was observed.

Management of A Bad Split Complication: A Systematic Review

Introduction:

Bad split is one of the well-known intra-operative complications that occur during the bilateral sagittal split osteotomy (BSSO) procedure, which is a rehabilitation procedure for patients with mandibular deformities. The prevention of further post-surgery complications required sufficient management of bad split complications.

Objective:

This study aimed to analyze the management of bad split complications during a BSSO procedure.

Methods:

The literature review was conducted in the form of library research in the field of bad split complications' management by a BSSO based on the Preferred Reporting Items for Systematic Reviews (PRISMA). Related studies were found through using a manual search using Pubmed, ScienceDirect, Ebscohost, Scopus, Medline, Embase, and Web of Science, among other search engines. The inception of incorporation standards, the process of data extraction, and the determination of the risk of bias were carried out by the authors. The process of data screening was conducted by applying the inclusion and exclusion criteria.

Results:

This paper systematically reviewed seven related studies, four of which were case series and two of which were cross-sectional. The utilization of additional osteosynthetic plates was revealed throughout the extraction process as the most acquainted course of action to manage the bad split complications during the BSSO procedure.

Conclusion:

The osteosynthetic plate and miniplate application with bicortical or monocortical screws were exposed as the most used treatment for bad split complications.

Long-term hard and soft tissue response following isolated genioplasty: a systematic review

PURPOSE

Genioplasty facilitates alteration of the chin position and contour which contributes to aesthetics and function. The response of the hard and soft tissues following genioplasty has not been assessed after a year or more of the surgery being performed. Hence, the aim of this systematic review was to assess the response of the hard and soft tissues occurring at least 1 year after the procedure.

MATERIAL AND METHODS

A literature search was conducted in the following electronic databases: PubMed, Ovid, LILACS, and Cochrane Library. Potential articles were identified wherein only studies with genioplasty performed as an isolated procedure and with data at least 12 months after the procedure were included.

RESULTS

Five studies were included in this systematic review. Two of the articles included were considered to be of good quality while three were considered to be of moderate quality using a modified Downs and Black tool. The ROBINS-I tool showed a moderate risk of bias for most domains. The study characteristics revealed varying degrees of relapse for the hard and soft tissues.

CONCLUSIONS

In the anteroposterior plane, the soft tissue relapsed more than the hard tissues 3 years post genioplasty. However, relapse in the vertical plane showed a wide variation for both the hard and soft tissues. In the anteroposterior plane, the hard tissue to soft tissue response 2 years or more following genioplasty ranged from 1:0.77 to 1:0.91 while in the vertical plane the hard tissue to soft tissue response ranged from 1:0.67 to 1:1.16.

Comparison of one-jaw and two-jaw orthognathic surgery in patients with skeletal Class III malocclusion using data from 10 multi-centers in Korea: Part I. Demographic and skeletodental characteristics

Objective

To investigate demographic and skeletodental characteristics of one-jaw (1J-OGS) and two-jaw orthognathic surgery (2J-OGS) in patients with skeletal Class III malocclusion.

Methods

750 skeletal Class III patients who underwent OGS at 10 university hospitals in Korea between 2015 and 2019 were investigated; after dividing them into the 1J-OGS (n = 186) and 2J-OGS groups (n = 564), demographic and skeletodental characteristics were statistically analyzed.

Results

2J-OGS was more frequently performed than 1J-OGS (75.2 vs. 24.8%), despite regional differences (capital area vs. provinces, 86.6 vs. 30.7%, p < 0.001). Males outnumbered females, and their mean operation age was older in both groups. Regarding dental patterns, the most frequent maxillary arch length discrepancy (ALD) was crowding in the 1J-OGS group (52.7%, p < 0.001) and spacing in the 2J-OGS group (40.4%, p < 0.001). However, the distribution of skeletal pattern was not significantly different between the two groups (all p > 0.05). The most prevalent skeletal patterns in both groups were hyper-divergent pattern (50.0 and 54.4%, respectively) and left-side chin point deviation (both 49.5%). Maxillary spacing (odds ratio [OR], 3.645; p < 0.001) increased the probability of 2J-OGS, while maxillary crowding (OR, 0.672; p < 0.05) and normo-divergent pattern (OR, 0.615; p < 0.05) decreased the probability of 2J-OGS.

Conclusions

In both groups, males outnumbered females, and their mean operation age was older. The most frequent ALD was crowding in the 1J-OGS group, and spacing in the 2J-OGS group, while skeletal characteristics were not significantly different between the two groups.

Scleral exposure changes after Le Fort I maxillary advancement with vertical component in individuals with skeletal Class III malocclusion-A stereophotogrammetric image study

OBJECTIVE

This retrospective study aimed to evaluate inferior scleral exposure changes in Class III patients that underwent orthognathic surgery with Le Fort I osteotomy with and without vertical displacement.

MATERIALS AND METHODS

Preoperative and 6-months postoperative cephalograms and stereophotogrammetric images of 45 subjects (mean age:21.66±2.97 years) that underwent orthognathic surgery for Class III correction were retrieved. Subjects were divided into 3 groups: maxillary advancement-only (AO); maxillary advancement+impaction (AI), maxillary advancement+downfracture (AD). Exclusion criteria were mandibular-only surgery, occlusal canting, facial asymmetry, orbital surgery, and craniofacial syndrome. One investigator measured inferior scleral exposure on both sides using following landmarks: upper eyelid margin (A), inferior limbus (B) and lower eyelid margin (C). Distance between A and C was recorded as overall eye height (E), distance between B and C was recorded as inferior sclera exposure (S). S:E ratio in percentage was calculated to standardize sclera exposure relative to overall eye height. Wilcoxon signed-rank and Kruskal Wallis tests were used for statistical analysis (p<0.05).

RESULTS

Mean value of maxillary movements were: 4.21±1.82mm advancement in AO; 5.08±2.18mm advancement and 2.33±0.99mm impaction in AI; 3.95±1.45mm advancement and 3.1±0.71mm downfracture in AD. Change in reduction of scleral exposure was significant in all groups (p<0.05). AI group bilaterally and AO group right side had highest differences (-4.96±4.86, -6.09±4.21, -4.99±3.23, respectively). There was no significant difference between groups in S:E ratio changes (p>0.05).

CONCLUSION

Intergroup comparisons showed no statistically significant difference, revealing similar reduction in all three groups despite the differences in the vertical movement variable.

Current Trends in Orthognathic Surgery in Poland—A Retrospective Analysis of 124 Cases

The analysis aims at assessing the current trends in orthognathic surgery. The retrospective study covered a group of 124 patients with skeletal malocclusion treated by one team of maxillofacial surgeons at the University Hospital in Zielona Góra, Poland. Various variables were analysed, including demographic characteristics of the group, type of deformity, type of osteotomy used, order in which osteotomy was performed and duration of types of surgery. The mean age of the patients was 28 (ranging from 17 to 48, SD = 7). The group included a slightly bigger number of females (59.7%), with the dominant skeletal Class III (64.5%), and asymmetries were found in 21.8% of cases. Types of osteotomy performed during surgeries were divided as follows: LeFort I, segmental LeFort I, BSSO, BSSO with genioplasty, LeFort I with BSSO, LeFort I with BSSO and genioplasty, segmental LeFort I with BSSO, isolated genioplasty. Bimaxillary surgeries with and without genioplasty constituted the largest group of orthognathic surgeries (49.1%), and a slightly smaller percentage were one jaw surgeries (46.7%). A statistically significant correlation was found between the type of surgery and the skeletal class. In patients with skeletal Class III, bimaxillary surgeries were performed significantly more often than in patients with skeletal Class II (57.5% vs. 20.0%; p = 0.0002). The most common type of osteotomy in all surgeries was bilateral osteotomy of the mandible modo Obwegeser–Epker in combination with Le Fort I maxillary osteotomy (42.7%). The order of osteotomies in bimaxillary surgeries was mandible first in 61.3% of cases. The longest surgery was bimaxillary osteotomy with genioplasty (mean = 265 min), and the shortest surgery was isolated genioplasty (mean = 96 min). The results of the analysis show a significant differentiation between the needs of orthognathic surgery and the types of corrective osteotomy applied to the facial skeleton.

Masticatory muscle function affects the pathological conditions of dentofacial deformities

The causes of dentofacial deformities include various known syndromes, genetics, environmental and neuromuscular factors, trauma, and tumors. Above all, the functional effects of muscles are important, and deformation of the mandible is often associated with a mechanical imbalance of the masticatory muscles. With the vertical position of the face, weakness of the sling of the masseter muscle and medial pterygoid muscle causes dilatation of the mandibular angle. In patients with a deep bite, excessive function of the masticatory muscles is reported. Myosin heavy chain　(MyHC) properties also affect jawbone morphology. In short-face patients, the proportion of type II fibers, which are fast muscles, is high. The proportions of muscle fiber types are genetically determined but can be altered by postnatal environmental factors. Orthognathic surgery may results in the transition of MyHC to type II (fast) fibers, but excessive stretching enhances the release of inflammatory mediators and causes a shift toward a greater proportion of slow muscle fibers. This feature can be related to postoperative relapse. Bones and muscles are in close crosstalk, and it may be possible to use biochemical approaches as well as biomechanical considerations for the treatment of jaw deformities.

Novel Sub-Clustering of Class III Skeletal Malocclusion Phenotypes in a Southern European Population Based on Proportional Measurements

Current phenotypic characterizations of Class III malocclusion are influenced more by gender or ethnic origin than by raw linear skeletal measurements. The aim of the present research is to develop a Class III skeletal malocclusion sub-phenotype characterization based on proportional cranial measurements using principal component analysis and cluster analysis. Radiometric data from 212 adult subjects (115 women and 96 men) of southern European origin affected by Class III skeletal malocclusion were analyzed. A total of 120 measurements were made, 26 were proportional skeletal measurements, which were used to perform principal component analysis and subsequent cluster analysis. The remaining 94 supplementary measurements were used for a greater description of the identified clusters. Principal component analysis established eight principal components that explained 85.1% of the total variance. The first three principal components explained 51.4% of the variance and described mandibular proportions, anterior facial height proportions, and posterior-anterior cranial proportions. Cluster analysis established four phenotypic subgroups, representing 18.4% (C1), 20.75% (C2), 38.68% (C3), and 22.17% (C4) of the sample. A new sub-clustering of skeletal Class III malocclusions that avoids gender influence is provided. Our results improve clinicians' resources for Class III malocclusion and could improve the diagnostic and treatment approaches for this malocclusion.

Comparison of Profile Attractiveness between Class III Orthodontic Camouflage and Predictive Tracing of Orthognathic Surgery

Objective

The aim of this study was to compare the profile attractiveness between orthodontic camouflage of the Class III malocclusion and the predictive tracing simulating orthognathic surgery evaluated by dentists and laypeople. Settings and sample population. The sample consisted of 21 patients (9 male; 12 female) with Class III malocclusion treated with orthodontic camouflage and Class III intermaxillary elastics. Material and Methods. The mean initial age of the patients was 24.38 years (SD 3.32), and the mean ANB angle was −1.91° (SD 0.83°). Patients presented skeletal Class III and normal growth patterns. Initial and final lateral cephalograms of each patient were used. The initial cephalogram was used to perform the treatment simulation of orthognathic surgery, and its silhouette was compared to the silhouette obtained from the final cephalogram after Class III orthodontic camouflage. A subjective analysis of profile attractiveness was performed by 47 laypeople and 60 dentists, with scores from 1 (less attractive) to 10 (most attractive). Mann–Whitney tests were used to compare profile attractiveness between the orthodontic treatment and the predictive tracing groups and between dentists and laypeople.

Results

The predictive tracing of orthognathic surgery showed to be statistically significantly more attractive (mean score 4.57, SD 2.47) than that of the Class III camouflage orthodontic treatment (mean score 4.22, SD 2.40), with a mean numerical but significant difference of 0.35 (SD 2.01) (P < 0.001). Laypeople were more critical than dentists in evaluating profile attractiveness, but numerical difference between the groups was also small.

Conclusion

The profile silhouette of predictive tracing simulating orthognathic surgery showed to be more attractive than that of Class III camouflage orthodontic treatment; however, differences were small but statistically significant. Laypeople showed to be more critical than dentists.