Long-term stability of isolated advancement genioplasty, and influence of associated risk factors: A systematic review

Optimizing Esthetic Outcomes and Bone Stability: Chin Advancement Through Inverted V Osteotomy

Traditional horizontal osteotomies for small and short chins often yield suboptimal results due to limited bone advancement, resulting in deep labiomental folds and heightened bone resorption risks. This study investigates the effectiveness of an innovative inverted V-shaped osteotomy technique in enhancing esthetic outcomes for patients with such chin concerns. Thirty-eight patients who underwent inverted V-shaped osteotomy for recessed chins between January 2018 and June 2022 were included. Excluding cases involving simultaneous mandibular contouring surgery, patients were followed up for a median duration of 1.2±0.5 years. Preoperation and postoperation soft tissue pogonion (Pg') and labiomental fold depth (LMF) changes were measured. IBM SPSS (version 27.0) was used for statistical analysis, with significance defined as P<0.05. Patient satisfaction was assessed using a visual analog scale. Successful advancement genioplasty was performed on all patients without any severe complications. The average change in soft tissue pogonion (Pg') measured 6.2 (1.9) mm, and the mean alteration in labiomental depth was 0.42 (0.4) mm. The procedure achieved a bone to soft tissue movement ratio of 1:0.96. Patient satisfaction was notably high, with a mean VAS score of 8.7. An inverted V-shaped osteotomy enables greater bone advancement for small and short chins, leading to improved esthetic outcomes and offering a mechanically advantageous condition for bone segments.

Exploring the relationship between the number of systematic reviews and quality of evidence: an orthognathic surgery-based study

OBJECTIVE

We analyzed the quality and quantity of systematic reviews (SRs) of orthognathic surgery, the most frequently published topic in maxillofacial surgery.

STUDY DESIGN

We searched the PubMed database for SRs of orthognathic surgery with no restriction on the language of publication date. We assessed the certainty of evidence presented according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol and the Leiden Manifesto using the Grading of Recommendations Assessment, Development, and Evaluation approach. We analyzed the data using descriptive statistics, Pearson´s correlation test, and linear regression.

RESULTS

Of the 171 SRs evaluated, approximately one fifth presented evidence with a high level of certainty. The number of orthognathic surgery SRs has been increasing, and many SRs were published after very similar topics had already been published. There is no relationship between the impact factor and the certainty of evidence.

CONCLUSIONS

An excessive number of SRs of orthognathic surgery are published, and many SRs are superfluous, simply reporting previous findings. Clinicians should not base treatment decisions solely on the evidence presented in SRs, and journal editors and reviewers should evaluate these SRs more critically, particularly when they address topics that have already been covered in the literature.

Skeletal stability after mandible bilateral sagittal split osteotomy - comparison of patient-specific implant and mini-plate fixation: A retrospective study

The aim of the study was to compare the stability of the virtual surgical planning (VSP) and computer-aided design accompanied by patient-specific implants (PSIs) and conventional mini-plates in mandible advancement with bilateral sagittal split osteotomy (BSSO). This retrospective study evaluates the clinical and cephalometric records of 53 patients (12 male, 41 female) treated with BSSO in Helsinki University Hospital. Subjects were divided into two groups: VSP-PSI (21 patients: 4 male and 17 female; mean age 38 years, range 25-53 years); and conventional wafer-based repositioning with mini-plate fixation (32 patients: 8 male and 24 female; mean age 39 years, range 21-56 years). The effect of the amount and direction of the advancement on the stability was also analysed individually. The standardized lateral cephalometric radiographs in three time points were analysed to compare the groups. After surgery (T2), there were no differences between groups in cephalometric variables. During follow-up (T2-T3), the cephalometric variables in both Groups A and B were stable, so there was no difference in stability between the VSP-PSI and the conventional mini-plate groups. During follow-up, the mandibles rotated clockwise or counterclockwise, relapsed towards their original direction, and the changes were statistically significant (jaw relationship; p = 0.018, soft tissue profile; p = 0.025); when the advancement of mandible was >6 mm, the increase in gonial angle compared to mandibles advanced ≤6 mm was statistically significant (p = 0.03). VSP-PSI and conventional mini-plate fixation can be considered equally stable. Large advancements with counterclockwise rotation regardless of fixation method are more susceptible to relapse. VSP-PSI alone cannot solve the relapse-related concerns in mandible osteotomy.

Influence of differences in mandibular incisor inclination on skeletal stability after orthognathic surgery in patients with skeletal Class III malocclusion

OBJECTIVE

The preoperative inclination angle of mandibular incisors was crucial for surgical and postoperative stability while the effect of proclined mandibular incisors on skeletal stability has not been investigated. This study aimed to evaluate the effects of differences in presurgical mandibular incisor inclination on skeletal stability after orthognathic surgery in patients with skeletal Class III malocclusion.

METHODS

A retrospective cohort study of 80 consecutive patients with skeletal Class III malocclusion who underwent bimaxillary orthognathic surgery was conducted. According to incisor mandibular plane angle (IMPA), patients were divided into 3 groups: retroclined inclination (IMPA < 87°), normal inclination (87° ≤ IMPA < 93°) and proclined inclination (IMPA ≥ 93°). Preoperative characteristics, surgical changes and postoperative stability were compared based on lateral cephalograms obtained 1 week before surgery (T0), 1 week after surgery (T1), and at 6 to 12 months postoperatively (T2).

RESULTS

The mandible demonstrated a forward and upward relapse in all three groups. No significant differences in skeletal relapse were observed in the 3 groups of patients. However, the proclined inclination group showed a negative overbite tendency postoperatively compared with the other two groups and a clinically significant mandibular relapse pattern. Proclined IMPA both pre- and postoperatively was correlated with mandibular relapse.

CONCLUSION

Sufficient presurgical mandibular incisor decompensation was of crucial importance for the maintenance of skeletal stability in patients with skeletal Class III malocclusion who subsequently underwent orthognathic surgery.

Bone healing and stability after advancement genioplasty using a pre-bent absorbable plate and screws

This study aimed to compare the bone healing and stability of the chin with a pre-bent absorbable plate and a manually bent absorbable plate after advancement genioplasty. Patients with class II malocclusion who underwent genioplasty with bimaxillary surgery were included. After genioplasty, two absorbable bicortical screws were fixed on both sides. Then, a pre-bent absorbable plate and screws were used in the center area to fix the segment in advancement genioplasty (PB group). A manually bent absorbable plate was used for the remaining patients (MB group). Computed tomography (CT) was performed before surgery and 1 week and 1 year after surgery. Changes in the pogonion (Pog) and menton (Me) points, soft tissue points, and the ratio of bone squares under the plate were evaluated using lateral cephalometric images reconstructed with 3-dimensional CT data. 32 patients were included in the study. There were no significant differences in the cephalometric measurements in the time interval from 1 week to 1 year. However, the bone square ratio in the PB group showed a significant increase after 1 year (P = 0.0021). Within the limitations of the study it seems that the use of a pre-bent absorbable plate is effective in promoting bone healing after advancement genioplasty.

Hard and Soft Tissue Relapse After Different Genioplasty Procedures: A Scoping Review

The chin is a crucial component of facial aesthetics, and 20% of craniofacial problems require repair of the chin size, shape, and position. Genioplasty is used to treat irregularities in all three planes of the chin. Specific hard and soft tissue relapses following various genioplasty techniques have not been adequately studied in the literature to date. The purpose of this scoping review was to investigate the stability of hard and soft tissue changes achieved by different genioplasty procedures, six months after the procedure. A literature search was performed on PubMed, Web of Science, Embase, Wiley Online, Scopus, Google Scholar, Science Direct, and Cochrane databases from January 1, 2011 to October 31, 2022. Prospective and retrospective cohorts, case-control studies, observational studies, and randomized control trials, with at least 10 patients, which were written in English and evaluated the stability of different genioplasty procedures, with a follow-up period of at least six months were included. The manual and electronic search yielded 523 articles, and after complete screening, seven articles were selected (five with advancement genioplasty and two with reduction genioplasty) that met the eligibility criteria for review. The patients undergoing reduction genioplasty had a mean age of 24.15 years, compared to 20.5 years for augmentation genioplasty. The average follow-up period was 18.64 months for augmentation genioplasty and 10.5 months for reduction genioplasty technique. The relapse was assessed at pogonion, and it was noted that the average surgical advancement at hard tissue pogonion was 7.04 mm with a relapse of 0.69 mm after six months post-treatment. The average vertical movement of the hard tissue pogonion was 1.8 mm with a relapse of 0.74 mm. The average reduction at hard tissue pogonion was 3.2 mm in the vertical direction with a relapse of 0.2 mm and 0.8 mm reduction in soft tissue pogonion with a relapse of 0.3 mm. The soft to hard tissue ratio mentioned in the different studies ranged from 0.89 to 0.97. Both reduction and augmentation genioplasty are stable and reliable for altering the chin position for aesthetic purposes. The recommended mode of fixation is rigid fixation.

Surgical techniques used in chin feminization: Literature review and knowledge update

Genioplasty is commonly performed as part of facial feminization surgery. Commonly addressed areas in facial feminization surgery include the chin. According to some authors, 100% of patients request genioplasty surgery in order to feminize their faces. Specific genioplasty techniques (involving generally reduction surgery) applied to transgender patients have been rarely described in the literature. Objective: We aimed to carry out a review of the literature to update the current knowledge on this subject while achieving a comprehensive synthesis of the available surgical techniques for reduction genioplasty in trans Male to Female patients. Conclusion: Reduction genioplasty is frequently performed in facial feminization surgery. Multiple surgical techniques for chin feminization have been described in the existing literature. Reduction genioplasty requires combined work in the sagittal and transverse planes so as to obtain a harmonious result. However, no comparative study on the different surgical techniques has as yet been conducted. Patient satisfaction or surgical complications (which tend to be rare) cannot be related to any specific surgical technique.

Systematic mapping review of orthognathic surgery

STUDY DESIGN

Systematic mapping review AIM AND SCOPE: The objective of this mapping review was to identify, describe, and organize clinical research currently available from systematic reviews and primary studies regarding co-interventions and different surgical modalities used in orthognathic surgery (OS) and their outcomes.

METHODS

Systematic reviews (SRs), randomized controlled trials, and observational studies that evaluated perioperative OS co-interventions and surgical modalities were identified in an exhaustive search of MEDLINE, EMBASE, Epistemonikos, Lilacs, Web of Science, and CENTRAL. Grey literature was also screened.

RESULTS

Included were 35 SRs and 253 primary studies, 103 from SRs, and another 150 identified in our search. Overall, SR quality was rated as critically low, with only two SRs rated as of high quality. 19 questions on population, interventions, comparisons, and outcomes (PICO) extracted from the SRs focused on osteosynthesis methods, surgical cutting devices, and use of antibiotics, corticosteroids, and induced hypotension. Also identified were 15 research gaps. Evidence bubble maps were created to graphically depict the available evidence.

CONCLUSION

Future high-quality research, both primary and secondary, is needed to address the knowledge gaps identified in this systematic mapping review.

Retrospective study of long-term hard and soft tissue stability after advancement genioplasty with the use of rigid osteosynthesis

The main objective of this study was to evaluate long-term stability of rigid osteosynthesis in the context of advancement genioplasty. Bone stability was defined as a long-term bone loss of less than 2 mm. Measurements were performed on lateral cephalograms, in the sagittal and vertical planes, at three times: preoperative (T0, less than one month before surgery), early postoperative (T1, at least one month post-operatively) and late postoperative (T2, at least one year after surgery). 25 patients were included in the study, with a mean follow-up of 3.47 years (range 1-9.42 years). The mean sagittal bone advancement at T1 was 4.06 mm ± 1.34, with a bone loss of 0.65 mm at T2 (p = 0.001). The mean vertical bone movement was 1.25 mm ± 0.47 at T1, with a relapse at T2 of 0.34 mm (p = 0.27). The soft-to-hard tissue ratio was 78% in the sagittal plane. Rigid osteosynthesis offers long-term stability, with very little change in clinical outcome, in advanced genioplasty.