|Year : 2021 | Volume
| Issue : 5 | Page : 72-75
Skeletal and soft-tissue stability following advancement genioplasty: A comparative analysis between wire and miniplate osteosynthesis
Ramandeep Singh Brar1, Ritesh Gupta2, Shuchi Gupta3, Kuldeep Chaudhary4, Preeti Singh5, Mandeep Kaur6
1 Department of Oral and Maxillofacial Surgery, Dasmesh Institute of Research and Dental Sciences, Faridkot, Punjab, India
2 Department of Oral and Maxillofacial Surgery, Adesh Institute of Dental Sciences and Research, Bathinda, Punjab, India
3 Department of Prosthodontics and Implantology, Adesh Institute of Dental Sciences and Research, Bathinda, Punjab, India
4 Consultant Prosthodontist, Executive Implant Dental Clinic, S-11 Gamma Shopping Complex, Greater Noida, Gautam, Uttar Pradesh, India
5 Dental Surgeon, Executive Implant Dental Clinic, S-11 Gamma Shopping Complex, Greater Noida, Gautam Buddh Nagar, Uttar Pradesh, India
6 Department of Oral Medicine and Radiology, Dasmesh Institute of Research and Dental Sciences, Faridkot, Punjab, India
|Date of Submission||22-Sep-2020|
|Date of Acceptance||23-Sep-2020|
|Date of Web Publication||05-Jun-2021|
Ramandeep Singh Brar
Department of Oral and Maxillofacial Surgery, Dasmesh Institute of Research and Dental Sciences, Faridkot, Punjab
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Genioplasty has nowadays become a routine procedure in the correction of dentofacial deformities. The present study aimed to evaluate and compare the osseous and soft-tissue stability after advancement genioplasties, stabilized using wire and plate osteosynthesis. Methodology: The study was conducted on ten patients who underwent advanced genioplasty. The patients were divided equally into two groups. In the Group I patients, plates and in Group II, wires were used for stabilization. Lateral cephalograms preoperative and 6 months postoperative were analyzed using Park et al. method of cephalometric analysis. Results: All the ten patients experienced a reliable improvement in esthetics. Although statistically not significant, Group II wire patients have slightly more relapse in the horizontal direction than Group I. The mean ratio of sagittal changes of osseous soft tissue for Group I was 1:0.88 and for Group II wires was 1:0.80. Conclusion: The choice of method of fixation following genioplasty would entirely be based on the merits of the individual cases. The marginal edge of advantage seen in miniplate osteosynthesis when compared to wire osteosynthesis is seen in cases that require larger chin advancements.
Keywords: Genial segment, miniplates, rigid internal fixation, wire
|How to cite this article:|
Brar RS, Gupta R, Gupta S, Chaudhary K, Singh P, Kaur M. Skeletal and soft-tissue stability following advancement genioplasty: A comparative analysis between wire and miniplate osteosynthesis. J Pharm Bioall Sci 2021;13, Suppl S1:72-5
|How to cite this URL:|
Brar RS, Gupta R, Gupta S, Chaudhary K, Singh P, Kaur M. Skeletal and soft-tissue stability following advancement genioplasty: A comparative analysis between wire and miniplate osteosynthesis. J Pharm Bioall Sci [serial online] 2021 [cited 2021 Oct 26];13, Suppl S1:72-5. Available from: https://www.jpbsonline.org/text.asp?2021/13/5/72/317521
| Introduction|| |
The chin, which is one of the most striking facial structures, has long been the object of curiosity, the basis for judging “human character,” and a challenge for the surgeon interested in facial esthetics. The characteristics considered as esthetically pleasing vary according to culture, ethnic type, and even historical period.[1-3] Western society associates certain facial features with an individual's personality. A person with a “weak” or deficient chin may subconsciously be predicted to have a timid, nonathletic, nonaggressive, or indecisive personality, whereas an individual with a “strong” or prognathic chin may be expected to be bold, athletic, aggressive, and decisive. Although the genioplasty is considered a stable procedure, the pull of suprahyoid muscles and premandibular connective tissues attached to the advanced distal segment. This study attempts to compare the skeletal (hard tissue) and soft-tissue stability between plate and wire osteosynthesis after advancement genioplasty.,
| Methodology|| |
This study was conducted on the patients that reported to our unit of Oral, Maxillofacial, and Reconstructive Surgery, Bapuji Dental College and Hospital, Davangere. A total of ten patients were included with an age range between 20 and 25, mean 22.5 (male: female = 2.8). All these patients selected were of chin deficiency anterioposteriorly/vertically, lip incompetency, sloping mentolabial sulcus, and hyperactive mentalis muscle.
Group I included five patients (M:F = 2:3) in which the advanced genial segment was stabilized by use of two 2.0 mm stainless steel 4-holed L-shaped miniplates and 6 mm screws.
Group II included five patients (all females) in which the advanced genial segment was stabilized with 26G stainless steel wires on either side of the midline.
In all the patients, a detailed preoperative assessment was done including case history emphasizing on their expectations on surgical outcome, routine radiographs (orthopantomogram and standardized lateral cephalograms), and photographs.
Under GA, the surgical technique included translabial incision and minimum stripping of the labial soft tissues. The osteotomy was either curvilinear/trapezoidal (box type) using surgical saw/bur. After advancement and stabilization, the wound was closed in layers. Intraoperative antibiotics used were amoxicillin and metronidazole along with a short duration of three doses of dexamethasone 8 mg I. V. Antibiotics were administered for a minimum of 5–7 days.
The preoperative diagnosis of chin deficiency was assessed using Cephalometrics for Orthognathic surgeries analysis by Burstone. A series of lateral cephalograms were taken immediate postoperative (in no more than 1 week), 1 month, 3 months, and 6 months postoperatively. The stability and the ratio of hard to soft tissue were studied by utilizing the landmark of Park et al. method of cephalometric analysis for the chin.
Method of analysis
The evaluation of the three dimensional changes of hard and soft tissues of the chin area after advancement genioplasty was done by Park et al. method cephalometric analysis for the chin [Figure 1] and [Figure 2].
|Figure 1: Dimensional changes of hard and soft tissues of the chin area after advancement genioplasty|
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The landmarks used in this study are
- Occlusal plane (OPL) – A horizontal plane tangent to the uppermost convex area of a definite radiopaque body (dental filling, orthodontic band, or bracket of the most posterior tooth and of the orthodontic bracket of the most anterior tooth region of the mandible
- Menton horizontal plane (MePL) – A horizontal plane that is parallel to OPL and tangent to hard-tissue menton (Me) in the presurgical tracing
- P (Point P; posterior reference point) – A point where the perpendicular line to OPL and MePL crosses the posterior aspect of the inner (lingual) cortex of the symphysis 25 mm below the OPL
- Pg (hard-tissue pogonion)– The most anterior point on the symphysis of mandible tangent to a perpendicular line drawn from OPL
- Pgs (soft-tissue pogonion)– The most anterior point of the soft-tissue chin tangent to a perpendicular line drawn from OPL
- Me (hard-tissue menton) – The most inferior point of the symphysis of the mandible.
The measurements analyzed were as follows
- Horizontal position of the hard-tissue chin – The distance from point P to hard-tissue pogonion (Pg) parallel to OPL
- Horizontal position of the soft-tissue chin – Distance from point P to soft-tissue pogonion (Pgs) parallel to OPL
- Overall horizontal thickness of the soft-tissue chin – The distance from hard-tissue pogonion (Pg) to soft-tissue pogonion (Pgs) parallel to OPL
- Vertical position of anterior aspect of the hard-tissue chin – The perpendicular distance from OPL to hard-tissue pogonion (Pg)
- Vertical position of inferior aspect of the hard-tissue chin – The perpendicular distance from the OPL to MePL
- Vertical position of anterior aspect of soft-tissue chin – The perpendicular distance from OPL to soft-tissue pogonion (Pgs).
The displacement of the above mentioned points resulting after surgery was derived by calculating the difference between preoperative and the immediate postoperative, 1 month postoperative, and 6 months postoperative positions. The immediate postoperative film was not used for calculation of the soft-tissue changes because of the presence of edema.
| Results|| |
In Group I (miniplate osteosynthesis) – A total of five patients, wherein two patients who were diagnosed as retrogenia and increased lower one-third facial height underwent vertical reduction and sliding advancement genioplasty, whereas the other three patients who were diagnosed as retrogenia alone underwent trapezoidal advancement genioplasty (box genioplasty).
In Group II (wire osteosynthesis)– A total of five patients, only one patient who was diagnosed as retrogenia and increased lower one-third facial height underwent vertical reduction and sliding advancement genioplasty procedure.
The overall horizontal change at the end of 6 months at hard-tissue pogonion for Group I (plate) was 4.6 + 0.5 mm. The overall average horizontal change at the end of 6 months at soft-tissue pogonion was 3.9 + 0.5 mm. When compared the ratio of hard tissue to soft tissue, change was 1:0.88.
In Group II (wires), the overall average horizontal change at the end of 6 months at hard-tissue pogonion was 4.2 + 0.6 mm. The overall average horizontal change at the end of 6 months at soft-tissue pogonion was 3.4 + 1.0 mm. The ratio of hard to soft tissue changes was found to be 1:0.80. Although the relapse in horizontal direction (backward movement) is seen slightly more in wire group in comparison to the plate group, the difference is found to be statistically insignificant. One patient in Group I showed the 1:1 hard to soft tissue response at the end of 6 months [Table 1].
|Table 1: Postoperative changes in the horizontal and vertical measurements in two groups|
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| Discussion|| |
The rationale for patients undergoing genioplasty was very distinctive and complex. Some of the important factors are reimbursement of functional defect, as well as social and psychological reasons, although the primary reason is esthetic.
The osteotomy of the inferior border of the mandible can be adversely affected by two completely different mechanisms in same manner as any other maxillofacial osteotomy. First of all is the skeletal instability, in which the advanced genial segment changes its position before osseous union, so rapidly altering the surgical outcome. The second one being osseous remodeling, in which the advanced genial segment is slowly recontoured during the remodeling process, and this is much slower pathway leading to different final results from the immediate postsurgical outcome. These two mechanisms are important in advancement genioplasty carried out by the osteotomy of the inferior border of the mandible.,
In general, changes occur in the horizontal position of landmark pogonion due to bone remodeling. In our study, as remodeling occurred pogonion moved further downward, but did remain in the same anteroposterior position. This remodeling pattern is not atypical, but the maintenance of the horizontal position of pogonion is most likely due to skeletal stability achieved by the method of fixation.,,
The mandible is a dense bone and a continuous blood circulation is provided by soft-tissue pedicle, where by the significant resorption, the advanced genial segment is prevented. However, the aforementioned concept has changed considerably during the past 20 years; the pattern of bone remodeling that occurs in the chin following advancement by osteotomy of the inferior border of the mandible is now a very well-established phenomenon. However, the cause is still not known. Various theories have been put forward (1) soft-tissue pedicle size and existence or absence of it, (2) periosteal and soft-tissue compression, and (3) postoperative stretching of the suprahyoid musculature. All of them are concerned with blood supply to the advanced genial segment. Nevertheless, it has been seen that even with use of a broad soft-tissue pedicle, bone remodeling occurs invariably.[9-12]
In our results, the sagittal change of hard-tissue pogonion was minimal during the 6-month follow-up period, but vertical change occurred mainly between 1 and 3 months postoperatively and changed more between 3rd and 6th months. These results recommend that sharp superior edge of the osseous segment created by surgery undergoes rapid resorption and remodeling between 3rd and 6th months following surgery, although the advanced genial segment had a broad soft-tissue pedicle. The remodeling patterns of the advanced segment do not exhibit inferior rotation of bodily displacement in the postoperative evaluation in both the groups of our study. The fixation devices must be placed in the areas of bone deposition.
The ratio of sagittal change of osseous/soft tissue ranges from 1:0.6 to 1:1. Mild variations seen in our study may be attributed to scar contracture seen in the postoperative period. Only the mentalis muscle is significant during the surgical approach to genioplasty as it provides lip's predominant vertical support. If this muscle is either not functional or not precisely repositioned following surgery, the outcome may be extremely unesthetic because of chin ptosis or “witch's chin” and possible lip incompetency.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]