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Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis
YIJOM-3504; No of Pages 5
Int. J. Oral Maxillofac. Surg. 2016; xxx: xxx–xxx http://dx.doi.org/10.1016/j.ijom.2016.09.006, available online at http://www.sciencedirect.com
Clinical Paper Dental Implants
Changes in the lower lip soft tissue after bone graft harvesting from the mandibular § symphysis
N. Altiparmak1, B. S. Akdeniz2, S. S. Akdeniz1, S. Uc¸kan3 1
Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Baskent University, Ankara, Turkey; 2Department of Orthodontics, Faculty of Dentistry, Baskent University, Ankara, Turkey; 3Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Medipol University, Istanbul, Turkey
N. Altiparmak, B. S. Akdeniz, S. S. Akdeniz, S. Uc¸kan: Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis. Int. J. Oral Maxillofac. Surg. 2016; xxx: xxx–xxx. # 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Abstract. Following the surgical release of the mentalis muscle, lip incompetence and/or an increase in lower incisor exposure may be seen due to undesirable attachment of the muscle fibres. The aim of this study was to evaluate the extent of lip ptosis, lower incisor exposure, and other soft tissue changes following bone graft harvesting from the mandibular symphysis when the mentalis muscle is reapproximated precisely to its original position. Seventeen consecutive patients who underwent bone graft harvesting from the mandibular symphysis were included in this study. The mentalis muscle was isolated, identified, marked, and reapproximated precisely during the bone harvesting operation. Digital lateral cephalograms obtained preoperatively and at 6 months postoperative were analyzed and compared by paired samples t-test to determine the horizontal and vertical soft tissue changes in the lower lip and chin. Although the soft tissue thickness at soft tissue point B and at soft tissue pogonion had increased significantly at 6 months after chin bone graft harvesting, there were no significant changes in lower incisor exposure or other positional alterations of the lower lip (P < 0.05). Precise reattachment of the mentalis muscle in its original position helps to avoid significant vertical positional changes in the lower lip. Increases in soft tissue thickness can be observed following bone graft harvesting from the mandibular symphysis.
§ This study was accepted as an oral abstract at the 22nd International Conference on Oral and Maxillofacial Surgery, held in Melbourne, Australia, 27–31 October 2015.
0901-5027/000001+05
Alveolar ridge augmentation is a routine procedure performed by clinicians so that implants of the desired width and length can be inserted.1 The autogenous bone grafts for alveolar ridge augmentation are commonly harvested from intraoral
Keywords: lower incisor exposure; chin ptosis; lower lip ptosis; bone graft harvesting. Accepted for publication 8 September 2016
donor sites such as the mandibular ramus and symphysis. Bone graft harvesting from the mandibular symphysis has been reported to be a reliable procedure that offers easy access and an adequate bone tissue volume for grafting.2 However,
# 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Altiparmak N, et al. Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis, Int J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.ijom.2016.09.006
YIJOM-3504; No of Pages 5
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previous studies on this subject have reported certain soft tissue changes due to the release of the mentalis muscle during the graft harvesting procedure.3,4 The mentalis muscle is the only muscle that is exposed during the surgical approach for symphysis bone graft harvesting.5,6 It is the sole elevator of the lower lip and chin.5 Although there are no fibres that pass into the lower lip, the mentalis muscle also provides major vertical support to the lower lip.5–8 The surgical approach to the osteotomy site when harvesting a bone graft from the symphysis necessitates degloving most of the chin and detachment of the mentalis muscle. If the mentalis muscle is either not functioning or not precisely repositioned after surgery, the result may be extremely unaesthetic because of possible chin ptosis and lip incompetence. Careful reapproximation of the mentalis muscle during flap closure is recommended to avoid these complications.8 Most previous studies on the mandibular symphysis bone graft harvesting procedure have focused on the bone graft itself rather than the neighbouring soft tissues. Lip and chin contour alterations following mandibular symphysis bone grafts have been evaluated previously, with several changes in the vertical plane reported. It has been suggested that further studies are needed to assess the alterations in the soft tissues, such as the lip and chin, after the bone graft block has been harvested from the donor area.3 However information is still missing on the soft tissue changes following a mandibular symphysis bone graft harvesting procedure that enables precise repositioning of the mentalis muscle during closure of the surgical flap. The aim of this study was to compare vertical and sagittal profile changes in the lower lip and chin following mandibular symphysis bone graft harvesting with precise reattachment of the mentalis muscle during closure of the mucoperiosteal flap.
Patients who had undergone previous operations for bone harvesting from the same field, Bone-related systemic diseases such as osteoporosis, which could alter bone remodelling, Patients who received orthodontic treatment during the study, Patients whose central incisors and/or first molars were missing, Patients who received restorations on their first molars or incisors during the study.
device (VarioSurg 50/60 Hz; NSK, Tochigi, Japan). Corticocancellous bone grafts were harvested by straight or inclined osteotomies. No grafts or biomaterials were used to fill the bony defects at the donor sites. The soft tissue closure was completed in two stages. First the mentalis muscle layer was closed by initial marking material with two horizontal mattress sutures, and then the mucosa layer was sutured with 3-0 Vicryl suture material with a simple suturing technique. Measurement methods
Surgical methods
All surgical procedures were performed under local anaesthesia by the same oral and maxillofacial surgeon. Local anaesthetic (4 ml 2% lidocaine with 1:200,000 epinephrine) was administered along the mucosal incision line and mental foramen point for bleeding and pain control. A superficial incision was made through the lower labial mucosa with a scalpel, leaving at least 5 mm of non-keratinized mucosa superiorly between the bilateral lower cuspids. Subsequently, a sub-mucosal incision was made to expose the mentalis muscle. Following the mentalis muscle dissection, the lower and upper ends of the muscle were marked with 3-0 resorbable suture material to suture the muscle in its original position, in accordance with the technique described by Chaushu et al.8 (Fig. 1). Periosteal incision and mucoperiosteal dissection were performed with the marker sutures left on both edges of the muscle fibres. The bilateral mental nerves were identified and protected during the creation of the mucoperiosteal flap. Periosteal attachment of the mental protuberance was preserved in all patients. The osteotomy was performed at least 5 mm below the root apices and 5 mm away from the mental foramen with a piezoelectric surgical
Digital lateral cephalograms were obtained preoperatively and at 6 months postoperative using standardized techniques and equipment. Pre- and postoperative cephalometric tracings and measurements of vertical and sagittal parameters were performed, as shown in the study of No´ia et al.3 Adobe Photoshop Version 13.0 software (Adobe Systems Inc., San Jose, CA, USA) was used for the cephalometric measurements. The vertical parameters measured were lower incisor exposure (LIE), vertical position of the anterior point of the lower lip (VLi), vertical point of the soft tissue point B (VB0 ), vertical point of the soft tissue pogonion (VPg0 ), and lower lip length (LLi) (Fig. 2a). The sagittal parameters measured were lower lip thickness (LLT), soft tissue thickness at soft tissue point B (SB0 ), soft tissue thickness at pogonion (SPg0 ), and the mento-labial angle (MLA) (Fig. 2b). Statistical analysis
The statistical analysis was performed using IBM SPSS Statistics version 21.0 software (IBM Corp., Armonk, NY, USA). A Shapiro–Wilk test of normality verified the normal distribution of the data. Pre- and postoperative measurements were compared using the paired samples t-test with the significance level of P < 0.05.
Materials and methods
Seventeen consecutive adult patients who underwent a mandibular symphysis bone graft harvesting procedure were included in this study. Thirteen were female and four were male, and their mean age was 42.5 9.7 years. All were American Society of Anesthesiologists (ASA) category I. All procedures were performed between January and June 2014. Exclusion criteria were as follows:
Fig. 1. (a) Blunt dissection of the bilateral mentalis muscles. (b) The origin and insertion edges of the mentalis muscle marked with 3-0 resorbable suture material before incision of the muscle fibres.
Please cite this article in press as: Altiparmak N, et al. Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis, Int J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.ijom.2016.09.006
YIJOM-3504; No of Pages 5
Lower lip soft tissue after bone graft harvesting
Fig. 2. (a) The vertical parameters evaluated: lower incisor exposure (LIE), vertical position of the anterior point of the lower lip (VLi), vertical point of the soft tissue point B (VB0 ), vertical position of the soft tissue pogonion (VPg0 ), and lower lip length (LLi). (b) The sagittal parameters evaluated: lower lip thickness (LLT), soft tissue thickness at soft tissue point B (SB0 ), soft tissue thickness at pogonion (SPg0 ), and mento-labial angle (MLA).
Results
The mean changes and statistical differences in parameters measured pre- and postoperatively are shown in Table 1. Although minor increases in LIE (0.9 mm), VLi (0.5 mm), and VB0 (0.7 mm), and minor decreases in VPg0 (0.3 mm) and LLi (0.3 mm) were observed, analysis of the collected data showed that there were no statistically significant changes in any of the vertical parameters. The changes in LIE values are shown in a graph in Fig. 3. While there were statistically significant increases in soft tissue thickness at soft tissue point B and soft tissue pogonion (0.9 and 1.7 mm, respectively), no other sagittal measurement changed significantly (P < 0.05). Bone defects at the osteotomy sites were still distinctly visible in some of the 6-month follow-up cephalograms (Fig. 4). Discussion
Precise reattachment of the mentalis muscle led to minimal changes in LIE and the soft tissue profile.
The mentalis muscles are unique because no other muscles of the chin are incised during stripping of the chin, and once they are incised, their original position is re-established once the periosteum has regained its place.5 A few previous studies have shown that the releasing of the mentalis muscle during symphysis osteotomy increases LIE, which might cause an unaesthetic surgical outcome and might also lead to the patient looking older due to a sagging appearance.3,8,9 The mentalis muscle buttresses the soft tissue of the chin directly and the lower lip indirectly. The fibres of the mentalis muscle pass from their origin inferiorly into the skin of the chin at the level of the soft tissue prominence. The most superior fibres are the shortest and pass almost horizontally into the skin, while the lower fibres are the longest and pass vertically. The origin of the mentalis muscle determines the labial sulcus depth. It is recommended by various researchers that the mentalis muscle is precisely sutured in its original place in order to prevent ptosis resulting from poor positioning or elongation of the muscle.10,11 Two possible reasons are given by Chaushu et al. for ptosis
Table 1. Pre- and postoperative mean values and their statistical comparison. Variable
Preoperative
Postoperative
P-value
LIE VLi VB0 VPg0 LLi LLT SB0 SPg0 MLA
2.24 8.79 20.16 32.09 45.59 16.17 11.34 12.92 127.64
3.19 9.22 20.88 31.64 45.24 15.83 12.23 14.61 128.17
0.10 0.54 0.12 0.65 0.54 0.62 0.034a 0.025a 0.87
LIE, lower incisor exposure; VLi, vertical position of the anterior point of the lower lip; VB0 , vertical point of soft tissue point B; VPg0 , vertical point of soft tissue pogonion; LLi, lower lip length; LLT, lower lip thickness; SB0 , soft tissue thickness at soft tissue point B; SPg0 , soft tissue thickness at pogonion; MLA, mento-labial angle. a Statistically significant difference (P < 0.05).
3
related to detachment of the mentalis muscle.8 The first is reattachment of the muscle inferiorly and the second is failing to reattach the muscle in its exact original position.8 Chaushu et al. evaluated the vertical and horizontal alterations in the labium and chin region related to ptosis of the mentalis muscle in 30 patients who underwent an osseous genioplasty.8 In the control group, the mentalis muscle was not marked and the muscle was repositioned via conventional suturing method, while in the experimental group the upper and lower parts of the mentalis muscle were marked and it was placed precisely into its original position during flap closure.8 The researchers emphasized the need for exact determination, proper isolation, and marking of the muscle during mucosal flap elevation in order to reposition it in its original place. They reported that the alterations in profile of the soft tissue were not significant when the mentalis muscle was reattached in its original place.8 No´ia et al. performed a prospective study on patients who underwent mandibular symphysis bone graft harvesting and evaluated the soft tissue alterations in the lower lip and chin.3 They reported that LIE increased 1.7 mm and that the vertical position of the vermilion increased 1.3 mm, which were both statistically significant increases and different from the changes seen in the present study. The most likely reason for this difference is that they did not mark the mentalis muscle during the mucosal flap releasing, and the increase in the appearance of the lower incisors was a result of ptosis of the labium and ptosis of the mentalis muscle. The increase in LIE is an undesired aesthetic result. Therefore, vertical positional alterations of the lower lip can have a serious negative effect on facial aesthetics. The results of the study of No´ia et al. are consistent with those obtained for the control group in the study by Chaushu et al.8 Both studies concluded that the postoperative soft tissue contour alterations at this site resulted from a failure to suture the detached mentalis muscle in its exact original position, rather than to the bone graft harvest. In order to prevent this, both researchers draw attention to the proper isolation, remarking, and suturing of the mentalis muscle in its original position.3,8 Three types of intraoral incision are commonly used for graft harvesting from the mandibular symphysis: sulcular, marginal, and alveolar.11–14 The alveolar mucosal incision was used in the present study to avoid introducing errors caused
Please cite this article in press as: Altiparmak N, et al. Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis, Int J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.ijom.2016.09.006
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Fig. 3. Preoperative and postoperative values of lower incisor exposure (LIE).
Fig. 4. Lateral cephalometric radiographs of a patient, used in the study: (a) preoperative, and (b) 6 months postoperative. Note the remaining bone defect caused by the graft harvesting operation marked with an arrow. (c) Best-fit superimposition of the pre- and postoperative lateral cephalometric tracings showing the increase in soft tissue thickness at soft tissue point B and pogonion.
by variations in methods. Following the mucosal incision, the mentalis muscle was exposed and the upper and lower edges of the mentalis muscle were marked before the muscle incision, as recommended by Chaushu et al.8 Thus the muscle fibres were sutured to their original position after graft harvesting. No significant alteration in labium profile was observed in the vertical plane in this study, while the soft tissue thickness at soft tissue point B and pogonion was increased in the sagittal plane. Similarly, No´ia et al. reported that the soft tissue thickness increased approximately 2 mm at soft tissue supramentale and pogonion.3 The soft tissue thickness increase at 6 months postoperative was possibly a result
of tissue enlargement into the donor graft cavity during the bone healing period; it did not have a significant effect on the aesthetics of the lower third of the face. Although there was no statistically significant change in LIE in the current study, a mean increase of 0.9 mm in LIE could be seen as an important clinical change. Future studies should focus on further decreasing the amount of contraction of the muscle and LIE. This study has two limitations. The first is the absence of a control group and the second is the absence of long-term followup records. Thus further studies should focus on the long-term results of soft tissue profile changes when the mentalis muscle is precisely reattached in its original
position during graft harvesting surgery, with comparison made to a control group. In conclusion, precise reattachment of the mentalis muscle during symphyseal bone harvesting allows the maintenance of the pre-surgical LIE. Although the thickness of the soft tissue in the symphysis area increases, this increase does not affect the profile and overall aesthetics. Funding
This research was carried out without funding. Competing interests
No conflict of interest to declare.
Please cite this article in press as: Altiparmak N, et al. Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis, Int J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.ijom.2016.09.006
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Lower lip soft tissue after bone graft harvesting Ethical approval
This study was approved by Baskent University Institutional Review Board (Project No. D-KA15/16).
5.
6.
Patient consent
Patient consents were obtained from every patient prior to surgical operations.
7.
References 1. Schwartz-Arad D, Levin L, Sigal L. Surgical success of intraoral autogenous block onlay bone grafting for alveolar ridge augmentation. Implant Dent 2005;14:131–8. 2. Aalam AA, Nowzari H. Mandibular cortical bone grafts. Part 1: Anatomy, healing process, and influencing factors. Compend Contin Educ Dent 2007;28:206–12. 3. No´ia CF, Rodrı´guez-Chessa JG, OrtegaLopes R, Cabral-Andrade V, Barbeiro RH, Mazzonetto R. Prospective study of soft tissue contour changes following chin bone graft harvesting. Int J Oral Maxillofac Surg 2012;41:176–9. 4. Schwartz-Arad D, Levin L. Symphysis revisited: clinical and histologic evaluation for newly formed bone and reharvesting potential of previously used symphysial donor
8.
9.
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11.
sites for onlay bone grafting. J Periodontol 2009;80:865–9. Ellis III E, Zide MF. Surgical approaches to the facial skeleton. Media, PA: Williams and Wilkins; 1995. Rubens BC, West RA. Ptosis of the chin and lip incompetence: consequences of lost mentalis support. J Oral Maxillofac Surg 1989;47:359–66. Wilson HE. The mentalis muscle: its anatomy and clinical significance. Trans Eur Orthod Soc 1975:141–8. Chaushu G, Blinder D, Taicher S, Chaushu S. The effect of precise reattachment of the mentalis muscle on the soft tissue response to genioplasty. J Oral Maxillofac Surg 2001;59:510–6. Soydan SS, Cubuk S, Pektas ZO, Uckan S. The extent of chin ptosis and lower incisor exposure changes following the osseous genioplasties. J Craniofac Surg 2013;24: e445–58. Misch CM. Comparison of intraoral donor sites for onlay grafting prior to implant placement. Int J Oral Maxillofac Implants 1997;12:767–76. Gapski R, Wang HL, Misch CE. Management of incision design in symphysis graft procedures: a review of the literature. J Oral Implantol 2001;27:134–42.
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12. Borstlap WA, Heidbuchel KL, Freihofer HP, Kuijpers-Jagtman AM. Early secondary bone grafting of alveolar cleft defects: a comparison between chin and rib grafts. J Craniomaxillofac Surg 1990;18:201–5. 13. Mazzonetto R. Reconstruc¸o˜es em implantodontia, protocolos clı´nicos para o sucesso e previsibilidade. Nova Odessa: Editora Napolea˜o; 2008: 124–72. 14. Misch CM, Misch CE, Resnik RR, Ismail YH. Reconstruction of maxillary alveolar defects with mandibular symphysis grafts for dental implants: a preliminary procedural report. Int J Oral Maxillofac Implants 1992;7:360–6.
Address: Berat Serdar Akdeniz Department of Orthodontics Faculty of Dentistry Baskent University 11 Sok. Bahcelievler 06490 Cankaya Ankara Turkey Tel: +90 506 320 2362 fax: +90 312 215 2962 E-mail: [email protected]
Please cite this article in press as: Altiparmak N, et al. Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis, Int J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.ijom.2016.09.006
Int. J. Oral Maxillofac. Surg. 2016; xxx: xxx–xxx http://dx.doi.org/10.1016/j.ijom.2016.09.006, available online at http://www.sciencedirect.com
Clinical Paper Dental Implants
Changes in the lower lip soft tissue after bone graft harvesting from the mandibular § symphysis
N. Altiparmak1, B. S. Akdeniz2, S. S. Akdeniz1, S. Uc¸kan3 1
Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Baskent University, Ankara, Turkey; 2Department of Orthodontics, Faculty of Dentistry, Baskent University, Ankara, Turkey; 3Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Medipol University, Istanbul, Turkey
N. Altiparmak, B. S. Akdeniz, S. S. Akdeniz, S. Uc¸kan: Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis. Int. J. Oral Maxillofac. Surg. 2016; xxx: xxx–xxx. # 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Abstract. Following the surgical release of the mentalis muscle, lip incompetence and/or an increase in lower incisor exposure may be seen due to undesirable attachment of the muscle fibres. The aim of this study was to evaluate the extent of lip ptosis, lower incisor exposure, and other soft tissue changes following bone graft harvesting from the mandibular symphysis when the mentalis muscle is reapproximated precisely to its original position. Seventeen consecutive patients who underwent bone graft harvesting from the mandibular symphysis were included in this study. The mentalis muscle was isolated, identified, marked, and reapproximated precisely during the bone harvesting operation. Digital lateral cephalograms obtained preoperatively and at 6 months postoperative were analyzed and compared by paired samples t-test to determine the horizontal and vertical soft tissue changes in the lower lip and chin. Although the soft tissue thickness at soft tissue point B and at soft tissue pogonion had increased significantly at 6 months after chin bone graft harvesting, there were no significant changes in lower incisor exposure or other positional alterations of the lower lip (P < 0.05). Precise reattachment of the mentalis muscle in its original position helps to avoid significant vertical positional changes in the lower lip. Increases in soft tissue thickness can be observed following bone graft harvesting from the mandibular symphysis.
§ This study was accepted as an oral abstract at the 22nd International Conference on Oral and Maxillofacial Surgery, held in Melbourne, Australia, 27–31 October 2015.
0901-5027/000001+05
Alveolar ridge augmentation is a routine procedure performed by clinicians so that implants of the desired width and length can be inserted.1 The autogenous bone grafts for alveolar ridge augmentation are commonly harvested from intraoral
Keywords: lower incisor exposure; chin ptosis; lower lip ptosis; bone graft harvesting. Accepted for publication 8 September 2016
donor sites such as the mandibular ramus and symphysis. Bone graft harvesting from the mandibular symphysis has been reported to be a reliable procedure that offers easy access and an adequate bone tissue volume for grafting.2 However,
# 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Altiparmak N, et al. Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis, Int J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.ijom.2016.09.006
YIJOM-3504; No of Pages 5
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Altiparmak et al.
previous studies on this subject have reported certain soft tissue changes due to the release of the mentalis muscle during the graft harvesting procedure.3,4 The mentalis muscle is the only muscle that is exposed during the surgical approach for symphysis bone graft harvesting.5,6 It is the sole elevator of the lower lip and chin.5 Although there are no fibres that pass into the lower lip, the mentalis muscle also provides major vertical support to the lower lip.5–8 The surgical approach to the osteotomy site when harvesting a bone graft from the symphysis necessitates degloving most of the chin and detachment of the mentalis muscle. If the mentalis muscle is either not functioning or not precisely repositioned after surgery, the result may be extremely unaesthetic because of possible chin ptosis and lip incompetence. Careful reapproximation of the mentalis muscle during flap closure is recommended to avoid these complications.8 Most previous studies on the mandibular symphysis bone graft harvesting procedure have focused on the bone graft itself rather than the neighbouring soft tissues. Lip and chin contour alterations following mandibular symphysis bone grafts have been evaluated previously, with several changes in the vertical plane reported. It has been suggested that further studies are needed to assess the alterations in the soft tissues, such as the lip and chin, after the bone graft block has been harvested from the donor area.3 However information is still missing on the soft tissue changes following a mandibular symphysis bone graft harvesting procedure that enables precise repositioning of the mentalis muscle during closure of the surgical flap. The aim of this study was to compare vertical and sagittal profile changes in the lower lip and chin following mandibular symphysis bone graft harvesting with precise reattachment of the mentalis muscle during closure of the mucoperiosteal flap.
Patients who had undergone previous operations for bone harvesting from the same field, Bone-related systemic diseases such as osteoporosis, which could alter bone remodelling, Patients who received orthodontic treatment during the study, Patients whose central incisors and/or first molars were missing, Patients who received restorations on their first molars or incisors during the study.
device (VarioSurg 50/60 Hz; NSK, Tochigi, Japan). Corticocancellous bone grafts were harvested by straight or inclined osteotomies. No grafts or biomaterials were used to fill the bony defects at the donor sites. The soft tissue closure was completed in two stages. First the mentalis muscle layer was closed by initial marking material with two horizontal mattress sutures, and then the mucosa layer was sutured with 3-0 Vicryl suture material with a simple suturing technique. Measurement methods
Surgical methods
All surgical procedures were performed under local anaesthesia by the same oral and maxillofacial surgeon. Local anaesthetic (4 ml 2% lidocaine with 1:200,000 epinephrine) was administered along the mucosal incision line and mental foramen point for bleeding and pain control. A superficial incision was made through the lower labial mucosa with a scalpel, leaving at least 5 mm of non-keratinized mucosa superiorly between the bilateral lower cuspids. Subsequently, a sub-mucosal incision was made to expose the mentalis muscle. Following the mentalis muscle dissection, the lower and upper ends of the muscle were marked with 3-0 resorbable suture material to suture the muscle in its original position, in accordance with the technique described by Chaushu et al.8 (Fig. 1). Periosteal incision and mucoperiosteal dissection were performed with the marker sutures left on both edges of the muscle fibres. The bilateral mental nerves were identified and protected during the creation of the mucoperiosteal flap. Periosteal attachment of the mental protuberance was preserved in all patients. The osteotomy was performed at least 5 mm below the root apices and 5 mm away from the mental foramen with a piezoelectric surgical
Digital lateral cephalograms were obtained preoperatively and at 6 months postoperative using standardized techniques and equipment. Pre- and postoperative cephalometric tracings and measurements of vertical and sagittal parameters were performed, as shown in the study of No´ia et al.3 Adobe Photoshop Version 13.0 software (Adobe Systems Inc., San Jose, CA, USA) was used for the cephalometric measurements. The vertical parameters measured were lower incisor exposure (LIE), vertical position of the anterior point of the lower lip (VLi), vertical point of the soft tissue point B (VB0 ), vertical point of the soft tissue pogonion (VPg0 ), and lower lip length (LLi) (Fig. 2a). The sagittal parameters measured were lower lip thickness (LLT), soft tissue thickness at soft tissue point B (SB0 ), soft tissue thickness at pogonion (SPg0 ), and the mento-labial angle (MLA) (Fig. 2b). Statistical analysis
The statistical analysis was performed using IBM SPSS Statistics version 21.0 software (IBM Corp., Armonk, NY, USA). A Shapiro–Wilk test of normality verified the normal distribution of the data. Pre- and postoperative measurements were compared using the paired samples t-test with the significance level of P < 0.05.
Materials and methods
Seventeen consecutive adult patients who underwent a mandibular symphysis bone graft harvesting procedure were included in this study. Thirteen were female and four were male, and their mean age was 42.5 9.7 years. All were American Society of Anesthesiologists (ASA) category I. All procedures were performed between January and June 2014. Exclusion criteria were as follows:
Fig. 1. (a) Blunt dissection of the bilateral mentalis muscles. (b) The origin and insertion edges of the mentalis muscle marked with 3-0 resorbable suture material before incision of the muscle fibres.
Please cite this article in press as: Altiparmak N, et al. Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis, Int J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.ijom.2016.09.006
YIJOM-3504; No of Pages 5
Lower lip soft tissue after bone graft harvesting
Fig. 2. (a) The vertical parameters evaluated: lower incisor exposure (LIE), vertical position of the anterior point of the lower lip (VLi), vertical point of the soft tissue point B (VB0 ), vertical position of the soft tissue pogonion (VPg0 ), and lower lip length (LLi). (b) The sagittal parameters evaluated: lower lip thickness (LLT), soft tissue thickness at soft tissue point B (SB0 ), soft tissue thickness at pogonion (SPg0 ), and mento-labial angle (MLA).
Results
The mean changes and statistical differences in parameters measured pre- and postoperatively are shown in Table 1. Although minor increases in LIE (0.9 mm), VLi (0.5 mm), and VB0 (0.7 mm), and minor decreases in VPg0 (0.3 mm) and LLi (0.3 mm) were observed, analysis of the collected data showed that there were no statistically significant changes in any of the vertical parameters. The changes in LIE values are shown in a graph in Fig. 3. While there were statistically significant increases in soft tissue thickness at soft tissue point B and soft tissue pogonion (0.9 and 1.7 mm, respectively), no other sagittal measurement changed significantly (P < 0.05). Bone defects at the osteotomy sites were still distinctly visible in some of the 6-month follow-up cephalograms (Fig. 4). Discussion
Precise reattachment of the mentalis muscle led to minimal changes in LIE and the soft tissue profile.
The mentalis muscles are unique because no other muscles of the chin are incised during stripping of the chin, and once they are incised, their original position is re-established once the periosteum has regained its place.5 A few previous studies have shown that the releasing of the mentalis muscle during symphysis osteotomy increases LIE, which might cause an unaesthetic surgical outcome and might also lead to the patient looking older due to a sagging appearance.3,8,9 The mentalis muscle buttresses the soft tissue of the chin directly and the lower lip indirectly. The fibres of the mentalis muscle pass from their origin inferiorly into the skin of the chin at the level of the soft tissue prominence. The most superior fibres are the shortest and pass almost horizontally into the skin, while the lower fibres are the longest and pass vertically. The origin of the mentalis muscle determines the labial sulcus depth. It is recommended by various researchers that the mentalis muscle is precisely sutured in its original place in order to prevent ptosis resulting from poor positioning or elongation of the muscle.10,11 Two possible reasons are given by Chaushu et al. for ptosis
Table 1. Pre- and postoperative mean values and their statistical comparison. Variable
Preoperative
Postoperative
P-value
LIE VLi VB0 VPg0 LLi LLT SB0 SPg0 MLA
2.24 8.79 20.16 32.09 45.59 16.17 11.34 12.92 127.64
3.19 9.22 20.88 31.64 45.24 15.83 12.23 14.61 128.17
0.10 0.54 0.12 0.65 0.54 0.62 0.034a 0.025a 0.87
LIE, lower incisor exposure; VLi, vertical position of the anterior point of the lower lip; VB0 , vertical point of soft tissue point B; VPg0 , vertical point of soft tissue pogonion; LLi, lower lip length; LLT, lower lip thickness; SB0 , soft tissue thickness at soft tissue point B; SPg0 , soft tissue thickness at pogonion; MLA, mento-labial angle. a Statistically significant difference (P < 0.05).
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related to detachment of the mentalis muscle.8 The first is reattachment of the muscle inferiorly and the second is failing to reattach the muscle in its exact original position.8 Chaushu et al. evaluated the vertical and horizontal alterations in the labium and chin region related to ptosis of the mentalis muscle in 30 patients who underwent an osseous genioplasty.8 In the control group, the mentalis muscle was not marked and the muscle was repositioned via conventional suturing method, while in the experimental group the upper and lower parts of the mentalis muscle were marked and it was placed precisely into its original position during flap closure.8 The researchers emphasized the need for exact determination, proper isolation, and marking of the muscle during mucosal flap elevation in order to reposition it in its original place. They reported that the alterations in profile of the soft tissue were not significant when the mentalis muscle was reattached in its original place.8 No´ia et al. performed a prospective study on patients who underwent mandibular symphysis bone graft harvesting and evaluated the soft tissue alterations in the lower lip and chin.3 They reported that LIE increased 1.7 mm and that the vertical position of the vermilion increased 1.3 mm, which were both statistically significant increases and different from the changes seen in the present study. The most likely reason for this difference is that they did not mark the mentalis muscle during the mucosal flap releasing, and the increase in the appearance of the lower incisors was a result of ptosis of the labium and ptosis of the mentalis muscle. The increase in LIE is an undesired aesthetic result. Therefore, vertical positional alterations of the lower lip can have a serious negative effect on facial aesthetics. The results of the study of No´ia et al. are consistent with those obtained for the control group in the study by Chaushu et al.8 Both studies concluded that the postoperative soft tissue contour alterations at this site resulted from a failure to suture the detached mentalis muscle in its exact original position, rather than to the bone graft harvest. In order to prevent this, both researchers draw attention to the proper isolation, remarking, and suturing of the mentalis muscle in its original position.3,8 Three types of intraoral incision are commonly used for graft harvesting from the mandibular symphysis: sulcular, marginal, and alveolar.11–14 The alveolar mucosal incision was used in the present study to avoid introducing errors caused
Please cite this article in press as: Altiparmak N, et al. Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis, Int J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.ijom.2016.09.006
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Altiparmak et al.
Fig. 3. Preoperative and postoperative values of lower incisor exposure (LIE).
Fig. 4. Lateral cephalometric radiographs of a patient, used in the study: (a) preoperative, and (b) 6 months postoperative. Note the remaining bone defect caused by the graft harvesting operation marked with an arrow. (c) Best-fit superimposition of the pre- and postoperative lateral cephalometric tracings showing the increase in soft tissue thickness at soft tissue point B and pogonion.
by variations in methods. Following the mucosal incision, the mentalis muscle was exposed and the upper and lower edges of the mentalis muscle were marked before the muscle incision, as recommended by Chaushu et al.8 Thus the muscle fibres were sutured to their original position after graft harvesting. No significant alteration in labium profile was observed in the vertical plane in this study, while the soft tissue thickness at soft tissue point B and pogonion was increased in the sagittal plane. Similarly, No´ia et al. reported that the soft tissue thickness increased approximately 2 mm at soft tissue supramentale and pogonion.3 The soft tissue thickness increase at 6 months postoperative was possibly a result
of tissue enlargement into the donor graft cavity during the bone healing period; it did not have a significant effect on the aesthetics of the lower third of the face. Although there was no statistically significant change in LIE in the current study, a mean increase of 0.9 mm in LIE could be seen as an important clinical change. Future studies should focus on further decreasing the amount of contraction of the muscle and LIE. This study has two limitations. The first is the absence of a control group and the second is the absence of long-term followup records. Thus further studies should focus on the long-term results of soft tissue profile changes when the mentalis muscle is precisely reattached in its original
position during graft harvesting surgery, with comparison made to a control group. In conclusion, precise reattachment of the mentalis muscle during symphyseal bone harvesting allows the maintenance of the pre-surgical LIE. Although the thickness of the soft tissue in the symphysis area increases, this increase does not affect the profile and overall aesthetics. Funding
This research was carried out without funding. Competing interests
No conflict of interest to declare.
Please cite this article in press as: Altiparmak N, et al. Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis, Int J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.ijom.2016.09.006
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Lower lip soft tissue after bone graft harvesting Ethical approval
This study was approved by Baskent University Institutional Review Board (Project No. D-KA15/16).
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Patient consent
Patient consents were obtained from every patient prior to surgical operations.
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12. Borstlap WA, Heidbuchel KL, Freihofer HP, Kuijpers-Jagtman AM. Early secondary bone grafting of alveolar cleft defects: a comparison between chin and rib grafts. J Craniomaxillofac Surg 1990;18:201–5. 13. Mazzonetto R. Reconstruc¸o˜es em implantodontia, protocolos clı´nicos para o sucesso e previsibilidade. Nova Odessa: Editora Napolea˜o; 2008: 124–72. 14. Misch CM, Misch CE, Resnik RR, Ismail YH. Reconstruction of maxillary alveolar defects with mandibular symphysis grafts for dental implants: a preliminary procedural report. Int J Oral Maxillofac Implants 1992;7:360–6.
Address: Berat Serdar Akdeniz Department of Orthodontics Faculty of Dentistry Baskent University 11 Sok. Bahcelievler 06490 Cankaya Ankara Turkey Tel: +90 506 320 2362 fax: +90 312 215 2962 E-mail: [email protected]
Please cite this article in press as: Altiparmak N, et al. Changes in the lower lip soft tissue after bone graft harvesting from the mandibular symphysis, Int J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.ijom.2016.09.006