Three-dimensional soft tissue change after paranasal augmentation with porous polyethylene

The aim of this study was to investigate the effect of porous polyethylene (PPE) in paranasal augmentation on midfacial soft tissue architecture. This retrospective study recruited patients with midface retrusion and mandibular prognathism. Twenty adult patients who had undergone bilateral PPE augmentation (ready-made type, thickness 4.5 mm, Medpor) to the piriform aperture and simultaneous mandibular setback surgery were included in this study. The soft tissue morphology and thickness of the midface were evaluated using three-dimensional reformatted images from cone beam computed tomography done before and 6 months after surgery. The soft tissue outline of the midface was augmented 1–4 mm. The average increase in soft tissue outline near the peri-alar region was 3.1–3.4 mm, which comprised 68–74% of the PPE thickness (P < 0.01). The nasolabial angle and columellar inclination were increased significantly (2.2° and 1.4°, respectively; both P < 0.05), whereas the nasal tip angle, nasal tip protrusion, columellar length, and bilateral nostril axis angle did not change. The alar base became wider on average by 2.2 mm (P < 0.01). The results showed that paranasal augmentation with PPE significantly increased the overlying soft tissue outline without influencing the nasal projection and could enhance paranasal aesthetics with minimal morbidity.     

Vertical chin augmentation with interpositional porous polyethylene implants: a histologic study in monkeys

The objective of this paper was to evaluate histologically the tissue reaction in the chin after a vertical augmentation using interpositional porous polyethylene (PPE) implants in monkeys. Six monkeys (Cebus apella) underwent an anterior horizontal mandibular osteotomy with implantation of an interpositional PPE implant to increase the vertical height. The animals were sacrificed 5 months postoperatively. Histologic preparations were stained with hematoxylin and eosin. The perimeter of the interface between the implant and the bone, the implant and the trabecular space, and the implant and the fibrous capsule were quantified using the NIH Image Analysis System (Image 1.60/PPC). In addition, the Tukey test was done. The study demonstrated that bone growth takes place within the pores of the implant; a fibrous capsule exists in some animals, where the implant has contact with the periosteum and mentalis muscle with few chronic inflammatory cells; and the 3 different tissues responded in statistically different manners. Perimeter analysis revealed 68.9% implant-bone contact, 22.9% implant-fibrous tissue contact, and 8.2% implant-trabecular space contact.     

The stability following advancement genioplasty with biodegradable screw fixation

The purpose of this study was to compare postoperative stability using biodegradable screws with that of metal plates for fixation of advancement genioplasty. We studied patients who had advancement genioplasty alone or at the same time as other orthognathic surgery including mandibular setback. We assessed the lateral cephalographs at different time points (preoperatively, and 7 days, 3 months, 6 months, and 12 months postoperatively). A total of 54 patients were enrolled and 27 patients were assigned to each group. The position of pogonion was stable 12 months postoperatively, and the amount of skeletal advancement was reflected in soft tissue close to 100%. There were no clinical differences between biodegradable screws and conventional metal plates used for fixation. Biodegradable fixation for advancement genioplasty is a good option for patients who would require a second operation for removal of the plates.     

Advancement genioplasty in Class I patients: predictability and stability of facial profile changes

This retrospective study evaluated the skeletal and soft tissue facial profile changes as well as the predictability and the short-term stability of the soft-tissue response to advancement genioplasty in Class I dental arch relationship patients. The study included 14 adult patients who presented a Class I dental arch but a Class II skeletal arch relationship and underwent advancement genioplasty exclusively. Lateral cephalograms taken immediately preoperatively (T1), immediately postoperatively (T2) and 1 year postoperatively (T3) were analysed. The hard tissue pogonion was sagittally advanced by an average of 7.9 mm (p < 0.001) (T1-T2). The soft tissue chin followed the sagittal skeletal chin movement and exceeded chin advancement due to the initial soft tissue swelling. In the vertical dimension, the skeletal chin moved 3.0 mm (p < 0.01) upwards whilst the soft tissue chin moved only 2.1 mm upwards (p < 0.01). All profile convexity angles increased significantly (p < 0.001), implying that the profile was straightened by the advancement of the chin. In the short term, advancement genioplasty was a predictable and stable procedure for chin correction. A ratio of 1:1 may be used to predict the sagittal soft tissue to bony movements for the period from before to 1 year after surgery.     

The use of patient-specific implants in genioplasty and its clinical accuracy: a preliminary study

The purpose of this study was to assess the accuracy and clinical validation of patient-specific implants (PSI) in genioplasty. Fifteen patients with chin deformities were enrolled. Virtual planning was performed with the computer-aided surgical simulation method. The three-dimensional-printed titanium cutting guide and patient-specific plate were designed to guide the osteotomy and allow repositioning and fixation of the chin. The outcome was evaluated by comparing the plan with actual outcomes. All operations were successfully completed with PSIs. There was no difficulty in using patient-specific plates. The largest root-mean-square difference of the chin position was 0.69 mm in mediolateral translation and 2.01° in the yaw orientation. The results of the study indicated that the PSI technique was an accurate method of transferring the virtual plan to the operation field with great efficiency in genioplasty. A significant advantage of the PSI technique is that the patient-specific plate could simultaneously complete the repositioning and fixation of the chin. Intraoperative measurements and reposition guides were no longer required. Operative procedures were greatly simplified.     

Repair of fractures of the orbital floor with porous polyethylene implants

Our main aim was to evaluate the long-term results after reconstruction of the orbital floor with porous polyethylene implants. Twenty-six patients with fractures of the orbital floor were included in the study. The main cause of fractures was road crashes. They also complained of enophthalmos (n=19), diplopia (n=21), limited extrinsic ocular motility (n=17), impairment of the infraorbital nerve (n=18), and hypoglobus (n=9). All the fractures were reconstructed with thin and ultra-thin porous polyethylene sheets. No implants extruded and there were no signs of inflammatory reaction against the porous polyethylene. The symptoms were treated in 14 patients with enophthalmos, 18 with diplopia, 16 with limited extrinsic ocular motility, 14 with impairment of the infraorbital nerve and 8 with hypoglobus. Postoperative infections in four patients were treated with systemic antibiotics. Persistent ectropion was present in two patients. Porous polyethylene sheets are reliable, safe and effective implants and may be used for reconstruction of the orbital floor fracture with no donor site morbidity or need to fix implant.     

高位颏前徙术加悬雍垂腭咽成形术治疗阻塞性睡眠呼吸暂停综合征

目的观察高位颏前自徙术加悬雍垂腭咽成形术治疗阻塞性睡眠呼吸暂停综合征的效果。方法选择26例阻塞性睡眠呼吸暂停综合征病人,采用高位颏前徙术加悬雍垂腭咽成形术来治疗,用临床观察、X线头影测量、多导睡眠仪监测等方法进行评价其疗效。结果治疗后全部患者临床症状消失或减轻,面容改善,呼吸紊乱指数减低,最低血氧饱和度增加。结论本方法治疗阻塞性睡眠呼吸暂停综合征简单方便,疗效可靠。     

Aesthetic outcomes and morphological changes in chin parameters after mandibular distraction and subsequent advancement genioplasty in patients with mandibular micrognathia

Despite the wide uses of mandibular distraction osteogenesis (MDO), no study appears to have evaluated the use of MDO and subsequent advancement genioplasty. This study addressed lower facial third aesthetics in a consecutive series of subjects with micrognathia who underwent MDO and subsequent advancement genioplasty. Standard cephalometric measurements were performed pre-MDO, at the end of consolidation, and at 1 week, 6 months, and 12 months after genioplasty. At the end of follow-up, questionnaires were given to measure patient satisfaction. Forty patients were included, 33 of whom underwent genioplasty. The mean patient age was 22.35 ± 1.12 years. Pre-genioplasty cephalometric measurements showed that all patients had a deficient chin position and projection; they were dissatisfied with their facial aesthetics. Post-genioplasty cephalometric measurements showed that the hard and soft tissue pogonion had moved significantly: 8.4 ± 2.3 mm and 11.0 ± 2.11 mm, respectively. According to the questionnaire, the patients were satisfied with the final results. The MDO reduced the amount of chin advancement and minimized relapses; the soft tissue response of the lower facial third was more sensitive to genioplasty than isolated MDO. MDO and genioplasty lead to a modest horizontal chin movement that achieves the preferred pogonion position and projection.     

Vertical alveolar ridge augmentation by means of a titanium mesh and autogenous bone grafts

The aim of this study is to evaluate a surgical protocol for vertical ridge augmentation in the maxilla and mandible using autogenous onlay bone graft associated with a titanium mesh. A group of 18 partially edentulous patients, presenting the need for vertical bone augmentation of at least 4 mm, were treated before implant placement. During the first surgery, an autogenous bone graft was harvested from either the mandibular ramus or the mental symphysis and secured by means of titanium screws. Particulate bone was added and a titanium micro-mesh was used to stabilize and protect the graft. After a mean interval of 4.6 months, meshes and screws were removed and 37 endosseous implants were successfully placed. The desired bone gain was reached in all patients. Mean vertical bone augmentation obtained was 4.8 mm (range 4-7 mm). No major complications were recorded at recipient or donor sites. Abutment connection was carried out 2-3 months after implant placement. No implant was lost. Clinical parameters and probing depth, after prosthetic reconstruction, demonstrated the presence of a healthy peri-implant mucosa. The preliminary results suggest that, by using the presented technique, patients can be successfully rehabilitated by means of implant-supported prosthesis 6-7 months after the first surgery, even in case of severely atrophied maxilla.     

Vertical augmentation with interpositional blocks of anorganic bovine bone vs. 7‐mm‐long implants in posterior mandibles: 1‐year results of a randomized clinical trial

Objectives: To evaluate whether 7‐mm‐long implants could be an alternative to longer implants placed in vertically augmented posterior mandibles. Materials and methods: Sixty patients with posterior mandibular edentulism with 7–8 mm bone height above the mandibular canal were randomized to either vertical augmentation with anorganic bovine bone blocks and delayed 5‐month placement of ≥10 mm implants or to receive 7‐mm‐long implants. Four months after implant placement, provisional prostheses were delivered, replaced after 4 months, by definitive prostheses. The outcome measures were prosthesis and implant failures, any complications and peri‐implant marginal bone levels. All patients were followed to 1 year after loading. Results: One patient dropped out from the short implant group. In two augmented mandibles, there was not sufficient bone to place 10‐mm‐long implants possibly because the blocks had broken apart during insertion. One prosthesis could not be placed when planned in the 7 mm group vs. three prostheses in the augmented group, because of early failure of one implant in each patient. Four complications (wound dehiscence) occurred during graft healing in the augmented group vs. none in the 7 mm group. No complications occurred after implant placement. These differences were not statistically significant. One year after loading, patients of both groups lost an average of 1 mm of peri‐implant bone. There no statistically significant differences in bone loss between groups. Conclusions: When residual bone height over the mandibular canal is between 7 and 8 mm, 7 mm short implants might be a preferable choice than vertical augmentation, reducing the chair time, expenses and morbidity. These 1‐year preliminary results need to be confirmed by follow‐up of at least 5 years. To cite this article:
Felice P, Pellegrino G, Checchi L, Pistilli R, Esposito M. Vertical augmentation with interpositional blocks of anorganic bovine bone vs. 7‐mm‐long implants in posterior mandibles: 1‐year results of a randomized clinical trial.
Clin. Oral Impl. Res 21 , 2010; 1394–1403.
doi: 10.1111/j.1600‐0501.2010.01966.x     

Reduction genioplasty enhances quality of life in female patients with prognathism and maxillary hypoplasia undergoing bimaxillary osteotomy

The structure of the chin determines facial attractiveness and is directly linked to quality of life (QoL). In patients with prognathism and maxillary hypoplasia, bimaxillary osteotomy (BIMAX) with mandibular setback does not always lead to a more slender chin or improved aesthetics. The aim of the present study was to evaluate whether QoL differed between females undergoing BIMAX alone (group I; n = 30) and those undergoing BIMAX combined with reduction genioplasty (group II; n = 30). Presurgical and postsurgical evaluations included cephalography, photogrammetry, and the Oral Health Impact Profile with one additional domain (aesthetics). Setback of the hard tissue pogonion was significantly greater (P = 0.006) in group II (7.1 mm) than in group I (2.7 mm). Only in group II were soft tissue pogonion changes highly significant (P < 0.001), amounting to a mean of 5 mm. In both groups, the QoL domains ‘social disability’, ‘psychological discomfort’, and ‘dissatisfied with aesthetics’ changed significantly towards lower impact scores. Changes in the latter two domains were significantly greater in group II patients than in group I patients (P = 0.021; P < 0.001) and were correlated with changes in the soft tissue pogonion in the horizontal (P = 0.024; P = 0.022) and vertical directions (P = 0.037; P = 0.042). Genioplasty addresses both psychological and aesthetic concerns, and therefore significantly enhances postsurgical QoL.     

Genioglossus muscle advancement and simultaneous sliding genioplasty in the management of sleep apnoea

Genioglossus muscle advancement (GMA) was reported in 1993 as an option for the surgical treatment of obstructive sleep apnoea syndrome (OSAS), in the context of phase I of the Stanford University (Powell–Riley) protocol. The rationale for this technique is the placement of tension on the base of the tongue, thus preventing the tongue from falling back into the posterior airway space. However, in retrognathic patients undergoing phase I of the Stanford University protocol, an additional genioplasty will provide a better aesthetic outcome. Furthermore, genioplasty is one of the most common and versatile techniques used for the correction of dentofacial deformities. The aim of this article is to describe a technique that allows a combination of genioglossus muscle advancement (GMA) and a simultaneous sliding genioplasty. This technique can be used in patients undergoing phase I surgery, or in patients in whom a sliding genioplasty could be complemented by GMA. The advantage of this procedure is the aesthetic enhancement obtained in GMA patients. The indications, contraindications, complications, and outcomes of surgery in the first 15 patients treated with this technique are reported herein.     

Vertical bone augmentation with fluvastatin in an injectable delivery system: a rat study

Objectives: HMG-CoA reductase inhibitors (statins) are widely used for hyperlipidemia. Previous studies demonstrate that statins stimulate bone morphogenetic protein-2 (BMP-2) expression and lead to bone formation. The aim of this study was to evaluate whether percutaneously injected statin with a novel statin delivery system achieved vertical bone augmentation.
Material and methods: As experimental groups, atelocollagen-α-tricalcium phosphate (αTCP) composites containing 3.3 mg (low dose) or 6.7 mg (high dose) of fluvastatin were injected (one shot) subcutaneously over the calvarial periosteum of rats. The animals were then sacrificed 1, 2, and 4 weeks after injection. Vertically augmented bone was assessed by histomorphometric procedures, i.e., by measuring new bone thickness (NBT) and bone density (BD).
Results: In control groups, no newly formed bone could be seen over the calvarial bone. In the experimental groups, in contrast, a large amount of newly formed bone could be seen over the preexisting calvarial bone. The newly formed bone was seen to be in direct contact with the preexisting bone. During the entire observation, significant NBT was observed in the experimental groups ( P <0.05). At the final stage of observation (4 weeks), NBT was 66.7% (low-dose group) and 59.7% (high-dose group), while they were from 1% to 16.3% in the control groups. In the experimental groups, BD significantly increased in a time-dependent manner.
Conclusion: Percutaneously applied fluvastatin (one shot) with a composite of αTCP and collagen has great potential to augment the height of the bone.     

颏部畸形及治疗

颏部是面部重要的美学单位,颏部畸形是常见的面部美容手术之一。颏部畸形常见的治疗方法有自体组织移植、异体材料填充和颏部截骨,但对于方法选择尚存争议。本文探讨了各种方法的适应证、操作重点及注意事项,并推荐美容整形外科医生掌握这些技术,来解决更多的颏部畸形。     

Vertical ridge augmentation with guided bone regeneration in association with dental implants: an experimental study in dogs

AIM: To evaluate the effect of using guided bone regeneration (GBR) with a titanium-reinforced e-PTFE membrane in alveolar bone defects with titanium implants. MATERIAL AND METHODS: Following extraction of three mandibular premolars and a molar on both sides of the jaw in three dogs, alveolar bone defects (depth: 5-7 mm) were produced. After 4 months, three implants were inserted into each defect to a depth of approximately 4 mm, so that their coronal portion was protruding about 5 mm. Four sides in the dogs were assigned to a test group and the remaining two sides to a control group. The 12 implants in the test group were covered with a reinforced e-PTFE membrane. The space under the membrane was filled with peripheral venous blood from the animal, and the flaps were sutured over the membrane. The six control implants received no membrane before the suturing of the flaps to complete wound closure. The animals were sacrificed after 6 months, and non-decalcified histological specimens of the implants and surrounding tissues were prepared. RESULTS: Histologic and histomorphometric analyses revealed a significantly (Mann-Whitney test; P=0.08) larger amount of bone fill in the test group (mean=57.42%) than in the controls (mean=11.65%), and clinical evaluation of one test site showed that the implants were completely covered with tissue resembling bone. In most of the specimens, bone had grown in height close to, or in direct contact with the membrane. However, the new bone generally was not in direct contact with the implants. Regularly, a zone of dense connective tissue was interposed between the implants and the newly formed bone. CONCLUSION: The formation of even considerable amounts of bone following vertical ridge augmentation with GBR and implants was not accompanied by predictable osseointegration of the implants.     

Hard and soft tissue changes and long-term stability after vertical height reduction genioplasty using biodegradable fixation

The aim of this work was to analyse the stability of vertical height reduction genioplasty using biodegradable material, as well as to determine vertical changes of hard and soft tissues during this procedure.Forty patients underwent vertical height reduction genioplasty using two types of biodegradable fixation (Biosorb FX^® or OSTEOTRANS-MX^®), combined with mandibular setback surgery. We assessed lateral cephalographs over time (pre-operation; immediately post-operation; 3 months, 6 months and 12 months post-operation).We found a mean vertical difference of 0.22 mm (standard deviation (SD) = 0.49 mm) at the menton point immediately post-operation, compared with 12 months post-operation. And there was no statistical significance(P > 0.05). The chin hard tissue remained stable from the immediate post-operation period to 1 year post-operation, and the chin soft tissue remained stable from 3 months to 1 year post-operation. The regression equation describing the replacement of hard tissue with soft tissue change, between pre-operation and 12 months post-operation is y = 0.590x + 0.885 (R² = 0.300, P < 0.001).We confirm that the use of biodegradable fixation is a stable method, in terms of skeletal tissues, and a relatively stable method, in terms of soft tissues. In vertical height reduction genioplasty, soft tissue does not reflect 100% of the vertical tissue reduction in hard tissues. This data may influence establishment of surgical treatment objectives.