CRANIOMAXILLOFACIAL DEFORMITIES/COSMETIC SURGERY

Osteotomy of the Nasal Wall Using a Newly Designed Piezo Scalpel—A Cadaver Study Alireza Ghassemi, MD, DDS, PhD,* Andreas Prescher, MD, PhD,y Mohammad Talebzadeh, DDS,z Frank Holzle,€ MD, DDS, PhD,x and Ali Modabber, MD, DDS, PhDk

Purpose: Achieving the desired outcome in rhinoplasty depends on many factors. Osteotomy and adjustment of the lateral nasal wall are important steps that necessitate careful planning and execution. A cadaver study was performed to evaluate the osteotomy result obtained with a newly designed piezoelectric-based scalpel. Materials and Methods: Twenty lateral osteotomies of the nasal wall were performed in 10 human cadaver noses. The osteotomies were conducted in 6 female and 4 male cadavers (age range, 65 to 83 yr; mean age, 74.8 yr). A specially designed Piezosurgery-based scalpel was used endonasally to perform the lateral osteotomy. Cutting of the bony nasal wall was performed subperiostally along the planned osteotomy route under tactile control. Digital infracturing was accomplished by applying gentle pressure. After completing the osteotomy, the osteotomy line and nasal mucosa were examined endoscopically. The skin cover was removed to examine the lateral bony nasal wall for the shape and amount of bone fragments, the osteotomy path, and mucosa involvement. Results: Using the Piezosurgery-based scalpel required a learning curve, but the handling was easy. It allowed an exact performance of the osteotomy and caused no mucosal tearing. If excessive force was used, the piezo tip stopped working. There was no comminuted fracture pattern and the lateral nasal wall remained in 1 piece. The duration of the osteotomy was 5 to 10 minutes on each side. Conclusion: The piezoelectric-based scalpel is a useful tool, which can be used to perform osteotomy of the nasal wall. In addition, this specifically designed tool tip allows an endonasal approach, is easy to han- dle, and allows effective irrigation of the osteotomy region. Ó 2013 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg -:e1-e6, 2013

A significant yet difficult contributor to operative suc- to make this step predictable, less traumatic, easy to per- cess in rhinoplasty is shaping the underlying nasal form, and controllable.2,4-7 Nevertheless, every tech- bony structures.1,2 Depending on the deformities nique has its advantages and disadvantages, and presented, different osteotomy techniques—lateral, osteotomy can cause soft tissue injury, irregularity of medial, and transverse—can be indicated to achieve the bony lateral wall, a comminuted fracture pattern, the desired esthetic and functional outcome.3 Two dif- and, as sequels, prolonged postoperative edema and ferent approaches—endonasal and percutaneous— ecchymosis and functional nasal obstruction with an with corresponding instruments have been developed undesired esthetic and functional outcome.2,5-7 Soft

*Assistant Professor, Department of Oral, Maxillofacial, and kSenior Resident, Department of Oral, Maxillofacial, and Plastic Plastic Facial Surgery, University Hospital RWTH-Aachen, Aachen, Facial Surgery, University Hospital RWTH-Aachen, Aachen, Germany. Germany. Address correspondence and reprint requests to Dr Ghassemi: yAssistant Professor, Institute of Anatomy, Medical Faculty of Pauwelsstr 30, 52074 Aachen, Germany; e-mail: aghassemi@ RWTH-Aachen, Aachen, Germany. ukaachen.de zResident, Department of Oral, Maxillofacial, and Plastic Facial Received June 18 2013 Surgery, University Hospital RWTH-Aachen, Aachen, Germany. Accepted July 26 2013 xHead and Chairman, Department of Oral, Maxillofacial, and Ó 2013 American Association of Oral and Maxillofacial Surgeons Plastic Facial Surgery, University Hospital RWTH-Aachen, Aachen, 0278-2391/13/00939-7$36.00/0 Germany. http://dx.doi.org/10.1016/j.joms.2013.07.028

e1 e2 PIEZO SURGERY FOR OSTEOTOMY OF NASAL WALL tissue trauma may contribute to destabilization, addition, irrigation with internal cooling and a flow hemorrhage, and prolonged postoperative ecchymosis of 40 mL/min was used to avoid heating the bone. and edema. The nasal skin is very thin and any nasal The coolant was transferred to the osteotomy area wall irregularity from a comminuted fracture and through a hole at the end of the tool tip (Fig 2). irregular-shaped bony fragments will be apparent.8,9 The mucosa was incised along the lower edge of the Horton et al10,11 introduced piezo surgery in alveolar pyriform aperture for about 3 mm to access the bony bone surgery in 1975, using the piezoelectric ultrasonic lateral wall. A special tool tip was used as a periosteal vibration for gentle cutting of the bone. They reported elevator to create a subperiosteal tunnel around the better bone healing of the bony fragments when using pyriform aperture along the planned osteotomy piezo surgery. Subsequently, additional uses were path, as marked on the skin (Fig 3). The piezo scalpel introduced, such as cutting a bony window in the was inserted into this tunnel and the osteotomy was maxillary sinus wall to perform sinus augmentation or performed along the osteotomy path under digital con- to perform orthognathic surgery.10-16 In 2007, trol. After accomplishing the endonasal cutting of the Robiony et al17 suggested this technique for nasal os- bony lateral nasal wall, 3 independent examiners (ex- teotomy. This device cuts the bone micrometrically us- cluding the surgeons) who were blinded to the tech- ing ultrasonic piezoelectric vibration, and it can be nique inspected the intranasal cavities of all cadavers adjusted by changing the frequency and cutting power. on each side with a 4-mm 30 rigid endoscope (Karl It has proved a useful tool for cutting thin bone with Storz GmbH & Co KG, Tuttlingen; Germany). They precision, causing minimal damage to soft tissue and looked for lacerations of the nasal mucosa. Then, the avoiding osteonecrosis.18 Since then, the technique nasal pyramid was infractured digitally on each ca- has improved rapidly and has extended its indication.12 daver. The soft tissue envelope was removed after in- This anatomic study was undertaken to perform fracturing to evaluate the condition of the osteotomy osteotomy of the nasal wall with a newly designed line and the size, shape, and amount of the bony frag- piezo scalpel. The degree of difficulty of performing ments. Special inspection was performed for contour osteotomy was evaluated using this scalpel through irregularities, bony spur or spicules generated, and an endonasal approach. In addition, the effectiveness greenstick infracture characteristics. This step was fol- of the cooling capacity, the condition of the osteotomy lowed by an intranasal examination to explore the path, the amount and shape of bony fragments, and nasal mucosa. mucosal injuries were examined. Results Materials and Methods Altogether, 20 lateral osteotomies were performed Ten human cadaver heads were used for performing in human cadaver specimens. The osteotomy path lateral osteotomy (age range, 65 to 83 yr; mean age, was marked on the skin (Fig 3). It was easy to cut 74.8 yr; gender distribution, 4 male and 6 female). through the bony wall all the way along the osteotomy One experienced rhinoplasty surgeon, who was famil- line by digitally controlling the piezo inset (Figs 1, 2). iar in applying the Piezosurgery device (Mectron Med- Because of the learning curve, 10 minutes was re- ical Technology, Carasco, Italy), performed the quired for the first nose and 7 minutes was required osteotomies through an endonasal approach. A spe- for the second nose. For the next 8 noses, approxi- cially designed piezo scalpel was used to dissect a tun- mately 5 minutes was required. For continuous cut- nel and to perform the osteotomy (Figs 1, 2). In ting, the scalpel should be moved along the bone

FIGURE 1. Working insert for soft periosteal elevation. The cooling hole (arrow) is in the shaft near the handle. Ghassemi et al. Piezo Surgery for Osteotomy of Nasal Wall. J Oral Maxillofac Surg 2013. GHASSEMI ET AL e3

FIGURE 2. The cutting working tip with the hole close to the tip. The cooling hole (arrow) and the pathway along the shaft, where the irrigation has to flow to reach the tip (2-headed arrow), are depicted. Ghassemi et al. Piezo Surgery for Osteotomy of Nasal Wall. J Oral Maxillofac Surg 2013. surface by applying gentle pressure. This is sufficient surgery, digital infracturing could be performed by ap- to cut partly or completely through the bone, as indi- plying gentle pressure and no forceful manipulation cated. As soon as any extensive force was exerted, was necessary. the piezo stopped working. Near the nasal root, cut- All examiners independently recorded identical ting the bone required more time. At the end of piezo findings from their separate endoscopic examinations

FIGURE 3. Osteotomy course marked on the skin of the cadaver nose. This was used continuously to control the tip of the piezo scal- FIGURE 4. Endoscopic inspection of nasal mucosa after osteot- pel while performing the osteotomy. omy. No injury to the mucosa is observed. Ghassemi et al. Piezo Surgery for Osteotomy of Nasal Wall. J Oral Ghassemi et al. Piezo Surgery for Osteotomy of Nasal Wall. J Oral Maxillofac Surg 2013. Maxillofac Surg 2013. e4 PIEZO SURGERY FOR OSTEOTOMY OF NASAL WALL

a way as to provide esthetically pleasing and reliable re- sults. Lateral osteotomy is associated with an increase in hemorrhage, edema, and ecchymosis. This has been substantiated by other studies and can contribute signif- icantly to postoperative morbidity after rhinoplasty.2,5-9 Perforated lateral osteotomy preserves the support of the periosteum and is supposed to decrease lateral nasal wall collapse and minimize hemorrhages and edema.5-7 However, this method is suspected of causing comminuted fractures with irregular bony fragments, which can cause postoperative esthetic deformity.4 The perforating technique is reliable only in the hands of an experienced surgeon, because it is dif- ficult to direct and may need repeated passes.2,9 Murakami and Larrabee4 found more irregular osteoto- mies and more soft tissue trauma when using the per- cutaneous approach, and they preferred building a subperiosteal tunnel and using an adequate technique to ensure proper stability. In a cadaver study, Kuran et al19 evaluated fracture line and mucosal injuries. They found that a wide osteotome causes significantly more mucosal injuries. The piezo scalpel allows the cutting of a bony win- dow into the maxilla without any laceration of the del- icate mucosa of the maxillary sinus.13 Robiony et al17 FIGURE 5. Osteotomy course after removal of soft tissue cover. A introduced the piezo technique in rhinoplasty and em- very tiny tooth mark along the osteotomy path, caused by the tip of the piezo scalpel, is depicted. The osteotomy course is regular, phasized the advantages of this method. They used an which corresponds exactly to the path marked on the skin. There external approach to insert the piezo scalpel. Although is only 1 bony fragment without any comminuted fracture pattern. soft tissue probably will not be lacerated by slight Ghassemi et al. Piezo Surgery for Osteotomy of Nasal Wall. J Oral touches, continuous irrigation would be difficult using Maxillofac Surg 2013. this approach. Robiony et al reported decreased bleed- ing during surgery, minor edema, and periorbital ec- chymosis immediately after surgery. The Piezosurgery and from the condition of the lateral nasal wall. None device offers effortless handling and requires very little of the cadavers exhibited perforation of the nasal mu- manual pressure.22 Moreover, it is an optimal tech- cosa (Fig 4). The examiners recorded 1 complete nasal nique for selectively cutting mineralized tissue.10 It al- wall on each side, with small irregularities resembling lows the exact placement and control of the tool tip the tooth of the piezo scalpel. There was minimal loss to cut along the desired path using micrometric move- of bone material along the osteotomy line (Fig 5). ment, and the piezo scalpel is armed with a peristaltic pump for irrigation.14,16,22 Although this instrument Discussion was originally developed for augmentation surgery in the dentoalveolar field, there are different working Successful rhinoplasty is the result of controlled tips for currently available indications.11-17,22 changes in the nasal framework and its soft tissue cover. The main purpose of this cadaver study was to Alterations and shaping of the nasal bony structure pres- evaluate the quality of osteotomy when using the Pie- ent an ongoing challenge in esthetic and reconstructive zosurgery device. The newly designed piezo scalpel surgery.1 Numerous lateral osteotomy techniques allowed the osteotomy from an endonasal approach evolved in the previous century, incorporating the use and irrigation of the bone through a hole close to of different instruments from the saw to the chisel to the tip of the scalpel (Fig 2). Lateral osteotomy was the diamond.2-7,19-21 Various modifications of available performed in 10 human cadaver noses (20 lateral techniques have been introduced to rhinoplasty walls) according to the technique described earlier. surgery to increase ease of performance, precision, A 3-mm incision in the mobile mucosa of the pyri- controllability, and reliability, on the one hand, and form aperture and narrow exposure of the osteotomy reproducibility with low morbidity, on the other. site were sufficient to easily access the lateral nasal Despite the many previously described methods, it wall. A short learning curve was necessary to become remains difficult to perform osteotomies in such familiar with the procedure. The exposure of bone GHASSEMI ET AL e5 surface at the osteotomy site was less extensive than incision conjures debate when an internal option with other methods. The line of osteotomy, which exists.2 This specially designed piezo scalpel allows an en- had been marked on the skin along the nasofacial donasal approach and thus avoids any risk of possible crease, could be palpated and followed exactly scar formation. through the skin (Fig 3). The hand piece stopped The optimal technique for osteotomy should be safe, moving if any excessive force was used.22 It should precise, and reproducible, with minimal postoperative just be guided over the bone gently, as in piezo sur- ecchymosis and edema, and deliver a predictable re- gery generally. It does not involve the risk of acciden- sult. The piezo scalpel is easy to handle and does not tal dislocation of the osteotome and the course of cause any mucosa laceration; the osteotomy can be osteotomy can always be followed exactly as performed exactly in the planned osteotomy track planned.22 The sound of the cutting also can help and does not result in any comminuted fractures. It is as acoustic feedback to guide the applied force. a nontraumatic and controllable alternative to known The infracturing of the bony lateral wall can be ac- osteotomy techniques. A learning curve may be neces- complished with gentle pressure. The endoscopic ex- sary, but it is a straightforward method to learn. amination along the osteotomy line showed a bone ridge with spikes, similar to the tip of the scalpel, but no major irregularity or comminuted fracture References (Fig 5). No tear of nasal mucosa was apparent 1. Thomas JR, Griner NR, Remmler DJ: Steps for a safer method of (Fig 4). The average time for incision and preparation osteotomy in rhinoplasty. Laryngoscope 97:746, 1987 was 5 minutes after a learning curve in the first 2 os- 2. Becker DG, McLaughlin RB, Loevner LA, et al: The lateral osteot- teotomies. No residual deformity, such as a bony omy in rhinoplasty: Clinical and radiographic rationale for osteo- tome selection. Plast Reconstr Surg 105:1806, 2000 spur, was observed. The lateral nasal wall was ob- 3. Harshbarger RJ, Sullivan P: The optimal medial osteotomy: A served as a whole bone fragment, with some irregu- study of nasal bone thickness and fracture patterns. Plast Re- larities of the bone edge caused by the tooth of the constr Surg 108:2114, 2001 4. Murakami CS, Larrabee WF: Comparison of osteotomy tech- piezo tool tip. The osteotomy part of the bone niques in the treatment of nasal fractures. Facial Plast Surg 8: showed signs of adequate irrigation and no sign of 209, 1992 heat development. The irrigation flowed through 5. Goldfarb M, Gallups J, Gerwin J: Perforating osteotomies in rhi- noplasty. Arch Otolaryngol Head Neck Surg 119:624, 1993 the shaft of the scalpel to the tip. This had an addi- 6. Rohrich RJ, Janis JE, Adams WP, et al: An update on the lateral tional cooling effect on the surrounding soft tissue nasal osteotomy in rhinoplasty: An anatomic endoscopic com- coverage (Fig 2). In some noses, the osteotomy parison of the external versus the internal approach. Plast Re- constr Surg 111:2461, 2003 path was osteotomized incompletely. Nevertheless, 7. Gryskiewicz JM, Gryskiewicz KM: Nasal osteotomies: A clinical the infracturing could be performed easily. The re- comparison of the perforating methods versus the continuous sulting osteotomy gap was approximately 0.5 mm.22 technique. Plast Reconstr Surg 113:1445, 2004 8. Ford CN, Battaglia DG, Gentry LR: Preservation of periosteal at- Because the use of piezo surgery does not cause any tachment in lateral osteotomy. Ann Plast Surg 13:107, 1984 soft tissue injury, minimal hemorrhage and ecchymosis 9. Erisir F, Tahamiller R: Lateral osteotomies in rhinoplasty: A safer are expected postoperatively, as was shown clinically and less traumatic method. Aesthet Surg J 28:518, 2008 17 10. Horton JE, Tarpley TM, Wood LD: The healing of surgical defects by Robiony et al. The dissection of a narrow subper- in alveolar bone produced with ultrasonic instrumentation, iosteal tunnel, combined with healthy and unlacerated chisel, and rotary burr in the surgical removal of bone. Oral nasal mucosa, will hinder the collapse of the osteotom- Surg Oral Med Oral Pathol 39:536, 1975 11. Horton JE, Tarpley TM, Jacoway JR: Clinical applications of ultra- ized lateral nasal wall and thus decrease postoperative sonic instrumentation in the surgical removal of bone. Oral Surg 9 edema and swelling. A precise and reproducible lateral Oral Med Oral Pathol 51:236, 1981 osteotomy can be performed, which is the requirement 12. Sherman JA, Davies HT: UltracisionÒ: The harmonic scalpel and its possible uses in maxillofacial surgery. Br J Oral Maxillofac for successful rhinoplasty. It can be controlled transcu- Surg 38:530, 2000 taneously to perform the osteotomy in an exact planned 13. Vercelotti T, de Paoli S, Nevins M: The piezoelectric bony course. It makes this step easier to perform and more window osteotomy and sinus membrane elevation: Introduc- tion of a new technique for simplification of the sinus aug- controllable, with a predictable and consistent result. mentation procedure. Int J Periodontics Restorative Dent This promotes faster healing and shortens postopera- 21:561, 2001 tive hospital stay.9 Because the bone thickness does 14. Eggers G, Klein J, Blank J, et al: Piezosurgery: An ultrasound de- vice for cutting bone and its use and limitations in maxillofacial not exceed 3 mm at any point on the osteotomy lines, surgery. Br J Oral Maxillofac Surg 42:451, 2004 19,23 piezo surgery is optimal for this procedure. In 15. Gruber RM, Kramer FJ, Merten HA, et al: Ultrasonic surgery—An addition, there is no need to cut through the entire alternative way in orthognathic surgery of the mandible. A pilot study. Int J Oral Maxillofac Surg 34:590, 2005 thickness of the nasal bone to infracture the nasal wall. 16. Robiony M, Polini F, Costa F, et al: Piezoelectric bone cutting in All kinds of osteotomies, such as transverse, median, multipiece maxillary osteotomies. J Oral Maxillifac Surg 62:759, paramedian, and hump removal, also can be performed 2004 17. Robiony M, Toro C, Costa F, et al: Piezosurgery: A new as required. Although there is limited scarring from the method for osteotomies in rhinoplasty. J Craniofac Surg 18: percutaneous approach, the concept of an ex