Prof. Dr. Özcan Çakmak
Prof. Dr. Özcan Çakmak
Prof. Dr. Ozcan Cakmak is an European Board certified Facial Plastic Surgeon. He worked in academic positions at universities in Ankara, and Istanbul, then passed to full private practice and founded FACEISTANBUL Facial Plastic Surgery Clinic.
His focus on cosmetic surgery of the face allows him to provide his patients with expertise. Dr. Cakmak customizes your surgery with the utmost in care and the most cutting-edge techniques depending on your specific needs. His experience will ensure your results are consistent and natural-looking.
As an expert in aging face surgery and rhinoplasty, he regularly gives lectures in national and international congresses. He is currently Rejuvenation Focus Group Chair, and Fellowship Program Director of European Academy of Facial Plastic Surgery.
Education and Work Experiences
- FACEISTANBUL (Private practice) (2014- )
- Acıbadem Kadıkoy Hospital, Istanbul, Turkey (2009- 2014 ).
- European Academy of Facial Plastic Surgery, Chair, Rejuvenation Focus Group (2013- )
- European Academy of Facial Plastic Surgery, Member, Board of Directors (2013-2015)
- Examiner, European Board of Facial Plastic Reconstructive Surgery, London, 2013.
- Oral Maxillo-Facial Surgeon title (2013)
- Professor Degree: 2010, Acıbadem University, Istanbul, Turkey.
- European Academy of Facial Plastic Surgery, Clinical Fellowship Director (2011- )
- Board Certification of European Academy of Facial Plastic Surgery Society (International Federation of Facial Plastic Surgery
- Society (IFFPSS) Unified International Certification program), Washington DC, USA, June 2008.
- Baskent University Hospital, Otorhinolaryngology Department, Associate Professor, Ankara, Turkey (1999- 2009).
- Quatela Facial Plastic Surgery Center, visiting clinician, 2 June- 12 July 2007.
- Perkins – Vannata Clinic (Facial Plastic Surgery), visiting clinician, 15 – 25 December 2004.
- Associate Professor Degree: Baskent University, Ankara, Turkey, 2003.
- Oregon Health Sciences University, Otorhinolaryngology Department, Division of Facial
- Plastic Surgery, Portland, Oregon, visiting clinician, August – September 2001.
- Larrabee Center (Facial Plastic Surgery), Seattle, Washington, visiting clinician, August – September 2000.
- Assistant Professor Degree, Baskent University, Ankara, Turkey, May 2000.
- Mayo Clinic, Department of Otorhinolaryngology, Rhinology and Facial Plastic Surgery Divisions, Rochester, Minnesota, visiting clinician, September 1998-December 1998.
- Otorhinolaryngology Residency, Hacettepe University Medical School, Ankara, Turkey, 1992 – 1997.
- Medical School, Hacettepe University Medical School, Ankara, Turkey, 1985- 1992.
- Scientific Society Memberships
- European Academy of Facial Plastic Reconstructive Surgery Society, National Delegate of Turkey, Chair of Rejuvenation Focus Group.
- American Academy of Facial Plastic Reconstructive Surgery Society, International Member
- Turkish Facial Plastic Surgery Society, Founder Member, General Secretary (2008 -2012)
- Turkish Medical Association, Private Practice Branch General Secretary (2014 -2016)
International Invited Speaker
1. AAFPRS Advances in Rhinoplasty, Orlando, Florida, US, April 4-7, 2019.
Saddle nose deformity: etiology, physiology, algorithm for repair, Alar collapse: prevention and correction, dorsal contour irregularity management, acoustic rhinometry & CT for airway evaluation.
2. First International Congress of Facial Plastic Surgery of Isfahan, Iran, October 3-5, 2018.
Deep-composite facelift, Blepharoplasty: Anatomy and techniques, Crushed cartilage grafts to conceal dorsal irregularities
3. 41th Annual Meeting of European Academy of Facial Plastic Surgery Society, Regensburg, Germany, September 12-15, 2018.
International Scientific Committee Member, Deep/composite facelift, why and how, Blepharoplasty: how to avoid skeletonized eyes.
4. 3rd International Rhinoplasty and Facial Plastic Surgery Course, India, Hydarabad, India, August 31-September 2, 2018.
Deep/Composite Rhytidectomy, anatomy for safe facelift/midfacelift, Blepharoplasty techniques and strategies. Live surgery: Composite Facelift performed by Ozcan Cakmak.
5. FACEISTANBUL 2018, Istanbul, Turkey, May 29-30 2018.
(Chair of the Meeting)
Deep-composite flap facelift, Blepharoplasty: Anatomy-techniques, Chemical peeling – dermabrasion, radiofrequency for skin rejuvenation (moderator)
Live Surgery (performed by Ozcan Cakmak): Modified composite plane facelift, upper-lower blepharoplasty, endoscopical brow lift, Upper lip lift, Fat injection, TCA peeling to the face
6. London Fact 2018, London, UK, 5-6 March, 2018.
Invited International faculty for the aging face surgery cadaver dissection course.
7. 40th Annual Meeting of European Academy of Facial Plastic Surgery Society, Lisbon, Portugal, 27-30 September, 2017.
Facelift: How to get long term stable results (panelist), Aging face surgery panel (moderator), Midfacelift (panelist), Composite facelift (video panel), History of Facial Plastic Surgery in Turkey.
8. Face 2017 Madrid, Madrid, Spain, May 31-June 3, 2017. Blepharoplasty: step by step, A case that changed my mind, The magic in the eyes (panelist), When the tip is even more (panelist).
9. RinoArrabiada 2016, Porto, Portugal, November, 11-13, 2016.
Diagnosis and management of tip deformities, Clinical case: how would you do it?, Saddle nose reconstruction algorithm, Crushed cartilage grafts to camouflage contour irregularities.
10. Annual Fall Meeting of American Academy of Facial Plastic Reconstructive Surgery, Nashville, TN, US, 6-8 October, 2016.
Crushed cartilage grafts for saddle nose reconstruction (panelist)
11. 39th Annual Meeting of European Academy of Facial Plastic Surgery Society (EAFPS), London, UK, 23-25 September, 2016.
Facelift: basics (Moderator), Surgical restoration of facial beaty (moderator), Technical details of different facelift techniques and their outcomes (panelist), rejuvenation of ageing face (resident symphosium), Management of nasal dorsum (panelist), Composite plane facelift (video session).
12. FACEISTANBUL 2016, Istanbul, Turkey, June 1-4, 2016, Istanbul, Turkey (Chair of the Meeting and cadaver dissection course).
Browlift (moderator), Correction of specific tip deformities, A new classification and algorithm for saddle nose reconstruction, Pearls to prevent complications in blepharoplasty, Fillers and fat, Crushed cartilage grafts to camouflage irregularities in rhinoplasty, Midfacelifting vs Facelift: Which technique for which patient?
13. Annual Meeting of European Academy of Facial Plastic Surgery Society (EAFPS), Cannes, France, 24-26 September, 2015.
Neck lifting. Open or not to open the neck? (moderator), Non-surgical rejuvenation (moderator), Soft tissue filling: Fat vs. “off-the-shelf” fillers (panelist), Blepharoplasty: avoiding complications (lecture), Facelift vs midfacelift: which technique for which patient (lecture), Rejuvenation of ageing face (symposium for residents).
14. 3rd Congress of European Otorhinolaryngology and Head and neck Surgery, Prague, Czech Republic, June 7-11, 2015.
Blepharoplasty: Pearls to prevent complications (key note lecture), Rhinoplasty for children (key note lecture chair), Facelift: which technique, why ? (Moderator), botox in facial rejuvenation (panelist), concealing irregularities in rhinoplasty (panelist).
15. FACEISTANBUL 2015 Ageing Face Surgery Cadaver Dissection Course, Istanbul, Turkey, May 12-13, 2015 (Chair of the Meeting).
Ageing physiology and facial aesthetics, Botox in facial rejuvenation, Lower eyelid skin muscle flap blepharoplasty, Facelifting: anatomy and techniques, Fillers and fat augmentation, Live botox and filler application on patient
16. 8th Milano Masterclass, Milan, Italy, Mach 22-14, 2015.
Developing individualized approach for saddle nose reconstruction, Tricks to conceal irregularities in rhinoplasty
17. 37th Annual Congress of the European Academy of Facial Plastic Surgery (EAFPS), Mallorca, Spain, September 2-4, 2014.
Midfacelift (lecture), Developing individual approach for facelifting (lecture), Facelifting in different techniques (round table, modarator), Periorbital rejuvenation (round table, moderator), Dissatisfied patient (round table, panelist).
18. American Academy of Facial Plastic and Reconstrucive Surgery 11th International Symposium, New York, USA, May 27-31, 2014.
Surgical rejuvenation of the midface
19. FACEISTANBUL, Ageing Face Meeting and Cadaver Dissection Course, Istanbul, Turkey, May 1-3, 2014 (Chair of the Meeting).
Midfacelift, Subcilliary skin-muscle flap blepharoplasty, upper eyelid blepharoplasty, when less is enough in surgical rejuvenation, which facelift for which patient, picking the right patient for upper face rejuvenation, nonsurgical rejuvenation: patient selection and treatment strategies
20. Palma De Mallorca Facial Plastic Surgery Cadaver Dissection Course, Palma De Mallorca, Spain, December 3-6, 2013.
Ageing physiology, blepharoplasty, midfacelift, facelift, browlift.
21. 35th Annual Congress of the European Academy of Facial Plastic Surgery (EAFPS), Oslo, Norway, August 28- September 1, 2013.
Surgical rejuvenation in midface, Concealing irregularities in rhinoplasty.
22. 24th Congress of the European Rhinologic Society (ERS) and the 31st International Symposium of Infection & Allergy of the Nose (ISIAN), Toulouse, France, June 17- 21, 2012.
Reconstructive issues in nasal and facial plastic surgery, Hard rhinoplasty cases
23. 8th International Federation of Facial Plastic Reconstructive Surgery Society (IFFPRS) Meeting, May 9-12, 2012. Roma, İtaly.
Ageing face surgery, Concealing contour irregularities in rhinoplasty, EAFPS Fellows Clup
24. 3rd International Congress of Rhinology & Facial Plastic Surgery, Tehran, Iran, 4-7 October, 2011.
Different techniques in lower facelift, Belepharoplasty (Indications, techniques, pitfalls), Forhead lift; Endoscopic or bicoronal, Facial prostheses (Indications, techniques, pitfalls), Facial fillers, Midface lift, Techniques to conceal dorsal irregularities in rhinoplasty.
25. 34th Annual Congress of the European Academy of Facial Plastic Surgery (EAFPS), Bruges, Belgium, 1- 4th September 2011.
Brow lift, Crushed cartilage grafts for dorsal irregularities, An algorithm for aging face surgery
26. First Congress of the Confederation of the European Otorhinolaryngology, Head & Neck Surgery, Barcelona, Spain, July 2-6, 2011.
The Failed Rhinoplasty: How To Revise The Nose That Went Wrong
27. Second Middle East Congress on Rhinology and Facial Plastic Surgery (MERC 2010), Tehran, Iran, November 17-19th, 2010.
Concealing dorsal irregularities in rhinoplasty, Revision rhinoplasty, Endoscopic browlift and midfacelift.
28. 32nd Annual Conference of the European Academy of Facial Plastic Surgery, Porto, Portugal, September 3-5, 2009.
Grafts in Rhinoplasty
29. First Meeting of the European Academy of Otolaryngology Head and Neck Surgery (EAORL-HNS), Mannheim, Germany, 27-30 June 2009.
The quest of the ideal nasal profile
30. 20th Congress of the European Rhinologic Society, Istanbul, Turkey, June 18-25, 2004.
Errors and physical limitations of acoustic rhinometry
1. Cakmak O. Clarification regarding the modified finger-assisted malar elevation (FAME) technique. Aesthetic Surgery Journal, 2019; 39 (5), 161-162 (Response by Brian Mendelson, 163-164)
2. Cakmak O, Over-cropped figure obstructing the modified finger-assisted elevation technique, Aesthetic Surgery Journal (in press)
3. Cakmak O, Ozucer B, Modified composite-flap facelift combined with FAME: A cadaver study. Aesthetic Surgery Journal, 2018; 38 (12), 1269-1279. (Commentary by Marc Mani, 1280-1283, Commentary by Brian Mendelson, 1284-1288).
4. Cakmak O, Emre IE, Ozucer B. Surgical approach to the thick nasolabial folds, jowls and heavy neck. Facial Plast Surg. 2018 Feb;34(1):59-65.
5. Cakmak O, Emre IE, Ozkurt FE. Addressing saddle nose deformity-Reply. JAMA Facial Plast Surg. 2016 18(1):75-76.
6. Cakmak O, Emre IE, Ozkurt FE. Identifying septal support reconstructions for saddle nose deformity: The Cakmak Algorithm. JAMA Facial Plast Surg. 2015; 17 (6): 433-439 (Commentary by Rui Xavier, 2016 Jan-Feb;18(1):75)
7. Cakmak O, Babakurban ST, Akkuzu HG, Bilgi S, Ovalı E, Kongur M, Altintas H, Yilmaz B, Bilezikçi B, Yilmaz Celik Z, Yakicier MC, Sahin FI. Injectable tissue engineered cartilage using commercially available fibrin glue. Laryngoscope. 2013;123 (12): 2986-92.
8. Emre IE, Cakmak O. Aging face, an overview – Aetiology, assessment, and management. The Otorhinolaryngologist, 2013; 6(3): 160–166.
9. Cakmak O, Turkoz HK, Polat S, Serin GM, Hizal E, Tanyeri H. Histopathologic response to highly purified liquid silicone injected intradermally in rat’s skin. Aesthetic Plast Surg. 2011; 35(4):538-44.
10. Hizal E, Buyuklu F, Ozer O, Cakmak O. Effects of different levels of crushing on the viability of rabbit costal and nasal septal cartilages. Plast Reconstr Surg 2011; 128(5): 1045-51.
11. Altintas H, Odemis M, Bilgi S, Cakmak O. Long-term complications of polyethylene glycol injection to the face. Aesthetic Plast Surg. 2012; 36 (2): 427-30.
12. Buyuklu F, Akdogan MV, Ozer C, Cakmak O. Growth characteristics and clinical manifestations of the paranasal sinus osteomas. Otolaryngol Head Neck Surg. 2011 145 (2), 319-323.
13. Buyuklu F, Hizal E, Yilmaz Z, Sahin FI, Cakmak O. Viability of crushed human auricular and costal chondrocytes in cell culture. J Cranio Maxillofac Surg, 2011; 39(3):221-5.
14. Cakmak O, Altintas H. A classification for degree of crushed cartilage. Arch Facial Plastic Surg, 2010, 12 (6), 435-436.
15. Babakurban ST, Cakmak O, Kendir S, Elhan A, Quatela VC. Temporal branches of the facial nerve and their relationships with the fascial layers. Arch Facial Plastic Surg, 2010, 12 (1), 16-23.
16. Ulu EM, Cakmak O, Dönmez FY, Büyüklü F, Cevik B, Akdoğan V, Coşkun M. Sinonasal schwannoma of the middle turbinate. Diagn Interv Radiol. 2010 Jun; 16 (2): 129-31.
17. Buyuklu F, Cakmak O, Hızal E, Dönmez FY. Outfracture of the Inferior Turbinate: A Com-puted Tomography Study. Plast Reconstr Surg. 2009, 123(6):1704-1709.
18. Cakmak O. Crushed cartilage grafts. Arch Facial Plast Surg, 2008, 10 (6), 428.
19. Tarhan E, Cakmak O, Ozdemir B, Akdogan V, Suren D. Comparison of AlloDerm, fat, fascia, cartilage and dermal grafts in rabbits. Arch Facial Plastic Surg, 2008, 10 (3): 187-193.
20. Cagici A, Cakmak O, Bal N, Yavuz H, Tuncer İ. Effects of different suture materials on carti-lage reshaping. Arch Facial Plastic Surg, 2008, 10 (2): 124-129.
21. Topal O, Erbek SS, Kıyıcı H, Cakmak O. Expression of metalloproteinases MM-2 and MM-9 in antrochoanal polyps. Am J Rhinol. 2008, 22 (4): 124-129.
22. Erbek SS, Serefhanoglu K, Erbek S, Demirbilek M, Can F, Tarhan E, Turan H, Cakmak O. Clinical subgroups and antifungal susceptibilities in fungal culture-positive patients with chronic rhinosinusitis. Eur Arch Otorhinolaryngol. 2008, 265(7):775-80.
23. Cakmak O, Buyuklu F. Crushed cartilage grafts for concealing irregularities in rhinoplasty. Arch Facial Plastic Surg, 2007, 9 (5): 322-327.
24. Cankurtaran M, Celik H, Coskun M, Hizal E, Cakmak O. Acoustic Rhinometry in Healthy Humans: Accuracy of area estimates, and ability to quantify certain anatomical structures in the nasal cavity. Annals of Otology, Rhinology & Laryngology, 2007, 116 (12), 906-916.
25. Erbek SS, Yurtcu E, Erbek S, Atac FB, Sahin FI, Cakmak O. Proinflammatory cytokine single nucleotide polymorphisms in nasal polyposis. Arch Otolaryngol Head Neck Surg. 2007;133:705-709.
26. Erbek SS, Erbek S, Topal O, Cakmak O. The role of allergy in the severity of nasal polyposis. Am J Rhinol. 2007 Nov-Dec;21(6):686-90.
27. Buyuklu F, Cakmak O. Histological analysis of human diced cartilage grafts. Plast Reconstr Surg. 2007 Jul;120(1):348-9.
28. Ada S, Seckin D, Tarhan E, Buyuklu F, Cakmak O, Arikan U. Eosinophilic ulcer of the tongue. Australas J Dermatol. 2007 Nov 48 (4), 248-50.
29. Erkan AN, Cakmak O, Kocer NE, Yilmaz I. Effects of fibrin glue on nasal septal tissues. 2007 Mar;117(3):491-6.
30. Turkoglu S, Cakmak O, Kaya S, Colak A, Demirhan B. Pathology quiz case 2: Molluscum con-tagiosum. Arch Otolaryngol Head Neck Surg. 2007 Feb;133(2):199, 201.
31. Erbek S, Erbek SS, Tosun E, Cakmak O. A rare case of sarcoidosis involving the middle turbi-nates: an incidental diagnosis. Diagn Pathol. 2006 Nov 21;1:44.
32. Cakmak O, Buyuklu F. Survival of diced cartilage grafts: an experimental study. Plast Reconstr Surg. 2006 Dec;118(7):1658; author reply 1658-9.
33. Cagici CA, Ozer C, Yilmaz İ, Bolat TA, Cakmak O. Solitary polyps of the uncinate process. Ear Nose Throat J. 2007 Feb;86(2):4-6.
34. Erkan AN, Cakmak O, Kayaselcuk F, Koksal F, Ozluoğlu LN. Bilateral parotid tuberculosis. Eur Arch Otorhinolaryngol. 2006 263(5):487-9.
35. Cakmak O, Buyuklu F, Yilmaz Z, Sahin FI, Tarhan E, Ozluoglu LN. Viability of cultured human nasal septum chondrocytes after crushing. Arch Facial Plast Surg. 2005 7(6):406-9,
36. Erkan AN, Cakmak O, Bal N. Frontochoanal Polyp: Case Report. ENT J. 2009, 88(5):E1.
37. Cagici CA, Cakmak O, Hurcan C, Tercan F. Three-slice computerized tomography for the diag-nosis and follow-up of rhinosinusitis. Eur Arch Otorhinolaryngol. 2005 262(9):744-50.
38. Cakmak O, Bircan S, Buyuklu F, Tuncer I, dal T, Ozluoglu LN. Viability of crushed and diced cartilage grafts: a study in rabbits. Arch Facial Plast Surg. 2005 7(1):21-6.
39. Cakmak O, Celik H, Cankurtaran M, Ozluoglu LN. Effects of anatomical variations of the nasal cavity on acoustic rhinometry measurements: a model study. Am J Rhinol. 2005 May-Jun;19(3):262-8.
40. Tarhan E, Coskun M, Cakmak O, Celik H, Cankurtaran M. Acoustic rhinometry in hu-mans:accuracy of nasal passage area estimates, and ability to quantify paranasal sinus volume and osteum size. J Appl Physiol. 2005 99:616-623.
41. Cagici CA, Karabay g, Yilmazer C, Gencay S, Cakmak O. Electron microscopy findings in the nasal mucosa of a patient with stenosis of the nasal vestibule. Int J Pediatr Otorhinolaryngol. 2005 Mar;69(3):399-405.
42. Cakmak O, Tarhan E, Coskun M, Cankurtaran M, Çelik H. Acoustic Rhinometry: Accuracy and Ability to Detect Changes in Passage Area at Different Locations in the Nasal Cavity. Ann Otol Rhinol Laryngol. 2005 114(12):949-57.
43. Buyuklu F, Tarhan E, Cakmak O, Ozgirgin N, Arikan U. Isolated fibrous dysplasia of the sphenoid sinus. Rhinology 2005 43, 152-5.
44. Celik H, Cankurtaran M, Cakmak O. Acoustic rhinometry measurements in stepped-tube models of the nasal cavity. Physics in Medicine and Biology, 49: 371-386, 2004.
45. Akkuzu G, Aydin E, Cakmak O, Akkuzu B, Ozluoglu LN. Pathology quiz case 1. Atypical fibroxanthoma of the auricle. Arch Otolaryngol Head Neck Surg. 130: 238-240, 2004.
46. Yılmaz I, Akkuzu B, Cakmak O, Ozluoglu LN. Misoprostol in the treatment of tinnitus: a double-blind study. Otolaryngol Head Neck Surg. 2004 130: 604-10.
47. Yilmaz I, Cakmak O, Ozgirgin N, Boyvat F, Demirhan B. Complete fistula of the second bran-chial cleft: case report of catheter-aided total excision. Int J Ped Otorhinolaryngol, 68: 1109-1113, 2004.
48. Caylakli F, Buyuklu F, Cakmak O, Ozdemir H, Ozluoglu LN. Ossifying fibroma of the middle turbinate: A case report. Am J Otolaryngol. Sep-Oct;25(5):377-8, 2004.
49. Akkuzu B, Yilmaz I, Cakmak O, Ozluoglu LN. Efficacy of misoprostol in the treatment of tin-nitus in patients with diabetes and/or hypertension. Auris Nasus Larynx. 2004 Sep;31(3):226-32.
50. Cakmak O, Celik H, Cankurtaran M, Buyuklu F, Ozgirgin N, Ozluoglu LN. Effects of paranasal sinus ostia and volume on acoustic rhinometry measurements: a model study. J Appl Physiol. 94: 1527-35, 2003.
51. Cakmak O, Coşkun M, Çelik H, Buyuklu F, Ozluoglu LN. Value of acoustic rhinometry for measuring nasal valve area. Laryngoscope. 113: 295-302, 2003.
52. Cankurtaran M, Çelik H, Cakmak O, Ozluoglu LN. Effects of the nasal valve on acoustic rhi-nometry measurements: a model study. J Appl Physiol. 94: 2166-72, 2003.
53. Caylakli F, Cakmak O, Seckin D, Kayaselcuk F, Demirhan B, Ozluoglu LN. Juvenile hyaline fibromatosis: a case report. Int J Pediatr Otorhinolaryngol. 67: 557-61, 2003.
54. Cakmak O, Yavuz H, Yucel T. Nasal and paranasal sinus schwannomas. Eur Arch Otorhinola-ryngol. 260: 195-7, 2003.
55. Cakmak O, Ergin NT. The versatile autogenous costal cartilage graft in septorhinoplasty. Arch Facial Plast Surg, 4: 172-176, 2002 (Commentary: Arch Facial Plast Surg, 4: 177-179, 2002).
56. Cakmak O, Çeken I, Seçkin D, Yılmaz İ, Akkuzu B, Özlüoğlu LN. Bullous pemphygoid associated with parotid carcinoma. Otolaryngol Head Neck Surg, 127: 354-356, 2002.
57. Cakmak O, Aydın MV, Ergin NT. Isolated sphenoid sinus adenocarcinoma: A case report. Eur Arch Otorhinolaryngol, 259; 266-268, 2002.
58. Cakmak O, Ergin NT, Yılmazer C, Kayaselçuk F, Barutçu Ö. Endoscopic removal of esthesioneuroblastoma. A case report. Int J Ped Otorhinolaryngol, 64; 233-238, 2002.
59. Cakmak O, Çelik H, Ergin T, Sennaroglu L. Accuracy of acoustic rhinometry measurements. Laryngoscope 111: 587-594, 2001.
60. Cakmak O, Shohet MR, Kern EB. Isolated sphenoid lesions. American Journal of Rhinology, 14: 13-19, 2000.
61. Cakmak O, Kutluk T, Akyol MU, Ruacan Ş. Angiocentric lymphoma involving the temporal bone: A rare presentation. European Archives of Otorhinolaryngology, 256: 262-265, 1999.