Int. J. Oral Maxillofac. Surg. 2017; 46: 586–589 http://dx.doi.org/10.1016/j.ijom.2017.01.020, available online at http://www.sciencedirect.com Technical Note Cosmetic Surgery 1,2 A. Valls-Ontan˜ o´ n , C. Mezquida- 1 1,2 Ferna´ndez , R. Guijarro-Martı´nez , Three-dimensional surgical 1,2 F. Herna´ndez-Alfaro 1 Institute of Maxillofacial Surgery, Teknon Medical Centre, Barcelona, Spain; 2 planning and simulation to Department of Oral and Maxillofacial Surgery, Universitat Internacional de Catalunya, Sant Cugat del Valle`s, Barcelona, improve surgical accuracy and Spain reduce invasiveness of cranioplasties A. Valls-Ontan˜o´n, C. Mezquida-Ferna´ndez, R. Guijarro-Martı´nez, F. Herna´ndez- Alfaro: Three-dimensional surgical planning and simulation to improve surgical accuracy and reduce invasiveness of cranioplasties. Int. J. Oral Maxillofac. Surg. 2017; 46: 586–589. ã 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. Patients with too large a frontal prominence may suffer discomfort and subsequent self-esteem problems. The case of a 29-year-old male with a prominent forehead is presented. After three-dimensional (3D) virtual simulation of the procedure, a stereolithographic model of the skull and a surgical cutting guide were fabricated. The forehead recontouring and reconstruction procedure was performed under general anaesthesia and the postoperative course was uneventful. At the 12-month postoperative follow-up, clinical and radiographic documentation confirmed softening of the frontal prominence from 14.48 mm to 8.56 mm, a Key words: frontal sinus; frontal bone; fore- nasofrontal angle increase of 22 , and overall high patient satisfaction. The head; cone beam computed tomography; sur- proposed workflow results in greater surgical precision, shorter reconstruction gical planning software; surgical cutting guide; times, reduced patient morbidity due to a reduced risk of dural exposure cranioplasty; aesthetic surgery; feminization. and postoperative infection, and overall higher predictability and patient satisfaction. Available online 21 February 2017 1 Comprehensive aesthetic analysis of the or thick supraorbital ridges. Consequent- come pneumatized and reach their full size 3 upper facial third entails consideration of ly, the nasofrontal angle is often acute in at puberty. Lee et al. described frontal three key-areas: the frontal sinus promi- men, while it is much more obtuse in sinus anatomy and sex variations from nence, the superciliary and supraorbital women in response to very little — if computed tomography (CT) scan images 2 ridge, and the nasoglabellar angle. In par- any — brow fullness. and concluded that males have greater ticular, a prominent frontal vault is an The frontal sinuses are the last facial dimensions in most frontal sinus measure- inherent masculine characteristic that sinuses to achieve complete development. ments: male foreheads were characterized may be due to large frontal sinuses and/ After slow progressive growth, they be- by a more acute nasofrontal angle (119.9 0901-5027/050586 + 04 ã 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Three-dimensional surgical planning and simulation to improve surgical accuracy and reduce invasiveness of cranioplasties 587 vs. 133.5 ), a steeper posterior forehead inclination (À7.2 vs. À3.5 ), and a wider glabella (44.4 mm vs. 33.9 mm), frequent- ly protruding beyond the ideal forehead 4 slope line (51% vs. 30%). According to the classification of Urken et al., an abnormally large frontal sinus may be due to three different conditions: hypersinus, pneumosinus dilatans, and 5 pneumocele. A hypersinus is an enlarged frontal sinus that does not extend beyond the normal limits of the frontal bone and has normal wall thickness. Pneumosinus dilatans is a situation where the sinus expands abnormally beyond the normal limits of the frontal bone, yet the bony walls of the sinus are of normal thickness. Finally, an aerated sinus with variable thinning of its walls characterizes a pneu- mocele. This condition differs from the two previous ones in that it is considered a pathological status secondary to a sinus 3 drainage disturbance. Fig. 1. Preoperative and postoperative pictures illustrating the successful result. While the chief patient complaint is an annoying prominent forehead, related symptoms include local painful pressure, CAT scanner; Imaging Sciences Interna- orbital rim were exposed, both supraorbit- nasal bleeding, anosmia, diplopia, and tional, Inc., Hatfield, PA, USA) and al neurovascular bundles were dissected headache. In women with bossing fore- showed diffuse enlargement of both fron- carefully. The limits of the frontal sinus heads, substantial aesthetic disharmony tal sinuses. No signs of intracranial or were marked on the anterior cortical wall 1–3 and facial masculinization may result. orbital involvement were detected. Simi- with the help of the prefabricated surgical Likewise, men with too large a frontal larly, a sinus pathology was ruled out. cutting guide (Fig. 2). Then, the anterior prominence may refer to discomfort and Metric analysis was performed at the fa- wall was removed integrally using a pie- self-esteem problems. Surgical reshaping cial midline. The frontal sinus height, zoelectric device (Implant Center 2; Sate- of the upper facial third is an effective width, and depth measured 36.47 mm, lec-Acteon Group, Tuttlingen, Germany) solution to the aforementioned clinical 58.84 mm, and 14.58 mm, respectively. (Fig. 3). The tip of the piezoelectric saw and psychological symptoms. The thickness of the anterior table was was inclined obliquely at an angle greater The aim of this article is to describe a 2.24 mm. Despite mild thinning of the than 45 to the bone surface, taking care to specific workflow for three-dimensional anterior cortical wall, the anatomical de- avoid any perforations and subsequent (3D) planning and execution of forehead formity was categorized as a pneumosinus dural exposure. The mucosa of the sinus recontouring and reconstruction, to ana- dilatans owing to frontal sinus expansion was removed, and both frontonasal ducts lyze its advantages and limitations, and to beyond the normal limits of the frontal and frontal sinuses were obliterated with discuss potential possibilities for future bone with signs or symptoms of sinus fibre-reinforced calcium phosphate (Nor- improvement. drainage disturbance. ian CRS; Synthes Inc., West Chester, PA, Primary DICOM files (digital imaging USA). The previously removed anterior and communications in medicine) from wall fragment was meticulously sculpted Methods the CBCT analysis were imported into and flattened with a surgical burr (round A 29-year-old male was referred to the specific treatment planning software (Sim- cutting, 6-mm diameter head) and then department of oral and maxillofacial sur- Plant O&O version 13.0; Dentsply, Leu- repositioned. The sharp edges of the repo- gery of a tertiary hospital complaining of a ven, Belgium). After careful manual prominent forehead and self-esteem pro- segmentation of the raw dataset, the 3D blems related to his facial appearance skull model of the patient was exported in . (Fig. 1). The patient was otherwise asymp- stl (stereolithography file) format in order tomatic and denied any symptoms consis- to fabricate a stereolithographic model. tent with sinus disease. The remainder of The complete forehead recontouring and his medical history was unremarkable, reconstruction procedure was simulated with no history of trauma, infectious rhi- virtually. The virtual plan was reproduced nitis, or allergies. in the stereolithographic skull model, and Physical examination revealed a prom- a surgical cutting template was fabricated. inent frontal vault and an acute nasofrontal Under general anaesthesia, the frontal angle. Otorhinolaryngological, ophthal- bossing was reached through a coronal mological, hormonal, and neurological approach. The incision was performed in Fig. 2. Intraoperative picture: limits of the examinations were normal. an oblique fashion in order to preserve the frontal sinus marked on the anterior cortical A cone beam computed tomography maximum amount of hair follicles. Once wall with the help of the prefabricated surgical (CBCT) examination was performed (i- the frontal bone, glabella, and superior cutting guide. 588 Valls-Ontan˜o´n et al. surface matching. To this effect, the ante- anatomy. Individuals can be classified into rior and middle cranial fossae served as two major categories based on their fore- 1 reference landmarks. Two- and three-di- head anatomy. Group I comprises sub- mensional morphometric comparisons jects with a thick cortical bone over the (Fig. 4) revealed softening of the frontal frontal bulge, the sinuses meanwhile being bossing from 14.48 mm to 8.56 mm, and of normal or small size. In these patients, an increase in the nasofrontal angle from sculpting using a burr without penetrating 110 to 132 . the frontal sinus is sufficient. Group II comprises subjects in whom the frontal protuberance is associated with compara- Discussion Fig. 3. Intraoperative picture: frontal bone tively thin bone over the frontal sinuses. In anterior wall osteotomy. Radiological evaluation with CT or CBCT these cases, an anterior wall frontal bone permits a comprehensive evaluation of the osteotomy is required, and the anterior sitioned anterior wall bone were polished patient’s anatomy