Currently, the wish to optimize facial esthetics—in the context of a dysfunctional occlusion or not—has become the main motivation for orthognathic surgery in many cases. In this context, considering that protrusive faces are advised more attractive and that the lack of skeletal support accelerates the aging process, orthognathic surgery will mostly involve a forward movement of the maxillamandibular complex..
Key points
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When an “orthofacial” approach is embraced, surgical planning should focus to improve facial aesthetics, soft tissue support, temporomandibular joint, and upper airway volume, not only regarding occlusal purposes.
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The “Barcelona line (BL) is used to find the most aesthetic sagittal position of the maxilla, where a perpendicular true vertical line through the soft tissue nasion or so-called BL is traced.
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For diagnostic purposes, only a profile smiling picture with the patient in the natural head orientation position suffices to evaluate the relation of the BL with the upper incisor. In the context of surgical planning, the upper incisor should be positioned in or in front of the BL.
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Attractive faces are more protrusive than the cephalometric standards would like to accept.
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The forward reposition of the maxillomandibular complex involves beneficial aesthetic effects because the facial mask is tightened and therefore a reverse facelift is observed with subsequent improvement of nasolabial and labiomental folds and jowl areas.
Introduction
Orthognathic surgery (OS) indications have evolved substantially over the years due to a popular perception of surgery as a safe and predictable procedure, supported by the improvements in the surgical, medical, and orthodontic fields. Although correcting a dysfunctional occlusal and skeletal deformity used to be the key concern and almost exclusive therapeutic goal a few decades ago, nowadays it is clear that OS goes far beyond the mere correction of hard tissues. Its current uses comprise several functional indications, with the aim of correcting—a part from occlusion—also mastication, phonetics, temporomandibular joint disorders, sleep-related breathing disorders, and the avoidance of periodontal damage.
Currently, the wish to optimize facial esthetics—in the context of a dysfunctional occlusion or not—has become the main motivation for OS in many cases. Furthermore, the number of adult patients—not only young adults—who get involved in orthodontic or combined orthodontic-surgical therapy for both functional and/or aesthetic reasons is increasing steadily. It should be highlighted that when a dentofacial deformity (DFD) involves any skeletal hypoplasia of the lower and/or midfacial thirds, the lack of skeletal support accelerates the aging process, because typical unaesthetic facial features may appear precociously, such as poor projection of the lips, the early appearance of a double chin, and deepening of the nasolabial and labiomental folds, among others.
Although the maxillofacial region is the key area of attention when planning an OS procedure, the nose, the malar–midface, and the jawline regions are also critical determinants of overall facial esthetics, because the surgical creation of beauty requires the attainment of a correct balance between these three major facial prominences. Besides, the state-of-the-art treatment of DFDs through OS involves the comprehensive management of both the hard and soft tissues to correct any functional and aesthetic disharmonies of the maxillofacial complex. ,
The Barcelona line: A diagnostic and surgical planning tool
Beauty is a subjective perception conditioned by individual and cultural preferences. Although facial beauty historically has been widely discussed, the contemporary attractive face entails protrusive, angled and defined lines. On the other hand, poor skeletal support of soft tissue manifests with premature facial aging. ,
From this perspective, in 2010, the senior investigator described the “Upper Incisor to Soft Tissue Plane” ( Fig. 1 ) to trace the most aesthetic sagittal position of the maxilla in the context of DFD diagnosis and surgical planning. Nowadays, this tool has been renamed as “Barcelona line (BL) to ease its designation. In brief, after bearing out the natural head orientation (NHO) position of the head, a perpendicular true vertical line through the soft tissue nasion or so-called BL is traced. Then, the upper incisor should be positioned in or in front of the BL, providing upper lip support (based on adequate upper incisor angulation, or an orthodontically well-planned upper incisor position, with respect to the maxillary plane).
Workflow protocol for orthognathic surgery virtual planning
The BL protocol for OS virtual planning is based on a single cone-beam computed tomography (CBCT) scan (iCAT, Imaging Sciences International, Hatfield, PA, USA) of the head of the patient, with intraoral surface scanning of the dental arches using the Lava Scan ST scanner (3M ESPE, Ann Arbor, MI, USA) for subsequent fusion of the two data sets. The data are primarily saved in Digital Imaging and Communications in Medicine format using three-dimensional (3D) software (Dolphin 3D Orthognathic Surgery Planning Software Version 11.8) for computer-assisted simulation surgery.
In addition, facial photographic records are obtained to complete the preoperative study protocol. Patients are previously instructed by trained personnel to achieve the key points of photographic records for OS diagnosis and planning purposes: the patient breathing quietly without swallowing, sitting upright in the NHO position; indicating the patient to look straight ahead at a point in front of them at eye level (looking into a mirror); and the tongue in a relaxed position ( Fig. 2 ).
For accurate virtual surgical planning, the BL protocol consists in a sequence of reproductible steps:
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Definition of the desired final occlusion in the physical dental models.
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Digital scanning of final occlusion and introduction of the 3D software for subsequent fusion with the CBCT data set.
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Virtual head orientation according to the NHO position from the lateral resting facial picture. Then, this is considered the true horizontal line (see Figs. 2 ; Fig. 3 ).
Fig. 3 Virtual planning according to the “Barcelona line,” where the upper incisor is positioned in front of the BL. - 4.
Once the mandibular and maxillary osteotomies are designed, surgical repositioning of the maxillomandibular complex is virtually simulated. From the previously established final occlusion, maxilla and mandible are together positioned into class I.
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The BL is traced: a true vertical line perpendicular to the true horizontal line based on the NHO position is drawn, crossing the soft tissue nasion.
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The maxillomandibular complex is moved all together as a block with its upper incisor in or in front of the BL (see Fig. 3 ); it is extremely important that the upper incisor has the appropriate angulation or a well-orthodontically planned position with respect to the maxillary plane.
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The dental and facial midlines are aligned, and the maxillomandibular complex is repositioned in all spatial planes (pitch, roll, and yaw) to set the virtual treatment objectives.
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Clockwise or counterclockwise (CCW) rotation of the maxillomandibular complex is performed to achieve a proper occlusal plane.
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Adequate projection of the chin is checked. In general terms, pogonion should be in or ahead the BL and the angle between occlusal plane lower incisor–pogonion should be around 90°. So, if necessary, a genioplasty is planned accordingly.
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The exact vertical maxillary positioning is defined intraoperatively ensuring 2 to 3 mm of upper incisor exposure with relaxed upper lips.
Functional and aesthetic orthofacial impact after orthognathic surgery following the Barcelona line protocol
When an “orthofacial” instead of an “orthognathic” approach is embraced, surgical planning should focus to improve the outcomes in terms of facial aesthetics, soft tissue support, temporomandibular joint, and upper airway volume, not merely considering jaws reposition for occlusal correction.
Although achievement of both functional and aesthetic goals has been the main objective of treatment planning of OS, most of the classical cephalometric analyses were centered on the false presumption that occlusion correction will result in ideal facial profiles. However, from the early days, Peck found attractive faces to be more protrusive than the cephalometric standards would like to accept. Since then, several investigators have described different analysis focusing on the maxillary sagittal forward positioning to achieve facial attractiveness. ,
Regarding specifically the advantages of the BL protocol, we should mention that for diagnostic purposes, only a profile smiling picture with the patient in the NHO position suffices to evaluate its relation with the upper incisor, making clinical diagnosis easier and less invasive than radiologic analysis. Besides, the soft tissue Nasion point is not modified by surgery, which eases surgical planning and postoperative follow-up.
When using the BL protocol in Caucasian people, usually a forward maxillomandibular movement is required regardless of the initial occlusal situation of the patient or the amount of maxillomandibular discrepancy. Even most class III patients need some degree of mandibular advancement, as most patients present an underlying maxillary sagittal hypoplasia instead of a mandibular sagittal excess. Mandibular setback only appears to be necessary in a minority of cases, which are mostly coincident with a hemimandibular elongation or hyperplasia, an underlying acromegaly, or in cleft or syndromic patients.
In such cases where mandible setback is required, as it involves both functional and aesthetic drawbacks, CCW rotation of the mandible can be performed in some cases with a relatively prominent mandible. Mandibular CCW rotation can be also combined with setback to minimize the side effects of the latter.
On the other hand, mandibular advancement also presents other functional advantages over its setback, such as better long-term stability and pharyngeal airway enlargement. For the latter, forward movement of the maxillomandibular complex not only pulls forward the anterior pharyngeal wall but also enlarges the oral cavity and thus the tongue is better positioned anteriorly, and finally posterior airway space is less collapsed by the base of the tongue. , In this context, the maxillomandibular advancement has shown to be the most effective option for treating sleep-related breathing disorders in patients with an underlying DFD, with an 87.5% success rate. Specifically, bimaxillary advancement and mandibular occlusal plane changes by CCW rotation are the most significant contributors for upper airway enlargement ( Fig. 4 ).
