Protocol for facially guided digital orthodontic diagnosis and treatment planning

•A fully integrated interdisciplinary workflow to solve complex treatments is proposed.•This protocol establishes a comprehensive digital orthodontic diagnosis.•It guides the multidisciplinary team through the planning and treatment phases.•Treatment results are verified using 3D superimposition, photography, and videography.•This workflow allows the multidisciplinary team to stay on track and save time. Using a digital workflow in orthodontics and interdisciplinary dentistry undoubtedly benefits both the patient and professional. This 9-step protocol guides orthodontists through an interdisciplinary treatment planning and execution. First, it establishes an exhaustive digital diagnosis and then formulates an interdisciplinary digital treatment plan with 3-dimensional (3D) goals. Finally, objective verification of the treatment results occurs through 3D superimposition. This 9-step protocol proposes a fully integrated workflow platform by providing a digital, 3D, clear planning protocol for the interdisciplinary team. It gives them a clear vision of successfully managing the patient from start to finish. It is versatile, logical, and methodical and can be applied to any clinical situation involving orthodontics. Using a digital workflow in orthodontics and interdisciplinary dentistry undoubtedly benefits both the patient and professional. This 9-step protocol guides orthodontists through an interdisciplinary treatment planning and execution. First, it establishes an exhaustive digital diagnosis and then formulates an interdisciplinary digital treatment plan with 3-dimensional (3D) goals. Finally, objective verification of the treatment results occurs through 3D superimposition. This 9-step protocol proposes a fully integrated workflow platform by providing a digital, 3D, clear planning protocol for the interdisciplinary team. It gives them a clear vision of successfully managing the patient from start to finish. It is versatile, logical, and methodical and can be applied to any clinical situation involving orthodontics. As the digital age of dentistry continues to flourish, it has never been more important to have protocols to guide dentists through interdisciplinary treatment planning and execution using the latest technology and software. Digital workflows have reduced patient chair time and improved treatment accuracy. In orthodontics, it has revolutionized the visualization of potential treatment outcome depictions for patients willing to consider orthodontic treatments. Nowadays, after just a single visit for record taking, the diagnosis can be made, and the full treatment can be planned with virtual simulations at every step.1Farronato G Galbiati G Esposito L Mortellaro C Zanoni F Maspero C Three-dimensional virtual treatment planning: presurgical evaluation.J Craniofac Surg. 2018; 29: e433-e437Crossref PubMed Scopus (23) Google Scholar Furthermore, a digital workflow facilitates collaboration and virtual records sharing between dental specialists in an interdisciplinary environment and allows open and transparent communication with the patient.2Lv L He W Ye H Cheung K Tang L Wang S et al.Interdisciplinary 3D digital treatment simulation before complex esthetic rehabilitation of orthodontic, orthognathic and prosthetic treatment: workflow establishment and primary evaluation.BMC Oral Health. 2022; 22: 34Crossref PubMed Scopus (8) Google Scholar Establishing a comprehensive diagnosis is crucial when a patient requires extensive treatment. With digital software, treatment simulations can show the patient an approximation of the desired treatment results before the treatment begins and then at every step. A key focus of this protocol is facial harmony, especially considering that the chief complaint in >80% of patients is to improve facial and smile esthetics.3Di Blasio M Vaienti B Pedrazzi G Cassi D Magnifico M Meneghello S et al.Are the reasons why patients are referred for an orthodontic visit correct?.Int J Environ Res Public Health. 2021; 18: 5201Crossref PubMed Scopus (7) Google Scholar In this sense, simulations and visualizations of the potential treatment alternatives can be useful in improving patient adherence and overall acceptance of treatment goals. This is a key component of a continuous informed consent process and reduces the likelihood of legal claims.4Venugopal A Flores-Mir C Vaid NR Autonomy and consent in this era of unconscious priming.Am J Orthod Dentofacial Orthop. 2022; 161: e297-e302Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar From the point of view of each interdisciplinary team member, by having a protocol to guide them through the treatment, each phase of the treatment can be performed correctly, and at the end of the treatment, facial harmony between soft and hard tissues can be achieved. This versatile 9-step protocol aims to guide orthodontists in treating their patients no matter the treatment that is planned, whether orthodontic alone or with a restorative or surgical component.5Ferrando Cascales R Ferrando Cascales A Temporización en ortodoncia y odontología restauradora para casos de rehabilitación completa en dientes desgastados. [Temporarization of worn down teeth in full mouth reconstruction cases in orthodontics and restorative dentistry].Ortodoncia Española. 2019; 57: 33-41Google Scholar It is valid for any malocclusion, regardless of age or treatment required, as a digital workflow easily integrates different treatment types.6Ebker T Korn P Heiland M Bumann A Comprehensive virtual orthognathic planning concept in surgery-first patients.Br J Oral Maxillofac Surg. 2022; 60: 1092-1096Abstract Full Text Full Text PDF PubMed Scopus (2) Google Scholar It aims to address the lack of a fully integrated interdisciplinary workflow to solve complex orthodontic treatment.2Lv L He W Ye H Cheung K Tang L Wang S et al.Interdisciplinary 3D digital treatment simulation before complex esthetic rehabilitation of orthodontic, orthognathic and prosthetic treatment: workflow establishment and primary evaluation.BMC Oral Health. 2022; 22: 34Crossref PubMed Scopus (8) Google Scholar,7Mirabella D MacCa U Pancari C Giunta G Lombardo L Detailed three-dimensional orthodontic tooth repositioning to improve restorative outcome.Angle Orthod. 2022; 92: 415-425Crossref PubMed Scopus (2) Google Scholar,8Prado N Hosni S Darcey J Aminian A Malik O Smile makeover treatments.Br Dent J. 2022; 233: 391-396Crossref PubMed Scopus (2) Google Scholar This step aims to collect an exhaustive series of digital records. A full series of facial photographs are taken in the NHP, followed by a series of intraoral photographs. The orthodontist uses judgment to find this position, ensuring that the patient is relaxed and looking into the distance at a point at the same level as their eyes. Digital scans are then performed on the maxillary and mandibular arch and the occlusion of the patient. When the patient has a stable bite, the occlusal scan will be taken with the patient in maximum intercuspation. If the patient presents an unstable bite, the centric relationship can be found, recorded using a wax registration, and then scanned. Cone-beam computed tomography (CBCT) imaging can provide vast information; however, it is up to the clinician to decide if and when it is necessary. CBCT aids in the superimposition of facial photographs with digital scans, mounting the virtual articulator, segmenting the roots of the teeth, and assessing the midface and lower face. The limits of any treatment and how much tooth movement is anatomically possible can also be assessed using CBCT.9Hirschhaut M Weinstein C Flores-Mir C An Introduction to the systematic evaluation and management of complex malocclusions.Semin Orthod. 2024; (in press)Abstract Full Text Full Text PDF Scopus (0) Google Scholar Without a CBCT, superimposition of the NHP photographs with intraoral scans can still be performed, and a semiadjustable virtual articulator can still be mounted. NHP photographs and digital scans are considered mandatory for this protocol. A CBCT may be chosen on a case-by-case basis. If a CBCT is not performed, then panoramic or lateral cephalometric x-rays can be performed instead. Once all the records have been obtained, the digital scans can be superimposed onto the NHP photographs using a software package such as NemoCeph (Nemotec SL, Madrid, Spain). If a CBCT was taken, it could be superimposed onto the photographs using the same software—landmarks identified in the CBCT reconstruction aid in the superimposition process. The key in this stage is to obtain the precise orientation of the STL and DICOM files on the basis of the NHP. Correct orientation of the digital records facilitates accurate determination of desired movements. The next step of the protocol involves analyzing crowding or spacing in both arches. The presence or absence of crowding in the maxillary arch guides the first stages of the treatment. On the basis of this measurement, it may be determined that treatments such as extractions or skeletal or dental expansion are required. In some patients, the magnitude of the sagittal and vertical facial imbalances necessitates considering orthognathic surgery to reach reasonable and stable results. Next, we can observe the occlusal relationship using the virtual articulator. This includes interferences and the occlusal contacts present during protrusive and lateral movements. The virtual articulator is mounted on the basis of the CBCT reconstructions of the condyles, glenoid fossa, and cranial base and all 3 parts of the intraoral scan (maxillary arch, mandibular arch, and interocclusal). If CBCT imaging is unavailable, then a semiadjustable virtual articulator can still be mounted with the intraoral scans orientated and aligned with the NHP photographs using software such as NemoCeph (Nemotec SL). Furthermore, the curves of Wilson and Spee can be measured to determine whether flattening the curves is required and what space is required to do this. A 2D cephalometric analysis is performed to determine the patient's current situation and establish the measurements outside the normal ranges. First, the hard tissues are analyzed to determine the patient's facial pattern and skeletal imbalances. A lateral cephalometric analysis is required (ie, Ricketts, Steiner, Jarabak, and McNamara analysis). After this, an additional analysis is performed to provide information on the soft tissue structures and their projection to the true vertical line. An Arnett analysis is suggested,10Arnett GW Jelic JS Kim J Cummings DR Beress A Worley CM et al.Soft tissue cephalometric analysis: diagnosis and treatment planning of dentofacial deformity.Am J Orthod Dentofacial Orthop. 1999; 116: 239-253Abstract Full Text Full Text PDF PubMed Google Scholar or the Ayala method if surgery is planned.11Ayala J Tratamiento ortodóncico-quirúrgico: un nuevo método de planificación [Orthodontic-surgical treatment: a new planning method].Rev Española Ortod ISSN. 2005; 35: 293-314Google Scholar The key in this step of the protocol is to first determine the desired position of the maxillary central incisors from a 2D sagittal view (following Arnett's method) before transferring this position to 3-dimensional (3D) in the next step of the protocol. This forms an important part of the treatment planning as these teeth will be virtually moved first. Their vertical position regarding the upper lip is a crucial consideration. After the lateral cephalometric analysis, a VTO is performed with attention to crowding and cephalometric discrepancy. The desired projection of the maxillary central incisor and the interincisal angle can be visualized. If surgical correction is considered necessary to achieve the amount of dental movement required, an STO can be performed after a method such as Ayala's method. Now, the maxillary central incisor position in VTO/STO (2D) is transferred to SETUP (3D) using the most incisal point. At this stage, work continues from the patient's lateral view. Therefore, the critical measurement is the anteroposterior and vertical position of the central incisors. Now, the virtual movement of the maxillary teeth can begin in the sequence: central incisors to lateral incisors to canines to premolars to molars. The maxillary central incisor in the most unfavorable position will be moved first, followed by the contralateral central incisor. Simple rotations can then be planned once the maxillary teeth correct anteroposterior and vertical position has been achieved. Planning the movements of the maxillary arch in this sequence enables the orthodontist to achieve a harmonic arch shape. At the start of this step, attention shifts from the lateral view of the patient to the frontal view, whereby a frontal facial analysis is performed. This step considers 3 key factors: maxillary transverse dimension, occlusal plane transverse angulation (canting), and midlines' symmetry. First, the midline is corrected, then canting, and finally, the transverse dimension of the maxilla. During this stage, techniques, including maxillary expansion (either tooth- or bone-anchored), temporary anchorage devices, etc, may be planned to achieve a desired transversal result for the maxilla and maxillary dentition. The arch contour should be parallel to the smile line. Now that the future position of the maxillary dentition has been chosen, the focus of the orthodontist moves to the mandibular arch. Once again, planning moves in a distal direction from tooth to tooth. The mandibular central incisors are placed in a correct overbite and overjet with maxillary antagonists. Then, the rest of the mandibular teeth are virtually moved in the sequence: central incisors to lateral incisors to canines to premolars to molars. Similar to the maxillary arch, once the correct anteroposterior positions have been planned, the virtual position of each tooth is corrected to give the desired arch shape. At the end of the protocol's stage, a functional occlusion should have been established. A Bolton analysis is performed to determine a correct relationship between both arches. If this relationship is incorrect, alterations such as interproximal reduction or composite build-ups can be planned. Now that the virtual movement of the maxillary and mandibular teeth has been completed, the position of each tooth can be analyzed and compared with the initial positions. On the basis of the results of this analysis, tooth movement complexity becomes clear to reach the overall objectives. The choice of mechanics or technique is guided by the orthodontist's expertise and the strengths and weaknesses of the available approaches. During this final step, an analysis of the final results is performed. Moreover, 2D superimpositions such as pretreatment and posttreatment lateral cephalometric analysis can provide helpful information regarding the treatment success but not exact quantitative values. To quantify the results and provide exact numerical discrepancies, a 3D superimposition using a stable anatomic reference can be performed using a pretreatment and posttreatment STL file. The superimposition of STL files is helpful in tracking the results of dental movements. The superimposition of DICOM files also has value in tracking growth and the results of surgical treatments. Finally, it must be mentioned that photography and videography are very powerful tools that allow orthodontists to verify the results of their treatment. Given that this protocol is facially guided, the final result must be esthetically acceptable from the patient's perspective. Videos of the patient talking and smiling can be taken to provide valuable information on conversational esthetics, which may not be provided by traditional static imaging. Figure provides examples of six cases were the 9-step protocol was used. This protocol provides the orthodontist and interdisciplinary team with a clear vision of how to treat patients successfully. It addresses the lack of a fully integrated, interdisciplinary, 3D proposed digital workflow for orthodontists working in an interdisciplinary team. Working exclusively in a digital environment usually saves chair time, reduces necessary physical storage space, and allows easy and fast collaboration between professionals. The versatility of this protocol means that it is valid for any patient, whether orthodontic, surgical, or restorative, regardless of the required treatment. It incorporates all the elements of a traditional orthodontic analysis: record taking, teeth models, cephalometric analysis, and VTO, but introduces digitalization at each step, creating a modern take on the traditional method. The protocol's first key is to position the patient's head in its natural position, facilitating an accurate and repeatable analysis. Weber et al12Weber DW Fallis DW Packer MD Three-dimensional reproducibility of natural head position.Am J Orthod Dentofacial Orthop. 2013; 143: 738-744Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar specifically investigated the 3D reproducibility of NHP and stated that it is reproducible in the sagittal, coronal, and axial planes. CBCT imaging is a valuable tool in modern orthodontics, providing 3D information that 2D methods cannot. In this protocol, CBCT imaging allows for the segmentation of each tooth, including the roots, which allows for precise planning of tooth movements, including root torque.13Cui Z Fang Y Mei L Zhang B Yu B Liu J et al.A fully automatic AI system for tooth and alveolar bone segmentation from cone-beam CT images.Nat Commun. 2022; 13: 2096Crossref PubMed Scopus (102) Google Scholar For this protocol, a CBCT is suggested in the following situations: adults with periodontal problems, patients with temporomandibular joint disorder (TMD), patients in which a change in vertical dimension is planned, and patients with severe crowding but with the possibility to treat without extractions. The superimposition procedure performed in step 2 has been described and used in different fields of dentistry, especially in digital smile design protocols. Christian Coachman uses 3 facial reference lines to aid in this superimposition: interpupillary line, commissure lines, and facial midline.14Coachman C Sesma N Blatz MB The complete digital workflow in interdisciplinary dentistry.Int J Esthet Dent. 2021; 16: 34-49PubMed Google Scholar Many software packages use artificial intelligence to perform this procedure by identifying landmarks such as the nasion.15Andriola FO Haas Junior OL Guijarro-Martínez R Hernández-Alfaro F Oliveira RB Pagnoncelli RM et al.Computed tomography imaging superimposition protocols to assess outcomes in orthognathic surgery: a systematic review with comprehensive recommendations.Dentomaxillofac Radiol. 2022; 5120210340Crossref PubMed Scopus (17) Google Scholar In step 3 of the protocol, functional problems such as interferences, occlusal stability, and lack of correct canine guidance are diagnosed. A virtual articulator can be used for patients requiring simple orthodontic treatment. Hsu et al16Hsu MR Driscoll CF Romberg E Masri R Accuracy of dynamic virtual articulation: trueness and precision.J Prosthodont. 2019; 28: 436-443Crossref PubMed Scopus (33) Google Scholar reported a <100 µM deviation between a classic mechanical articulator and the virtual alternative. In patients requiring complex orthodontic treatment, such as those requiring interdisciplinary treatment by orthodontists and prosthodontists or those with TMD, a fully adjustable anatomic articulator can be used.17Bapelle M Dubromez J Savoldelli C Tillier Y Ehrmann E Modjaw® device: analysis of mandibular kinematics recorded for a group of asymptomatic subjects.Cranio. 2021; 2021: 1-7Crossref Scopus (28) Google Scholar It should be noted that using a virtual articulator vastly simplifies and shortens the workflow, eliminates the need for physical storage space, facilitates the quick sharing of information between dentists, and is accurate.18Lin H Pan Y Wei X Wang Y Yu H Cheng H Comparison of the performance of various virtual articulator mounting procedures: a self-controlled clinical study.Clin Oral Investig. 2023; 27: 4017-4028Crossref PubMed Scopus (5) Google Scholar In orthodontic-surgical treatment, Ayala places great importance on facial esthetics in his analysis, in which he works from the outside—first planning the final situation for the soft tissues and, subsequently, the hard tissues.11Ayala J Tratamiento ortodóncico-quirúrgico: un nuevo método de planificación [Orthodontic-surgical treatment: a new planning method].Rev Española Ortod ISSN. 2005; 35: 293-314Google Scholar The position of the upper lip is determined first, which is placed 2 mm in front of the true vertical line, varying to 3-4 mm in female patients. This guides the future position of the maxillary teeth. A benefit of working in this sequence is that movements in the teeth or bony structures are not always fully transmitted to the soft tissues. Regarding the future position of the maxillary central incisors, Arnett's method is followed, whereby the central incisors are placed with 3.9 mm of exposure at rest in males and 4.7 mm in females.10Arnett GW Jelic JS Kim J Cummings DR Beress A Worley CM et al.Soft tissue cephalometric analysis: diagnosis and treatment planning of dentofacial deformity.Am J Orthod Dentofacial Orthop. 1999; 116: 239-253Abstract Full Text Full Text PDF PubMed Google Scholar According to Arnett, showing 2 mm of gingival tissue above the maxillary anterior teeth is acceptable when smiling. Before starting the treatment (step 8), the orthodontist must choose the mechanics and techniques they will use to achieve the desired movements on the basis of the patient's diagnosis and the practitioner's expertise. To make this choice, it must be determined whether the amount of planned movement is realistic, stable long-term, and achievable. If not, then performing a camouflage or surgery may be considered. Typically, severe skeletal discrepancies would be treated surgically, and mild-moderate discrepancies would be treated with camouflage or growth modification in interceptive orthodontics.19Kawai N Watanabe M Shibata M Horiuchi S Fushima K Tanaka E Treatment decision of camouflage or surgical orthodontic treatment for skeletal Class III patients based on analysis of masticatory function.J Dent Sci. 2022; 17: 822-830Crossref PubMed Scopus (2) Google Scholar Once the actual tooth movements have been completed, the results must be analyzed. This protocol is facially guided; therefore, facial esthetics and harmony are key metrics when determining the success of the treatment. First, it must be determined whether the chief complaint has been resolved. Then, pretreatment and posttreatment STL scans can be superimposed to validate the results objectively by determining whether the actual movement in each tooth matches the planned movement. Using algorithm-based analysis to superimpose digital dental models, Ganzer et al20Ganzer N Feldmann I Liv P Bondemark L A novel method for superimposition and measurements on maxillary digital 3D models—studies on validity and reliability.Eur J Orthod. 2018; 40: 45-51Crossref PubMed Scopus (40) Google Scholar measured tooth movements accurately to 0.0225 mm and rotations accurately to 0.0291°. Ideally, the patient must have a healthy temporomandibular joint complex free of pain or pathology with balance and harmony between the bones and muscles. Andrews's 6 keys should be met to ensure the patient has a stable, functional occlusion.21Andrews LF The six keys to normal occlusion.Am J Orthod. 1972; 62: 296-309Abstract Full Text PDF PubMed Scopus (790) Google Scholar The patient must have adequate periodontal health, free from osseous or gingival defects.22Alsulaimani L Alqarni H Akel M Khalifa F The orthodontics-periodontics challenges in integrated treatment: a comprehensive review.Cureus. 2023; 15: e38994PubMed Google Scholar The orthodontist must also endeavor to achieve a stable result to avoid relapse. To prevent relapse, fixed or removable retention should be considered.23Padmos JAD Fudalej PS Renkema AM Epidemiologic study of orthodontic retention procedures.Am J Orthod Dentofacial Orthop. 2018; 153: 496-504Abstract Full Text Full Text PDF PubMed Google Scholar Having stated what can be ideally reached, the reality is that some multidisciplinary treatments, especially in older patients, may only reach reasonable occlusal, periodontal, and functional goals.9Hirschhaut M Weinstein C Flores-Mir C An Introduction to the systematic evaluation and management of complex malocclusions.Semin Orthod. 2024; (in press)Abstract Full Text Full Text PDF Scopus (0) Google Scholar Some pretreatment problems preclude ideal results. Patients with previous active degenerative TMD may only transition to a passive stable status if they are not returned to a perfect balance. Some previous periodontal problems would be controlled and stability reached, but perfect periodontal coverage would be unreasonable. If, during the initial consultation, the patient presents with TMD, periodontal problems, or teeth with an uncertain prognosis, a stable health situation should first be sought. After this, the protocol can be restarted with the acquisition of new records, and a new SETUP can be performed. The logical and methodical nature of the 9-step protocol keeps the interdisciplinary team members on track throughout the treatment. It can also act as a checklist that can be followed to ensure, first, that a comprehensive diagnosis has been established, second, that an achievable treatment plan has been made, and, finally, that the result is objectively satisfactory on the basis of numerical parameters and in terms of facial esthetics and patient perception.