EditorialEngineering Solutions for Cranio-Maxillo-FacialRehabilitation and Oro-Dental Healthcare

Ziyad S. Haidar ,1,2,3,4 Lucy Di-Silvio,5 Ziad E. F. Noujeim ,6 John E. Davies,7

Frederic Cuisinier,8 and Avijit Banerjee9

1BioMAT’X, Universidad de los Andes, Santiago, Chile2Programa de Doctorado en BioMedicina, Facultad de Medicina, Universidad de los Andes, Santiago, Chile3Centro de Investigacion e Innovacion Biomedica, Universidad de los Andes, Santiago, Chile4Facultad de Odontologıa, Universidad de los Andes, Santiago, Chile5Department of Biomaterials and Biomimetics, King’s College London, London, UK6Department of Oral Medicine and Maxillofacial Radiology, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon7Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada8Laboratoire Bioingenierie et Nanosciences, Universite de Montpellier, Montpellier, France9Centre for Oral and Craniofacial Sciences, King’s College London, London, UK

Correspondence should be addressed to Ziyad S. Haidar; zhaidar@uandes.cl

Received 12 May 2019; Accepted 12 May 2019; Published 18 June 2019

Copyright © 2019 Ziyad S.Haidar et al.#is is an open access article distributed under theCreative CommonsAttribution License,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Oro-dental health is an essential component of good overallhealth and well-being, and consequently, good oral anddental health is indeed a fundamental human right, part ofthe main role, and goal of the dental profession with all itsinterdisciplinary and multidisciplinary subspecialties to helpthe population achieve a stable and healthy craniomax-illofacial complex. Hence, identifying challenges and op-portunities needs to be in the forefront of our priorities,especially considering the mounting ageing population andswelling demand for oro-dental healthcare, products, ser-vices, and alternative solutions. It is noteworthy herein thatthis agrees with and supports the global 2020 vision of theFDI (Federation Dentaire Internationale) World DentalFederation, the world’s leading dental professional organi-zation, on oral and dental health, where it is proposed andurged to expand the role of existing oral and dentalhealthcare professionals and foster fundamental researchand translational technologies, to better mitigate the impactsof socioeconomic dynamics, a cornerstone for the projectionof this special issue.

In brief, innovative engineering solutions that incorporateadvanced biomaterials, nanobiotechnology, three-dimensionalprinting, computer assistance, and robotic systems offer huge

potential for augmenting and improving the functional andesthetic craniomaxillofacial and oro-dental health profile ofpatients. A good example, perhaps, is nanoDentistry, clearlymultidisciplinary and interdisciplinary, building on existingknowledge and accruing expertise in different scientific andtechnological fields, seeking persistent refinement of tradi-tional approaches, via the development and/or incorporationof advanced biomaterials, new functional tools, and pharma-cological formulations to improve overall oro-dental practiceand care. While slowly evolving, nanoDentistry is expected toprovide dentists and surgeons with more precision-made andtailored materials, drugs, and equipment, by which safety,esthetics, function/efficacy, and patient compliance are en-hanced. Due to the complex nature of such “outside-the-box”(or even “no-box”) healthcare-related engineering problem–solution technologies, they have attracted experts from physics,chemistry, biology, materials science, pharmaceutics, robotics,and bioengineering, as well as the industry. #e ultimatum isimproved overall healthcare and well-being with a positiveimpact on socioeconomics and quality of life.

Hence, this special issue is intended to bring togethera collection of original and state-of-the-art works in oro-dental and craniomaxillofacial healthcare and related

HindawiJournal of Healthcare EngineeringVolume 2019, Article ID 5387305, 3 pageshttps://doi.org/10.1155/2019/5387305

topics to exhibit the latest ideas, concepts, findings,achievements, and future projections and promoteawareness of the rapidly evolving and enabling multi-disciplinary technology, thereby encouraging a fruitfuldialogue to bridge the gap between engineering anddentistry (including subspecialties, extending to the headand neck) for research and innovation collaborationacross the fields to address the critical and urgentbiodental/biomedical concerns. In particular, this specialissue assembles six original contributions presentingrecent advances in biomechanical properties of peri-odontal tissues and metal-based biomaterials, as well asstimulating mathematical modeling methods as funda-mental and expedited analytical tools, for clinical use.Different areas of engineering solutions, once more,clearly support the previously mentioned growing needand our hope to bridge the disciplinary communicationand collaboration gap, through this contribution.

In no particular order, the paper by C. Sinescu et al.entitled “Mechanical Properties of the Periodontal Systemand of Dental Constructs Deduced from the Free Responseof the Tooth” explores the biomechanical behavior of theperiodontal ligament (PDL), the fibrous connective andneurovascular tissue that connects the dentition (cementumpart of the root of an individual tooth) to the surroundingalveolar bone, for proper and healthy support of masticationand nutritional intake, among other key oro-dental func-tions detrimental for an overall general health, well-being,and quality of life. By analyzing clinical and mathematicalstudies, the authors introduce a new method for the eval-uation of biomechanical and elastometric parameters of thetooth-PDL system, using an ultrasound probe, in differentclinical scenarios and conditions.#is study presents a linearmodel in good accordance with physical phenomena thatwould help the dentist and/or prosthodontist (oro-dentalrehabilitation specialist) provide better prosthesis (such ascrowns and bridges) and postoperative care for the patient,to help prevent periodontal and/or masticatory diseases or atleast arrest the adverse consequences on the well-being of thepatient.

L. Bai et al. in the paper entitled “Mechanical Charac-terization of 3D-Printed Individualized Ti-Mesh (Mem-brane) for Alveolar Bone Defects” describe the importanceof sufficient bone volume in implant dentistry, in both thehorizontal and vertical dimensions, and how it plays a vitalrole in achieving long-term esthetic and functional results.Herein, using computer-assisted design and additivemanufacturing technology, a custom-made (personalized/case-by-case) titanium (Ti) mesh is developed. It is deemedsuperior to conventional and commercially availablemeshes, taking into consideration, via three-dimensionalfinite element analysis, the effect of pore size and thick-ness on the mechanical properties of the Ti mesh, as well asvariances in size and anatomical location of bone defects.Clinically, this original effort might eventually translate toshortening the duration of the surgical procedure(s) as wellas minimizing if not alleviating or eliminating the risk ofpostoperative infections, a fine example of multidisciplinaryhealthcare engineering research.

#e paper entitled “Bone Loss around Dental Implants5 Years after Implantation of Biphasic Calcium Phosphate(HAp/βTCP) Granules” by V. Klimecs et al. deals withimplant dentistry as well and addresses the issue of alveolarbone loss around dental implants, clinically, and its impacton dental implant therapy failure. For this purpose, theauthors developed and used combinatorial bioceramicgranules as a filler biomaterial in eighteen patients sufferingperi-implantitis, an infectious disease that causes an in-flammatory process in soft tissues and bone loss around anosseointegrated implant. Clinical evaluation and radiological(3D cone-beam computed tomography) measurements weredone, after a 5-year period, to compare the situation beforeand after treatment of peri-implantitis with the use of dif-ferent bioceramic materials (pure calcium hydroxyapatite vs.combined hydroxyapatite and β-tricalcium phosphate). #isis a registered clinical trial, providing densitometry andmineralization data of bone structures.

On the contrary, S. Wang et al., in the article entitled“Automatic Analysis of Lateral Cephalograms Based onMultiresolution Decision Tree Regression Voting,” de-veloped a fully automatic system to aid in the analysis ofcephalograms, a traditional, conventional, and standardtwo-dimensional radiological X-ray of the craniofacial area(lateral side of the head) often used in orthodontic andorthognathic areas to assess and predict craniofacialgrowth. It is also commonly used for clinical orthodonticdiagnosis and oromaxillofacial treatment planning pur-poses. Lateral cephalograms often require a specialist toanalyze and identify specific landmarks. Herein, a newframework for landmark detection in lateral cephalogramswith low-to-high resolutions is designed. #e algorithmicmethod employs multiscale decision tree regression votingin landmark detection, in each image resolution (low vs.high). Patch feature extraction is based on scale-invariantfeature transform algorithms. Basically, information can beextracted to predict the positions of the anatomicalstructure involving the specific landmarks (45, double thelandmarks often detected by benchmark databases), with adecent average of 72% successful detection rate within aprecision range of 2.0mm. #is is another fine example of“outside-the-box” multidisciplinary and multinationalcollaborative novelty for engineering solutions in health.

Likewise, the paper by D. Xu et al. entitled “InteractiveCompliance Control of a Wrist Rehabilitation Device(WReD) with Enhanced Training Safety” is an inordinateillustration of different disciplines and areas of researchcoming together. It deals with human-robot interactive tasks(and interaction control), robot-assisted rehabilitation so-lutions, and physical therapy, to improve the safety andefficacy of training and compliance adaptation of in-teraction, as are vital for enabling robotic or robot-specificmovements to better suit the varying and/or personalizedrequirements of individual patients. Herein, this workproposes an interactive compliance control scheme on awrist rehabilitation device, with satisfactory trajectorytracking responses. Interestingly, this interactive compliancecontrol method can adaptively adjust the range of trainingmotions and encourage active engagement from human

2 Journal of Healthcare Engineering

users simultaneously, opening doors wide for more clinicalapplications. It is perhaps worth mentioning, for the in-terested reader, that the interactive compliance control of thewrist rehabilitation device was achieved based on an ad-mittance law (where the device deviates from the referencetrajectory in the presence of patient-robot interaction nev-ertheless is also still following the reference trajectory—readarticle for more inspiring details!) due to the availability ofdirect measurement of the interaction torque.

Last but not least, G. P. Panotopoulos et al. revisit thecontroversial issue of cell migration and cell-to-cell com-munications in the article entitled “Non-Motile Single-CellMigration as a Random Walk in Non-Uniformity: #e“Extreme Dumping Limit” for Cell-to-Cell Communica-tions.” Single-cell movement as a random walk in an ex-ternal potential, observed within the extreme dumping limit(defined herein as the extreme nonuniform behavior ob-served for cell responses and cell-to-cell communications), ismathematically modeled in this work. #e authors attemptto solve the Fokker–Planck equation in order to computehigher “moments” of the displacement of the cell and thenbuild experimentally measurable quantities. Seemingly, thedynamics depend, every time, on the external force applied,leading to predictions distinct from standard results of a freeBrownian particle. #is demonstrates that cell migrationviewed as a stochastic process is still compatible with bi-ological and experimental observations without the need torely on more complicated or sophisticated models pre-viously proposed in the literature. #e derived model andequation could be potentially beneficial to explain cellularmigration during relevant biological processes, includingwound healing, inflammation, and embryonic development,via a minimalistic approach.

Finally, while we believe and aspire that this special issuewill be useful and inspiring for scientists, researchers, en-gineers, and clinical practitioners involved in healthcareengineering solutions, it is recommended to pay specialattention to the potentially impactful role of applied bio-dental tissue engineering, drug/gene delivery (controlledand metered systems) and cell therapy, image-guided and-assisted surgery, and nanoDentistry and green dentistry,towards developing better solutions for problems andconditions of the oro-dental and cranio-maxillo-facialcomplex.

Conflicts of Interest

#e guest editorial team declare that they have no conflicts ofinterest regarding the publication of the special issue.

Acknowledgments

#e guest editorial team would like to express gratitude to allthe contributing authors and anonymous reviewers for theirinterest in selecting this special issue as a venue for dis-seminating their scholarly work and for their driven, careful,and insightful reading, appraisal, commentaries, and sug-gestions of the received manuscripts, respectfully. Finally,the lead guest editor is pleased to particularly thank the

BioMAT’X R&D&I Team, Faculty of Dentistry at theUniversidad de los Andes for their technical support (FAI-UANDESINV-IN-2015-101,CONCIYT-FONDEF ID16|10366,and CORFO 18COTE-89695).

Ziyad S. HaidarLucy Di Silvio

Ziad E. F. NoujeimJohn E. Davies

Frederic CuisinierAvijit Banerjee

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