How Artificial Intelligence Could Change the Face of Dentistry

What is Artificial Intelligence?

Artificial intelligence (AI) isn’t a new concept. In fact, it was first mentioned in the 1950s by Minsky and McCarthy, who were considered to be pioneering experts in the field. They referred to AI as a task performed by a machine or programme that, if a human was to carry out exactly the same activity, the person would have to use intelligence to succeed in completing the task. The sorts of tasks could be anything to do with planning, reasoning, the sharing of knowledge and problem-solving.

Since those early days computers have increasingly taken over tasks normally associated with humans. This has enabled industries of all types to manufacture products more efficiently. AI is now so well developed that medicine is using it in a multitude of situations, enabling better outcomes for patients.  When a patient visits an emergency room, diagnosis is faster and more accurate. This means the right treatment is given, which means less delay than might happen if doctors have to discuss a case before deciding on a diagnosis.

AI is also being used to improve communication between medical personnel. In the long run, this all means that by patients getting the right treatment in the fastest time frame reduces time spent in hospital so reducing the stress levels of family and friends.

How the Watson platform uses AI to help the medical profession

The Watson platform was introduced by IBM into medical facilities to assist oncologists to come up with the most appropriate treatment for patients.  All the doctor has to do is input a patient’s diagnosis into Watson which at a touch of a button instantly recommends the best treatment suited to the data it has about the patient. It has already been fed with information provided by medical journals.  With this huge amount of accumulated knowledge, its AI allegedly comes up with the best treatment plan.

AI for dentistry makes its mark

AI is now being used to improve the efficiency of dentistry. Dr. John Kois has developed a similar AI model to IBM’s Watson called Evidentiae. It focuses more on using cloud-based dental software. It concentrates on information processing at the patient level, starting with an online patient history form and all the data relevant to the patient’s treatment.

Evidentiae’s algorithm has been designed to extract data from both medical and dental histories which have been inputted into it and charted examination findings. This enables the technology to generate a full overview of the dental health status of your patient. It has been so well developed that it is able to come up with a valuable diagnosis for periodontal issues and dento-facial alterations. It’s the best AI assistance yet invented for the dental profession.

A few years ago CephX understood the need for artificial intelligence in the dental industry. In response, they created the first cephalometric analysis intelligent algorithm. It enabled orthodontic practitioners to upload their patients’ cephalometric scan and to receive in a matter of seconds a full cephalometric tracing and analysis. This technology improved dramatically the way it was done, because now dentists could instantly receive a full and accurate analysis.

AI and Big Data in Dentistry

With AI and big data making inroads into dentistry soon algorithms will be diagnosing dental problems and the diagnosis will be sent directly to you. This is a step ahead of CephX and cephalometric analysis which is currently helping you with instantly tracing and analysing cephalometric scans. However, it is starting to move quickly as it is developing more intelligent algorithms for the orthodontic industry. One of them is the algorithm that can instantly segment all of your patient’s teeth.

Deep-learning in machine learning is becoming relevant to Dentistry

Advanced technologies that are disrupting all of our lives are also helping to revolutionize dentistry in numerous ways. Deep learning, which is an AI cutting-edge technique in machine learning, is using layered neural networks which are patterned on a human’s brain. Traditionally machine-learning relies on rules that have been handcrafted but defined by experts in human domain but do not improve with bigger datasets. Deep learning has the capacity to create its own unique rules that do improve when more data is added, making it particularly suited at interpreting unstructured data that’s required for more advanced applications like self-driving cars, the prediction of earthquakes, detection of disease and diagnosis and recommendations for treatment in medicine. Dentists do actually have some access to an AI deep learning platform for the detection of cavities today.

AI that can read CT scans for dentistry

Research and development of AI is progressing at such a fast rate that software are already able to read and interpret CT scans and other dental images. In the near future, it will suggest the best diagnosis and treatment which it has gleaned from its ability to review and analyse countless images that have been stored in numerous patients’ databases. What’s particularly important to dentistry is the speed and accuracy that emerges from the use of AI.

The medical profession is presently benefiting a lot from VisualDx, an AI technology that doctors can use to input patient symptoms and any relevant images and within a matter of seconds plausible diagnoses can be retrieved. This AI is soon likely to penetrate the dental industry.

The future of AI in the next decade

In the medical field at least AI is going to become increasingly relevant. This will result in administrative practices being far more streamlined. This, in turn, leads to a reduction in costs. It’s expected that there will be a far higher chance that any unnecessary medical procedures will be avoided, which should heighten patient satisfaction. This is all due to the way information is being inputted and the way humans are communicating with devices.

In the early stages of storing information, a human had to manually enter data. Graphical user interface (GUI) came next, followed by the development of the touch screen and the rapid evolution of mobile devices. All this, coupled with massive improvements in internet connectivity, has brought us to where we are today.

The dentist and a virtual assistant

Human voice recognition is increasingly being used to input information into an AI device. In a decade or so, dentists and others in the medical community will be communicating with AI devices using their own voices. AI will be able to assimilate and analyse data and recommend the best treatment options. This will be happening in the dentist’s chair, where communication with the dentist and the AI device will sound quite natural and not stilted.

It won’t be just a computer standing side by side with the dentist, but a virtual assistant using AI. It will be provided with so much data to analyse that it will come up with just the right treatment in orthodontics and other dental procedures and the future care requirements for the patient, dependent on data that it has been given to analyse. The virtual assistant will be able to make recommendations regarding future care requirements which will depend on the genetic data of the patient.

Summary

In the near future, AI will be able to help the dental practitioner spot a possible tumor, or other irregularities in teeth or gums, through an X-ray or CT scans. Artificial intelligence is already used in some medical centers to improve the efficiency of health care delivery. Software is being further developed to make surgery and imaging test timetabling more efficient by predicting how long each scheduled procedure will take. This and other innovative solutions can easily be adapted for use in a dental practice. CephX’s technologies which are all based on AI are trying to achieve exactly that.

Read more about Cephalometric Analysis
and Digital Dental Imaging Cloud Service

Root Inclination and Today’s Orthodontics

Before orthodontic treatment can begin, it is important to obtain the precise mesiodistal angulation and faciolingual inclination for all teeth being treated. Current technology focuses the most on crown angulation and inclination in general, while the roots do not receive as much attention as they should. Positioning roots correctly is necessary for any orthodontic treatment that is of any use, but because orthodontists tend to focus on the position of the crown, not the root, optimum teeth alignment doesn’t always take place.

The roots are typically overlooked because roots do not directly affect the preferred esthetics of the face that an orthodontic patient is ultimately striving for. Research has indicated that it is still reasonable to suggest that positioning the roots in their right places in the basal bone may reduce the amount of relapse occurring after orthodontic treatment, which is a plus in itself.

Up to now, orthodontists have discovered that problems which occur with crown alignment which have been observed through radiographs are due to incorrect root angulation. It is of utmost importance that these problems are corrected sooner rather than later, as the whole aim of administering orthodontic treatment is to achieve proper and stable teeth positioning. This involves all parts of the tooth, including crowns and roots. However long it takes, patients are looking for a favorable facial appearance as the outcome.

Panoramic x-rays versus cone-beam computed tomography (CBCT) to determine root position

Throughout orthodontic treatment, panoramic x-rays have been used extensively to check root position, even though they are not known for their accuracy. This inaccuracy is allegedly due to distortions found in panoramic radiographs because of non-orthogonal x-ray beams that are directed at the targeted teeth.

Cone-beam computed tomography (CBCT) is a new and more accurate approach for getting images of the position and angulation of the teeth’s roots. They are able to take a 3D image of all the teeth and the roots with minimal exposure to radiation. This breakthrough should be of great interest to the orthodontic community and fulfils the main aim of orthodontic treatment, which is to manipulate misaligned teeth from malocclusion to being more esthetic, so that the complete tooth, crown and root are positioned so as to be both more functional and more esthetic.

A well used way to ensure ideal occlusion is Andrew’s six keys. Four of these keys, namely faciolingual, mesiodistal, occlusal gingival positions and axial rotation, are solely governed by the teeth’s crowns, which are generally relatively easy to monitor clinically. Despite this, crowns do not always indicate accurately enough the complete tooth inclination and angulation.

Mesiodistal angulation and faciolingual inclination can be better established if the orthodontist can get a 3D view throughout the orthodontic treatment process. It is not good enough to depend on imagery found from panoramic radiographs, as the images are often distorted. CBCT provides the accuracy that the orthodontic community really needs to minimize the treatment time of orthodontic teeth alignment solutions.

Why root angulations are important to the orthodontist

Detecting root angulation is important because the optimum position of the roots needs to be achieved so that each root sits independently from others and stands in a parallel position in relation to adjacent roots. It has been found that panoramic x-rays don’t necessarily show the root’s positions with enough accuracy. Some orthodontists notice issues in crown alignment after observing improper root angulations using radiographs. The American Board of Orthodontics issued a recommendation that assessing root angulations should be carried out. This assessment necessitates root parallelism and takes away points if the roots of adjacent teeth are not parallel to one another or make contact with one another. If the angulation of the roots can be detected they can be corrected by the orthodontist.

The process for using CBCT scans and software for detecting tooth angulation/inclination

Accurate diagnostic imaging is important for both orthodontic diagnosis and the planning of treatment. It is also an essential tool that permits the orthodontist to monitor closely the progress of orthodontic treatment. Today, CBCT is more frequently used to provide more complete images of orthodontic patients’ teeth and roots than the use of panoramic images and cephalograms. CBCT scanners have been in use for fifteen years. Orthodontists and dentists can locate inclination/angulation of the teeth using CBCT and compatible software. This is not necessarily a quick process, as it may take some time to locate and segment the roots.

Quality of CBCT scans for root angulation

The orthodontist may see some discrepancies in 3D CBCT images of root positions, but in contrast panoramic radiographs tend to offer false information. This makes 3D CBCT scans far more reliable than anything that has come before it to detect root angulation as well as images of the teeth and crowns.

Coming soon for orthodontists

At CephX, our aim is to help orthodontic practitioners globally to save valuable time by offering accurate dental imagery analyses. We offer an instant service which is made up of the highest quality cephalometric analysis that helps to improve productivity and efficiency in your practice. Currently, we provide a cephalometric analysis service for 2D cephalometric x-rays. The dental practitioner uploads the patient’s cephalometric x-ray scan, and within a matter of seconds he or she will receive the full cephalometric analysis. There are 2 more services we will be adding soon which offer automatic and instant results too. These are:

  1. A cephalometric analysis service for 3D cephalometric scans using CBCT.
  2. Teeth segmentation, including Root Recognition which provides information about every tooth, root direction, impacted tooth position and supernumeraries, using CBCT.
Read more about The History of Orthodontics
and Ricketts Cephalometric Analysis

The Importance of Precise 3D Localization of Impacted Teeth Using CBCT in Orthodontics

An impacted tooth, i.e. a tooth which hasn’t completely erupted, is unlikely to do so because of its position in relation to adjacent teeth and nearby bone or soft tissue. Impacted teeth are most commonly the mandibular 3rd permanent molar, the maxillary permanent canine or, on occasions, the premolars. The impaction could be vertical, horizontal, mesioangular, distoangular and sometimes inverted, which is actually a rare occurrence. Inversion is quite extreme, as in this case the tooth has reversed its position and is upside down. In order for orthodontists or dentists to correctly treat this condition they need to be able to localize it precisely to make a treatment program easier to implement.

The cause of impacted teeth

Typically, a tooth becomes impacted when the patient’s mouth does not have sufficient space for it. The most likely teeth to become impacted are the wisdom teeth. Because they are the last to erupt, the jaw and mouth may have stopped growing, leaving no space for these newly erupting teeth. Maxillary canines, or cuspids, may also become impacted.

When the canine teeth are impacted, you may use eruption aids, such as braces to encourage the impacted teeth to erupt. If you are unable to get the impacted tooth to erupt it may need to be extracted and a dental bridge or implant can then be fitted into the space. Accurate imaging techniques are vital to determining possible treatment options.

When dentists and orthodontists need to localize impacted teeth

It’s difficult to see the topography of both the impacted tooth and the area around it without using a reliable imaging diagnostic tool. Up to now, before treatment could take place, 2D imaging techniques have typically been used to get dental imagery in order to make an accurate diagnosis and for localizing the non-erupted teeth so that treatment can be planned. More recently, it has been discovered that 2D radiography has not been sufficient to determine the precise location of the problem, including what the impact is on adjacent teeth, and the structure of the affected tooth’s roots, which is key to starting any type of useful treatment.

The cephalogram, or ceph, has been in use by orthodontists as the usual method of getting dental imagery for analyzing the dental, skeletal and soft tissue relationships in patients for a number of years. 2D, or direct cephalometric x-ray technology, has been used successfully for many decades by orthodontists. Currently, orthodontists still use this method, although some dental clinics have begun to use 3D cephalometric analysis as an addition. If a patient is seeking to get teeth straightened through the use of braces treatment or aligners, the better the analysis of the patient’s teeth, the better the subsequent treatment program initiated.

The most recent diagnostic tools used by dentists and orthodontists

At the forefront of diagnostic tools, as well as computed tomography (CT) and 3D tools, is cone-beam computed tomography (CBCT), which has been shown to produce high-quality 3D images that provide an accurate diagnosis with a minimum amount of distortion. The cost factor is important, but this technique compares favorably with others and it clearly reduces radiation exposure to much lower levels than other CT technology. CBCT has shown its capability to improve diagnosis and its contribution to modifying treatment planning for impacted teeth. CBCT has shown it can more accurately localize a tooth, evaluate its position in relation to other teeth, assess the follicle size and analyze resorption of any adjacent teeth. A dentist working alone needs to annotate teeth, including impacted teeth, which can be hard work because imaging software is used which is then interpreted manually.

Studies have indicated that CBCT provides much more information than other methods for localizing impacted teeth, root resorption, cleft palate and 3rd molar assessments. CBCT also provides better images of roots, so it’s a valuable tool for the assessment of pre-orthodontic or post-orthodontic root re-sorption. It has also been shown to be the best option for determining the angulations of roots.

The increase in availability of CBCT technology has meant that the greater use of it has led to further development of the technique by dentists and orthodontists leading to better treatment outcomes for patients. As far as impacted teeth are concerned, images obtained through CBCT are able to accurately determine their angulation and buccal-palatal location. It is also able to pinpoint the exact location of impacted teeth in relation to adjacent teeth’s roots as well as the extent of resorption.

Being able to get an accurate view of these features is important in planning appropriate treatment to move the impacted tooth in the arch and lower the risk of root resorption taking place in adjacent teeth. Different kinds of imaging software permit CBCT image reconstruction in several planes, which offers a more precise view of the position of the impacted tooth.

When CBCT should be used

Cone-beam computed tomography (CBCT) has taken over more recently as an important method of collecting 3D volumetric data. However, it is typically considered that it should only be used in certain cases when more conventional radiography is unable to provide adequate diagnostic information. The sort of specific situations include those patients who suffer from a cleft palate, assessing the position of an un-erupted tooth, a supernumerary tooth, identifying root resorption and planning orthognathic surgery.

2D diagnostic imaging, like traditional radiographs, cephs, photos and videos, has been used routinely to provide orthodontic diagnosis for many years, but not with complete accuracy. The limitation of this type of imaging has been overcome by CBCT and is likely to be used more often in the future. It’s a useful diagnostic tool for planning braces and aligner treatment as it gives a better overall image of the structure of the teeth.

Artificial intelligence in the dental world

As more and more devices are used to assess the status of teeth, so Artificial Intelligence (AI) and machine learning are starting to dominate all areas of life. AI is revolutionizing the transforming of unstructured data into useful information which is likely to become just as relevant to the dental industry. AI provides an end to end solution which in the end will provide better outcome for patients.

At CephX, we help orthodontic practitioners throughout the world save valuable time by providing accurate dental imagery analyses and interpretations. We offer an immediate service which is the highest quality cephalometric analysis that improves your practice productivity and efficiency.

Currently, we offer 2D x-ray analysis only, but soon we are opening our doors to 3D analyses, as well as immediate and accurate 3D teeth annotation, including the localization of impacted teeth.

Read more about Are Clear Aligners Right for Your Patient?
and Case study – using CephX in full time orthodontics office

Comparison between 2D and 3D Cephalometric Analyses

The cephalogram has been in use by orthodontists as a standard method for assessing the dental, soft tissue and skeletal relationships in patients for some time. 2D or direct cephalometric x-rayanalysis has been used successfully now for over 70 years in orthodontic practices. Currently, its status amongst orthodontists is stable although dental clinics start to use 3D cephalometric analysis as well.

Despite the fact the use of 3D X-rays are becoming more a part of dental practices, this doesn’t mean there is no meaningful role for 2D imaging still has a rightful place, that doesn’t suffer as much from the effects of radiation exposure.

Cephalometric radiography has developed as a key orthodontic diagnostic tool and before craniomaxillofacial surgery is considered. Typically, cephalometric factors are measured by using the two-dimensional cephalometric analysis on either lateral or frontal analysis. More recent studies have shown that 3D imaging presents greater reliability.

This 2D approachprovides a 2D view of what is unarguably a 3D object. The 3D technology is increasingly being accessed and assessed for optimal orthodontic treatment and results, but cephalometric x-raysare still the most common x-ray cephalometric analyses which in use by orthodontists. The 2D method does provide sufficient information which enables the orthodontist to make good judgments regarding the most suitable orthodontic treatment. In the not too distant future 3D cephalometric analysis are likely to be introduced more into orthodontic practices.

How a cephalometric scan is used

The process when doing a 3D cephalometric scan is a bit different when doing a 2D cephalometric scan. The 2D ceph is taken on the side of the patient’s head, while a CBCT scan takes place when the C-arm or gantry rotates 360 degrees around the head capturing multiple images in the process from a number of different angles which are then reconstructed to form a single 3D image.

After the ceph analysis is ready, the orthodontist can then make good decisions about treatment options for the patient. The 3D technique enables the orthodontist to calculate how certain orthodontic treatments will affect the patient’s jaw and the bone surrounding it. It also gives an idea of the growth tendency of the teeth and jaw. This information, if required, may also be used to decide on a course of treatment.

Similarities between 2D and 3D cephalometric x-rays

Cone-beam computed tomography (CBCT) enables the orthodontist to get craniofacial measurements in 3D with good geometric accuracy. CBCT is also starting to target 3D cephalometric analysis. The one problem detected is the amount of radiation exposure that CBCT causes which is relatively higher when compared to more conventional radiographs. This is no doubt one of the constraints that will need to be addressed so many orthodontists restrict its use to high priority patients who need a detailed diagnosis.

One of the attributes of this technology for the orthodontist is the increase in diagnostic accuracy compared to 2D x-rays, particularly when identifying orthodontic conditions such as overlaid teeth, hidden nerve channels, impacted teeth, airways analyses and concealed roots or anomalies in the temporomandibular joint. 3D cephalometric x-rays are no doubt a useful advancement in technology but there are some features they share with 2D. The 3D cephalometric x-rays has higher exposure to radiation, but their images come in high resolution so they are clear to view.

When trying to locate an incisor tooth on a cephalogram when a patient is suffering from crowding of the anterior teeth these featurescan be located quite easily using the 3D method. It is also able to reduce the mistakes of identification and projection that lead to errors in cephalometric measurement.

Immediate cephalometric analyses provided by CephX

At CephX, we help orthodontic practitioners around the globe to save precious time and to receive an immediate and high-quality cephalometric analysis they now expect. Currently our service available on the basis of 2D x-rays only. We are determined to keep up with cephalometric analysis trends so we can meet the needs of our orthodontists who are starting to use 3D scanners more and more.

Once this feature will beready, you can expect the same cutting-edge service as you have been receiving from us up to now.

Read more about Top Dental Products for 2015
and Case study – Dr. Ivan Goryalov

The History of Orthodontics

Have you ever wondered or had a patient ask you how orthodontics came to be? Maybe you read through the history of early orthodontists at one point in your career or have always had a personal curiosity about how things like the shape of brackets or the metal used in archwires came to be (did you know that one of the first archwires was actually a piano string?).

Although the most significant changes in orthodontia came in the last 200 years, there are actually over 2,000 years’ worth of history supporting the concern that people and medical providers had for tooth malocclusion.

According to the British Orthodontic Society, both Hippocrates and Aristotle (famous Greek physician and philosophers, respectively) described the problems of malocclusion as early as 400 and 350BC. Medical writers a few years later began recommending “treatments” like applying finger pressure or filing down the irregular teeth to address issues such as a lack of space.

The First Orthodontic Device

It wasn’t until the 16th century that human anatomy and medical interests sparked an advancement of knowledge in the treatment of dentofacial problems. By 1728, a French dentist by the name of Pierre Fauchard developed a device used to expand the arches when severe crowding was a concern. The appliance was made from a metallic band that was tied onto the teeth by waxed, silk ligatures. And in 1750, John Hunter is documented to be the first dentist to use a fully metal arch with metal ligatures.

Gradually, other dental practitioners experimented with preventative treatments, extractions of deciduous teeth, and using bite blocks with chin caps to address crossbites.

By the mid 1800s, dentists began understanding how the anatomy and placement of specific teeth played into alignment of the bite, combined with genetic factors and issues such as nursing difficulties during infancy. Types of occlusion were outlined to describe the variations of malocclusion and tooth placement around this time.

But Europeans aren’t the only ones to have incorporated orthodontic techniques or a concern about malocclusion. It turns out that Egyptian mummies have also been found with metal bands around their teeth, implying to archaeologists that an attempt was made to move them while still alive.

Modern Orthodontic Appliances

The first dentist to use screws and elastic bands to rotate teeth was J. M. Alexis Change. Although considered to be the first to use a long-term retention method after treatment, he is especially noted for completing cases in as rapidly as only three months. (Unfortunately, the remodeling process of alveolar bone wasn’t understood until the late 1850s.)

The 1800s held the most significant growth and discovery of orthodontic possibilities and treatment methods. By 1900, Edward H. Angle declared orthodontics as the very first dental specialty. In 1907, the European Orthodontic Society was founded and in 1926 the first international orthodontic conference was hosted in New York. By the 1960s and 70s, specialized programs and post-graduate training for dentists became standard.

Cephalometrics began to take on a special role in early orthodontics as dentists started to understand the role that teeth played in facial bones and soft tissues. CBCT technology made craniofacial anatomy and tooth positioning easier to assess prior to treatment, allowing orthodontists to opt for plans that would consider specific skeletal abnormalities or surgical procedures as necessary (both for functional and aesthetic purposes.)

Until the 1970s, modern orthodontists attached brackets to metallic bands that wrapped around the teeth. As new materials such as stainless steel began to be incorporated, lingual braces were also introduced.

The Shift from Metal to “Clear” Materials

The early 1980s brought about the invention of the initial type of “clear” or “tooth colored” braces, as ceramic appliances first became available. Some dentists even experimented with removable plastic trays as early as the 1940s. But it wasn’t until 1997 when 3D computer imaging (CAD/CAM) technology made it possible for orthodontic appliances to be crafted in a series of accurately designed removable trays. Invisalign, as it was called, first became available to patients in 2000.

Today, dozens of clear alignment and ceramic orthodontic brands exist. That’s not to mention the other modifications that have been developed over time, such as trap-door systems and changes in the types of metals used for their specific properties.

Although clear aligners were originally most effective for patients who had experienced orthodontic relapse or only faced minor tooth misalignment issues, today’s digital accuracy and treatment planning makes it possible for orthodontists and dentists worldwide to correct a variety of malocclusion and bite cases, including those more moderate to severe.

Digital dentistry and cloud-based treatment planning allows dentists to incorporate the skills of experienced 3rd party practitioners in off-site labs and thus build on the quality of care and types of services available to their patients. As a result, general dentists are also capable of providing limited orthodontics, comprehensive tooth alignment, and even accelerated short term cosmetic braces within their private practices.

Technology that Revolutionizes Orthodontics Around the Globe

As an independent imaging resource, CephX is able to work with a wide variety of the world’s leading orthodontic manufacturers and practitioners to provide cephalometric analysis to provides around the globe.

Do orthodontic scans, CBCT images, X-rays, and other intraoral imaging steps keep your practice from running as efficiently as you would like? Because CephX is fluid with other leading orthodontic support services, we’re able to help you take your dental business above and beyond your current capabilities without the headache of worrying about whether or not your software or imaging tools can integrate with one another.

Thanks to online tracing and automated analysis, CephX clients can access accurate and reliable treatment planning support for their orthodontic patients.

About CephX

At CephX, we provide professionally evaluated orthodontic imaging services to dentists and orthodontists around the globe. Your images are instantly transferred to a secure cloud-based system allowing professionals to resource the support and planning from peers in the field. Not only does this resource improve the quality of care and treatment planning for your existing dental patients, but it boosts the efficiency of your practice and limits out-of-office referrals.

To learn more about CephX, request a free consultation!

Read more about How to Improve your Dental Practice
and Digital Dentistry: How it Increases Patient Quality of Care