Cone Beam Computed Tomography: The Future of Digital Dentistry


On the forefront of dentistry, a new type of CT scan View definition in a new window is becoming the norm. The CBCT, or Cone Beam Computed Tomography, is a CAT scan that offers a three-dimensional view of the patient’s cranial facial structure. These 3D images provide more accurate diagnoses, and allow for better and more efficient treatments. The CBCT is a more advanced and efficient way to obtain the diagnosis View definition in a new window that minimizes radiation exposure. The precision diagnosis obtained by the CBCT can be utilized in all branches of dentistry, including:

1. Orthodontics

Benefits to orthodontic View definition in a new window imaging include the ability to analyze skeletal symmetry, assess joints and occlusion View definition in a new window, plan surgical treatments, as well as assess growth potential in younger patients.

2. Endodontics View definition in a new window

Endodontically, the CBCT allows the dentist to diagnose endodontic pathosis and evaluate root fractures and trauma. The accurate information facilitates the precision of the treatment. The anatomy of the dental root structure is complex and three dimensional.  A 3D image will provide the most accurate assessment. This will increase the success rate of root canal treatment.

3. Implantology

Accessible 3D images allow bone quality and quantity to be assessed, as well as the anatomical nerve structure.  With this information, a surgical guide can be created to ensure dental implant View definition in a new window placement can be done precisely and safely.

4. Oral Surgery

The side effect of the numb jaw associated with wisdom teeth extraction is often feared by patients. With this new technology, a safer and smarter protocol can be established before surgical procedures.  The CBCT data allows surgeons to precisely assess the vital anatomical structures. So, surgical protocol can be safely carried out to avoid complications and side effects for impacted tooth extractions, cyst removals, and other surgeries.

5. Periodontics

With regards to periodontics, the CBCT can evaluate bone anatomy and proximity to pertinent anatomical areas to better assess the source of the infection or lesion and treat it more precisely.

6.Orthognathic Surgery

Orthognathic surgery is often combined with orthodontic treatment. It improves jaw size, corrects jaw position, and, in some situations, opens the airway by moving the recessed jaw forward. The CBCT allows for an accurate assessment of the anatomical structures and landmarks, and to plan surgery with safe and precise protocol.

7. Upper Airway Assessment

The 3D image of the cranial facial structure allows us to assess the oral and nasal tracts better than ever before. Any sinus or nasal blockage can be viewed precisely to aid an EMT to carry out more accurate treatment.

Oral-pharynx restrictions are associated with sleep apnea. Beyond the conventional medical treatments, dentists can also provide oral appliances or remodel the oral cavity View definition in a new window through orthodontics or orthognathic surgery to clear the air pathway.

The Future of Dentistry

Along with the CBCT, there is now digital imaging software that allows for the integration of such scans into a comprehensive treatment outline. Assimilating the 2D and 3D scans allows for a custom treatment protocol to be created. The combination allows for a full integration of the CBCT file, granting the ability to perfectly fabricate the patient’s dental structure. The rich information taken from the CBCT can be incorporated with CAD/CAM technology to mill or 3D print entail restorations and appliances.


What Makes a Perfect Smile?

A perfect smile is healthy, confident, and happy. If you are uncomfortable, unhappy, or unconfident it reflects in your smile. Is feeling uncomfortable or unconfident about your mouth keeping you from smiling? Your dentist can be your partner to remodel your mouth, and help you unlock that perfect smile inside of you.

There are more components to a healthy smile than just a set of pearly white teeth. The foundation begins with the jaws. When the jaws are properly developed and in the correct position, they provide the proper framework needed for a beautiful smile. Healthy gums act as a frame and a support element to your teeth as well. Lastly, the proper alignment and appearance of your teeth can make your smile sparkle.

The Elements of a Beautiful Smile

In the past three decades, dentistry has been focused on smile creation. There are certain components that dentists use for smile design. While there are many different principles of smile design, here is an overview of a few major elements:


Oral hygiene is the absolutely essential to keep a healthy and beautiful smile. Poor habits and diet can discolor and stain your pearly whites. The color of the smile, however, can be altered through cosmetic procedures such as bleaching View definition in a new window, bonding View definition in a new window, or veneers View definition in a new window.

The color of your gums is also important. Healthy gums have a firm texture and a pale pink coloring. Inflamed gums are red and swollen. Inflammation can be associated with diet, environment, medication, mouth breathing, poor oral hygiene habits, or physical health. Regular dental visits with your hygienist can help to maintain healthy gums in addition to following good daily oral hygiene habits. Depigmentation is available through lasers for dark and discolored gums associated with smoking.


smile design blog diagram

The dynamic curvature of the lower lip line while smiling acts as the frame of reference. When it is in harmony with the incisal edges, it will be more aesthetically pleasing.

Incisal Edge

The incisal edges are the bottom line of your top row of teeth. The incisal edge can be recreated or rearranged through cosmetic dentistry to create a more pleasing smile line View definition in a new window.

Relative Tooth Dimension

The relative tooth dimension is based off of The Golden Ratio that exists in nature. Cosmetic dentistry gives us the opportunity to utilize the Golden Ratio to recreate pleasing proportions in your smile. There are two components to how we use this ratio in smile design. When looking at an individual tooth itself, ideally it is about 75% as wide as it is long. When looking at your teeth together, the width of your lateral incisor is also 75% of the width of your central incisors. In other words, your central incisor is ideally 1.618 (the Golden Ratio) the size of your lateral incisor.

golden ratio

Axial Line

The axial line is the center line of the tooth. This line shows how each tooth is inclined towards the midline of your face. When each tooth’s axial line is properly angled toward the midline it will appear more pleasing.

 Zenith of Gingival Contour

Zenith is the highest point of the dental axial line in relation to the gums. It is slightly off from the center of each tooth which is important to recreate a natural look during laser gum contouring. Cosmetic dentists apply this principle when making teeth longer or making a smile less gummy.

The Bottom Line on Smile Design

The bottom line is this: these smile design elements are tools, not absolute rules. The goal of smile design is to elevate and emphasis your own beautiful, natural smile. Just as every person is different, every smile is different. The best dentists acknowledge this and implement smile design to help create the perfect smile for you.



What Is OMT?

If you suffer from open bite, teeth going crooked again after braces, trouble sleeping, speech problems, grinding teeth—OMT can help. But what is OMT? Orofacial myofunctional therapy (OMT) is a series of exercises designed to counteract dysfunctional muscular habits that can contribute to these oral health problems. OMT exercises aids in the proper development of the teeth, jaws, and musculature in order to achieve craniofacial homeostasis.

OMT Creates Good Habits

Imagine a basketball player practicing jump shots in a gym, or a pianist perfecting a new piece of music. We all understand that practice makes perfect. The repetition of any action establishes neuromuscular pathways. Orofacial myofunctional therapy trains you in a similar way. OMT is a conscious effort that becomes a subconscious habit through repetition.

Exercising the Tongue

The tongue is an integral part of orofacial development—whether it is resting properly on the roof of the mouth, or dynamically aiding in the process of swallowing. The tongue presses food upwards and forwards against the roof of your mouth (the hard palate) to lead it to the throat. When the tongue is properly manipulating and guiding food in the swallowing process, the directional movement stimulates facial bone growth.

The base of the tongue is connected to the hyoid bone— the only floating bone in the body. The hyoid bone is connected to multiple muscles and ligaments that control the head, throat, and shoulders. So when the tongue is operating correctly it provides stimulation to establish the proper tonicity for the rest of those muscles. This creates balance in the body. It aids in keeping an open airway when you sleep, and encourages proper posture while you sit and stand.

OMT exercises reinforce proper muscular posture and movement. Take this exercise for example:


The Ping-Pong Press exercise consists of pushing your tongue against your fingers through the cheek. By repeating this in sets of 30, it builds tongue strength through resistance over time.

OMT exercises are designed to build off one another. As you go through an OMT program, you can properly aid jaw bone development supporting and maintaining proper craniofacial balance and posture. Craniofacial homeostasis eliminates unnecessary cervical tension. Not correcting bad habits can increase the chance of orthodontic View definition in a new window relapse with a low tongue posture or thrusting, and can obstruct your airway by the tongue falling back to the throat due to weaker muscular.

The Benefits of OMT

Now that you know the answer to ‘What is OMT?’ you can better understand the specific benefits of Orofacial myofunctional therapy. Check out Tooth Mingle’s previous post to learn about six benefits of OMT.


6 Benefits of OMT

Proper posture is important for a healthy body. Posture, however, is more than just sitting up straight at the dinner table—oral posture can be just as important to your overall health. OMT, or Oral Myofunctional Therapy, is a series of exercises to re-pattern and optimize oral and facial functions. It trains you to have healthy oral posture. OMT provides many other benefits as well. Here are six of them:

1 . Cuts out Bad Habits

line through open teethWhile sucking thumbs and biting on pens may seem small, their impact can be huge. These bad habits promote an incorrect alignment of teeth and jaw leading to the need for braces, surgery, or orthodontic View definition in a new window relapse. OMT encourages healthy habits that help teeth grow in straight and stay straight.

  1. Keeps Lips Sealedlip seal

A proper lip seal is an indication of healthy nasal breathing. Nasal breathing is the natural way to take in air. The nose filters, humidifies, and adjusts the temperature of the air. A lip seal is part of a proper oral posture that is important for ideal jaw and bone development.

  1. Eliminates Mouth Breathingline through dynamite

Mouth breathing increases the inflammation of the mouth and the upper respiratory tract leading to gingivitis View definition in a new window, sore throat, cold, and ear infection. Inflamed soft tissue will obstruct the air pathway and can result in sleep apnea. Mouth breathing also leads to poor oral posture. It leads to a head forward posture that creates cervical tension.

  1. Improves Chewing and Swallowingimgres

The tongue guides food in the chewing and swallowing process. When working properly, the tongue presses food upwards and forwards against the hard palate to lead it to the throat. The tongue’s repeated dynamic movement aids in the development of the upper jaw. Without proper directional stimulation from the tongue, there could be insufficient facial bone growth and crowding of the teeth.

  1. Promotes Proper Functional Spacefunctional space-OMT

OMT promotes the proper functional space. This means the growth of oral-facial structure can develop correctly in three dimensions—the height, width, and depth of the oral cavity View definition in a new window. Proper functional space encourages healthy development of the jaw, alignment of the teeth, position of the jaw joints, and prevents the tongue from obstructing your airway as in sleep apnea.

  1. Promotes Oral-Facial Growth

oral facial growthOMT trains your mouth to habitually stay in the proper posture to promote growth. That means the tongue is functioning and resting on the hard palate. If the tongue stays too low, it could lead to an insufficiently developed jaw causing teeth to grow in crooked.

Healthy oral posture encourages a well-developed and symmetrical face. OMT can redirect growth and minimize asymmetry in facial structure. Beauty is truly beyond skin deep—your natural genetic expression could be enhanced by OMT.

OMT is a method to improve oral health problems. If we look at the causes of these unhealthy problems, we might be able to prevent them from developing in the first place. This starts with healthy breathing through the nose.  By decreasing allergens and toxins in the air you breathe and the food you eat, you can have a better start to oral and general health.



Is Wearing Your Retainer A Necessity?

holding retainerRetainers help maintain the results of orthodontic View definition in a new window work. People think that once they are done with their braces, they get to keep their straight teeth forever. But that’s not a reality. They either have to wear their retainer View definition in a new window as told, or risk the chance that their teeth will shift. We all know someone whose dog ate their retainer. They are hard to keep track of and annoying to handle. The question still remains: Can orthodontic treatment be lasting if a retainer isn’t worn?

The answer is yes. However, it’s highly dependent on three major factors.

1) Proper Tongue Posture and Swallow

Healthy tongue posture is when the tongue is resting above the dental space on the palate, which should happen naturally throughout the day and night. A healthy swallowing pattern includes the tongue hugging the roof of the mouth, then pressing back to push the food down. This dynamic tongue movement against the palate will also assist with jaw development, making it very important. However, if the tongue sits lower in the dental space, the alignment of the teeth might be negatively impacted.

2) Nasal Breathing

Natural and healthy breathing is breathing through the nose. There is a physiologically intended need for air to be filtered, humidified and temperature adjusted for us to take in essential oxygen. Research also indicates the benefits of nasal breathing include nitric oxide production, known for its bactericidal and vasodilation properties. Also, air flow in the nasal cavities has a positive influence on the growth of the upper jaw bone. If we breathe through the mouth due to a stuffy nose, besides causing an inflammatory of the oral and pharyngeal soft tissues, it will also cause tongue posture to drop and stay within the dental space, which will negatively influence the alignment of the teeth.

3) Lip Seal

Healthy lip seal posture is one where both the lips are effortlessly pressed together without muscle strain, which can only be achieved when a person breathes through their nose and maintains proper upright tongue, cervical spine, and body posture.

If all three components are obtained: Proper tongue posture and swallow, nasal breathing, and lip seal, a state of homeostasis has been achieved. If homeostasis can be maintained in the body, the position of beautifully aligned teeth should stay straight. Any undesired movement of the teeth is an indication of a compromised physiological condition, which intervention calls for.


Happy New Year!

Welcome to the new year 2011! January is the time for new years resolutions – making goals to improve life and health. Eating healthy, hitting the gym or reading more books are popular ones, but it’s time to take a fresh look at your oral health!

This year, make a proactive change to your oral health. It is important to realize that the longer a person waits to take care of dental treatment, the worse a problem can become! Missing teeth, chipped or broken restorations, bruxism View definition in a new window or jaw soreness are all conditions which can affect your bodily health in a serious way if not treated right away. The connection between the mouth and the rest of the body is significant. Do not procrastinate – it is in your best interest this year to see your dental professional before things get worse.

Hygiene is also important. A clean mouth is not just pretty for your social life and professional appearance, but important for your bodily health! Those who want to improve the health of mouth and body should consider the simple act of regularly brushing and flossing their teeth! Tartar can be tricky to remove without professional help, so the best defense is proactive care. This is why regular cleanings with your dental professional are so important. The American Dental Association (ADA) has stressed the importance of maintaining good dental health for adults and children of all ages, not just for healthy gums and teeth, but to ensure good overall health.

Family values are important – brushing and flossing can be an important part of those values! Parents should use the new year to educate their children on the importance of brushing their teeth. If children are taught about dental care, statistics show they are more likely to continue caring for their teeth and gums in adulthood. One important tip from the ADA regarding teeth cleaning is to floss first before brushing because there is more of a chance for the fluoride View definition in a new window from the toothpaste to get between the teeth.

Be healthy and safe this new year; may 2011 be a year for health!


Does Your Dog Snore?

Believe it or not – dogs really do snore! It’s an unfortunate trait, but the relatively thick / short necks and large tongues of certain breeds (like pit bulls) usually mean excess soft tissue. Lost muscle tone decreases the flow of air, causing an obstruction in which the collapsed airway will vibrate. This results in the snores you’ve come to hate (or tolerate), especially if your dog sleeps in your bed!

Humans and dogs snore for the same reasons – something is blocking their upper airway, due to either a “fat” neck or extra tissue blocking the airway while reclining or laying down. If your dog has consistent loud snoring, or gasps for breath, schedule an appointment with his veterinarian. The following are some of the top associations with snoring:

  • Being Overweight: Does your dog have a definable, slim waist? If not, and your dog looks pudgy around the middle, he is most likely overweight. Extra tissue and flabby tissue can push the upper airways closed. Consider using a diet dog food, feeding her less and frequent exercises like jogging or the dog park.
  • A Large Neck: If your dog has a large neck (in relation to its head), like a pug or a pit bull, the dog’s airway may be at risk. Similarly, in humans, a woman with a neck larger than 15″ in circumference (or a man with a 17″ or larger neck) may be associated with snoring.
  • Sinus Congestion: Does your dog have any kind of cold, allergies or nasal discharge? When the nasal passage is blocked and breathing takes place through the mouth, positive air pressure decreases in the throat, causing the airway to collapse, causing snoring.
  • Pain Medication or Tranquilizers: Just as taking muscle relaxants can cause snoring in humans, pain reduction medication will relax your dog’s muscles to the point that they can cause the airway to collapse, causing snoring.
  • Having a Flat Face: That cuteness comes with a price. Breeds like Pekinese, Pugs and Boston Terriers often have more nasal infections and easier blocked airways than longer nosed breeds. Consequentially, they almost always snore.
  • Smokers: Fictitious dogs love playing poker, but in reality, dogs do not smoke. Humans do. Inflammatory reactions can be caused by smoke irritation, when tissue becomes swollen, blocking the airway which causes snoring. Place his kennel in a clean-air space, and don’t smoke near him.

Creating A Mona Lisa Smile

When you think of fine art and priceless paintings, Leonardo da Vinci no doubt comes to mind. It may be a surprise to learn, however, that the same technique Leonardo used to create lifelike works of art is the same technique a master dentist professional uses for reproducing a beautiful “Mona Lisa Smile.”   Leonardo’s layering technique used to achieve the Mona Lisa‘s alluring, dreamlike quality is identical to the method that a true artistic ceramist will utilize to create lifelike dental restorations.

The cabalistically alluring smile of lady Mona Lisa remains a mystery, but French scientists say they have cracked a few secrets of the famous painting. Researchers at The Louvre have studied seven of the museum’s Leonardo da Vinci paintings, including the Mona Lisa, to analyze the master’s use of successive ultrathin layers of paint and glaze – a technique that gave his works their soft and sensual quality.

Specialists from the Center for Research and Restoration of the Museums of France found that da Vinci painted up to 30 layers of paint and glaze on his works to achieve astonishingly high levels of subtlety. Added up, all the layers are less than 40 micrometers, or about half the thickness of a human hair, researcher Philippe Walter said Friday. The technique is called “sfumato,” and it allowed da Vinci to give outlines and contours a hazy quality (creating an illusion of depth and shadow). The technique’s use is well-known, but scientific study on it has been limited because, until the advent of advanced laser technology, tests required actual samples from the paintings.

Just as Leonardo da Vinci used the sfumato technique to intricately layer paint and glaze (creating beautiful works of art), a master artist uses similar techniques of layering porcelain powder to create realistic dental restorations. Dr. Sun chooses from approximately 30 different shades of porcelain powder, which are layered to create the illusion of a natural tooth. The result is an extremely high quality restoration, indistinguishable from an organically created tooth. It is important to note that the vast majority of porcelain technicians use only a few rudimentary shades of porcelain powder, resulting in a mediocre restoration which may look slightly artificial.

When searching for a cosmetic dentist, look for samples of his or her team’s work! Cosmetic dentists rely on an integrated team of clinical and laboratory experts to assist in creating lifelike porcelain restorations. Realistic shade and color should be present, not one solid shade of white. If possible, see how the restoration illuminates (how the tooth looks in natural sunlight) – is there a shift, like a natural tooth? Find a master artist who can provide you with the smile of your dreams. If you need a resource to find a cosmetic dentist in your area, the American Academy for Cosmetic Dentistry provides a search tool to find accredited AACD cosmetic dentists in your area.


Stop Snoring!

Snoring is common – most people snore occasionally – but is not a welcomed physical phenomenon. Snoring is noisy, disturbing, can affect the quality of your sleep and prevents your bedroom partner from having a peaceful night! So what are the causes and treatments of snoring? Technically speaking, snoring is defined as the vibration of respiratory structures and the resulting sound, due to obstructed air movement during breathing while sleeping. In some cases the sound may be soft, but in most cases, rather unpleasant.

Generally speaking, the structures involved during vibration (creating subsequent noise) are the uvula and soft palate; the irregular airflow can be caused by any part of airway. Blockage of these passages can be due to inflamed, enlarged glands or ‘floppy’ soft tissues, a large or set back tongue, a small or receded lower jaw or an obstruction of the nasal passageway. These physical attributes can be hereditary or from environmental influences like smoking, alcohol, medications, allergy, asthma and upper respiratory infection.

Snoring can also be a symptom of sleep apnea, an unhealthy condition. While snoring is caused by a narrow airway, sleep apnea is a true breathing obstruction, which awakens the sleeper to begin breathing again. It can occur frequently and can lead to sleep deprivation with further health repercussions. Snoring is a common symptom of sleep apnea, but snoring by itself does not involve the cessation of breathing.

Besides diagnosing what causes snoring,  non-invasive and self-regulatory approaches to control snoring can be a good start: losing weight (decreasing fatty tissues which restrict the airway), sleeping with one’s head elevated and sleeping on one’s side (preventing the gravitational collapse of the airway), limiting alcohol consumption, smoking and medication intake (to prevent dilated, dehydrated, inflamed or floppy tissues), and clearing of the nasal passage (a stuffy nose can make inhalation difficult, creating a vacuum in your throat drawing movements the soft tissues). Nasal decongestants or nasal strips can also be effective in opening up the nasal passage; when combined with a snore guard under a health professional’s care, this can be very effective in treating mild to moderate snoring.

There are several designs of snore guards to aid in suppressing snoring, from a simple diagnostic bite plate to a fixed or adjustable double jaw device which repositions your lower jaw and/or tongue forward and downward (opening the airway at your throat). Ask your dentist whether he or she can help you with fitting a snore guard.If you suffer from severe snoring combined with sleep apnea, a continuous positive airway pressure (CPAP) machine is often used.

In most severe cases, a surgical approach might be advised. Surgical treatments like UPPP (Uvulopalatopharyngoplaty) and TAP (Thermal Ablation Palatoplasty) can relieve physical blockages to the breathing pathway. A pillar procedure (palatal implantation) can stiffen and cease vibration of the soft palate to stop snoring.

One solution that might surprise you? Sing and playing musical instruments  that tone up your throat muscle and soft tissues of one’s airway can help. Even playing the didgeridoo may help snorers! A 2005 study in the British Medical Journal found that learning and practicing the didgeridoo helped reduce snoring and sleep apnea (!) as well as daytime sleepiness. This appears to work by strengthening throat muscles , thus reducing their tendency to collapse during sleep.

At last, I wish everyone a quiet, peaceful and healthy night’s sleep every night – be well rested and ready to carry on a productive and happy tomorrow!


What Can Be Done For Sleep Apnea?

Do you suffer from Sleep apnea? Do you snore at night? Sleep apnea, a sleep disorder characterized by pauses in breathing during sleep, lasts long enough so that one or more breaths are missed, and such episodes occur repeatedly throughout sleep. Common signs and symptoms include gasping, choking  or silences during sleep, sudden awakening during sleep, loud snoring and daytime sleepiness. Not only can sleep apnea affect your energy levels throughout your day, but chronic sleep apnea carries potentially dangerous health affects. Thankfully, your dental professional can help!

Sleep apnea (a lack of oxygen) carries heightened risk of cardiovascular disease, stroke, high blood pressure, arrhythmias, diabetes, and sleep deprived driving accidents. Stroke is associated with obstructive sleep apnea as well, as sufferers have a 30% higher risk of heart attack or premature death than those unaffected. Risk factors can often be managed easily without major medical intervention. Being overweight or obese, nasal congestion or blockage and relaxed tongue/throat muscles often contribute to sleep apnea. Avoiding intake relaxants like alcohol or sedatives can play an important role in reducing the occurrence of sleep apnea.

There are three basic types of sleep apnea. Obstructive Sleep Apnea (OSA) is the only type of sleep apnea that can be treated by your dentist. Central Sleep Apnea is when a person’s brain “forgets” to signal the chest muscles to breathe during sleep. This variation of sleep apnea requires medication prescribed by your physician. Mixed Sleep Apnea is a combination of the preceding two types, and is the most difficult type of sleep apnea to diagnose and treat.

What can be done about sleep apnea – and how can your dentist play a role? The first step is diagnosis View definition in a new window. Sleep apnea is diagnosed with a “sleep study”. An individual with sleep apnea is rarely aware of having difficulty breathing, even upon awakening, and is recognized as a problem by others witnessing the individual during episodes or is suspected because of its effects on the body. Symptoms may be present for years without identification, during which time the sufferer may become conditioned to the daytime sleepiness and fatigue associated with significant levels of sleep disturbance.

Once a breathing problem during sleep has been established, there are two main routes of therapy for mild or moderate sleep apnea. The first is Oral Appliance Therapy, to reposition your lower jaw into a forward and downward position, opening up your throat, typically given by your dental care professional or physician. There are several designs from a simple diagnostic one to more sophisticate double jaw design. Your treating health professional will help to determine which would fit you better.

Oral appliance designed to keep the airway open during sleep.

For more severe cases, the use of a continuous positive airway pressure (CPAP) device can help, which ‘splints’ the patient’s airway open during sleep by means of forcing pressurized air into the throat. The CPAP machine assists only inhaling, whereas a BiPAP machine assists with both inhaling and exhaling and is used in more severe cases. Home remedies to treat sleep apnea include loose weight, treating allergy to decrease the volume of inflamed soft tissue of the airway, using a humidifier (in conjunction with the CPAP machine), trying a saline nasal spray before sleep.

If you have been diagnosed with OSA and think your dentist can help, be sure to bring your concerns to his or her attention.