Dentaltown March 2014 - (Page 97)

hygiene and prevention perio reports How Many Times Do You Swallow Every Hour? Swallowing frequency varies widely among individuals. Exactly what initiates the swallowing reflex is unknown. It might be related to the amount of saliva accumulating or when saliva reaches specific receptors. The absolute size of the oral cavity will influence how much saliva accumulates and how soon it reaches receptors. Measuring how often someone swallows is difficult as the person knows the swallows are being measured and they become more aware of them and perhaps bias the results. Researchers at the University of Minnesota evaluated 128 first-year dental students to determine the relationship between saliva flow and frequency of swallowing. The group consisted of 76 males and 52 females. A microphone was taped to the neck, near the larynx, to record swallowing noises. Subjects were asked to sit quietly and read for 30 minutes and push a button every time they noticed themselves swallowing. To estimate saliva volume swallowed, subjects were asked to swallow and then hold the saliva in their mouth for their particular average time between swallows and then expectorate all the saliva into a tube. This was repeated four times for each individual. The average number of swallows per hour was 122, with a range of swallows per hour from 18 to 400 - quite a wide variation. Saliva flow was greater in males compared to females. Those who swallowed frequently had high flow rates with small saliva volumes. Those who waited a long time between swallows had low flow rates with high volume. Perio Reports Vol. 26, No. 3 Perio Reports provides easy-to-read research summaries on topics of specific interest to clinicians. Perio Reports research summaries will be included in each issue to keep you on the cutting edge of dental hygiene science. Clinical Implications: The number of times a person swallows each day depends on saliva flow and volume. n Rudney, J., Ji, Z., Larson, C.: The Prediction of Saliva Swallowing Frequency in Humans from Estimates of Salivary Flow Rate and the Volume of Saliva Swallowed. Arciv Oral Biol 40:(6) 507-512, 1995. www.hygienetown.com How a Person Swallows Impacts Dentofacial Development There is much debate in the orthodontic community about the influence of the tongue on facial development. Some believe the tongue muscle function influences bone and jaw development while others believe the tongue merely adapts to the genetically predetermined oral environment by changing swallowing and speech patterns to fit. If the tongue muscle does in fact exert forces on bone through abnormal swallowing patterns, this should be taken into consideration before beginning orthodontic treatment, to prevent relapse. Researcher in Taipei, Taiwan evaluated 112 adults during swallowing to determine the impact on dentofacial morphology. They used computer-aided ultrasonography, cephalometreic radiography and study models. The cushion scanning technique (CST) used a framework that the patient leaned his/her forehead against and a cushion under the chin and on the front of the throat that did not interfere with swallowing. Swallowing was divided into five phases, depending on which part of the tongue was in contact with the palate. Swallowing was done with saliva only. There was significant correlation between tongue movements during swallowing and the structure of the face and jaw. Swallowing for a longer time when the back of the tongue contacted the palate, the end of swallowing, led to increased arch length and increased palatal depth. Despite significant correlations, they failed to show a cause-and-effect relationship between swallowing and dentofacial form. More factors need to be considered together with swallowing, including genetics, other forces from the lips and cheeks, resistance of the teeth and alveolar arch and resting posture of the tongue. Clinical Implications: The relationship between the teeth, tongue, bone and development is both complex and inconclusive. n Cheng, C., Peng, C., Chiou, H., Tsai, C.: Dentofacial Morphology and Tongue Function During Swallowing. Am J Orthod Dentofacial Orthop 122: 491-9, 2002. continued on page 98 dentaltown.com « MARCH 2014 97 http://www.hygienetown.com http://www.dentaltown.com

Table of Contents for the Digital Edition of Dentaltown March 2014

Dentaltown.com Highlights
Howard Speaks: “Ethical Dilemma” — a Series Kickoff
Professional Courtesy: Happy Birthday to Us!
Continuing Education Update
Start-up Equipment List – Now I’m Lost
Hygienist Doesn’t Want to Use Cavitron on Patients with Infection Disease History
Floorplan Feedback Requested
Honey, I Shrunk the Retirement
How to Manage Your Online Reputation
Corporate Profile: Glidewell Laboratories
Chair Trends 2014
I Hate Love Dentures
Special Lab Section: Communicating with Your Lab
Product Profile: Authentic Dental Lab
Office Visit: Small Town Practice, Big Time Technology
Eight Essential Elements of an Ideal Dental Office Design
Ad Index
Dentaltown Research: Marketing
Small Diameter Implants
In This Section: Implications of Ankyloglossia
Perio Reports
Profile in Oral Health: Breastfeeding and Dentistry: an Important Combination
Dentally Incorrect

Dentaltown March 2014