Texas Dental Journal l www.tda.org l March 2012 265

The KPG Index – A Novel 3D Classification System for Maxillary Canine ImpactionsDaniel E. San Martín, DDS, MSD; Jeryl D. English, DDS, MS; Chung H. Kau, BDS, MScD, MBA, MOrth, PhD, FDS, FFD, FAMS; Ronald L. Gallerano, DDS, MSD; Kathleen R. McGrory, DDS, MS; Anna M. Salas, DDS, MS; Jerry Bouquot, DDS, MS; James J. Xia, MD, PhD

AbstractIntroduction: Advancements in Cone Beam Computed Tomography (CBCT) have improved localization of impacted canines. The KPG index is the first 3-D classification system for classifying the position of canines based on their distance from the norm (1). The aim of this study was to determine if this index provides an estimate of the time necessary to treat an impacted canine using closed eruption. Materials and Methods: CBCT scans of 28 impacted canines at The University of Texas School of Dentist-ry at Houston Department of Ortho-dontics were classified using the KPG index. The scores and categories were compared to the time from surgi-cal exposure to proper positioning.Results: Four canines were classified as “Easy,” 11 as “Moderate,” 9 as “Dif-ficult,” and 4 as “Extremely Difficult.” Average treatment times associated in months were: “Easy” — 11.23, “Mod-erate” — 11.36, “Difficult” — 12.76, and “Extremely Difficult” — 13.23.Conclusions: The KPG index cur-rently cannot be confirmed as an accurate means of estimating treat-ment time for an impacted canine. Further verification studies should include larger sample sizes and com-pare differing mechanics. However, there are limitations to 2-D imaging; therefore, the 3-D CBCT images and the KPG index, with further validation, will become increasingly valuable to orthodontists.

KEy wORDS: MESH terms: cus-pid/radiography, image enhancement/methods, imaging, three-dimensional/methods, pattern recognition, auto-mated/methods, radiographic image interpretation, computer-assisted/methods, radiography, dental/meth-ods, reproducibility of results, tomog-raphy, X-ray computed/methods, tooth, impacted/radiography

Tex Dent J 2012; 129(3):265-274.

Introduction The specialty of orthodontics is filled with a variety of chal-lenges that require careful diagnosis and planning; one of these challenges involves impacted maxillary canines. To enact a treatment plan after diagnosis, it is necessary to correctly de-termine the exact location of the impacted tooth. Historically, 2-D radiographs were used to localize these teeth, and the prediction of treatment time was based purely on the orthodon-tist’s experience. With the recent advancements of Cone Beam Computed Tomography (CBCT) imaging, a practitioner has access to an abundance of information regarding an impaction (2).

C L I N I C A L R E P O R T

English Kau

Dr is a practicing or-thodontist in San Antonio, Texas.Dr English is the chair and a pro-fessor, Department of Orthodon-tics, University of Texas School of Dentistry at Houston (UTSD).Dr Kau is the chair, Department of Orthodontics, University of Alabama School of Dentistry.Dr Gallerano is a clinical as-sociate professor, Department of Orthodontics, UTSD.Dr McGrory is a clinical director and clinical assistant professor, Department of Orthodontics, UTSD.Dr Salas is a clinical associate professor, Department of Ortho-dontics, UTSD.Dr Bouquot is the chair and a professor, Department of Diag-nostic and Biomedical Sciences, UTSD.Dr Xia is an associate professor of orthodontics, Department of Pediatric Surgery, University of Texas Medical School at Houston.Correspondence: Daniel E. San Martín, DDS, MSD, 7339 Eagle Ledge, San Antonio, TX 78249; Phone: 210-392-2321; Fax: 713-500-4123; E-mail: daniel.e.san.martin@gmail.com.

The authors have no declared potential conflicts of financial interest, relationships, and/or affilia-tions relevant to the subject matter or materials discussed in the manuscript.

This was peer reviewed.article

Bouquot Xia

Gallerano McGrory Salas

2 0 1 2 S P E A K E R SDr. David Ahearn

Dr. Edward Pat Allen

Dr. John Alonge

Dr. Linda Altenho�

Dr. Robert Anderton

Ms. Nancy Andrews

Mr. Thomas Angeloni

Mr. David Avery

Dr. Herbert Bader

Ms. Lois Banta

Dr. Joyce Bassett

Ms. Judy Bendit

Dr. Joel Berg

Ms. Jen Blake

Mr. Frank Brown

Dr. William “Bo” Bruce

Dr. John Burgess

Dr. Ellen Byrne

Mr. Tim Caruso

Dr. Gerard Chiche

Dr. Gordon Christensen

Dr. Tom Cockerell

Dr. Sarah Conroy

Dr. Robert Convissar

Dr. Harold Crossley

Ms. Karen Davis

Dr. Robert Dew

Ms. MaryAnn Digman

Dr. Scott Dyer

Dr. Robert Edwab

Dr. Catherine Flaitz

Dr. Michael Fling

Dr. John Flucke

Dr. Marie Fluent

Ms. Ellen Gambardella

Dr. Carlos Garcia

Dr. Gretchen Gibson

Dr. Jason Gillespie

Dr. Tom Glass

Dr. Kelly Halligan

Dr. Mel Hawkins

Dr. Van Haywood

Dr. Harald Heymann

Dr. Michaell Huber

Dr. Mark Hyman

Dr. Arthur Jeske

Dr. Warren Karp

Dr. Mark Kleive

Dr. David Kumamoto

Dr. Doug Lambert

Dr. Sonia Leziy

Dr. David Little

Ms. Debra Locke

Dr. Sam Low

Mr. Jason Luse

Dr. Robert Margeas

Dr. Will Martin

Mr. Orlando Martinez

Mr. Chris Maurer

Dr. Jim McKee

Dr. Brahm Miller

Dr. John Molinari

Dr. Jaimee Morgan

Dr. Dean Morton

Mr. Je�rey Moss

Dr. Linda Niessen

Dr. John Olmsted

Mr. Chris Page

Dr. Edwin “Ted” Parks

Dr. Stan Presley

Dr. Greg Psaltis

Ms. Mary Ellen Psaltis

Dr. Willis Pumphrey

Dr. Steve Ratcli�

Ms. Karen Reisman

Dr. James Ruskin

Mr. Chris Scappatura

Dr. David Scarfe

Dr. John Schmitz

Dr. David Schwab

Ms. Laurie Semple

Dr. Sam Simos

Ms. Lynn Smiley

Ms. Elizabeth Somer

Dr. John Sorensen

Dr. Jamison Spencer

Dr. Samuel Strong

Dr. Michael Swick

Dr. Terry Tanaka

Dr. Dennis Tarnow

Mr. Marcel Tetzla�

Dr. Paul Tiwana

Dr. Martin Trope

Dr. Terry Watson

Mr. Dave Weber

Dr. Clark Whitmire

Ms. Rebecca Wilder

Dr. DeWitt Wilkerson

Ms. Gail Williamson

Dr. Thomas Wilson

Dr. John Wright

TDA is an ADA CERP Recognized Provider

REGISTRATIONRegister & Select Courses Today!Pre-Reg Deadline: April 5, 2012 TEXAS

the

M E E T I N G142nd Annual Session of the Texas Dental Association

May 3-6, 2012 texasmeeting.com

HOUSINGBook Hotel Reservations Now For The

Best SelectionHousing Deadline: April 5, 2012

For additional information about the meeting, pleasecontact Donna Musselman, donna@tda.org or Ann

Pargac, ann@tda.org, or call 512.443.3675.

San Martín

San Martín

Texas Dental Journal l www.tda.org l March 2012 289

Cone Beam Computed Tomography Imaging in the Evaluation of the Temporomandibular JointOriginally published in the Journal of the California Dental Association: Barghan S, Merrill R, Tetradis S, Cone Beam Computed Tomography Imaging in the Evaluation of the Temporomandibular Joint. J Cal Dent Assoc 38(1):33-39. 2010. © 2010, California Dental Association. Reprinted by permission. Images reprinted with permission from Sevin Barghan, DDS, MSc, research associate at UCLA School of Dentistry.

Sevin Barghan, DDS, MScRobert Merrill, DDS, MSSotirios Tetradis, DDS, PhD

Abstract

A radiological examina-tion is an essential part of the diagnosis and management of temporo-mandibular joint disease. Accurate evaluation of the TMJ has been difficult due to the superimposi-tion of other structure in conventional radiographs. Cone beam computed tomography provides precise imaging of TMJ anatomy without super-imposition and distortion. The CBCT’s preciseness enables practitioners to better identify problems, as well for other strate-gies. Common condi-tions of the TMJ in which CBCT plays a role are discussed.

KEy wORDS:Cone-Beam Computed Tomography/methodsTemporomandibular Joint/radiography

Tex Dent J 2012; 130(3): 289-302.

Although the use of computed tomography (CT) as a di-

agnostic tool has been an indispensable in medicine for

many years, its application in dentistry has been more

limited. This was mainly due to the rather high cost of the

equipment, the large space required for its operation, and

the high dose of radiation involved. The use of CT results

in significantly higher absorbed doses compared with

panoramic radiography and linear tomography. It has

therefore been of great concern whether the superiority of

CT in terms of imaging outweighs the biological risks for

the patient (1-3). Nevertheless, the number of CT exami-

nations in dentistry has rapidly increased in recent years,

particularly for examination of pathological conditions

and trauma in the maxillofacial region (4-7).

Dr Barghan is a visiting assistant professor, Section of Oral and Maxil ofacial Radiology,lUniversity of California, Los Angeles, School of Dentistry.

Dr Merrill is an adjunct professor and director of Graduate Orofacial Pain and Dental Sleep Medicine Program, University of California, Los Angeles, School of Dentistry.

Dr Tetradis is a professor and chair, Section of Oral and Maxillofacial Radiology, University of California, Los Angeles, School of Dentistry.

To request a printed copy of this article, please contact Sevin Barghan, DDS, MSc, University of California, Los Angeles, School of Dentistry, 53-068 CHS, 10833 Le Conte Ave, Los Angeles, CA 90095-1668.

C L I N I C A L R E P O R T

Join us in Philadelphia this June to enjoy the freedom of earning an entire year’s worth of continuing education in one great location! This year’s educational program includes:

• “Key Implant Position and Implant Number: A Biomechanical Rationale to Treatment Planning,” Carl E. Misch, BS, DDS, MDS, PhD (hc)

• “Advanced Oral Surgery Techniques for Smoother, Easier, Less Stressful Procedures,” Karl Koerner, DDS, FAGD, MS

• “What’s Hot and What’s Getting Hotter,” Howard S. Glazer, DDS, FAGD

• “The Occlusal Secrets You Should Have Learned in Kindergarten: Or, How to Take Your Practice to the Next Level,” Irwin Becker, DDS

REGISTER TODAY!www.agd.org/philadelphia

Join us in Philadelphia this June to enjoy the freedom of earning an entire year’s worth of continuing education in one great location! This

You’ll learn tips and techniques you can use as soon as you get back to the office. And don’t forget your staff —we’ve planned a variety of practical educational opportunities for them, too!

See the latest dental equipment

and materials in our Exhibit Hall with

more than 200 exhibitors!

AGD_Philly AD 2_12 TDJ .indd 1 1/30/12 10:00 AM

Texas Dental Journal l www.tda.org l March 2012 277

Calibration of Equipment for Analysis of Drinking Water Fluoride: A Comparison Study Ryan L. Quock, DDS

Jarvis T. Chan, DDS, PhD

AbstractCurrent American Dental Association evidence-based recommendations for pre-scription of dietary fluoride supplements are based in part on the fluoride concentration of a pediatric patient’s drinking water. With these recommendations in mind, this study compared the relative accuracy of fluoride concentration analysis when a common ap-paratus is calibrated with different combina-tions of standard values. Fluoride solutions in increments of 0.1 ppm, from a range of 0.1 to 1.0 ppm fluoride, as well as 2.0 and 4.0 ppm, were gravimetrically prepared and fluoride concentration measured in pentad, using a fluoride ion-specific electrode and millivolt meter. Fluoride concentrations of these solutions were recorded after calibra-tion with the following 3 different combina-tions of standard fluoride solutions: 0.1 ppm and 0.5 ppm, 0.1 ppm and 1.0 ppm, 0.5 ppm and 1.0 ppm. Statistical analysis showed significant differences in the fluo-ride content of water samples obtained with different two-standard fluoride solutions. Among the two-standard fluoride solutions tested, using 0.5 ppm and 1.0 ppm as two-standard fluoride solutions provided the most accurate fluoride measurement of water samples containing fluoride in the range of 0.1 ppm to 4.0 ppm. This informa-tion should be valuable to dental clinics or laboratories in fluoride analysis of drinking water samples.

KEy wORDS: drinking water, fluoride analysis, fluoride supplements

Tex Dent J 2012; 129(3):277-283.

IntroductionFluoride has been credited to play a key role in prevent-ing dental caries since the 1940s. Its well documented safety and efficacy in dental caries prevention have resulted in recommendations of its use for this purpose by the U.S. Public Health Service (1). One of the longest standing applications of fluoride use for caries preven-tion has been the fluoridation of community drinking water supplies. In recent years, the city of San Diego initiated fluoridation of its community water supplies (2,3), and the governor of Louisiana signed a bill pro-viding for an increase in the number of communities receiving fluoridated water in that state (4). Optimal fluoride concentration in public drinking water for car-ies prevention has been determined to range from 0.7 to 1.2 ppm, depending on the average maximum daily

S C I E N T I F I C R E P O R T

Quock Chan

Dr Ryan L. Quock is an associate professor, Department of Restorative Den-tistry & Biomaterials, University of Texas School of Dentistry at Houston.Dr Jarvis T. Chan is a professor, Department of Diagnostic and Biomedical Sciences, University of Texas at Houston School of Dentistry, an adjunct professor, Department of Integrative Biology and Pharmacology, University of Texas School of Dentistry at Houston.Correspondence: Ryan L. Quock, DDS, Department of Restorative Dentistry & Biomaterials, University of Texas School of Dentistry at Houston, 6516 MD Anderson Blvd Ste 493, Houston, TX 77030; Phone: 713-500-4276, Fax: 713-500-4108; e-mail: ryan.quock@uth.tmc.edu.The authors have no declared potential conflicts of financial interest, relation-ships, and/or affiliations relevant to the subject matter or materials discussed in the manuscript.This was peer reviewed.article

Free CE credits. Available 24/7.

To view courses online, visit www.txhealthsteps.com.

*Accredited by the UTHSCSA Dental School Office of Continuing

Dental Education, Texas Medical Association, American Nurses

Credentialing Center, National Commission for Health Education

Credentialing, Texas State Board of Social Worker Examiners,

Accreditation Council of Pharmacy Education, Texas Dietetic

Association, Texas Academy of Audiology, and International

Board of Lactation Consultant Examiners. Continuing Education

for multiple disciplines will be provided for these events.

CE Courses Include:• First Dental Home• Oral Health Examinations

by Dental Professionals• Oral Evaluations and

Fluoride Varnish• Children with Diabetes• Children with Asthma• Case Management• Texas Health Steps Overview• Many othersReferral Guidelines• Pediatric Depression• High Blood Pressures

in the Office• Atopic Dermatitis• Gastroesophageal Reflux

in Infants• Exercise-Induced Dyspnea • Referral Guidelines Overview

Taking New Steps

Now you can choose the time and place to take the courses you need and want. We’ve made

it easy to take free CE courses online. Dentists and dental hygienists can get 1 hour of free

CE credit for the First Dental Home and the Oral Health Examinations by Dental Professionals

courses. Learn more about Texas Health Steps (Medicaid for children) and other health-care

services with Texas Health Steps Online Provider Education.

The CE courses were developed by the Texas Department of State Health Services

and the Texas Health and Human Services Commission. All courses are accredited for

eligible participants.*

STEPS-0379 TxDental_8.75x11.25.indd 1 1/20/12 4:55 PM