THE READERS' CORNER
This month's topics are tooth-whitening systems and incisor position and angulation.
1. Do you use any tooth-whitening procedures in-office? Describe the product and method ofapplication.
The majority of respondents did not use anyin-office tooth-whitening procedures, but didadvise their patients to use home whitening products.Those who did bleaching in the office usedvarious methods, but there was no indication thatany particular brand was preferred over others.Products mentioned were Prestige Paste (RaintreeEssix), Nite White Excel (Discus Dental),Nupro Gold (Dentsply), Opalescence carbamideperoxide (Ultradent) and bleaching trays, BriteSmile (commercial offices), and a bleaching gelapplied in an Essix retainer at night.
Several clinicians were reluctant to use in-officetooth-whitening procedures because theirgeneral dentist referrers felt that tooth whiteningwas within their purview rather than the orthodontist's.Also, some respondents believed it waspreferable to use the whitening products afterfixed appliances were removed to avoid anyunevenness in color in the bracket areas.
A specific comment was:
How do you measure the effectiveness of the procedure?
Several ways to measure effectiveness werelisted, but the most common was a comparison ofbefore-and-after shades using the guide includedin the whitening kit. Also mentioned were photographiccomparisons, patient satisfaction, andwhitening the upper arch first and then checkingit against the unwhitened lower arch.
What commercial products do you recommend topatients for home use?
By far the most recommended product forhome use was Crest White Strips, followed byRembrandt Plus toothpaste. Many of the respondentsleft the recommendations to the familydentists. Several said they let their patientsdecide, as long as the products were certified bythe ADA.
What percentage of your patients do you estimateare using tooth-whitening products?
There was a wide range of estimates, from5% to 95%, but the average was around 27%.
Do you find that toothpastes that claim tooth-whiteningability are effective?
About two-thirds of the respondents did notbelieve that whitening toothpastes were effective.Many of them felt that the effects of these productswere minor, and that it was difficult to quantifyany change in tooth color. There were alsomany comments indicating that the productswere not strong enough or not applied longenough to have any discernible effects.
Other clinicians thought the whiteningtoothpastes were somewhat effective if used incombination with Crest White Strips or paint-onbleaching products.
Teeth vary in color: for example, cuspids aregenerally darker than incisors. Are tooth-whiteningproducts equally effective on all teeth?
There was a relatively even distribution ofreplies to this question. About one-third of therespondents believed that tooth-whitening productswere effective on all teeth, another thirdbelieved they were not, and the remaining thirdhad no definite opinion. The most frequent commentwas that teeth tended to lighten proportionatelyto their original colors.
Some specific comments:
Do you find that certain toothpastes prevent orcorrect discoloration around bonded brackets?
A substantial majority did not believe thattoothpastes could prevent or correct discolorationaround bonded brackets. On the otherhand, a few clinicians did not want their patientsusing whitening toothpastes while in fixed appliancesbecause, when the bonded appliances wereremoved, there could be a color disparity betweenthe areas where the patient brushed andthe areas under the bonded brackets.
Individual responses included:
Do you find that certain toothpastes prevent discolorationof clear "O" ties used with ceramicbrackets?
Only one respondent believed that the useof a whitening toothpaste could avoid discolorationof clear "O" ties. There was also a remarkthat baking-soda paste could prevent discolorationof these ligatures.
Specific comments were:
2. Do you base your treatment plan on the positionof the upper incisors or the lower incisors,and in relationship to what landmark?
The respondents were fairly evenly dividedbetween the upper incisors and the lowerincisors, with a slight advantage to the positionof the lower incisors. An equal number, however,used the positions of both the upper and lowerincisors in their treatment planning.
Landmarks were varied, with the A-pogonionline the most cited, closely followed by theincisor mandibular plane angle, the mandibularplane angle, the "E" line, and the upper incisaledge to the upper lip. There were numerous commentsthat more than one reference plane orlandmark was used in constructing the treatmentplan, with emphasis on facial balance rather thanon any cephalometric reference.
Individual remarks included:
How much are you willing to compromise thatrelationship to avoid extraction?
The most frequent response was "some".There was a general tendency not to adhere toany strict cephalometric norm or analysis, or tospecific tooth positions. The reasons given forbeing more flexible included abnormal growthpatterns, racial norms, periodontal concerns, profileconsiderations, variations in informed consent,and avoidance of surgery.
Some specific comments were:
What is your criterion for the angulation of theupper incisors?
Again, it was apparent that the cliniciansdid not dogmatically follow any particular criteria.The most common answer was that the angulationof the upper incisors was correlated withthe patient's facial esthetics, and that estheticsdepended not only on skeletal considerations, butalso on soft-tissue proportions. There was a specificconcern about the harmony between theface and the position of the upper lip. Severalclinicians, however, indicated angulations oramounts they were willing to compromise, suchas 22° ± 5° to NA with the maxilla in normalposition and an interincisal angle of 130-140°.
Does this vary depending on mandibular planeangle or depth of bite? And can you alwaysachieve your treatment goal?
Fully 81% of the respondents said their criterionfor angulation of the upper incisor variedwith the mandibular plane angle or the depth ofbite, and that they could not always achieve it.Their rationale centered, again, on facial considerations.Other strong indicators were a steep orlow mandibular plane angle, a skeletal tendencyto Class II or Class III, the vertical dimension,the position of the upper incisor within the corticalplate, the angulation of the lower incisor,patient compliance, and the insistence of someadult patients on nonextraction treatment.
Representative comments included:
What is the significance of the interincisal anglein treatment planning?
The responses were varied, with an emphasison the importance of the interincisal angle inpositioning the incisors to fit the face and to giveadequate and esthetic support to the upper lip.Other clinicians noted that a proper interincisalangle contributed to better function and stability.On the other hand, 13% believed that there was"not much" significance to the interincisal angleor that it was simply a guide.
Some specific remarks:
Is there an ideal interincisal angle?
About 40% of the respondents felt therewas an ideal interincisal angle for each particularcase, but not for general populations. Theremainder thought there was no ideal interincisalangle, or that there was merely an acceptablerange that could be used for reference.
One candid comment was:
Will an obtuse interincisal angle necessarily leadto bite closure?
More than 80% of the clinicians did notbelieve that an obtuse interincisal angle wasdirectly correlated with bite closure. Their reasonswere varied, including: muscle strength andposterior tooth support are more important; notwhen there is good occlusion of the posteriorteeth; it depends on the mandibular plane angle;not in high-angle cases; the skeletal patternrather than the interincisal angle could be the reasonfor the status of the bite; and only if the caseis not retained properly.
A specific reply:
JCO would like to thank the following contributorsto this month's column:
Dr. H. Eldon Attaway, Irving, TX
Dr. Robert R. Conner, Moraga, CA
Dr. Greg Costopoulos, Novato, CA
Dr. Gary J. Dilley, Cary, NC
Dr. Jennifer Eisenhuth, White Bear Lake, MN
Dr. Austin W. Feeney, New Canaan, CT
Dr. Thomas C. Flanagan, Chattanooga, TN
Dr. C. Steven Gulrich, Foxboro, MA
Dr. Curtis L. Hayden, Manhattan, KS
Dr. L. Clark Hodge, Gainesville, FL
Dr. Gary P. Horvath, Spartanburg, SC
Dr. Jaime de Jesús Viñas, Hato Rey, PR
Dr. Vaughn A. Johnson, Durango, CO
Drs. Lawrence A. Klar, Neal A. Klar, and Marni E. Voorhees, Virginia Beach, VA
Dr. Christopher K. Klein, Mt. Vernon, IL
Dr. Lee R. Logan, Northridge, CA
Dr. John D. Meschke, Hutchinson, KS
Dr. Michael D. O'Leary, Wisconsin Rapids, WI
Dr. Bernard J. Orlowski, Woodbridge, NJ
Dr. Thomas Robinson, Sault Ste. Marie, MI
Dr. J. Mike Rowan, Jr., Tyler, TX
Dr. John Russell III, Columbus, MS
Dr. David L. Schmidt, Universal City, TX
Drs. Gary D. Schuller, John R. Tibbetts, and Jonathan B. Schlosser, Williamsville, NY
Dr. J. Haldane Soutar, Miami Shores, FL
Dr. Lewis C. Walker, Jacksonville, FL
Dr. James Weissman, Encino, CA
Dr. John A. Yoffe, Harrisburg, PA