Orthodontists’ and parents’ perception of finished occlusion and willingness to extend treatment time


Patients and parents want shorter treatment times, but it is unclear whether they would compromise outcome quality to shorten treatment. The purpose of this study was to compare orthodontists’ and parents’ perceptions of finished occlusion and their willingness to extend treatment time to achieve improved outcomes. The effects of elapsed treatment time and patient compliance were also investigated.


Parallel surveys for orthodontists (n = 1000) and parents (n = 750) displayed simulated treatment outcomes of well-aligned teeth with occlusions in 1 mm increments from 3 mm Class III to 3 mm Class II. Participants rated their preferences on a visual analogue scale (VAS; 0-100) and specified whether they would extend treatment, and for how long, to improve the occlusion.


Two hundred thirty-three orthodontists (23%) and 243 parents (32%) responded. Despite differences between the scores given ( P < 0.0001), both groups rated Class I occlusion most acceptable (mean VAS = 93.9 and 80.7, respectively) and 3 mm Class III malocclusion least acceptable (mean VAS = 25.9 and 40.9, respectively). Parents were willing to extend treatment more often and for a greater time than orthodontists to improve results ( P < 0.0001). In addition, parents were less willing to terminate treatment early ( P < 0.05). Both groups perceived existing outcomes as more acceptable if the patient was noncompliant ( P < 0.05), but elapsed time in treatment had no significant effect on ratings.


For outcomes with well-aligned teeth, orthodontists and parents agreed on what the most and least acceptable occlusal relationships were. To achieve better outcomes, parents were willing to extend treatment duration more often and for a greater time than were orthodontists. In addition, parents were less willing than orthodontists to terminate treatment early.


  • The Class I occlusion was the most acceptable outcome for orthodontists and parents.

  • The 3 mm Class III malocclusion was the least acceptable outcome for orthodontists and parents.

  • Parents were more willing than clinicians to extend treatment time to improve outcomes.

  • Parents were less willing than orthodontists to terminate treatment early.

  • Orthodontists were more willing to extend treatment time for compliant patients.

The length of orthodontic treatment is important to patients and their parents as they begin orthodontic therapy. Factors affecting the duration of treatment have been investigated and include patient compliance and the severity of the initial malocclusion. The average treatment time among private practice orthodontic offices ranges from 23.1 months to 28.6 months. , However, orthodontists and patients desire shorter treatment times.

Patient cooperation and compliance levels vary among patients. Studies have shown that poor compliance may lead to increased treatment times and are associated with the following factors: patients’ sex (males are less cooperative than females), increased missed appointments, broken brackets, and inadequate oral hygiene. In addition, poor compliance may cause orthodontists to end treatment early. Mehra et al found that most orthodontists reported terminating treatment early in as many as 5%-10% of their patients because of poor compliance.

Orthodontists weigh the decision to continue treatment against the potential risks of developing white spot lesions, apical root resorption, periodontal defects, and continued lack of compliance. The decision to continue or prematurely end treatment is further complicated when the patient’s chief concern has been addressed, functional occlusion established, and parents and/or patients want to cease treatment before the attainment of an ideal occlusion. Although adolescent patients’ concerns should be considered during treatment, ultimately, treatment decisions are determined by the legal guardian—most commonly the parent. By determining discrepancies between the orthodontists’ and parents’ perceptions of treatment outcomes, the orthodontist can better address patients’ and parents’ expectations. ,

With patients’ and parents’ concerns regarding treatment length and demands for improved smile esthetics, more information is needed to determine the extent to which patients and parents desire to compromise the overall treatment outcome for shorter treatment duration. If patients or parents are willing to compromise treatment outcomes, the orthodontist also needs to decide whether they are willing to compromise their standards of care to meet patients’ and parents’ lowered expectations.

The purpose of this study was to determine whether there were differences between orthodontists’ and parents’ perceptions of finished occlusion quality and their willingness to extend treatment time to achieve improved outcomes. The influence of elapsed treatment time and the level of patient compliance were also investigated. The null hypothesis was that there would be no differences between orthodontists’ and parents’ perceptions of finished occlusion quality or willingness to extend treatment times to improve outcomes.

Material and methods

After approval from the Institutional Review Board of Virginia Commonwealth University, 2 parallel surveys were developed using images from monochromatic digital models. The iTero HD2.9 intraoral scanner (Align Technology, San Jose, Calif) was used to generate the digital images using a finished patient from the university orthodontic practice. The inclusion criteria for the intraoral scan were a fully erupted permanent dentition except for third molars, no tooth-size discrepancy, maxillary and mandibular incisor angulation within normal limits, ideal alignment of teeth, and ideal Class I molar–canine relationship.

The digital models were altered by moving the mandibular arch in 1.0 mm increments up to 3.0 mm anteriorly and 3.0 mm posteriorly using OrthoCAD software (version 5.1; Align Technology). Seven occlusal variations resulted: 3 mm Class III, 2 mm Class III, 1 mm Class III, Class I, 1 mm Class II, 2 mm Class II, and 3 mm Class II. For each variation, the right buccal, center, and left buccal images were displayed ( Fig 1 ). The vertical and transverse dimensions were held constant except for the 2 mm Class III malocclusion image, which was increased vertically and digitally altered using Adobe Photoshop (Adobe Systems Incorporated, San Jose, Calif) to depict an edge to edge anterior occlusion.

Fig 1
Digital models representing 3 mm Class II (A) , ideal Class I (B) , and 3 mm Class III malocclusion (C) .

The orthodontist surveys were mailed to 1000 orthodontists in 2016 who were randomly selected from a geographically weighted representation of all active U.S. members of the American Association of Orthodontists. Initial nonresponders received a second mailing 6 weeks after the initial mailing. The parent surveys were given to 750 parents of children currently in active orthodontic treatment. Parent participants were selected from 15 different orthodontic offices, located in 3 states. The parent surveys were delivered to each participating office during the same period that orthodontist surveys were being conducted. Each of the 15 offices received 50 questionnaire packets.

Using a 100 mm visual analogue scale (VAS) anchored by “least acceptable” and “most acceptable,” participants were asked to mark their assessment for each of the various occlusal relationships. The order of the sets was randomized using a random number generator within Microsoft Excel (Microsoft Corporation, Redmond, Wash). All VAS scores were measured using a digital caliper (model 54-100-77-2; Fred V. Fowler Co Inc, Newton, Mass) by 2 examiners (D.L. and J.D.). Interrater and intrarater reliability were determined by having each examiner independently measure 50 VAS scores, then repeating the measurements 7 days later.

To evaluate the effect of compliance on perceptions of treatment outcomes, participants completed separate VAS measurements (one assuming the treatment outcome was from a compliant patient and one from a noncompliant patient) for each malocclusion presented. For this study, compliance was defined by ideal patient attendance to appointments, good oral hygiene, elastic wear, and adherence to instructions given by the orthodontist. To investigate if the amount of time in treatment influenced the orthodontists’ and parents’ perception of treatment outcome or willingness to extend or terminate treatment, we presented each outcome as either being after 18 months or 24 months of completed orthodontic treatment (total of 28 different scenarios). In addition, for each malocclusion, compliance level, and elapsed treatment time, participants selected the number of months they would be willing to continue treatment to achieve an ideal outcome.

Statistical analysis

Study data were collected and managed using REDCap (Research Electronic Data Capture) software (Vanderbilt University, Nashville, Tenn) hosted at Virginia Commonwealth University. Outcome acceptability (VAS score of 0-100 mm) and additional treatment time were estimated using repeated measures analysis accounting for variability among respondents. Parameters included in all models were the respondent type (orthodontist or parent), specific malocclusion depicted, elapsed treatment duration (18 or 24 months), and compliance. In addition, 2-way interactions were fit to determine potential differences on the effect of malocclusion, treatment time, and patient compliance between orthodontists and parents. All post-hoc pairwise comparisons were adjusted using Tukey’s honestly significant difference to account for multiple comparisons. A significance level of 0.05 was set for all statistical models. SAS Enterprise Guide (version 6.1; SAS Institute, Cary, NC) was used for all analyses.


The response rates were 23% (n = 233) for orthodontists and 32% (n = 243) for parents ( Table I ). For orthodontists, 78% of respondents were male, and 22% were female, with 38% of the total respondents certified by the American Board of Orthodontics. For parents, 14% of respondents were male, and 86% were female. Intrarater reliability was high for each examiner (D.L., 0.998 and J.D., 0.999), and interrater reliability was also high (intraclass correlation coefficient, 0.95).

Table I
Survey demographics
Demographics n %
Response rate 243 32
Male 33 14
Female 203 86
Age, y
25-34 24 10
35-44 110 46
45-54 86 36
55-64 15 6
≥65 3 1
Male 107 45
Female 130 55
Age, y
8-10 8 3
11-13 130 55
14-16 92 39
≥17 7 3
Months of treatment completed
1-6 52 22
7-12 42 18
13-18 100 43
19-24 23 10
Response rate 233 23
Male 181 78
Female 50 22
ABO certified 87 38
Years in practice
1-10 57 25
11-20 69 30
21-30 56 24
31-40 37 16
≥41 13 6
Only gold members can continue reading. Log In or Register to continue

Jan 9, 2021 | Posted by in Orthodontics | Comments Off on Orthodontists’ and parents’ perception of finished occlusion and willingness to extend treatment time
Premium Wordpress Themes by UFO Themes