Abstract
Objective:
To explore early treatment practices and perceptions among members of the American Association of Orthodontists (AAO).
Design:
Cross-sectional survey.
Participants:
Members of the AAO.
Methods:
An electronic questionnaire was pre-piloted and circulated via email to members of the AAO. The survey questions covered respondent demographics, clinical experience, preferred timing of intervention, treatment approaches and clinicians’ perceptions with regard to early interceptive treatment. Descriptive statistics were performed.
Results:
A total of 228 responses were obtained (response rate = 5.12%). Treatment was commonly timed using dental age (61%) and pubertal signs (61.8%). Several problems were treated in the mid-mixed dentition phase (8–9 years) including posterior crossbite (51.3%) increased overjet (41.7%), crowding (39.5%), space loss (41.23%) and anterior open bite (37.3%). Commonly reported treatment approaches included the use of sectional fixed appliances for treatment of anterior crossbite (81.6%), rapid palatal expander for treatment of posterior crossbite (63.6%) and anterior bite plane for deep overbite correction (62.7%). Herbst appliance (42.1%) and facemask (89%) were commonly prescribed for early correction of Class II and III, respectively. Lingual and palatal arches were commonly used to preserve arch length. The majority of respondents (60.1%) were proponents of two-phase orthodontic treatment.
Conclusions:
Early orthodontic treatment in the mid-mixed dentition stage was widely advocated for orthodontic intervention. Various malocclusions, including posterior and anterior crossbite, increased overjet, crowding, space loss and anterior open bite, were reported to be commonly addressed during this phase. Popular treatment approaches included sectional fixed appliances, Herbst appliance, facemask, rapid palatal expanders and anterior bite planes.
Keywords
Introduction
The timing of orthodontic treatment is a long-standing topic of debate between two schools of thought: one that upholds early treatment will reduce or eliminate the degree of expected malocclusion, and another that maintains the results achieved are generally unsustainable (Fleming, 2017; Wahl, 2006). However, despite a lack of solid evidence regarding its benefits, early orthodontic treatment remains a routine practice in many dental offices, with evidence demonstrating its efficacy in significantly reducing malocclusion severity in both Medicaid and private-pay populations (Mirabelli et al., 2005). The prominence of phase I treatment has increased significantly in recent years, especially in the United States, to the extent that some clinicians adopt a blanket prescription of phase I treatment for all young children (Bowman, 1998; Fleming, 2017). Unfortunately, the recommendation or ‘branding’ for phase I treatment primarily relies on empirical judgement and expert opinions, rather than being supported by evidence from clinical research (Bowman, 1998; Hsieh et al., 2005).
The benefits of phase I treatment are poorly understood, and the decision for early intervention is relatively subjective (Vasilakou et al., 2016). Thiruvenkatachari et al. (2015) showed that there were no significant differences in the clinical outcomes between children treated early and late for Class II malocclusion. However, early treatment reduced the risk of trauma by 33% and 41% in the functional and headgear groups, respectively (Batista et al., 2018). Ugolini et al. (2021) concluded that the evidence was insufficient to draw a conclusion regarding the efficacy of crossbite correction. However, for children in the early mixed dentition stage (ages 7–11 years), quad-helix and expansion plates were more beneficial than no treatment for correcting posterior crossbites. In addition, Mandall et al. (2010, 2012, 2016), in their clinical trial, found a reduction in the perceived need for orthognathic surgery after the use of a protraction facemask; however, there was a limited sustained skeletal effect.
Although a common justification for early orthodontic treatment is to reduce treatment time and complexity, few clinical studies have evaluated its long-term efficacy (Hsieh et al., 2005; Vasilakou et al., 2016). Hsieh et al. (2005) compared outcomes in patients who received early orthodontic treatment with those who underwent comprehensive treatment after mixed dentition. They found an increased treatment time, higher rate of decalcification and higher premature termination rate in the early treatment group (Hsieh et al., 2005). Moreover, clinicians argue that early interventions may benefit children by alleviating malalignment and thus facilitating improved oral hygiene (Bollen et al., 2008). However, other studies have shown insufficient evidence to support the benefits of orthodontic therapy on periodontal status (Bollen et al., 2008; Fleming, 2017). In addition, during early mixed dentition, the dexterity and behavioural determinants to maintain good oral hygiene have not fully developed (Huebner and Riedy, 2010), which could result in increased plaque accumulation and enamel decalcification (Toti et al., 2022).
The orthodontic literature has also shown that the clinical outcomes of early treatment in the mixed dentition stage are similar to those in the early permanent dentition stage (Batista et al., 2018; Hsieh et al., 2005). In addition, long treatment time associated with early treatment risks hindering patient compliance (Hsieh et al., 2005). It was reported that in the early treatment group for Class II patients, treatment duration was longer, costs were higher and final occlusal outcomes were poorer compared to the one-phase treatment group (O’Brien et al., 2009). Nevertheless, early treatment is justified if better long-term outcomes are expected or a second treatment phase is eliminated. Yet, the normal position of the permanent teeth is not guaranteed (Proffit, 2006). Further, in a retrospective cohort study that compared patients who received early treatment with a control, the effectiveness of interceptive treatment in reducing malocclusion was evident; however, the quality of the outcome was compromised (King and Brudvik, 2010). Other reported benefits of early treatment are the control of oral habits, modification of growth and facilitation of eruption (Kerosuo, 2002). Hence, clinicians may advocate for interceptive treatment to alleviate occlusal deviations and improve patients’ self-image. However, despite the available data suggesting that early treatment can be beneficial, it can also be costly, prolong the treatment duration and the occlusal outcomes may not be as good (O’Brien et al., 2009).
The timing of early treatment varies depending on the type of malocclusion (Proffit, 2006). For Class I malocclusion, there is consensus regarding the benefit of early treatment of posterior crossbite and the use of serial extraction in cases of severe crowding; however, the evidence is weak regarding the long-term efficacy of early expansion for crowding relief (Proffit, 2006). In their Cochrane review, Turner et al. (2021) indicated that current evidence, though of very low certainty, suggests that lip bumpers and Schwartz appliances may help prevent crowding in the mixed dentition.
However, the scope of the current practice pattern in the United States and the perceived merits of early treatment have yet to be determined. Therefore, the aim of the present survey-based study was to investigate the practices concerning timing and approach, as well as the perceptions related to early treatment among orthodontic specialists in the United States.
Methods
Survey
This survey-based study was approved by the Institutional Review Board at the University of Florida IRB no. 202201833. Following a thorough literature review to identify aspects relevant to early orthodontic treatment (NM, TL), the survey draft was developed (NM, TL, AS) and reviewed (DC). A preliminary electronic version of the survey was then created (Google Forms – online survey tool) comprising four sections and 17 questions. After this, 10 consultant orthodontists, each with more than 20 years of clinical experience, evaluated the content validity of the initial survey. Each question was scored on a three-point scale. The Content Validity Ratio (CVR) was then calculated for each question utilising ‘Lawshe’s Method’ (Lawshe, 1975). All questions were rated as ‘essential’ and therefore included in the final version of the questionnaire (Appendix 1). Questions related to demographics, clinical experience, timing and treatment approach to early treatment and clinicians’ perceptions were included.
Participants
The survey was approved by the American Association of Orthodontists (AAO) Partners in Research (PIR) program. It was then distributed to 4450 active members of the AAO in the United States twice via email with a reminder (April and June 2023). Participation in the survey was anonymous and voluntary.
Statistical analysis
Descriptive statistics were performed including frequencies and percentages. Answers to open-ended questions and additional comments were summarised and presented.
Results
Demographics
A total of 228 responses were received (response rate = 5.12%). More than two-thirds of respondents (n = 164, 71.93%) were men (Table 1). The mean age of respondents was 53.67 ± 12.15 years. The respondents had been in clinical practice for a mean of 23.61 ± 13.02 years, with 192 (84.22%) having at least 10 years of experience. The majority (n = 188, 82.64%) were practice owners.
Respondents’ demographic and clinical experience data (n = 228).
DSO: dental service organisation.
Malocclusions treated early
The majority of respondents (n = 186, 81.58%) reported that the primary reason parents and guardians had sought early treatment for their child was a referral from their general dentist practitioner (GDP) (Table 2). Anterior crossbite was the condition most frequently treated early (n = 226, 99.12%), followed by posterior crossbite (n = 218, 95.61%), while deep impinging bite had the lowest frequency for early treatment (n = 125, 54.82%). The vast majority of respondents undertook initial consultations during the stages of early (n = 105, 46.05%) and mid (n = 100, 43.86%) mixed dentition. Most respondents indicated that they rely on pubertal signs (n = 141, 61.84%) and/or dental age (n = 139, 60.96%) to time the growth modification interventions.
Summary of responses related to timing of early orthodontic treatment.
Additional reported indications of early treatment include impaction/ectopic eruption, patients with cleft lip and/or palate, airway or speech problems, functional shift, severe overjet and traumatic deep bite, habits, skeletal discrepancy and family concerns. Treatment timing also depends on chronological/developmental age, skeletal/dental, early loss of primary dentition, type and severity of malocclusion, stage of growth, compliance levels, sex (earlier in girls), presence of habits or sleep disorders and pubertal growth spurt.
CVMI: cervical vertebrae maturation index.
Most respondents preferred to treat posterior crossbite (n = 117, 51.32%), increased overjet (n = 95, 41.67%), space loss (n = 94, 41.23%), crowding (n = 90, 39.47%) and anterior open bite (n = 85, 37.28%) during the mid-mixed dentition stage (Figure 1, Table 3). According to over half of the participants (n = 125, 54.82%), the presence of an anterior crossbite warranted treatment during early mixed dentition when compared to other malocclusions. Contrarily, most respondents (n = 84, 36.84%) favoured treating deep bites during the permanent dentition stage.
The dental phase during which the participants would likely initiate early orthodontic treatment for different occlusal discrepancies.
The stage of dental development indicated by the respondents to initiate early treatment for various occlusal conditions.
Values are given as n (%).
Preferred treatment approach
In terms of preferred treatment approach, most respondents reported the use of 2×4 fixed appliances (n = 186, 81.58%) and protraction facemask therapy (n = 145, 63.6%) to correct an anterior crossbite (Table 4). For posterior crossbites, 145 (63.59%) respondents showed a preference for rapid palatal expanders (RPEs). Arch length preservation with a lingual or palatal arch was the main treatment modality used to address crowded dentition early (n = 151, 66.23%) and prevent space loss (n = 178, 78.07%). Regarding anterior open bite correction, the majority of respondents (n = 143, 62.72%) indicated the use of other treatment modalities beyond those listed, such as tongue exercises, cribs and habit counselling. When treating cases with increased overjet, most respondents reported the prescription of either sectional fixed appliances (n = 86, 37.72%) or functional appliances (n = 94, 41.23%). Moreover, 143 (62.72%) respondents selected the anterior bite plane as their appliance of choice to correct deep overbites. Herbst appliance (n = 96, 42.11%) and facemask (n = 203, 89.04%) were commonly prescribed for the early correction of Class II and III, respectively. The most popular habit-breaking appliance among respondents was the fixed crib (n = 163, 71.49%).
Summary of responses related to the interventional approaches in early orthodontic treatment.
Other treatment approaches include tongue crib and exercise, speech therapy, habits’ counselling, expansion to relieve crowding and airway issues, myofunctional therapy, Carriere motion appliance, Forsus, E-arches, serial extraction, self-ligating brackets for posterior crossbite correction and miniscrews for molar intrusion.
MARA, mandibular anterior repositioning device.
Outcomes and efficacy of early treatment
Approximately one-third of respondents (n = 74, 32.46%) strongly agreed with the need for a two-phase orthodontic treatment (Table 5). Moreover, 112 (49.12%) respondents reported that 75%–100% of patients can benefit from early treatment. Regarding the likelihood of benefitting from early treatment, anterior crossbite was ranked highest, while deep impinging bite was ranked lowest. More than two-third of respondents (n = 166, 72.81%) believed that 75%–100% of patients would need phase II treatment after early intervention. Finally, over one-third of participants (n = 81, 35.52%) agreed that interceptive treatment is simple and relatively inexpensive compared to fixed orthodontic appliances.
Summary of responses related to outcomes and efficacy of early orthodontic treatment.
In the free-text section, respondents highlighted the benefits of early treatment, including the avoidance of dental trauma and psychological advantages for patients with excessive overjet (3.51%) (Appendix 2). In addition, treatment is beneficial for patients requiring expansion in preparation for alveolar grafts or clefts, as well as for eliminating functional shifts (3.95%) and addressing sleep-disordered breathing and airway issues (2.19%). Regarding treatment approaches, expansion techniques, such as the use of the Haas appliance and other functional appliances, were frequently reported (4.82%).
Discussion
Summary
This cross-sectional survey study provides an overview of early orthodontic measures and modalities adopted by orthodontists in the United States. The findings indicate a widespread endorsement of early orthodontic treatment among respondents who were members of the AAO for various malocclusions, employing a diverse array of appliances. This was attributed to the perceived positive outcomes associated with early intervention. Respondents had been in clinical practice for a mean of 23.61 ± 13.02 years, indicating extensive experience that provides valuable insights into early treatment approaches. This aligns with previous surveys conducted through the AAO Partners in Research program, where respondents predominantly had over 20 years of clinical experience (Abu Arqub et al., 2024b; Logan et al., 2024).
Based on the current study, it is evident that parents/guardians often seek early treatment for their children upon referral from their GDPs and are driven by both aesthetic and functional concerns. The pivotal role of the GDP is recognised in ensuring accurate diagnosis and timely referrals, a responsibility facilitated by being up to date through continuing education courses. However, a previous study found that 85% of Australian GDPs were unaware of their scope of practice regarding early orthodontic treatment, most probably because non-orthodontists cannot provide orthodontic treatment (Currell et al., 2019). The precise number of undiagnosed cases that remain unreferred is unclear. Based on the findings of the current study, initial orthodontic consultations are typically undertaken in the early or mid-mixed dentition. This finding aligns with the AAO recommendation that children should ideally be seen by an orthodontist at the age of 7 years to monitor occlusal development and raise parental awareness of malocclusion (Aldweesh et al., 2022). Similarly, the British Orthodontic Society (BOS, 2024) recommends early referral in cases involving anterior or posterior crossbite with displacement, skeletal problems, asymmetry in tooth eruption, Class III cases, impaction, submergence and severe crowding. However, although early referral is beneficial, there is also a risk of over-referral for conditions that may be better managed with observation until later stages of development.
Generalisability and interpretation
Respondents indicated a preference for addressing anterior crossbite during the early mixed dentition stage. Anterior crossbite is often associated with poor aesthetics, and if left untreated, it may potentially lead to enamel wear, periodontal damage and mobility of the affected teeth, as well as temporomandibular joint dysfunction, and theoretically, an adverse growth influence on the mandible (Borrie and Bearn, 2011). Moreover, anterior crossbite correction is often stable with additional benefits including improvement in lip position and facial balance, and the space provision in the dental arch (Borrie and Bearn, 2011). In the present study, the 2×4 fixed appliance was favoured for early correction of anterior crossbite. However, the latest Cochrane review on Class III malocclusion found moderate evidence supporting the effectiveness of non-surgical orthodontic treatments (such as facemask, reverse Twin Block, orthodontic removable traction appliance, chin cup, tandem traction bow appliance and mandibular headgear) to bring about a substantial improvement in overjet in children aged 5–13 years when treatment started. The review emphasised the need for long-term evaluation to assess the sustained efficacy of these treatments (Owens et al., 2024).
The utilisation of facemask for Class III growth modification was favoured by the majority of respondents. A clinical trial found that using facemask therapy in patients aged 7–9 years obviated the perceived need for orthognathic surgery in 64% of the participants at 6-year follow-up (Mandall et al., 2016). However, for maximum protraction effects, facemask use is best initiated during the eruption of the upper incisors (Arqub et al., 2024a), and when the maxillary sutures are patent (Yüksel et al., 2001). However, long-term stability depends on the amount of mandibular growth occurring after adolescence (Yüksel et al., 2001).
As for Class II malocclusion, classic randomised controlled trials conducted in Florida (King and Brudvik, 2010), North Carolina (Tulloch et al., 2004), and the UK (O’Brien, 2006) have ascertained comparable outcomes in late and early treatment. However, the latter might be prescribed in cases with an increased risk of dental trauma or for children with psychosocial challenges related to their occlusion (Tausche et al., 2004; Thiruvenkatachari et al., 2015). Respondents to the current study favoured the prescription of fixed appliances for Class II correction; this is likely attributed to compliance issues commonly reported with the use of removable appliances (Al-Moghrabi et al., 2017).
Most respondents favoured treating deep overbite in the permanent dentition stage using an anterior bite plane. The anterior bite plane facilitates the eruption of the buccal segment, compensated by available vertical growth and accompanied by the relative intrusion of the incisors in growing children (Ghafari and Macari, 2013). A clinical trial revealed more favourable overbite reduction at puberty in the permanent dentition compared to treatment of deep overbite before puberty in the mixed dentition (Baccetti et al., 2012). Respondents in the present study favoured the fixed crib as a habit-breaking appliance compared to other modalities. However, comparable effects were found using bonded lingual spurs, and fixed and removable cribs in the cessation of habits and improvement of anterior open bite in growing children (Meng et al., 2023). However, long-term data concerning stability of vertical correction, using various modalities, are lacking.
In terms of posterior crossbite correction, early treatment may be indicated when there is an associated occlusal displacement. The majority of respondents preferred addressing posterior crossbite in the mid-mixed dentition, with the RPE being the preferred treatment approach, while removable plates were the least preferred. Similarly, a systematic review evaluating various treatment modalities for the correction of unilateral posterior crossbite in the mixed dentition concluded that the evidence is weak in supporting the efficacy of any specific treatment, including grinding, quad helix appliance, expansion plates or RPE (Petrén et al., 2003). However, the latest Cochrane review found that the quad helix was more efficient than removable plates for treating crossbites in the mixed dentition, with a shorter treatment duration (Ugolini et al., 2021).
Most respondents favoured two-phase orthodontic treatment, with 75%–100% of patients who underwent phase I reportedly requiring phase II treatment. The majority also disagreed with the statement that interceptive treatment is less expensive than fixed appliance therapy. This perspective may stem from the understanding that early treatment does not always eliminate the need for subsequent fixed appliance therapy, particularly in complex malocclusions such as severe Class II or Class III cases. This partially aligns with a previous survey conducted over two decades ago, which aimed to identify optimal treatment timing among orthodontic clinicians in the United States (Yang and Kiyak, 1998). The respondents in their study favoured the mixed dentition stage for addressing some occlusal deviations, particularly for anterior crossbites (early mixed dentition stage), deep overbite and mandibular deficiency (late mixed dentition) (Yang and Kiyak, 1998). Other conditions such as midline diastema and missing teeth were preferred to be treated at later stages (Yang and Kiyak, 1998).
Implications for future research
Future clinical trials assessing the benefits, potential harms and stability of outcomes would be valuable for further refinement of treatment approaches. Such research could provide clearer insights into the long-term effects of various interventions and help identify best practices in orthodontic care. Ultimately, these findings could inform the development of updated clinical guidelines, ensuring that practitioners have the most effective and evidence-based strategies for treating patients. In addition, conducting surveys in different regions would be valuable for assessing variations in orthodontic practices worldwide.
Limitations
A limitation of the current study is that the survey only targeted AAO members in the United States; therefore, the findings cannot be generalised. This is especially important due to the acknowledged differences in prescribing early orthodontic treatment in various regions, resulting from diverse educational and healthcare systems (Fleming and Andrews, 2023). It would be useful for future studies to capture these differences and develop clinical guidelines concerning treatment timing and approaches for different types of malocclusion. Another limitation of the current study included the relatively low response rate, a common challenge in survey-based studies that could give rise to response bias. The response rate could have possibly been enhanced by incentivising and re-notifying the respondents (Short et al., 2015). In addition, the mean age of respondents and length of time in clinical practice was relatively high so the results may not be representative of the younger generation, more recently qualified orthodontists.
Conclusion
Overall, the study highlights the widespread endorsement of early orthodontic treatment for diverse malocclusions among responders from the members of the AAO. The mid-mixed dentition stage was frequently targeted for early orthodontic intervention. Various malocclusions, including posterior and anterior crossbite, increased overjet, crowding, space loss and anterior open bite, are commonly addressed during this phase. Popular treatment approaches include sectional fixed appliances, Herbst appliance, facemask, rapid palatal expanders and anterior bite planes. The majority of respondents support the concept of two-phase orthodontic treatment, with the perceived highest success in correcting anterior and posterior crossbites.
Supplemental Material
sj-docx-1-joo-10.1177_14653125251358832 – Supplemental material for Early orthodontic treatment practices and perceptions: A cross-sectional survey of AAO members
Supplemental material, sj-docx-1-joo-10.1177_14653125251358832 for Early orthodontic treatment practices and perceptions: A cross-sectional survey of AAO members by Monique Nguyen, Dalya Al-Moghrabi, Lauren Tomlinson, Niloufar Azami, Calogero Dolce and Sarah Abu Arqub in Journal of Orthodontics
Supplemental Material
sj-docx-2-joo-10.1177_14653125251358832 – Supplemental material for Early orthodontic treatment practices and perceptions: A cross-sectional survey of AAO members
Supplemental material, sj-docx-2-joo-10.1177_14653125251358832 for Early orthodontic treatment practices and perceptions: A cross-sectional survey of AAO members by Monique Nguyen, Dalya Al-Moghrabi, Lauren Tomlinson, Niloufar Azami, Calogero Dolce and Sarah Abu Arqub in Journal of Orthodontics
Footnotes
Author’s Note
Sarah Abu Arqub is now affiliated to Department of Orthodonitcs, Dental college of Georgia at Augusta University, Augusta, GA, USA.
Declaration of conflicting interests
The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: SA, CD, MN, LT and NA are members of the American Association of Orthodontics.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
Supplementary material
Supplementary material for this article is available online.
References
Supplementary Material
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