Pediatric mainstream clear-aligner early orthodontic orders in Guangdong public tertiary hospitals: service patterns, service-duration tiers and order conversion

Abstract

Background

Early orthodontic assessment is increasingly recognized as part of child oral-health and dentofacial developmental care. Clear-aligner therapy has expanded from adult permanent-dentition treatment to selected mixed-dentition and adolescent indications, but real-world evidence on pediatric clear-aligner service delivery in public hospital settings remains limited. This study examined pediatric mainstream clear-aligner orders in Guangdong, China, focusing on annual service patterns, city-level distribution, service-duration tiers, clinician participation and manufacturer-observed order conversion.

Methods

This retrospective observational real-world service study used de-identified operational order records from public tertiary hospital settings in Guangdong. Eligible records were restricted to commercially manufactured pediatric mainstream clear-aligner orders with one-year, two-year or six-year service-duration categories; no in-house aligners were included. These categories mainly target children approximately 6–13 years of age in late primary, mixed and early permanent dentitions and were treated as administrative service tiers rather than validated clinical severity grades. Order conversion was defined as a non-missing production-scheduling date. Descriptive analyses summarized service-duration tier, year, city, public hospital institution type and anonymized clinician-account participation. A multivariable logistic regression model with city-clustered robust standard errors estimated exploratory associations with conversion.

Results

A total of 4,531 pediatric mainstream clear-aligner orders were submitted, and 3,994 progressed to production scheduling, yielding a crude conversion rate of 88.1%. The one-year, two-year and six-year categories accounted for 2,202, 2,048 and 281 orders, respectively, with conversion rates of 91.9%, 85.2% and 80.1%. By manufacturer-defined service-function positioning, the one-year and two-year categories were not positioned for extraction-including or molar-distalization pediatric workflows and accounted for most submitted and converted orders. A total of 362 anonymized clinician accounts submitted pediatric orders, and 346 had at least one converted pediatric order. Guangzhou and Shenzhen contributed the largest order volumes. Public stomatological hospitals had a higher crude conversion rate than Departments of Stomatology of public general hospitals (91.7% vs. 81.3%). Exploratory adjusted modeling suggested associations with service-duration category and institution type, but these findings were interpreted as service-process signals rather than clinical efficacy or treatment success.

Conclusions

Pediatric mainstream clear-aligner early orthodontic orders showed heterogeneity by year, service-duration tier, city, institution type and clinician-account participation. The findings describe administrative ordering and production-scheduling patterns within a defined public-hospital manufacturer channel and should not be interpreted as evidence of clinical effectiveness, patient benefit, population-level treatment coverage or unmet need. Future research should link verified patient-residence data, official child-population denominators and clinical diagnostic records to estimate population-adjusted utilization and need-service alignment.

Background

Malocclusion in children can affect oral function, oral hygiene, dental and maxillofacial growth, facial esthetics and psychosocial well-being. The 2024 expert consensus on pediatric orthodontic therapies emphasized that childhood malocclusion affects approximately 260 million children in China and that timely intervention may reduce later severity or complexity when diagnosis, timing and staged treatment goals are appropriate [1]. Chinese expert consensus also stresses that early orthodontic treatment should not be equated with indiscriminate early appliance use; clinicians should evaluate growth pattern, environmental factors, oral habits, occlusal development and treatment risk before intervention [1, 2].

Evidence for clear-aligner treatment in growing patients is expanding but remains heterogeneous. A systematic review reported more consistent dentoalveolar effects than skeletal-base changes, and found insufficient evidence that mandibular-advancement clear aligners outperform traditional functional orthopedic appliances for dentoskeletal Class II correction [3]. A recent scoping review of CAT prediction, effectiveness and limitations emphasized that predictability varies by movement type and complexity, with limitations in torque, rotation, overbite control, bodily expansion, refinement needs and occasional hybrid or fixed-appliance conversion in complex cases [4]. These findings support cautious use of CAT in selected pediatric indications rather than universal use across all early malocclusion types.

Available pediatric and adolescent studies suggest selected applications, including mixed-dentition interceptive problems [5], mild-to-moderate maxillary transverse deficiency [6], functional clear-aligner protocols for Class II correction [7, 8], complex mixed-dentition crowding or impacted canine management [9], deep overbite correction with lower-incisor intrusion [10], anterior crossbite in mixed dentition [11], adolescent anterior open bite [12] and maxillary first-molar distalization in mixed or early permanent dentition [13]. However, these clinical studies do not justify using manufacturer-defined service duration as a direct measure of individual diagnosis, severity or treatment outcome.

The Chinese pediatric early-orthodontic consensus identifies 15 manifestations of malocclusion that require early orthodontic treatment assessment or timely intervention across primary, mixed and early permanent dentitions: anterior crossbite in deciduous dentition, anterior crossbite in mixed dentition, deep overjet, deep overbite, open bite, narrow arches, posterior crossbite, scissor bite, crowding, impacted teeth, occlusal interference, ectopic eruption, mandibular retrusion, maxillary deficiency and harmful oral habits [1]. This early-assessment concept is consistent with American Association of Orthodontists guidance, which recommends the first orthodontic check-up no later than age 7 and identifies developing problems such as premature or delayed primary-tooth loss, chewing difficulty, mouth breathing, jaw shifting, cheek biting and facial imbalance as warning signs requiring assessment [14, 15].

Clear-aligner therapy differs biomechanically from fixed appliances. Aligners deliver staged forces through elastic deformation and crown coverage, and predictability varies by movement type, anchorage design, adjunctive attachments, elastics, growth stage and patient adherence [4]. The American Board of Orthodontics Discrepancy Index (ABO-DI) is a conventional case-complexity measure based on measurable clinical and cephalometric entities [16]. The Clear Aligner Treatment Complexity Assessment Tool (CAT-CAT) was developed to appraise clear-aligner difficulty using model analysis, radiographic examinations and clinical examinations [17], and a recent expert consensus further emphasized difficulty grading for clear-aligner therapy [18].

The public-health burden of malocclusion in China is substantial. A national investigation of 25,392 Chinese children reported an overall malocclusion prevalence of 67.82% [19]. A systematic review and meta-analysis of Chinese schoolchildren from 1991 to 2018 also supported a high burden of malocclusion in school-age populations [20]. Regional studies in southern and eastern China have reported high adolescent prevalence: a Jiangxi epidemiological study of 5,387 adolescents aged 12–14 years reported 79.67% [21], and a Shanghai study reported 83.5% [22]. These estimates support the public-health relevance of pediatric orthodontic services, but they should not be used as Guangdong-specific denominators or as evidence that all children with malocclusion require clear-aligner early treatment.

International evidence on CAT utilization is largely survey-based. Studies from mixed-dentition practice settings, Iran, Australia, the United Kingdom and Republic of Ireland, Canada, New Zealand, the United States/Canada and Turkey describe clinician attitudes, preferred indications, training, adjuncts, monitoring and perceived limitations [23–31]. Survey evidence is useful for understanding clinician perception and case selection, whereas operational manufacturer-side order data can describe real-world order progression and service-flow patterns in a large defined channel. These evidence sources are complementary rather than interchangeable.

The present study therefore focused on pediatric mainstream clear-aligner orders in Guangdong public tertiary hospital settings. The objective was to describe annual service patterns, city-level distribution, manufacturer-defined service-duration tiers, anonymized clinician-account participation and order conversion while avoiding unsupported claims about clinical efficacy, true treatment coverage or unmet need.

Methods

Study design and reporting

This was a retrospective observational real-world service study using routinely collected, de-identified operational clear-aligner order data. The manuscript was structured according to STROBE principles for observational studies and RECORD principles for studies using routinely collected health-related data [32, 33].

Data source and study setting

The source file was a de-identified Excel dataset derived from a broader historical real-world clear-aligner order database from public tertiary hospital settings in Guangdong, China. The broader source database contained more than 20,000 public-hospital clear-aligner order records from public stomatological hospitals and Departments of Stomatology of public general hospitals. Private dental clinics, private dental hospitals, community health clinics and primary/community oral-health service settings were not included. The present analysis extracted only eligible pediatric mainstream clear-aligner orders.

All included orders referred to commercially manufactured clear aligners supplied by a single domestic mainstream clear-aligner manufacturer through public-hospital channels. No in-house aligners were included. The manufacturer’s annual report was cited only to contextualize the manufacturer as a listed domestic clear-aligner manufacturer and was not used as an analytical data source. Variables available for analysis included order creation time, design-entry time, production-scheduling time, service-duration category, public hospital institution type, institution city, anonymized clinician account and city-level per-capita GDP. Patient identifiers were not available, and patient-level clinical or demographic variables such as age, sex, residence address, household income, malocclusion diagnosis, ABO-DI score, CAT-CAT score, extraction status, treatment outcome, compliance and adverse events were not available to the investigators in the analytic dataset.

Eligibility criteria and service-duration grouping

Eligible records were restricted to pediatric mainstream clear-aligner categories with one-year, two-year or six-year service duration. In the analytical framework used by this study, these aligners mainly target children approximately 6–13 years of age in late primary, mixed and early permanent dentitions. Other clear-aligner product lines, mainly designed for older adolescents or adults in this analytical framework, were excluded from all analyses.

The one-year, two-year and six-year categories were treated strictly as manufacturer-defined administrative service-duration tiers. They were not treated as validated clinical severity grades, and treatment duration was not assumed to be a validated surrogate for malocclusion severity. According to the manufacturer-defined service-function positioning used in the dataset, one-year and two-year categories were not positioned for extraction-including or molar-distalization pediatric cases, whereas the six-year category could include extraction-including or molar-distalization pediatric cases when clinically selected. Because patient-level diagnoses, extraction status, molar-distalization status, treatment plans, ABO-DI scores and CAT-CAT scores were unavailable, the categories should be interpreted as service-duration groupings rather than direct measurements of individual malocclusion complexity (Table 1).

Table 1.

Manufacturer-defined service-duration tiers and operational definitions

Service-duration tier	Service duration	Typical target population in this dataset	Extraction-including case positioning	Molar-distalization positioning	Interpretation in this study
One-year aligner	1 year	Approximately 6-13-year-old children in late primary, mixed or early permanent dentitions	Not positioned for extraction-including pediatric cases	Not positioned for molar-distalization pediatric cases	Administrative service-duration tier; not a measured clinical severity grade
Two-year aligner	2 years	Approximately 6-13-year-old children in late primary, mixed or early permanent dentitions	Not positioned for extraction-including pediatric cases	Not positioned for molar-distalization pediatric cases	Administrative service-duration tier; not a measured clinical severity grade
Six-year aligner	6 years	Approximately 6-13-year-old children in late primary, mixed or early permanent dentitions	Can include extraction-including pediatric cases when clinically selected	Can include molar-distalization pediatric cases when clinically selected	Administrative service-duration tier; not a measured clinical severity grade

Table 1 describes manufacturer-defined service-function positioning and operational definitions used for this order-level analysis. It does not represent measured patient-level diagnosis, measured ABO-DI score, measured CAT-CAT score, extraction status, molar-distalization status or clinical outcome

Outcomes and analytic flow

The primary order-level outcome was order conversion, defined as a non-missing production-scheduling time. This outcome indicates that the order progressed to production scheduling within the manufacturer-side workflow. It does not represent treatment initiation, treatment completion, appliance wear, patient adherence, clinical effectiveness, patient satisfaction, adverse events or health benefit. Orders without a production-scheduling time were classified as not converted. Workflow outcomes included time from order creation to design entry, time from design entry to production scheduling and time from order creation to production scheduling. Negative workflow intervals were treated as invalid for workflow-time summaries because they were inconsistent with the intended event sequence.

Analytic flow. The broader source database contained more than 20,000 de-identified public-hospital clear-aligner order records from Guangdong. After restriction to eligible pediatric mainstream one-year, two-year and six-year service-duration categories, 4,531 records remained in the analytical sample. Of these, 3,994 had a production-scheduling time and were classified as converted, while 537 lacked a production-scheduling time and were classified as not converted. Patient-level clinical records were not available for linkage or validation.

Malocclusion prevalence context

Malocclusion prevalence was included only as contextual public-health burden. National and regional studies in China report high malocclusion prevalence [19–22]. No official or peer-reviewed Guangdong-specific pediatric malocclusion prevalence dataset was verified for quantitative linkage to the present institution-city order data. Therefore, this study did not calculate prevalence-adjusted treatment coverage or unmet need. This decision was made to avoid fabricating disease denominators or over-extending regional prevalence estimates.

Clinician-account and temporal service-context variables

The analytic dataset included anonymized clinician accounts. These identifiers allowed descriptive counts of clinician participation but did not include clinician age, sex, educational background, professional title, years of practice, specialty training, communication style or clinical decision-making variables. City-onboarding timing was not modeled as a causal exposure because it was derived from the same order records and was partly collinear with calendar year, city and product availability. Temporal analyses were therefore interpreted as ordering patterns rather than changes in disease prevalence or healthcare utilization.

Statistical analysis

Categorical variables were summarized as counts and percentages. Continuous workflow intervals were summarized using medians and interquartile ranges because interval distributions were right-skewed. Service-duration distributions were summarized by year, city and public hospital institution type. Puning was merged with Jieyang for city-level summaries because Puning is administratively under Jieyang. A formal sample-size calculation was not performed because all eligible pediatric mainstream clear-aligner records available in the operational dataset were included.

A multivariable logistic regression model estimated adjusted odds ratios (ORs) for order conversion. Covariates included service-duration category, public hospital institution type, calendar year and standardized city-level per-capita GDP. The one-year aligner and Department of Stomatology of public general hospital were used as reference categories. Robust standard errors were clustered by institution city to account for within-city correlation. Because only nine city clusters were available and patient-, hospital- and clinician-level variables were unavailable, the adjusted model was interpreted as exploratory. No birth-cohort denominator, malocclusion-prevalence denominator, ABO-DI score, CAT-CAT score or patient-level clinical severity denominator was imputed.

Results

Annual service pattern

Pediatric mainstream clear-aligner orders increased over calendar years, with the largest annual volume observed in 2025. The one-year service-duration tier increased sharply in the most recent year, the two-year service-duration tier remained an important administrative category across the study period, and six-year service-duration orders increased after their introduction. These temporal changes should be interpreted as manufacturer-observed public-hospital ordering patterns. They should not be interpreted as changes in malocclusion prevalence, patient preference, healthcare utilization or clinical effectiveness. The annual distribution of pediatric mainstream clear-aligner orders is presented in Table 2.

Table 2.

Annual distribution of pediatric mainstream clear-aligner orders

Year	All orders	Converted	Conversion rate	One-year aligner	Two-year aligner	Six-year aligner
2018	1	1	100.0%	0	1	0
2019	46	41	89.1%	0	46	0
2020	198	173	87.4%	0	196	2
2021	292	248	84.9%	18	266	8
2022	394	336	85.3%	46	337	11
2023	499	430	86.2%	142	349	8
2024	885	811	91.6%	388	422	75
2025	2,216	1,954	88.2%	1,608	431	177

Analytical sample and service-duration distribution

The analytical sample included 4,531 eligible pediatric mainstream clear-aligner orders extracted from the broader public-hospital order database. Overall, 3,994 orders had a non-missing production-scheduling time, corresponding to a crude conversion rate of 88.1%. One-year and two-year aligners accounted for most orders: the one-year aligner contributed 2,202 created orders and 2,024 converted orders, while the two-year aligner contributed 2,048 created orders and 1,745 converted orders. The six-year aligner contributed 281 created orders and 225 converted orders, representing a smaller long-duration pediatric service category.

By manufacturer-defined service-function positioning, the one-year and two-year categories were not positioned for extraction-including or molar-distalization pediatric workflows. These two categories accounted for 4,250 of 4,531 submitted orders (93.8%) and 3,769 of 3,994 converted orders (94.4%). Because patient-level treatment-plan records were unavailable, this finding indicates the distribution of orders across manufacturer-defined service categories rather than verified extraction status or molar movement for each patient. The service-duration conversion and workflow summary is presented in Table 3.

Table 3.

Service-duration conversion and workflow summary

Aligner category	Administrative tier	Created orders	Converted orders	Conversion rate	Median creation-to-production days (IQR)
One-year aligner	One-year service-duration tier	2,202	2,024	91.9%	9.7 (6.5–14.3)
Two-year aligner	Two-year service-duration tier	2,048	1,745	85.2%	11.4 (7.1–17.7)
Six-year aligner	Six-year service-duration tier	281	225	80.1%	11.3 (7.1–18.1)

City-level service pattern

Guangzhou and Shenzhen contributed the largest crude order volumes, indicating that pediatric mainstream clear-aligner services were concentrated in the two largest institution-city markets in this public-hospital dataset. Jiangmen showed a high crude conversion rate, but its denominator was much smaller than Guangzhou or Shenzhen. Smaller cities showed wider variability in crude conversion rates. City-level per-capita GDP was included in the adjusted model to account for macroeconomic differences, but it was not significantly associated with order conversion. Because patient residence and city-specific child-population denominators were not available, these results should be interpreted as institution-city service patterns rather than city-level treatment rates, patient-residence utilization or population coverage. The city-level distribution of pediatric mainstream clear-aligner orders is presented in Table 4.

Table 4.

City-level distribution of pediatric mainstream clear-aligner orders

City	Created orders	Converted	Conversion rate	One-year aligner	Two-year aligner	Six-year aligner
Guangzhou	2,940	2,667	90.7%	1,395	1,390	155
Shenzhen	842	689	81.8%	344	416	82
Jiangmen	269	265	98.5%	252	12	5
Zhongshan	183	129	70.5%	114	52	17
Shantou	121	112	92.6%	43	58	20
Dongguan	91	58	63.7%	29	61	1
Zhuhai	69	59	85.5%	22	46	1
Shanwei	11	11	100.0%	2	9	0
Jieyang/Puning	5	4	80.0%	1	4	0

Public hospital institution type

Across the study period, public stomatological hospitals accounted for 2,995 created orders and 2,745 converted orders, with a crude conversion rate of 91.7%. Departments of Stomatology of public general hospitals accounted for 1,536 created orders and 1,249 converted orders, with a crude conversion rate of 81.3%. Public stomatological hospitals contributed more one-year aligner orders, while Departments of Stomatology of public general hospitals had a relatively larger share of two-year and six-year aligner orders in their service-duration mix. The institution-type distribution of pediatric mainstream clear-aligner orders is presented in Table 5.

Table 5.

Institution-type distribution of pediatric mainstream clear-aligner orders

Institution type	Created orders	Converted	Conversion rate	One-year aligner	Two-year aligner	Six-year aligner
Department of Stomatology of public general hospital	1,536	1,249	81.3%	534	827	175
Public stomatological hospital	2,995	2,745	91.7%	1,668	1,221	106

Adjusted conversion model

In the adjusted logistic regression model with city-clustered robust standard errors, the two-year aligner was associated with lower manufacturer-observed production-scheduling conversion odds than the one-year aligner. The six-year aligner also showed a lower point estimate than the one-year aligner, but its city-clustered confidence interval crossed 1. Public stomatological hospitals had higher adjusted conversion odds than Departments of Stomatology of public general hospitals. Calendar year and city-level per-capita GDP were not statistically significant in this exploratory conversion model. These results should be interpreted as service-process associations and not as evidence of clinical effectiveness or treatment success. The multivariable logistic regression results for order conversion are presented in Table 6.

Table 6.

Multivariable logistic regression for order conversion

Variable	Adjusted OR	95% CI	P-value
Two-year aligner vs. one-year aligner	0.52	0.40–0.69	< 0.001
Six-year aligner vs. one-year aligner	0.47	0.22–1.03	0.058
Public stomatological hospital vs. Department of Stomatology of public general hospital	2.28	1.60–3.24	< 0.001
Calendar year, per one-year increase	0.94	0.82–1.08	0.384
City per-capita GDP, per SD increase	1.03	0.71–1.51	0.865

The model used city-clustered robust standard errors. Because only nine city clusters were available and patient-level variables were unavailable, the adjusted model should be interpreted as exploratory

Anonymized clinician-account service context

The pediatric analytic sample included 4,531 submitted pediatric orders from 362 anonymized clinician accounts; 346 clinician accounts had at least one converted pediatric order, and 21 clinician accounts had converted pediatric orders but no converted orders from other clear-aligner product lines in the source data available for this analysis. Among clinicians with pediatric submissions, the median number of submitted pediatric orders was 5 (mean 12.5; maximum 182). Among clinicians with converted pediatric orders, the median number of converted pediatric orders was 5 (mean 11.5; maximum 161). These clinician-account findings provide service-context only; they cannot be used to infer clinician skill, clinical quality or patient preference because clinician-level characteristics were not available. The anonymized clinician-account service context is summarized in Table 7.

Table 7.

Anonymized clinician-account service context

Descriptor	Value
Pediatric mainstream clear-aligner submitted orders	4,531
Pediatric mainstream clear-aligner converted orders	3,994
Clinician accounts with submitted pediatric orders	362
Clinician accounts with converted pediatric orders	346
Clinician accounts with converted pediatric orders only and no converted orders from other product lines	21
Median submitted pediatric orders per clinician account (mean; max)	5 (12.5; 182)
Median converted pediatric orders per clinician account (mean; max)	5 (11.5; 161)

Clinician identifiers were anonymized. No clinician age, sex, professional title, educational background, years of experience, specialty training, communication style or hospital affiliation name was available in the analytic dataset

Discussion

Principal findings

This real-world study focused on pediatric mainstream clear-aligner orders and excluded other clear-aligner product lines from analysis. Six observed findings are most relevant for a health-services interpretation. First, pediatric mainstream clear-aligner orders increased over calendar years, especially in the most recent period. Second, one-year and two-year service-duration tiers constituted most orders, together accounting for 93.8% of submitted orders and 94.4% of converted orders. Third, the six-year service-duration tier represented a smaller long-duration category. Fourth, Guangzhou and Shenzhen contributed the largest absolute volumes, while crude rates in smaller cities were more variable. Fifth, public stomatological hospitals showed higher crude and adjusted conversion rates than Departments of Stomatology of public general hospitals. Sixth, 362 anonymized clinician accounts submitted pediatric orders and 346 had at least one converted pediatric order, supporting the multiclinician nature of the dataset. These are administrative ordering and production-scheduling patterns, not direct clinical findings.

Clinical context and suitability of CAT in growing patients

The pediatric age range in this study should be interpreted in light of the current evidence base. Clear aligners can be used in selected growing patients for specific dentoalveolar and early orthodontic objectives, including selected expansion, mild-to-moderate crowding or spacing, anterior crossbite, selected open-bite or deep-bite management, selected mandibular-advancement protocols and selected molar distalization [3–13]. However, the evidence base is heterogeneous, and the predictability of tooth movement differs by movement type, treatment mechanics and complexity [4]. The present dataset did not contain malocclusion diagnosis, growth-stage details, appliance-wear adherence, treatment refinements or outcomes. Therefore, these studies provide clinical context only; they cannot be used to infer that all orders in this dataset were clinically appropriate or effective.

Interpretation of service-duration tiers and conversion

This revised manuscript deliberately frames one-year, two-year and six-year aligners as manufacturer-defined service-duration tiers rather than clinical complexity grades. The lower conversion observed for the two-year aligner compared with the one-year aligner should be interpreted as a service-process finding. It may reflect differences in decision complexity, expected service duration, family expectations, treatment burden or functional objectives, but these explanations remain hypotheses rather than measured mechanisms. The six-year aligner group also had a lower conversion point estimate than the one-year aligner, directionally consistent with a longer service-duration tier, but the confidence interval crossed 1 and the subgroup was smaller. These findings should not be interpreted as product efficacy or treatment success. The dataset did not include actual malocclusion type, ABO-DI score, CAT-CAT score, treatment plan details, appliance-wearing compliance, completion status or clinical outcome measures.

The proportion of one-year and two-year category orders is also informative only at the service-design level. Because these categories were not positioned for extraction-including or molar-distalization pediatric cases in the manufacturer-defined service framework, their dominance suggests that most submitted and converted orders belonged to service categories intended for non-extraction and non-molar-distalization pediatric workflows. This should not be restated as a verified patient-level extraction or molar-movement finding because the analytic dataset did not contain treatment-plan records.

Comparison with international CAT utilization literature

Recent international CAT utilization studies provide useful context but differ materially from the present operational dataset. The Iranian specialist-orthodontist survey reported CAT use by 69% of respondents, with use mainly in adults and least in mixed dentition or adolescents. Preferred indications included mild crowding, spacing or diastema, anterior crossbite and mild open bite, while most respondents recognized biomechanical limitations [24]. Surveys from Australia, the United Kingdom and Republic of Ireland, Canada, New Zealand, the United States/Canada and Turkey similarly provide information on clinician preferences, training, aligner systems, adjuncts, monitoring and perceived limitations [25–31]. The mixed-dentition survey by Lynch et al. further supports the view that pediatric aligner use is emerging but selective [23].

Our study is methodologically different from those questionnaire-based studies. The international surveys provide richer clinician-level information but can be affected by response-rate limitations, recall bias and non-response bias. By contrast, the present study used manufacturer-side operational order data, enabling a larger multicity sample of created and production-scheduled orders from a defined public-hospital channel, but with fewer clinical and clinician-level variables. These two approaches are complementary. Surveys are better suited to understanding clinician perception and protocol choice; operational data are better suited to describing observed order progression and service-flow patterns in a large real-world channel.

Institution-type and city-level service patterns

Public stomatological hospitals had higher conversion rates than Departments of Stomatology of public general hospitals. For service planning, an adjusted odds ratio of 2.28 suggests a potentially meaningful difference in manufacturer-observed order progression between institution types within this public-hospital channel. Nevertheless, the mechanism cannot be identified from the current data. The difference may relate to orthodontic workflow organization, specialist concentration, case selection, counseling processes, family expectations or referral pathways, but these remain explanatory hypotheses. The dataset did not include hospital size, hospital ranking, hospital environment, number of orthodontists, patient referral source, patient residence, socioeconomic status, clinician seniority or clinical severity.

City-level service patterns were dominated by Guangzhou and Shenzhen in absolute order volume. This pattern is consistent with the concentration of specialized public dental resources and large metropolitan service capacity in Guangdong, but absolute volume should not be equated with population-level treatment need. In the adjusted conversion model, city-level per-capita GDP was not statistically significant, suggesting that macroeconomic level alone did not explain whether created pediatric mainstream clear-aligner orders converted to production scheduling. In public-health terms, service volume, service intensity and treatment need are different constructs. Service volume can be described from order counts. Service intensity requires valid population denominators and patient-residence data. Treatment need requires malocclusion prevalence, severity and indication criteria.

Clinician-account context

The clinician-account analysis strengthens the service-delivery interpretation but remains descriptive. The pediatric analytic sample was not generated by a small number of isolated providers; 362 anonymized clinician accounts submitted pediatric orders and 346 had at least one converted pediatric order. In addition, 21 clinician accounts had converted pediatric orders but no converted orders from other clear-aligner product lines in the available source data, suggesting that a small subgroup of accounts was focused on pediatric mainstream orders within the observed channel. However, because clinician-level characteristics were removed, we could not examine how clinician experience, education, professional title, communication style or case-selection behavior influenced patient pathway selection or order conversion.

Service-planning and policy implications

The practical implications are limited but relevant. First, public-hospital pediatric clear-aligner pathways should be described and monitored separately from adult clear-aligner pathways because mixed-dentition and early permanent-dentition cases require growth-stage assessment, family counseling and careful compliance management. Second, referral pathways between Departments of Stomatology of public general hospitals and public stomatological hospitals may influence service progression and should be mapped in future studies. Third, workforce planning should focus not only on case volume but also on pediatric orthodontic assessment capacity, diagnostic standardization and training in early-intervention indications. Fourth, future real-world studies should connect operational order data with diagnosis, severity, treatment-stage and outcome data before drawing clinical conclusions about efficacy, appropriateness or unmet need.

Strengths and limitations

A major strength is the relatively large real-world pediatric mainstream clear-aligner sample extracted from a broader database of more than 20,000 historical public-hospital clear-aligner order records from multiple Guangdong cities and two types of public tertiary hospital institutions. Pediatric clear-aligner evidence and clinical-practice literature still relies substantially on small clinical studies or questionnaire surveys, whereas this study used manufacturer-side operational workflow records from a defined public-hospital channel. The dataset included both submitted and non-converted orders, allowing production-scheduling conversion to be described as an observable service-process metric rather than relying only on completed treatments or clinician self-report. The study also reports annual, city-level, institution-type, service-duration and anonymized clinician-account patterns, which helps characterize pediatric clear-aligner service delivery across multiple cities, multiple public-hospital settings and multiple clinicians. In addition, the manuscript explicitly applied STROBE/RECORD-style reporting principles for routinely collected data and deliberately separated manufacturer-defined administrative service-duration tiers from measured clinical complexity. This conservative framing reduces the risk of overinterpreting operational service data as clinical diagnosis, treatment appropriateness or therapeutic effectiveness.

The data-source boundary is also a major limitation. The data reflect a de-identified public-hospital order dataset from a single clear-aligner manufacturer’s Guangdong public-hospital channel. Private dental clinics, private dental hospitals, community health clinics, non-public orthodontic providers, competing clear-aligner manufacturers, other brands and other sales channels were not included. Therefore, the findings cannot represent all pediatric orthodontic services, all clear-aligner providers or the broader Guangdong clear-aligner market. In particular, the dataset cannot determine whether patients in certain cities preferentially sought clear-aligner treatment in private clinics rather than public hospitals.

The dataset was derived from operational records rather than self-reported questionnaires, which reduces recall bias but still means that all observations came from a single measurement source. City-level per-capita GDP was used only as a contextual proxy for the city-market economic environment and should not be interpreted as individual household income, patient affordability or family purchasing power.

Institution city may not equal patient residence city; therefore, city-level findings describe institution-city service patterns rather than patient-residence utilization. National and regional malocclusion prevalence estimates were used only as context because no official Guangdong-specific pediatric prevalence dataset was verified for quantitative linkage. No birth-cohort denominator, malocclusion-prevalence denominator, ABO-DI score, CAT-CAT score or patient-level clinical severity denominator was imputed.

The order dataset lacked patient age, sex, residence, household income, malocclusion diagnosis, ABO-DI score, CAT-CAT score, extraction status, molar-distalization status, treatment plan details, treatment outcome, compliance and adverse-event data. Due to privacy restrictions, the data are not publicly available. The study incorporated ABO-DI, CAT-CAT and pediatric early-orthodontic consensus literature as conceptual frameworks, but avoided imputing unobserved difficulty scores.

For privacy protection, the manufacturer removed specific hospital names and clinician identifiers before data sharing. The analytic dataset included only institution city, institution type and anonymized clinician accounts. It did not include hospital size, hospital environment, hospital ranking, number of orthodontists, clinician age, sex, professional title, educational background, seniority, specialty training or communication style. Therefore, we could not examine how these institutional and clinician-level factors affected patient pathway selection, service preference or order conversion.

Finally, the primary outcome was order conversion, defined as manufacturer-observed production scheduling. This is a service-process metric. It does not represent treatment initiation, active aligner wear, treatment completion, clinical effectiveness, patient satisfaction or patient benefit. Future studies should add treatment start, treatment discontinuation, completion, refinement, adverse events, patient-reported outcomes and clinical outcome measures.

Conclusions

Pediatric mainstream clear-aligner early orthodontic orders in Guangdong public tertiary hospitals showed heterogeneity by year, service-duration tier, city, institution type and anonymized clinician-account participation. One-year and two-year aligners constituted the majority of submitted and converted orders and, by manufacturer-defined service-function positioning, represented categories not positioned for extraction-including or molar-distalization pediatric workflows. Public stomatological hospitals had higher conversion odds than Departments of Stomatology of public general hospitals in exploratory adjusted analysis. The findings should be interpreted as administrative service-delivery signals from a defined public-hospital manufacturer channel rather than evidence of clinical efficacy, disease coverage or unmet need. Verified city-year population denominators, patient-residence information and clinical diagnostic data are needed before population-adjusted service intensity, indication alignment or prevalence-based coverage can be estimated.

Abbreviations

AAO

American Association of Orthodontists

ABO-DI

American Board of Orthodontics Discrepancy Index

CAT

Clear aligner therapy

CAT-CAT

Clear Aligner Treatment Complexity Assessment Tool

CI

Confidence interval

GDP

Gross domestic product

IQR

Interquartile range

OR

Odds ratio

RECORD

REporting of studies Conducted using Observational Routinely-collected health Data

STROBE

Strengthening the Reporting of Observational Studies in Epidemiology

Authors’ contributions

WQC was responsible for conceptualization, data curation and drafting the original manuscript. LH performed statistical analysis, interpreted the results and critically revised the manuscript. YW assisted in data collection and preliminary data processing. All authors have read and approved the final manuscript.

Funding

This work was supported by the Guangdong Health Economics Society 2026 Annual Research Project (General Program) (Grant number: 2026-WJMF-103). The funder had no role in study design, data collection, analysis and interpretation of data, or manuscript writing.

Data availability

The de-identified order-level data analyzed during the current study are not publicly available because they are subject to institutional and data-use restrictions. The present analytic dataset was extracted from a broader historical real-world database containing more than 20,000 public-hospital clear-aligner order records from Guangdong, including public stomatological hospitals and Departments of Stomatology of public general hospitals. Before analysis, records were de-identified and privacy-protective data minimization was applied; patient identifiers and patient-level variables such as age, sex and malocclusion type were not available to the investigators in the analytic dataset. Data may be available from the corresponding author on reasonable request and with permission of the data-holding institution.

Declarations

Ethics approval and consent to participate

The study protocol and data-use plan were submitted to the Medical Ethics Committee (Institutional Review Board) of Sun Yat-sen Memorial Hospital, Sun Yat-sen University for ethical determination. The committee determined that this retrospective study was deemed exempt from ethics approval/full ethics review (Exemption/Waiver Reference: SYSEC2-2026-BA-1025), and the requirement for informed consent to participate was waived by the same committee. This determination was based on the use of only de-identified, order-level operational data from routine public-hospital clear-aligner records; the study did not involve direct patient contact, interventions, human biological materials, clinical photographs, identifiable or re-identifiable personal data, patient-level clinical records or clinical outcome data.

Consent for publication

Not applicable. This manuscript does not contain identifiable individual person’s data, clinical photographs, images, videos or case details.

Competing interests

The authors declare no competing interests.