Assessment of Oral Health-Related Quality of Life in Preschool-Aged Children in Alto Alentejo

Oral Health-Related Quality of Life in a Preschool Population of Alto Alentejo

The observational study aims to improve understanding of Oral Health-Related Quality of Life (OHRQoL) among preschool children in the District of Portalegre, Portugal, by examining the roles of sociodemographic, behavioral, and parental psychosocial factors, as well as the child's oral health status.

The study seeks to answer the following main research question: How do sociodemographic, behavioural, parental psychosocial factors, and the child's oral health status influence the Oral Health-Related Quality of Life (OHRQoL) of preschool children in the District of Portalegre?

Study Overview

• Status: Completed
• Conditions: Gingivitis; Malocclusion; Early Childhood Caries (ECC); Oral Health Related Quality of Life (OHRQoL); Traumatic Dental Injuries

Detailed Description

This observational, analytical, and cross-sectional study aims to deepen understanding of the factors associated with Oral Health-Related Quality of Life (OHRQoL) among preschool children in the Portalegre District.

For participant selection, a probabilistic, multi-stage sampling process, stratified by type of preschool (public or private) and by municipality, was used. The final sample comprises 33 preschools, including 22 public and 11 private.

Data collection comprises two complementary components: a questionnaire completed by parents or caregivers and an intraoral examination for each participating child. The questionnaire comprises seven sections with multiple-choice and open-ended items. It collects information on the child's general health, access to oral healthcare, child and caregiver behaviors, OHRQoL, parental beliefs and attitudes regarding oral health, and sociodemographic characteristics. Distribution is carried out by educators and assistants from the institutions, ensuring delivery to parents or caregivers.

The intraoral examination collected data on oral hygiene, gingival health, the presence of dental caries, malocclusion, and traumatic dental lesions. All records were documented on a standardised form developed for the study. Examinations were carried out in a schoolroom with good natural and artificial lighting, using existing furniture. All infection control and cross-contamination prevention measures were implemented, including the use of disposable gloves and masks, as well as sterilized instruments.

The instruments used included a LED headlight, a flat intraoral mirror, a millimetre ruler, and a CPI (Community Periodontal Index) periodontal probe, in accordance with World Health Organization specifications, with a 0.5 mm ball tip.

The examination followed a standardized sequence: assessment of oral hygiene status, recording of gingival health, toothbrushing with a disposable toothbrush, drying the teeth with gauze, and subsequent evaluation of dental caries, malocclusion, and traumatic dental injuries.

• Study Type: Observational
• Enrollment (Actual): 454

Contacts and Locations

Study Locations

• Portugal
  • Lisbon, Portugal
    • Faculty of Dental Medicine, University of Lisbon

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

Preschool-aged children attending schools in the district of Portalegre

Description

Inclusion Criteria:

• All children who attended the selected classrooms were included in the study and who:

  • Were between 3 and 5 years of age at the time of the observation;
  • Had informed consent provided by their parents or legal guardians;
  • Assented to participate in the study

Exclusion Criteria:

-

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oral Health-Related Quality of Life	The OHRQoL of preschool children will be assessed using the Early Childhood Oral Health Impact Scale (ECOHIS), included in the parent questionnaire. ECOHIS has 13 items: 9 evaluating the impact of oral problems on the child (Child ECOHIS) and 4 evaluating the impact on the family (Family ECOHIS). The child subscale includes four domains (symptoms, function, psychology, and social interaction), while the family subscale includes parental distress and family function. Items use a Likert scale from 0 ("Never") to 4 ("Very often"), with a "Don't know" option treated as missing. Participants with ≥2 "Don't know" responses in the child subscale or ≥1 in the family subscale will be excluded. The total ECOHIS score ranges from 0-52, with child and family scores ranging from 0-32 and 0-16. Higher scores indicate a more negative impact. Assessed at the moment when parents complete the questionnaire.	Baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Level of Oral Hygiene	Oral hygiene was assessed using the soft debris component of the Simplified Oral Hygiene Index (OHI-S), following the criteria proposed by Rodrigues et al. For the primary dentition, the buccal surfaces of teeth 54, 61, and 82 and the lingual surface of tooth 75 were examined with a periodontal probe aligned parallel to the long axis of the tooth. If any of the indicated teeth were missing, the closest distal tooth was examined; if this tooth was also absent, the closest mesial tooth was assessed. Each tooth was assigned an integer score from 0 to 3, and the participant's final score was the mean of the values obtained. Assessed during the intraoral examination.	Baseline
Gingival health	Gingival health was quantified using the ORI (Oral Rating Index), an oral classification index, following the criteria proposed by Kawamura et al. The ORI was based on the examination of four areas: the buccal surfaces of the maxillary anterior teeth, the buccal surfaces of the mandibular anterior teeth, the palatal surfaces of the right maxillary molars, and the lingual surfaces of the right mandibular molars. To determine each individual's ORI level, observable gingival characteristics and the accumulation of calculus and dental plaque were assessed, after which the individual was classified on an ordinal scale. The index was recorded without manual instruments, under natural light, and the decision was made within approximately 10 seconds. In cases of uncertainty, the examiner assigned the lowest score as the representative value for the individual. Assessed during the intraoral examination.	Baseline
Presence of caries	For the diagnosis of dental caries, the procedures and criteria of ICDAS II were followed. The protocol described by this system recommended tooth brushing and drying prior to caries detection; therefore, the teeth were brushed with a disposable toothbrush and then dried with gauze. The system used two digits to record each tooth or surface: the first digit referred to restorations and sealants, and the second to the dental caries diagnosis. In this study, recording was performed per tooth, corresponding to the worst condition observed among its surfaces. In the ICDAS II system, codes 1 and 2 record early non-cavitated caries. However, because data collection occurred in kindergarten settings without the possibility of drying teeth with compressed air, code 1 for smooth-surface lesions could not be used. As anticipated in ICDAS II guidelines for epidemiological studies, codes 1 and 2 were therefore combined and recorded as "A" in this study. Assessed during the intraoral examination.	Baseline
Presence of malocclusion	The criteria for assessing malocclusion followed Bjork, Zhou, and Grippaudo. Malocclusion was classified into three groups: (1) occlusal anomalies (anterior crossbite, edge to edge bite, increased overjet, anterior open bite, deep bite, posterior crossbite, scissor bite); (2) space anomalies (crowding); and (3) dentition anomalies (supernumerary teeth, agenesis, malformations). Anterior crossbite, edge to edge bite, increased overjet, anterior open bite, and deep bite were determined using horizontal and vertical overlap measurements. Horizontal overlap was recorded as the greatest distance between maxillary and mandibular incisors parallel to the occlusal plane; vertical overlap was the greatest distance between their incisal edges. Assessed during the intraoral examination.	Baseline
Presence of dental trauma	The criteria used to diagnose traumatic dental injuries were based on WHO recommendations. Teeth affected by dental trauma were coded as follows: 0 - No signs of injury; 1 - Treated injury; 2 - Enamel fracture only; 3 - Enamel and dentine fracture; 4 - Pulp involvement; 5 - Tooth loss due to trauma; 6 - Other damage; 9 - Tooth excluded Assessed during the intraoral examination.	Baseline

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Psychosocial variables - Parental attitudes towards dental decay	The scale is composed of variables that correspond to factors included in the Parents' Beliefs and Attitudes Questionnaire. This scale assesses parents' beliefs and attitudes regarding the prevention of ECC, including perceived severity, perceived controllability, and external control. All items use the same response format: a 5-point Likert scale ('strongly agree', 'agree', 'neither agree nor disagree', 'disagree', 'strongly disagree'), scored from 1 to 5. Each variable score corresponds to the mean of the items within its respective factor, resulting in values ranging from 1 to 5. Lower scores indicate less positive beliefs and attitudes, whereas higher scores indicate more positive beliefs and attitudes. Assessment is performed at the moment when parents complete the questionnaire.	Baseline
Psychosocial variables - Parental attitudes towards toothbrushing behaviour	The scale is composed of variables that correspond to factors included in the Parents' Beliefs and Attitudes Questionnaire. This scale assesses beliefs and attitudes related to the child's toothbrushing and includes two variables: the importance and intention of brushing the child's teeth, and parents' self-efficacy regarding the child's toothbrushing. All items use the same response format: a 5-point Likert scale ('strongly agree', 'agree', 'neither agree nor disagree', 'disagree', 'strongly disagree'), scored from 1 to 5. Each variable score corresponds to the mean of the items within its respective factor, resulting in values ranging from 1 to 5. Lower scores indicate less positive beliefs and attitudes, whereas higher scores indicate more positive beliefs and attitudes. Assessment is performed at the moment when parents complete the questionnaire.	Baseline
Psychosocial variables - Parental attitudes towards child sugar snacking	The scale is composed of variables that correspond to factors included in the Parents' Beliefs and Attitudes Questionnaire. The scale of parents' beliefs and attitudes regarding the control of cariogenic diet includes the following variables: the importance and intention of controlling cariogenic food intake, and parents' self-efficacy related to the control of cariogenic diet. All items use the same response format: a 5-point Likert scale ('strongly agree', 'agree', 'neither agree nor disagree', 'disagree', 'strongly disagree'), scored from 1 to 5. Each variable score corresponds to the mean of the items within its respective factor, resulting in values ranging from 1 to 5. Lower scores indicate less positive beliefs and attitudes, whereas higher scores indicate more positive beliefs and attitudes. Assessment is performed at the moment when parents complete the questionnaire.	Baseline
Variables related to the habits and behaviors of the mother/father/caregiver	This group of variables gathers information on parents' behavior regarding access to oral health care and toothbrushing, namely: frequency of toothbrushing, dental attendance, and frequency of dental visits. Assessed at the moment when parents complete the questionnaire.	Baseline
Variables related to the child's behaviors	This group of variables includes those related to the child's oral hygiene, eating behaviors, and sucking habits: frequency of toothbrushing, night-time toothbrushing, use of fluoridated toothpaste, adult supervision during toothbrushing, consumption of foods and/or drinks after night-time brushing, foods and/or drinks consumed after night-time brushing, frequency of consumption of cariogenic foods between main meals, frequency of fruit and/or vegetable consumption, pacifier use and thumb sucking. Assessed at the moment when parents complete the questionnaire.	Baseline
Variables related to access to oral health care	This group of variables collects information on the child's use of oral health care services: dental attendance, frequency of dental visits, information received about the child's oral health care and source of information about the child's oral health care. Assessed at the moment when parents complete the questionnaire.	Baseline
Variables related to general health	This group of variables refers to information on the child's general health status and the importance attributed to the child's general and oral health: classification of the child's general health, classification of the child's oral health status, importance of oral health for the child's general health, presence of a relevant health problem or disease and health problem or disease. Assessed at the moment when parents complete the questionnaire.	Baseline
Sociodemographic variables	This group of variables refers to the collection of social, economic, and demographic data from the study participants: sex, age, type of kindergarten, number of people in the household, child's cohabitants, child's nationality, parents' nationality and mother's educational level. Assessed at the moment when parents complete the questionnaire.	Baseline

Collaborators and Investigators

• Sponsor: University of Lisbon
• Collaborators: Universidade Nova de Lisboa

Study record dates

Study Major Dates

• Study Start (Actual): April 11, 2025
• Primary Completion (Actual): March 20, 2026
• Study Completion (Actual): March 20, 2026

Study Registration Dates

• First Submitted: May 31, 2026
• First Submitted That Met QC Criteria: June 10, 2026
• First Posted (Actual): June 15, 2026

Study Record Updates

• Last Update Posted (Actual): June 15, 2026
• Last Update Submitted That Met QC Criteria: June 10, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: oral health related qualiry of life in preschool children
• Additional Relevant MeSH Terms: Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Tooth Diseases; Infections; Gingival Diseases; Malocclusion; Gingivitis
• Other Study ID Numbers: CE-FMDUL202519

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No