Oral Health, Dento-facial Condition and OHRQoL in Subjects With Mowat-Wilson Syndrome: an Epidemiologic Study.

Dental caries will be measured as follows:

• frequency of individuals with dental caries
• distribution of patients' dental caries experience according to the individual DMFT index score (ranging from 0 to 28, where zero is equivalent to "no dental caries experience" and 28 that all teeth have been affected)
• localization (type of tooth; permanent/decidous teeth) and severity of dental caries according to the ICDAS index (ranging from 0 to 6, where zero is equivalent to "sound tooth" and 6 to "extensive cavity with visible dentin")

Facial soft tissue characteristics will be measured by 2D and 3D analysis performed on frontal/lateral photographs of the face and 3D face scanning, respectively.

Extraoral facial photographs will be used for 2D facial morphometric analysis, both frontal and profile views, using OrthoTP® software (Microlab, Italy).

3D facial morphometric analysis will be performed on the 3D reconstructions of the subjects' facial scans using VAM software (Canfield Scientific, Inc., Parsippany, NJ, USA).

The reference landmarks and planes for both 2D and 3D facial morphometric analyses were selected according to international criteria and previously validated protocols that have also been applied in the study of subjects with facial dysmorphisms.

The values obtained will be compared with reference values reported in the literature for the general population matched for age and sex.

Dento-skeletal characteristics will be measured by cephalometric analysis performed on lateral skull radiographs of patients, if previously performed and provided by the parents/guardians.

Cephalometric tracings and measures will be performed using OrthoTP® software (Microlab, Italy).

The cephalometric analysis method that will be adopted is that of the Milan School of Orthodontics, which includes several analyses commonly used in orthodontics and internationally validated.

Molar and canine Angle's dental arch relationships, frequency and degree of dental crowding/spacing, dental arch widths (intercanine, interpremolar, and intermolar widths) and depth will be assessed on patient's intraoral digital scans using VAM software (Canfield Scientific, Inc., Parsippany, NJ, USA).

Frequency and type of dental anomalies (missing and/or suvrannumerary tooth; micro/macrodontia; tooth inclusion; tooth displacement; alterations in tooth morphology) will be assessed during the dental examination and on dental radiographs of subjects (panoramic dental x-ray, dental computer tomography) if provided by the parents/guardians

Mean and distribution of the WHO Plaque Index (PI) will be calculated. PI score can range from 0 to 3 (where 0 is "absence of dental plaque" and 3 is "abundant and visibile dental plaque").

Frequency, type and localization of DDEs will be assessed using the DDE index. The DDE index classifies enamel defects according to their clinical appearance. It categorizes defects into three main types: demarcated opacities, diffuse opacities, and enamel hypoplasia, and also allows the recording of combinations of these defects. The index records the type, distribution, and extent of the defect on each tooth surface, enabling consistent documentation and comparison of enamel developmental defects in clinical and epidemiological study.

When the phenotypic appearance will suggest specific alterations consistent with molar-incisor hypomineralization (MIH) or dental fluorosis, specific indices will be used to assess the severity of the lesions (MIH and Dean indexes).

The Community Periodontal Index (CPI) will be used to assess in the 6 sextants of the mouth the parodontal status. The CPI ranges from 0 to 4, where zero stands for "healthy gingiva" and 4 for "deep pocket of 6 mm or more".

Frequency, type (e.g. abscess, leukoplakia, ulcer, oral candidiasis, etc...), and localization (vermilion borderof the lips, commisure of lips, lips, buccal mucosa, floor of mouth, tongue, palate, gum) of oral mucosal lesion will be assessed.

Frequency of convex and concave facial profile, brachicephalic (short-headed) and dolicocephalic (long-headed) craniofacial shape, decreased and increased lower third of the face, and mandibular and facial asymmetry will be assessed.

The frequency of Class I, Class II, Class III, deepbite, openibite, crossbite, and scissorbite malocclusions, increased and/or decreased overjet and overbite, dental crowding, and spacing will be assessed.

Frequency and type of oral habits/oral dysfunctions (e.g. oral breathing, tongue thrust, non-sucking habits, sleep apnoea, bruxism, etc...), tonsillar hypertrophy (Mallampati index), soft palate position (Friedman index), and temporomandibular disorders (TMD) will be assessed.

Oral Health-Related Quality of Life will be assessed using standardized questionnaires: one for subjects up to 17 years of age (P-CPQ Questionnaire) and another for subjects aged 18 years and older (OHIP-14 Questionnaire).

Correlation between genotype and phenotype will be investigated by analyzing the association between the dental, occlusal, and facial characteristics observed and the three main genetic variants of mutation of the ZEB2 gene (complete deletion; absence of protein; defective protein) through Chi-squared and Fisher's exact tests.