Table 1 Summary of articles that met final inclusion criteria

Type of Study

Prospective study

Prospective study

In-vitro study

Cross-sectional

Cross-sectional

Human Subjects or Material

Human subjects

Human subjects

Human autopsy material

Human Subjects

Human subject

Study Objective(s)

Assess the midpalatal suture density via lowdose computed tomography (CT) prior to RME (T0), at the end of active RME (T1), and following a 6 month retention period (T2).

Evaluate the efficacy of ultrasonography (US) to generate a qualitative assessment of ossification post-SARME.

Quantification of sutural morphology via micro-CT and its association with age.

To validate and present a novel classification system for the individual assessment of midpalatal suture morphology using CBCT.

Evaluate the correlation of fractal patterning to ossification of the palatal suture via CBCT evaluation and determine whether fractal analysis of the midpalatal suture can be used to assess the maturation of the suture.

# of Subjects and Inclusion Criteria (if applicable)

17 patients, 7 male, 10 female, mean age of 11.2 years old, range of 8–14 years old.

Inclusion criteria: patients with constricted maxillary arches with or without unilateral or bilateral posterior crossbite, and within cervical vertebral maturation (CS1-CS3)

3 patients, bilateral transverse maxillary deficiencies requiring SARME. Age, sex and developmental characteristics of subjects not given.

28 human-palate specimens, (11 female, 17 male) aged 14–71. The palatal specimens were categorized by the donor’s age into age groups (< 25 years, 25 years to <30 years, ≥ 30 years).

140 subjects (86 female, 56 male), age range from 5.6 to 58.3 years old,

Inclusion criteria: patients who are undergoing initial records for orthodontic treatment and who have received no previous orthodontic treatment.

131 subjects, (69 men and 62 women), mean age

mean age of 24.1 ± 5.9 years

(male subjects 23.1 ± 5.8 years, female subjects 25.2 ± 5.9 years)

Age range of18.1–53.4 years old.

No specific inclusion criteria noted

Study’s Expansion Modality, Expansion protocol, Average amount of Expansion (mm)

Modality:

butterfly palatal expander

Protocol: standard protocol – activated

twice per day (0.25 mm per turn) for 14 days. Retention period of 6 months than appliance removed.

Amount of expansion:

7 mm in all subjects

Modality:

SARME (tooth borne Hyrax).

Protocol:

0.8–0.9 mm expansion/day in two daily activation steps until desired expansion achieved, ~14 days. Retention period of 6 months, then hyrax removed.

Amount of expansion:

not specified but based on clinical needs of patient.

Not applicable, no expansion performed.

Not applicable, no expansion performed.

Not applicable, no expansion performed

Imaging Modality

Multi-slice low-dose Computed tomography (brand information not given).

Standardized axial CT images parallel

to the palatal plane and passing through the furcation of maxillary right first molar, scans acquired and magnified (3×) with Light-Speed 16 software (General Electric Medical System, Milwaukee, WI).

Color-coded Ultrasonography duplex scanner (Aplio 80, Toshiba Tokyo, Japan) with 7.5-MHz linear-array transducer

Scanco Micro-CT 40 (Scanco

Medical, Bassersdorf, Switzerland)

70 kV, 114 μA. Isotropic voxel size

37 μm.

Maximum scanning time of 200 min/specimen. Data analyzed using V4.4A software (Scanco Medical, Bassersdorf, Switzerland).

3D reconstruction via AMIRA 3.00 software m(TGS, Mercury Computer Systems, San Diego, CA).

Bone volume and quantification via Image Tool 3.00 software (UTHSCSA, San Antonio, TX),

iCAT cone-beam 3-dimensional imaging system (Imaging Sciences International, Hatfield, PA).

11 cm Minimum FOV. Scantime from 8.9 to 20 s resolution of 0.25 to 0.30 mm.

Image analysis using Invivo5

(Anatomage, San Jose, CA). A standardized protocol to isolate axial maxillary cross-sections of the palate was presented.

Cone Beam Computed Tomography (CBCT) (Zenith 3D; Vatech Co., Gveonggi-do, Korea) Field of view 20 × 19 cm; voltage 90 kVp; current 4.0 mA; scan time 24 s). Images were assessed using CT software (Ez3D 2009; Vatech Co.),

Region(s) Investigated

Midpalatal suture and maxilla.

4 regions of interest (ROIs);

1. Anterior sutural ROI (AS ROI): located on the

suture 5 mm anterior to nasopalatine

2. Posterior sutural ROI (PS ROI): on suture 5 mm posterior to the nasopalatine

duct

3. Anterior bony ROI (AB ROI): control ROI on

maxillary bone 3 mm to the right of laterally AS ROI

4. Posterior bony ROI (PB ROI): control ROI on maxillary bone

3 mm right of PS ROI

Midpalatal suture

Midpalatal suture

axial central cross-sectional slices generated and used for assessment of the midpalatal suture

axial central cross-sectional slices generated and used for assessment of the midpalatal suture.

A long and narrow region of interest within the final axial slice highlighting only the suture was considered for fractal analysis, such that the incisive canal was not incorporated, but rather the ROI extended from posterior to the incisive canal to just anterior to the posterior nasal spine.

Method of Measurements (units)

1 trained and blinded operator (R.L.) calculated bone density values in Hounsfield units (HU). RL performed measurements and repeated all measurements 1 month later. Bone density changes from T0 through T2 at AS ROI and PS ROI contrasted with the Friedman repeated measures ANOVA on ranks and Tukey post-hoc test (SigmaStat 3.5, Systat Software, Point Richmond, CA).

Ultrasonography findings rated via a semi-quantitative bone fill score (0–3). 0 = complete through-transmission of the ultrasound waves, clear gap margins, and no echogenic material;

1 = partial through-transmission of the ultrasound waves, identifiable gap margins, and less than 50% echogenic material; 2 = partial through-transmission of the ultrasound waves, partially obscured gap margins, and greater than 50% echogenic material; 3 = no through transmission

of the ultrasound waves, invisible gap margins, and 100% echogenic material.

Scores were not supported by histology or CT.

Quantification of 3D Suture Morphology in frontal plane measured: calculated

Obliteration index [%], and mean obliteration index [%].

Quantification of 3D Suture Morphology in Axial plane: measured suture length [μm]: linear sutural distance [μm]: interdigitation index;

Definition of the proposed palatal suture maturational stages (A-E)

determined by two operators.

The definition

of each palatal suture maturational stage derived from the histological appearance of suture described in previous histologic studies.

1 principal investigator trained in the Angelieri et al. [3] method categorized the midpalatal sutures of the patients, and the findings were considered the “ground truth” not “gold standard”. Images were reclassified 2 days later two other operators classified 30 images to determine interexaminer reliability.

For Fractal analysis, image software (Photoshop CS6 Extended; Adobe Systems, San Jose, CA) was utilized to perform Gaussian blurring and subtract this blurred image from the original, followed by skeletonizing of the binary image, and utilizing the box counting method to determine the fractal dimension.

Weighted kappa coefficient was calculated to determine inter- and intra-examiner reliability using MedCalc version 12.3.0 (MedCalc Software, Oostende, Belgium).

Fractal dimension at each maturation stage determined by Scheffe’s ANOVA test.

Spearman’s correlation coefficient was calculated to determine the correlation between the fractal analysis and maturation stage.

Utilized IBM SPSS Statistics version 21.0 software (IBM Co., Armonk, NY)

P < 0.05 was considered statistically significant.

Measurement time points

Three time points;

Before RME (T0), at the end of RME (T1), and after the 6 month retention period

5 time points;

after RME, at 2and 4 months during the expansion period, 6 months later where appliance removed and 2 months post appliance removal.

Note opening of midpalatal suture confirmed by plain radiograph after active expansion.

One time point evaluated

Single time point evaluated prior to RME.

Palatal maturational stage reclassified 2 days later for each patient.

Single time point

Palatal maturational stage reclassified 2 days later for each patient.) .