Maturation stages of the sutures in the median palatine evaluated with cone-beam computed tomography

Introduction

This study aimed to evaluate the influence of age, sex, and facial growth patterns on the maturation stage of midpalatal sutures.

Methods

We selected 90 total skull cone-beam computed tomography scans and divided them into the following 3 groups: brachyfacial (n = 30), mesofacial (n = 30), and dolichofacial (n = 30). These groups were determined using Ricketts VERT 3-dimensional cephalometric analysis. All patients were aged ≥18 years and were divided into those aged ≥30 years and >30 years. The maturational stage of the median palatine sutures was determined by evaluating the central transverse axial dimension in the maxillary-mandibular palate. Maturational stages were classified as A, B, C, D, and E.

Results

Of the 90 images reviewed, 55 (61.1%) were female patients, and 35 were male patients (38.9%). The age of patients ranged from 18 to 59 years, with 55 patients aged <30 years (61.1%) and 35 aged ≥30 years (38.9%). Regarding the maturational stages, 3.3% of brachyfacial, 6.7% of mesiofacial, and 16.7% of dolichofacial subjects ( P = 0.032) were classified as stages B and C.

Conclusions

The patients’ facial patterns were found to be a significant signal for the maturation stage of midpalatal sutures. Adult dolichofacial patients are the most likely to have stage B and C.

Highlights

  • Rapid maxillary expansion was compared with skeletal anchorage vs surgically assisted in adults.

  • Facial growth patterns on the maturation stages of the midpalatal suture were evaluated.

  • Age did not prove to be a significant sign for the internship.

  • Dolichofacial adults are more likely to have stages B and C of maturation.

Rapid maxillary expansion (RME), also known as palatal expansion, has been widely used in orthodontics since 1860 to increase the jaw width. This treatment is beneficial for increasing the transverse dimensions of the jaw in patients with a narrow palate, can help correct unilateral or bilateral posterior crossbite, and can assist in functions such as breathing.

Orthodontists can use a palatal breaker, Hyrax or Haas, to perform rapid expansion. Usually, these devices are attached to the teeth along the patient’s palate. A breaker device divides the center of the palate, and force is applied so that the 2 halves are separated and the central screw is activated. The sutures are also separated and completely fused, which results in arch expansion. This can be observed through the central diastema between the central incisors. ,

As this treatment is nonsurgical, it is usually recommended for patients who require corrections to their transverse jaw. In adult patients, the sutures are more likely to be completely fused, and therefore, surgical separation is usually required. Surgically assisted palatal expansion is performed under general anesthesia and can be challenging because of a high number of patients being reluctant to undergo the procedure. , ,

Skeletal anchorage using mini-implants can be useful in adults who present with suture maturation stages B and C. These implants allow expanders to be fixed to the palate instead of the teeth. This technique, known as the miniscrew-assisted rapid palatal expander, achieves excellent results. The treatment time and activation intervals are similar to those of a conventional disjunction. The tooth inclination and gingival recession rates are lower, and as the treatment is less invasive, it is considered optimal for adult patients who do not wish to undergo surgery. ,

It is important to understand suture biology and the effect of different age groups and maturation stages on orthodontic, orthopedic, and surgical procedures. Sutures respond to osteogenic stimuli. In the osteogenic process, suture growth and bone remodeling are similar to that of the periosteal bone surfaces, and the adjacent tissue requirements are provided for by external stimuli known as demands functional.

After analyzing the skeletal age of palatine sutures in 186 human skulls, researchers identified their ossification sequence. This sequence starts in the incisive suture, followed by the posterior segment transverse palatine suture and the middle segment of the suture. In this study, maturation of the suture was considered a limiting factor for RME. ,

The treatment modality for maxillary expansion in older patients has historically been a difficult decision. The choice between conventional RME with skeletal or surgically assisted anchoring depends on an patient assessment of suture maturation. Some authors believe that imaging obtained with cone-beam computed tomography (CBCT) could be a useful resource to support decision-making. Therefore, they conducted a study to classify the maturation of the suture, establishing the stages in which the RME skeletal anchorage would be indicated. The classifications ranged from A to E. The fusion of the palatine (stage D) and jaw (stage E) portions of the suture indicated that skeletally anchored RME was contraindicated, and patients can be more effectively treated by surgically assisted palatal expansion. , ,

Recent studies have shown that various facial structures present anatomic variations resulting from a patient’s facial growth pattern. For example, the morphology of the mandibular canal can vary more significantly in brachyfacial or dolichofacial patients than in mesofacial patients, who have more balanced muscles, masticatory function, and facial thirds. ,

In this context, although sutures are broadly studied anatomic structures, few studies have evaluated their maturation in adults through CBCT. Therefore, the objective of this study was to evaluate the maturational stages of sutures in adults using CBCT and correlate them with different facial growth patterns.

Material and methods

This observational retrospective study was approved by the Research Ethics Committee of Brazil (CAAE no. 01617318.0.0000.5374, resolution no. 196/96).

A total of 258 scans taken between January 2015 and May 2019 were reviewed. Of them, 90 CBCT examinations were selected. The following exclusion criteria were used: patients with poor bone formation, lesions in the region of the suture, history of trauma or surgical procedures, presence of impacted teeth, or poor-quality images for viewing the suture. The sample size of 90 participants resulted in a test power of 0.80 (β = 0.20) for a significance level of 0.05 (α = 0.05) and effect size w = 0.39, using the variables of facial growth and maturation stage as standards and calculated with the G∗Power software (Version 8.4.31; Franz Faul University, Kiel, Germany).

The sample consisted of both male and female patients aged 18 years or older. They were divided into the following 3 groups according to their facial growth pattern: brachyfacials (n = 30), mesofacials (n = 30), and dolichofacials (n = 30). Furthermore, 2 subgroups were determined according to age, those aged less than under 30 and over or equal to 30 years old. The CBCT images were evaluated to determine the maturation stage of the sutures according to the A, B, C, D, and E classification by Angelieri et al ( Fig 1 ).

Fig 1
Midpalatal suture maturation stages. Modified from Angelieri et al.

All images observed were acquired by the same protocol using an i-CAT scanner (Imaging Sciences International, Hatfield, Pa), 12-bit gray scale voxel size of 0.25 mm and field of view of 13 × 22 cm. To standardize the tomographic reviews, the images were analyzed by 2 calibrated examiners. Interobserver reproducibility in classifying facial growth patterns and maturation stages of the median palatal suture was assessed using the intraclass correlation coefficient and kappa, respectively. The interobserver reproducibility was excellent both linearly (intraclass correlation coefficient >0.9; P <0.0001) and nominally (kappa = 1.0). They were obtained at 2 different times when the facial growth pattern was determined and the classification of the maturational stages of the sutures.

To determine the pattern of facial growth, VERT Ricketts cephalometric analysis was used. The cephalometric points for this analysis were obtained using the Dolphin Imaging software (version 11.0; Dolphin Imaging and Management Systems, Chatsworth, Calif). The cephalometric points required to obtain cephalometric tracing were marked. The software illustrates all points and the sequence required for plotting. This offers the possibility of a close-up view of the area in question without overlapping structures. The union of points generated the digital paths, and the linear and angular values were automatically calculated. The facial pattern was determined in the final analysis ( Fig 2 ).

Fig 2
Dolphin Imaging software image for determining the facial growth pattern.

All images were processed and evaluated using the OnDemand3D software (Cybermed Inc, Seoul, South Korea). These procedures were performed according to the protocol described previously by Angelieri et al. The maturational stage of the median palatine sutures was determined by evaluating the central transverse axial dimension in the maxillary-mandibular palate. To enable suture maturation to be classified, all axial cross-sectional slices were arranged in a PowerPoint 2010 presentation (Microsoft Corp, Redmond, Wash) with a black background, using codes that were displayed sequentially on a high-definition computer monitor. Two transverse axial slices were used that showed whether the patient had any marked thickness or a palate curve. No adjustments were made to the contrast or brightness of these images. All images of the sutures were scored blindly by 2 investigators (R.O. and F.P.) in a dark room according to the maturational stages described by Angelieri et al.

Statistical analysis

Absolute and relative frequency distribution tables were constructed. Age and sex associations, along with facial growth patterns, were analyzed using the chi-square test. Associations between facial growth patterns, sex, age, and maturation stage were performed using chi-square and Fisher exact tests. All analyses were performed at a 5% significance level using R (version 3.2.2; R Foundation for Statistical Computing; Vienna, Austria).

Results

The study sample consisted of 90 CBCT images. Of these, 55 (61.1%) were female, and 35 were male (38.9%). The patients’ ages rangedia from 18 to 59 years, 55 of whom were aged <30 years (61.1%) and 35 were aged ≥30 years ago (38.9%). Age and sex showed no significant association with the different facial growth patterns ( Table I ).

Table I
Analysis of the association between age and sex and facial type
Variable Total Facial type P
Brachyfacial Mesofacial Dolichofacial
Frequency % Frequency % Frequency % Frequency %
Age
<30 y 55 61.1 18 60.0 20 66.7 17 56.7 0.7209
≥30 y 35 38.9 12 40.0 10 33.3 13 43.3
Sex
Female 55 61.1 18 60.0 18 60.0 19 63.3 0.9543
Male 35 38.9 12 40.0 12 40.0 11 36.7

Tables II and III show the sample distribution according to the facial growth pattern and maturational stages. A statistically significant association was found between the different patterns of facial growth and the maturation stages of midpalatal sutures ( P = 0.032). Thus, dolichofacial patients were more likely to have sutures that could undergo disjunction.

Table II
Analysis of the association between maturation stage of the midpalatal suture and facial type
Variable Total Facial type P
Brachyfacial Mesofacial Dolichofacial
Maturation stage Frequency % Frequency % Frequency % Frequency %
B 3 3.3 0 0.0 1 3.3 2 6.7 0.032
C 5 5.6 1 3.3 1 3.3 3 10.0
D 15 16.7 4 13.3 5 16.7 6 20.0
E 67 74.4 25 83.3 23 76.7 19 63.3

Oct 30, 2021 | Posted by in Orthodontics | Comments Off on Maturation stages of the sutures in the median palatine evaluated with cone-beam computed tomography
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