Midpalatal Suture Density CBCT Evaluation, Sex Gender and Growth Pattern Related Variability in 392 Adolescents Treated With Rapid Maxillary Expander Appliance

The aim of this paper was to evaluate the changes in the mean bone density values of the midpalatal suture in 392 young patients treated with the Rapid Palatal Expander appliance according to sex, gender, vertical and sagittal skeletal patterns. Materials and Methods. The evaluations were performed using the low-dose protocol cone-beam computed tomography scans at t0 (preoperatively) and t1 (1 year after the beginning of the therapy). The region of interest was used to calculate bone density in Hounsfield units (HU) in the area between the maxillary incisors. Results. CBCT scan data of 196 females and 196 males (mean age of 11,7 years) showed homogeneous and similar density values of the MPS at T0 (547.59 HU - 565.85 HU) and T1 (542.31 - 554.20 HU). Class III skeletal individuals showed a significant higher BD than the II class group at T0, but not at T1. Females showed significantly higher BD than males at t0 and t1. No significant differences were found between the other groups and between two-time points in terms of bone density values of the MPS. Conclusions. Females and III class groups showed significantly higher bone density values than males and II class, respectively. No statistically significant differences were found from T0 to T1 in any groups, suggesting that a similar rate of suture reorganization occurs after the use of the RPE, following reorganization and bone deposition along with the MPS.

A CBCT Evaluation of Midpalatal Bone Density in Various Skeletal Patterns

The purpose of this study was to evaluate midpalatal bone density (BD) by using cone-beam computed tomography (CBCT) according to gender, age, and vertical and horizontal skeletal patterns. CBCT images from 126 subjects (64 females and 62 males) were reoriented and analyzed in order to attain BD values at the midpalatal suture. Four age groups were used for classification (adolescence, 10 ≤ early < 14 years, 14 ≤ middle ≤ 17 years, and 17 < late ≤ 21 years; adult > 21 years). Vertical skeletal pattern categories were differentiated by the Frankfort horizontal line to mandibular plane angle (hypodivergent < 22°, 22° ≤ normovergent ≤ 28°, and 28° < hyperdivergent). Horizontal skeletal pattern differentiation was defined by ANB angle (Class III < 0°, 0° ≤ Class I ≤ 4°, and 4° < Class II). Females showed significantly higher BD than males (p < 0.001). As age increased, BD increased significantly (p < 0.001). There were no significant differences between vertical skeletal patterns. Class II showed significantly less BD than Class III (p < 0.05). With this information, clinicians can better understand BD trends of the midpalatal suture and, thus, better understand our patient’s anatomy and potential hurdles in successful treatment.

Novel Digital Measurement Technique to Analyze the Palatine Suture Expansion after Palatine Rapid Maxillary Expansion Technique

The aim of the study was to validate a novel digital measurement method to quantify the volume of the midpalatal suture after rapid maxillary expansion (RME). Material and methods: Eight patients with maxillary skeletal transverse deficiency were submitted to palatine suture expansion using the McNamara orthodontic appliance during a period of nine months. After 30 days of treatment, all patients were exposed postoperatively to a cone-beam computed tomography (CBCT) scan. Afterwards, the scans were uploaded into the three-dimensional orthodontic-planning software to allow the volumetric assessment of the palatine suture expansion through palatine rapid maxillary expansion using a McNamara appliance. The repeatability was analyzed by repeating twice the measures by a single operator and reproducibility was analyzed by repeating three times the measures by two operators, and Gage R&R statistical analysis was performed. Results: The expansion of the midpalatal suture by means of the rapid maxillary expansion technique, in terms of digital volume measurement, showed a repeatability value of 0.09% and between the two operators a reproducibility value of 0.00% was shown. Conclusions: The novel measurement technique demonstrated a high repeatability and reproducibility rate for volume assessment of the palatine suture expansion through palatine rapid maxillary expansion technique.

Miniscrew-assisted rapid palatal expansion (MARPE) protocols applied in different ages and stages of maturation of the midpalatal suture: cases report

Objective: To evaluate the Microimplant-assisted Rapid Palatal Expansion (MARPE), considered an alternative to surgical interventions for disjunction of the midpalatal suture in adolescent patients and young adults with maxillary transverse deficiency. The stage of ossification of the midpalatal suture, bone quality and adequate activation protocols are factors that can influence the quantity and quality of the orthopedic separation. Methodology: This paper demonstrates the application of MARPE in an unfavorable case report, of an adult patient with total crossbite, in an advanced stage of fusion of the palatine and maxillary processes, with poverty in the posterior bone volume, in comparison with the same therapy in an adolescent at an earlier stage of sutural maturation. In both cases, after tomographic examinations and oral scanning, the installations and recommended activation protocol were performed. These were not sufficient in the case of the adult patient, and generated side effects that, to be overcome, required changes in activations and additional maneuvers. Results: The application of MARPE may require clinical versatility to adopt differentiated protocols in relation to chronological age, bone thickness and sutural ossification stage. Conclusion: In the end, new computer tomography scans and a clinical examination showed satisfactory results in both patients. In the unfavorable case, the opening of the midpalatal suture occurred at more modest levels, but it was sufficient to correct the posterior crossbite.