The Relationship Between Midpalatal Suture Maturation And Growth Of Maxilla

ObjectivesIn this study,CBCT was used to investigate the relationship between the maturation stage of midpalatal suture and the sagittal,transverse and vertical development of maxilla.Materials and MethodsCBCT imaging data of untreated patients were collected from September 2018 to January 2020 in the orthodontic department of the Stomatological Hospital of Shandong University.There were 150 males and 150 females aged from 6 to 21 years and no obvious abnormality in physical development,300 patients totally sampled.Screenshots and measurements were taken from Dolphin 11.8:In the maxillary midsagittal plane,screenshots were taken from the central hard palate.All the collected images were divided into stages A to E according to the midpalatal suture maturity staging method recommended by Angelieri et al.Then the parameters between the bone markers were measured,including sagittal length of maxilla,width of maxilla,width of lower margin of hard palate,width of alveolar process,depth of palatal vault,and thickness of hard palate.With Dolphin 11.8 software,Screenshots of cervical vertebra C1～C4 were obtained by lateral cephalogram combined from CBCT.The images were divided into CS1～CS6 stages according to the cervical vertebral maturation(CVM)staging method recommended by McNamara et al.All data were imported into SPSS,and Kendall’s tau-b correlation coefficient was used to test the correlation between cervical vertebra and palatal suture maturation stage,with P<0.01 as the statistical standard.One-way analysis of variance(ANOVA)was used to compare the differences of age and maxillary development in different stages of the midpalatal suture.LSD analysis was used to compare the differences of statistically significant data between every two groups,and then the same method was used to analyze the male and female respectively,with P<0.05 as the statistical standard.Results1.In the 6～21 years old group,there were significant differences at the A to E stages of the midpalate suture(P<0.05),with the respectively mean ages of 7.94±1.23y(stage A),9.66±1.92y(stage B),13.55±3.29y(stage C),16.69±2.88y(stage D)and 18.46±1.73y(stage E).The average age of male was slightly higher than that of female in each stage.In the total sample,the number of people in stage C and D is the largest.In the male sample,the number in stage C is the largest,while in the female,the number in stage D is the largest;2.There was a significant positive correlation between midpalatal suture maturation and CVM,Kendall’s tau-b=0.630,P<0.01;and respectively,98%,97.3%and 90.3%of the CS1～CS3 stages belonged to the A～C stage;3.The growth of maxilla at different stages of midpalatal suture were different,and the sagittal length of maxilla was significantly different between each group at stages A to C(P<0.05).Statistically significant differences exist in maxillary transverse width at nasal floor level in stage A～D,maxillary width at lower margin of hard palate and alveolar process width in stage A～C among all groups(P<0.05),and respectively the minimum and maximum values of the above measurement items were in stage A and E.The vertical depth of palatal vault was significantly different among all groups in stage B to D(P<0.05).The thickness of hard palatal basal bone increased first and then decreased,and the maximum value was at stage C.There was no significant difference in palatal basal bone width between A and E stages(P=0.193).4.In general,the mean values of maxilla in each stage of midpalatal suture were higher in males than in females,but the growth stages were different between males and females.Most of the rapid growth stage of the male sample was in the B～D stage,while the female sample was in the A～C or A～D stage.The palatal basal bone thickness at 3mm and 6mm from the midpalatal suture reached its maximum at stage D and C respectively,while the palatal basal bone width showed no statistically significant difference between both male and female(P=0.185,0.149).Conclusions1.There was significant correlation between midpalatal suture maturation and age,and with differences in two genders,the maturation of midpalatal suture in female was earlier than male;2.Significant positive correlation exists between palatal suture maturation and cervical vertebral maturation;cervical vertebra in CS1～CS3 could be inferred that the midpalatal suture was in the A～C stage.3.The maxillary bone grew and expanded with the maturity of the palatal suture,and there were some differences and overlap in the growth and development stages of each direction.Generally,the maxilla began to grow rapidly in the stage A～B(7.94～9.66y),slowed down in the stage C～D(13.55～16.69y),and stabilized in the stage D～E(16.69～18.46y);4.There are some similarities and differences in the growth and development of the maxilla in different genders.In general,the growth of the maxilla in females are earlier than males,and the total increment of transverse width of females was larger than that of males;the measured values of all directions in males are greater than females,and the total increase of males in the sagittal and vertical directions was larger than that of females.