Nghiên cứu đặc điểm nhân trắc và sự tăng trưởng đầu mặt ở trẻ em người Kinh từ 7 đến 9 tuổi ttta

Những kết luận mới của luận án: Đặc điểm nhân trắc đầu mặt ở trẻ 7 tuổi người Kinh Các kích thước khi đo trực tiếp ở nam lớn hơn nữ, các kích thước không khác biệt giữa ba loại khớp cắn. Dạng đầu chủ yếu là rất ngắn và ngắn (cvvđ: 513,33±12,53 mm; eu-eu: 138,90±5,20 mm; gl-op: 157,26±5,21 mm; po-n: 101,29±5,04 mm; po-pr: 112,83±8,74 mm). - Chiều rộng mặt, chiều rộng mũi, chiều rộng miệng, chiều rộng hàm dưới, chiều cao tầng mặt trên, giữa và dưới ở nam lớn hơn nữ, chiều rộng mũi loại I và II Angle lớn hơn loại III Angle, chiều cao tầng mặt giữa và dưới ở loại III lớn hơn loại I và II Angle (Zy-Zy: 120,97±4,76 mm; Al-Al: 30,92±2,56 mm; Ch-Ch: 38,06±2,80 mm; Go-Go: 90,06±4,76 mm; Tr-Gl: 52,14±3,86 mm; Gl-Sn: 54,71±4,14 mm; Sn-Me: 57,04±4,33 mm). - Các kích thước, chỉ số đo trên phim sọ nghiêng khác biệt không có ý nghĩa thống kê giữa nam và nữ trừ chiều dài nền sọ trước và sau ở nữ lớn hơn ở nam; hầu hết có sự khác biệt ý nghĩa thống kê giữa ba loại khớp cắn theo phân loại Angle trừ độ lệch nền sọ thì không có sự khác biệt (CC-N: 48,92±3,53 mm; Po-PtV: 37,11±2,35 mm; Ba-N/Xi-Pm: 60,55±5,09o; A/N-Pog: 1,37±3,03 mm; N-A/Fh: 90,39±3,06o; CC-Gn/Ba-N: 89,11±4,05o; N-Pog/Fh: 86,64±4,08o; Ls-E: 0,47±2,24mm; Li-E: 0,84±2,25mm; A1/B1: 122,65±12,08 o; R6HD/PtV: 11,35±3,23mm). Sự tăng trưởng đầu mặt từ 7-9 tuổi - Các kích thước khi đo trực tiếp và đo trên ảnh chuẩn hóa và phim sọ nghiêng tăng trưởng đều đặn theo tuổi từ 7-9 tuổi, nữ có xu hướng tăng trưởng sớm hơn nam, từ 8-9 tuổi có xu hướng tăng trưởng nhanh hơn từ 7-8 tuổi, mức gia tăng và tỷ lệ gia tăng giống nhau giữa hai giới trừ chiều rộng đầu và po-pr ở nữ lớn hơn ở nam. - Điểm giữa hố yên xương bướm (S): Di chuyển ra sau và lên trên, điểm khớp trán mũi (N): Di chuyển ra trước và lên trên theo trục Ba-N, điểm gai mũi trước (Ans): Di chuyển ra trước và xuống dưới, điểm cằm (Gn): Di chuyển xuống dưới và ra trước, điểm tâm cành đứng xương hàm dưới (Xi): Di chuyển ra sau và xuống dưới, điểm tâm cổ lồi cầu (Dc): Di chuyển ra sau và lên trên.

Trang 1

MINISTRY OF EDUCATION MINISTRY OF HEALTH

AND TRAINING

HANOI MEDICAL UNIVERSITY

TRUONG DINH KHOI

STUDY OF ANTHROPOMETRIC CHARACTERISTICS AND CRANIOFACIAL GROWTH IN KINH ETHNIC

CHILDREN FROM 7 TO 9 YEARS OLD

Trang 2

THESIS COMPLETED AT HANOI MEDICAL UNIVERSITY

Scientific instructor:

1 Associate Professor Luong Ngoc Khue, PhD, MD

2 Associate Professor Dao Thi Dung, PhD, MD

Reviewer 1: Prof Lê Gia Vinh

Reviewer 2: Assoc.Prof Le Thi Thu Ha

Reviewer 3: PhD Nguyen Dinh Phuc

Trang 3

A THESIS INTRODUCTION ABSTRACT

The age from 7 to 9 years old is the first period of general growth of the whole body as well as of the dental arches and craniofacial structure, and the time when the incisors are fully developed and the jawbone develops for the teeth eruption of next stage 1 During adolescence, the eruption of the first molars, the middle incisors and the growth in preparation stage for the next puberty 2, when the child is 7 years old, it is necessary to take the child away the first orthodontic examination for early detection of maloclusion and maleruption 3 At the age of 9, the lateral incisors, canines and premolars are ready for eruption, the time before the growth peak is of great importance in preventive orthodontic treatment and early intervention orthodontic treatment

4

Therefore,The growth of the head from 7 to 9 years old plays an important role for the orthodontist to refer to in order to have appropriate treatment for each age group, and to predict the growth trend of the craniofacial structure

In the world, there have been a number of head growth studies in children aged 7-9 years old, but mainly conducted on Caucasian people, so it is not completely suitable for Vietnamese people In Vietnam, there is no research

on this issue Based on the growth assessment, clinicians can better understand the medical condition, predict the growth trend to decide on the treatment plan and can visualize the future face in three dimensions Therefore, we chose the

topic "Studying of anthropometric characteristics and craniofacial growth

in Kinh ethnic children from 7 to 9 years old" with the following two

objectives:

1 Determination of facial features and anthropometric indices in year-old Kinh ethnic children in Hanoi by direct measurement, on standardized images and on digital cephalometric radiographs

2 Describe the craniofacial growth of the target group from 7 to 9 years old

THE URGENCY OF THE SUBJECT

Studying growth characteristics at the age from 7 to 9 years old has important significance in early diagnosis and orthodontic treatment in children In Vietnam, there is no research on growth at this age, especially the longitudinal research method that follows the research object for many years with a relatively large sample size The anthropometric characteristics of the head and the craniofacial growth provide craniofacial indexes that are the database for the orthodontists to refer to and predict the future facial morphology Besides, the indicators can also be used for other fields such as sculpture, painting, traffic safety or fashion and apparel The study is based on three methods of direct measurement, on standardized images and on

Trang 4

cephalometric radiographs, which can analyze and compare both hard and soft tissues of the head and face

PRACTICAL MEANING AND NEW CONTRIBUTION

1 This is the first study that combines a cross-sectional descriptive study and a longitudinal study using all three measurement methods including direct measurement, standardized image measurement and lateral cephalometric measurement This is also a study with a large enough sample size to be representative of the Kinh people aged 7 to 9 years old in Vietnam

2 Research on determining the characteristics and anthropometric indices

of head and face in 7-year-old Kinh children in Hanoi by direct measurement,

on standardized images and on digital cephalometric films, in order to give clinical practitioners of maxillofacial and plastic surgery and some other fields with a number of reference databases, used for analysis and comparison

3 The study describes the craniofacial growth of the group from 7 to 9 years old Kinh people, builds a model of craniofacial growth to help orthodontists predict the morphology and growth trend, In this day and age, orthodontics is increasingly interested in, so this is a valuable resource for clinical practitioners

THESIS STRUCTURE

In addition to the Research Statement and Conclusion, the thesis consists

of 4 chapters: Chapter 1: An overview of research issues, 33 pages; Chapter 2: Research Object and Methods, 27 pages; Chapter 3: Research results, 38 pages; Chapter 4: Discussion, 43 pages Thesis also has 77 tables, 1 diagram,

29 chart, 52 images, 136 references (including 28 in Vietnamese, 108 in English)

B THESIS CONTENT Chapter 1 THEORETICAL OVERVIEW 1.1 Some characteristics and craniofacial anthropometric indexes

The growth of skull bones depends on two phenomena:

- Surface bone accretion: There is bone accretion on the outside, increasing the volume of the skull, however, due to the increase in the volume of the brain inside, there is a phenomenon of bone resorption on the inside These two phenomena give the brain a three-dimensional increase in volume, but without

a significant increase in skull mass

- Osteogenesis at the joints: The phenomenon of bone formation from the connective tissue at the joints causes the bones to grow in lines perpendicular

to the joints Joint lines are present in three dimensions in space, so cranial bone formation grows in all directions The growth of the base of the skull is dependent on: Bone replacement due to lobar growth of brain, growth at the cartilaginous lines and cortical repair The maxillary bone is formed from the membranous bone, there is no replacement of cartilage, so the maxillary bone

Trang 5

grows by two processes: The phenomenon of accretion at the junction between the maxillary bone and the skull base of the skull, the accretion and dissolution of the surface of the maxillary bone 24,25,26 At birth, the mandible

is short, the condyle is minimally developed, with only fibrous cartilage and connective tissue surrounding the mandible The growth of the mandibular bone is based on the growth of membranes and cartilage, chondrocytes develop in specialized areas including: convex, parietal and jaw angle Growth

is based on cartilage growth and bone accretion - resorption on the bone surface 22,27 Soft tissue grows rapidly in thickness from birth to 3 years of age, grows steadily during puberty and ends in growth in adulthood

1.2 Mechanism of growth in the craniofacial region

The growth of craniofacial bones follows three mechanisms: growth at the joints, growth of cartilage and growth due to bone accretion/resorption The cranium grows at the joint lines formed from the narrowed fontanel area, the basal bone grows at the joints between the occipital, ethmoid, sphenoid bones, and the maxillary nasopharyngeal complex at the mid-maxillary joint lines, frontal bone, temporal bone and cheekbones Growth occurs in areas of chondrocytes containing chondrocytes, areas of cartilage that are not nourished by blood vessels by diffusion through the initial thin layers The process of bone accretion/resorption growth is based on two principles: the V-principle and the surface principle 22

1.3 Growth assessment methods

Method of consecutive comparing values of research characteristics measured on living bodies, on craniofacial radiographs and standardized images: Based on measured data of length, distance and angle, it is possible to evaluate growth, this comparison method is widely used because of its high quantification, ease of comparison between subjects, assessment of the difference in individual or on the same sample as well as between samples at same time or different times

Consecutive superposition method: The superimposed method aims to determine the position and growth direction of the research characteristics Cephalometric radiographs and photos of each object are superimposed at different times according to planes, lines, and reference points

1.4 Methods to study craniofacial growth

The method of using anthropometric instruments to directly measure the indicators on the face, the classic Martin anthropometric instrument kit includes: length ruler, distance measure, angle ruler, measuring tape for determining circumference Standard facial landmarks according to Farkas et

al (1992) 7

Trang 6

The use of standardized images supports the method of measuring on remote film quickly, safely, at low cost and convenient to store and exchange information; identify landmarks that are not visible on the film taken from a distance such as the wings of the nose, corners of the eyes, the edges of two lips; simple operation, saving time and manpower when measuring, can be analyzed by digitizing software on computer 65,66 The normalization of images

in Claman's (1990) 68 study makes the normalized image more valuable and reliable in the study

Ricketts' research emphasizes children's growth and direction of growth Ricketts analysis allows us to understand the morphology of the craniofacial and determine the type of face, the relationship between the craniofacial components Study on the ability to predict growth on cephalometric radiographs

1.5 Some studies in the world and Vietnam

1.5.1 Some studies in the world: There are a number of studies on the growth

of the head and face area based on measurements on the living body, measured on standardized images and on craniofacial radiographs, from which

to find out the increasing level, growth trends and factors affecting growth at different ages, including a study from 7 to 9 years old Research by Farkas L

G (1992) 7, (2005) 8, K Albertsson (2002) 9, Cleidy.A (2011) 10, Bishara S.E (1995) 11, Thilander B (2005) 12, (2009) 13

1.5.2 Some studies in Vietnam: There have been a number of studies on

craniofacial growth measured directly on living bodies, indirectly measured on standardized images and measured on craniofacial films, research by Ngo Thi Quynh Lan (2000) 14, Le Duc Lanh (2007) 15, Dong Khac Tham (2009) 16, Vo Truong Nhu Ngoc (2010) 17, Le Vo Yen Nhi (2011) 18, Truong Hoang Le Thuy (2012) 19, Le Nguyen Lam (2014) 20

Thus, based on scientific reports of domestic and international authors, there have been a number of studies on anthropometric characteristics and head growth, however, they are limited to a direct measurement method, measured on digital normalized images or on craniofacial radiographs; growth studies from 7 to 9 years old are still few, sample size is small, most of the studies are on Caucasian race, so the application of research results to Vietnamese people is not completely appropriate More studies help clinical practitioners, orthodontists have a basis for more accurate diagnosis and treatment planning

Chapter 2 SUBJECTS AND RESEARCH METHODS

2.1 Location and research time

2.1.1 Research location: Hanoi city

2.1.2 Research period: From April 2017 to October 2020

Trang 7

2.2 Research subjects

The study subjects at the beginning of the study were 7-year-old children (born from January 2012 to July 2012) at Lien Ninh Primary School, Lien Ninh Commune, Thanh Tri district, Hanoi city two years in a row

a Selection criteria:

Subjects were Kinh ethnic people with Kinh ethnic parents and grandparents, normal health, at the beginning of the study, the average age was 7 years ± 3 months according to the date of birth in the entry records of research subjects There is a mixed set of teeth with the first molars are fully grown, touching on both bimaxillary, and have the same occlusal relationship

of the first molars on both sides There are four fully grown two-molar incisors on the jaw No orthodontic treatment before and during the study period There were no congenital malformations of cleft palate or jaw deformity No disease affecting the development of the body and head - face area There was no serious infection or trauma to the maxillofacial region Children and their relatives (parents or guardians) agree to participate

b Exclusion criteria:

Study subjects had dissimilar first molars on both sides Having undergone orthodontic treatment or congenital malformations cleft palate, jaw bone deformity Having bad habits affecting facial growth such as lip-sucking, thumb-sucking, mouth-breathing, tongue thrusting Children lose baby teeth early or suffer from infectious diseases, serious trauma to the maxillofacial region Children and their relatives (parents or guardians) did not consent to participate in the study

2.3 Research design: The study was designed according to the descriptive cross-sectional and longitudinal research methods

2.4 Select a research sample

SD: Standard deviation of research index, X : Mean value of research index

ε: Relative difference between sample parameter and population, choose ε = 0,015 Based on the research of Truong Hoang Le Thuy, taking the average value of face width at 7 years old 19: X ±SD: 120,3±5,2 (mm), the minimum

sample size for each sex was calculated as n = 31,90 Thus, each gender has at

Trang 8

least 32 research subjects In fact, we conducted a study on 206 subjects (104 men, 102 women)

We conduct a convenience sample study purposefully to meet the research sampling criteria 125

Flowchart of the research process

2.5 Steps for conducting research

Step 1: Select Lien Ninh Primary School, Lien Ninh Commune, Thanh Tri

District, Hanoi, select research subjects by date of birth in the school's admission records, survey the ethnicity of parents and grandparents, a total of

489 children of Kinh ethnicity, age 7 years ± 3 months (according to date/month/year of birth) Every 12 months, we measure and re-collect the research data, for 2 consecutive years

Step 2: Subjects were taken to direct measurement, on standardized straight

and inclined images, and cephalometric films at the Institute of Stomatology Training, building A7, No 01 Ton That Tung, Hanoi, affiliated

Odonto-to the Hanoi Medical University), from April 18 Odonto-to April 25, conducted three times in two consecutive years

2.6 Data Collection Tools

2.7 Processing and analyzing data

The collected data was entered into the computer, then processed by info 6.0 program, SPSS 23.0 statistical software and statistical algorithm

Epi-2.8 Errors and how to control errors

2.9 Ethical issues in research

Trang 9

The study was approved by the Council of Ethics in Biomedical Research

at Hanoi Medical University

Chapter 3 RESEARCH RESULT 3.1 General characteristics of the research subjects:

Our study sample included 206 children, who started the study at the age

of 7 years and were followed up to 9 years of age, including 104 boys and 102 girls Male accounted for 50,49% and female accounted for 49,51% (Type I Angle: 36 male, 37 female; Type II Angle: 35 male, 33 female; Type III Angle: 33 male, 32 female)

3.2 Craniofacial anthropometric indices in 7-year-old Kinh children

3.2.1 Characteristics by direct anthropometric measurement method

Table 3.1 Head-to-face anthropometric size in 7-year-old Kinh children between three occlusal groups by direct measurement (mm) (n=206)

Dimensions Classification of occlusion according to Angle P

Class I Class II Class III General

General 110,92±5,24 121,87±6,13 105,52±5,40 112,83±8,74 P I-II ; P I-III ; P II-III < 0,017*

P1 (Sample T-test), P (*: One way ANOVA with Bonferoni test, **: Kruskal Wallis test with

Mann- Whitney test)

Head circumference (cvvđ), head width (eu-eu), head length (gl-op) statistically significant differences between the sexes in each type of occlusion according to Angle classification (p) <0,05), but there was no difference in these sizes between the three groups according to Angle's occlusal classification (p>0,05) The difference in po-n size was not statistically significant between the sexes and between the three types of occlusion (p>0,05) The difference between the two sexes is not statistically significant, the difference between the three types

of occlusion according to the Angle classification is statistically significant, po-pr dimension of the type II occlusion is larger than class I and class III occlusion (with p<0,017)

Table 3.2 Anthropometric characteristics by measuring technique on normalized images straight and inclined (mm) (n=206)

Trang 10

Dimensions Classification of occlusion according to Angle P

Zy-Zy

Male 122,56±5,06 122,66±4,95 122,00±4,90 122,41±4,93 P I-II ; P I-III ; P II-III >0,05**

Female 119,27±4,22 119,67±4,27 119,59±3,96 119,50±4,12 P I-II ; P I-III ; P II-III >0,05**

P 1 0,0046** 0,0022** 0,0130** <0,001**

General 120,89±4,91 121,21±4,84 120,82±4,59 120,97±4,76 P I-II ; P I-III ; P II-III >0,05** Al-

Al

Male 32,39±2,18 33,06±2,34 31,42±2,03 32,31±2,27 P I-II>0,017; P I-III ; P II-III <0,017*

Female 29,89±1,93 30,03±1,98 28,53±1,83 29,51±2,01 P I-II>0,017; P I-III ; P II-III <0,017*

P 1 <0,001** <0,001** <0,001** <0,001**

General 31,12±2,40 31,59±2,64 30,00±2,41 30,92±2,56 P I-II>0,017; P I-III ; P II-III <0,017*

Ch-Ch

P 1 0,0024* <0,001* 0,0014* <0,001*

General 38,03±2,83 38,37±2,95 37,77±2,60 38,06±2,80 P I-II ; P I-III ; P II-III >0,05** Go-

Go

P 1 0,0139* 0,0029* 0,0615* <0,001*

General 90,34±4,68 90,16±4,95 89,63±4,68 90,06±4,76 P I-II ; P I-III ; P II-III >0,05** Tr-

Gl

P 1 0,0053* 0,0231* 0,0276* <0,001*

General 52,32±3,73 52,18±4,07 51,89±3,81 52,14±3,86 P I-II ; P I-III ; P II-III >0,05** Gl-

Sn

Male 56,22±3,78 54,83±3,69 58,09±3,98 56,35±4,00 P I-II>0,017; P I-III ; P II-III <0,017*

Female 53,05±3,57 52,18±3,36 53,91±3,75 53,04±3,60 P I-II>0,017; P I-III ; P II-III <0,017*

P 1 <0,001* 0,0030* <0,001* <0,001*

General 54,62±3,98 53,54±3,75 56,03±4,38 54,71±4,14 P I-II>0,017; P I-III ; P II-III <0,017*

SN-Me

Male 58,03±4,27 56,94±3,88 59,97±4,43 58,28±4,34 P I-II>0,017; P I-III ; P II-III <0,017*

Female 55,41±3,48 53,91±3,36 58,16±3,95 55,78±3,96 P I-II>0,017; P I-III ; P II-III <0,017*

P 1 0,0019** <0,001** 0,0141** <0,001**

General 56,70±4,08 55,47±3,92 59,08±4,27 57,04±4,33 P I-II>0,017; P I-III ; P II-III <0,017*

P1 (*: Sample T-test, **: Mann- Whitney test), P (*: One way ANOVA with Bonferoni test, **: Kruskal Wallis test with Mann- Whitney test)

There is a statistically significant difference between the sexes when compared by sex in the same type of occlusion based on Angle's classification

in all sizes (with p < 0.05)

3.2.3 Characteristics measured on lateral cephalometric radiographs

Table 3.3 Anterior cranial base length, posterior cranial base length and cranial base deviation in 7-year-old Kinh children (n=206)

CC-N

(mm)

Male 48,09±2,46 51,19±2,49 45,11±2,42 48,19±3,47 P I-II ; P I-III ; P II-III <0,017*

Female 49,49±2,50 52,68±2,52 46,73±2,51 49,66±3,45 P I-II ; P I-III ; P II-III <0,017*

P 1 0,0184* 0,0169* 0,0103* 0,0026*

General 48,80±2,56 51,91±2,59 45,91±2,58 48,92±3,53 P I-II ; P I-III ; P II-III <0,017*

Po-PtV

(mm)

Male 36,58±2,13 37,44±2,16 35,71±2,11 36,59±2,23 P I-II ; P I-III ; P II-III <0,05**

Female 37,76±2,29 38,56±2,28 36,54±2,10 37,64±2,36 P I-II ; P I-III ; P II-III <0,05**

P 1 0,0029** 0,0022** 0,0014** 0,0002**

General 37,18±2,28 37,98±2,27 36,12±2,13 37,11±2,35 P I-II ; P I-III ; P II-III <0,05**

Ba-N/Fh

( o )

P 1 0,9736** 0,8491** 0,9895** 0,9032**

General 27,08±2,91 27,08±2,86 26,94±2,85 27,04±2,86 P I-II ; P I-III ; P II-III >0,05**

The length of the anterior cranial base (CC-N) and posterior cranial base (Po-PtV) were greater in women than in men in each type of occlusion; When comparing between three types of occlusion in the same sex, type II occlusion

is larger than type I, in class I occlusion is statistically significant (with p<0,05)

Trang 11

Table 3.4 Total facial height, lower facial height and

mandibular plane angle (n=206)

Ba-N/

Xi-pm

( o )

Male 59,98±3,02 55,89±2,85 66,53±3,04 60,68±5,25 P I-II ; P I-III ; P II-III <0,017

Female 59,68±2,88 55,95±2,82 65,86±3,03 60,41±4,94 P I-II ; P I-III ; P II-III <0,017

P 1 0,8505 0,8851 0,5434 0,7917

General 25,22±2,95 22,93±3,19 29,02±3,07 25,66±3,90 P I-II ; P I-III ; P II-III <0,017

(P1: Sample T-test; P: One way ANOVA with Bonferoni test)

Total facial height (Ba-N/Xi-Pm), lower facial height (Ans-Xi-Pm), mandibular plane angle (Go-Me/Fh) did not differ between the sexes in each type of occlusion (with p>0,05); when compared with the same sex, the sizes

of Type III were larger than those of Type I and Type II (with p<0,017)

Table 3.5 Convexity, position A, maxillary depth (n=206)

A┴

N-Pog

(mm)

Male 2,39±1,93 3,55±1,95 -2,13±1,72 1,35±3,05 P I-II ; P I-III ; P II-III <0,017*

Female 2,40±1,82 3,61±1,89 -2,08±1,83 1,39±3,02 P I-II ; P I-III ; P II-III <0,017*

P 1 0,9835* 0,9001* 0,9078* 0,9257*

General 2,40±1,86 3,58±1,90 -2,11±1,76 1,37±3,03 P I-II ; P I-III ; P II-III <0,017* Ba-N-A

( o )

P 1 0,4016** 0,9413** 0,9216** 0,5755**

General 62,52±2,84 65,16±2,80 60,44±2,7 62,74±3,36 P I-II ; P I-III ; P II-III <0,05** N-A/Fh

( o )

P 1 0,7158** 0,8443** 0,8008** 0,7773** P I-II ; P I-III ; P II-III <0,05**

General 90,46±2,94 91,42±2,96 89,22±2,92 90,39±3,06 P I-II ; P I-III ; P II-III <0,05**

The dimensions of facial convexity (A┴N-Pog), position of point A NA), maxillary depth (NA/Fh) in Kinh children aged 7 years, the difference was not statistically significant, when comparing men and women for each type of occlusion; When comparing the sizes between the types of occlusion, the average values of the same sex are in class II > type I > type III

(Ba-Table 3.6 Facial axis angle, facial depth, mandibular length(n=206)

CC-Gn/

Ba-N

( o )

P 1 0,9290 0,8200 0,5952 0,6769

General 86,79±2,96 83,11±2,84 90,16±3,03 86,64±4,08 P ; P ; P <0,017

Trang 12

Xi-Pm

(mm)

P 1 0,9706 0,9088 0,8992 0,8789

General 52,49±2,94 49,01±2,88 56,58±3,01 52,63±2,96 P I-II ; P I-III ; P II-III <0,017

(P1: Sample T-test; P: One way ANOVA kết hợp Bonferoni test)

Facial axial angle (CC-Gn/Ba-N), facial depth (N-Pog/Fh), mandibular length (Xi-Pm) when compared between sexes in each type of occlusion, the difference was not statistical significance between the sexes (with p>0,05), when comparing between three types of occlusion of the same sex, the sizes of type III Angle > type I Angle > type II Angle (with p<0,017)

Table 3.7 Some other dimensions on lateral cephalometric radiographs in

7-year-old Kinh children (n=206)

Dimensions Classification of occlusion according to Angle

Ls-E (mm) 0,49±1,21 2,60±0,99 -1,78±1,83 0,47±2,24 Li-E (mm) 0,84±1,22 2,96±1,29 -1,39±1,73 0,84±2,25 A1/B1 ( o ) 128,33±7,85 109,34±6,99 130,22±7,96 122,65±12,08 R6HD/PtV (mm) 11,71±3,00 9,78±2,77 12,59±3,31 11,35±3,23 A1┴A-Pog (mm) 2,33±2,32 3,38±2,40 2,13±2,33 2,61±2,40 A1/A-Pog ( o ) 25,98±2,89 26,80±2,86 25,50±2,89 26,1±2,92 B1┴A-Pog (mm) 22,35±3,15 24,96±3,32 25,14±3,16 24,09±3,45 B1/A-Pog ( o ) 2,16±2,20 3,30±2,40 3,43±2,62 2,94±2,46 B1-OP (mm) 1,68±2,37 3,45±2,50 2,37±2,47 2,48±2,54

3.3 Craniofacial growth characteristics in children from 7 to 9 years of age

Head circumference (cvvđ), head width (eu-eu), head length (gl-op), po-n and po-pr dimensions have an increasing rate regularly with age The first age from 8-

9 years old is older than from 7-8 years old in each type of occlusion according to Angle's classification, the difference is not statistically significant (p>0,05)

Table 3.8 Rate of increase in head circumference by direct measurement from

level (mm)

Male 7,33±2,53 7,91±2,63 15,24±4,09 0,1800**

Female 8,06±2,61 8,59±2,83 16,66±4,76 0,1511**

Trang 13

P 1 0,1539** 0,2531** 0,2250**

General 7,69±2,58 8,25±2,73 15,94±4,45 0,0530** Incresing

Face width, nose width, mouth width, mandibular width did not have statistically significant differences between the sexes in each age range and the same type of occlusion except for the increased rate of increase in females, which was greater than that in males

Table 3.9 Rate of increase in width by method on normalized images from 7-9

P1, P (*: sample T-test, **: Mann – Whitney test)

Increment level and rate of increase in the anterior and posterior cranial base lengths were not statistically significant between the sexes at the same growth age range (7-8 years, 8-9 years old and 7-9 years old) and the same type of occlusion according to Angle's classification except for the increase in the length of the anterior skull base from 7-9 years old in class II and III Angle

Tiêu đề	Study of Anthropometric Characteristics and Craniofacial Growth in Kinh Ethnic Children from 7 to 9 Years Old
Người hướng dẫn	Associate Professor Luong Ngoc Khue, PhD, MD, Associate Professor Dao Thi Dung, PhD, MD
Trường học	Hanoi Medical University
Chuyên ngành	Odonto-Stomatology
Thể loại	Doctoral Thesis in Medicine
Năm xuất bản	2022
Thành phố	Hanoi

Định dạng
Số trang	27
Dung lượng	1,35 MB