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UDC: 614.2
M. BADRAN, MAO JING
THE VALIDITY OF PONT'S INDEX APPLICATION TO BOTH CHINESE AND EGYPTIAN POPULATIONS (A PILOT STUDY)
Tongji medical college, Huazhong University of Science and Technology, Wuhan, China
M. Badran, Mao Jing - Department of Orthodontics, email: mo7ammed_badran@hotmail.com; (+86)15527794948
Abstract. Correlation between tooth size and dental arch size plays an important role in Orthodontic problems. Many indices were done elaborated by various researchers. One of those was Pont, who determined a method for the ideal dental arch width prediction, and this method has become known as Pont's index.
The aim of this study is to determine whether Pont's index could be applied on to both Chinese and Egyptian populations, and to compare the results with those calculated from other studies of different ethnic groups. A sample of 53 dental subjects were collected from Tongji hospital in Wuhan, China with age range from 14 to 21 years old, and another sample of 53 dental subjects were collected from Cairo university Hospital in Cairo, Egypt with age range from 16 to 23 years old.
Measurements were determined directly from plaster casts, including me-siodistal width of the four maxillary incisors, interpremolar and intermolar maxillary arch width, as stated by Pont. Correlation coefficients calculated between the measured interpremolar width and the calculated one according to Pont's index and measured intermolar width and the calculated one according to Pont's index respectively, were low in both Chinese (R values: 0.096 and 0.12) and Egyptian (R values: 0.013 and 0.21) samples.
It was concluded that Pont's index could not be applied to determine the ideal arch width values in both Chinese and Egyptian populations.
Keywords: Crowding, Maxillary Expansion, Inter-premolar width, Inter-molar width, Pont's index.
Mesiodistal width of the maxillary canines; he determined that the summation of the Mesiodistal width of the central and the Mesiodistal width of the lateral divided by two, was equal to the Mesiodistal width of the canine, size of the cranial base, both anterior and posterior facial heights as well as the genial angle (10).
Pont's index was recommended
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by too many researchers when the ideal occlusion was the goal of the treatment (11, 12). Even though there were some exceptions, other researchers believed that Pont's index was only applicable in some cases because there were not enough studies concerning the palatal
dimensions (13, 14, 15, 16).
depth measurement, as well as the lack of evidence to correlate arch length to other
I
Materials and methods. A sample
of 53 subjects with age range between 14-21 years and with females to males
Introduction. Many cases with class taining more stable final results (5, 6 7). ratio 60:40 was randomly selected from a crowding could be treat- One of these indices was determined by population that attended Tongji hospital,
I occlusion with
ed satisfactorily either by extraction or Pont
i
Tongji medical college in Wuhan, China. It non-extraction methods. Wisely, non-ex- |n 1909, Pont determined a method
was defined that the mothers and fathers
traction methods can be more efficient | to determine the idea| denta| arch width | of all the individuals were also Chinese.
-i
(1) than that of the extraction ones be- which is known now as "Pont's index" Another sample of 53 subjects with
cause of the shorter treatment duration (4). Even though he stated the method age range between 16-23 years and with (2). Extraction methods, even though are of measuring teeth to determine the females to males ratio 70:30 was also
S
more stable studies of long term sta- dental arch width was the only factor to randomly selected from a population
bility found that relapse may occur even be considered in the treatment p|an, he that attended the faculty of oral and den-
after premolar extraction (3). also focused on the assessment of the tal medicine, Cairo university hospital in
One of the common non-extraction |facial profi|e, angle's c|assification, and | Egypt. It was also defined that both moth-
methods is the arch expansion, which is the correlation between maxillary and ers and fathers of the selected individuals
considered a controversial procedure (4) mandibular arch to each other, as well were Egyptians.
due to the stability demands, so accord- as the midline as important factors to be The following criteria were used for
ing to this, many indices and methods considered.
have been determined to assist ortho-
Pont stated that the Mesiodistal
selection of both samples:
1. Angle class 1 occlusal rela-
dontists in predicting the ideal arch width width of the maxillary central and lat- tionship with normal overbite and over
required to overcome crowding and ob- ^ eral incisors can be used to predict the jet (overbite < 4mm and overjet < 3mm)
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2. Upper and lower well aligned dental arches.
3. Normal growth and developmental pattern.
4. No previous history of orthodontic or prosthodontic treatment.
5. Full presence of teeth from second molar to second molar in both maxillary and mandibular arches.
6. No missing teeth and no supernumerary teeth.
7. No presence of large restorations that can alter the mesiodistal diameter of the tooth.
8. No teeth with anomalous.
9. No buccal or lingual inclination of the teeth.
10. No diastema.
11. Lack of midline shift.
12. No peg shaped lateral incisors.
Alginate impressions were taken for
the patients and all of the impressions were poured immediately on the same day with hard dental stone. Taking into consideration correct and safe storage of impressions until they were poured, also all the dental casts were not soaped or waxed. Measurements of all the study casts were done by using a digital caliper with sharpened peaks.
Landmarks used for measurements were as follows:
1. Mesiodistal width of upper incisors; contact points
2. Maxillary inter-premolar width; distal pits of the maxillary first premolars
3. Maxillary inter-molar width; central fossae of the maxillary first molar
4. Calculated Maxillary interpre-molar width according to Pont's index: summation of the four maxillary incisors
width (s. 0 x 10%0
5. Calculated Maxillary intermolar width according to Pont's index: summation of the four maxillary incisors width
(s.£)X 10%4
In order to determine the errors as-
sociated with casts measurements and to ment by approximately 14 days and by ensure the accuracy, 25 cast models had the same investigator, it was found that been selected and their measurements no statistical significant difference was
were repeated after the first measure- found between the two measurements.
3kciIephmehtajIbhi>Ie h kjhhhIeckhe hccjIeiobahhh
Results
Egypt China P Value
30:70 40:60 0.568
an + SD) 21.2 ± 3.4 19.8 ± 2.3 0.188
Table (1): Anthropometric data:
This table shows the ratio between the males and females in both the Chinese and the Egyptian samples with no significant difference. Figure 5.
This figure shows the mean value of mesiodistal width of upper centrals and laterals for the Egyptian population.
intermolar width
Figure 4: Measurement of upper
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Mesiodistal width of the maxillary incisors (Egypt) ^
I
■III
Variables Mean SD CV
S_I 29.35 2.42 8.23
Interpremolar width 37.89 2.61 6.89
Intermolar width 46.32 4.37 9.44
CPV 36.68 3.02 8.23
CMV 45.85 3.77 8.23
(NCISAL WIDTH
Table (2): Measured and calculated IPW and IMW width in Egypt. This table shows the summation of the incisors, measured and calculated both IPW and IMW width in terms of Mean, SD, CV for the Egyptian sample.
This figure shows the mean value of mesiodistal width of upper centrals and laterals for the Chinese population.
Figure 5: Mesiodistal width of the maxillary incisors in Egypt
Figure (6): Mesiodistal width of the maxillary incisors in China
1
Variables Mean SD CV
Summation of maxillary incisors 30.58 1.43 4.67
Measured inter-premolar width(MIPW) 42.6 3.03 7.12
Calculated inter-premolar value(CPV) 38.32 1.91 4.99
Measured inter-molar width(MIMW) 46.88 2.5 5.33
Calculated inter-molar value(CMV) 47.78 2.21 4.63
Table (3): MIPW, CPV, MIMW and CMV in China This table shows S.I, measured and calculated both interpremolar and intermolar width in terms of Mean, SD, CV for the Egyptian sample.
Parameters R Value P Value
Measured inter premolar width & calculated inter premolar value 0.13 0.33
Measured inter molar width and calculated inter molar value 0.21 0.13
Table (4): Measured and calculated arch width values for Egyptian dental sample described in terms of R value, P value
Parameters R Value P Value
Measured inter premolar width & calculated inter premolar value 0.096 0.49
Measured inter molar width and calculated inter molar value 0.12 0.38
Table (5): Measured and calculated arch width values for Chinese dental sample described in terms of R value, P value
Discussion. Any orthodontic problem commonly originated from insufficient relation between the size of tooth and the dental arch size. Dental indices have been
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эксперименталды жэне клиникалыщ зе]рттеулер
also related to either one or both of these tic cases has been widely reported and 3. Little RM, Riedel RA, Engst variables, and Pont's index is one of these accepted by the orthodontic community ED. Serial extraction of first premo-indices. Pont did his study on French pop- because the relation between the max- lars—postretention evaluation of sta-ulation and he stated in his study that fur- illary and mandibular both anterior and bility and relapse. Angle Orthodontist, ther investigations are needed to check posterior dentition is related to the final 1990;60:225-262. the validity of his formula. orthodontic treatment prognosis. 4. Kahl-Nieke B, Fischbach H, These formulas were applied to dif- McKeown studied on a sample of Schwarze CW. Treatment and postreferent populations of different ethnic ori- casts' photographs which were divided tention changes in dental arch width gin to figure out whether the index could according to the degree of crowding (21). dimensions—a long-term evaluation be applied to different populations or not. She determined an average inter-molar of influencing cofactors. American This study is the first one to be applied on width (measured from the Mesiolingual Journal of Orthodontics and Dentofacial both Chinese and Egyptian population. surface of the upper first molars) of 36 Orthopedics, 1996;109:368-378.
Genetic variations and food habits mm in the individuals with no crowding 5. Howes AE. Case analysis
among different populations affect the teeth, which is strongly related to the re- and treatment planning based upon
growth of the jaw, different amount of ex- sults determined by Howe et al. (22). the relationship of the tooth materi-
pansion will be required for different jaw Gupta et al. found in his study a al to its supporting bone. American
sizes which means that Pont's index could correlation coefficient value for SUI with Journal of Orthodontics and Oral Surgery,
be different from population to another, inter-premolar arch width and that of the 1947;33:499-533.
as well as for racial groups. inter-molar arch as 0.48 which are the 6. Rees DJ, A method for as-
Stifter applied Pont's index on ideal same values as those of Pont's study (23). sessing the proportional relation of api-
and normal class I Occlusal relation. The Preliminary conclusion. Tooth cal bases and contact diameters of the
two groups were classified as "ideals" and size is an ethnic feature and plays an teeth. American Journal of Orthodontics,
"normals" to figure out any differences, important role in the maxillary expansion 1953;39:695-707.
and no corresponding relation was found decision making. Pont>s index cannot 7. McNamara JA, Brudon WL.
for "normals" (12). be applied to the Chinese population, Orthodontic and orthopedic treatment in
Greve applied Pont's index on one therefore new standards should be found the mixed dentition. Ann Arbor: Needham
hundred and two subjects with perfect to be applied to those, as well as to the Press; 1993. p. 60-61.
Occlusal relation and he found that only Egyptian population. Thus, new indices 8. Der Zhan index (Pont's index),
low correlation coefficient existed be- and standards should be determined to orthodontic, Zeit Shrift Fur Zahnartzliche,
tween the sum of the Mesiodistal diame- apply respectively. orthopedics. A clinical evaluation "Pont's
ter of the crowns of incisors and the arch Given the relatively small number of index". Angle orthodontist, 1970.
width in the premolar region (r=-0.34) subjects in this research, especially taking 9. Lavelle, GLB: Maxillary and
and the arch width in the molar region ( into account high number of population mandibular tooth size in different racial
) (17). in both ethnicities, data collection should groups and in different Occlusal catego-
Hotz suggested that deviations re- be continued for proper statistical ries. A. M. J. Orthodontics, 1972.
sult from Pont's formula may be relat- processing and making convincing 10. Cotton WN, Takano WS and
ed to long and narrowly shape jaws. He conclusions. Wong WW: The down's analysis applied
found that due consideration should be References: to three other ethnic groups. Angle's or-
given to the shape of the skull in arch 1. Proffit WR. Forty-year review thodontist, 1951.
form and width assessment (18). Smyth of extraction frequencies at a university 11. Stiffer J, "A study of Pont's
and Young determined that the tooth size orthodontic clinic. Angle Orthodontist, index", Howe's Ree's, Neff's and Bolton
and arch width relation was below the "r" 1994;64:407-414. analysis on class one adult dentition.
value (19). Korkhaus proposed index val- 2. Vig PS, Weintraub JA, Brown Angle's orthodontist, vol.28, no.4, 1958.
ues of 84 and 65 rather than Pont's values C, Kowalski CJ. The duration of ortho- 12. Gupta DS, Sharma VP and
of 80 and 64, and for he applied his study dontic treatment for patients with Aggarawal PS. "Pont's index as applied on
on Rhineland population (20). and without extractions. American Indians". Angle's orthodontist, vol. 49, no.
The importance of tooth size dis- Journal of Orthodontics and Dentofacial 4, 1979.
crepancies for the diagnosis of orthodon- Orthopedics, 1990;97:45-51. 13. Dalidian M, Sampson W,
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Townsend G. "Prediction of dental arch illary expansion indices ". The angle's or- 20. Korkhaus, Biomechaniche
development, an assessment of Pont's thodontist, vol. 65, no. 5, 1995. Gebiss Und Kieferorthopadie. Handbuch
index in three human populations ". 17. Greve K. Die Gültigkeit. Des Der Zhanheilk. J.F. Bergmann, Munich,
American Journal of orthodontics and Pont's Chen index. Fortschr. Orthodontic, vol.4, 1939, cited by Hortz R. Orthodontia
dento-facial orthopedics, vol. 107, 1933, 3:163-186. Cited by Moorees C. The in everyday practice. J. B. Lippincott Co.,
no.5,1995. dentition of the growing child, Harvard Philadelphia ,1961.
14. Joondeph DR, Riedel RA, university press, 1959. 21. McKeown M. The diagnosis of Moore AW. Pont's index: A clinical evalu- 18. Hortz R. Orthodontia in ev- incipient arch crowding in children, New ation. Angle's orthodontist, vol. 40, no. 2, eryday practice, J. B. Lippincott Co., Zealand dent. j. 1982,77:93-5
1970. Philadelphia, p. 63,196. 22. Howe RP, McNamara JA,
15. Worms FW, Speidel TM, 19. Smyth C, Young M. Facial O'Connor KA. An examination of dental Isaacson RJ and Meskin LH. "Pont's index growth in children with special reference crowding and its relationship to tooth size and dental arch form". The journal of the to dentition, medical research council, and arch dimension, Am J orthod. 1983, American dental association, vol. 85, no. special report series no. 171, London 193. 83:363-73.
4, 1972. Cited by Horowitz and Hixon: the nature 23. Gupta DS Riedel RA, and Moore
16. Nimikarn Y, Miles PG, O'Reily of orthodontic diagnosis C.V. Mosby Co. AW Pont's index: A clinical evaluation, MT and Weyant RJ. "The validity of max- St. Louis, 1966. Angle's othod.1979, 58:269-71.
TYMIH
M. BADRAN, MAO JING
КЫТАЙ ЖЭНЕ ЕГИПЕТ ПОПУЛЯЦИЯСЫНДА ПОНТ ИНДЕКС1Н КОЛДАНУ НЕПЗД1Л1П
Тонжи ауруханасы, Тонжи медициналык, колледжу Хуажон fbmbiM жэне технология университету Ухань, Кытай Халык, Республикасы
Тктщ Ka^Mi мен тк доfасынын, Ka^Mi арасында™ сэйкеспк ортодонтикалык, мэселелерде манызды рал атк,а-рады. Сэйкес алшем Yшiн каптеген зерттеуштер осы сала-да белгЫ бiр кaрсеткiштердi (индекс) жасады. Понт индекс! деген атпен эйпленген, тк доfасын мшаз болжау тэсЫн анык,таfан зерттеушiлердiн 6!р! Pont болып табылады.
Бул зерттеудiн мак,саты - Понт индекс к,ытай жэне египет популяциясында колданыла ма, соны анык,тау жэне алынfан нэтиженi баска эртурл! этникалык, топтар зерттеулерiнiн есептелген индекамен салыстыру. Ухань (Кытай) каласы Тунцзи ауруханасынын стоматологиялык бaлiмiнде 14-тен 21 жаск,а дейiнгi жас ерекшелiктiк тобында™ зерттеу субъектiлерiнiн жэне Каир (Египет) университетшщ госпиталiнде 16 жастан 23 жаск,а дежнп аралыкта^ субъектiлердiн тк доfаларынын 53 бедерiнiн Yлгiсi жинак,талды.
Понттын мэлiметiнше, алшемдер тарт жоfарfы KYрек тiстерiнiн мезиодистальды енiн, жоfарfы жак, доfасынын межпремолярлы жэне межмолярлы енiн к,оск,анда, тiкелей
РЕЗЮМЕ
M. BADRAN, MAO JING ОБОСНОВАННОСТЬ ПРИМЕНЕНИЯ ИНДЕКСА ПОНТА В КИТАЙСКОЙ И ЕГИПЕТСКОЙ ПОПУЛЯЦИЯХ
Медицинский колледж Тонгжи, Хуажонг Университет Науки и Технологии, Ухань, Китай
Соотношение между размером зуба и размером зубной дуги играет важную роль в ортодонтических проблемах. Для соответствующих измерений многими исследователями в этой области были разработаны определенные показатели (индексы). Одним из этих исследователей является Pont, определивший способ идеального прогнозирования зубной дуги, получивший известность как индекс Понта.
Целью данного исследования является: определить, применим ли индекс Понта к китайской и египетской популяции, и сравнить полученные результаты с рассчитанным индексом из других исследований различных этнических групп. Образцы из 53 слепков зубных дуг субъектов исследования в возрастной группе от 14 до 21 лет были собраны в стоматологическом отделении больницы Тунцзи в городе Ухань (Китай) и 53 аналогичных образца - в Каирском университетском госпитале (Египет) у субъектов в возрастном диапазоне от 16 до 23 лет.
Измерения были выполнены непосредственно на гипсовых слепках, включая мезиодистальную ширину четырех верхних резцов, межпремолярную и межмолярную ширину
Медицинский журнал Западного Казахстана
4.52.2016 œ.
30
эксперименталдык жэне клиникалыщ зерттеулер
гипс бедерлерде жасалды. Понт индексi бойынша есептел-ген елшенген межпремолярлы жэне межмолярлы еынщ арасындаfы есептелген жэне Понт индекс бойынша есеп-телген корреляция коэффициент!^ кытайлык, (R: 0,096 жэне 0,12 белпа) та, египетпк (R: 0,013 жэне 0,21 белпа) те Yлгiлер сериясында темен болды.
Б^з алдын ала к,ытай жэне египет популяциясында тiс доfасы еынщ мiнсiз белгiсiн анык,тау Yшiн Понт индексш к,олдануfа болмайды деген тужырь^а келдiк.
Бул зерттеудегi, эсiресе, ею этникалык, топтаfы ха-лык,тар саны жаедайында^ субъектiлер санынын, аздыfын ескере отырып, нак,ты кррытынды алу Yшiн тиiстi статисти-калык, ендеу мак,сатында мэлiметтердi жинак,тау жалfасын табуы тжс.
Нег'зг'! свздер: т'1стерд'н тытыздыт, жогарт жак,тын кенеюi, межпремолярлы енмежмолярлы ен^ Понт индекс.
верхнечелюстной дуги, как заявлено Понтом. Коэффициенты корреляции, рассчитанные между измеренной межпре-молярной и межмолярной шириной и расчетной по индексу Понта, были низкими как в китайской (значения R: 0,096 и 0,12), так и в египетской (значения R: 0,013 и 0,21) серии образцов.
Мы пришли к предварительному выводу, что индекс Понта не может быть применим для определения идеального значения ширины зубной дуги в китайской и египетской популяциях.
Учитывая относительно небольшое количество субъектов в данном исследовании, особенно на фоне численности населения в обеих этнических группах, сбор данных должен быть продолжен с целью надлежащей статистической обработки для получения убедительных выводов.
Ключевые слова: скученность зубов, расширение верхней челюсти, межпремолярная ширина, межмолярная ширина, индекс Понта.
УДК: 616-001.14-092.9:612.017.1:612.67
Т.В. БОЧАРОВА, И.В. СОРОКИНА
ДЛИТЕЛЬНАЯ СВЕТОВАЯ НАГРУЗКА КАК ФАКТОР ПРЕЖДЕВРЕМЕННОГО СТАРЕНИЯ
ИММУННОЙ СИСТЕМЫ
Харьковский национальный медицинский университет, Харьков, Украина
Бочарова Т.В. - к.м.н., ассистент кафедры патологической анатомии, e-mail: bochata@ukr.net ;
Введение. Свет является необходимым условием существования всего
Сорокина И.В. - д.м.н., профессор, и.о. зав. кафедрой патологической анатомии. живого на Земле. Развитие современ
Аннотация. Эксперимент проведен на кроликах, которые содержались на стандартном рационе при разных световых режимах.
Подопытные животные находились в условиях круглосуточного освещения в течение 6 и 12 месяцев. Проведено морфометрическое исследование костного мозга, тимуса и селезенки.
В ходе эксперимента установлено прогрессивное снижение плотности клеточных элементов в центральных (корковый и мозговой слой тимуса, костный мозг) и периферических (Т- и В-зоны селезенки) органах иммунной системы после 6 и 12 месяцев круглосуточного освещения. Снижение плотности клеточных элементов в тимусе, который является наиболее уязвимым органом при стрессе, соответствуют структурным нарушениям в периферических органах иммунной системы. Степень выраженности обнаруженных изменений зависит от длительности воздействия и свидетельствует о снижении функциональной активности и преждевременном старении иммунной системы.
Ключевые слова: иммунная система, костный мозг, тимус, селезенка, круглосуточное освещение.
ной науки позволило создать разные источники искусственного света, которые с успехом применяются в нашей жизни. Большинство
повседневной людей не задумываются о возможных негативных последствиях контакта с такими источниками, а наоборот широко используют их в быту и на работе. Тем не менее, доказано, что искусственное освещение может быть фактором риска развития возрастной патологии и даже привести к преждевременной
Относительно немногочислен-
смерти [1, 2].
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ными являются исследования о вли-функционирование иммунной систе-
длительного освещения на
