Frequency of Malocclusion and Analyzation of Associated Risk

8/10/2019 Frequency of Malocclusion and Analyzation of Associated Risk

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FREQUENCY OF

MALOCCLUSION ANDANALYZATION OF

ASSOCIATED RISK FACTORS

UNDER SUPERVISION OF DR.FURQAN AHMED

MEMBERS:

KHALIDA FASEEH

MARRIAM KHAN

ZUMER NAYYERAMAL SAJID

AYESHA ASIF

YUSRA MASOOD

KARACHI MEDICAL AND DENTAL COLLEGE


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INTRODUCTION:

Occlusion is the relationship among all the components of masticatorysystem in their function,parafunction and dysfunction, whereas occlusionwhich is aesthetically and functionally not acceptable is referred to asmalocclusion.1.Ideally, all upper teeth fit slightly over the lower teeth. Thepoints of the molars fit the grooves of the opposite molar.The upper teethkeep the cheeks and lips from being bitten and the lower teeth protect thetongue.2.The term malocclusion encompasses all deviations of the teethand jaws from normal alignment,including a number of distinct conditions,like discrepanciesbetween tooth and jaw size (crowding andspacing),malrelationships of the dental arches (sagittal,transverse, andvertical) and malpositioning of individualteeth.3.There are differentcategories of malocclusion.

Class 1 malocclusion is the most common. The bite is normal, but the upperteeth slightly overlap the lower teeth.

Class 2 malocclusion, called retrognathism or overbite, occurs when theupper jaw and teeth severely overlap the bottom jaw and teeth.

Class 3 malocclusion, called prognathism or underbite, occurs when thelower jaw protrudes or juts forward, causing the lower jaw and teeth tooverlap the upper jaw and teeth.4.


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Symptoms

Abnormal alignment of teeth

Abnormal appearance of the face

Difficulty or discomfort when biting or chewing Speech difficulties (rare) including lisp

Mouth breathing (breathing through the mouth without closing the lips)

Signs and tests

Most problems with teeth alignment are discovered by a dentist during aroutine exam. The dentist may pull your cheek outward and ask you to bitedown to check how well your back teeth come together. If there is anyproblem, the dentist will usually refer you to an orthodontist for diagnosisand treatment.

Dental x-rays

head or skull x-rays.5.

Methods of recording and measuring malocclusion can be broadly divided

into two types i.e. qualitative and quantitative.6.while the severity or theextent to which a malocclusion deviates from the normal or ideal occlusioncan be quantified by using an occlusal index.7. Among the qualitativemethods of recording malocclusion Angles method of classifyingmalocclusion with or without modifications is probably the most widely

used.6.
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Cephalometric indicators are used to analyze the maxillary and mandibular skeletal

positions. Both angular and linear measurements have been proposed in theassessment of anteroposterior jaw-base relationships.8.Angles classification ofmalocclusions is universally accepted because of its simplicity as a method of

description and communication between dental professionals. Based on the

relationship of the mandibular first molars to the maxillary first molars, this system characterizes the

Class II malocclusions as having a distal relationship of the mandibular teeth relativeto the maxillaury teeth of more than one-half the width of the cusp. Two distinct typesof Class II malocclusion

exist, differing in the inclination of the maxillary central incisors. Class II Division 1malocclusions exhibit labially inclined maxillary incisors, an increased overjet with avertical incisor overlap varying from a deep overbite to an openbite and the Class IIDivision 2 malocclusion showing excessive lingual inclination of the maxillary centralincisors accompanied by a deep overbite and minimal overjet. An Angles Class IIImalocclusion means that the mandibular first molar is anteriorly placed in relation tothe maxillary first molar. It is a symptomatic or phenotypic description that uses thefirst molars and canines as criteria, and it has nothing to do with the maxillary andmandibular skeletal bases.Class II molar relationship may occur

unilaterally, depicted or classified as a class II subdivision of the affected side[9] ora bilaterally Class II on both the sides which is a frequently occurring type ofmalocclusion out of these two.[10] Dental malocclusion is present in all societies butits prevalence varies. There have been several studies investigating the prevalenceof various dentofacial characteristics11-15 but only a few have been conducted on anorthodontic

population.16,17There is a high incidence of Class I malocclusion in White Americans(Class I 52.5%, Class II 42.4% & Class III < 5%). Class I malocclusion is also moreprevalent in Black Americans (Class I 71%, Class II 16% & Class III 8.4%).


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There are a number of publications that prove the influence of genes on the

development of dentofacial system.18. The environmental factors include

forces and pressures from soft tissues and muscles surrounding the dentalarches, various habits (thumb sucking, nailbiting,etc.), and the effect oforthodontic appliances.19,20,21. The dentofacial system is also influenced bythe forces resulting from mastication.21,22. Therefore, although the majority ofthe etiological factors are clear,malocclusion are one of the most urgentstomatological problems. Individuals with Down syndrome (DS) andcerebral palsy (CP) are particularly prone to orofacial disorders.23.

Children with DS and CP have the habit of projecting the tongue against theteeth and out of the mouth and suffer frequent episodes of upper airwayinfection, which leads to a greater prevalence of mouth breathing andmalocclusion.24.

Children with the habit of maintaining their mouth open exhibit abnormaloromuscular movements and respiration, which compromises thecoordination and articulation of the lips and cheeks during speech and

swallowing.25 Oral habits and pressure on teethor

the maxillaand mandibleare etiologicalfactors in malocclusion.[26,27]
http://en.wikipedia.org/wiki/Toothhttp://en.wikipedia.org/wiki/Maxillahttp://en.wikipedia.org/wiki/Human_mandiblehttp://en.wikipedia.org/wiki/Etiologyhttp://en.wikipedia.org/wiki/Etiologyhttp://en.wikipedia.org/wiki/Human_mandiblehttp://en.wikipedia.org/wiki/Maxillahttp://en.wikipedia.org/wiki/Tooth


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In theactive skeletalgrowth,[28]]mouthbreathing, fingersucking, thumbsucking, pacifiersucking, onychophagia(nailbiting), dermatophagia, penbiting, pencilbiting, abnormalposture, deglutitiondisorders and otherhabits greatly influence the development of the faceand dentalarches.[29][30][31][32][33]

Prolonged use of a bottle

Extra teeth, lost teeth, impacted teeth, or abnormally shaped teeth

Ill-fitting dental fillings, crowns, appliances, retainers, or braces Misalignment of jaw fractures after a severe injury

Tumors of the mouth and jaw

Sociodemographic facrtors

Dental caries

Periapical inflammation.

The aim of this study was to determine the frequency/prevalence ofmalocclusion and to analyze the risk factors associated with malocclusion in

different age groups in a local samples of patients seeking dental treatment.data

for this study was retrived from the patients who sought dental treatment at dental

O.P.D in Karachi Medical & Dental College.
http://en.wikipedia.org/wiki/Skeletalhttp://en.wikipedia.org/wiki/Human_development_(biology)http://en.wikipedia.org/wiki/Malocclusionhttp://en.wikipedia.org/wiki/Malocclusionhttp://en.wikipedia.org/wiki/Mouthbreathinghttp://en.wikipedia.org/wiki/Fingerhttp://en.wikipedia.org/wiki/Thumbhttp://en.wikipedia.org/wiki/Pacifierhttp://en.wikipedia.org/wiki/Nail_bitinghttp://en.wikipedia.org/wiki/Nail_(anatomy)http://en.wikipedia.org/wiki/Dermatophagiahttp://en.wikipedia.org/wiki/Penhttp://en.wikipedia.org/wiki/Pencilhttp://en.wikipedia.org/wiki/Human_positionhttp://en.wikipedia.org/wiki/Deglutitionhttp://en.wikipedia.org/wiki/Facehttp://en.wikipedia.org/wiki/Dental_archeshttp://en.wikipedia.org/wiki/Dental_archeshttp://en.wikipedia.org/wiki/Malocclusionhttp://en.wikipedia.org/wiki/Malocclusionhttp://en.wikipedia.org/wiki/Malocclusionhttp://en.wikipedia.org/wiki/Malocclusionhttp://en.wikipedia.org/wiki/Dental_archeshttp://en.wikipedia.org/wiki/Dental_archeshttp://en.wikipedia.org/wiki/Facehttp://en.wikipedia.org/wiki/Deglutitionhttp://en.wikipedia.org/wiki/Human_positionhttp://en.wikipedia.org/wiki/Pencilhttp://en.wikipedia.org/wiki/Penhttp://en.wikipedia.org/wiki/Dermatophagiahttp://en.wikipedia.org/wiki/Nail_(anatomy)http://en.wikipedia.org/wiki/Nail_bitinghttp://en.wikipedia.org/wiki/Pacifierhttp://en.wikipedia.org/wiki/Thumbhttp://en.wikipedia.org/wiki/Fingerhttp://en.wikipedia.org/wiki/Mouthbreathinghttp://en.wikipedia.org/wiki/Malocclusionhttp://en.wikipedia.org/wiki/Malocclusionhttp://en.wikipedia.org/wiki/Human_development_(biology)http://en.wikipedia.org/wiki/Skeletal


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METHODOLOGY:

This cross-sectional study included patients who visited the Dental OPD, at

Karachi Medical And Dental College,Karachi, from June 2002 to April 2004.

Information regarding age and sex was obtained from the patients record

files. Both males and females were included in this study.

The inclusion criteria for the sample includes those with:

1.Presence with first permanent first molars.

2.Pre-treatment.

3.Orthodontic patients and patients seeking periodontal and operative

treatment.

The exclusion criteria includes patients with:

1.Significant past medical history.

2.Previous orthodontic treatment.

3.Previous prosthodontic treatment.

4.History of maxillofacial and plastic surgery.

5.Mixed dentition.

6.Congenital malformation.


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Patients were clinically examineed and were labelled under the

categories based on Angles classification, Occlusal index andIncisors classification.

ANGLES CLASSIFICATION:Angles classificaion categorizes as follows:

CLASS 1: A normal molar relationship exists but there is

crowding, misalignment of the teeth, cross bites, etc.

CLASS 11: Class II Malocclusion has two divisions to

describe the position of the anterior teeth. Class II Division 1 is when the maxillary anterior teeth are proclined anda large overjet is present.

Class II Division 2 is where the maxillary anterior teeth areretroclined and a deep overbite exists.

CLASS 111: A malocclusion where the molar relationship showsthe buccal groove of the mandibular first molar mesialy positioned tothe mesiobuccal cusp of the maxillary first molar when the teeth arein occlusion.


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INCISORS CLASSIFICATION:

Incisors were classified according to British Standard Institute (BSI) ofincisor classification.

Class Ithe lower incisal edges occlude with or lie immediately below thecingulum plateau of the upper incisors.

Class IIthe lower incisor edges lie posterior to the cingulum plateau ofthe upper central incisors.

Division 1- the overjet is increased, and the upper central incisors areproclined.

Division 2- the overjet is minimal or increased with retroclined upper centralincisors.

Class IIIthe lower incisor edges lay anterior to the cingulum plateau ofthe upper central incisors. The overjet is reduced or reversed.


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SOURCES: 1. Williams G, Bruyne DI, Verdonck A, Fieuws S, Carels C. Prevalence of

dentofacial characteristics in a Belgian orthodontic.

2. Malocclusion of teeth | University of Maryland Medical

Centerhttp://umm.edu/health/medical/ency/articles/malocclusion-of-

teeth#ixzz31iVRJxIG

University of Maryland Medical Center.

3. Lauc T. Orofacial analysis on theAdriatic islands: an epidemiologicalstudyof malocclusions on HvarIsland. Eur J Orthod 2003; 25:27378.

4.Malocclusion of teeth | University of Maryland Medical

Centerhttp://umm.edu/health/medical/ency/articles/malocclusion-of

teeth#ixzz31iXXpZCo University of Maryland Medical Center.

5.Malocclusion of teeth | University of Maryland MedicalCenterhttp://umm.edu/health/medical/ency/articles/malocclusion-of-

teeth#ixzz31iY0ZbNfUniversity of Maryland Medical Center.
http://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teethhttp://umm.edu/health/medical/ency/articles/malocclusion-of-teeth


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6. Tang EL, Wei SH. Recording and measuring malocclusion: A review of

the literature. Am J Orthod Dentofacial Orthop 1993;103:34451.

7. Keski-Nisula K, Lehto R, Lusa V, Keski-Nisula L, Varrela J. Occurance ofmalocclusion and need of orthodontic treatment in early mixed dentition. AmJ Orthod Dentofacial Orthop 2003;124:6318.

8. PREVALENCE OF MALOCCLUSION IN PATIENTS REPORTING IN

AN ORTHODONTIC OPD OF A TERITARY CARE HOSPITAL

Dr Hasnain Sakrania , Dr Syed Sheeraz Hussain B , Dr Omar Ansari,

Madiha Hanif. BDS, FCPS. Associate Professor, Department OfOrthodontics, Altamash Institute Of Dental Medicine, Karachi, PakistanBDS, DCPS,MCPS, FCPS, Assistant Professor, Department OfOrthodontics, Karachi Medical Dental College, Karachi, Pakistan BDS,Orthodontics Resident, Department Of Orthodontics, Altamash Institute OfDental Medicine, Karachi, Pakistan

9. Bishara SE. Class II malocclusions:diagnostic and clinical considerations

with and without treatment. Semin Orthod 2006; 12:11-24.


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10. Filho OGD, Ferrari Jr FM, Ozawa TO. Dental Arch Dimensions in Class

II division 1 Malocclusions with Mandibular Deficiency. Angle Orthod 2008;

78: 466-74.

11. Brunelle JA, Bhat M, Lipton JA. Prevalence and distribution of selected

occlusal characteristics in the U.S. population, 198891.J Dent Res

1996;75:70613.1

12. Foster TD, Day AJ. A survey of malocclusion and the need for

orthodontic treatment in a Shropshire school population. Br J Orthod

1973;1:738.

13. Ingervall B. Prevalence of dental and occlusal anomalies in Swedishconscripts. Acta Odontol Scand 1974;32:8392.

14.Johnson JS, Soetamat A, Winoto NA. A comparison of some features of

the Indonesian occlusion with those of two other ethnic groups. Br J Orthod

1978;5:1838.

15. Proffit WR, Fields HW, Moray LJ. Prevalence of malocclusion and

Orthodontic treatment need in the United States: estimates from the

NHANES III survey. Int J Adult Orthodon Orthognath Surg 1998;13:97106.


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16. Jones BW. Malocclusion and facial types in a group of Saudi Arabian patients

referred for orthodontic treatment: a preliminary study. Br J Orthod 1987;14:1436.

17. Yang WS. The study on the orthodontic patients who visited department oforthodontics, Seoul, National University Hospital.Taehan Chikkwa Uisa Hyophoe Chi1990;28:81121.

18. Proffit W. Contemporary Orthodontics. 3nd ed. St Louis: Year Book Medica Pub;2000.

19. Alvesalo L. Sex chromosomes and human growth. A dental approach. Hum.Genet. 1997; 101 (1): 1-5.

20. Takahashi S, Ono T, Ishiwata Y, Kuroda T. Effect of changes in the breathingmode and body position on tongue pressure with respitaroty-related oscillations. Am JOrthod Dentofacial Orthop.1999; 115 (3): 239-46.

21. Ther U, Sieber R, Ingervall B. Cheek and tongue pressures in the

molars areas and the atmospheric pressure in the palatal vault in young adults. Eur JOrthod. 1999; 21: 299-309.

22. Proffit WR. Equilibrium Therory Revisited: factors influencing position of the teeth.Angle Orthod. 1978; 48 (3): 175-86.

23. Weinstein S. On an equilibrium theory of tooth position. Angle Orthod.- 1963; 33:1-26.

24.Klein ET., E (1952). "Pressure Habits, Etiological Factors in Malocclusion".Am.

Jour. Orthod.38(8): 569587 25. Graber TM., T (1963). "The "Three m's": Muscles, Malformation and

Malocclusion".Am. Jour. Orthod.49(6): 418450.


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26. Bjrk A., Helm S., A; Helm, S (1967). "Prediction of the Age of Maximum

Puberal Growth in Body Height".Angle Orthod.37(2): 134143. doi:10.1043/0003-3219(1967)0372.0.CO;2. PMID4290545.[dead link]

27. Brucker M., M. (1943). "Studies on the Incidence and Cause of DentalDefects in Children: IV. Malocclusion". J Dent Res22(4): 315321.

28. Calisti L. J. P., Cohen M. M., Fales M. H., L. J.; Cohen, M. M; Fales, M.H (1960)."Correlation between Malocclusion, Oral Habits, and Socio-economic Level of Preschool Children". J. Dent Res39(3): 450454.

29. Subtelny J. D., Subtelny J. D. (1973). "Oral Habits - Studies in Form,Function, and Therapy".Angle Orthod.43(4): 347383

30. Aznar T., Galn A. F., Marn I., Domnguez A., T; Galn, AF; Marn, I;Domnguez, A (2006). "Dental Arch Diameters and Relationships to OralHabits".Angle Orthod.76(3): 441445.

31. Yamaguchi H., Sueishi K., H; Sueishi, K (2003). "Malocclusionassociated with abnormal posture". Bull Tokyo Dent Coll.44(2): 4354.doi:10.2209/tdcpublication.44.43

32. Wellington M.; Hall C. B. (2002). "Pacifier as a risk factor for acute otitismedia".Pediatrics.109(2): 351352.

33. Rovers MM; Numans ME; Langenbach E; Grobbee DE; Verheij TJ;Schilder AG (2008)."Is pacifier use a risk factor for acute otitis media? Adynamic cohort study". Fam Pract.25(4): 2336.
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Frequency of Malocclusion and Analyzation of Associated Risk