Preventive Dentistry

Preventive Dentistry Teaching & Research Section of Preventive Dentistry

Section 4 Epidemiology of Periodontal Disease

Periodontal disease Index for periodontal condition • OHI-S • PLI • GI • CPI Preventive dentistry

（1）OHI-S ( DI-S ) Preventive dentistry

（1）OHI-S (DI-S & CI-S) Preventive dentistry

（2） Turesky Modification of the Quigley Hein Index • Ramfjord index teeth Preventive dentistry

（2） Turesky Modification of the Quigley Hein Index • Plaque discoloration Preventive dentistry

（2） Turesky Modification of the Quigley Hein Index 0=No plaque 1=Slight flecks at the cervical margin 2=thin continuous band (≤1 mm) at cervical margin Preventive dentistry

（2） Turesky Modification of the Quigley Hein Index 3＝A band of plaque >1 mm but < 1/3 of the area 4＝covering 1/3 - 2/3 of the area 5＝covering ≥ 2/3 of the area Preventive dentistry

（3） GI Löe and Silness Index Preventive dentistry

（3）GI （Löe and Silness） Preventive dentistry

（4 ） CPI CPI probe • Gingival bleeding • Subgingival calculus • PD Preventive dentistry

（4 ） CPI ≥20years old 15～20years old Preventive dentistry

（4 ） CPI 0＝Healthy 1＝Bleeding observed 2＝Calculus detected, all the black band visible 3＝Pocket 4-5 mm Preventive dentistry

（4 ） CPI 4＝Pocket ≥6 mm (black band not visible) X＝Excluded sextant（<two teeth） 9＝not recorded Preventive dentistry

（4 ） CPI Preventive dentistry

Feature of distribition 15 years old Preventive dentistry

Feature of distribition 1 Area • Developing Vs Developed countries • Rural Vs Urban 2 time Preventive dentistry

Influential factors 3 population • age • gender male > female • race Preventive dentistry

Related factors • oral hygiene • smoking（duration、frequency、type） • nutrition • systemic diseases Preventive dentistry

Section 5 Epidemiology of Other Oral Diseases

Other oral diseases epidemiology • Oral cancer • Dental fluorosis • Cleft lip and palate • Dentofacial anomalies • Oral mucosal diseases Preventive dentistry

Oral cancer China 0.7，Thailand 4.6，India 12.6 /100,000 • District: one of the most common tumor in east south Asia • Time, age • Gender: male > female • Race Preventive dentistry

Oral cancer • District • Time, age • Gender: male > female • Race 口腔癌 Preventive dentistry

Dental fluorosis • Dean’s index • Based on the 2 most severely affected teeth (record the status if they are the same and record the less severe if they are not) Preventive dentistry

Dental fluorosis Preventive dentistry

Dental fluorosis • Fci = ( n×W ) / N • Fci=〔(0.5× Questionable)+(1× Very mild )+…+(4× Severe )×100％〕/ N Preventive dentistry

Dental fluorosis • Public health significance Preventive dentistry

Dental fluorosis Feature of distribution • area • urban, rural • age • dentition Preventive dentistry

Cleft lip and palate • One Cleft lip or palate case per 500～700 infants • factors Preventive dentistry

Cleft lip and palate • area • urban, rural • gender Preventive dentistry

Section 6 Oral Health Survey & Evaluation

The survey and evaluation of oral health • Purpose • Item • Index • Method • Sample size • Error and prevention Preventive dentistry

Item • General item • Oral health assessment • Questionnaire Preventive dentistry

Questionnaire data collection • Collect information that cannot be observed. knowledge practice attitude belief Preventive dentistry

Index • Caries---- • Periodontal diseases---- • Dental fluorosis---- Preventive dentistry

Methods Census（普查）----a complete enumeration of the umits to be studied (mass examination) : no sampling error : not practical, time consuming Preventive dentistry

Sampling --measurements on part of the population  --less resource demanding --quicker to complete --more cost-efficient --detail examination possible Preventive dentistry

Sampling Methods Most important issue is whether the sample can adequately represent the bigger population • Simple random sampling 单纯随机抽样 • Systematic sampling 系统抽样 • Stratified sampling 分层抽样 • Cluster sampling 整群抽样 Preventive dentistry

Simple random sampling sample population • Draw lots, throw a die • Random number table • Computer generated random number Preventive dentistry

Systematic sampling • In a list select every u unit in a list starting from a random number ( from 1 to uth) 1 N U U+k U+2k Preventive dentistry

Stratified sampling • Subdivide the population into strata and draw sample from each stratum independently • Common strata: age, gender, districts, etc sample sample population Preventive dentistry

Cluster sampling • Subdivide the population into several clusters (blocks of units) • All elements in these selected cluster are studied sample cluster cluster cluster population Preventive dentistry

Sampling Methods ？？？ Preventive dentistry

Multi-stage sampling • Sampling can take place in stages by repeating or combining the above sampling • More efficient for large scale surveys Preventive dentistry

Pilot survey • Include only one or two age groups to collect the minimum amount of data • 12 years +one other age group Preventive dentistry

OH survey ----pathfinder • to include the most important population subgroups • A stratified cluster sampling technique • Variations in level, severity and need Preventive dentistry

Index age groups • 5 yrs children ( primary teeth) • 12 yrs children ( permanent ) • 15 yrs adolescents • 35-44 yrs adults • 65-74 yrs elders Preventive dentistry

Sample size • N=K×Q/P • N subjects, p proporation • Q=1－P Preventive dentistry

Preventive Dentistry