Analysis of curtailing prevalence estimates of periodontitis post the new classification scheme: A cross-sectional study.

AIM: Among various dental ailments, periodontitis has always had a towering popularity. The inauguration of new classification scheme for periodontal diseases and conditions in 2017 World Workshop has a remarkable impact on the diagnosis of periodontal diseases worldwide. This study is based on comparison between the two classifications by American Academy of Periodontology for diagnosing periodontitis.
MATERIALS AND METHODS: This study focuses on the prevalence estimates of periodontitis by diagnosing the periodontal diseases using two different criteria simultaneously: the first criterion was based on the classification approved in 1999 World Workshop and the other criterion was based on the new classification scheme of periodontal diseases and conditions in 2017 World Workshop.
RESULTS: It was found that there was significant reduction in the prevalence estimates (P < 0.001) of periodontitis following the new classification scheme.
CONCLUSION: The new classification scheme recognizes the clinical salience of periodontitis and is more likely to influence the treatment modality of long sufferings of the patients having periodontal problems across the globe. The new classification will also lay the base for future research in the field of dentistry. More future studies are required to assess the prevalence of periodontitis following new classification scheme on a larger scale. Copyright:

INTRODUCTION

Periodontitis can be defined as microbially associated, host-mediated inflammation that results in loss of periodontal attachment, subsequently leading to edentulism.[1] There have been various researches that increase the understanding of human body and the various concepts of aging in a more complex manner when compared to that in 1999 where, in the last time, researchers in the field of periodontology agreed upon a classification system for periodontal diseases.[2] With the increase in knowledge and understanding of the subject, the new classification of periodontal diseases and conditions hence was necessary to overcome the discrepancies to properly diagnose and treat patients according to etiology and pathogenesis of disease.[3]

Against this background, this study stated the hypothesis that a difference can be expected in diagnosing periodontal disease using old and new classifications.

MATERIALS AND METHODS

This cross-sectional study was carried out in the Department of Periodontics and Implantology. Depending on the prevalence obtained in the pilot study, 95% confidence interval, 5% allowable error, and 80% power of the study, a sample size of 1236 patients was estimated to be included in the study. The study commenced on July 1, 2018; patients who visited the departmental OPD were examined using both classifications till the sample of 1236 was achieved using quota sampling which ended on November 30, 2018. Patients were made aware regarding the study and informed consent was obtained from them. For the periodontal assessment and diagnosis, mouth mirror and periodontal probe were used. Every patient was examined on the basis of following criteria simultaneously:

Method 1: Patients were classified according to classification proposed in 1999 International Workshop by American Academy of Periodontology for diagnosing periodontitis

Method 2: Patients were classified according to New Classification Scheme for Periodontal Diseases and Conditions proposed in 2017 World Workshop by American Academy of Periodontology for diagnosing periodontitis.

Inclusion criteria

Dentulous patients above 15 years of age, otherwise systemically healthy who visited departmental OPD from July 1, 2018 to November 30, 2018, were included.

Exclusion criteria

Edentulous persons

Children under the age of 15 years.

Table 1 depicts diagnostic criteria for periodontitis according to earlier classification.[4]

Table 1

Depicts diagnostic criteria for periodontitis according to earlier classification[3]

Case definitions proposed for population-based surveillance of periodontitis*
Case	Definition†
No periodontitis	No evidence of mild, moderate, or severe periodontitis
Mild periodontitis	≥2 interproximal sites with attachment loss ≥3 mm, and ≥2 interproximal sites with probing depth ≥4 mm (not on same tooth) or one site with probing depth ≥5 mm
Moderate periodontitis	≥2 interproximal sites with attachment loss ≥4 mm (not on same tooth), or ≥2 interproximal sites with probing depth ≥5 mm (not on same tooth)
Severe periodontitis	≥2 interproximal sites with attachment loss≥6 mm (not on same tooth) and ≥1 interproximal site with probing depth ≥5 mm

*These definitions are now commonly referred to as the CDC-AAP case definitions for surveillance of periodontitis, †Third molars excluded; total periodontitis is defined as the sum of mild, moderate, and severe disease. CDC-AAP – Centers for Disease Control and Prevention, American Academy of Periodontology

Table 2 depicts diagnostic criteria for periodontitis according to new classification.[1]

Table 2

Depicts diagnostic criteria for periodontitis according to new classification[1]

Periodontitis stage	Stage I	Stage II	Stage III	Stage IV
Severity
Interdental CAL at site of greatest loss	1-2 mm	3-4 mm	≥5 mm	≥5 mm
Radiographic bone loss	Coronal third (<15%)	Coronal third (15%-33%)	Extending to mid-third of root and beyond	Extending to mid-third of root and beyond
Tooth loss	No tooth loss due to periodontitis		Tooth loss due to periodontitis of ≤4 teeth	Tooth loss due to periodontitis of ≥5 teeth
Complexity
Local	Maximum probing depth ≤4 mmMostly horizontal bone loss	Maximum probing depth ≤5 mmMostly horizontal bone loss	In addition to Stage II complexity: Probing depth ≥6 mm Vertical bone loss ≥3 mm Furcation involvement class II or III Moderate ridge defect	In addition to stage III complexity: Need for complex rehabilitation due to: Masticatory dysfunction Secondary occlusal trauma (tooth mobility degree ≥2) Severe ridge defect Bite collapse, drifting, Flaring, ≤20 remaining teeth (10 opposing pairs)
Extent and distribution
Add to stage as descriptor	For each stage, describe extent as localized (<30% of teeth involved), generalized, or molar/incisor pattern

CAL – Clinical attachment loss

All information and data were personally collected by a single investigator after examination of oral cavities thoroughly: investigator being a periodontist. Oral cavities were examined for the presence of calculus, bleeding gums, shallow periodontal pockets, deep periodontal pockets, and clinical attachment loss (CAL). Periodontal pockets were assessed by careful exploration with a graduated periodontal probe with markings from 2, 4, 6, 8, 10, and 12.[4] Gingival recession and probing depth were measured at six sites per tooth. A total of 168 sites in a fully dentate individual were evaluated. The sites were mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, and distolingual for each tooth.[4]

Bleeding on probing was assessed using periodontal probe, which was inserted to the bottom of pocket and was gently moved laterally along the pocket wall. Bleeding on probing was rechecked for 30–60 s after probing.[5] After thorough clinical examination, bone loss was assessed radiographically, wherever required. Each patient was clinically examined carefully for diagnosing periodontitis.

Periodontal screening chart used for diagnosing periodontitis was as follows.

Figure 1 shows the periodontal chart by University of California, Los Angeles, USA.[5]

Figure 1

Periodontal chart by University of California, Los Angeles[5]

Statistical analysis

The data were compiled and spreadsheet was made using Microsoft Excel 2007. This was then exported to data editor page of SPSS version 20.0 – SPSS Inc., Chicago, Illinois, USA, which was used for statistical analysis. Intergroup comparison was done using Chi-square test for proportions and percentages: qualitative data of periodontitis on the basis of earlier and new classification of periodontal diseases. Level of significance was set at 0.05 and was analyzed to be 0.001 which is considered to be highly significant.

RESULTS

Figure 2 describes the allocation of participants.

Figure 2

The allocation of participants

Of the total participants, 725 were males and 511 were females. Patients were between 16 and 70 years of age (mean 35 ± 5 years).

Table 3 depicts that according to the earlier classification, there was the presence of periodontitis in 66.4% cases and absence of periodontitis was evident in 33.66% of examined cases. On the contrary in accordance with the new classification scheme, the presence of periodontitis was found to be in 41.42% of cases and the absence of periodontitis was found to be in 58.18% of examined cases.

Table 3

Comparison between earlier and new classification on the basis of presence and absence of periodontitis

Group	Periodontitis		Total, n (%)	Pearson χ2	P
	Absent, n (%)	Present, n (%)
Earlier classification	416 (33.66)	820 (66.34)	1236 (100)	38.608	0.001**
New classification	724 (58.58)	512 (41.42)	1236 (100)
Total	1136 (45.95)	1336 (54.05)	2472 (100)

Test applied: Chi-square test; **P≤0.001 - Highly significant

Figure 3 shows a graph showing the presence of periodontitis based on both the classification systems. The difference between the two methods of diagnosing periodontitis was found to be highly significantly different from each other.

Figure 3

Graph showing the presence of periodontitis based on both the classification systems

DISCUSSION

In light of the subject a classification can be defined to be arrangement of periodontal diseases and conditions in groups or categories which are in accordance to established criteria. A well established and simple classification is needed for crucial evaluation of etiology, pathophysiology of the disease affecting the periodontium, for proper diagnosis and treatment planning of the periodontal disease. Classification is required for logical systematic separation and organization of periodontal diseases and conditions. The classification of periodontal diseases was attempted for the first time in 1989 at World Workshop in clinical periodontics.[6] Later, in 1993, a simpler modification of the previous classification was agreed at the First European Workshop in Periodontology by various scholars.[7] Subsequently, in 1999, a classification system for periodontal diseases and conditions was put forward at International Workshop of Periodontology which was widely used in clinical practice for 17 years across the globe.[2]

This latest update of classification eliminates the drawbacks of the former classification. These drawbacks are enumerated as follows:

Inappropriate emphasis on severity of periodontal disease

Grouping of aggressive periodontitis as a separate category

Absence of peri-implant diseases in the classification

Absence of categorizing gingivitis as localized or generalized

Absence of neoplasms related to the periodontium

Inappropriate classification criteria for recession.

New classification has proposed a single case definition of periodontitis which states that a patient is labeled as a periodontitis case in the context of clinical care if:

Interdental CAL is detectable at ≥2 non adjacent teeth

Buccal or oral CAL ≥3 mm with pocketing >3 mm is detectable at ≥2 teeth.[1]

The new classification scheme re-categorizes various forms of periodontitis.[1] This also includes staging and grading system of periodontitis and the classification for peri-implant diseases and conditions.[1] The current modification in classification identifies only three forms of periodontitis – first: necrotizing periodontitis; second: periodontitis as a manifestation of systemic disease; and third: periodontitis.[2] The new classification scheme considers and complies complexity of management, severity, extent of disease, rate of progression, risk factors, and the inter-relationship of periodontitis with general health as one unit.[1]

The multi-dimensional staging and grading of periodontitis make this classification unique.[1] Staging in this classification includes CAL, probing depth, amount and percentage of bone loss, presence and extent of angular bony defects, tooth mobility, furcation involvement, and tooth loss due to periodontitis.[1] Grading on the other hand is divided into three levels.[1] The grades are divided as Grade A, Grade B, and Grade C, which represents low, moderate, and high risk for progression of disease, respectively.[3] This also encompasses additional aspects related to periodontitis progression, general health status, and other exposures such as smoking or level of metabolic control in diabetes.[3] A total of 1248 patients were examined during the study, out of which 1236 patients were included in the study who were diagnosed using both classifications, in which 725 were males and 511 were females. The prevalence estimate according to the earlier classification was found to be 66.4%, and on the contrary, it was 58.18% according to the new classification. The study reveals highly significant statistical difference (P < 0.001) in the prevalence estimates of periodontitis after the execution of new classification scheme, which could be assigned to nonperiodontal causes which were earlier categorized under periodontitis, such as gingival recession which was of traumatic origin, CAL in the distal aspect of a second molar or last molar present which may be associated with malposition or extraction of a third molar, root caries or dental caries approaching to cervical region of the tooth, an endodontic lesion which may be draining through the marginal periodontium, and vertical root fracture.[8]

The 1999 classification included converging parameters which lacked clear pathology-based differentiation between the diagnostic imprecision, stipulated categories, and implementation difficulties in decision-making.[2] The current classification aims to revise the classification system of periodontitis, which absorbs the new knowledge related to its etiology, epidemiology, and pathophysiology of the disease.[8] The new definition of aggressive periodontitis suggested in the new classification helps to evaluate preliminary stages of the disease.[9] This enables the clinician in diagnosis, prevention, and subsequently treatment of aggressive periodontitis.[9] Mucogingival deformities are categorized under other conditions affecting periodontium in the new classification scheme.[8] The association of gingival recession with dentin hypersensitivity or carious lesions on the exposed root surface places it under a separate category.[8] Thus, an appropriate treatment-oriented classification has been introduced for the assessment of gingival biotype, gingival recession severity, and associated lesions to help in clinical decision process.[8]

The findings improved the external validity, and hence, the results can be considered for generalizability.

CONCLUSION

Therefore, execution of the new classification scheme for periodontal diseases gives an insight of the etiology, pathology, and pathogenesis of the periodontal diseases which is beneficial for the patients and also brings about significant difference in the prevalence estimates of periodontitis. The study intends to exhibit the undemanding and effortless diagnosis of periodontitis in dental ministration for sawbones. The new classification scheme also lays the framework for future research work in dentistry. In view of the limitations, more future studies will be required for assessment of the prevalence estimates of periodontitis, following the new classification scheme covering a wider range of population.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.