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 Table of Contents  
Year : 2021  |  Volume : 6  |  Issue : 1  |  Page : 32-35

Prevalence of various classes of kennedy's classification – a cross-sectional survey

Department of Public Health Dentistry, Amitra Institute of Dental Science, Kochi, Kerala, India

Date of Submission06-Oct-2021
Date of Acceptance21-Oct-2021
Date of Web Publication29-Nov-2021

Correspondence Address:
Dr. Lakshmi Menon
Department of Public Health Dentistry, Amirta Institute of Dental Science, Kochi, Kerala
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijosr.ijosr_5_21

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Introduction: The design of prosthetic replacement depends upon the patterns of partial edentulism. The aim of the classification of partially edentulous arches is to facilitate the communication of prosthesis designs and treatment options among professional colleagues, students, and technicians. The aim of this study was to determine the prevalence of various classes of Kennedy's classification in patients reporting to Saveetha Dental College. Materials and Methods: One hundred and seventy patients were recruited in this study from February 2015 to May 2015 of the age group of 30–60 years. Kennedy's classification was utilized after applying Applegate's rules to record the partial edentulism. Results: One hundred and one male patients and 69 female patients participated in this study. Out of this, 71 were bite cases and 99 were single arch cases. Partial edentulism in the maxillary arch was found in 22.3% patients, whereas 35.9% patients had partial edentulism in the mandibular arch. The remaining 41.8% of patients had missing teeth in both arches. Kennedy's Class I was found to be most common, whereas Kennedy's Class IV the least common. Conclusion: A higher frequency of tooth loss due to dental caries and negligence of oral health among the patients in this study is quite alarming and is suggestive of need to create the awareness among dental health-care system for timely prevention of diseases and factors leading to tooth loss. By bringing about the awareness of tooth loss and available treatment options, the dental needs of the community could be met leading to an overall improvement in their quality of life.

Keywords: Applegate's rules, Kennedy's classification, mandible, maxilla, partial edentulism

How to cite this article:
Ajith A, Menon L. Prevalence of various classes of kennedy's classification – a cross-sectional survey. Int J Soc Rehabil 2021;6:32-5

How to cite this URL:
Ajith A, Menon L. Prevalence of various classes of kennedy's classification – a cross-sectional survey. Int J Soc Rehabil [serial online] 2021 [cited 2024 Feb 29];6:32-5. Available from: https://www.ijsocialrehab.com/text.asp?2021/6/1/32/331480

  Introduction Top

Teeth are the key entities of stomatognathic system for mastication, phonation, and esthetics.[1],[2] Many options are available for replacing missing teeth such as removable partial dentures, fixed partial dentures, and implant-supported prosthesis.[3] Conservative treatment modalities used to treat partial edentulism in patients such as dental implants also happen to be the most expensive. This happens to limit their availability to lower socioeconomic groups.[4] Hence, it should not be much of a surprise that conventional removable prosthodontic treatment modalities continue to outnumber implant tooth replacements in general dental practice. Removable partial prosthesis is a versatile, cost-effective, and reversible treatment method for partially edentulous patients of any age. The design of prosthetic replacement depends upon the patterns of partial edentulism. The aim of classification of partially edentulous arches is to facilitate the communication of prosthesis designs and treatment options among professional colleagues, students, and technicians. The classification is also helpful in recording history of patients.[5] Different prosthodontists had proposed many classification systems.[6] Each classification system is associated with its own merits and demerits. The ultimate goal of any classification system and is improved communication and consistency within the dental professionals. Different classifications may also have associated treatment principles that assist in treatment standardization and teaching. Kennedy's system of classification is most widely used.[7] The Kennedy classification system's main differentiating factor is its ability to quickly and clearly demonstrate the location of tooth support in relation to edentulous spaces. Due to its simplicity, it does not make judgments regarding condition or position of the remaining teeth. There are many instances, in which Kennedy's classification is difficult to apply. For such special situations Applegate's rules are applied.[8] The objective of this study was to determine the prevalence of various patterns of partial edentulism, using Kennedy's classification system, of patients reporting to Saveetha Dental College and Hospitals.

  Materials and Methods Top

This study was undertaken in private dental college Hospitals from February 2015 to May 2015. After approval from institutional ethical review Committee, the data for this study were compiled from the patients fulfilling the inclusion criteria. Name, age, gender, cause of tooth loss, periodontal health, and Kennedy's class along with modification spaces were recorded. Informed consent was taken from all patients. History was taken, which was followed by detailed clinical examination for partial edentulism. Whether only anterior or only posterior or both anterior and posterior teeth were missing was recorded. If assessment of missing anterior teeth was in question, anterior teeth were considered missing, if the patient's prosthesis consisted of a prosthetic anterior tooth. This avoided misrepresentation of large diastema's or spaces closed due to tooth migration. The total number of missing teeth was recorded. Fixed prosthodontic pontics and closed spaces were not considered missing teeth. Kennedy's classification system modified by Applegate was used in this study.

  Results Top

A total of 170 patients with partial edentulism were examined, in which 101 were male patients and 69 were female patients. Out of this, 71 were bite case and 99 were single arch cases, resulting in examination of 241 dental arches in total. Partial edentulism in maxillary arch was found in 22.3% patients, whereas 35.9% patients had partial edentulism in mandibular arch. The remaining 41.8% of patients had missing teeth in both arches [Table 1]. Caries are found to be the most common cause of tooth loss in patients with edentulism (72.4%) followed by periodontal diseases (17%). The distribution is given in [Figure 1]. Kennedy's class I (44.3%) was found to be most common, whereas Kennedy's class IV (11%) the least common [Figure 2]. Male predilection is higher in all Kennedy's classification than female [Figure 3].
Figure 1: Pie chart showing causes of tooth loss

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Figure 2: Bar chart showing incidence of various classes of Kennedy's classification (in %)

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Figure 3: Bar chart showing distribution of Kennedy's classification according to gender (in %)

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Table 1: Distribution of Kennedy's classification according to dental arches

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  Discussion Top

The presence or absence of teeth acts as a good indicator of the oral health of an individual in general. Oral health is an important component of both overall health and quality of life, as oral health and general health are interdependent. Oral disease creates a major public health burden worldwide and receives inadequate attention in many low- and middle-income countries (World Health Organization).[9] Systemic conditions have oral manifestations that increase the risk of oral disease, which in turn is a risk factor for various systemic diseases. Tooth loss is recognized as an individual risk factor for a range of systemic conditions, such as hypertension, stroke, cardiovascular disease, diabetes, and coronary heart disease. Tooth loss affects the quality of life of an individual resulting in reduced efficiency and function of the masticatory system and the appearance of the individual. By reduced chewing ability in individuals with tooth loss, nutritional deficiencies may be seen, and intakes of certain foods could probably be reduced. There is strong evidence that a diet high in fruits and vegetables improves systemic immunity and protects our body against obesity, diabetes, cardiovascular disease, and many other cancers.[10] The recommended intake of fruits and vegetables is 400 g/day. Thus, tooth loss will ultimately lead to the poor dietary intakes which in turn cause poor nutritional status. Masticatory performance and biting force are greater in dentate individuals followed by partially edentate and completely edentulous individuals.[11] Most of the patients evaluated in this study had missing posterior teeth, and in such partially edentulous subjects, biting force and masticatory ability is very much lower compared to dentate individuals, which was the prime concern in replacing the missing posterior teeth. Enlargement of the tongue, reduction in the vertical dimension, interocclusal space and lower facial height of the individual are few common effects of tooth loss. The reasons for tooth loss may be due to dental caries, periodontal disease, traumatic accidents, impaction, orthodontics, supernumerary, preparation for radiotherapy, or even due to congenital and developmental disorders.[12] The two most common causes of tooth loss in Asian population are dental caries and periodontal disease.[13] Secondary reasons for tooth loss are restricted access to dental services, health systems, and lack of oral health care.[14] These individuals with a high percentage of tooth loss need prosthetic restorations to restore the form, function, and esthetics.

Several methods have been proposed to classify the partially edentulous arches on the basis of the potential combinations of teeth to ridges. At present, Kennedy's classification is probably the most widely accepted one. Kennedy divided all partially edentulous arches into four main types. In his classification, edentulous areas, other than those determining the main types, were designated as modification spaces. The Kennedy classification is as follows.[15]

  • Class I – Bilateral edentulous areas located posterior to the remaining natural teeth
  • Class II – A unilateral edentulous area located posterior to the remaining natural teeth
  • Class III – A unilateral edentulous area with natural teeth remaining both anterior and posterior to it
  • Class IV – A single but bilateral (crossing the midline) edentulous area located anterior to the remaining natural teeth.

The results of this study showed that the frequency of partial edentulism is higher in mandible than maxilla in our population and Class 1 is the most common and Class 4 is the least common. This is in concordance with the study carried out by Curtis et al.,[16] at University of California, school of dentistry. Anderson and Lammie[17] investigated the prevalence of the classification of removable partial dentures at Birmingham Dental Hospital in the United Kingdom. Out of a total of 417 removable partial dentures, 208 (49.9%) were Kennedy Class I, 76 (18.2%) Class II, 101 (24.2%) Class III, and 32 (7.6%) Class IV. This was the earliest study of Kennedy classification prevalence. Basker and Davenport[18] conducted survey in three commercial dental laboratories in the United Kingdom, resulting in examination of 80 maxillary and 44 mandibular cast metal framework removable partial dentures. Kennedy Class III (69%) was the most frequent maxillary removable partial denture while Class II was the most frequent in the mandibular arch (43%). Interestingly, the study was repeated 10 years later for comparison purposes.[19] This time five commercial dental laboratories were surveyed for a total of 330 frameworks examined. Kennedy Class III (55%) was still the most common maxillary removable partial denture, although the frequency decreased. Kennedy Class I was the most common mandibular removable partial denture found. These differences may have been due to chance or possible changes in tooth loss and treatment selection. Bergman et al.[20] did a long-term follow-up consisting of 33 removable partial denture patients in Sweden. Two cases were Class II and a single case was Class III. Of the 30 Class I removable partial dentures, 25 were mandibular. Wetherell and Smales[21] conducted a survey in which, a total of 150 RPDs was thereby assessed. A distinct difference between maxillary and mandibular arches was seen. 60 out of 86 mandibular removable partial dentures were Class I. 29 Class II and 21 Class III maxillary removable partial dentures were found from the total of 64. Schwalm et al.[22] conducted a survey in which 161 patients were examining in which the Class I RPD was the most common followed by Class III, II, and IV, respectively. Keyf et al.[23] analyzed the distribution of partial edentulous patients who sought treatment for removable partial denture in clinics using Kennedy classification. This study showed Class I had a large distribution in the mandible, while class II in maxilla. In contrast to our study, Shinawi et al.[24] investigated the frequency of different patterns of partial edentulism in 200 patients in King Abdul Aziz University, showed that Kenney's class III was most predominant. Ashraf et al.[25] studied the prevalence of partial edentulism in South Indian rural population. The results of this study showed that Kennedy's class III was most prevalent in both maxilla and mandible. AL-Dwairi et al.[26] in a study investigated the frequency of different pattern of partial edentulism of 200 patients in Jordan. In this study, Kennedy's class III pattern of partial edentulism was most commonly encountered in both maxilla (47%) and mandible (45%). Sadig and Idowu[27] carried out a study in the Saudi population on 422 partially dentate patients in which they concluded that Kennedy's class III in both maxilla and mandible were common. Soomro et al.[28] in the study of partial edentulism based on Kennedy's classification carried out on 395 patients in Isra Dental College outpatient department in Hyderabad, showed that Kennedy's class IV was most prevalent in both arches. A study carried by Naveed et al.[29] at Armed Forces Institute of Dentistry, Pakistan on 1000 partially edentulous patients showed that Kennedy's class III was the most common in maxilla (60.9%) and mandible (46.8%).

  Conclusion Top

The result of the distribution of various classes of Kennedy's classification is almost similar to most of the other studies. The higher frequency of posterior tooth loss is suggestive of a greater need to create the awareness in patients about oral hygiene maintenance and early restorative management of carious lesions. The higher frequency of class 4 in male patients requires emphasis on safety measures for trauma prevention and advances in esthetic dentistry.

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Conflicts of interest

There are no conflicts of interest.

  References Top

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[PUBMED]  [Full text]  
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  [Figure 1], [Figure 2], [Figure 3]

  [Table 1]


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