“BY THEIR TEETH YOU SHALL KNOW THEM”: PROSTHODONTIST’S PERCEPTION OF THE CONTRIBUTION OF TOOTH LOSS TO HEALTH
(An inaugural lecture)
Professor Oluwole Oyekunle Dosumu
Department of Restorative Dentistry
Faculty of Dentistry
University of Ibadan
This lecture highlights the causes and consequences of tooth loss (edentulism), the management of some challenging cases and the role of the teeth in the identification of an individual. Extensive literature review has revealed that the main factors responsible for tooth mortality generally, are caries and periodontal disease which also shows a wide geographical and cultural variation between different populations. Other reasons include trauma, impaction, prosthetic consideration, orthodontic reasons, neoplasia and behaviour such as smoking.
Juvenile (Aggressive (Ag)) periodontitis which is a variant of periodontal disease in adolescents is characterized by severe alveolar bone loss, pronounced loss of periodontal attachment and subsequent tooth loss. Also, rampant caries which is a lesion of acute onset involving many or all of the erupted teeth involving the deciduous and permanent teeth in children was found to be a commoner cause of tooth loss in children.
Tooth loss can also be congenital as in ectodermal dysplasia with characteristic feature of anodontia or hypodontia while oligodontia is a developmental defect characterized by the absence of six or more permanent teeth.
In South West Nigeria, the prevalence of total edentulism in the age group 36 years and over was 1.5% with male to female ratio of 2:1 and it is closely associated with socioeconomic-educational factors which is more prevalent in poor populations and women.
Consequent to loss of tooth/teeth without replacement over a considerable length of time, the teeth abutting and opposing the empty gap/space drift, over-erupt, tilt and are mal-aligned which present problems of malocclusion, premature contacts, increased inter-dental spacing, more food packing between the created space, more plaque accumulation, caries, gingival and periodontal infections and may further cause more loss of teeth resulting in aesthetic derangement.
Furthermore, the alveolar bone previously supporting the lost teeth become rapidly lost and gradually continues as an ongoing process, affecting the mean ratio of anterior mandibular residual ridge resorption (RRR) four times more than the anterior maxillary RRR. This further affects occlusal vertical face height and facial appearance. Most studies agree that complete denture wearers have only about one fifth to one-fourth the bite strength and masticatory force of dentate individuals and require 7 times more chewing strokes than those with natural dentitions to be able to cut food into half of its original size. The thickness of the masseter muscle was reported to decrease in edentulous patients, thereby decreasing the bite force which may partly explain why individuals wearing complete dentures have difficulty chewing hard foods.
Edentulism can be accompanied by functional and sensory deficiencies of the oral mucosa, oral musculature, and the salivary glands. It may induce an oral dyskinesia (abnormal, involuntary, patterned or stereotyped, and purposeless orofacial movements) and tardive dyskinesia, a type of dyskinesia occurring among patients chronically treated with antipsychotic drugs.
Tooth loss can lead to loss of confidence, limitation of food choice, reduction in enjoyment of food, avoidance of laughing in public, inability to accept change in facial shape and reluctance to form close relationships, sadness, depression, feeling of losing body part, and feeling of aging. The number of patients that failed to come to terms with their tooth loss indicates that the effect of tooth loss on self-esteem and self image is not as short lived as has been assumed.
It can also lead to a higher prevalence of obesity, and eventually increase risk of cardiovascular diseases and gastrointestinal disorders, increased rates of chronic inflammatory changes of the gastric mucosa, upper gastrointestinal and pancreatic cancer, and higher rates of peptic or duodenal ulcers, risk of noninsulin-dependent diabetes mellitus, risk of electrocardiographic abnormalities, hypertension, heart failure, ischemic heart disease, stroke, and aortic valve sclerosis, decreased daily function, physical activity, and physical domains of health-related quality of life, risk of chronic kidney disease, sleep-disordered breathing, including obstructive sleep apnea. Another study established that total tooth loss was associated with low citrus fruit consumption, low plasma vitamin C levels, increased amounts of inflammatory reactants, such as plasma C-reactive protein and increased levels of plasma interleukin-6, fibrinogen, and factor VIII in women which are factors associated with an increased risk of coronary heart diseases and stroke. Another study associated edentulism with a weight gain of >5% in one year and an association between edentulism and obesity was found in several studies.
Regarding life expectancy of edentulous individuals, tooth loss was reported to be associated with the onset of disability and mortality, even after adjusting for confounding factors such as socioeconomic and health behaviour factors.
Teeth have an important role in facial appearance, speech, and eating ability and there is overwhelming evidence showing the negative effect of edentulism on OHQoL as it negatively influences not only oral function, but also social life and day-to-day activities. Documentation from the literature established the association of teeth arrangement with facial appearance (beautiful or ugly), the malnourished, the healthy or the unhealthy and the dead man.
On the other hand, dentures could improve oral appearance and social interactions of individuals, which might enhance self-esteem and thus contribute to psychological well-being which I achieved in the course of the management of my patients including the very challenging cases.