Background: Periodontitis is an inflammatory condition affecting the tooth-supporting tissues. It contributes extensively to the global burden of oral diseases. The mild-to-moderate periodontitis is the most common, with prevalence estimates ranging from 13% to 57%, depending on the sample characteristics and the case definition used. Studies in Middle Eastern countries showed that the prevalence of periodontitis tends to be low, around 13%. However, in the Sultanate of Oman, only studies surveying caries in children have been conducted. There are no published studies surveying the oral health status of an adult population.
Perceptions of oral health and positive or negative impacts of oral health status on the quality of life cannot really be recorded and must be reported by those who experience the conditions. These perceptions can be characterised by measures of Oral-Health-Related Quality of Life (OHRQoL). Several instruments have been developed to measure OHRQoL. Of these, the most extensively studied and widely used instrument is the Oral Health Impact Profile (OHIP). Only a few observation studies have reported on the impact of periodontitis on OHRQoL. While most of these have shown an association between periodontitis and poor quality of life, many did not allow for the concurrent impact of other oral diseases and conditions on OHRQoL, meaning that the periodontitis-OHRQoL association may have been confounded.
Objectives: The objectives of this study are to: (1) describe the oral health status of Omani teachers in the Muscat region, (2) test the validity of the short-form Arabic version of the OHIP in Oman (3) investigate the impact of periodontal diseases on the OHRQoL; and determined whether a biological gradient exists between the disease and OHRQoL.
Methods: This is a cross-sectional study of 319 teachers who were randomly sampled from the Muscat region schools’ list of teachers in Oman. The teachers were systematically examined for dental caries, tooth loss, and periodontal attachment loss. OHRQoL was measured using the 14-item Arabic OHIP questionnaire (OHIP-14A). The questionnaire also collected data on each study member’s socio-demographic characteristics, dental care characteristics, self-rated general and oral health, self-rated periodontal status and self-rated wellbeing. Socio-economic status (SES) was determined from each individual’s household income.
Results: The age of participants ranged from 23 to 50, with a mean age of 30.9 years (sd = 5.3). There were similar proportions of males and females, and almost half of the participants were in the 20 to 29 years age group.
An average of 156 sites were examined per participant. Around 40% of participants had at least one site with gingival recession (GR) of 2+mm, and almost all had at least one site with PD or CAL of 3+mm. More than one-third (36%) of participants had at least one site with 5+mm clinical attachment loss (CAL), and one in ten (12%) had at least one site with 6+mm CAL. For pocket depths (PD), those estimates were 26% and 8%, respectively. A gradient by age group was evident across the different thresholds. Around 6% of sites had some GR; one site in six had 3+mm PD; and one site in five had 3+mm CAL. Only 23% of the participants had had previous periodontal treatment.
Only 22 (7.0%) of the participants were caries-free. The number of decayed teeth ranged from 0 to 12. The mean DMFT was 6.3 (sd = 4.2), with two out of three participants having at least one decayed tooth. Females had higher DMFT and FT scores than males, on average, and there was a significant age gradient in mean DMFT, MT and FT. Almost one-third of participants had three or more teeth missing due to caries; this was slightly higher among females. Episodic dental visitors (those visiting only with a problem or pain) had fewer sound teeth and more missing or decayed teeth, and higher DMFT scores overall.
In the OHIP-14A questionnaire, the majority of responses were 'never' or 'hardly ever' for most domains. On average, the extent of overall OHIP-14 was 1.2 (sd = 1.4). The mean OHIP score was 14 (sd = 8.0). The highest subscale scores were those pertaining to psychological discomfort.
There were no significant differences in the prevalence, extent or severity of impacts of OHIP-14 total score by periodontal status. Moreover, there were no statistically significant associations between periodontal status and self-reported general or oral health.
In the multivariate models, no association was observed between periodontal attachment loss and either the prevalence of OHIP-14 impacts or the mean OHIP-14 score. On the other hand, there was a statistically significant association between DMFT and one or more OHIP-14 impacts. Tooth sensitivity, stress level and DMFT were associated with the mean OHIP-14 score.
Conclusion: The study showed that dental caries experience was moderate, and the prevalence, extent and severity of periodontitis was higher than estimates reported from industrialised countries such as Australia, New Zealand and the USA. Moreover, the OHIP-14A was shown to have acceptable validity and can be recommended for use in an adult population in Oman. Contrary to most previous studies, there was no association between periodontitis and OHRQoL, irrespective of whether the OHIP-14A or global self-reported general or oral health status was used to represent the latter.
