HRT and tooth loss [Jan 2001; 83-4]

HRT and tooth loss
Review Results Dental outcomes Economic analysis Comment Reasons for giving hormone replacement therapy to postmenopausal women are fairly well known. Around the menopause it is to do with control of symptoms, especially flushing. Later it is to more to do with protecting bone density to prevent osteoporosis and later fractures. One of the unintended consequences is the protection of teeth.

The arguments that protection of teeth is a real phenomenon are several, if predominantly indirect. Osteoporosis affects jaw bones as much as long bones and the spine. Loss of mineral from the area surrounding the teeth leads to tooth loss. Women with low bone mineral density in spine and hip bones have fewer teeth than those with higher bone density. A systematic review [1] seeks to pull together several links in the chain of evidence linking tooth loss and HRT, and to quantify the economic effects.

Review

The review used MEDLINE, other databases and manual searches for the period from 1980 to 1998. Eligible studies were full published papers of any study design of a minimum of three months looking at postmenopausal women and with a minimum of 10 patients per study arm. Only English language papers were used.

Subjects eligible were postmenopausal women receiving HRT or not and those with documented osteoporosis. Outcomes used were dental outcomes (predominantly use of dentures, number of teeth, or percentage edentulous), and HRT use.

Results

Dental outcomes

Twenty studies were eventually included, with 13,700 women with the eligibility and outcome criteria fulfilled. The main dental results are shown in the Table. For all postmenopausal women, with a mean age of 67 years, there was denture use in just under half (47%). In women who had not used HRT, this rose to 69%, but fell to 27% for those with a history of HRT use. Women with a history of HRT use had more teeth than those who had not used HRT.

Table: Dental outcomes in women, and the effect of hormone replacement therapy (HRT)

Dental outcomes and HRT
Women	Number of studies	Number of women	Mean age (years)	Percent with dentures (CI)	Number of remaining teeth (CI)
All women	10	5757	67	47 (44)	20 (8)
HRT	4	2881	69	27 (28)	22 (7)
No HRT	8	2073	69	69 (43)	16 (7)
Osteoporosis	3	203	68	73 (68)	5 (10)
No osteoporosis	3	112	68	69 (78)	6 (10)

The information on dentures and number of teeth in women with and without documented osteoporosis was limited to a few hundred women, and was not informative.

Economic analysis

Economic analysis used published costs of dental procedures (fillings, crowns, root canals, extractions, X-rays dentures) using US and UK costs to give a range of costs expressed in US$. The high and low costs were used to estimate a range of likely costs, and these were applied to a hypothetical cohort of 1000 women who were and were not HRT users, and these costs were applied to high and low estimates for full or partial dentures or tooth extractions. The period assumed HRT use for five years, which was the mean duration in the studies in the review.

The excess cost of dental treatment associated with 1000 non-HRT users ranged from $14,000 (£10,000) to $300,000 (£214,000), with a mean of about $100,000 (£71,000). This means that use of HRT saves about £71 a year on average in dental treatment for each woman treated.

Comment

Bandolier is old enough to remember when complete removal of teeth was seen as a useful 21 ^st birthday present, or even as a wedding present for a blushing bride. How things change. Perhaps the effects of HRT on tooth retention are well known. The evidence from studies is limited, indirect (no randomised trials with this as the main outcome), and with different outcomes. Yet by pulling together evidence from different sources, and by doing some not very sophisticated analysis, the conclusion that HRT use prevents costs elsewhere begins to stand up.

It is a sort of unexpected consequence of HRT use. It benefits the system, and also women who otherwise might have to spend more time in the dentist's chair, and be concerned about their appearance. Seventy years is not old for a woman, and retention of teeth may well bring even more unexpected additional benefits stemming from confidence and a refusal to be old.

References:

IE Allen et al. Effect of postmenopausal hormone replacement therapy on dental outcomes: systematic reviews of the literature and pharmacoeconomic analysis. Managed Care Interface 2000 13: 93-99.

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