Changes in the Oral Cavity

IgG฀antibody฀levels,฀indicative฀of฀an฀immunosuppressive฀effect฀ [205] .฀In฀addition,฀nicotine฀has฀ been฀reported฀to฀inhibit฀the฀proliferation฀of฀osteoblasts฀in฀vitro฀ [206] ฀and฀to฀reduce฀the฀gingival฀ circulation฀ [207] ,฀although฀these฀indings฀need฀to฀be฀conirmed฀in฀further฀investigations. Increased฀plaque฀formation฀is฀a฀proven฀inding฀among฀smokers฀ [208] ,฀and฀this฀leads฀to฀ increased฀bacterial฀colonisation฀of฀the฀oral฀cavity฀and฀gingival฀region฀ [209] ฀with฀all฀the฀ attendant฀consequences.฀Furthermore,฀melanosis฀of฀the฀tongue฀black฀hairy฀tongue฀and฀of฀ the฀ oral฀ mucosa฀ may฀ result฀ from฀ the฀ pigmentation฀ of฀ basal฀ keratinocytes฀ [210] .฀ These฀ changes฀are฀reversible฀on฀smoking฀cessation.฀As฀a฀result฀of฀the฀thermal฀insult฀of฀smoke,฀ pipe฀ smokers฀ often฀ display฀ stomatitis฀ or฀ smoker’s฀ palate฀ [211] ,฀ a฀ condition฀ that฀ may฀ undergo฀transformation฀to฀a฀precancerous฀lesion฀in฀rare฀cases. With฀a฀consumption฀of฀20฀cigarsday฀for฀13฀years,฀Sigmund฀Freud฀may฀serve฀as฀a฀typi- cal฀example:฀he฀developed฀leukoplakia฀with฀recurring฀oral฀cancers,฀for฀which฀he฀had฀to฀ undergo฀surgery฀on฀numerous฀occasions.฀Despite฀having฀to฀wear฀a฀prosthetic฀plate฀in฀his฀ upper฀and฀lower฀jaw,฀he฀continued฀to฀smoke฀persistently฀until฀his฀death. Smoking฀encourages฀discolouration฀of฀the฀teeth฀and฀abrasion฀especially฀in฀pipe฀smok- ers฀or฀users฀of฀chewing฀tobacco.฀In฀association฀with฀tooth฀loss,฀these฀changes฀ultimately฀ lead฀to฀occlusive฀disturbances฀ [211] .฀Such฀indings฀are฀encountered฀more฀frequently฀in฀the฀ USA฀ than฀ in฀ Europe,฀ particularly฀ since฀ 10–16฀ million฀ US฀ Americans฀ use฀ smokeless฀ tobacco฀as฀an฀alternative฀to฀smoking฀cigarettes฀ [212] . Compared฀with฀non-exposed฀children,฀children฀passively฀exposed฀to฀maternal฀smoking฀ are฀found฀to฀be฀at฀increased฀risk฀for฀the฀development฀of฀caries฀OR฀=฀1.54฀vs.฀1.06;฀p฀฀0.05฀ [213] .

7.3.3 Oral and Laryngeal Cancer

More฀than฀9฀out฀of฀10฀oral฀cavity฀cancers฀in฀men฀and฀6฀out฀of฀10฀in฀women฀are฀caused฀by฀ smoking,฀while฀alcohol฀has฀been฀identiied฀as฀the฀strongest฀additional฀risk฀factor฀ [214] .฀ Compared฀ with฀ non-smokers,฀ the฀ relative฀ risk฀ in฀ smokers฀ is฀ increased฀ by฀ 2-฀ to฀ 18-fold฀ [215] ,฀the฀increase฀being฀dependent฀on฀the฀number฀of฀cigarettes฀smoked฀daily฀ [216] .฀The฀ risk฀of฀cancer฀development฀declines฀just฀a฀few฀years฀after฀smoking฀cessation฀ [217] ,฀in฀one฀ study฀by฀50฀after฀3–5฀years฀of฀smoking฀abstinence฀ [216] .฀The฀eficacy฀of฀radiation฀therapy฀ in฀such฀tumours฀is฀considerably฀reduced฀where฀patients฀continue฀to฀smoke฀ [218] .฀Likewise,฀ 8฀out฀of฀10฀cases฀of฀laryngeal฀cancer฀are฀caused฀by฀cigarette฀smoking฀ [219] ,฀and฀the฀causal฀ relationship฀has฀been฀conirmed฀by฀numerous฀epidemiological฀and฀clinical฀studies฀ [220] .฀ The฀risk฀of฀laryngeal฀cancer฀is฀also฀associated฀with฀the฀number฀of฀cigarettes฀smoked฀ [220] .฀ For฀every฀incremental฀increase฀in฀pack-years฀of฀smoking,฀there฀is฀a฀small฀but฀measurable฀ increase฀in฀the฀odds฀that฀a฀patient’s฀laryngeal฀cancer฀will฀already฀be฀stage฀III฀or฀IV฀at฀initial฀ diagnosis฀ [221] .฀The฀bidi฀cigarettes฀commonly฀smoked฀in฀India฀constitute฀a฀particular฀dan- ger:฀ compared฀ with฀ non-smokers,฀ smokers฀ of฀ 20฀ bidi฀ cigarettesday฀ have฀ a฀ 12.68-fold฀ higher฀relative฀risk฀for฀laryngeal฀cancer฀ [222] . It฀has฀been฀suggested฀that฀the฀mechanisms฀underlying฀carcinogenesis฀are฀mediated฀by฀ acetaldehyde฀formed฀by฀alcohol฀and฀cigarette฀smoke,฀a฀process฀that฀is฀also฀encouraged฀by฀ microbial฀oxidation฀of฀ethanol฀by฀the฀oral฀microlora฀ [223] .฀The฀implications฀are฀especially฀ serious฀where฀smokers฀hand-roll฀their฀own฀cigarettes฀–฀a฀practice฀that฀is฀still฀customary฀in฀ some฀parts฀of฀the฀world฀see฀Table฀ 7.4 ฀and฀is฀also฀becoming฀increasingly฀common฀again฀ for฀inancial฀reasons฀in฀Germany.฀Contact฀with฀the฀uniltered฀smoke฀and฀its฀constituents฀ damages฀both฀the฀oral฀mucosa฀as฀well฀as฀that฀of฀the฀pharynx฀and฀larynx฀ [224] . The฀increased฀risk฀for฀laryngeal฀cancer฀associated฀with฀excessive฀alcohol฀intake฀has฀ been฀demonstrated฀in฀heavy฀drinkers฀and฀binge฀drinkers฀207฀ml฀pure฀alcohol฀or฀more฀ daily:฀the฀relative฀risks฀in฀these฀categories฀were฀9.6฀and฀28.4,฀respectively,฀compared฀with฀ 2.6฀in฀non-drinking฀smokers฀ [225] .

7.4 Disorders of Lipid and Glucose Metabolism

7.4.1 Lipid and Cholesterol Metabolism

Serum฀concentrations฀of฀triglycerides฀and฀total฀cholesterol฀are฀dependent฀in฀particular฀on฀ dietary฀habits,฀but฀also฀on฀genetic฀factors,฀body฀weight฀and฀alcohol฀consumption.฀Ex-smokers฀ often฀revise฀their฀diet฀to฀include฀more฀vegetable฀protein,฀and฀these฀new฀dietary฀habits฀restore฀ serum฀cholesterol฀and฀lipids฀to฀normal฀levels฀ [226] .฀When฀patients฀at฀increased฀risk฀of฀coro- nary฀heart฀disease฀were฀given฀brief฀behavioural฀counselling฀to฀implement฀lifestyle฀changes,฀ their฀odds฀of฀moving฀to฀actionmaintenance฀of฀behavioural฀intervention฀were฀improved,฀ compared฀with฀control฀patients:฀for฀example,฀fat฀reduction฀OR฀=฀2.15;฀CI:฀1.30–3.56,฀ increased฀physical฀activity฀OR฀=฀1.89;฀CI:฀1.07–3.36฀and฀smoking฀cessation฀OR฀=฀1.77;฀ CI:฀0.76–4.14฀ [227] . Most฀epidemiological฀studies฀ [228] ฀indicate฀that฀smokers฀have฀raised฀triglyceride฀con- centrations฀compared฀with฀non-smokers,฀a฀inding฀that฀has฀not฀been฀conirmed฀in฀long-term฀ Variables Manufactured฀cigarettes Hand-rolled฀cigarettes฀ Patients฀ Controls฀ Patients฀ Controls฀ Age฀years 40–49 5฀14.3 16฀22.2 8฀4.8 10฀6.2 50–59 11฀31.4 15฀20.8 48฀28.9 36฀22.2 60–69 15฀42.9 28฀38.9 80฀48.2 65฀40.1 70–79 4฀11.4 13฀18.1 30฀18.1 51฀31.5 Place฀of฀residence Rural 33฀94.3 67฀93.1 119฀71.7 97฀59.9 Urban 2฀5.7 5฀6.9 47฀28.3 65฀40.1 Education฀years 0–4 16฀45.7 41฀56.9 129฀77.7 124฀76.5 ³ 5 19฀54.3 31฀43.1 37฀22.3 38฀23.5 Total฀number฀of฀patients 35 72 166 162 Table 7.4 ฀฀฀Frequency฀distribution,฀by฀socio-demographic฀variables,฀of฀patients฀with฀cancers฀of฀the฀ oral฀cavity,฀pharynx฀and฀larynx฀compared฀with฀controls฀ [224]