Prolonged Missing Of Molar Teeth And Risk Of Temporomandibular Joint Disorders

Introduction:Disharmony of the occlusion repeatedly applied over a long period of time could disturb the relation between the cranium and the condyle which may increase risk of Temporomandibular Joint Disorder (TMD).Aim:The aim of this study was to determine the relations between prolonged missing of molar(s)(PMM), third molars were excluded, and the TMD. Furthermore, the clinical findings were compared with the reading of the radiological imaging.Patients and methods:The current study consisted of120participants,40of them were complained from TMD and included as study group (SG),20patients of them were diagnosed by MRI and the other20patients were diagnosed by CT scan and Arthography. Meanwhile, the control group (CG) included80asymptomatic volunteers. Both SG and CG were subdivided into three subgroups which were:(1) prolonged missing of first and/or second molar (PMM) subgroups that included individuals that have missing of first and/or second molar for ten years or more;(2) recently missing molar (RMM) subgroups, including individuals that have missing of first and/or second molar for a period of less than ten years; and (3) no missing molars (NMM) subgroups, including individuals that firsts and seconds molar teeth were preserved. Our study were concentrated on PMM of both SG and CG, therefore PMM of SG&CG were checked for missing of first and/or second, maxillary and/or mandibular molars, after that a comparative study were applied and again were subdivided into five pairs (each pair of group was one of SG were compared with its Counterpart of CG) as the following:1. PMM of SG..............(Compared with).....PMM ofCG.2. PM of16&(or)26of SG.(With) PM of16&(or)26of CG.3. PM of17&(or)27of SG.(With) PM of16&(or)26of CG.4. PM of36&(or)46of SG.(With) PM of36&(or)46of CG.5. PM of37&(or)47of SG.(With) PM of36&(or)46of CG. Data analysis:Paired-Sample t Test was applied to the data of the PMM of SG and CG to test for statistically significant (P-value>.05) of the relation between the five pairs SG and CG.Results:The age range of the SG was16-63years with a mean of38.32years,11participants were males and29were females.Out of40symptomatic patients, a.15(37.5%) there age were15-30years, b.14(35%)31-45years, c.11(27.5%) more than45years.Age range of the CG was19-64years with a mean of40.38years,20participitants were males and60were females. Ten out of twelve patients of temporomandibular joint (TMJ) clicking were with internal derangement (ID), therefore there is a relation between TMJ clicking and ID.1. Study group total number of the patients.a. NMM (70%)28patients.b. PMM (20%)8patients.c. RMM4patients (10%).2. Control group total number of the volunteers.a. NMM (82.5%)66volunteers.b. PMM (5%)4volunteers.c. RMM (12.5%)10volunteers.The current study was concentrated on PMM.I. SG8out of40(With) CG4out of80(P=.044).II. Missing of maxillary first molar(s). SG2out of36(With) CG2out of70(no Correlation).III. Missing of maxillary second molar(s). SG1out of36(With) CG0out of70(P=.324).IV. Missing of mandibular first molar(s). SG6out of36(With) CG1out of70(P=.023).V. Missing of mandibular second molar(s) SG1out of36(With) CG3out of70(P=.160).Conclusions:missing of molar teeth for ten years or more may contribute to TMD. Furthermore, the effect of prolonged missing of mandibular first molar(s) may increase the contribution to TMD. It seems that females were more affected by TMD than males. In addition, individuals with age of (15-45) years appeared to be more susceptible for TMD than other age groups. Finally, the current study emphasizes that clicking is an important sign in the diagnosis of internal derangement of the Temporomandibular Joint.