Do CAD/CAM dentures really release less monomer than conventional dentures?

Clinical Oral Investigations - Computer-aided design (CAD)/computer-aided manufacturing (CAM) dentures are assumed to have more favourable material properties than conventionally fabricated...     

Do traditional techniques produce better conventional complete dentures than simplified techniques?

OBJECTIVES: To compare the quality of conventional complete dentures fabricated with two different techniques. A randomized controlled clinical trial was conducted to compare traditional (T) and simplified (S) methods of making complete conventional dentures on patients' ratings of satisfaction, comfort and function at 3 and 6 months following delivery. The quality of the prostheses was rated by prosthodontists at 6 months. MATERIALS AND METHODS: One hundred twenty-two male and female edentulous individuals, aged 45-75 years, were randomly allocated into groups that received dentures made with either T or S methods. Following delivery, patients' ratings of several denture-related factors were measured using 100mm visual analogue scales, and denture quality was assessed by blinded prosthodontists using ratings on a validated quantitative scale. RESULTS: There were no significant differences between the two groups in patient ratings for overall satisfaction (3 months: mean T = 83 mm, mean S = 83 mm, P = 0.97; 6 months: mean T = 79 mm, mean S = 79 mm, P = 0.96) or in prosthodontists' ratings of denture quality (T = 66, S = 63; P = 0.38). CONCLUSION: These results show that the quality of complete dentures does not suffer when manufacturing techniques are simplified to save time and materials. Dental educators should consider these findings when re-designing prosthodontic training programs.     

Implant retained or conventional dentures, which give more patients satisfaction?

DESIGN: This was a randomised controlled trial (RCT) set in a dental hospital. INTERVENTION: The implant group (IG) had two implants placed in the interforaminal region of the lower jaw followed (after healing) by a denture fixed to the implants by a ball attachment mechanism. In the conventional dentures group (CG), dentures were constructed using conventional replacement denture techniques. Patients in the IG had conventional upper dentures made in the same fashion. OUTCOME MEASURE: The performance of the dentures was evaluated using an oral health impact profile (OHIP) and a denture satisfaction scale before treatment and 3 months post-treatment. RESULTS: Analysis was conducted on an intention-to-treat basis. Substantial improvements in oral-health-related quality of life and denture satisfaction were reported by both groups. There were, however, no significant differences post-treatment between the groups. Patients randomised to the IG who declined implants had significantly lower pretreatment OHIP scores and there were significantly greater pre-/ post-treatment change-scores for individuals who had implants compared with the change-scores of people who declined. CONCLUSIONS: There were no significant post-treatment differences between the groups, but a treatment effect may be masked by the intention-to-treat analysis. The pre-/ post-treatment OHIP change-scores were significantly greater for people receiving implants than for those who refused.     

Does the nature of the definitive impression material influence the outcome of (mandibular) complete dentures?

The effects of impression materials on the outcome of complete dentures are poorly understood. This double-blind cross-over randomized controlled trial investigated eleven adult edentulous patients. Each received a maxillary denture and three mandibular dentures (which differed only in the three materials used to record the definitive impressions). The three mandibular dentures were given in a random order. Patients' opinions of each denture were recorded using a Linear Analogue Scale. There was a statistically-significant difference between the outcome of the dentures constructed when zinc-oxide eugenol was used, this material being least favoured (p < 0.001). It would therefore appear that care should be exercised when selecting impression materials when constructing mandibular complete dentures.     

Do implant-supported dentures facilitate efficacy of eating more healthily?

Edentulous persons have poor diet quality demonstrating a need for dietary intervention. Implant-supported mandibular overdentures (IODs) have functional advantages over conventional dentures (CD), but whether they enhance the ability to eat more healthily following dietary advice is unknown.     

Is there a relationship between mandibular cortical bone thickness and orthodontic treatment time?

ObjectivesTo determine whether there was a correlation between patients'' bone thickness and time spent in orthodontic treatment. The secondary aim was to study the influence of Angle classification, extraction treatment, and age on overall treatment duration.Materials and MethodsIn this retrospective study, records of 971 orthodontic patients from two centers were reviewed and 500 subjects were included after imposing inclusion/exclusion criteria. The Mental Index was used to determine patients'' bone density. For the Mental Index, a line perpendicular to the inferior border of the mandible was drawn on a panoramic radiograph so that it intersected the inferior border of the mental foramen. The mandibular cortical thickness was measured along this line. Two-sample t-test or a chi-square test, followed by multiple linear regression, were used to identify the factors affecting treatment duration.ResultsMandibular cortical thickness was negatively associated with treatment time for all subjects (P < .05). After adjusting for covariables, it remained significant for center-1, but non-significant for center-2 subjects. Angle Class II and Class III malocclusion, extraction therapy, and age had significant positive correlations with treatment duration (P < .05).ConclusionsThere is a negative correlation between the mandibular cortical thickness and orthodontic treatment duration. An extraction treatment plan and treatment of Angle Class II and Class III malocclusions significantly increase the duration of orthodontic treatment. Additionally, patients over 12 years of age have shorter treatment times compared to patients under 12 years of age.     

Is the mandibular third molar a risk factor for mandibular angle fracture?

OBJECTIVES: The objective of this study was to evaluate the association of mandibular angle fractures with the presence and state of the eruption of the mandibular third molar (M3). METHODS: The medical records and panoramic radiographs of 615 patients with mandibular fractures were examined. The presence or absence and degree of impaction of the M3 were assessed for each patient and related to the occurrence of fracture of the mandibular angle. Data were also collected for age, sex, mechanism of injury, number, and location of mandibular fracture. Data were analyzed by a chi-square statistic test and Student t test. RESULTS: The incidence of mandibular angle fracture was found to be significantly greater when an unerupted M3 was present (P <.05). Of the 426 patients with an M3, 127 (29.8%) had angle fractures. Of the 189 patients without an M3, 25 (13.2%) had angle fractures. CONCLUSIONS: The results of this study showed that the mandibular angle that contains an impacted M3 is more susceptible to fracture when exposed to an impact than an angle without an M3.     

Does a mandibular RDP and new maxillary CD improve masticatory efficiency and quality of life in patients with a mandibular Kennedy class I arch?

Objectives

To evaluate the change in masticatory efficiency and quality of life of patients treated with mandibular Kennedy class I removable partial dentures (RPDs) and maxillary complete dentures at the Department of Dentistry of the Federal University of Rio Grande do Norte.

Materials and methods

A total of 33 Kennedy class I patients were rehabilitated with maxillary complete dentures, and mandibular RPDs were selected for this non-randomized prospective intervention study. The patients had a mean age of 59.1 years. Masticatory efficiency was evaluated by colorimetric assay using fuchsin capsules. The measurements were conducted at baseline and 2 and 6 months after prosthesis insertion. Quality of life was evaluated using the Oral Health Impact Profile (OHIP-14) at baseline and 6 months after denture insertion. The Kolmogorov-Smirnov normality test was applied. Masticatory efficiency was evaluated by repeated measures ANOVA. Oral health-related quality of life was compared using the paired t test.

Results

There was no statistically significant difference in masticatory efficiency after denture insertion (p?=?0.101). Significant differences were found (p?=?0.010) for oral health-related quality of life. A significant improvement in psychological discomfort (p?<?0.01) and psychological disability (p?<?0.01) was observed. Mean difference value (95 % confidence interval) was 6.8 (3.8 to 9.7) points, reflecting a low impact of oral health on quality of life, considering the 0–56 range of variation of the OHIP-14 and a Cohen’s d of 1.13.

Conclusion

According to the results of the present study, rehabilitation with Kennedy class I RPDs and complete dentures did not influence masticatory efficiency but improved oral health-related quality of life.

Clinical relevance

The association between the patient’s quality of life and the masticatory efficiency is important for treatment predictability.

     

Paediatric mandibular fracture—a diagnostic challenge?

The purpose of this study was to clarify the frequency of missed mandibular fractures and to identify possible predictive factors for missed diagnosis. This was a retrospective study that included patients <20 years of age with a recent mandibular fracture. The outcome variable was missed mandibular fracture, which was determined when a fracture was not suspected or diagnosed during the patient’s first assessment in primary healthcare. The primary predictor variable was age group (i.e. children <13 years or teenagers/adolescents aged 13–19 years). The explanatory variables were sex, mechanism of injury, and type of facial facture. Other variables were clinical symptoms and findings. Mandibular fracture was missed at first contact in 27 of 182 patients (14.8%). Fracture was missed significantly more often in patients <13 years than in older patients (33.3% vs. 8.8%, P < 0.001). The only significant symptom or clinical finding that was associated with missed fractures was skin wound of the jaw (P = 0.009). There was no association between missed fracture and sex or mechanism of injury. Mandibular fractures in children are often missed at the first healthcare contact. Careful examination is necessary in paediatric mandibular injuries, particularly in the youngest age groups. Consultation should be smooth between paediatric trauma units and maxillofacial surgeons.     

Does fixation method affects temporomandibular joints after mandibular advancement?

Purpose

Sagittal split ramus osteotomy (SSRO) is a standard procedure in which miniplates and screws are used to achieve stabilization. Although the titanium plate and screw fixation system is stable, resorbable fixation systems are also used. There is currently no consensus on the ideal fixation technique for SSRO procedures and its effect on the condyle. We aimed to evaluate the stress distribution on temporomandibular joints (TMJ).

Dentistry a second time?

Introduction: Dentistry in Jordan is an attractive profession due to the high social standard it provides. This study aimed to investigate whether dentists would choose dentistry again and whether their professional expectations would change after years of practice. Of special interest were possible differences according to gender, age, degree and place of work. Methods: A self‐completion questionnaire was filled by a stratified random sample of 355 dentists in Jordan using closed questions. The questionnaire included professional, social and economic factors that influenced people’s choice of dentistry and whether they would choose it again and the reasons for that. Results: The results showed that 52% of dentists who returned the questionnaire had dentistry as their first choice; the most important determining factor was the dentist’s grades in the general secondary education. Fifty‐two per cent stated that they would not choose it for the second time, the main reason being the health problems acquired through the profession and the low income. Helping others and the social standard dentistry provides were the main reasons given for dentists to choose dentistry again. Conclusion: We report that more than half of the dentists included in this study would not ‘choose dentistry again’ as their profession regardless of age, gender and degree. This is mainly due to health problems acquired and the low income. We found that job satisfaction is highly affected by the workplace, and that more females are dissatisfied by the profession. This suggests that cultural background strongly affects the career decision.     

Tracheostomy tape: more trouble than it's worth?

In many units where microvascular free-tissue transfer in the head and neck region is practised, tracheostomy is completed with the suturing of the tube in place and the removal of the supporting struts from the tube flange. The thinking is that in removing the struts the risk of occlusion of the vascular pedicle of the free flap, as it lies in the neck, is reduced as the cervical tape cannot be applied. The evidence base for vascular obstruction resulting from a correctly positioned tape is lacking. Presented here is a case in which potential flap failure, as a result of a cervical tracheostomy tape, was avoided by early detection of ischaemia using microdialysis.     

Masticatory function of conventional complete denture wearers changing to 2-implant retained mandibular overdentures: clinical factor influences after 1 year of function

Purpose

Evaluate how clinical factors related to conventional complete denture (CCD) wearers, can influence masticatory function (MF) of totally edentulous patients before and after one-year transitioning to implant-retained mandibular overdentures (IMO).

Does oral contraceptive use affect the incidence of complications after extraction of a mandibular third molar?

OBJECTIVE: This study investigated whether oral contraceptive use affects the incidence of complications (pain, trismus, dry socket) in women undergoing removal of impacted mandibular third molars. PATIENTS AND METHOD: Two hundred and sixty seven women, aged 17 - 45 years, underwent removal of an impacted mandibular third molar. Eighty seven of the women were regular users of oral contraceptives. All patients were evaluated for postoperative pain, trismus and dry socket (localized alveolar osteitis). RESULTS: Mean trismus values (measured as maximum interincisal distance) were similar in the two groups of patients. Postoperative pain was significantly more frequent among women taking contraceptives, both on day 1 (30% of women taking contraceptives used analgesics, versus 11% of women not taking contraceptives, p < 0.001) and on day 5 (14% versus 5%, p = 0.024). Similarly, dry socket occurred more frequently among women taking contraceptives than among women not taking contraceptives (11% versus 4%, p = 0.017). CONCLUSIONS: The results of this study support the view that oral contraceptive use favours the appearance of dry socket and postoperative pain after extraction, but has no effect on trismus.     

Does long‐term use of unstable dentures weaken jaw muscles?

Summary Although it is well known that conventional denture wearers have lower maximum bite forces than dentate subjects, no previous studies have compared the strength of the jaw muscles between these two groups. This study compared maximum bite forces, electromyographic (EMG) activity and estimated jaw muscle strength among three groups: (i) 17 edentulous subjects using newly acquired implant‐retained overdentures (seven men, 10 women; mean age 60·3 ± 13·0 years); (ii) 10 age‐matched, fully dentate subjects (five men, five women; mean age 57·9 ± 11·0 years); and (iii) 39 young, fully dentate subjects (19 men, 20 women; mean age 24·4 ± 3·5 years). Electromyographic activity was recorded from subjects’ bilateral superficial masseter and anterior temporalis muscles while they generated maximum voluntary bite forces at the right central incisor, right first premolar and right first molar positions. Jaw muscle strength was estimated as the ratio of average EMG activity for all four muscles to the maximum bite force. At all three bite positions, edentulous subjects produced maximum bite forces that were less than half that of dentate subjects. Edentulous subjects also produced significantly less EMG activity and had significantly lower estimated jaw muscle strength. Our results suggest that weakened jaw muscles are one factor contributing to lower maximum bite forces among users of conventional dentures.     

Does a mandibular access osteotomy improve survival in pT2 oral tongue cancers? Retrospective study at a single institution

The surgical approach to the resection of oral tongue cancers can involve transoral resection (TOR) or a temporary mandibulotomy access (TMA). There are no relevant guidelines, and the oncological safety of TOR needs consideration. The objective of this study was to investigate TMA and TOR in pT2 oral tongue cancer surgery with regard to cancer outcomes. Demographic, surgical, and histology data from primary pT2 tongue cancers were recorded and evaluated through multivariate Cox regression for local recurrence (LR), disease-free survival (DFS), and overall survival (OS). A total of 166 patients with pT2 primary oral tongue cancer fulfilled the inclusion criteria; TOR was used in 95 patients and TMA in 71 patients. The minimum follow-up was 29 months. Group comparisons showed a significantly higher frequency of perineural spread (P = 0.013) in the TMA group; a higher frequency of involved margins on initial resection was seen in TOR patients (P = 0.010). Adjuvant postoperative radiotherapy was preferred in the TMA group, in line with the high pN positive status. Multivariate Cox regression showed significantly higher LR and lower DFS in the TOR group despite stratification of the major prognostic factors. The 5-year survival rate was reduced to 82.2% in the TOR group, while it remained constant at 93.0% in the TMA group. TMA provided superior local control and DFS compared to TOR in pT2 tongue cancers.