Relationship among malocclusion, number of occlusal pairs and mastication

Association between masticatory performance and oral conditions in adults: A systematic review and meta-analysis

OBJECTIVES

To give an overview of the evidence on the associations between oral condition factors and masticatory performance of adults, and to evaluate the direction and level of the associations.

DATA/SOURCES

Medline (PubMed), Embase (Ovid) and CINAHL Plus (EBSCOhost) were searched up to May 2022 for cross-sectional studies on oral conditions and masticatory performance in adults. Methodological quality of the included studies was independently evaluated based on the Joanna Briggs Institute critical appraisal checklist for analytical cross-sectional studies. Data on the associations between oral condition factors and masticatory performance were extracted. Meta-analysis was conducted on correlation coefficients.

STUDY SELECTION

Of the 8,035 records identified, 97 articles (88 studies) were included in the qualitative synthesis, and 18 studies were included in the meta-analyses. Among the oral condition factors that had associations with masticatory performance, the number of natural/remaining teeth or functional tooth pairs was reported by the largest number of studies, followed by perioral muscle status, dental prosthetic status, oral moisture status and periodontal status. Results of the meta-analyses showed that the positive association with the number of natural/remaining teeth was the strongest (pooled correlation coefficient: 0.51, 95%CI: 0.48 to 0.54), followed by the number of functional tooth pairs, maximum tongue force/pressure, while the association with the oral moisture status was the weakest.

CONCLUSIONS

Number of natural/remaining teeth and functional tooth pairs, perioral muscle status, oral moisture status, dental prosthetic status and periodontal status are the main oral condition factors influencing masticatory performance. Based on the limited evidence available, among these factors, the number of natural/remaining teeth has the strongest positive association, with a very low quality of evidence.

CLINICAL SIGNIFICANCE

This study provides valuable information on the oral condition factors associated with masticatory performance, which would be important for policymakers and clinical practitioners when deciding on the strategies for improving the masticatory performance of adults. This review highlights the need for standardization of measures and classifications of masticatory performance and oral conditions.

REGISTRATION

PROSPERO (registration number: CRD42021256824).

Masticatory behaviour and chewing difficulties in young adults with temporomandibular disorders

BACKGROUND

Difficulties and limitations on masticatory function are among the main reasons why patients with temporomandibular disorder (TMD) seek care.

OBJECTIVE

To evaluate the masticatory behaviour and perception of chewing difficulties in adults with mild TMD of recent onset, considering the presence of malocclusion.

METHODS

Eighty-one young adults were divided into groups according to the presence of TMD and malocclusion: Non-TMD Normal Occlusion (n = 18), Non-TMD Malocclusion (n = 22), TMD Normal Occlusion (n = 18) and TMD Malocclusion (n = 23). TMD was assessed using the TMD Research Diagnostic Criteria and volunteers also answered questionnaires regarding their perception about jaw functional limitation and difficulty to chew foods of different textures. Masticatory and swallowing behaviours were assessed using the Orofacial Myofunctional Evaluation with Scores (OMES) protocol. Chewing time and chewing frequency taken to ingest the test-food were also obtained. Two-way-ANOVA was used to analyse the TMD, occlusion and TMD × occlusion interaction effects.

RESULTS

Temporomandibular disorder effect was observed on vertical jaw mobility and jaw function limitation total scores, meaning that groups differed in the perception of opening limitation and mandibular limitation according to TMD status with a medium effect size. Also, more changes in chewing function (OMES-chewing score) and higher chewing frequency was observed in the presence of TMD (P < 0.05). Occlusion effect was only observed on OMES-swallowing score and no TMD × occlusion interaction effect was observed.

CONCLUSION

Changes in chewing behaviour, frequency and perception of mandibular limitation was observed in the presence of TMD, pointing out the importance of functional evaluation when planning and establishing a treatment plan.

Occlusal, chewing, and tasting characteristics associated with orofacial dysfunctions in children with unilateral cleft lip and palate: a case-control study

OBJECTIVE

The objective of this study is to assess the associations between orofacial dysfunctions with malocclusion, masticatory performance, and taste in children with and without unilateral cleft lip and palate (UCLP).

MATERIAL AND METHODS

A patient-based, matched, case-control study was conducted involving 108 8- to 10-year-old children divided in UCLP and control groups. Orofacial dysfunctions were evaluated using the Nordic Orofacial Test-Screening (NOT-S). Orthodontic treatment need was evaluated using the Goslon Yardstick Index (GYI) and the Index of Orthodontic Treatment Need (IOTN) of patients and controls, respectively. Masticatory performance was assessed using a chewable test material to determine median particle size (X ₅₀) and distribution of particles in different sieves (b value). Taste perception was evaluated using four solutions (sweet, salty, bitter, or acid) in three different concentrations.

RESULTS

More than half of the patients needed orthodontic surgery. UCLP group presented higher median particle size and needed more chewing cycles to comminute the artificial test into particles smaller than the median than those of controls. UCLP group had less perception of salty flavor than controls. There was a positive correlation between b value and NOT-S examination score for patients. In regression analysis, a significant interrelationship was observed between NOT-S examination score and b value.

CONCLUSIONS

In the UCLP patients, masticatory performance was compromised probably as a result of facial asymmetry and speech disturbance; whereas, taste was less perceived only for salty flavor.

CLINICAL RELEVANCE

These findings provide preliminary evidence that mastication and taste are altered in children with UCLP, so these factors must be followed up to ensure oral and general health in growing individuals.

Assessment of masticatory performance, bite force, orthodontic treatment need and orofacial dysfunction in children and adolescents

OBJECTIVES

Few studies have evaluated the relationship between morphological and functional characteristics of the masticatory apparatus in young subjects. Thus, the aim of this study was to evaluate masticatory performance (MP), maximal bite force (BF), orthodontic treatment need and orofacial dysfunction in children and adolescents.

DESIGN

The sample consisted of 316 subjects of both genders, with an age range 6-16years divided into 4 groups: early mixed, intermediate mixed, late mixed and permanent dentition. MP was evaluated by the individual's ability to comminute a chewable test material in order to determine median particle size (X(50)) and distribution of particles in different sieves ("b"). BF was determined using a digital gnatodynamometer with fork strength of 10mm. Orofacial function and orthodontic treatment need were screened using the Nordic Orofacial Test-Screening (NOT-S) protocol and Index of Orthodontic Treatment Need (IOTN), respectively. The results were submitted to descriptive statistics, normality test, analysis of variance and stepwise multiple linear regression to test relationship between MP and studied independent variables.

RESULTS

Variance of X(50) and b between groups was statistically significant. But evaluation of variables that significantly contributed to MP variation showed that age, body mass index (BMI), BF and the presence of sleep bruxism were negatively related to X(50) and the NOT-S clinical exam scores showed a positive relationship with X(50).

CONCLUSION

In the studied sample, age, BMI, BF and the presence of sleep bruxism were related to better MP; but the increase in NOT-S scores was significantly related to poorer MP.