TY - JOUR
T1 - The impact of residual ridge morphology on the masticatory performance of complete denture wearers
AU - Sta Maria, M. T.
AU - Hasegawa, Yoko
AU - Marito, Pinta
AU - Yoshimoto, Tasuku
AU - Salazar, Simonne
AU - Hori, Kazuhiro
AU - Ono, Takahiro
N1 - Funding Information:
The MP of denture wearers is influenced by many factors, such as tooth loss [13,17,18], residual ridge [1,9,13, 18–21], maximum bite force [ 15,17,22,23], the tongue [ 22,24], and lip function [2], salivary secretion [15,25,26], previous experience with dentures [15], and denture stability, and retention [9,15,21,27,28]. Among those factors, poor residual ridge (RR) morphology has always been a primary concern for clinicians hoping to achieve successful CD treatment because RR height and form are essential to support the denture and prevent dislodgment [21]. RR resorption leads to a decrease in the RR height [1,29], and the result is not only a decrease in the denture supporting areas but also a decrease in bracing and salivary retention [19]. In addition, the morphology of the RR is complex [1], and it has been pointed out that the morphology has a significant influence on the functional performance of dentures because the morphology of the RR is related to the stress distribution at the denture bearing areas [30]. In addition, in cases of upper and lower CD, the combination of RR morphology is expected to affect denture stability and, consequently, MP, but we have not found any studies reporting on this. The relationship between RR morphology and MP in CD patients has been shown in several papers [9,15,18,31,32]. On the other hand, in these reports, no studies examined contributory factors other than RR morphology that affect MP.When the RR remodels after tooth loss, not only it changes shape but also loses its height, making the maxillary arch appear narrower while the mandibular arch appears wider [37]. The atrophy rate of the mandible in CD wearers is higher than the maxilla due to the unfavorable shape and size of the RR on which mechanical load is applied during chewing [1]. The mandibular RR height is approximately four times lower than the maxilla's, making it less capable of resisting occlusal forces [37]. According to our study, the mandibular RR height significantly influenced the MP of CD wearers. This was supported by the results of the covariance analysis, indicating that the mandibular RR height had the strongest effect on the MP of CD wearers, followed by the combined RR forms and total occlusal contact area. This result was consistent with another study which found that patients with a normal mandibular RR height had a better MP than those with an RR resorption [15]. Their findings suggested that the mandibular RR height was strongly related to mandibular CD retention and stability, causing discomfort during the function and eventually affecting the MP [15]. On the contrary, our findings opposed those of previous studies, which found no significant relationship between RR height using panoramic radiographs and MP using the sieving method with peanuts [31,55].
Publisher Copyright:
© 2023
PY - 2023/5
Y1 - 2023/5
N2 - Statement of the problem: Morphology of the residual ridge (RR) is expected to influence the masticatory performance (MP) of complete denture (CD) patients, but considerable details of this relationship are unknown. Purpose: We aimed to investigate the association between the objective MP and RR morphology of CD wearers and other contributory factors affecting their MP. Materials and methods: Sixty-five patients with well-fitting upper and lower CDs with no complaints of pain were enrolled. The objective MP was measured using test gummy jelly and a fully automated measuring device. The RR form was divided into U-type, V-type, I-intermediate, and F-Flat, then combinations of upper and lower RR forms (combined RR) were classified. The height was measured using CD's denture basal surface replicas, while occlusal contact of CDs was assessed using a tooth contact analysis system. The relationship between surveyed factors and MP was evaluated using Spearman's rank correlation, Kruskal-Wallis test, generalized linear regression, and analysis of covariance. Results: Participants with F–F and V–F combined RR forms had the lowest MP, while those with U–U and U–I forms had the highest MP, regardless of RR height. Participants with low RR height had the lowest MP, and those with high RR height had the highest MP, regardless of RR form. The analysis of covariance revealed that mandibular RR height, combined RR forms, and total occlusal contact area significantly affected the MP. Conclusions: Our findings confirmed that the mandibular RR height, RR form combinations, and occlusal contact influence the MP of CD wearers. Clinical Implications: The MP of CD wearers varied, depending on the height and form of the RR, as well as the occlusal contact area of the CDs. The results of this manuscript show that the morphology of the denture bearing area and the occlusion of the CDs are essential factors in predicting the treatment outcome of CD wearers. This allows the clinician to fabricate a complete denture with the denture basal surfaces adjusted and occlusion provided according to the patient. CD patients can be educated on how to chew to improve MP based on their own RR morphology.
AB - Statement of the problem: Morphology of the residual ridge (RR) is expected to influence the masticatory performance (MP) of complete denture (CD) patients, but considerable details of this relationship are unknown. Purpose: We aimed to investigate the association between the objective MP and RR morphology of CD wearers and other contributory factors affecting their MP. Materials and methods: Sixty-five patients with well-fitting upper and lower CDs with no complaints of pain were enrolled. The objective MP was measured using test gummy jelly and a fully automated measuring device. The RR form was divided into U-type, V-type, I-intermediate, and F-Flat, then combinations of upper and lower RR forms (combined RR) were classified. The height was measured using CD's denture basal surface replicas, while occlusal contact of CDs was assessed using a tooth contact analysis system. The relationship between surveyed factors and MP was evaluated using Spearman's rank correlation, Kruskal-Wallis test, generalized linear regression, and analysis of covariance. Results: Participants with F–F and V–F combined RR forms had the lowest MP, while those with U–U and U–I forms had the highest MP, regardless of RR height. Participants with low RR height had the lowest MP, and those with high RR height had the highest MP, regardless of RR form. The analysis of covariance revealed that mandibular RR height, combined RR forms, and total occlusal contact area significantly affected the MP. Conclusions: Our findings confirmed that the mandibular RR height, RR form combinations, and occlusal contact influence the MP of CD wearers. Clinical Implications: The MP of CD wearers varied, depending on the height and form of the RR, as well as the occlusal contact area of the CDs. The results of this manuscript show that the morphology of the denture bearing area and the occlusion of the CDs are essential factors in predicting the treatment outcome of CD wearers. This allows the clinician to fabricate a complete denture with the denture basal surfaces adjusted and occlusion provided according to the patient. CD patients can be educated on how to chew to improve MP based on their own RR morphology.
KW - Complete dentures
KW - Gummy jelly
KW - Mastication
KW - Masticatory performance
KW - Residual ridge
UR - http://www.scopus.com/inward/record.url?scp=85160235566&partnerID=8YFLogxK
U2 - 10.1016/j.heliyon.2023.e16238
DO - 10.1016/j.heliyon.2023.e16238
M3 - Article
AN - SCOPUS:85160235566
SN - 2405-8440
VL - 9
JO - Heliyon
JF - Heliyon
IS - 5
M1 - e16238
ER -