Alteration of Oral and Perioral Soft Tissue in Mice following Incisor Tooth Extraction.

Takahiro Takagi,Chiemi Kanehira,Masateru Katayama,Aki Sugano,Masaki Sato,Kei Kitamura,Katsuhiko Sakai,Masahito Yamamoto,Shinichi Abe

doi:10.3390/ijms23062987

Takahiro Takagi, Chiemi Kanehira + Show 7 more

Open Access

https://doi.org/10.3390/ijms23062987

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Abstract

Oral and perioral soft tissues cooperate with other oral and pharyngeal organs to facilitate mastication and swallowing. It is essential for these tissues to maintain their morphology for efficient function. Recently, it was reported that the morphology of oral and perioral soft tissue can be altered by aging or orthodontic treatment. However, it remains unclear whether tooth loss can alter these tissues’ morphology. This study examined whether tooth loss could alter lip morphology. First, an analysis of human anatomy suggested that tooth loss altered lip morphology. Next, a murine model of tooth loss was established by extracting an incisor; micro-computed tomography revealed that a new bone replaced the extraction socket. Body weight was significantly lower in the tooth loss (UH) group than in the non-extraction control (NH) group. The upper lip showed a greater degree of morphological variation in the UH group. Proteomic analysis and immunohistochemical staining of the upper lip illustrated that S100A8/9 expression was higher in the UH group, suggesting that tooth loss induced lip inflammation. Finally, soft-diet feeding improved lip deformity associated with tooth loss, but not inflammation. Therefore, soft-diet feeding is essential for preventing lip morphological changes after tooth loss.

Highlights

Tooth loss significantly impacts aesthetics, food selection, diet, and nutritional intake [1]; it burdens people with severe mental illnesses [2], and increases the risks of cardiovascular disease [3–5], head and neck cancer [6], and esophageal cancer [7]
Magnetic Resonance Imaging (MRI) revealed that the lip bent toward the oral cavity side in group B compared with the findings in group A (Figure 1Aa–d)
inferior tip (In) the cadaver analysis, the lip bent toward the oral cavity side in group B compared with the findings in group A (Figure 1Ba–c)

Summary

Introduction

Tooth loss significantly impacts aesthetics, food selection, diet, and nutritional intake [1]; it burdens people with severe mental illnesses [2], and increases the risks of cardiovascular disease [3–5], head and neck cancer [6], and esophageal cancer [7]. Alveolar bone resorption occurs following tooth extraction, as a direct result of tooth loss [12]. It remains unclear whether tooth loss can alter the morphology of oral and perioral soft tissue. The lips, which are oral and perioral soft tissue, are composed of surface epidermis, a muscle layer, connective tissue, and oral mucosal epithelium [13]. Lip morphology is altered in patients undergoing orthodontic treatment. Changes in the lip contour occur following maxillary incisor retraction [14]. The vertical position of the lip changes significantly following anterior tooth retraction [15].

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