# A Novel Color-Based Segmentation Method for the Objective Measurement of Human
## 4 Discussion  
In the present study, a novel method for the assessment of MP was proposed and described. MP was evaluated using a sample constituted by fully dentate young adults who chewed a two-colored chewing gum for different numbers of chewing cycles. Previous studies stated that a reduction in MP is more pronounced in patients with less than 20 teeth. In this report, 50 fully dentate participants were enrolled to determine the validity of the proposed method as they were considered ideal chewers [23; 24]. They were fully dentate, in angle class I, with a DMFT \(<4\), and with no TMJ disorders. The choice \begin{table}
\begin{tabular}{c c} \hline
**Sociodemographic Data** & **Value** \\ \hline Sex & \\ Male & 25 \\ Female & 25 \\ Age & \(24.3\pm 2.7\) \\ Clinical Data & \\ Natural teeth & \(28\pm 0.0\) \\ Oclusal units & \(14\pm 0.0\) \\ Filled teeth & \(1.2\pm 1.0\) \\ \hline \end{tabular}
\end{table} 
Table 1: Sociodemographic and clinical variables of sample size (\(n=50\)). Data values are expressed as the number of participants for sex and mean and standard deviation (SD) for all other values. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Chewing Cycles** & **5** & **10** & **20** & **30** & **50** \\ \hline MP & \(0.228\pm 0.122\) & \(0.319\pm 0.139\) & \(0.443\pm 0.138\) & \(0.466\pm 0.111\) & \(0.830\pm 0.247\) \\ Sex & & & & & \\ Male & \(0.259\pm 0.110\) & \(0.352\pm 0.129\) & \(0.470\pm 0.157\) & \(0.466\pm 0.147\) & \(0.880\pm 0.237\) \\ Female & \(0.197\pm 0.128\) & \(0.286\pm 0.145\) & \(0.416\pm 0.112\) & \(0.466\pm 0.059\) & \(0.780\pm 0.252\) \\ \hline \end{tabular}
\end{table} 
Table 2: Masticatory performance (MP) values according to the number of chewing cycles. The results are expressed as the mean and standard deviation (SD). of a sample with these characteristics was considered crucial for the validation of the proposed software [10; 12; 16; 18; 25; 26]. A recent systematic review stated that no established method for the clinical assessment of MP with a high level of evidence is available. Furthermore, all the proposed assessment methods reported in the literature need lab-intensive equipment, such as digital image software or sieves [25]. In 2018, [PERSON] et al. tested the accuracy of a custom-built smartphone application, trying to overcome the need for specific and expensive instruments. Unfortunately, further development of that proposed application is not likely to happen [27]. In the present study, MP was evaluated using the k-means clustering technique. For each chewing gum wafer, mixed areas were evaluated. This clustering system using color information provided a high discriminative power for regions present in each image, reducing the errors due to manual segmentation. In particular, this method expressed MP as the percentage of mixed areas, where an MP of 1 indicates an optimal MP and an MP of 0 indicates the total absence of it. Using the k-means clustering method, the MP was evaluated for each bolus by estimating the mixed and unmixed areas. This clustering system is able to provide high discriminative power for the regions present in each image using color information. Moreover, a reduction of the errors due to manual segmentation could be achieved. A significant increase in color mixing was observed in accordance with the different numbers of chewing cycles, as demonstrated in previous studies [13; 28]. MPs corresponding to 5, 10, 20, 30, and 50 chewing strokes were compared. According to previous studies [10; 28; 29; 30; 31], a significant increase in color mixing depends on the number of chewing cycles, where 20 masticatory cycles were enough to determine the different MPs of subjects with different dental statuses. The variability between the MPs for different numbers of masticatory cycles, as shown in Figure 4, was in accordance with this datum, showing that 20 chewing strokes could be considered the right number of strokes that could show a difference in MPs.