28 Results of individual studies Detailed outcome scores of each study are presented in Table 1. HR-QoL masticatory ability scores clustered by time are presented in Figure 2. Vakil et al. did not report any specific data to compare with other studies included in the present review.23 Agarwal et al. showed that the ability to chew solid food at baseline reduced to only semisolids and liquids post-treatment.24 Li et al. followed 47 hemiglossectomy patients and reported that only 7 patients complained about a negative effect on chewing ability.39 Rogers et al. stated that chewing scores were maintained over time.27 An 8-year longitudinal study by Yan et al. showed the worst QoL-scores for mastication 3 months post-treatment.41 The scores improved at the 1-year assessment and remained the same at the 8-year assessment. Nonetheless, overall, the problems with chewing significantly worsened between time of diagnosis and 8 years after treatment. Rogers et al. showed an improvement from 2 years to 10 years post treatment.31 Bekiroglu et al. reported a mean decline in chewing of 25 points after 1 year for patients treated with a combination of surgery and RT, and a mean decline of 7 points for those treated with surgery without RT.25 The percentage of patients considering chewing as one of the 3 most important domains of the UW-QoL differed between 33.3% (2nd rank)36 and 94.1% (1st rank).38 Other studies only reported the rank of the chewing domain: 1st rank,35,40,46 2nd rank,45 and 3rd rank.45 Soares et al. used an alternative way to present outcomes. At 41.5 months, patients scored as follows: cannot chew anything (n=26), chews light food (n=20) and chews light food and solids (n=1). There were no significant associations between chewing scores and demographic or clinical variables.26 Ochoa et al. reported patients scores as follows: I cannot even chew soft solids (n=0), I can eat soft solids but cannot chew some foods (n=2), I can chew as well as ever (n=37). Chewing was one of the worst scoring domains in this study.49 Vakil et al. also presented their findings in a slightly different manner. A score from 1 to 3 was used, where 1 indicated no change in chewing function and 3 indicated that patients could not chew soft food. In this study, the most frequently occurring value was 2 with a standard deviation of 0.7.23