Declension table of ?prasannamukha

Neuter	Singular	Dual	Plural
Nominative	prasannamukham	prasannamukhe	prasannamukhāni
Vocative	prasannamukha	prasannamukhe	prasannamukhāni
Accusative	prasannamukham	prasannamukhe	prasannamukhāni
Instrumental	prasannamukhena	prasannamukhābhyām	prasannamukhaiḥ
Dative	prasannamukhāya	prasannamukhābhyām	prasannamukhebhyaḥ
Ablative	prasannamukhāt	prasannamukhābhyām	prasannamukhebhyaḥ
Genitive	prasannamukhasya	prasannamukhayoḥ	prasannamukhānām
Locative	prasannamukhe	prasannamukhayoḥ	prasannamukheṣu

Compound prasannamukha -

Adverb -prasannamukham -prasannamukhāt