Aim: To study the condition of oral tissues in children with congenital complete cleft lip, alveolar process, hard and soft palate. Materials and Methods: From the examined 470 children National Specialized Children’s Hospital “OKHMATDYT” (Kyiv, Ukraine) with congenital cleft lip and palate was analyzed: 302 patients aged 8-18 years were subject to in-depth analysis for clinical and radiological – 192 with unilateral and 110 with bilateral complete cleft lip, alveolar process, hard and soft palate. Results: The average value of primary adention in patients with unilateral and bilateral complete combined cleft is 69.53%, but in females this indicator is higher and in unilateral cleft 92.18% for female against 53.17% for male. In females with unilateral cleft retention – 40.62% and overcomplete – 10,93%. The same high indicators in bilateral cleft: retention – 36.58% and overcomplete – 12.19%. Retention and overcomplete have higher values for men – 44.93% and 23.19%, respectively. Chewing efficiency in females with bilateral cleft as a result of primary dentition is below 80%. Affected by caries – 90.73% in both groups. Inflammatory processes in the periodontal tissues are revealed (80,75%): chronic catarrhal gingivitis, chronic hypertrophic gingivitis, chronic generalized periodontitis. Manifestations of atopic and angular cheilitis in 39.09% and 23.63% with bilateral cleft lip and palate, glossitis in 29.09%. Conclusions: Patients with congenital complete cleft lip, alveolar process, hard and soft palate have high rates of adentia, retention, overcomplete dentition and a wide range of diseases of the oral cavity, which negatively affects surgical and orthodontic rehabilitation.