AIM: In this case report, the treatment results of slow maxillary expansion in a male patient with skeletal class I malocclusion and growth modification are presented.
CASE REPORT: In the extraoral examination of the male patient with a chronological age of 8 years and 8 months, it was observed that his facial features were proportional and symmetrical, there were no joint findings, and his profile was convex. In the intraoral examination, it was determined that the growth development period was PP2=, Angle Class III subdivision relationship, 1 mm in overjet number 11, -1 mm in number 21, overbite 1 mm, growth direction optimum. In the model analysis, 4 mm space deficiency was calculated in the maxillary dental arch, and no space deficiency was observed in the mandibular dental arch. In the cephalometric analysis, a skeletal Class 1 relationship was detected. In addition, crossbite was observed in tooth 21 of the upper incisor. In this case report, a three-way movable slow expansion appliance was adjusted and expansion was started with 2 rounds per week. As a result of the analysis of the orthodontic material collected at the end of the treatment, skeletal class 1, Angle Class I, overjet 2mm, overbite 2 mm, the space deficiency in the mandible and maxilla has been resolved, the normoposition of the upper and lower incisors and normoversiyon was observed. CONCLUSION: Slow maxillary expansion was applied to the patient. The crossbite of tooth number 21 was corrected. After 9 months of treatment, the retention phase was started and the patient was followed up until the permanent dentition period, provided that he was seen every 3 months. The functional treatment period of our patient lasted for 9 months.