## 2 Materials and Methods  
The reconstruction method is presented based on a case description of a 21-year-old, generally healthy patient who was referred to a dental clinic due to pathological mobility of his front teeth in the mandible. The patient had started orthodontic treatment with fixed appliances three months earlier. The patient has never undergone any surgical or periodontal treatment in a given area of the mandible. He also denied facial injuries. A clinical examination revealed an inadequate amount of keratinized gingiva, Miller grade II gingival recession in the area of tooth 42 (right lateral incisor in the mandible), a thin biotype of the gingiva with the correct vestibule height, as well as marked alveolar concaves and convexities [Figure 1]. Probing depth (PD) was 1-2 mm around lower incisors and canines. Bleeding on probing (BoP) was found in incisors. Attention was also paid to insufficient oral hygiene and plaque and calculus deposits. The patient underwent scaling and root planning. It was also recommended to perform cone-beam computed tomography (CBCT) of the anterior mandible. CBCT scans were captured using Pax Flex3D Vatech Computer Tomography X-ray System (Vatech, Hwaseong-si, Gyeonggi-do, Korea) with FOV 80 mm width and 50 mm height. Images were analyzed using EzDent-i software (Vatech, Hwaseong-si, Gyeonggi-do, Korea). A radiological examination revealed a significant bone deficiency in this area, with clearly marked concavities in the alveolar part of the mandible. Advanced bone dehiscences from the vestibular side, with almost complete exposure of the anterior tooth roots, were also seen [Figures 2-4]. Figure 1: Clinical picture before treatment showing the inadequate amount of keratinized gingiva, Miller grade II gingival recession in the area of tooth 42, a thin biotype of the gingiva with the correct vesibule height as well as including calculus, gingival recessions, and alveolar concavies and concavities. Figure 2: CBCT image before the treatment showing advanced bone defects—three-dimensional reconstruction. The morphology of this region could be classified as C according to the alveolar bone dehiscence classification proposed by [PERSON] et al. (2015). This means that the dehiscence is bilateral. In turn, according to the modification of this classification presented by [PERSON] et al., which is more detailed, such a defect could be classified as BDIEII dehiscence from the vestibular side, which reaches an apical foramen, and bone loss from the lingual side is at the level of 1/2 of the root's length ([PERSON] et al., 2016). Due to the inadequate dimensions and volume of soft tissues, as well as the consistent lack of the possibility of adequate bone reconstruction without excessive tension, it was decided to start with gingival augmentation--connective tissue graft (CTG). Tissue grafts are an indispensable stage in the reconstruction of the mucoginguival complex. Under local anesthesia with a 4% solution of articaine with epinephrine 1:100,000 (Ubistesin forte, 3M\({}^{\text{TM}}\) eSPe\({}^{\text{TM}}\), Wroclaw, Poland) the receiving bed in area 32-42 was prepared. A CTG was obtained from the palate and was then sutured into the recipient site. Excessive activity of the mental muscle, which causes the pull of soft tissues, was eliminated by intramuscular injection of botulinum toxin (0.6 mL in the horizontal line; usually, about 24 IU is required (BOTOX\({}^{\text{\textregistered}}\) Cosmetic, Allergan, Dublin, Ireland) ([PERSON] et al., 2016; [PERSON] et al., 2016). In the clinical follow-up examination, which was conducted after less than three months, the adequate width and thickness of the soft tissues, as well as the complete coverage of the recession in the area of tooth 42 were recorded. It was therefore decided to start bone reconstruction surgery. Figure 3: CBCT image before the treatment showing an almost complete loss of the buccal bone— sagittal section.