The goal of this clinical trial is to compare implant stability, and crestal bone loss, when using minimal invasive ridge splitting versus convenient open flap technique. The main question is Does Minimal Invasive Implant ridge splitting ("transmucosal" without flap) influence the implant stability and crystal bone loss, when compared with the conventional open flap techniques? Researchers will compare Group A: Minimal Invasive Implant ridge splitting and Group B: Triangular flap technique is used to see if there is significant difference between the two groups when measuring implant stability, and crestal bone density.

Diagnostic stage:

Explanation of the operative procedure and obtaining the participants consent. Comprehensive clinical examination and understanding of participants chief complains and needs will be carried out.

CBCT acquisition:

Cone Beam Computed Tomography (CBCT) scans for the participants will be Taken preoperatively to determine the following:

1. Bone density (D1 & D4 for exclusion, while D2 & D3 shall be included)
2. To confirm the ridge mapping indicating alveolar ridge class IV. (Where height is adequate > 10mm, while width is "3-4 mm").

Planning the surgical procedure:

All planned surgical procedure will be carried out by main candidate under supervision.

Implant are planned to be placed (2 implants are placed in each segment "30-40 mm")

Surgical procedure:

Scrubbing and draping of the participants will be carried out in a standard fashion.

Local anesthesia (lidocaine 2%o,1/100000 adrenaline) Group A: Minimal Invasive Implant ridge splitting. A horizontal incision is made using fine end bur with high-speed hand piece deep from the edge of the ridge, passing down the cortical plate to the depth of the spongy bone, without mucoperiosteal elevation.

Using specially designed implant like bone expanders (Champions implants GmbH) to widen ridge with sequential application (which are 2.4, 2.8, 3.0, 3.3,3.8,4.3, and 5.3 mm in Diameter).

With each step the investigators shall carefully check the bone integrity and depth using calibrated probe.

By reaching the desired depth and width (till size 3.3 condensers and place 3.5 x 8 mm implants as a standard, using torque gage adjusted at 30-40 Newton's, that's to avoid pressure that might lead to initial resorption.

Closure of the incision line using interrupted suturing.

Group B: Triangular flap technique is used. With the horizontal component on the ridge and the vertical component posteriorly to avoid injury to the mental nerve, allowed by mucoperiosteal elevation to expose the target area.

2 vertical cuts on both ends to facilitate the ridge expansion, without the risk of crack or fracture of the buccal segment using conventional chisels till reaching the desired width that would accommodate the same implant diameter as for group A.

Inclusion criteria:

1. Patients with atrophic posterior mandibular ridge with edentulous area 30-40 mm, minimum width 3-4 mm, and adequate height indicated for implant placement >9 mm.
2. Patient with Bone density D2 and D3.
3. Good general systemic condition.
4. Committed patient to attend follow up appointment.

Exclusion criteria:

1. Patients with systemic diseases that may affect the healing process of hard or soft tissues (e.g., uncontrolled diabetes mellitus).
2. Patient on medication that could hinder the normal healing process (e.g., steroids, immunosuppressant)
3. Patients with intra-bony lesions or infections.
4. Patient with bad habits (e.g. alcohol or Substance abuse).
5. Patient who received head and neck radiotherapy or chemotherapy in the last 10 years.