Abstract Background Several methods have been described for treating deep Cairo Class RT1 recessions. Most involve relieving incisions, which cause scar tissue formation or use a tunneled approach. This report introduces a modified technique for treating a single deep recession beyond the mucogingival margin. The approach uses a laterally closed coronally advanced flap (LCAF) without relieving incisions, combined with a subepithelial connective tissue graft and enamel matrix derivative. Methods A 28‐year‐old woman was referred to our periodontal practice for the treatment of a progressive deep Cairo Class I recession with hypersensitivity and limited access to hygiene measures. The root coverage procedure was performed using a modified LCAF, combined with a connective tissue graft from the palate and enamel matrix derivative. The case was followed for 6 months. Results The healing process was uneventful. Six months after surgery, the root surfaces remained completely covered. Hypersensitivity resolved entirely, and there was only a slight formation of visible scar tissue. Conclusions This modified technique of an LCAF is a feasible and effective method for treating single deep RT1 recessions. By avoiding visible relieving incisions, scar tissue formation is minimized. The preparation of an LCAF allows for adequate coronal advancement. Key points As far as our knowledge, this is the first description of a laterally closed coronally advanced flap (LCAF) combining the advantage of a minimalized scarring root coverage with a simplified coronally advancement for recessions exceeding the mucogingival junction. This modified technique combines the advantages of a lateral closing with a CAF for covering deep class RT1 recessions. Meticulous handling of the delicate pedicles combined with a coronal advancement of at least 2 mm beyond the cemento‐enamel junction is the key factor for the successful adaption of this technique. Plain language summary Deep gum recessions originating from traumatic hygiene measures can cause hypersensitivity and limit patients´ access to oral hygiene. Especially in deep recessions, the common surgical techniques have shortcomings due to a post‐surgical lack of keratinized gingiva or visible scar tissue formation. This case study shows the treatment of a 28‐year‐old woman´s deep recession on a mandibular front tooth introducing a modified surgical technique for covering deep gum recessions exceeding the area of the keratinized gingiva (so‐called deep Cairo RT1 recessions). This new technique uses a “laterally closed coronally advanced flap” (LCAF), which combines a curtain‐similar lateral closing of the flap pedicles with a coronal advancement to cover the recession without making cuts that can lead to scars. It is combined with a tissue graft from the patient's palate and a special protein to regenerate the periodontium. Six months after surgery, complete root coverage was achieved without remaining hypersensitivity and with restored access for oral hygiene measures. Minimal visible scar tissue formed. This case study demonstrates that the LCAF is a feasible technique for covering single deep gum recessions exceeding the keratinized area of the gingiva.