I. Introduction

II. Methods
1. Focused questions
2. Search strategy
4. Exclusion criteria
5. Study selection and data synthesis
6. Statistical analysis

III. Results
Table 1
Study |
Follow-up less than 6 months |
Lack of data on preoperative and/or postoperative measurements |
Lack of data on etiology |
Conflicting data |
Study design |
No surgical intervention |
---|---|---|---|---|---|---|
Ramesh et al.20 (2019) | * | |||||
Foudah21 (2019) | * | |||||
K et al.22 (2018) | * | * | ||||
Faus-Matoses et al.23 (2018) | * | * | ||||
Sharma et al.24 (2017) | * | * | ||||
Sánchez et al.25 (2017) | * | |||||
Littuma et al.26 (2017) | * | |||||
Khan et al.27 (2017) | * | |||||
Gibson and Tatakis28 (2017) | * | |||||
Farista et al.29 (2017) | * | |||||
Mahn30 (2016) | * | |||||
Aly and Hammouda31 (2016) | * | |||||
Rao et al.32 (2015) | * | |||||
Muthukumar et al.33 (2015) | * | * | ||||
Bhola et al.34 (2015) | * | |||||
Storrer et al.35 (2014) | * | * | ||||
Grover et al.36 (2014) | * | |||||
Gaddale et al.37 (2014) | * | |||||
Sheth et al.38 (2013) | * | |||||
Humayun et al.39 (2010) | * | |||||
Gupta et al.40 (2010) | * | * | ||||
Simon et al.15 (2007) | * | |||||
Rosenblatt and Simon41 (2006) | * | * | ||||
Ambrosio et al.42 (2018) | * | |||||
Assenza et al.43 (2011) | * | |||||
Ergezen et al.44 (2017) | * | |||||
Mangano and Mangano45 (2013) | * | |||||
Polo46 (2011) | * |
Table 2
Study | Study design | No. of patients | Sex | Age (yr) | Etiology | Surgical technique | Additional intervention | Follow-up duration (mo) | Preoperative display (mm) | Postoperative display (mm) | Complications |
---|---|---|---|---|---|---|---|---|---|---|---|
Ganesh et al.47 (2019) | Case report | 1 | F | 25 |
1. APE 2. HUL |
Type of instrument: diode laser (940 nm), 400 µm laser tip/continuous mode at 0.8 W Lower incision: MGJ Upper incision: 10 mm Type of incision: partial thickness MD extension: maxillary premolar Suturing: resorbable (muscle containment)/4-0 silk interrupted Removed after 14 days |
1. Muscle containment 2. Crown lengthening: laser gingivectomy |
12 | 7 | 3 |
1. Mild pain and tension 1st week 2. Minor scar |
Torabi et al.48 (2018) | Case report | 3 |
2 F 1 M |
41-54 |
1. VME 2. HUL 3. APE |
Type of instrument: blade Lower incision: MGJ Upper incision: labial vestibule Type of incision: partial thickness (periosteal fenestration) MD extension: maxillary 1st molar Suturing: 4-0 silk, 4-0 Vicryl/ suspensory triangular+extraoral stabilization tape |
N/A | 13-16 | 6.3±4.06 |
2 months: 0.96±0.73 6 months: 0.76±0.87 13-16 months: 0.72±0.96 |
N/A |
Tawfik et al.49 (2018) | RCT |
Group 1: 20 Group 2: 20 |
18 F 2 M |
N/A | Various etiologies |
Type of instrument: #15 blade Lower incision: MGJ Upper incision: 2× the display Type of incision: partial thickness MD extension: maxillary 1st molar Suturing: 5-0 polyglycolic sutures/continuous & interrupted Removed after 14 days |
Myotomy: Group 1 | 12 |
Group 1: 6.29±2.6 Group 2: 4.31±1.12 |
Group 1: 3 months: 3±1.53 6 months: 3.42±1.23 12 months: 3.57±1.62 Group 2: 3 months: 1.65±0.90 6 months: 2.21±1.0 12 months: 2.73±1.28 |
1. Pain 2. Swelling 3. Numbness |
Alammar and Heshmeh50 (2018) | Case series | 14 | N/A | 18-38 |
1. SUL 2. HUL |
Type of instrument: blade Lower incision: 1 mm coronal to MGJ Upper incision: 10-12 mm Type of incision: full thickness MD extension: maxillary 1st molar Suturing: 4-0 Vicryl (muscle), 3-0 silk (mucosa)/interrupted sutures Removed after 14 days |
1. Myotomy 2. Crown lengthening |
6 | 6.36±1.12 |
1 month: 0.91±1.22 3 months: 2.27±1.27 6 months: 2.45±1.13 |
1. Scar 2. Tension in the upper lip 3. Minimal discomfort 4. Ecchymosis 5. Edema 6. Flap dehiscence 7. Numbness |
Alammar et al.51 (2018) | PCT | 22 |
19 F 3 M |
18-38 |
1. SUL 2. HUL (lip mobility >8 mm) |
Type of instrument: blade Lower incision: 1 mm coronal to MGJ Upper incision: 10-12 mm Type of incision: partial thickness (Group 1)full thickness (Group 2) MD extension: maxillary 1st molar Suturing: 3-0 silk/interrupted (Group 1) 4-0 Vicryl (muscle), 3-0 silk (mucosa)/ interrupted (Group 2) Removed after 14 days |
1. Myotomy (Group 2) 2. Crown lengthening |
6 |
5.82±0.87 (Group 1) 6.36±1.12(Group 2) |
Group 1: 1 month: 2.18±0.75 3 months: 2.55±0.93 6 months: 3.27±0.79 Group 2: 1 month: 0.91±1.22 3 months: 2.27±1.27 6 months: 2.45±1.13 |
1. Scar 2. Tension in the upper lip 3. Minimal discomfort 4. Ecchymosis 5. Edema 6. Flap dehiscence 7. Numbness |
Storrer et al.52 (2017) | Case report | 1 | F | 23 | HUL |
Type of instrument: #15C blade Lower incision: MGJ Upper incision: N/A Type of incision: partial thickness MD extension: maxillary canines Suturing: 5-0 nylon/4-0 silk/interrupted external sutures removed after 10 days |
1. Muscle containment 2. Frenectomy 3. Crown lengthening |
24 | 8 |
2 mm midline 4 mm lateral incisors |
Tension |
Mantovani et al.53 (2016) | Case report | 1 | F | 23 |
1. HUL 2. APE |
Type of instrument: N/A Lower incision: 1 mm coronal to MGJ Upper incision: 10-12 mm Type of incision: partial thickness MD extension: maxillary 1st molars Suturing: 5-0 polygalactin/continuous interlocking sutures |
Crown lengthening: 2 mm after lip repositioning | 9 | 5 | 6 months: 0-1 | N/A |
Abdullah et al.54 (2014) | Case series | 12 |
10 F 2 M |
20-29 | N/A |
Type of instrument: blade Lower incision: 4-5 mm from gingival margin Upper incision: 8-10 mm Type of incision: full thickness MD extension: maxillary 2nd premolar Suturing: 3-0 Vicryl/interrupted Removed after 14 days |
1. Myotomy 2. Frenectomy |
12 | 5±0.95 |
1 month: 2.66±0.77 3 months: 3.08±1.16 6 months: 3.08±1.16 12 months:3.08±1.16 |
1. Feeling of tension 2. Mild pain 3. Ecchymosis 4. Edema 5. Complete relapse in 1 patient after 3 months |
Ozturan et al.55 (2014) | Case series | 10 | F | 22-34 | HUL |
Type of instrument: diode laser (940 nm, 4 W, continuous wave) Lower incision: MGJ Upper incision: 10-12 mm Type of incision: partial thickness Procedure was done in two stages left/right. MD extension: maxillary 1st molars Suturing: 5-0 monofilament/continuous interlocking |
N/A | 12 | 4.3±1.8 |
6 months: 1.1±1.0 12 months: 1.2±1.5 |
N/A |
Jananni et al.56 (2014) | Case report | 1 | F | 18 |
1. VME 2. HUL |
Type of instrument: blade #15 Lower incision: MGJ Upper incision: 2× the display Type of incision: partial thickness MD extension: maxillary 2nd premolars Suturing: 4-0 silk/continuous interlocking sutures/periodontal pack Removed after 14 days |
N/A | 18 | 6 | 4 | N/A |
Gabrić Pandurić et al.57 (2014) | Case report | 1 | F | 27 |
1. VME 2. HUL 3. APE |
Type of instrument: diode laser (975 μm, 4 W, CW) Lower incision: MGJ Upper incision: 1.5× display Type of incision: partial thickness MD extension: maxillary 1st molars Suturing: 3-0 silk/interrupted sutures Removed after 10 days |
1. Frenectomy 2. Crown lengthening: laser gingivectomy |
6 | 5.5-10 | 0-2 |
1. Tension 2. Slight pain 3. Numbness 1st week 4. Scar |
Dayakar et al.58 (2014) | Case report | 1 | F | 22 | N/A |
Type of instrument: blade Lower incision: MGJ Upper incision: 10-12 mm Type of incision: partial thickness MD extension: maxillary 1st molars Suturing: continuous interlocking Removed after 14 days |
N/A | 12 | 5-6 |
3 months: 3 6 months: 3 12 months: complete relapse |
1. Mild pain and tension 1st week 2. Scar |
Silva et al.59 (2013) | PCT | 13 |
11 F 2 M |
19-49 | HUL |
Type of instrument: N/A Lower incision: 1 mm coronal to MGJ Upper incision: 10-12 mm Type of incision: partial thickness MD extension: maxillary 1st molar Suturing: 4-0 polygalactin/continuous interlocking sutures |
N/A | 6 | 4-10 (5.8±2.1) |
3 months: 0-3 (1.4±1.0) 6 months: 0-5 (1.3±1.6) |
1. Tension 2. Scar |
Ribeiro-Júnior et al.60 (2013) | Case report | 2 | F | 20-22 |
1. HUL 2. APE(1 patient) |
Type of instrument: N/A Lower incision: 1 mm coronal to MGJ Upper incision: 10-12 mm Type of incision: partial thickness MD extension: maxillary 1st molars Suturing: 4-0 poligalactin/continuous interlocking sutures Removed after 14 days |
Crown lengthening: 1 patient | 6 |
7 6 |
1 |
1. Tension 1st week 2. Scar |
Jacobs and Jacobs61 (2013) | Case series | 7 | F | 21-59 | N/A |
Type of instrument: diode laser/#15 blade Lower incision: MGJ Upper incision: 2× display Type of incision: partial thickness MD extension: maxillary 1st molars Suturing: 3-0 chromic or silk/interrupted or continuous interlocking sutures |
N/A | 1-36 | 5.36±1.5 | 1.1±2.5 |
1. Scar 2. Pain, swelling and tension 1st week |
Ishida et al.8 (2010) | Case series | 14 | F | 15-35 | N/A |
Type of instrument: #15 blade Lower incision: N/A Upper incision: N/A Type of incision: N/A MD extension: N/A Suturing: 5-0 resorbable/interrupted |
1. Myotomy 2. Frenectomy |
6-18 | 5.22±1.48 | 6 months: 1.91±1.50 | N/A |
Table 3
Study | Aim | Inclusion | Data collection | Endpoint | Evaluation (bias) | Follow-up period | Loss to follow-up |
Sample size |
Total score |
---|---|---|---|---|---|---|---|---|---|
Ganesh et al.47 (2019) | 2 | 1 | 1 | 2 | 1 | 2 | 2 | 0 | 11 |
Torabi et al.48 (2018) | 1 | 2 | 1 | 2 | 2 | 2 | 2 | 1 | 13 |
Alammar and Heshmeh50 (2018) | 2 | 2 | 2 | 2 | 1 | 1 | 2 | 1 | 13 |
Storrer et al.52 (2017) | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 0 | 8 |
Mantovani et al.53 (2016) | 2 | 1 | 1 | 1 | 0 | 1 | 2 | 0 | 8 |
Abdullah et al.54 (2014) | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 15 |
Ozturan et al.55 (2014) | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 15 |
Jananni et al.56 (2014) | 0 | 1 | 1 | 1 | 1 | 2 | 2 | 0 | 8 |
Gabrić Pandurić et al.57 (2014) | 2 | 1 | 2 | 2 | 2 | 2 | 2 | 0 | 13 |
Dayakar et al.58 (2014) | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 0 | 9 |
Silva et al.59 (2013) | 2 | 2 | 2 | 2 | 2 | 1 | 2 | 1 | 14 |
Ribeiro-Júnior et al.60 (2013) | 2 | 1 | 1 | 1 | 1 | 1 | 2 | 1 | 10 |
Jacobs and Jacobs61 (2013) | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 15 |
Ishida et al.8 (2010) | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 15 |
![]() | Fig. 2Forest plot of effect size for lip repositioning without myotomy/muscle containment after 6 months. (Std diff: standard difference, CI: confidence interval) |

IV. Discussion
