## 2 Materials and Methods
### Procedures  
All patients received therapy with rigid acrylic upper occlusal splint habit counseling and standardized behavioral recommendations. The occlusal splint was constructed after an occlusal registration and subsequent occlusal adjustment by the doctor. Patients were advised to wear the splint only at night while sleeping. All patients also received beneficial behavioral changes and were given a printed version of instructions on relaxation techniques, sleep hygiene, diet modification, thermotherapy, and pain management, as well as avoidance of dental clenching. In addition, the participants completed a questionnaire for the assessment of temporomandibular disorders, bruxism, and overall well-being before and after performing the treatment using a Michigan-type splint. The second phase of questionnaires were conducted after 1 month of treatment following the use of the Michigan-type splint based on prior research suggesting that early improvements in TMD symptoms can be detected within this timeframe [24]. Specifically, this questionnaire had 8 sections. (1) Jaw functional scale 8 (JFLS-8) [25]; (2) generalized anxiety disorder 7 (GAD-7) [26]; (3) oral health impact profile 14 (OHIP-14) [27]; (4) world health organization well-being index (WHO-5) [28]; (5) Pittsburgh sleep quality index (PSQI) [29]; (6) sleep bruxism [30]; (7) awake bruxism [30]; (8) joint sounds [5]; (9) temporomandibular joint pain [5]; (10) headache attributed to temporomandibular joint [31]; (11) headache attributed to bruxism [31]; and (12) jaw locking [5]. Then, the following sections contained categorical variables with specific questions to measure additional TMD, bruxism, and overall well-being, based on the patient's testimony and clinical examination. Specifically, the following variables were measured. Probable sleep bruxism, according to the Standardized Tool for the Assessment of Bruxism (STAB) [32] and positive responses (i.e., \"yes\" answer) to any of the followingbruism questions [30]: \"(a) Are you aware that you clench at night? ; (b) Has anyone told you that you clench or grind your teeth at night? ; (c) Do you wake up with a headache?\"  
Probable awake bruxism was diagnosed using the STAB (21) and based on a positive response to the following question: 'Are you aware of clenching or grinding your teeth during the day? Joint sounds [5], if affirming the following question: \"Have you had any noise(s) in the joint when moving or using the jaw?\"  
Temporomandibular joint pain [5]: The participant had to confirm that pain in the jaw, temple, ear, or front of the ear is always present or comes and goes. Also, the individuals had this disorder if answering yes to the following question: \"Did any of the following activities affect (i.e., did the pain improve or worsen) the pain in your jaw or temple on either side? Chewing hard or difficult-to-grind foods; Open the mouth or moving the jaw sideways or forward; Oral habits such as keeping teeth together, clenching, grinding, or chewing gum; Other jaw activities such as talking, kissing, or yawning\". Headache attributed to temporomandibular joint [31], if confirming headaches involving the temple area or any of the following activities changing the individual's headache (making it better or worse) located in the temples on either side: (a) Chewing hard or difficult to grind foods; (b) Open the mouth or move the jaw sideways or forward; (c) Oral habits such as keeping teeth together, clenching or grinding teeth or chewing gum; (d) Other jaw activities such as talking, kissing or yawning. Headache attributed to bruxism [31] if confirming headaches when waking up. Jaw locking [5] according to positive responses (i.e., \"yes\" answer) to the following questions: (a) \"Have you ever had your jaw locked, even for a moment, so that you could not fully open your mouth (even if it was for a moment and then unlocked)?\"; (b) Was that jaw locking severe enough that it limited your mouth opening and interfered with your ability to eat?