OCR: ORAL HEALTH CENTRE OF WESTERN AUSTRALIA THE UNIVERSITY OF WESTERN AUSTRALIA  Oral Health Centre of Western Australia The University of Western Australia Institutional logo for The University of Western Australia and Oral Health Centre of Western Australia. Includes the university crest (blue shield with a swan) and the organization name alongside a stylized dragonfly graphic. # Occlusion **LEARNING OUTCOMES** * Importance of occlusal analysis for prosthetic treatment (indications) * Discuss clinical parameters of occlusion: TMJ, muscles of mastication, dental occlusion * Know how to assess TMJ, masticatory muscles, parafunctional habits, fremitus * Differentiate Confirmative and Reorganized approaches of prosthetic treatment. #### Learning Outcomes - Importance of occlusal analysis for prosthetic treatment (indications) - Discuss clinical parameters of occlusion: TMJ, muscles of mastication, dental occlusion - Know how to assess TMJ, masticatory muscles, parafunctional habits, fremitus - Differentiate Confirmative and Reorganized approaches of prosthetic treatment. Why is Occlusion Important? **occlusion** \a-klō′shən\ *n* (1645): 1. the act or process of closure or of being closed or shut off; 2. the static relationship between the incising or masticating surfaces of the maxillary or mandibular teeth or tooth analogues; **comp**, **ARTICULATION**, **CENTRIC OCCLUSION**, **COMPONENTS OF OCCLUSION**, **ECCENTRIC OCCLUSION**, **LINE OF OCCLUSION**, **LINEAR OCCLUSION**, **MONOPLANE OCCLUSION**, **PATHOGENIC OCCLUSION**, **SPHERICAL FORM OF OCCLUSION** **FROM**: Glossary of Prosthodontic Terms **SO MANY TEXTBOOKS!**  #### Definition of Occlusion **occlusion** \a-klō′shən\ *n* (1645): 1. The act or process of closure or of being closed or shut off. 2. The static relationship between the incising or masticating surfaces of the maxillary or mandibular teeth or tooth analogues. **Related Terms:** Articulation, Centric Occlusion, Components of Occlusion, Eccentric Occlusion, Line of Occlusion, Linear Occlusion, Monoplane Occlusion, Pathogenic Occlusion, Spherical Form of Occlusion. *Source: Glossary of Prosthodontic Terms* A collection of textbook covers related to dental occlusion and prosthodontics. Includes titles such as 'Functional Occlusion: From TMJ to Smile Design', 'Occlusion Made Easy', 'Dental Occlusion', 'Textbook of Dental Anatomy Physiology & Occlusion', 'Fundamentals of Occlusion', and others. These books visually represent the breadth of literature on the topic mentioned in the slide text. Masticatory system: made up of teeth, periodontium, articulatory system. These are all interconnected, but for the purpose of this lecture, we are mostly focusing on the articulatory system and the teeth.  #### The Masticatory System The masticatory system is composed of the teeth, periodontium, and the articulatory system. These components are interconnected; however, the primary focus of this discussion is the articulatory system and the teeth. Hierarchical diagram of the masticatory system showing components: Enamel, Dentine, Pulp (top), Teeth (middle-left), Periodontium (middle-left), Articulatory system (middle-right). Below are Gingivae, Bone, Periodontal membrane, Muscles, Occlusion, TMJ. Red circles highlight 'Teeth', 'Periodontium', and 'Articulatory system'. Caption reads: Masticatory system as depicted in Textbook of dental anatomy. **Occlusion** Indications for Occlusal Analysis - Prosthodontic treatment - TMJ/muscles assessment - Periodontal assessment - Mobility assessment - Functional discomfort - Mechanically failed restorative treatment - Bruxism diagnosis - Orthodontic treatment **Image Analysis:** Diagram illustrating occlusal contact and its related components: Tempomandibular Joint (TMJ), Muscles, Teeth, and Periodontium.  #### Indications for Occlusal Analysis - Prosthodontic treatment - TMJ/muscles assessment - Periodontal assessment - Mobility assessment - Functional discomfort - Mechanically failed restorative treatment - Bruxism diagnosis - Orthodontic treatment **System Components:** - Temporomandibular Joint (TMJ) - Muscles - Teeth - Periodontium Anatomical diagram illustrating the relationship between occlusal contact and surrounding structures. The image features a silhouette of a human head profile in yellow with internal anatomical components highlighted: the Temporo-Mandibular Joint (TMJ) is marked in red, muscles in orange, teeth in blue, and periodontium in green. A circular arrow labeled 'Occlusal contact' connects these elements to demonstrate their functional interplay. # Occlusion Indications for Occlusal Analysis Isolated teeth can not be treated separately Systematic and organized treatment planning is necessary #### Treatment Planning Principles - Isolated teeth cannot be treated separately. - Systematic and organized treatment planning is necessary. Occlusion Indications for Occlusal Analysis Obtaining good record of patient’s occlusion - Baseline record - Monitor occlusal changes - Monitor disease development - Assessment of treatment implications #### Importance of Occlusal Records Obtaining a good record of the patient’s occlusion is essential for: - Establishing a baseline record - Monitoring occlusal changes - Monitoring disease development - Assessment of treatment implications Occlusion **THE UNIVERSITY OF** **WESTERN AUSTRALIA Oral Health Centre Western Australia** Clinical Examination Parameters ■ Examination - TMJ - Masticatory muscles - Dental occlusion ■ Performed in conjunction with routine dental examination ■ Extra-oral assessment: - Masticatory muscles (masseter, temporalis, medial pterygoid, cervical muscles, suprahyoid muscles) - TMJ ■ Intra-oral assessment: - Masticatory muscles (lateral pterygoid, medial pterygoid) - Dental occlusion #### Examination Overview Clinical examination of occlusion is performed in conjunction with routine dental examination and includes: - TMJ - Masticatory muscles - Dental occlusion #### Assessment Categories **Extra-oral assessment:** - Masticatory muscles (masseter, temporalis, medial pterygoid, cervical muscles, suprahyoid muscles) - TMJ **Intra-oral assessment:** - Masticatory muscles (lateral pterygoid, medial pterygoid) - Dental occlusion Occlusion **THE UNIVERSITY OF** **WESTERN** **AUSTRALIA** **Oral Health Centre** **of Western Australia** TMJ Examination ► Determine if there is masticatory disorder • Pain (chronic, acute) • Sound (clicking, crepitus) • Limited movement (locking, trismus) • Midline deviation and Midline deflection <img>Illustration of hand measuring Average opening <img> <img>TMJ arthroscopic images showing joint surface <img>   #### Determining Masticatory Disorders Examination aims to identify: - **Pain:** Chronic or acute - **Sound:** Clicking or crepitus - **Limited movement:** Locking or trismus - **Midline deviation and Midline deflection** *Note: Average opening is measured as part of the functional assessment.* Clinical photograph of an arthroscopic view inside the temporomandibular joint (TMJ). The image shows the internal joint surface and anatomical structures relevant to TMJ examination. Second clinical photograph of an arthroscopic view inside the TMJ, showing the joint surface from a different angle or stage of movement compared to the first image. Occlusion **Midline deviation** **Midline deflection** **TMJ Examination** * Determine if there is masticatory disorder * **Pain** (chronic, acute) * **Sound** (clicking, crepitus) * **Limited movement** (locking, trismus) * **Midline deviation and Midline deflection**   #### Clinical Indicators of Disorder - **Pain** (chronic, acute) - **Sound** (clicking, crepitus) - **Limited movement** (locking, trismus) - **Midline deviation and Midline deflection** Clinical photo showing 'Midline deviation' during TMJ examination. The image displays an open mouth with a white curved arrow indicating the tongue's path deviating to one side from the center. Clinical photo showing 'Midline deflection' during TMJ examination. The image displays an open mouth with a white curved arrow pointing diagonally across the tongue, illustrating lateral displacement of the jaw movement. # Occlusion ## **TMJ Examination** ► Occlusion alteration was commonly applied to treat TMD and facial arthromyalgia - Not supported by evidence ► Any TMD-related occlusion treatment should be conservative and reversible (e.g. occlusal splint and removable prosthesis) ► TMD should be stabilized prior to extensive prosthodontic treatment ► Patient should be informed that prosthodontic treatment is not aimed to restore TMJ health De Boever et al; 2000 ![University of Western Australia and Oral Health Centre of Western Australia logos] #### Evidence-Based TMD Management - Occlusion alteration was commonly applied to treat TMD and facial arthromyalgia, but this is not supported by evidence. - Any TMD-related occlusion treatment should be conservative and reversible (e.g., occlusal splint and removable prosthesis). - TMD should be stabilized prior to extensive prosthodontic treatment. - Patients should be informed that prosthodontic treatment is not aimed at restoring TMJ health. # **Occlusion** The University of Western Australia | Oral Health Centre of Western Australia ### TMJ Examination ► Palpating TMJ capsules ► Posterior palpation - Index fingers in the ears as patient open and closes. ► Lateral palpation ► **Evaluate** - Pain - Joint sound - Disc movement   #### Palpation Techniques - **TMJ Capsules:** Palpating the joint area. - **Posterior Palpation:** Index fingers in the ears as the patient opens and closes. - **Lateral Palpation:** External assessment of the joint. **Evaluation Criteria:** - Pain - Joint sound - Disc movement Clinical photo demonstrating posterior palpation of the TMJ. A patient is shown with their mouth open and index fingers inserted into both ears to palpate the joint capsules during movement. Clinical photo demonstrating lateral palpation of the TMJ. A gloved hand is shown pressing on the temporomandibular joint area from the side while the patient's ear is visible in the background. # Occlusion ## TMJ Examination - **Mandibular movement evaluation** - **Movement smoothness** - **Mandibular translation** ### Midline deflection - **Continuous displacement of the mandibular midline** - **Sign of ADD without reduction** ## Midline deviation - **The mandible return to the centered position** - **Indicative of interference during condyle movement** - **Prominent sign of ADD with reduction**   #### Mandibular Movement Evaluation - Assessment of movement smoothness - Assessment of mandibular translation #### Midline Deflection - Continuous displacement of the mandibular midline. - A sign of Anterior Disc Displacement (ADD) without reduction. #### Midline Deviation - The mandible returns to the centered position. - Indicative of interference during condyle movement. - A prominent sign of Anterior Disc Displacement (ADD) with reduction. Clinical photo of an open mouth demonstrating 'Midline deflection'. A white line traces the mandibular midline while a red arrow indicates continuous displacement to the side. The accompanying text describes this as a sign of ADD (Anterior Disc Displacement) without reduction. Clinical photo of an open mouth demonstrating 'Midline deviation'. A white line shows the mandible returning to a centered position after being displaced, while a red line highlights the path of interference. The text explains this is indicative of interference during condyle movement and a prominent sign of ADD with reduction. | | CLOSED | OPEN | | :--- | :--- | :--- | | **NORMAL** | | | | **DISC DISPLACEMENT WITH REDUCTION** | | | | **DISC DISPLACEMENT WITHOUT REDUCTION** | | | Bhargava D, Jain M, Deshpande A, Singh A, Jaiswal J. Temporomandibular joint arthrocentesis for internal derangement with disc displacement without reduction. Journal of maxillofacial and oral surgery. 2015 Jun;14:454-9.  #### Internal Derangement Classifications | Condition | Closed Position | Open Position | | :--- | :--- | :--- | | **Normal** | | | | **Disc Displacement with Reduction** | | | | **Disc Displacement without Reduction** | | | A labeled anatomical diagram illustrating three states of the temporomandibular joint (TMJ) across two jaw positions: CLOSED and OPEN. The rows are labeled 'NORMAL', 'DISC DISPLACEMENT WITH REDUCTION', and 'DISC DISPLACEMENT WITHOUT REDUCTION'. Each cell contains a sketch showing the condyle, articular eminence, and the position of the articular disc relative to the mandible. # Occlusion ## Masticatory Muscles Examination - Palpating **masseter** muscle at rest and clenching - Testing **temporalis** in the same way ### Masseter – Origin and insertion **Masseter** The left masseter muscle (red highlight), partially covered by superficial muscles such as the **platysma** muscle (below) and both the **zygomaticus major** and **minor** muscles. | | | | :--- | :--- | | **Origin** | zygomatic arch and maxillary process of **zygomatic** bone | | **Insertion** | Angle surface of **ramus of mandible**, **coronoid** process | | **Artery** | **masseteric** artery | | **Nerve** | **mandibular** nerve (V3) | | **Actions** | **elevation** (as in closing of the mouth) and **protrusion** of **mandible** |     #### Masseter Muscle Assessment - Palpation of the masseter muscle at rest and during clenching. **Anatomy of the Masseter:** - **Origin:** Zygomatic arch and maxillary process of zygomatic bone. - **Insertion:** Angle surface of ramus of mandible, coronoid process. - **Artery:** Masseteric artery. - **Nerve:** Mandibular nerve (V3). - **Actions:** Elevation (closing of the mouth) and protrusion of mandible. Anatomical diagram of the human head in profile showing the masseter muscle highlighted in red. Labels point to the platysma muscle and zygomaticus major/minor muscles covering the masseter. A table detailing Masseter anatomy with columns for category (Origin, Insertion, Artery, Nerve, Actions) and corresponding anatomical descriptions. Clinical photo showing a gloved hand palpating the masseter muscle on a patient's cheek during examination. Clinical photo showing a gloved hand palpating the mandibular angle region of a patient's face. **Occlusion** - **The University of Western Australia** | **Oral Health Centre of Western Australia** **Masticatory Muscles Examination** - Palpating **masseter** muscle at rest and clenching - Testing **temporalis** in the same way **Temporalis muscle** Origin: **temporal lines** on the **parietal** bone of the skull and the superior temporal surface of the **sphenoid** bone Insertion: **coronoid process** of the mandible and **retromolar fossa** Artery: **deep temporal arteries** Nerve: **deep temporal nerves**, branches of the anterior division of the **mandibular nerve (V3)** Actions: **elevation** and **retraction** of mandible The **temporalis muscle**; the **zygomatic arch** and **masseter** have been removed. #### Temporalis Muscle Assessment - Palpation of the temporalis muscle at rest and during clenching. **Anatomy of the Temporalis:** - **Origin:** Temporal lines on the parietal bone and superior temporal surface of the sphenoid bone. - **Insertion:** Coronoid process of the mandible and retromolar fossa. - **Artery:** Deep temporal arteries. - **Nerve:** Deep temporal nerves (branches of V3). - **Actions:** Elevation and retraction of mandible. Occlusion **THE UNIVERSITY OF WESTERN AUSTRALIA** | **Oral Health Centre of Western Australia** **Masticatory Muscles Examination** ► **Palpating medial pterygoid muscle:** medial to mandibular angle | Category | Details | |---|---| | **Origin** | **deep head:** medial side of **lateral pterygoid plate** behind the upper teeth<br>**superficial head:** **pyramidal process** of palatine bone and **maxillary tuberosity** | | **Insertion** | medial angle of the mandible | | **Artery** | pterygoid branches of **maxillary artery** | | **Nerve** | **mandibular nerve** via **nerve to medial pterygoid** | | **Actions** | elevates mandible, closes **jaw**, helps **lateral pterygoids** in moving the jaw from side to side |   #### Medial Pterygoid Muscle - **Palpation:** Medial to the mandibular angle. **Anatomy:** - **Origin:** - Deep head: Medial side of lateral pterygoid plate. - Superficial head: Pyramidal process of palatine bone and maxillary tuberosity. - **Insertion:** Medial angle of the mandible. - **Artery:** Pterygoid branches of maxillary artery. - **Nerve:** Mandibular nerve via nerve to medial pterygoid. - **Actions:** Elevates mandible, closes jaw, assists lateral pterygoids in side-to-side movement. Anatomical diagram of the skull highlighting the medial pterygoid muscle in red. The illustration shows the deep and superficial heads of the muscle originating from the lateral pterygoid plate and maxillary tuberosity respectively, as described in the OCR text. Extra-oral clinical photograph demonstrating palpation of the medial pterygoid muscle. A gloved hand is pressing on the medial side of the mandibular angle, corresponding to the 'medial to mandibular angle' instruction in the text. <table><tr><td></td><td><b>Origin</b>Superior head: **infratemporal surface of sphenoid bone**. Inferior head: lateral pterygoid plate</td></tr><tr><td></td><td><b>Insertion</b>Superior head: anterior side of the mandibular condyle. Inferior head: pterygoid fovea</td></tr><tr><td></td><td><b>Artery</b> pterygoid branches of maxillary artery</td></tr><tr><td></td><td><b>Nerve</b> lateral pterygoid nerve from mandibular nerve</td></tr><tr><td></td><td><b>Actions</b> depresses and <u>protrudes</u> mandible, side to side movement of mandible</td></tr></table>   #### Lateral Pterygoid Muscle **Anatomy:** - **Origin:** - Superior head: Infratemporal surface of sphenoid bone. - Inferior head: Lateral pterygoid plate. - **Insertion:** - Superior head: Anterior side of the mandibular condyle. - Inferior head: Pterygoid fovea. - **Artery:** Pterygoid branches of maxillary artery. - **Nerve:** Lateral pterygoid nerve from mandibular nerve. - **Actions:** Depresses and protrudes mandible; facilitates side-to-side movement. Anatomical diagram of the lateral pterygoid muscle. The image shows a side view of the skull with the red-colored muscle belly and tendon highlighted against the bone structure. Thin black lines point to specific anatomical landmarks on the muscle. Clinical photograph demonstrating the palpation of the lateral pterygoid muscle. A gloved finger is shown pressing into the deep infratemporal fossa area (highlighted in red) to locate the muscle head, illustrating the procedure mentioned in the text 'Palpating lateral pterygoid muscle'. Occlusion Masticatory Muscles Examination Palpating **suprahyoid muscles** The University of Western Australia | Oral Health Centre of Western Australia    #### Suprahyoid Muscle Palpation Clinical examination includes the palpation of the suprahyoid muscle group to assess function and tenderness. Anatomical diagram illustrating the suprahyoid muscles of the neck and head. Labels point to: Digastric (anterior belly), Geniohyoid, Mylohyoid, Stylohyoid, and Digastric (posterior belly). The illustration shows muscle origins/insertions on the mandible and hyoid bone. Medical illustration of a human skull in lateral view with masticatory muscles highlighted in red to demonstrate their anatomical position relative to the jaw. Clinical photograph demonstrating the procedure for palpating suprahyoid muscles. A clinician wearing white gloves is pressing into the patient's chin area while the patient's mouth is slightly open. Occlusion Masticatory Muscles Examination ► Palpating **suprahyoid muscles** Anterior belly Posterior belly Digastric • Attachments: – The anterior belly arises from the digastric fossa of the mandible. – The posterior belly arises from the mastoid process of the temporal bone. – The two bellies are connected by an intermediate tendon, which is attached to the hyoid bone via a fibrous sling. • Actions: Depresses the mandible and elevates the hyoid bone.    #### Digastric Muscle - **Attachments:** - Anterior belly: Arises from the digastric fossa of the mandible. - Posterior belly: Arises from the mastoid process of the temporal bone. - Connection: The two bellies connect via an intermediate tendon attached to the hyoid bone. - **Actions:** Depresses the mandible and elevates the hyoid bone. Anatomical diagram of the neck and lower face showing the suprahyoid muscles. Labels point to specific muscle bellies: 'Anterior belly' and 'Posterior belly' are explicitly labeled on the digastric muscle structure. The image illustrates the muscular anatomy relevant to the masticatory muscles examination. Clinical photograph demonstrating palpation of the anterior belly of the digastric muscle. A gloved hand is shown pressing into the chin area near the jawline (mandible) where the anterior belly arises. Clinical photograph demonstrating palpation of the posterior belly of the digastric muscle. A gloved hand is shown grasping the back of the jaw/neck region near the ear (mastoid process) where the posterior belly arises. Occlusion THE UNIVERSITY OF WESTERN AUSTRALIA Oral Health Centre of Western Australia Masticatory Muscles Examination ►Palpating suprahyoid muscles Stylohyoid •Attachments: Arises from the styloid process of the temporal bone and attaches to the lateral aspect of the hyoid bone. •Actions: Initiates a swallowing action by pulling the hyoid bone in a posterior and superior direction.  #### Stylohyoid Muscle - **Attachments:** Arises from the styloid process of the temporal bone and attaches to the lateral aspect of the hyoid bone. - **Actions:** Initiates swallowing by pulling the hyoid bone in a posterior and superior direction. Labelled anatomical diagram of the neck showing suprahyoid muscles. Visible labels include 'Digastric (anterior belly)', 'Geniohyoid', 'Mylohyoid', 'Stylohyoid', and 'Digastric (posterior belly)' with lines pointing to respective muscle regions. Occlusion Masticatory Muscles Examination **Palpating suprahyoid muscles** Geniohyoid - **Attachments**: Arises from the inferior mental spine of the mandible. It then travels inferiorly and posteriorly to attach to the hyoid bone. - **Actions**: Depresses the mandible and elevates the hyoid bone. <div style="text-align: center;"> <table> <tr> <td> <br> <img src="..." alt="..." style="display:none;"> </td> <td> <img src="..." alt="..." style="display:none;"> <br> <img src="..." alt="..." style="display:none;"> <br> <img src="..." alt="..." style="display:none;"> <br> <img src="..." alt="..." style="display:none;"> <br> <img src="..." alt="..." style="display:none;"> <br> <img src="..." alt="..." style="display:none;"> <br> <img src="..." alt="..." style="display:none;"> <br> <img src="..." alt="..." style="display:none;"> <br> <img src="..." alt="..." style="display:none;"> </td> </table> </div>  #### Geniohyoid Muscle - **Attachments:** Arises from the inferior mental spine of the mandible; travels inferiorly and posteriorly to attach to the hyoid bone. - **Actions:** Depresses the mandible and elevates the hyoid bone. Anatomical diagram illustrating the suprahyoid muscles. It features labeled callouts for Digastric (anterior and posterior bellies), Geniohyoid, Mylohyoid, and Stylohyoid. The image is accompanied by a caption 'Palpating suprahyoid muscles' from the OCR context. # Occlusion ## Masticatory Muscles Examination ### Palpating suprahyoid muscles **Mylohyoid** • **Attachments** : Originates from the mylohyoid line of the mandible, and attaches onto the hyoid bone. • **Actions** : Elevates the hyoid bone and the floor of the mouth.  #### Mylohyoid Muscle - **Attachments:** Originates from the mylohyoid line of the mandible and attaches onto the hyoid bone. - **Actions:** Elevates the hyoid bone and the floor of the mouth. Anatomical diagram illustrating the suprahyoid muscles of the neck. The illustration shows labeled structures including: 'Digastric (anterior belly)', 'Geniohyoid', 'Mylohyoid', 'Stylohyoid', and 'Digastric (posterior belly)'. The image is sourced from TeachMeAnatomy. Occlusion **Masticatory Muscles Examination** ► Palpating **suprahyoid muscles** Suprahyoid muscles University of Western Australia, Oral Health Centre of Western Australia    #### Suprahyoid Muscles Overview Comprehensive palpation of the suprahyoid muscle group is a standard component of the masticatory muscle examination. Anatomical diagram of the suprahyoid muscles with labeled callouts: Digastric (anterior belly), Geniohyoid, Mylohyoid, Stylohyoid, and Digastric (posterior belly). The illustration shows muscle attachments to the mandible and hyoid bone. Skeletal rendering of the human skull from a lateral view, highlighting the masticatory and suprahyoid musculature in red/orange tones. Shows anatomical context for muscle origin/insertion points. Clinical photograph showing gloved hands palpating the anterior neck region near the chin and submandibular area, demonstrating palpation technique for suprahyoid muscles as described in OCR text. <img>Dental/medical examination images showing occlusion and masticatory muscles testing.<img> Occlusion **The University of Western Australia** | **Oral Health Centre of Western Australia** **Masticatory Muscles Examination** ◦ **Degree of opening:** Opening of less than 40 mm inter-incisally will hinder efficient prosthodontic treatment ◦ **Dynamic movements against resistance** #### Clinical Range of Motion Parameters - **Degree of opening:** An inter-incisal opening of less than 40 mm may hinder efficient prosthodontic treatment. - **Dynamic movements:** Assessment of mandibular movements against resistance. # Occlusion **THE UNIVERSITY OF WESTERN AUSTRALIA** **Range of motion:** **Opening:** 40-50mm **Lateral movements:** 7-15mm **Protrusive:** 7-15mm    #### Normal Range of Motion Values - **Opening:** 40–50 mm - **Lateral movements:** 7–15 mm - **Protrusive:** 7–15 mm Title text 'Occlusion' displayed prominently at the top left of the slide. Logo for The University of Western Australia located in the top right corner. Text-based table listing Range of motion values: Opening (40-50mm), Lateral movements (7-15mm), and Protrusive (7-15mm). # Occlusion Dental Occlusion ## STATIC * Centric occlusion and MIP: long centric or eccentric * Freedom in centric * Extent of posterior tooth support * Angle's classification * Overbite and overjet * Cross bite DYNAMIC * Protrusion * Lateral movements * Canine guidance * Group function * Balanced occlusion * Interferences   #### Static Parameters - Centric occlusion and MIP (long centric or eccentric) - Freedom in centric - Extent of posterior tooth support - Angle's classification - Overbite and overjet - Cross bite #### Dynamic Parameters - Protrusion - Lateral movements: - Canine guidance - Group function - Balanced occlusion - Interferences Clinical photo of a patient's occlusion viewed from the front (anterior view). The image shows both upper and lower teeth in occlusion with a retractor visible. The teeth exhibit signs of wear or discoloration, and the alignment appears to be part of a dental examination context related to static occlusion assessment. Clinical photo of a patient's occlusion viewed from below (posterior/inferior view), showing the tongue and lower dental arch. This perspective is typically used to assess posterior tooth support, overbite, and cross-bite conditions as mentioned in the OCR text.    Figure 4-15: A diagram showing three variations of anterior dental occlusion (labeled A, B, C). It illustrates different incisor relationships with varying horizontal overlap (HO) and vertical overlap (VO), producing different anterior guidance angles (AGA). The visual includes a caption explaining that the anterior guidance between maxillary and mandibular anterior teeth has a direct influence on the direction of mandibular movement. Figure 2-13: A line drawing of a human skull from an anterior view. An inset zoomed-in detail shows teeth in occlusion with an arrow indicating interference. The caption describes a nonworking interference resulting from contact between maxillary facial-facing cusp inclines and mandibular lingual-facing cusp inclines on the nonworking side. Figure 2-12: A line drawing of a human skull from an anterior view. An inset zoomed-in detail shows teeth in occlusion with an arrow indicating interference. The caption describes a working interference occurring between maxillary palatal-facing cusp inclines and mandibular facial-facing cusp inclines on the working side. # Occlusion ## THE UNIVERSITY OF WESTERN AUSTRALIA | Oral Health Centre of Western Australia **THE UNIVERSITY OF** **WESTERN** **AUSTRALIA** **Oral Health Centre** **of Western Australia** Dental Occlusion **Assess:** * Bruxism/clenching * Mobility * **Periodontitis** * Tooth stability * Mechanical failure #### Dental Occlusion Assessment Evaluate the following during examination: - Bruxism/clenching - Mobility - Periodontitis - Tooth stability - Mechanical failure **Occlusion** THE UNIVERSITY OF WESTERN AUSTRALIA Oral Health Centre of Western Australia **Dental Occlusion** **Bruxism** • Worn teeth • Muscle tenderness • Muscle hypertrophy • Cracked teeth • TMJ pain, locking, clicking   #### Clinical Signs of Bruxism - Worn teeth - Muscle tenderness - Muscle hypertrophy - Cracked teeth - TMJ pain, locking, or clicking Clinical photo of a patient's open mouth showing dental occlusion. The image demonstrates signs of bruxism including worn teeth and potential cracks on the anterior incisors. Photo of a man's face with yellow arrows pointing to the jaw muscles (masseter region), illustrating muscle hypertrophy associated with bruxism. # Occlusion ## Dental Occlusion ### Periodontitis ► Alteration of the occlusion with the prime aim of treating periodontitis is not recommended as it lacks supporting evidence ### Mobility ► Increasing mobility that concerns the patient may require occlusal management ► In conjunction with splinting  #### Periodontal Considerations - **Periodontitis:** Altering occlusion specifically to treat periodontitis is not recommended due to lack of evidence. - **Mobility:** Increasing mobility that concerns the patient may require occlusal management, often in conjunction with splinting. Clinical dental radiograph (periapical X-ray) showing the roots of multiple adjacent teeth. The image is pertinent to the 'Mobility' section of the text, demonstrating tooth anatomy and root structures in the context of increasing mobility that may require occlusal management or splinting. **Occlusion** **Dental Occlusion** Fremitus ► Vibration or movement of teeth during light tapping ► Observation of tooth movement against finger placed across the tooth whilst patient taps teeth lightly together ► Significance: Fremitus of teeth indicates deflective contacts #### Fremitus Assessment - **Definition:** Vibration or movement of teeth during light tapping. - **Method:** Observation of tooth movement against a finger placed across the tooth while the patient taps teeth together. - **Significance:** Indicates the presence of deflective contacts. Occlusion **Dental Occlusion** **Tooth mobility** Miller classification (1950): • Degree 0: "physiological" mobility 0.1-0.2 mm horizontal • Degree 1: ⩽ 1 mm horizontal • Degree 2: > 1 mm horizontal • Degree 3: Both horizontal and vertical #### Miller Classification of Tooth Mobility - **Degree 0:** "Physiological" mobility (0.1–0.2 mm horizontal). - **Degree 1:** ≤ 1 mm horizontal mobility. - **Degree 2:** > 1 mm horizontal mobility. - **Degree 3:** Both horizontal and vertical mobility. Occlusion The University of Western Australia | Oral Health Centre of Western Australia **Dental Occlusion** **Tooth stability** * **Posterior deflective contacts** or loss of posterior occlusal support can result in drifting of maxillary incisors * Can result in **open contacts** and food packing #### Tooth Stability and Migration - Posterior deflective contacts or loss of posterior support can result in the drifting of maxillary incisors. - This migration can lead to open contacts and food impaction. **Occlusion** **THE UNIVERSITY OF** **WESTERN** **AUSTRALIA** **Oral Health Centre** **of Western Australia** **Dental Occlusion** **Tooth stability** ▶ Over-eruption of unopposed teeth can be evident ▶ Drifting/tilting  #### Positional Changes - Over-eruption of unopposed teeth. - Drifting or tilting of teeth. Clinical photo of a human mouth showing the lower jaw and teeth. The image demonstrates dental occlusion issues described in the text: 'Over-eruption of unopposed teeth' (evident by the prominent canine tooth) and 'Drifting/tilting' (visible in the alignment of adjacent teeth). The teeth show signs of wear and discoloration. # Occlusion ## Dental Occlusion Mechanical failure Can be due to * Poor restoration design * Lack of occlusal stability   #### Causes of Mechanical Failure Mechanical failure in restorations can be attributed to: - Poor restoration design - Lack of occlusal stability Clinical photo of dental occlusion showing upper and lower teeth in contact. The image demonstrates potential mechanical failure due to poor restoration design or lack of occlusal stability, as referenced in the OCR text. Clinical photo of dental occlusion from a different angle or case, showing misaligned teeth and possible restorations. This supports the concept of mechanical failure in dental occlusion mentioned in the OCR text. Occlusion Dental Occlusion **Vertical dimensions** * **Rest vertical dimension (RVD)** * **Occlusal vertical dimension (OVD)** * **Freeway space (FWS)**   #### Vertical Dimension Definitions - **Rest Vertical Dimension (RVD)** - **Occlusal Vertical Dimension (OVD)** - **Freeway Space (FWS)** Labelled anatomical diagram illustrating Occlusal Vertical Dimension (OVD). Shows a side profile of the jaw with teeth in contact. A blue vertical line connects the chin and forehead to measure the height of the face when muscles are contracted. The label 'Contracted muscles' points to the mandible area. Labelled anatomical diagram illustrating Rest Vertical Dimension (RVD) and Freeway Space (FWS). Shows a side profile of the jaw where teeth are not touching. A blue vertical line measures the distance from chin to forehead. A red bracket labeled 'FWS' indicates the gap between upper and lower teeth. The label 'Muscle tone' points to the relaxed mandible. Occlusion THE UNIVERSITY OF WESTERN AUSTRALIA Oral Health Centre of Western Australia    Clinical photo showing a frontal view of the patient's occlusion with teeth in contact. The upper and lower anterior teeth are visible, demonstrating alignment and bite relationship. Clinical photo showing a close-up of the anterior dentition with a red arrow pointing to the incisal edge of a central incisor, likely indicating an area of concern or specific feature related to occlusion. Clinical photo showing an occlusal view of the maxillary arch with a red arrow pointing to the palatal aspect of a tooth, possibly highlighting a specific anatomical feature or pathology. # Occlusion the university of western australia | oral health centre of western australia   Clinical photo showing a disassembled pink dental denture or occlusal wax-up on a patterned paper background. The image displays two separate components: a larger base section with posterior teeth on the left and a curved anterior segment on the right. Clinical photo showing an assembled dental model with pink acrylic material (likely representing gingiva) seated over a white stone cast of mandibular teeth. This visual demonstrates the fit and positioning of the prosthesis relative to the natural dentition. # Occlusion    Clinical photo of a dental study model showing the occlusion (bite relationship) between upper and lower teeth from an anterior view. The title 'Occlusion' is present in the slide header. Clinical photo of the maxillary (upper) dental cast viewed from above, displaying the arch form and arrangement of teeth. Clinical photo of the mandibular (lower) dental cast viewed from above, displaying the arch form and arrangement of teeth. Occlusion THE UNIVERSITY OF **WESTERN** **AUSTRALIA** Oral Health Centre of Western Australia    Clinical photo of a blue dental study model (cast) showing the occlusal surface of upper teeth arranged in an arch. Clinical photo of a dental cast with a light blue silicone bite registration material applied to the upper jaw portion. Clinical photo demonstrating occlusion using a blue articulator or bite block placed between two dental casts. Occlusion Planning your case: Luxatemp – Mock up THE UNIVERSITY OF WESTERN AUSTRALIA Oral Health Centre of Western Australia  #### Case Planning Use of materials like Luxatemp for creating mock-ups during the planning phase of prosthetic treatment. Clinical comparison photo showing two intraoral views of a patient's dentition. The left image displays the natural teeth with visible discoloration and an amalgam restoration on the lower left molar. The right image demonstrates a 'Luxatemp – Mock up', where the upper anterior teeth have been replaced with translucent resin shells to visualize the proposed aesthetic outcome. Both images show the mouth held open by a clear plastic cheek retractor. Occlusion Luxatemp – Mock up Planning your case: **THE UNIVERSITY OF WESTERN AUSTRALIA** Oral Health Centre of Western Australia   #### Mock-up Procedures Planning your case using Luxatemp mock-ups to visualize and test occlusal changes. Clinical intraoral photograph showing the maxillary and mandibular anterior teeth. The image displays significant dental pathology including a large black restoration or carious lesion on the lower left posterior tooth (viewer's right), discoloration of several upper incisors, and crowding/malposition of the lower central incisors. Clinical intraoral photograph showing the same patient's dentition from a slightly different angle. This view highlights the occlusion between the upper and lower anterior teeth, revealing edge-to-edge or crossbite relationships in the front region, along with generalized wear and staining of the teeth. # Dental Occlusion **THE UNIVERSITY OF** **WESTERN AUSTRALIA** Oral Health Centre of Western Australia ## Criteria for Ideal Occlusion 1) Mandibular stability 2) Axial occlusal load 3) During lateral excursions: no interference in the working side 4) During lateral excursions: disocclusion in the non-working side 5) During protrusion: disocclusion of posterior teeth #### Criteria for Ideal Occlusion 1. Mandibular stability 2. Axial occlusal load 3. No interference on the working side during lateral excursions 4. Disocclusion on the non-working side during lateral excursions 5. Disocclusion of posterior teeth during protrusion Occlusion **Treatment** ► Treatment of occlusal problems is usually provided in conjunction with prosthodontic treatment. ► The choice of which approach should be applied is made at the planning stage before any irreversible work ► Tx will vary according to: • Complexity of treatment • Modifications required • Condition of existing dentition/occlusion • Presence of occlusal abnormalities #### Treatment Planning Considerations Occlusal treatment is typically provided alongside prosthodontic work. The approach must be decided during the planning stage based on: - Complexity of treatment - Required modifications - Condition of existing dentition/occlusion - Presence of occlusal abnormalities # Occlusion **The University of Western Australia | Oral Health Centre of Western Australia** ## Treatment - Treatment of occlusal problems is usually provided in conjunction with prosthodontic treatment. - The choice of which approach should be applied is made at the planning stage before any irreversible work - **Two prosthetic approaches:** **Conformative and Reorganized**  #### Prosthetic Approaches There are two primary approaches to prosthetic treatment: 1. **Conformative** 2. **Reorganized** Clinical photograph of a dental articulator with an occlusal splint or prosthesis mounted on it. The image demonstrates the mechanical setup used for evaluating or planning occlusion treatment, relevant to the text discussing prosthetic approaches (Conformative and Reorganized). Occlusion **THE UNIVERSITY OF** **WESTERN AUSTRALIA** | **Oral Health Centre of Western Australia** ## Conformation Approach ► Provision of restorations in harmony with the existing jaw relationships - According to maximal intercuspal position (MIP) ► Restorations must fit into the existing occlusal scheme ► Following the restoration, the occlusal contacts on the other (unrestored) teeth are unaltered #### Principles of the Conformative Approach - Provision of restorations in harmony with existing jaw relationships. - Restorations are made according to the Maximal Intercuspal Position (MIP). - Restorations must fit into the existing occlusal scheme. - Occlusal contacts on unrestored teeth remain unaltered following treatment. # Occlusion ## Conformance Approach - Most cost-effective restorative method with the least restorative intervention - Most common method applied in restorative dentistry - Applied for single restorations to multiple restorations - Easiest - Safest - Less likely to introduce problems for the tooth, periodontium, muscles and TMJ  #### Advantages of the Conformative Approach - Most cost-effective restorative method. - Requires the least restorative intervention. - Most common method in restorative dentistry. - Applicable for single or multiple restorations. - Easiest and safest method; less likely to introduce new problems to the teeth, periodontium, muscles, or TMJ. Logos of The University of Western Australia and Oral Health Centre of Western Australia. These serve as institutional branding for the slide. Occlusion The University of Western Australia | Oral Health Centre of Western Australia ### Reorganized Approach * **Altering the existing occlusion scheme and establishing an ideal occlusion (or close to ideal occlusion)** * - According to centric relation * **Requires additional stages of designing and establishing a new occlusion before providing the definitive prosthesis (by provisional restorations)** Once the new occlusion is provided, the rest of the treatment is conformative of the new occlusion    #### Principles of the Reorganized Approach - Altering the existing occlusal scheme to establish an ideal (or near-ideal) occlusion. - Restorations are made according to Centric Relation. - Requires additional stages to design and establish the new occlusion (using provisional restorations) before the definitive prosthesis. - Once the new occlusion is established, subsequent treatment conforms to that new scheme. Clinical photo showing a dental cast or model of an upper dental arch with multiple artificial teeth and metal components, illustrating the prosthetic framework. Clinical intraoral photo of the maxillary (upper) arch showing edentulous areas with remaining natural teeth and existing restorations, demonstrating the patient's current occlusal condition before treatment. Clinical intraoral photo of the anterior teeth showing a completed set of prosthetic crowns or denture teeth in proper occlusion, representing the final outcome after establishing the new ideal occlusion scheme. Occlusion Reorganized Approach Indications - An increase in occlusal vertical dimension is indicated - Teeth are significantly out of position (overerupted, tilted or rotated) - History of repeated restoration failures at the existing occlusion scheme - No posterior occlusal contacts at the desired vertical dimension  #### Indications for the Reorganized Approach - An increase in occlusal vertical dimension (OVD) is required. - Teeth are significantly malpositioned (over-erupted, tilted, or rotated). - History of repeated restoration failures within the existing occlusal scheme. - Absence of posterior occlusal contacts at the desired vertical dimension. Institutional logo and branding header featuring the University of Western Australia crest (shield with swan) alongside the text 'THE UNIVERSITY OF WESTERN AUSTRALIA' and the 'Oral Health Centre of Western Australia' name and stylized dragonfly icon. Occlusion **The University of Western Australia** | **Oral Health Centre of Western Australia** **TAKE-HOME MESSAGE** * Through occlusal analysis is mandatory prior to any prosthetic treatment * The patient occlusion should be recorded before any prosthodontic treatment * Conformance treatment is easier and more predictable and should be considered as first treatment option #### Clinical Recommendations - Thorough occlusal analysis is mandatory prior to any prosthetic treatment. - The patient's occlusion should be recorded before starting prosthodontic treatment. - The conformative approach is easier and more predictable; it should be considered the first treatment option. Thank you  Thank you Landscape photo showing a lush green forested valley between steep cliffs with text 'Thank you' in the bottom right corner. [^1]: Original PDF page 1: [[L5. Clinical Exam of Occlusion.pdf#page=1|L5. Clinical Exam of Occlusion, p.1]] [^2]: Original PDF page 2: [[L5. 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