DiagnosticTree/Toothache
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{
"tree_id": "toothache", "region": "Toothache (Myofascial)", "start": "dental-screen-1",
"redflags": {
"emergency": [
{
"id": "rf-e1",
"label": "Ludwig's angina / deep space infection",
"question": "Is there rapidly progressive swelling of the floor of the mouth, submandibular or sublingual region, with fever, difficulty swallowing or breathing, trismus, and systemic illness?",
"rationale": "Ludwig's angina is a life-threatening rapidly spreading cellulitis of the floor of the mouth that can cause airway obstruction. Dental abscess with systemic spread requires immediate medical attention.",
"action": "Call emergency services immediately. This is a surgical emergency."
},
{
"id": "rf-e2",
"label": "Cardiac referred jaw pain",
"question": "Is there jaw or tooth pain associated with exertion — worse during physical activity and easing at rest — with or without chest tightness or arm pain?",
"rationale": "Cardiac ischaemia refers pain to the jaw and lower teeth, particularly on the left side. This must be excluded immediately in any patient with exertional jaw or tooth pain.",
"action": "Call emergency services immediately. Do not proceed with musculoskeletal assessment."
}
],
"urgent": [
{
"id": "rf-u1",
"label": "Temporal arteritis",
"question": "Is the patient aged 50+ with jaw claudication — pain that builds progressively during chewing and eases completely at rest — temporal headache, or scalp tenderness?",
"rationale": "Jaw claudication is pathognomonic for temporal arteritis. Can cause irreversible blindness if untreated. This is fundamentally different from TrP tooth pain which is worsened by jaw use generally, not only during sustained chewing. Same-day ESR required.",
"action": "Same-day GP referral + ESR and CRP. Do not delay for myofascial assessment."
},
{
"id": "rf-u2",
"label": "Osteonecrosis of the jaw",
"question": "Is the patient on bisphosphonates (alendronate, zoledronic acid), denosumab, or anti-angiogenic medication? Is there exposed bone in the mouth or non-healing extraction socket?",
"rationale": "Medication-related osteonecrosis of the jaw (MRONJ) presents as jaw pain and exposed bone. Irreversible if not promptly managed by an oral surgeon.",
"action": "Urgent oral surgery referral. Do not proceed with intraoral assessment."
}
]
},
"nodes": {
"dental-screen-1": {
"type": "rom",
"question": "SAFETY GATE — Before proceeding, confirm the following: Has dental pathology been excluded by clinical examination AND periapical radiograph? Does the tooth hypersensitivity affect MULTIPLE teeth across a zone rather than a single tooth?",
"movement": "Dental exclusion screen",
"direction": "screening",
"clinical_rationale": "Myofascial toothache is a diagnosis of exclusion from dental pathology. The critical distinguishing features are: (1) multiple teeth are hypersensitive across a zone — not one tooth in isolation; (2) periapical radiographs are normal — no caries, abscess, or periapical lucency; (3) the tooth pain is reproduced by palpating a specific TrP in the muscle, not by direct percussion or pulp testing of a single tooth; (4) inactivating the TrP immediately resolves the hypersensitivity. If dental pathology has not been excluded by radiograph, the patient must be assessed by a dentist first. This algorithm is for patients with toothache where dental causes have already been ruled out, OR where the clinician is identifying the myofascial component alongside concurrent dental review.",
"yes": "arch-zone-split-1",
"no": "result-refer-dental"
},
"arch-zone-split-1": {
"type": "choice",
"question": "Which arch and zone best describes the location of the tooth hypersensitivity?",
"clinical_rationale": "The three muscles in this algorithm refer pain to distinct tooth zones that correspond directly to their anatomical location and TrP type. This question routes to the correct muscle with minimal steps. Lower incisor hypersensitivity is specific to the anterior digastric — it is the only muscle known to refer pain to the lower incisors. Upper tooth hypersensitivity in the molar zone affecting both upper AND lower molars points to masseter superficial, which is the only muscle referring to both arches. Upper tooth hypersensitivity across the anterior, middle, or posterior upper arch without lower tooth involvement points to temporalis ATrP₁, ATrP₂, or ATrP₃ respectively — the zone within the upper arch tells the clinician exactly which spoke and which TrP location to palpate.",
"options": [
{
"label": "Lower incisors specifically — the four lower front teeth are hypersensitive",
"sublabel": "Lower incisor sensitivity only; upper teeth not involved or less affected",
"next": "exam-digastric-1"
},
{
"label": "Upper teeth — across the anterior, middle, or posterior zone of the upper arch",
"sublabel": "Upper incisor, premolar, or molar hypersensitivity without lower tooth involvement, OR with upper arch clearly dominant",
"next": "upper-zone-split-1"
},
{
"label": "Both upper AND lower molar teeth — zone hypersensitivity in both arches",
"sublabel": "Upper and lower molars both hypersensitive across a zone; cheek or jaw pain also present",
"next": "exam-masseter-1"
}
]
},
"upper-zone-split-1": {
"type": "choice",
"question": "Within the upper arch — which zone of teeth is most hypersensitive?",
"clinical_rationale": "Temporalis has three attachment TrPs whose referral to the upper teeth maps directly onto the three zones of the dental arch. ATrP₁ (anterior temporal fossa) refers to the upper incisor teeth and along the supraorbital ridge. ATrP₂ (intermediate temporal fossa) refers to the upper premolars and intermediate maxillary teeth plus a finger-like projection to the mid-temple. ATrP₃ (posterior intermediate fibres) refers to the upper posterior molars plus the maxilla and TMJ area. Knowing the tooth zone tells the clinician exactly where to palpate in the temporal fossa — eliminating the need to systematically palpate the entire fan. This direct mapping is one of the most clinically elegant features of the temporalis spoke system.",
"options": [
{
"label": "Upper incisors or canines — the front upper teeth",
"sublabel": "Anterior upper arch; may also have supraorbital pain or eyebrow referral",
"next": "exam-temporalis-atrp1"
},
{
"label": "Upper premolars — intermediate teeth in the upper arch",
"sublabel": "Mid-arch upper teeth; may also have mid-temple pain",
"next": "exam-temporalis-atrp2"
},
{
"label": "Upper molars — back upper teeth; OR maxillary sinus / TMJ area pain alongside",
"sublabel": "Posterior upper arch; may also feel like sinus pressure or deep TMJ pain",
"next": "exam-temporalis-atrp3"
}
]
},
"exam-temporalis-atrp1": {
"type": "examination",
"question": "Does flat palpation of the ANTERIOR temporalis — at ATrP₁, near the musculotendinous junction at the anterior portion of the temporal fossa above the zygomatic arch — reproduce the upper incisor tooth pain or supraorbital referral?",
"exam_type": "palpation",
"landmark": "ATrP₁ is at the anterior musculotendinous junction of the temporalis, near the coronoid process. This is the most anterior spoke. Palpate with firm flat pressure at the anterior temporal fossa. Ask the patient: does this reproduce the familiar incisor tooth pain, sensitivity, or ache? Also ask about supraorbital or eyebrow referral co-occurring with the tooth pain. Confirm that the tooth hypersensitivity responds to all stimuli — heat, cold, percussion, biting pressure — across the incisor zone, not a single tooth. CAUTION: identify the temporal artery by palpating for pulsation before applying firm pressure.",
"positive_finding": "ATrP₁ tenderness reproducing upper incisor tooth pain or supraorbital referral. Zone hypersensitivity confirmed across the incisor-canine zone.",
"muscles_implicated": ["Temporalis ATrP₁"],
"yes": "result-temporalis-atrp1",
"no": "exam-temporalis-atrp2"
},
"exam-temporalis-atrp2": {
"type": "examination",
"question": "Does flat palpation of the INTERMEDIATE temporalis — at ATrP₂, in the middle of the temporal fossa in the intermediate muscle fibres — reproduce the upper premolar or mid-arch tooth pain, or a finger-like referral to the mid-temple?",
"exam_type": "palpation",
"landmark": "ATrP₂ is at the intermediate portion of the musculotendinous junction, in the middle zone of the temporal fossa. Palpate with firm flat pressure in the midportion of the fan. Ask the patient: does this reproduce the familiar premolar or mid-arch tooth pain? A finger-like projection upward to the mid-temple may accompany the tooth referral. CAUTION: identify the temporal artery by palpating for pulsation before applying firm pressure.",
"positive_finding": "ATrP₂ tenderness reproducing upper premolar or intermediate tooth pain. Finger-like mid-temple referral may co-occur.",
"muscles_implicated": ["Temporalis ATrP₂"],
"yes": "result-temporalis-atrp2",
"no": "exam-temporalis-atrp3"
},
"exam-temporalis-atrp3": {
"type": "examination",
"question": "Does flat palpation of the POSTERIOR-INTERMEDIATE temporalis — at ATrP₃, in the posterior portion of the intermediate fibres of the temporal fossa — reproduce the upper molar tooth pain, deep maxillary pain, or TMJ area referral?",
"exam_type": "palpation",
"landmark": "ATrP₃ is at the posterior intermediate musculotendinous junction zone. Palpate with firm flat pressure in the posterior-intermediate zone of the temporal fossa. Deep fibres of this region may refer to the maxilla and TM joint area in addition to the upper posterior molar teeth — distinguishing this from ATrP₂ is by the posterior molar and maxillary referral, not premolar. CAUTION: identify the temporal artery by palpating for pulsation before applying firm pressure.",
"positive_finding": "ATrP₃ tenderness reproducing upper molar tooth pain, deep maxillary pressure, or TMJ area referral.",
"muscles_implicated": ["Temporalis ATrP₃"],
"yes": "result-temporalis-atrp3",
"no": "exam-masseter-1"
},
"exam-masseter-1": {
"type": "examination",
"question": "Does flat or pincer palpation of the superficial masseter — from the zygomatic arch downward to the gonial angle — reproduce the tooth pain and confirm hypersensitivity in both upper AND lower molars?",
"exam_type": "palpation",
"landmark": "Palpate the superficial masseter from the zygomatic arch downward to the gonial angle. The upper anterior TrP zone refers to the upper and lower molar teeth, cheek, infraorbital area, and eyebrow. Confirm: (1) zone tooth hypersensitivity in both upper and lower molars, not a single tooth; (2) sinusitis-like maxillary pain with normal radiographs confirms anterior-superior TrP referral; (3) jaw deviation toward the affected side on slow mouth opening. IMPORTANT: masseter is the only muscle in this algorithm that refers to BOTH upper and lower molar teeth — this bilateral arch involvement is the defining feature.",
"positive_finding": "Masseter TrP tenderness reproducing tooth pain in both upper and lower molar zones. Zone hypersensitivity without dental pathology confirmed.",
"muscles_implicated": ["Masseter (Superficial)"],
"yes": "result-masseter",
"no": "exam-digastric-1"
},
"exam-digastric-1": {
"type": "examination",
"question": "Does palpation of the anterior digastric belly — at the floor of the mouth along the inferior border of the mandible from the symphysis posteriorly — reproduce the lower incisor tooth pain? Is there mandibular deviation on jaw opening?",
"exam_type": "palpation",
"landmark": "Anterior belly: palpate along the inferior border of the mandible from the midline symphysis to the intermediate tendon zone near the hyoid. The patient must keep the jaw completely relaxed. Anterior Digastric Test: place a finger on the lower incisors and ask the patient to open the jaw against mild resistance — pain reproduction confirms anterior belly involvement. Mandibular Deviation Sign: observe whether the mandible deviates toward the TrP side on slow jaw opening. Lower incisor specificity: the anterior digastric is the only muscle known to refer pain specifically to the four lower incisors — upper tooth involvement is minimal or absent.",
"positive_finding": "Anterior belly palpation reproduces lower incisor tooth pain. Mandibular deviation toward the TrP side. Anterior Digastric Test positive.",
"muscles_implicated": ["Digastric (Anterior Belly)"],
"yes": "result-digastric",
"no": "result-overlap"
},
"result-refer-dental": {
"type": "neuro_referral",
"urgency": "urgent",
"title": "Dental Exclusion Required Before Myofascial Assessment",
"body": "Myofascial toothache is a diagnosis of exclusion. Before proceeding with this algorithm, dental pathology must be excluded by clinical examination and periapical radiograph. Single-tooth hypersensitivity — especially to cold, with clear localisation to one tooth — is more likely dental pulpitis or abscess than myofascial referral until proven otherwise. Proceed with this algorithm once dental assessment has been completed and no pathology found, OR if the clinician is confident that multiple-tooth zone hypersensitivity with normal radiographs is already established.",
"action": "Refer to a dentist for periapical radiograph and clinical dental examination before proceeding with myofascial assessment."
},
"result-temporalis-atrp1": {
"type": "result",
"diagnosis": "Temporalis ATrP₁ — Upper Incisor Toothache",
"confidence": "high",
"wiki_page": "Muscle:Temporalis",
"chapter_ref": "Travell & Simons Vol.1 — Ch.9 Temporalis",
"notes": "ATrP₁ at the anterior musculotendinous junction of the temporalis refers pain forward along the supraorbital ridge and downward to the upper incisor teeth. Tooth hypersensitivity to percussion, heat, cold, and biting pressure in the incisor-canine zone without dental pathology is the cardinal feature. This pattern closely mimics dental pulpitis of the upper front teeth and is one of the most common causes of unnecessary dental treatment in this region — unaware clinicians may extirpate pulps or extract perfectly healthy upper incisor teeth. Inactivating ATrP₁ should immediately resolve the incisor tooth hypersensitivity, serving as both treatment and confirmation. Treatment is not complete until upper trapezius and SCM key TrPs have been inactivated — temporalis is frequently their satellite.",
"treatment_hint": "Ischemic compression and spray and stretch with jaw opened to the stretch limit. The temporal artery runs through the muscle — identify it by palpation before injection. Address bruxism and clenching. Treat upper trapezius and SCM first.",
"also_consider": ["Upper Trapezius (key TrP)", "SCM Sternal (key TrP)", "Masseter Superficial"],
"less_likely": [
{ "muscle": "Masseter Superficial", "reason": "Masseter refers to both upper and lower molars — the incisor zone is specific to ATrP₁" },
{ "muscle": "Digastric Anterior", "reason": "Upper incisor hypersensitivity — anterior digastric refers only to LOWER incisors" },
{ "muscle": "Temporalis ATrP₂", "reason": "Incisor zone (not premolar zone) confirmed; ATrP₁ is more anterior in the temporal fossa" }
],
"confirmatory": [
"ATrP₁ tenderness at the anterior temporal fossa reproducing upper incisor tooth pain — the familiar ache, not just local tenderness",
"Zone hypersensitivity: multiple upper incisor teeth sensitive to percussion, heat, cold, and biting — not isolated to one tooth",
"Normal periapical radiographs — no caries, abscess, or periapical lucency",
"Inactivating ATrP₁ immediately resolves or substantially reduces the incisor tooth hypersensitivity",
"Temporal artery confirmed pulsatile — non-pulsatile tender temporal artery requires temporal arteritis exclusion in patients over 50",
"Supraorbital or eyebrow referral may co-occur with the incisor tooth pain — confirms ATrP₁"
],
"satellite_trps": ["Masseter", "SCM (key TrP)", "Upper Trapezius (key TrP)"],
"landing_page_topics": [
"ATrP₁ vs ATrP₂ vs ATrP₃ — spoke patterns and tooth zone mapping",
"Preventing unnecessary dental treatment — pulp extirpation and extraction",
"Temporal artery anatomy and injection caution",
"Iatrogenic activation — cervical traction without occlusal splint",
"Satellite relationship with upper trapezius and SCM"
],
"related_pages": [
{ "label": "Temporalis full page →", "page": "Muscle:Temporalis" },
{ "label": "Upper Trapezius TrPs →", "page": "Muscle:Trapezius/Upper" },
{ "label": "SCM TrP →", "page": "Muscle:Sternocleidomastoid" }
]
},
"result-temporalis-atrp2": {
"type": "result",
"diagnosis": "Temporalis ATrP₂ — Upper Premolar Toothache",
"confidence": "high",
"wiki_page": "Muscle:Temporalis",
"chapter_ref": "Travell & Simons Vol.1 — Ch.9 Temporalis",
"notes": "ATrP₂ at the intermediate musculotendinous junction refers upward in a finger-like projection to the mid-temple and downward to the upper premolars and intermediate maxillary teeth. Tooth hypersensitivity across the premolar zone — percussion, heat, cold, biting — without dental pathology is the cardinal feature. This pattern closely mimics dental pulpitis of the upper premolars and is a common cause of unnecessary treatment in the middle of the upper arch. Inactivating ATrP₂ immediately resolves the premolar hypersensitivity. Treatment is not complete until upper trapezius and SCM key TrPs have been inactivated.",
"treatment_hint": "Ischemic compression and spray and stretch at ATrP₂ in the intermediate temporal fossa. Identify the temporal artery before injection. Treat upper trapezius and SCM first.",
"also_consider": ["Upper Trapezius (key TrP)", "SCM Sternal (key TrP)", "Masseter Superficial", "Temporalis ATrP₁ or ATrP₃ (may co-occur)"],
"less_likely": [
{ "muscle": "Masseter Superficial", "reason": "Premolar zone only, upper arch — masseter refers to both upper and lower molars" },
{ "muscle": "Digastric Anterior", "reason": "Upper premolar hypersensitivity — anterior digastric refers only to lower incisors" },
{ "muscle": "Temporalis ATrP₁", "reason": "Premolar zone (not incisor zone) confirmed; ATrP₂ is in the intermediate temporal fossa" }
],
"confirmatory": [
"ATrP₂ tenderness in the intermediate temporal fossa reproducing upper premolar tooth pain",
"Zone hypersensitivity: multiple upper premolars sensitive to percussion, heat, cold, biting — not isolated to one tooth",
"Normal periapical radiographs",
"Inactivating ATrP₂ immediately resolves premolar hypersensitivity",
"Finger-like mid-temple referral may co-occur with the premolar tooth pain — confirms ATrP₂"
],
"satellite_trps": ["Masseter", "SCM (key TrP)", "Upper Trapezius (key TrP)"],
"landing_page_topics": [
"ATrP₁ vs ATrP₂ vs ATrP₃ — spoke patterns and tooth zone mapping",
"Preventing unnecessary dental treatment",
"Temporal artery anatomy and injection caution",
"Satellite relationship with upper trapezius and SCM"
],
"related_pages": [
{ "label": "Temporalis full page →", "page": "Muscle:Temporalis" },
{ "label": "Upper Trapezius TrPs →", "page": "Muscle:Trapezius/Upper" }
]
},
"result-temporalis-atrp3": {
"type": "result",
"diagnosis": "Temporalis ATrP₃ — Upper Molar Toothache and Maxillary Pain",
"confidence": "high",
"wiki_page": "Muscle:Temporalis",
"chapter_ref": "Travell & Simons Vol.1 — Ch.9 Temporalis",
"notes": "ATrP₃ at the posterior intermediate musculotendinous junction refers to the upper posterior molar teeth and — via its deep fibres — deeply to the maxilla and TMJ area. The maxillary and TMJ referral from ATrP₃ can be confused with deep masseter pain and with true TMJ disorder. Tooth hypersensitivity in the upper molar zone without dental pathology, especially when accompanied by a feeling of deep maxillary pressure, is the cardinal feature. Masseter superficial TrPs must be distinguished — masseter refers to both upper AND lower molars, whereas ATrP₃ refers primarily to the upper molar zone. Inactivating ATrP₃ resolves the upper molar hypersensitivity and often the maxillary and TMJ referral simultaneously. Treatment is not complete until upper trapezius and SCM key TrPs have been inactivated.",
"treatment_hint": "Ischemic compression and spray and stretch at ATrP₃ in the posterior intermediate temporal fossa. Identify the temporal artery before injection. Examine the TMJ lateral pole to confirm the deep TMJ referral is myofascial and not true capsulitis. Treat upper trapezius and SCM first.",
"also_consider": ["Upper Trapezius (key TrP)", "SCM Sternal (key TrP)", "Masseter Superficial", "Masseter Deep"],
"less_likely": [
{ "muscle": "Masseter Superficial", "reason": "Upper molar zone only — if lower molars also hypersensitive, masseter superficial is more likely; ATrP₃ is upper arch only" },
{ "muscle": "Digastric Anterior", "reason": "Upper molar hypersensitivity — anterior digastric refers only to lower incisors" },
{ "muscle": "Temporalis ATrP₂", "reason": "Posterior molar zone (not premolar zone) and maxillary referral confirm ATrP₃" }
],
"confirmatory": [
"ATrP₃ tenderness in the posterior intermediate temporal fossa reproducing upper molar tooth pain or deep maxillary pressure",
"Zone hypersensitivity: multiple upper molars sensitive — not isolated to one tooth",
"Normal periapical radiographs",
"Deep maxillary pressure or TMJ area referral co-occurring with molar pain — confirms deep fibre ATrP₃ involvement",
"Lower molars NOT hypersensitive — if both arches involved, examine masseter superficial"
],
"satellite_trps": ["Masseter", "SCM (key TrP)", "Upper Trapezius (key TrP)"],
"landing_page_topics": [
"ATrP₁ vs ATrP₂ vs ATrP₃ — spoke patterns and tooth zone mapping",
"ATrP₃ vs masseter superficial — upper-only vs both-arch molar distinction",
"ATrP₃ maxillary and TMJ referral — distinction from true TMJ disorder",
"Temporal artery anatomy and injection caution"
],
"related_pages": [
{ "label": "Temporalis full page →", "page": "Muscle:Temporalis" },
{ "label": "Masseter TrP →", "page": "Muscle:Masseter" },
{ "label": "TMJ Screening →", "page": "Pain:TMJ_Screening_Examination" }
]
},
"result-masseter": {
"type": "result",
"diagnosis": "Masseter — Superficial Head Trigger Point",
"confidence": "high",
"wiki_page": "Muscle:Masseter",
"chapter_ref": "Travell & Simons Vol.1 — Ch.8 Masseter",
"notes": "Superficial masseter TrPs are the only source in this algorithm that refers to BOTH upper and lower molar teeth simultaneously. This bilateral arch involvement — zone hypersensitivity distributed across both upper and lower molars without dental pathology — is the defining diagnostic feature. Associated cheek pain, lower jaw aching, sinusitis-like maxillary pain, and eyebrow referral are frequently present alongside the tooth symptoms. Gonial angle tenderness on flat palpation indicates bruxism enthesopathy rather than a primary TrP. Jaw deviation toward the affected side on slow opening is a useful clinical sign. Treatment is not complete until SCM and upper trapezius key TrPs have been inactivated.",
"treatment_hint": "Pincer palpation with one digit inside the mouth and one outside. Spray and stretch, intraoral massage. Address parafunctional habits — clenching and bruxism. Treat SCM and upper trapezius key TrPs first.",
"also_consider": ["Upper Trapezius (key TrP)", "SCM Sternal (key TrP)", "Temporalis ATrP₃", "Masseter Deep"],
"less_likely": [
{ "muscle": "Temporalis ATrP₃", "reason": "Both upper AND lower molars involved — temporalis refers only to the upper arch; lower molar involvement is specific to masseter superficial" },
{ "muscle": "Digastric Anterior", "reason": "Lower molars involved — anterior digastric refers only to lower incisors, not lower molars" }
],
"confirmatory": [
"Zone hypersensitivity in BOTH upper and lower molar teeth — bilateral arch involvement is the defining feature of masseter, absent in temporalis",
"Masseter belly tenderness reproducing the tooth pain — the familiar ache, not just local tenderness",
"Normal periapical radiographs across the molar zone",
"Inactivating the masseter TrP immediately resolves or substantially reduces molar tooth hypersensitivity",
"Jaw deviation toward the affected side on slow opening",
"Sinusitis-like maxillary pain with normal sinus radiographs confirms anterior-superior TrP referral"
],
"satellite_trps": ["Temporalis", "Medial Pterygoid", "Deep Masseter", "SCM (key TrP)", "Upper Trapezius (key TrP)"],
"landing_page_topics": [
"Superficial vs deep masseter TrPs — tooth referral vs tinnitus and ear referral",
"Both-arch molar hypersensitivity — the defining feature of masseter superficial vs temporalis",
"Sinusitis misdiagnosis — normal sinus imaging with masseter referral",
"Gonial angle enthesopathy vs TrP — bruxism indicator",
"Preventing unnecessary molar extractions"
],
"related_pages": [
{ "label": "Temporalis TrP →", "page": "Muscle:Temporalis" },
{ "label": "SCM TrP →", "page": "Muscle:Sternocleidomastoid" },
{ "label": "TMJ Screening →", "page": "Pain:TMJ_Screening_Examination" }
]
},
"result-digastric": {
"type": "result",
"diagnosis": "Digastric — Anterior Belly Trigger Point",
"confidence": "high",
"wiki_page": "Muscle:Digastric",
"chapter_ref": "Travell & Simons Vol.1 — Ch.12 Digastric",
"notes": "The anterior belly of the digastric is the only muscle known to refer pain specifically to the four lower incisor teeth. This lower incisor specificity — with minimal or absent upper tooth involvement — is the cardinal diagnostic feature that separates anterior digastric from all other muscles in this algorithm. The pattern closely mimics dental pulpitis of the lower front teeth, and unnecessary root canals and extractions of perfectly healthy lower incisors have been performed when the muscle was not examined. The anterior belly TrPs develop secondary to masseter TrPs and are part of the masticatory-chain complex — treat masseter first. Mandibular deviation toward the TrP side on jaw opening is a useful clinical sign.",
"treatment_hint": "Treat masseter TrPs first — anterior digastric is their satellite. Spray and stretch. Anterior Digastric Test (resist jaw opening) confirms involvement. Assess hyoid mobility — restricted lateral shift indicates suprahyoid muscle tension. Inactivating the TrP should immediately resolve lower incisor hypersensitivity.",
"also_consider": ["Masseter (key TrP)", "Medial Pterygoid", "Mylohyoid"],
"less_likely": [
{ "muscle": "Temporalis ATrP₁", "reason": "Lower incisor specificity is unique to anterior digastric — temporalis refers to the UPPER incisors, not lower" },
{ "muscle": "Masseter Superficial", "reason": "Lower incisors only — masseter refers to upper and lower MOLARS, not the lower incisors" }
],
"confirmatory": [
"Lower incisor tooth hypersensitivity specifically — the four lower front teeth, without upper tooth zone involvement",
"Anterior belly palpation at the floor of the mouth reproducing lower incisor pain",
"Anterior Digastric Test positive — pain reproduction on resisted jaw opening",
"Mandibular deviation toward the TrP side on slow jaw opening",
"Normal periapical radiographs of the lower incisors",
"Inactivating the anterior belly immediately resolves lower incisor hypersensitivity",
"Masseter TrPs also active on the same side — anterior digastric is almost invariably their satellite"
],
"satellite_trps": ["Masseter (key TrP)", "Medial Pterygoid", "Mylohyoid"],
"landing_page_topics": [
"Lower incisor referral — unique to anterior digastric; preventing unnecessary endodontic treatment",
"Anterior vs posterior belly — different referral patterns, different muscles",
"Hyoid mobility assessment",
"Anterior Digastric Test technique",
"Satellite relationship with masseter"
],
"related_pages": [
{ "label": "Digastric full page →", "page": "Muscle:Digastric" },
{ "label": "Masseter TrP →", "page": "Muscle:Masseter" }
]
},
"result-overlap": {
"type": "overlap",
"text": "Findings are inconclusive. A systematic palpation of all three muscles is indicated. Note that multi-muscle involvement is common — masseter TrPs frequently co-activate temporalis and anterior digastric TrPs simultaneously, producing complex tooth hypersensitivity that spans multiple zones or both arches.",
"screen_these": [
"Temporalis — systematic flat palpation across all three ATrP zones (anterior for incisors, intermediate for premolars, posterior-intermediate for molars); identify the temporal artery first",
"Masseter superficial — pincer palpation from zygomatic arch to gonial angle; confirm whether lower molars are also hypersensitive",
"Digastric anterior — palpation at floor of mouth along inferior mandibular border; Anterior Digastric Test; confirm lower incisor specificity",
"Upper trapezius and SCM — always examine as key TrPs driving temporalis and masseter as satellites"
],
"wiki_page": "Differential:Toothache"
}
},
"broad_differential": [
{
"id": "bd-1",
"condition": "Dental Pulpitis — Irreversible",
"confidence": "common",
"mimics": "Tooth pain with hypersensitivity to heat and cold — directly overlaps with all three muscles in this algorithm",
"distinguishing_feature": "True irreversible pulpitis: pain from a SINGLE tooth that lingers after the thermal stimulus is removed (especially lingering cold sensitivity), localised to one tooth on percussion, radiographic periapical changes, and reproduction by pulp testing of that specific tooth. Myofascial referral: zone hypersensitivity across MULTIPLE teeth, normal radiographs, reproduced by TrP palpation not tooth testing, resolves immediately on TrP inactivation.",
"action": "Periapical radiograph is mandatory. Do not perform irreversible dental treatment (root canal, extraction) on multiple teeth with normal radiographs — this is the classic scenario for myofascial misdiagnosis. Inactivate the TrP and reassess tooth hypersensitivity immediately."
},
{
"id": "bd-2",
"condition": "Dental Abscess — Periapical or Periodontal",
"confidence": "common",
"mimics": "Tooth pain and jaw ache",
"distinguishing_feature": "Periapical abscess: single tooth, percussion tenderness, radiographic periapical lucency, may have sinus tract. Periodontal abscess: localised swelling and suppuration adjacent to one tooth. Neither produces zone hypersensitivity across multiple teeth. True abscess will not resolve with TrP inactivation.",
"action": "Periapical and periodontal examination with radiographs mandatory before any myofascial diagnosis."
},
{
"id": "bd-3",
"condition": "Cracked Tooth Syndrome",
"confidence": "uncommon",
"mimics": "Tooth pain on biting — overlaps with masseter TrP tooth hypersensitivity",
"distinguishing_feature": "Pain on biting that is sharp and momentary, localised to a single tooth, reproduced by biting on a specific cusp with a tooth slooth or cotton roll. Radiographs may be normal. TrP palpation does not reproduce the pain. Does not resolve on TrP inactivation.",
"action": "Refer for dental assessment with tooth slooth testing. May require crown or extraction if crack is severe."
},
{
"id": "bd-4",
"condition": "Trigeminal Neuralgia — V3 Division",
"confidence": "rare",
"mimics": "Lower tooth and jaw pain — overlaps with anterior digastric lower incisor referral",
"distinguishing_feature": "Lancinating electric shock quality lasting seconds to 2 minutes. Trigger zones on the face or inside the mouth. Ceases completely between attacks. Consciousness unimpaired. Never confused with the dull aching quality of myofascial tooth referral.",
"action": "Refer to neurology. MRI to exclude vascular compression. Carbamazepine first-line."
},
{
"id": "bd-5",
"condition": "Sinusitis — Maxillary",
"confidence": "uncommon",
"mimics": "Upper molar and premolar tooth pain with maxillary pressure — overlaps with masseter superficial and temporalis ATrP₃ patterns",
"distinguishing_feature": "True maxillary sinusitis: fever, purulent nasal discharge, radiographic mucosal thickening or opacification, bilateral or unilateral depending on extent. Upper molar teeth may ache from direct sinus floor irritation. Myofascial sinus-like pain: normal sinus radiographs, no fever, no discharge, reproduced by TrP palpation.",
"action": "Sinus radiograph or CT if clinical features (fever, purulent discharge) make true sinusitis plausible. Myofascial treatment first if sinusitis features are absent."
},
{
"id": "bd-6",
"condition": "Temporal Arteritis",
"confidence": "uncommon — critical in over-50s",
"mimics": "Jaw pain on chewing — superficially resembles temporalis and masseter TrP activation by jaw use",
"distinguishing_feature": "Jaw claudication is pathognomonic: pain builds PROGRESSIVELY during sustained chewing and eases completely at rest. This is fundamentally different from TrP tooth pain which is worsened by jaw use in general. Tender non-pulsatile temporal artery on examination. ESR elevated.",
"action": "This is a red flag covered in the checklist. Age over 50 with jaw pain on chewing always requires same-day ESR."
},
{
"id": "bd-7",
"condition": "Cardiac Referred Jaw Pain",
"confidence": "rare — critical",
"mimics": "Lower jaw and tooth pain — may be confused with anterior digastric or masseter referral",
"distinguishing_feature": "Jaw or tooth pain with an exertional component — occurs specifically during physical exertion and eases at rest. May be the only symptom of myocardial ischaemia. Left-sided predominance but not exclusive.",
"action": "This is a red flag covered in the checklist. Any jaw or tooth pain with an exertional component requires urgent cardiac assessment."
},
{
"id": "bd-8",
"condition": "Medication-related Osteonecrosis of the Jaw (MRONJ)",
"confidence": "rare",
"mimics": "Jaw pain and tooth pain in patients on bisphosphonates or denosumab",
"distinguishing_feature": "History of bisphosphonate, denosumab, or anti-angiogenic therapy. Exposed bone in the oral cavity or non-healing extraction socket. Associated infection may cause significant jaw pain.",
"action": "This is a red flag covered in the checklist. Urgent oral surgery referral."
}
]
}