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Table of Contents
Year : 2020  |  Volume : 24  |  Issue : 3  |  Page : 244-250

”Orocrinology”: Seven easy steps!

1 Department of Oral Medicine and Radiology, Amritha School of Dentistry, Amritha Viswa Vidyapeedom, Kochi, Kerala, India
2 Department of Endocrinology, Christian Medical College and Hospital, Ludhiana, Punjab, India
3 Department of Endocrinology, Bharti Hospital, Karnal, Haryana, India

Date of Submission11-Mar-2020
Date of Decision25-Apr-2020
Date of Acceptance25-Apr-2020
Date of Web Publication30-Jun-2020

Correspondence Address:
Jubbin Jagan Jacob
Department of Endocrinology, Christian Medical College and Hospital, Ludhiana, Punjab
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijem.IJEM_119_20

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A complete examination of the oral cavity is a neglected part of physical examination and is not taught in both undergraduate and postgraduate medical training. We believe that a thorough oral examination helps in the identification of a variety of endocrine disorders and so to emphasize this, we have proposed the term “orocrinolgy.” Orocrinology is the art of using a Thorough oral cavity examination to diagnose a variety of adult and pediatric endocrine disorders. Under “orocrinology,” we have highlighted an easy to perform a seven-step technique to perform a complete examination of the oral cavity. The common endocrine-related abnormalities that you might encounter during each of these seven steps is summarized along with the steps. The seven steps start with the examination of the salivary glands, followed by the lips. This is followed by the examination of labial, buccal, alveolar, and gingival mucosa in two steps. The fifth step is the Inspection of the tongue and the base of the mouth followed by the sixth step, which is the evaluation of the palate, uvula, and tonsils. The final seventh step is the examination of the hard structures in the oral cavity, which includes the teeth, mandible, and the maxilla.

Keywords: Endocrine disorders, endocrinology, oral cavity, oral examination, orocinology, seven steps

How to cite this article:
Mathew JE, Varma B, Jacob JJ, Kalra S. ”Orocrinology”: Seven easy steps!. Indian J Endocr Metab 2020;24:244-50

How to cite this URL:
Mathew JE, Varma B, Jacob JJ, Kalra S. ”Orocrinology”: Seven easy steps!. Indian J Endocr Metab [serial online] 2020 [cited 2021 Jul 23];24:244-50. Available from: https://www.ijem.in/text.asp?2020/24/3/244/288542

   Introduction Top

A thorough and comprehensive examination of the oral cavity is an area of physical examination that receives less emphasis in undergraduate and postgraduate medical education. A variety of systemic disorders can be diagnosed by a detailed stepwise examination of the oral cavity. We propose the term “orocrinology” to highlight the importance of thoroughly examining the oral cavity in endocrinology to help in identifying primary hormonal (endocrine) disorders. An understanding of the science and art of “orocrinology” would be of benefit to general practitioners, internists, and practicing endocrinologists. We suggest an easy seven-step technique in this review to complete a thorough oral examination and not miss any findings that may lead to an endocrine diagnosis.

Anatomy of the oral cavity

Anatomically the lips anteriorly limit the oral cavity. The cheeks form the lateral boundary, the floor of the mouth the inferior boundary, the oropharynx the posterior boundary and the palate the superior boundary. A thorough examination of this cavity by a physician requires about few minutes, a good light source, and a pair of gloves for palpation. The mobile phone with its torchlight function is fast replacing the trusty clinical flashlight in providing a ready light source in the clinics and wards! A mouth mirror maybe a useful tool to access hard to visualize areas but is not essential. If the patient is wearing a removable denture, then it should be removed prior to examination.[1]

Step-1. Examination of the salivary glands

Before examining the oral cavity, it is important to start with the salivary glands that are intimately associated with the oral cavity. The parotid gland can be found on the lateral surface of the mandible and it folds itself around the posterior border of the maxilla. Palpation can be done bidigitally from the front or behind the patient. Generally, the gland is soft and not palpable discretely unless the teeth are clenched when the anterior border maybe felt [Figure 1]. When the gland is enlarged, it is important to check for tenderness and to look at the opening of the parotid (Stensen's) duct, which enters into the cheek opposite the maxillary second molar teeth.
Figure 1: Bidigital palpation of the parotid glands from behind the subject

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Submandibular glands are found below the inferior border of the mandible and are best palpated bimanually with one hand in the floor of the mouth and the other hand pressing on the gland from outside. Bilateral painful enlargement of the salivary glands is seen with mumps infection and large unilateral enlargement should signal an alarm for a neoplasm.[1],[2]

Orocrinology of the salivary glands

  1. Causes of bilateral painless enlargement are shown in [Table 1] and include the following endocrine causes.

    1. Growth hormone excess (Acromegaly and Gigantism)
    2. Untreated hypothyroidism
    3. Poorly controlled diabetes mellitus
    4. Sjogren's syndrome associated with renal tubular acidosis (Metabolic bone disease and hypokalemic periodic paralysis).

  2. Intermittent painful enlargement is rarely seen with parotid stones associated with primary hyperparathyroidism.[3]
  3. Inflammation of the salivary glands (sialadenitis) maybe a side effect of high-dose radioactive Iodine 131 therapy for differentiated thyroid cancers.
Table 1: Causes of painless bilateral parotid enlargement (Sialosis)

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Step-2. Examination of the lips

Generally, lips are homogenously pink in color, symmetrical, smooth with a distinctly defined vermillion border. In women, it may be useful to remove any lip coloring before examining the lips. After inspection, both the upper and the lower lips maybe palpated gently using the thumb and the forefinger and rolling downward [Figure 2]. During palpation observe for irregularities, edema, nodularity, tenderness, and growths.[1]
Figure 2: Palpation of the upper lips, after holding the lips between the thumb and the forefinger gently roll it downwards

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Orocrinology of the lips

  1. Large, thick lips are seen in patients with growth hormone excess, and untreated hypothyroidism.
  2. Thin lips with fine wrinkling at the labial edges can be seen in patients with hypopituitarism.[4]
  3. Aphthous ulcers on the inner lips maybe seen in patients with poorly controlled diabetes mellitus (a complete list of causes is given in [Table 2]).
  4. Angular cheilitis is also common with poorly controlled diabetes mellitus.
  5. The orocrinology of cleft lips are discussed below with cleft palate.
  6. Papules or nodules on the lips may represent mucosal neuromas which are seen in MEN-2B.
Table 2: Causes of recurrent aphthous ulcers

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Step-3. Examination of the labial and buccal mucosa

This consists of the mucosa covering the lips and the inner cheeks that is nonkeratinized. Inspection of these areas is done directly using a good light source. Palpation is done again bimanually with one hand inside the mouth the other outside as for mandibular gland examination [Figure 3]a and [Figure 3]b. The mucosa should appear pink and have uniform consistency. Any alterations in color or consistency may require help from an oral medicine professional to accurately characterize the disease.
Figure 3: (a and b) Inspection of the labial and buccal mucosa

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Orocrinology of the labial and buccal mucosa

  1. Burning mouth syndrome by definition is characterized by normal oral mucosa with symptoms of continuous burning in the mouth accompanied by gustatory abnormalities like dysgeusia, parageusia, and subjective xerostomia. The endocrine disorders associated with these are given as follows:[5]

    1. Estrogen deficiency in post menopausal women
    2. Associated with diabetic peripheral neuropathy
    3. Hyperthyroidism [6]
    4. Side effects of common drugs like angiotensin convertase enzyme inhibitors (ACEi).

  2. Candidial infections of the mucosa may present as white lesions over the oral mucosa and tongue and maybe seen in the following endocrine disorders.

    1. Poorly controlled diabetes mellitus [7]
    2. Cushing's syndrome of any etiology including exogenous use of steroids
    3. As part of Autoimmune PolyEndocrinopathy-Candidiasis-Ectodermal Dysplasia (APECED) or Autoimmune Polyglandular Syndrome-1 (APS-1).[5]

  3. Lichenoid reactions are common in patients who are on antihyperglycemic medications, especially when combined with antihypertensives. It may be difficult to differentiate from oral lichen planus and change of medication may alleviate the symptom.
  4. Aphthous ulcers can also be seen over the oral mucosa and may represent poorly controlled diabetes mellitus. A complete list of nonendocrine causes of recurrent aphthous ulcers is given in [Table 2].
  5. Small but numerous pink papules or nodules over the buccal mucosa and the tongue may represent mucosal neuromas which are characteristic of multiple endocrine neoplasm-2B (MEN-2B).
  6. Diffuse or patchy pigmentation of the oral mucosa with sparing of the lips is seen with adrenocorticotropic hormone (ACTH) excess. The pigmentation may not be a direct action of ACTH hormone. This is commonly encountered in Addison's disease, ectopic ACTH producing tumors, and rarely in Nelson's syndrome. Other endocrine and nonendocrine causes of pigmentation are summarized in [Table 3].
  7. Xerostomia, a dull, lusterless mucosa may signify dry mouth or xerostomia that can be seen with uncontrolled hyperglycemia, Sjogren's syndrome, and conditions with chronic hypercalcemia. When no cause is found, it is important to consider drugs, especially oral antihypertensives. A complete list of endocrine and nonendocrine causes is summarized in [Table 4].
Table 3: Causes of oral mucosal hyperpigmentation

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Table 4: Causes of xerostomia

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Step-4. Examination of the gingival and the alveolar mucosa

The gingiva (pink or coral) and the alveolar mucosa (red) are examined for color, texture (usually smooth), swelling or edema, ulceration, recession, spontaneous or bleeding on touch and enlargement. The color of the gingiva in the Indian scenario may not be pink or coral pink, but pale pink with pigmentation. Physiologic pigmentation is restricted to coronal portion of attached gingiva. Palpation is done using a gloved hand to ascertain if the visible enlargement is due to mucosal edema or an underlying bony or fibrous process.[1]

Orocrinology of the gingival and alveolar mucosa

  1. Gingival edema and easy bleeding are seen in patients with Cushing's syndrome of any etiology.
  2. A peculiar type of gingivitis with proliferation of exuberant tissue from gingival margins can accompany poorly controlled type 1 and type 2 diabetes mellitus. The swellings are soft, well demarcated, red, irregular, and hemorrhagic.[5]
  3. High estrogen levels may induce gingivitis in pregnant women. Hyperplasia of the gingiva and pyogenic granuloma affect 1%–5% of pregnant women toward the end of pregnancy and recovers with delivery.[5]
  4. Gingiva becomes sensitive to sex hormones in puberty and can have exaggerated response to local factors which in turn can cause pubertal gingivitis and gingival hyperplasia.
  5. Gingival mucosal pigmentation is seen with ACTH excess syndromes like Addison's disease.

Step-5. Examination of the tongue and base of the mouth

The tongue is best examined with the patient's oral cavity at the examiners eye level and the examiner in front of the patient. After inspection, the tip of the tongue is grasped with a small piece of gauze and slightly moved out [Figure 4]a. This allows you to examine the lateral part of the tongue and the floor of the mouth. During inspection, check color of all the three sides of the tongue (dorsal, ventral, and lateral). In addition, check for plaques, ulcers, thickenings, and changes in papillae. During palpation, check for indurations and tenderness in the tongue.
Figure 4: (a) Inspection of the lateral side of the tongue is done by gripping the tip of the tongue with a small piece of gauze and pulling it to one side. (b) The floor of the mouth is visualized after asking the subject to lift his tongue up

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The floor of the mouth is visualized with a good light source after asking the patient to lift his tongue up [Figure 4]b. No keratinization is seen in the mucosa of the floor of the mouth. Observe the lingual frenum in the middle of the floor attached to the tongue. In addition, the submandibular salivary gland ducts open on both sides of the frenulum.[1],[2]

Orocrinology of the tongue and the floor of the mouth

  1. Macroglossia is a visibly enlarged tongue. Indentations or crenations on the lateral border of the tongue may also signify an enlarged tongue. It is seen in the following conditions:

    1. Growth hormone excess states like Acromegaly and Gigantism
    2. Untreated primary hypothyroidism, especially in children
    3. Beckwith–Wiedemann Syndrome, which also may show macrosomia and hypoglycemia.

  2. Glossitis or inflammation of the tongue with malnutrition and vitamin deficiencies and with Sjogren's syndrome.
  3. Diabetes can cause depapillation of tongue and glossopyrosis; depapillation may be localized or can affect the whole tongue rendering it red and glossy.
  4. Pink papules or nodules over the tongue, especially over the lateral borders may represent mucosal neuromas which are seen in MEN-2B.
  5. A midline soft tissue mass at the back of the tongue may represent an ectopic lingual thyroid.

Step-6. Examination of the palate, uvula, and tonsils

The hard palate is covered with keratinized pink mucosa, which can be directly inspected with good light. During inspection, attention is paid to check for any color changes, ulcerations, and presence of any swelling. Structures to be visualized include the midline raphe and the corrugated ridges that extended from the raphe called the palatal rugae. Palpation is done to confirm findings from inspection. The soft palate is generally only inspected under good lighting for color (pink), presence of ulcerations, thickening, exudates, and petechiae [Figure 5]. When the patient says “ah,” the movement of the soft palate and the uvula is assessed. The tonsils are located on either walls of the pharynx and are generally inspected under light. These areas are generally not palpated unless indicated.[1],[2]
Figure 5: Inspection of the hard palate

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Orocrinology of the palate, uvula, and tonsils

  1. Cleft lip or cleft palate is associated with a large variety of endocrine disorders. A paper from Turkey suggested that over 70% of neonates born with cleft lip/palate have a one or more endocrine deficiency.[8] The commonest endocrine syndrome associated with cleft lip/palate is DiGeorge's syndrome associated with hypoparathyroidism.[9] Isolated midline defects are associated with the idiopathic growth hormone deficiency, multiple congenital pituitary hormone deficiencies (including the recently described RAX and GLI2 mutations),[10],[11] and Kallman's syndrome. Other syndromes associated with clefting and short stature include Apert's syndrome, CHARGE syndrome, Cornelia de Lange syndrome, Pierre Robin syndrome and the rare Abruzzi-Erickson syndrome. Bamforth–Lazarus syndrome is associated with congenital thyroid agenesis, clefts, and choanal atresia.[9] A large list of over 200 specific syndromes are associated with clefting and are labelled syndromic cleft lip and palate. However, over 90% of children with cleft lip and palate have a nonsyndromic variety associated with environmental and genetic risk factors. The environmental factors are given in [Table 5].
  2. High arched palate (Gothic palate) defined as a narrow, tall hard palate is seen in Kallman's syndrome, Turner's syndrome, Bardt Beidl's syndrome, and FGF8 deficiency associated with congenital pituitary hormone deficiency and central diabetes insipidus.[12] A more complete list is given in [Table 6]. It is important to remember that a high arched palate can lead to sleep disordered breathing and obstructive sleep apnea.
  3. Palatal hypertrophy maybe seen in growth hormone excess leading to sleep apnea.
Table 5: Environmental risk factors for nonsyndromic cleft palate and lips

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Table 6: Causes of high arched palate

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Step-7. Examination of the teeth, bones of the oral cavity, and the bite relationship.

The final step in “orocrinology” is the evaluation of the hard structures in the oral cavity. The teeth should be inspected for number, position, spacing between teeth, the color of the teeth, and the intact surfaces [Figure 6]. Dental occlusion is determined by asking the patient to close his mouth and observing the relationship between the upper and lower jaw. A normal bite relationship implies that the anterior teeth on upper jaw are positioned in front of the anterior teeth of the lower jaw. Malocclusion usually implies that either the lower jaw is retrognathic (type 2 malocclusion) or is prognathic (type 3 malocclusion).[1] Masses arising from the mandible and maxillae should be noted and could include a variety of bone tumors. Destruction of the bones of the oral cavity can be secondary to infections and osteonecrosis seen with bisphosphonate use.
Figure 6: Inspection of the teeth should concentrate on number, position, spacing, and color of the teeth

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Orocrinology of teeth, bones of the oral cavity, and the bite relationship

  1. Delayed eruption of teeth is seen in children with congenital hypothyroidism, hypoparathyroidism, isolated growth hormone deficiency, and with congenital multiple pituitary hormone deficiencies. Definition of delayed tooth eruption and common causes are summarized in [Figure 7].
  2. Accelerated eruption of teeth is seen in hyperthyroidism.
  3. Delayed shedding of deciduous teeth is also seen in both congenital or acquired hypopituitarism and hypothyroidism.
  4. Early shedding of deciduous teeth is seen in hyperthyroid children.[3]
  5. Enamel hypoplasia is a defect where enamel is deficient leading to differing manifestations. It can present as a pitting, planar, linear, and localized varieties. Endocrine causes for enamel hypoplasia include chronic hypocalcemia seen in primary hypoparathyroidism, “calcipenic” rickets, osteomalacia, and undiagnosed coeliac disease. It may also accompany bone disease associated with fluorosis.[13] More details of dental disease in fluorosis are given in [Table 7].
  6. Dental abscesses maybe seen with “phosphopenic” rickets.
  7. Dentinogenesis imperfecta (DI) is a dentin dysplasia that causes the teeth to be discolored (blue-gray or yellow-brown) and translucent giving it an opalescent sheen. Type 1 DI is associated with osteogenesis imperfecta and type 2 maybe isolated without any bone disease.[14]
  8. Widely spaced teeth in children maybe a manifestation of untreated hypothyroidism. However, in adults, acromegaly should always be considered.
  9. Crowding of teeth maybe seen in patients with hypopituitarism.[4]
  10. Mandibular prognathism with or without macrognathism (Lantern jaw) is seen in adults with acromegaly. This leads to class 3 malocclusion with a cross bite.
  11. Buccally tilted teeth due to macroglossia also may be seen with acromegaly.
  12. Maxillary prognathism is seen in Cornelia de Lange syndrome. However mandibular retrognathism may be falsely diagnosed as maxillary prognathism. Mandibular retrognathism is associated with Class 2 malocclusion and is seen in congenital hypopituitarism and in patients with Noonan's syndrome. Patients with idiopathic retrognathism are at a higher risk of obstructive sleep apnea syndrome. Retrognathia maybe associated with multiple syndromic causes of short stature including Pierre Robin sequence, Goldenhar syndrome, and Treacher Collins syndrome.[15]
  13. Jaw tumors can be seen with primary hyperparathyroidism as part of bone disease (brown tumors) both in the maxillae or mandible.[16]

    A rare type of autosomal inherited endocrine neoplasia syndrome called hyperparathyroidism jaw tumor syndrome is associated with ossifying fibromas of the jaw along with parathyroid adenomas/carcinoma, and renal and uterine tumors.[17]
  14. Fibrous dysplasia involving the maxillae and the mandible can be present either alone or in combination with endocrinopathy in McCune–Albright syndrome.
  15. Cherubism is a rare genetic condition that causes prominence of the lower portion of the face. The prominence of the lower jaw is related to loss of bone in the mandible where the bone is replaced by expanded fibrous tissue. Usually this is an isolated disorder but may be rarely associated with Noonan's syndrome and Fragile X syndrome.
Figure 7: A diagnostic algorithm for delayed tooth eruption (DTE)

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Table 7: Dean's fluorosis index

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   Conclusions Top

This review summarizes a useful seven-step approach to “orocrinology.” Orocrinology is the art of using a through oral cavity examination to diagnose a variety of adult and pediatric endocrine disorders. Following the above seven steps will help in keeping a mental checklist during the examination and hence not lead to missing any findings.


We are grateful to Dr. Jason Jacob and Dr. Arshdeep Waris for posing for photographs to illustrate the seven-step examination process.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Madani M, Berardi T, Stoopler ET. Anatomic and examination considerations of the oral cavity. Med Clin North Am 2014;98:1225-38.  Back to cited text no. 1
Thomas JE, Bender BS. What to look for after you say 'open wide'. A guide to examination of the oral cavity. Postgrad Med 1993;93:109-10, 113-5.  Back to cited text no. 2
Shamim T. A simple working type classification proposed for oral manifestations of endocrine disorders. J Stomat Occ Med 2015;8:53–4.  Back to cited text no. 3
Atreja G, Atreja SH, Jain N, Sukhija U. Oral manifestations in growth hormone disorders. Indian J Endocrinol Metab 2012;16:381-3.  Back to cited text no. 4
Farag AM. Head and neck manifestations of endocrine disorders. Atlas Oral Maxillofac Surg Clin North Am 2017;25:197-207.  Back to cited text no. 5
Chandna S, Bathla M. Oral manifestations of thyroid disorders and its management. Indian J Endocrinol Metab 2011;15:S113-6.  Back to cited text no. 6
Guggenheimer J, Moore PA, Rossie K, Myers D, Mongelluzzo MB, Block HM, et al. Insulin-dependent diabetes mellitus and oral soft tissue pathologies: II. Prevalence and characteristics of Candida and Candidal lesions. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;89:563-9.  Back to cited text no. 7
Akin MA, Kurtoǧlu S, Sarici D, Akin L, Hatipoǧlu N, Korkmaz L, et al. Endocrine abnormalities of patients with cleft lip and/or cleft palate during the neonatal period. Turk J Med Sci 2014;44:696-702.  Back to cited text no. 8
Burg ML, Chai Y, Yao CA, Magee W 3rd, Figueiredo JC. Epidemiology, etiology, and treatment of isolated cleft palate. Front Physiol 2016;7:67.  Back to cited text no. 9
Brachet C, Kozhemyakina EA, Boros E, Heinrichs C, Balikova I, Soblet J, et al. Truncating RAX mutations: Anophthalmia, hypopituitarism, diabetes insipidus, and cleft palate in mice and men. J Clin Endocrinol Metab 2019;104:2925-30.  Back to cited text no. 10
Martín-Rivada Á, Rodríguez-Contreras FJ, Muñoz-Calvo MT, Güemes M, González-Casado I, Del Pozo JS, et al. A novel GLI2 mutation responsible for congenital hypopituitarism and polymalformation syndrome. Growth Horm IGF Res 2019;44:17-9.  Back to cited text no. 11
Xatzipsalti M, Voutetakis A, Stamoyannou L, Chrousos GP, Kanaka-Gantenbein C. Congenital hypopituitarism: Various genes, various phenotypes. Horm Metab Res 2019;51:81-90.  Back to cited text no. 12
Kanchan T, Machado M, Rao A, Krishan K, Garg AK. Enamel hypoplasia and its role in identification of individuals: A review of literature. Indian J Dent 2015;6:99-102.  Back to cited text no. 13
[PUBMED]  [Full text]  
Beattie ML, Kim JW, Gong SG, Murdoch-Kinch CA, Simmer JP, Hu JC. Phenotypic variation in dentinogenesis imperfecta/dentin dysplasia linked to 4q21. J Dent Res 2006;85:329-33.  Back to cited text no. 14
Jenzer AC, Schlam M. Retrognathia. 2019 Nov 18. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020. Jan-. Available from http://www.ncbi.nlm.nih.gov/books/NBK538303/. [Last accessed on 2020 Feb 25].  Back to cited text no. 15
Jebasingh F, Jacob JJ, Shah A, Paul TV, Seshadri MS. Bilateral maxillary brown tumours as the first presentation of primary hyperparathyroidism. Oral Maxillofac Surg 2008;12:97-100.  Back to cited text no. 16
du Preez H, Adams A, Richards P, Whitley S. Hyperparathyroidism jaw tumour syndrome: A pictoral review. Insights Imaging 2016;7:793-800.  Back to cited text no. 17


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]

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